JP6623015B2 - Plant salt tolerance improver - Google Patents

Description

  The present invention relates to a plant environmental stress tolerance improver. Specifically, the present invention relates to a plant salt tolerance improver containing a histone deacetylase inhibitor as an active ingredient.

  Environmental stresses such as salt stress, drought stress and low temperature stress place significant constraints on plant growth and life support. Since environmental stress also affects photosynthesis and respiration, it causes serious damages in agriculture such as crop quality degradation and yield reduction. Studies on environmental stress responses suggest that there are various environmental stress responsive genes in plants, and that they are involved in acquiring resistance to environmental stress.

Salt stress is a type of environmental stress caused by salt accumulation in soil. Agricultural damage due to salt stress is also increasing with the increase in field area due to the development of irrigation technology, or the immersion of seawater in the field due to tsunami or storm surge. The effects of salt stress in plants can be classified into osmotic stress and ionic stress. Osmotic stress means a phenomenon in which soil osmotic pressure increases due to salt accumulation in soil, water absorption in the roots is restricted, and as a result, water is deficient at the cellular level. Ion stress means phenomena such as a decrease in enzyme activity and inhibition of absorption of inorganic ions such as K ⁺ caused by NaCl, which is the most abundant salt (Non-patent Document 1).

  Environmental stress on plants can be difficult to avoid because it is difficult to remove the causal environmental factors or it costs a lot of money. In particular, in the case of salt stress, it is necessary to demineralize the field where salt is accumulated, but in order to demineralize by irrigation, it is necessary to prepare a drainage facility in the target field. In addition, depending on soil components, salt concentration in the soil may not be sufficiently reduced even when salt removal by irrigation is performed.

  In such a case, there is a possibility that the influence of the environmental stress can be avoided by improving the environmental stress tolerance of the plant itself. Examples of means for improving the environmental stress tolerance of the plant itself include production of a genetically modified plant in which an environmental stress responsive gene is modified, and application of a chemical or biological regulator that improves the environmental stress tolerance.

  For example, Patent Document 1 describes a plant salt tolerance improver comprising as an active ingredient one or more compounds selected from 5-aminolevulinic acid, derivatives thereof and salts thereof, and hemins.

  Patent Document 2 describes a plant growth regulator for cultivated plants, which contains a heterocyclic compound represented by the general formula (I) as an active ingredient. The document describes that the compounds can be used to increase plant salt tolerance.

  Patent Document 3 describes a plant growth promoting and / or salt tolerance improving agent comprising a bacterium belonging to the genus Paenibacillus or a culture supernatant thereof.

Japanese Patent No. 2896963 Japanese Patent Laid-Open No. 2014-88322 JP 2013-75881

Koshiba et al., “Molecular cell biology of plant hormones”, Kodansha, 2006, p. 233-246

  As described above, chemical or biological modulators that improve environmental stress tolerance such as salt stress are known. However, these known chemical or biological regulators have room for improvement in terms of effectiveness and / or cost.

  Therefore, an object of the present invention is to provide an agricultural compound that improves environmental stress tolerance such as salt stress in plants.

  As a result of various studies on means for solving the above problems, the present inventors have found that a specific compound having histone deacetylase inhibitory activity can improve the salt tolerance of plants. Based on the above findings, the present inventors have completed the present invention.

  That is, the gist of the present invention is as follows.

  (1) A plant salt tolerance improver comprising a histone deacetylase inhibitor as an active ingredient.

  (2) The aforementioned histone deacetylase inhibitor is at least one compound having selective inhibitory activity against at least one of plant class I histone deacetylase and class II histone deacetylase (1) The plant salt tolerance improving agent described in 1.

［式中、
Cは、以下、

（式中、
*は、Sとの結合位置を表し、
pは、0〜5の整数であり、
R¹¹は、ハロゲン、シアノ、ニトロ、置換若しくは非置換のアルキル、置換若しくは非置換のアルケニル、置換若しくは非置換のアルキニル、置換若しくは非置換のシクロアルキル、置換若しくは非置換のシクロアルケニル、置換若しくは非置換のシクロアルキニル、置換若しくは非置換のヘテロシクロアルキル、置換若しくは非置換のアリール、置換若しくは非置換のアリールアルキル、置換若しくは非置換のアリールアルケニル、置換若しくは非置換のヘテロアリール、置換若しくは非置換のヘテロアリールアルキル、置換若しくは非置換のアルコキシ、置換若しくは非置換のシクロアルコキシ、置換若しくは非置換のヘテロシクロアルコキシ、置換若しくは非置換のアリールオキシ、置換若しくは非置換のアリールアルキルオキシ、置換若しくは非置換のアリールアルケニルオキシ、置換若しくは非置換のヘテロアリールオキシ、置換若しくは非置換のヘテロアリールアルキルオキシ、置換若しくは非置換のアシル、又は-NR^N11R^N12であり、但しpが2以上の場合、複数のR¹¹は互いに同一又は異なっていてもよく、
R^N11及びR^N12は、互いに独立して、水素、置換若しくは非置換のアルキル、置換若しくは非置換のアルケニル、置換若しくは非置換のアルキニル、置換若しくは非置換のシクロアルキル、置換若しくは非置換のシクロアルケニル、置換若しくは非置換のシクロアルキニル、置換若しくは非置換のヘテロシクロアルキル、置換若しくは非置換のアリール、置換若しくは非置換のアリールアルキル、置換若しくは非置換のアリールアルケニル、置換若しくは非置換のヘテロアリール、置換若しくは非置換のヘテロアリールアルキル、置換若しくは非置換のアルコキシ、置換若しくは非置換のシクロアルコキシ、置換若しくは非置換のヘテロシクロアルコキシ、置換若しくは非置換のアリールオキシ、置換若しくは非置換のアリールアルキルオキシ、置換若しくは非置換のアリールアルケニルオキシ、置換若しくは非置換のヘテロアリールオキシ、置換若しくは非置換のヘテロアリールアルキルオキシ、及び置換若しくは非置換のアシルからなる群より選択される1価基であり、
R²²は、水素、置換若しくは非置換のアルキル、置換若しくは非置換のアルケニル、又は置換若しくは非置換のアルキニルであり、
mは、0〜4の整数であり、
R³²は、ハロゲン、シアノ、ニトロ、置換若しくは非置換のアルキル、置換若しくは非置換のアルケニル、置換若しくは非置換のアルキニル、置換若しくは非置換のシクロアルキル、置換若しくは非置換のシクロアルケニル、置換若しくは非置換のシクロアルキニル、置換若しくは非置換のヘテロシクロアルキル、置換若しくは非置換のアリール、置換若しくは非置換のアリールアルキル、置換若しくは非置換のアリールアルケニル、置換若しくは非置換のヘテロアリール、置換若しくは非置換のヘテロアリールアルキル、置換若しくは非置換のアルコキシ、置換若しくは非置換のシクロアルコキシ、置換若しくは非置換のヘテロシクロアルコキシ、置換若しくは非置換のアリールオキシ、置換若しくは非置換のアリールアルキルオキシ、置換若しくは非置換のアリールアルケニルオキシ、置換若しくは非置換のヘテロアリールオキシ、置換若しくは非置換のヘテロアリールアルキルオキシ、置換若しくは非置換のアシル、又は-NR^N31R^N32であり、但し、mが2以上の場合、複数のR³²は互いに同一又は異なっていてもよく、
R^N31及びR^N32は、互いに独立して、水素、置換若しくは非置換のアルキル、置換若しくは非置換のアルケニル、置換若しくは非置換のアルキニル、置換若しくは非置換のシクロアルキル、置換若しくは非置換のシクロアルケニル、置換若しくは非置換のシクロアルキニル、置換若しくは非置換のヘテロシクロアルキル、置換若しくは非置換のアリール、置換若しくは非置換のアリールアルキル、置換若しくは非置換のアリールアルケニル、置換若しくは非置換のヘテロアリール、置換若しくは非置換のヘテロアリールアルキル、置換若しくは非置換のアルコキシ、置換若しくは非置換のシクロアルコキシ、置換若しくは非置換のヘテロシクロアルコキシ、置換若しくは非置換のアリールオキシ、置換若しくは非置換のアリールアルキルオキシ、置換若しくは非置換のアリールアルケニルオキシ、置換若しくは非置換のヘテロアリールオキシ、置換若しくは非置換のヘテロアリールアルキルオキシ、及び置換若しくは非置換のアシルからなる群より選択される1価基であり、
R⁴¹、R⁴²、R⁴³及びR⁴⁴は、互いに独立して、水素、置換若しくは非置換のアルキル、置換若しくは非置換のアルケニル、置換若しくは非置換のアルキニル、置換若しくは非置換のシクロアルキル、置換若しくは非置換のシクロアルケニル、置換若しくは非置換のシクロアルキニル、置換若しくは非置換のヘテロシクロアルキル、置換若しくは非置換のアリール、置換若しくは非置換のアリールアルキル、置換若しくは非置換のアリールアルケニル、置換若しくは非置換のヘテロアリール、又は置換若しくは非置換のヘテロアリールアルキルであるか、或いは
R⁴¹及びR⁴³は、一緒になって置換若しくは非置換のアルキレン、置換若しくは非置換のアルケニレン、又は置換若しくは非置換のアルキニレンを形成しており、
R⁴⁵は、置換若しくは非置換のアルキレン、置換若しくは非置換のアルケニレン、又は置換若しくは非置換のアルキニレンであり、
R⁵¹は、置換若しくは非置換のアルキル、置換若しくは非置換のアルケニル、置換若しくは非置換のアルキニル、-NR^N51R^N52、-COOH、-COR⁵³、又は-CONR^N53R^N54であり、
R^N51、R^N52、R^N53及びR^N54は、互いに独立して、水素、ヒドロキシル、置換若しくは非置換のアルキル、置換若しくは非置換のアルケニル、置換若しくは非置換のアルキニル、置換若しくは非置換のシクロアルキル、置換若しくは非置換のシクロアルケニル、置換若しくは非置換のシクロアルキニル、置換若しくは非置換のヘテロシクロアルキル、置換若しくは非置換のアリール、置換若しくは非置換のアリールアルキル、置換若しくは非置換のアリールアルケニル、置換若しくは非置換のヘテロアリール、置換若しくは非置換のヘテロアリールアルキル、置換若しくは非置換のアルコキシ、置換若しくは非置換のシクロアルコキシ、置換若しくは非置換のヘテロシクロアルコキシ、置換若しくは非置換のアリールオキシ、置換若しくは非置換のアリールアルキルオキシ、置換若しくは非置換のアリールアルケニルオキシ、置換若しくは非置換のヘテロアリールオキシ、置換若しくは非置換のヘテロアリールアルキルオキシ、置換若しくは非置換のアシル、及び置換若しくは非置換のグリコシルオキシからなる群より選択される1価基であり、
R⁵³は、置換若しくは非置換のアルキル、置換若しくは非置換のアルケニル、置換若しくは非置換のアルキニル、置換若しくは非置換のシクロアルキル、置換若しくは非置換のシクロアルケニル、置換若しくは非置換のシクロアルキニル、置換若しくは非置換のヘテロシクロアルキル、置換若しくは非置換のアリール、置換若しくは非置換のアリールアルキル、置換若しくは非置換のアリールアルケニル、置換若しくは非置換のヘテロアリール、置換若しくは非置換のヘテロアリールアルキル、置換若しくは非置換のアルコキシ、置換若しくは非置換のシクロアルコキシ、置換若しくは非置換のヘテロシクロアルコキシ、置換若しくは非置換のアリールオキシ、置換若しくは非置換のアリールアルキルオキシ、置換若しくは非置換のアリールアルケニルオキシ、置換若しくは非置換のヘテロアリールオキシ、置換若しくは非置換のヘテロアリールアルキルオキシ、又は置換若しくは非置換のアシルである。）
からなる群より選択される一価基、又は水素であり；
Sは、置換若しくは非置換のアルキレン、置換若しくは非置換のアルケニレン、又は置換若しくは非置換のアルキニレン（但し、前記アルキレン、アルケニレン及びアルキニレンは、-O-、-CO-、-NH-、シクロアルキレン、ヘテロシクロアルキレン、アリーレン、ヘテロアリーレンから選択される1個以上の二価基をその鎖中に含んでいてもよい）である二価のスペーサー部分であり；
Zは、置換若しくは非置換のアルキル、置換若しくは非置換のアルケニル、置換若しくは非置換のアルキニル、置換若しくは非置換のアリール、置換若しくは非置換のアリールアルキル、置換若しくは非置換のアリールアルケニル、置換若しくは非置換のヘテロアリール、置換若しくは非置換のヘテロアリールアルキル、置換若しくは非置換のアルコキシ、置換若しくは非置換のシクロアルコキシ、置換若しくは非置換のヘテロシクロアルコキシ、置換若しくは非置換のアリールオキシ、置換若しくは非置換のアリールアルキルオキシ、置換若しくは非置換のアリールアルケニルオキシ、置換若しくは非置換のヘテロアリールオキシ、置換若しくは非置換のヘテロアリールアルキルオキシ、-SH、-S-SH、-COOH、-COR⁴⁸、-CH₂-COR⁴⁸、-COOR⁴⁸、-NR^N41R^N42又は-CONR^N41R^N42であり、但し、前記基は、=N-、-O-、-S-、-S-S-及び-CO-から選択される1〜3個の二価のヘテロ原子又はヘテロ原子基を介して、前記二価のスペーサー部分Sと結合していてもよく、
R⁴⁸は、置換若しくは非置換のアルキル、置換若しくは非置換のアルケニル、置換若しくは非置換のアルキニル、置換若しくは非置換のシクロアルキル、置換若しくは非置換のシクロアルケニル、置換若しくは非置換のシクロアルキニル、置換若しくは非置換のヘテロシクロアルキル、置換若しくは非置換のアリール、置換若しくは非置換のアリールアルキル、置換若しくは非置換のアリールアルケニル、置換若しくは非置換のヘテロアリール、置換若しくは非置換のヘテロアリールアルキル、置換若しくは非置換のアルコキシ、置換若しくは非置換のシクロアルコキシ、置換若しくは非置換のヘテロシクロアルコキシ、置換若しくは非置換のアリールオキシ、置換若しくは非置換のアリールアルキルオキシ、置換若しくは非置換のアリールアルケニルオキシ、置換若しくは非置換のヘテロアリールオキシ、置換若しくは非置換のヘテロアリールアルキルオキシ、又は置換若しくは非置換のアシルであり、
R^N41及びR^N42は、互いに独立して、水素、ヒドロキシル、置換若しくは非置換のアルキル、置換若しくは非置換のアルケニル、置換若しくは非置換のアルキニル、置換若しくは非置換のシクロアルキル、置換若しくは非置換のシクロアルケニル、置換若しくは非置換のシクロアルキニル、置換若しくは非置換のヘテロシクロアルキル、置換若しくは非置換のアリール、置換若しくは非置換のアリールアルキル、置換若しくは非置換のアリールアルケニル、置換若しくは非置換のヘテロアリール、置換若しくは非置換のヘテロアリールアルキル、置換若しくは非置換のアルコキシ、置換若しくは非置換のシクロアルコキシ、置換若しくは非置換のヘテロシクロアルコキシ、置換若しくは非置換のアリールオキシ、置換若しくは非置換のアリールアルキルオキシ、置換若しくは非置換のアリールアルケニルオキシ、置換若しくは非置換のヘテロアリールオキシ、置換若しくは非置換のヘテロアリールアルキルオキシ、及び置換若しくは非置換のアシルからなる群より選択される1価基である。］
で表される化合物若しくはその塩、又はそれらの溶媒和物である、前記（1）又は（2）に記載の植物の耐塩性向上剤。 (3) The histone deacetylase inhibitor is represented by the following formula (A):

[Where:
C is

(Where
* Represents the binding position with S,
p is an integer from 0 to 5,
R ¹¹ is halogen, cyano, nitro, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl, substituted or unsubstituted Substituted cycloalkynyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted arylalkenyl, substituted or unsubstituted heteroaryl, substituted or unsubstituted Heteroarylalkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkoxy, substituted or unsubstituted heterocycloalkoxy, substituted or unsubstituted aryloxy, substituted or unsubstituted arylalkyloxy, substituted Or unsubstituted arylalkenyloxy, substituted or unsubstituted heteroaryloxy, substituted or unsubstituted heteroarylalkyloxy, substituted or unsubstituted acyl, or —NR ^N11 R ^N12 , provided that p is 2 or more A plurality of R ¹¹ may be the same or different from each other;
R ^N11 and R ^N12 each independently represent hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl Substituted or unsubstituted cycloalkynyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted arylalkenyl, substituted or unsubstituted heteroaryl, substituted Or unsubstituted heteroarylalkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkoxy, substituted or unsubstituted heterocycloalkoxy, substituted or unsubstituted aryloxy, substituted or unsubstituted arylalkyloxy, A monovalent group selected from the group consisting of substituted or unsubstituted arylalkenyloxy, substituted or unsubstituted heteroaryloxy, substituted or unsubstituted heteroarylalkyloxy, and substituted or unsubstituted acyl;
R ²² is hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, or substituted or unsubstituted alkynyl,
m is an integer from 0 to 4,
R ³² is halogen, cyano, nitro, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl, substituted or unsubstituted Substituted cycloalkynyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted arylalkenyl, substituted or unsubstituted heteroaryl, substituted or unsubstituted Heteroarylalkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkoxy, substituted or unsubstituted heterocycloalkoxy, substituted or unsubstituted aryloxy, substituted or unsubstituted arylalkyloxy, substituted Or unsubstituted arylalkenyloxy, substituted or unsubstituted heteroaryloxy, substituted or unsubstituted heteroarylalkyloxy, substituted or unsubstituted acyl, or —NR ^N31 R ^N32 , provided that m is 2 or more The plurality of R ³² may be the same or different from each other;
R ^N31 and R ^N32 each independently represent hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl Substituted or unsubstituted cycloalkynyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted arylalkenyl, substituted or unsubstituted heteroaryl, substituted Or unsubstituted heteroarylalkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkoxy, substituted or unsubstituted heterocycloalkoxy, substituted or unsubstituted aryloxy, substituted or unsubstituted arylalkyloxy, A monovalent group selected from the group consisting of substituted or unsubstituted arylalkenyloxy, substituted or unsubstituted heteroaryloxy, substituted or unsubstituted heteroarylalkyloxy, and substituted or unsubstituted acyl;
R ⁴¹ , R ⁴² , R ⁴³ and R ⁴⁴ are independently of each other hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted cycloalkyl, substituted Or unsubstituted cycloalkenyl, substituted or unsubstituted cycloalkynyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted arylalkenyl, substituted or unsubstituted Is substituted heteroaryl, or substituted or unsubstituted heteroarylalkyl, or
R ⁴¹ and R ⁴³ together form a substituted or unsubstituted alkylene, substituted or unsubstituted alkenylene, or substituted or unsubstituted alkynylene,
R ⁴⁵ is substituted or unsubstituted alkylene, substituted or unsubstituted alkenylene, or substituted or unsubstituted alkynylene,
R ⁵¹ is substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, —NR ^N51 R ^N52 , —COOH, —COR ⁵³ , or —CONR ^N53 R ^N54 ,
R ^N51 , R ^N52 , R ^N53 and R ^N54 are independently of one another hydrogen, hydroxyl, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted cycloalkyl Substituted, unsubstituted cycloalkenyl, substituted or unsubstituted cycloalkynyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted arylalkenyl, substituted Or unsubstituted heteroaryl, substituted or unsubstituted heteroarylalkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkoxy, substituted or unsubstituted heterocycloalkoxy, substituted or unsubstituted aryloxy, substituted or Non-replacement Of arylalkyloxy, substituted or unsubstituted arylalkenyloxy, substituted or unsubstituted heteroaryloxy, substituted or unsubstituted heteroarylalkyloxy, substituted or unsubstituted acyl, and substituted or unsubstituted glycosyloxy A monovalent group selected from the group,
R ⁵³ is substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl, substituted or unsubstituted cycloalkynyl, substituted Or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted arylalkenyl, substituted or unsubstituted heteroaryl, substituted or unsubstituted heteroarylalkyl, substituted or Unsubstituted alkoxy, substituted or unsubstituted cycloalkoxy, substituted or unsubstituted heterocycloalkoxy, substituted or unsubstituted aryloxy, substituted or unsubstituted arylalkyloxy, substituted or unsubstituted aryl Lucenyloxy, substituted or unsubstituted heteroaryloxy, substituted or unsubstituted heteroarylalkyloxy, or substituted or unsubstituted acyl. )
A monovalent group selected from the group consisting of, or hydrogen;
S represents a substituted or unsubstituted alkylene, a substituted or unsubstituted alkenylene, or a substituted or unsubstituted alkynylene (wherein the alkylene, alkenylene and alkynylene are -O-, -CO-, -NH-, cycloalkylene, A divalent spacer moiety that may include in its chain one or more divalent groups selected from heterocycloalkylene, arylene, heteroarylene;
Z is substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted arylalkenyl, substituted or unsubstituted Substituted heteroaryl, substituted or unsubstituted heteroarylalkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkoxy, substituted or unsubstituted heterocycloalkoxy, substituted or unsubstituted aryloxy, substituted or unsubstituted Arylalkyloxy, substituted or unsubstituted arylalkenyloxy, substituted or unsubstituted heteroaryloxy, substituted or unsubstituted heteroarylalkyloxy, —SH, —S—SH, —COOH, —COR ⁴⁸ , —CH ₂ -COR ⁴⁸ , -COOR ⁴⁸ , -NR ^N41 R ^N42 or -CONR ^N41 R ^N42 , wherein the group is 1 to 3 divalent heteroatoms selected from = N-, -O-, ^-S- , -SS- and -CO-, or It may be bonded to the divalent spacer moiety S through a heteroatom group,
R ⁴⁸ is substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl, substituted or unsubstituted cycloalkynyl, substituted Or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted arylalkenyl, substituted or unsubstituted heteroaryl, substituted or unsubstituted heteroarylalkyl, substituted or Unsubstituted alkoxy, substituted or unsubstituted cycloalkoxy, substituted or unsubstituted heterocycloalkoxy, substituted or unsubstituted aryloxy, substituted or unsubstituted arylalkyloxy, substituted or unsubstituted aryl Lucenyloxy, substituted or unsubstituted heteroaryloxy, substituted or unsubstituted heteroarylalkyloxy, or substituted or unsubstituted acyl,
R ^N41 and R ^N42 are independently of each other hydrogen, hydroxyl, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted Cycloalkenyl, substituted or unsubstituted cycloalkynyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted arylalkenyl, substituted or unsubstituted heteroaryl Substituted or unsubstituted heteroarylalkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkoxy, substituted or unsubstituted heterocycloalkoxy, substituted or unsubstituted aryloxy, substituted or unsubstituted aryla A monovalent group selected from the group consisting of alkyloxy, substituted or unsubstituted arylalkenyloxy, substituted or unsubstituted heteroaryloxy, substituted or unsubstituted heteroarylalkyloxy, and substituted or unsubstituted acyl. ]
The plant salt tolerance improver according to (1) or (2) above, which is a compound represented by the formula:

［式中、
p及びR¹¹は、前記と同義であり、
R¹²は、水素、置換若しくは非置換のアルキル、置換若しくは非置換のアルケニル、又は置換若しくは非置換のアルキニルであり、
R¹³は、置換若しくは非置換のアルキル、置換若しくは非置換のアルケニル、置換若しくは非置換のアルキニル、-COOH、-COR¹⁴、又は-CONR^N13R^N14であり、
R¹⁴は、置換若しくは非置換のアルキル、置換若しくは非置換のアルケニル、置換若しくは非置換のアルキニル、置換若しくは非置換のシクロアルキル、置換若しくは非置換のシクロアルケニル、置換若しくは非置換のシクロアルキニル、置換若しくは非置換のヘテロシクロアルキル、置換若しくは非置換のアリール、置換若しくは非置換のアリールアルキル、置換若しくは非置換のアリールアルケニル、置換若しくは非置換のヘテロアリール、置換若しくは非置換のヘテロアリールアルキル、置換若しくは非置換のアルコキシ、置換若しくは非置換のシクロアルコキシ、置換若しくは非置換のヘテロシクロアルコキシ、置換若しくは非置換のアリールオキシ、置換若しくは非置換のアリールアルキルオキシ、置換若しくは非置換のアリールアルケニルオキシ、置換若しくは非置換のヘテロアリールオキシ、又は置換若しくは非置換のヘテロアリールアルキルオキシであり、
R^N13及びR^N14は、互いに独立して、水素、ヒドロキシル、置換若しくは非置換のアルキル、置換若しくは非置換のアルケニル、置換若しくは非置換のアルキニル、置換若しくは非置換のシクロアルキル、置換若しくは非置換のシクロアルケニル、置換若しくは非置換のシクロアルキニル、置換若しくは非置換のヘテロシクロアルキル、置換若しくは非置換のアリール、置換若しくは非置換のアリールアルキル、置換若しくは非置換のアリールアルケニル、置換若しくは非置換のヘテロアリール、置換若しくは非置換のヘテロアリールアルキル、置換若しくは非置換のアルコキシ、置換若しくは非置換のシクロアルコキシ、置換若しくは非置換のヘテロシクロアルコキシ、置換若しくは非置換のアリールオキシ、置換若しくは非置換のアリールアルキルオキシ、置換若しくは非置換のアリールアルケニルオキシ、置換若しくは非置換のヘテロアリールオキシ、置換若しくは非置換のヘテロアリールアルキルオキシ、及び置換若しくは非置換のアシルからなる群より選択される1価基である。］
で表される化合物；
（b）式（II）：

［式中、
R²²は、前記と同義であり、
R²¹は、置換若しくは非置換のアルキル、置換若しくは非置換のアルケニル、置換若しくは非置換のアルキニル、-COOH、-COR²³、又は-CONR^N21R^N22であり、
R^N21及びR^N22は、互いに独立して、水素、ヒドロキシル、置換若しくは非置換のアルキル、置換若しくは非置換のアルケニル、置換若しくは非置換のアルキニル、置換若しくは非置換のシクロアルキル、置換若しくは非置換のシクロアルケニル、置換若しくは非置換のシクロアルキニル、置換若しくは非置換のヘテロシクロアルキル、置換若しくは非置換のアリール、置換若しくは非置換のアリールアルキル、置換若しくは非置換のアリールアルケニル、置換若しくは非置換のヘテロアリール、置換若しくは非置換のヘテロアリールアルキル、置換若しくは非置換のアルコキシ、置換若しくは非置換のシクロアルコキシ、置換若しくは非置換のヘテロシクロアルコキシ、置換若しくは非置換のアリールオキシ、置換若しくは非置換のアリールアルキルオキシ、置換若しくは非置換のアリールアルケニルオキシ、置換若しくは非置換のヘテロアリールオキシ、置換若しくは非置換のヘテロアリールアルキルオキシ、及び置換若しくは非置換のアシルからなる群より選択される1価基であり、
R²³は、置換若しくは非置換のアルキル、置換若しくは非置換のアルケニル、置換若しくは非置換のアルキニル、置換若しくは非置換のシクロアルキル、置換若しくは非置換のシクロアルケニル、置換若しくは非置換のシクロアルキニル、置換若しくは非置換のヘテロシクロアルキル、置換若しくは非置換のアリール、置換若しくは非置換のアリールアルキル、置換若しくは非置換のアリールアルケニル、置換若しくは非置換のヘテロアリール、置換若しくは非置換のヘテロアリールアルキル、置換若しくは非置換のアルコキシ、置換若しくは非置換のシクロアルコキシ、置換若しくは非置換のヘテロシクロアルコキシ、置換若しくは非置換のアリールオキシ、置換若しくは非置換のアリールアルキルオキシ、置換若しくは非置換のアリールアルケニルオキシ、置換若しくは非置換のヘテロアリールオキシ、置換若しくは非置換のヘテロアリールアルキルオキシ、又は置換若しくは非置換のアシルである。］
で表される化合物；
（c）式（III）：

［式中、
m及びR³²は、前記と同義であり、
nは、0〜5の整数であり、
R³¹は、ハロゲン、シアノ、ニトロ、置換若しくは非置換のアルキル、置換若しくは非置換のアルケニル、置換若しくは非置換のアルキニル、置換若しくは非置換のシクロアルキル、置換若しくは非置換のシクロアルケニル、置換若しくは非置換のシクロアルキニル、置換若しくは非置換のヘテロシクロアルキル、置換若しくは非置換のアリール、置換若しくは非置換のアリールアルキル、置換若しくは非置換のアリールアルケニル、置換若しくは非置換のヘテロアリール、置換若しくは非置換のヘテロアリールアルキル、置換若しくは非置換のアルコキシ、置換若しくは非置換のシクロアルコキシ、置換若しくは非置換のヘテロシクロアルコキシ、置換若しくは非置換のアリールオキシ、置換若しくは非置換のアリールアルキルオキシ、置換若しくは非置換のアリールアルケニルオキシ、置換若しくは非置換のヘテロアリールオキシ、置換若しくは非置換のヘテロアリールアルキルオキシ、置換若しくは非置換のアシル、又は-NR^N31R^N32であり、但しnが2以上の場合、複数のR³¹はそれぞれ互いに同一又は異なっていてもよく、
R^N31及びR^N32は、前記と同義である。］
で表される化合物；
（d）式（IV）：

［式中、
R⁴¹、R⁴²、R⁴³、R⁴⁴及びR⁴⁵は、前記と同義であり、
R⁴⁶は、置換若しくは非置換のアルキレン、置換若しくは非置換のアルケニレン、又は置換若しくは非置換のアルキニレンであり、
R⁴⁷は、置換若しくは非置換のアルキル、置換若しくは非置換のアルケニル、置換若しくは非置換のアルキニル、置換若しくは非置換のアリール、置換若しくは非置換のアリールアルキル、置換若しくは非置換のアリールアルケニル、置換若しくは非置換のヘテロアリール、置換若しくは非置換のヘテロアリールアルキル、置換若しくは非置換のアルコキシ、置換若しくは非置換のシクロアルコキシ、置換若しくは非置換のヘテロシクロアルコキシ、置換若しくは非置換のアリールオキシ、置換若しくは非置換のアリールアルキルオキシ、置換若しくは非置換のアリールアルケニルオキシ、置換若しくは非置換のヘテロアリールオキシ、置換若しくは非置換のヘテロアリールアルキルオキシ、-SH、-S-SH、-COOH、-COR⁴⁸、-CH₂-COR⁴⁸、-COOR⁴⁸、-NR^N41R^N42又は-CONR^N41R^N42であり、但し、前記基は、=N-、-O-、-S-、-S-S-及び-CO-から選択される1〜3個の二価のヘテロ原子又はヘテロ原子基を介して、R⁴⁶と結合していてもよく、
R⁴⁸、R^N41及びR^N42は、前記と同義である。］
で表される化合物；
（e）式（V）：

［式中、
R⁵¹は、前記と同義であり、
R⁵²は、酸ハロゲン化物、シアノホルミル、カルボキシル、置換若しくは非置換のアルキルカルボニル、置換若しくは非置換のアルケニルカルボニル、置換若しくは非置換のアルキニルカルボニル、置換若しくは非置換のアルコキシカルボニル、置換若しくは非置換のシクロアルコキシカルボニル、又は-CO-NR^N55R^N56であり、
R^N55及びR^N56は、互いに独立して、水素、ヒドロキシル、置換若しくは非置換のアルキル、置換若しくは非置換のアルケニル、置換若しくは非置換のアルキニル、置換若しくは非置換のシクロアルキル、置換若しくは非置換のシクロアルケニル、置換若しくは非置換のシクロアルキニル、置換若しくは非置換のヘテロシクロアルキル、置換若しくは非置換のアリール、置換若しくは非置換のアリールアルキル、置換若しくは非置換のアリールアルケニル、置換若しくは非置換のヘテロアリール、置換若しくは非置換のヘテロアリールアルキル、置換若しくは非置換のアルコキシ、置換若しくは非置換のシクロアルコキシ、置換若しくは非置換のヘテロシクロアルコキシ、置換若しくは非置換のアリールオキシ、置換若しくは非置換のアリールアルキルオキシ、置換若しくは非置換のアリールアルケニルオキシ、置換若しくは非置換のヘテロアリールオキシ、置換若しくは非置換のヘテロアリールアルキルオキシ、置換若しくは非置換のアシル、及び置換若しくは非置換のグリコシルオキシからなる群より選択される1価基である。］
で表される化合物；及び
（f）C₃〜C₈の短鎖脂肪酸；
からなる群より選択される少なくとも1種の化合物若しくはその塩、又はそれらの溶媒和物である、前記（3）に記載の植物の耐塩性向上剤。 (4) The histone deacetylase inhibitor is:
(A) Formula (I):

[Where:
p and R ¹¹ are as defined above,
R ¹² is hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, or substituted or unsubstituted alkynyl;
R ¹³ is substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, —COOH, —COR ¹⁴ , or —CONR ^N13 R ^N14 ;
R ¹⁴ is substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl, substituted or unsubstituted cycloalkynyl, substituted Or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted arylalkenyl, substituted or unsubstituted heteroaryl, substituted or unsubstituted heteroarylalkyl, substituted or Unsubstituted alkoxy, substituted or unsubstituted cycloalkoxy, substituted or unsubstituted heterocycloalkoxy, substituted or unsubstituted aryloxy, substituted or unsubstituted arylalkyloxy, substituted or unsubstituted aryl Lukenyloxy, substituted or unsubstituted heteroaryloxy, or substituted or unsubstituted heteroarylalkyloxy,
R ^N13 and R ^N14 are independently of each other hydrogen, hydroxyl, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted Cycloalkenyl, substituted or unsubstituted cycloalkynyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted arylalkenyl, substituted or unsubstituted heteroaryl Substituted or unsubstituted heteroarylalkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkoxy, substituted or unsubstituted heterocycloalkoxy, substituted or unsubstituted aryloxy, substituted or unsubstituted aryla A monovalent group selected from the group consisting of alkyloxy, substituted or unsubstituted arylalkenyloxy, substituted or unsubstituted heteroaryloxy, substituted or unsubstituted heteroarylalkyloxy, and substituted or unsubstituted acyl. ]
A compound represented by:
(B) Formula (II):

[Where:
R ²² is as defined above,
R ²¹ is substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, —COOH, —COR ²³ , or —CONR ^N21 R ^N22 ;
R ^N21 and R ^N22 each independently represent hydrogen, hydroxyl, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted Cycloalkenyl, substituted or unsubstituted cycloalkynyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted arylalkenyl, substituted or unsubstituted heteroaryl Substituted or unsubstituted heteroarylalkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkoxy, substituted or unsubstituted heterocycloalkoxy, substituted or unsubstituted aryloxy, substituted or unsubstituted aryla A monovalent group selected from the group consisting of alkyloxy, substituted or unsubstituted arylalkenyloxy, substituted or unsubstituted heteroaryloxy, substituted or unsubstituted heteroarylalkyloxy, and substituted or unsubstituted acyl;
R ²³ is substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl, substituted or unsubstituted cycloalkynyl, substituted Or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted arylalkenyl, substituted or unsubstituted heteroaryl, substituted or unsubstituted heteroarylalkyl, substituted or Unsubstituted alkoxy, substituted or unsubstituted cycloalkoxy, substituted or unsubstituted heterocycloalkoxy, substituted or unsubstituted aryloxy, substituted or unsubstituted arylalkyloxy, substituted or unsubstituted aryl Lucenyloxy, substituted or unsubstituted heteroaryloxy, substituted or unsubstituted heteroarylalkyloxy, or substituted or unsubstituted acyl. ]
A compound represented by:
(C) Formula (III):

[Where:
m and R ³² are as defined above,
n is an integer from 0 to 5,
R ³¹ is halogen, cyano, nitro, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl, substituted or unsubstituted Substituted cycloalkynyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted arylalkenyl, substituted or unsubstituted heteroaryl, substituted or unsubstituted Heteroarylalkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkoxy, substituted or unsubstituted heterocycloalkoxy, substituted or unsubstituted aryloxy, substituted or unsubstituted arylalkyloxy, substituted Or unsubstituted arylalkenyloxy, substituted or unsubstituted heteroaryloxy, substituted or unsubstituted heteroarylalkyloxy, substituted or unsubstituted acyl, or -NR ^N31 R ^N32 , provided that n is 2 or more A plurality of R ³¹ may be the same or different from each other;
R ^N31 and R ^N32 have the same ^meanings as described above. ]
A compound represented by:
(D) Formula (IV):

[Where:
R ⁴¹ , R ⁴² , R ⁴³ , R ⁴⁴ and R ⁴⁵ are as defined above,
R ⁴⁶ is substituted or unsubstituted alkylene, substituted or unsubstituted alkenylene, or substituted or unsubstituted alkynylene,
R ⁴⁷ is substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted arylalkenyl, substituted or Unsubstituted heteroaryl, substituted or unsubstituted heteroarylalkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkoxy, substituted or unsubstituted heterocycloalkoxy, substituted or unsubstituted aryloxy, substituted or non-substituted Substituted arylalkyloxy, substituted or unsubstituted arylalkenyloxy, substituted or unsubstituted heteroaryloxy, substituted or unsubstituted heteroarylalkyloxy, —SH, —S—SH, —COOH, —COR ⁴⁸ , — CH ₂ -COR ⁴⁸ , -COOR ⁴⁸ , -NR ^N41 R ^N42 or —CONR ^N41 R ^N42 provided that the group is 1 to 3 divalent heteroatoms selected from ^═N— , —O—, ^—S— , —SS— and —CO—. Or it may be bonded to R ⁴⁶ via a heteroatom group,
R ⁴⁸ , R ^N41 and R ^N42 are as defined above. ]
A compound represented by:
(E) Formula (V):

[Where:
R ⁵¹ is as defined above,
R ⁵² is an acid halide, cyanoformyl, carboxyl, substituted or unsubstituted alkylcarbonyl, substituted or unsubstituted alkenylcarbonyl, substituted or unsubstituted alkynylcarbonyl, substituted or unsubstituted alkoxycarbonyl, substituted or unsubstituted Cycloalkoxycarbonyl, or -CO-NR ^N55 R ^N56 ,
R ^N55 and R ^N56 are independently of each other hydrogen, hydroxyl, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted Cycloalkenyl, substituted or unsubstituted cycloalkynyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted arylalkenyl, substituted or unsubstituted heteroaryl Substituted or unsubstituted heteroarylalkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkoxy, substituted or unsubstituted heterocycloalkoxy, substituted or unsubstituted aryloxy, substituted or unsubstituted aryla Selected from the group consisting of alkyloxy, substituted or unsubstituted arylalkenyloxy, substituted or unsubstituted heteroaryloxy, substituted or unsubstituted heteroarylalkyloxy, substituted or unsubstituted acyl, and substituted or unsubstituted glycosyloxy Is a monovalent group. ]
And (f) a short chain fatty acid of C _{3 to} C ₈ ;
The plant salt tolerance improver according to (3) above, which is at least one compound selected from the group consisting of: a salt thereof, or a solvate thereof.

で表される化合物；
（b）式（II-1）：

で表される化合物；
（c）式（III-1）：

で表される化合物；
（d）式（IV-1）〜（IV-4）：

で表される化合物；及び
（e）式（V-1）：

で表される化合物；
からなる群より選択される少なくとも1種の化合物若しくはその塩、又はそれらの溶媒和物；並びに
（f）酪酸ナトリウム又はその溶媒和物；
からなる群より選択される少なくとも1種の化合物である、前記（4）に記載の植物の耐塩性向上剤。 (5) The histone deacetylase inhibitor is:
(A) Formula (I-1):

A compound represented by:
(B) Formula (II-1):

A compound represented by:
(C) Formula (III-1):

A compound represented by:
(D) Formulas (IV-1) to (IV-4):

(E) Formula (V-1):

A compound represented by:
At least one compound selected from the group consisting of: or a salt thereof, or a solvate thereof; and (f) sodium butyrate or a solvate thereof;
The plant salt tolerance improver according to (4) above, which is at least one compound selected from the group consisting of:

  (6) An agrochemical preparation for improving the salt tolerance of a plant, comprising the plant salt tolerance improver according to any one of (1) to (5) as an active ingredient.

  (7) Agriculture for improving the salt tolerance of plants, comprising the plant salt tolerance improver according to any one of (1) to (5) above and one or more agriculturally acceptable components Chemical composition.

  (8) Applying an agriculturally effective amount of the plant salt tolerance improving agent according to any one of (1) to (5) above to a plant or to a soil, a medium or a culture solution from which the plant grows. A method for improving the salt tolerance of the plant.

  By this invention, it becomes possible to provide the agricultural compound which improves environmental stress tolerance like the salt stress in a plant.

  Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

FIG. 1 is a graph showing the survival rate (%) under salt stress conditions when each test compound is added. FIG. 2A is a diagram showing the phenotype of Arabidopsis plants in a NaCl-added medium supplemented with compounds represented by formulas (III-1) and (I-1). The concentration in the figure is the concentration of each test compound. FIG. 2B is a diagram showing a phenotype of an Arabidopsis plant in a NaCl-added medium to which a compound represented by the formula (II-1) has been added. The concentration in the figure is the concentration of the test compound. FIG. 2C is a diagram showing a phenotype of an Arabidopsis plant in a NaCl-added or non-NaCl-added medium to which a compound represented by the formula (V-1) is added. The concentration in the figure is the concentration of the test compound. FIG. 3A is a diagram showing a phenotype of an Arabidopsis plant in a NaCl-added or non-NaCl-added medium supplemented with sodium butyrate. FIG. 3B is a diagram showing a phenotype of an Arabidopsis plant in a NaCl-added or non-NaCl-added medium to which compounds represented by formulas (IV-1) to (IV-4) are added. FIG. 4 is a diagram showing the phenotype of Arabidopsis plants in a NaCl-added medium to which a compound represented by the formula (III-1) is added.

Hereinafter, preferred embodiments of the present invention will be described in detail.
<1. Environmental stress tolerance improver>
In the present invention, “environmental stress” means stress experienced by a plant due to the external environment of the target plant. In the present invention, environmental stress includes any environmental stress in which resistance to histone deacetylase is increased by inhibiting the activity of histone deacetylase. Examples of the environmental stress that is a subject of the present invention include, but are not limited to, salt stress, drought stress, and low temperature stress. Environmental stress is caused by various external environments depending on suitable growth conditions of the target plant. A person skilled in the art can easily determine specific conditions of the external environment that cause environmental stress based on the target plant.

  In the present invention, “environmental stress tolerance” refers to inability to grow (death), poor growth (for example, whitening or yellowing of plants, reduction of root length, or number of leaves) even under growth conditions that are subject to environmental stress. Reduced), a growth rate, or a trait that can grow normally without substantial adverse effects such as a decrease in plant weight or crop yield. In the present specification, “salt stress resistance” may be described as “salt resistance”. By improving the environmental stress tolerance of a plant according to the present invention, the plant can be grown normally even in an external environment that is adversely affected by the growth of a normal plant.

  In the present invention, “histone deacetylase” or “histone deacetylase” means an enzyme that catalyzes the deacetylation of histones. In the present specification, “histone deacetylase” or “histone deacetylase” may be referred to as “HDAC”. In the present invention, “histone deacetylase inhibitor” or “histone deacetylase inhibitor” means a compound that specifically inhibits the enzyme activity of histone deacetylase. Histone deacetylase is known to be an enzyme responsible for one end of an epigenetic gene regulatory mechanism. The domain region that controls the histone deacetylase activity of the enzyme protein is highly conserved in eukaryotes including plants (Yang and Seto, Nat Rev Mol Cell Biol. 2008 9 (3): 206-18). . Plant histone deacetylases are classified into three classes, class I to III, based on features such as sequence homology (Hollender and Liu, Journal of Integrative Plant Biology 2008, 50 (7): 875- 885). Histone deacetylase inhibitors are also classified according to which class of histone deacetylase has selective inhibitory activity (Bolden et al., Nat Rev Drug Discov. 2006 5 (9): 769- 84). The selectivity of each inhibitor for histone deacetylase in plants is also conserved to some extent from previous studies, as can be inferred from the fact that the domain that controls histone deacetylase activity is conserved among eukaryotes. (Mai et al., J Med Chem. 2005 48: 3344-3353).

  The present inventors have found that specific compounds having histone deacetylase inhibitory activity can improve plant salt tolerance. In the present specification, a compound having a histone deacetylase inhibitory activity may be described as a “histone deacetylase inhibitor”. It is known that certain histone deacetylase inhibitors can be used as antitumor or anticancer agents in animals. In addition, it is known that a specific histone deacetylase inhibitor can be used as a control agent against harmful plant fungi (for example, JP-A-2007-262058). However, it is a novel finding that the present inventors have found that histone deacetylase inhibitors have the effect of improving the tolerance of plants themselves to environmental stresses such as salt stress.

  The present invention relates to a plant environmental stress tolerance improver containing a histone deacetylase inhibitor as an active ingredient. The environmental stress is preferably salt stress, drought stress, or low temperature stress, and more preferably salt stress. By applying a plant environmental stress tolerance improver containing a histone deacetylase inhibitor as an active ingredient to the plant, the plant's environmental stress tolerance such as salt tolerance can be improved. In the present invention, “to improve the environmental stress tolerance of a plant” means that when the environmental stress tolerance improving agent of the present invention is treated to the plant population under the growth conditions that are subjected to the environmental stress described above, the treatment is performed. It means that 60% or more, preferably 70% or more, more preferably 80%, further preferably 90% or more, particularly preferably 100% of the plant population exhibits the environmental stress tolerance described above. The environmental stress tolerance of a plant can be evaluated by the means described below.

  The effects of the plant environmental stress tolerance improver according to the present invention include effects on plant growth itself, such as elongation of leaves or roots, increase in the number of leaves, increase in plant weight or crop yield, greening, or promotion of tillage. Such a growth promoting effect may be included or not included. For example, the environmental stress tolerance improving agent for plants of the present invention can specifically improve the tolerance of plants to environmental stresses such as salt stress while substantially promoting the growth of plants. Or the environmental stress tolerance improvement agent of the plant of this invention can improve the tolerance of the plant specifically with respect to environmental stress like salt stress, without substantially promoting the growth of a plant. Either case is included in the embodiment of the present invention.

In the plant environmental stress tolerance improving agent of the present invention, the histone deacetylase inhibitor is at least one having a selective inhibitory activity against at least one of a class I histone deacetylase and a class II histone deacetylase of a plant. Are preferably the following compounds:
(I) a plant class I histone deacetylase (equivalent to an animal class I histone deacetylase) selective inhibitor;
(Ii) a plant class II histone deacetylase (equivalent to an animal class II histone deacetylase) selective inhibitor;
(Iii) plant class I and II histone deacetylase selective inhibitors; and (iv) plant class I, II and III (equivalent to animal class IV histone deacetylases) histone deacetylase selective inhibitors. ;
More preferably, it is at least one compound selected from the group consisting of: At least one histone deacetylase having selective inhibitory activity against at least one of class I histone deacetylases and class II histone deacetylases among plant histone deacetylases classified into classes of classes I to III By using a ase inhibitor compound, environmental stress tolerance of the plant such as salt tolerance can be particularly improved.

  The histone deacetylase selective inhibitor that can be used in the plant environmental stress tolerance improver of the present invention includes, but is not limited to, the following compounds.

(I) Plant class I histone deacetylase selective inhibitors:
N- [4-[[(2-Aminophenyl) amino] carbonyl] benzyl] carbamic acid (3-pyridinyl) methyl (entinostat, MS-275, represented by the following formula (III-1) Compound);
(Ii) Plant class II histone deacetylase selective inhibitors:
(E) -3- (4-((E) -3- (3-Fluorophenyl) -3-oxoprop-1-en-1-yl) -1-methyl-1H-pyrrol-2-yl) -N -Hydroxyacrylamide (MC1568, a compound represented by the following formula (I-1);
(Iii) Plant class I and II histone deacetylase selective inhibitors:
N-hydroxy-2- [4-({[(1-methyl-1H-indol-3-yl) methyl] amino} methyl) -1-piperidinyl] -5-pyrimidinecarboxamide (quisinostat, JNJ- 26481585, a compound represented by the following formula (II-1)),
Cyclo [-L-2-amino-8-hydroxamide-suberoyl-aminoisobutyryl-L-phenylalanyl-D-prolyl-] (Ky-2, a compound represented by the following formula (IV-1)),
Cyclo [-L-2-amino-7- (2-pyridyldithio) heptanoyl-aminoisobutyryl-L-phenylalanyl-D-prolyl-] (Ky-6, represented by the following formula (IV-2) Compound),
Cyclo [-L-2-amino-8-oxoundecanoyl-aminoisobutyryl-L-phenylalanyl-D-prolyl-] (Ky-9, a compound represented by the following formula (IV-3)) ,
Cyclo [-L-2-amino-7- (2-oxopropylthio) heptanoyl-aminoisobutyryl-L-phenylalanyl-D-prolyl-] (Ky-72, represented by the following formula (IV-4) And (iv) plant class I, II and III histone deacetylase selective inhibitors:
(2E, 4E, 6R) -7- [4- (Dimethylamino) phenyl] -N-hydroxy-4,6-dimethyl-7-oxo-2,4-heptadienamide (trichostatin A, represented by the following formula (V-1 ).

で表される化合物若しくはその塩、又はそれらの溶媒和物であることが好ましい。 In the plant environmental stress tolerance improving agent of the present invention, the histone deacetylase inhibitor is represented by the following formula (A):

Or a salt thereof, or a solvate thereof.

からなる群より選択される一価基、又は水素である。式中、*は、Sとの結合位置を表す。 In formula (A),
C is

A monovalent group selected from the group consisting of: or hydrogen. In the formula, * represents a bonding position with S.

  S represents a substituted or unsubstituted alkylene, a substituted or unsubstituted alkenylene, or a substituted or unsubstituted alkynylene (wherein the alkylene, alkenylene and alkynylene are -O-, -CO-, -NH-, cycloalkylene, A divalent spacer moiety which may contain one or more divalent groups selected from heterocycloalkylene, arylene and heteroarylene in the chain.

Z is substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted arylalkenyl, substituted or unsubstituted Substituted heteroaryl, substituted or unsubstituted heteroarylalkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkoxy, substituted or unsubstituted heterocycloalkoxy, substituted or unsubstituted aryloxy, substituted or unsubstituted Arylalkyloxy, substituted or unsubstituted arylalkenyloxy, substituted or unsubstituted heteroaryloxy, substituted or unsubstituted heteroarylalkyloxy, —SH, —S—SH, —COOH, —COR ⁴⁸ , —CH ₂ -COR ⁴⁸ , -COOR ⁴⁸ , -NR ^N41 R ^N42 or -CONR ^N41 R ^N42 , wherein the group is 1 to 3 divalent heteroatoms selected from = N-, -O-, ^-S- , -SS- and -CO-, or The divalent spacer moiety S may be bonded via a heteroatom group.

In formula (A), p and R ¹¹ , R ²² , m and R ³² , R ⁴¹ , R ⁴² , R ⁴³ , R ⁴⁴ , R ⁴⁵ , R ⁴⁸ , R ^N41 and R ^N42 , and R ⁵¹ are It has a meaning to explain.

［式中、*は、Cとの結合位置を、**は、Zとの結合位置を、それぞれ表す。］からなる群より選択される二価基、n-ブチレン、1-プロピル-n-ブチレン又はn-ペンチレンであることがより好ましい。 S is a substituted or unsubstituted C ₁ -C ₈ alkylene, substituted or unsubstituted C ₂ -C ₈ alkenylene, or substituted or unsubstituted C ₂ -C ₈ alkynylene (provided that the alkylene, alkenylene and alkynylene, -O -, - CO -, - NH-, substituted or unsubstituted C ₃ -C ₈ cycloalkylene, substituted or unsubstituted 3-8 membered heterocycloalkylene, substituted or unsubstituted C ₆ -C ₁₅ arylene Is preferably a divalent spacer moiety which may contain 1 to 5 divalent groups selected from substituted or unsubstituted 5- to 15-membered heteroarylene in the chain), :

[Wherein, * represents a bonding position with C, and ** represents a bonding position with Z. And a divalent group selected from the group consisting of n-butylene, 1-propyl-n-butylene and n-pentylene.

Z is a substituted or unsubstituted C ₁ -C ₅ alkyl, substituted or unsubstituted C ₂ -C ₅ alkenyl, substituted or unsubstituted C ₂ -C ₅ alkynyl, substituted or unsubstituted C ₆ -C ₁₆ aryl , substituted or unsubstituted C ₇ -C ₁₆ arylalkyl, substituted or unsubstituted C ₇ -C ₁₆ arylalkenyl, 5-15 membered substituted or unsubstituted heteroaryl, substituted or unsubstituted 5-15 membered heteroarylalkyl, substituted or unsubstituted C ₁ -C ₅ alkoxy, -SH, -S-SH, -COOH , -COR 48, -CH 2 -COR 48, -COOR 48, -NR N41 R N42 or -CONR is preferably ^N41 R ^N42, a substituted or unsubstituted C ₁ -C ₅ alkyl, substituted or unsubstituted C ₆ -C ₁₆ aryl, substituted or unsubstituted 5-15 membered heteroaryl, -SH, - ^{S-SH, -COOH, -COR 48} , -CH 2 -COR 48, -COOR 48, to be a -NR ^N41 R ^N42 or -CONR ^N41 R ^N42 Preferred. Provided that the group is divalent via a divalent heteroatom or heteroatom group selected from = N-, -O-, -S-, -SS- and -CO-. It may be bonded to the spacer part S. Z is - oxiranyl, -SS- _{(pyridin-2-yl), - S-CH 2 -CO} -CH 3, -S-CH 2 -CO-CF 3, -SH, -SSH, -COOH, -CO -CH ₃ , -CO-CH ₂ -O-CH ₃ , -CO-C ₂ H ₅ , -CO-CH ₂ OH, -COCF ₃ , -COCF ₂ CF ₃ , -COOCH ₃ , -COO-Ph (o -NH ₂ ), -N (OH) -COH, -CONH-OH, -CONH-Ph (o-NH ₂ ), -CONH-Ph (o-OH) or -CONH-Ph (o-SH). More preferably.

で表される化合物；
（b）式（II）：

で表される化合物；
（c）式（III）：

で表される化合物；
（d）式（IV）：

で表される化合物；
（e）式（V）：

で表される化合物；及び
（f）C₃〜C₈の短鎖脂肪酸；
からなる群より選択される少なくとも1種の化合物若しくはその塩、又はそれらの溶媒和物であることがより好ましい。 In the plant environmental stress tolerance improving agent of the present invention, the histone deacetylase inhibitor is:
(A) Formula (I):

A compound represented by:
(B) Formula (II):

A compound represented by:
(C) Formula (III):

A compound represented by:
(D) Formula (IV):

A compound represented by:
(E) Formula (V):

And (f) a short chain fatty acid of C _{3 to} C ₈ ;
More preferably, it is at least one compound selected from the group consisting of: or a salt thereof, or a solvate thereof.

In formula (A) and formula (I),
p is an integer from 0 to 5,
R ¹¹ is halogen, cyano, nitro, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl, substituted or unsubstituted Substituted cycloalkynyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted arylalkenyl, substituted or unsubstituted heteroaryl, substituted or unsubstituted Heteroarylalkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkoxy, substituted or unsubstituted heterocycloalkoxy, substituted or unsubstituted aryloxy, substituted or unsubstituted arylalkyloxy, substituted Or unsubstituted arylalkenyloxy, substituted or unsubstituted heteroaryloxy, substituted or unsubstituted heteroarylalkyloxy, substituted or unsubstituted acyl, or —NR ^N11 R ^N12 , provided that p is 2 or more A plurality of R ¹¹ may be the same or different from each other;
R ^N11 and R ^N12 each independently represent hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl Substituted or unsubstituted cycloalkynyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted arylalkenyl, substituted or unsubstituted heteroaryl, substituted Or unsubstituted heteroarylalkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkoxy, substituted or unsubstituted heterocycloalkoxy, substituted or unsubstituted aryloxy, substituted or unsubstituted arylalkyloxy, A monovalent group selected from the group consisting of substituted or unsubstituted arylalkenyloxy, substituted or unsubstituted heteroaryloxy, substituted or unsubstituted heteroarylalkyloxy, and substituted or unsubstituted acyl;
R ¹² is hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, or substituted or unsubstituted alkynyl;
R ¹³ is substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, —COOH, —COR ¹⁴ , or —CONR ^N13 R ^N14 ;
R ¹⁴ is substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl, substituted or unsubstituted cycloalkynyl, substituted Or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted arylalkenyl, substituted or unsubstituted heteroaryl, substituted or unsubstituted heteroarylalkyl, substituted or Unsubstituted alkoxy, substituted or unsubstituted cycloalkoxy, substituted or unsubstituted heterocycloalkoxy, substituted or unsubstituted aryloxy, substituted or unsubstituted arylalkyloxy, substituted or unsubstituted aryl Lukenyloxy, substituted or unsubstituted heteroaryloxy, or substituted or unsubstituted heteroarylalkyloxy,
R ^N13 and R ^N14 are independently of each other hydrogen, hydroxyl, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted Cycloalkenyl, substituted or unsubstituted cycloalkynyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted arylalkenyl, substituted or unsubstituted heteroaryl Substituted or unsubstituted heteroarylalkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkoxy, substituted or unsubstituted heterocycloalkoxy, substituted or unsubstituted aryloxy, substituted or unsubstituted aryla A monovalent group selected from the group consisting of alkyloxy, substituted or unsubstituted arylalkenyloxy, substituted or unsubstituted heteroaryloxy, substituted or unsubstituted heteroarylalkyloxy, and substituted or unsubstituted acyl.

  p is preferably an integer of 1 to 5, more preferably an integer of 1 to 2, and even more preferably 1.

R ¹¹ is halogen, cyano, nitro, substituted or unsubstituted C ₁ -C ₅ alkyl, substituted or unsubstituted C ₂ -C ₅ alkenyl, substituted or unsubstituted C ₂ -C ₅ alkynyl, substituted or unsubstituted C ₁ -C ₅ alkoxy, substituted or unsubstituted C ₁ -C ₅ acyl, or is preferably -NR ^N11 R ^N12, halogen, substituted or unsubstituted C ₁ -C ₅ alkyl, substituted or unsubstituted Is more preferably C ₂ -C ₅ alkenyl, or substituted or unsubstituted C ₂ -C ₅ alkynyl, further preferably halogen, and particularly preferably fluorine.

R ^N11 and R ^N12 are independently of one another, hydrogen, substituted or unsubstituted C ₁ -C ₅ alkyl, substituted or unsubstituted C ₂ -C ₅ alkenyl, substituted or unsubstituted C ₂ -C ₅ alkynyl, And a monovalent group selected from the group consisting of substituted or unsubstituted C _{1 to} C ₅ alkoxy, and more preferably hydrogen.

R ¹² is hydrogen, substituted or unsubstituted C ₁ -C ₅ alkyl, preferably a substituted or unsubstituted C ₂ -C ₅ alkenyl, or substituted or unsubstituted C ₂ -C ₅ alkynyl, hydrogen, or more preferably substituted or unsubstituted C ₁ -C ₅ alkyl, more preferably methyl.

R ¹³ is preferably —COOH, —COR ¹⁴ , or —CONR ^N13 R ^N14 , more preferably —CONR ^N13 R ^N14 , and further preferably —CONH—OH.

R ¹⁴ is a substituted or unsubstituted C ₁ -C ₅ alkyl, substituted or unsubstituted C ₂ -C ₅ alkenyl, substituted or unsubstituted C ₂ -C ₅ alkynyl, or a substituted or unsubstituted C ₁ -C It is preferably ₅ alkoxy, more preferably substituted or unsubstituted C ₁ -C ₅ alkyl, and even more preferably methyl.

R ^N13 and R ^N14 are independently of one another, hydrogen, hydroxyl, a substituted or unsubstituted C ₁ -C ₅ alkyl, substituted or unsubstituted C ₂ -C ₅ alkenyl, substituted or unsubstituted C ₂ -C ₅ alkynyl is preferably a monovalent group selected from the group consisting of substituted or unsubstituted C ₁ -C ₅ alkoxy, and substituted or unsubstituted C ₁ -C ₅ acyl, hydrogen, hydroxyl, substituted or unsubstituted C ₁ -C ₅ alkyl, and more preferably a monovalent group selected from the group consisting of substituted or unsubstituted C ₁ -C ₅ alkoxy, R ^N13 is hydrogen, and R ^N14 is a hydroxyl More preferably it is.

In formula (A) and formula (II),
R ²¹ is substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, —COOH, —COR ²³ , or —CONR ^N21 R ^N22 ;
R ^N21 and R ^N22 each independently represent hydrogen, hydroxyl, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted Cycloalkenyl, substituted or unsubstituted cycloalkynyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted arylalkenyl, substituted or unsubstituted heteroaryl Substituted or unsubstituted heteroarylalkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkoxy, substituted or unsubstituted heterocycloalkoxy, substituted or unsubstituted aryloxy, substituted or unsubstituted aryla A monovalent group selected from the group consisting of alkyloxy, substituted or unsubstituted arylalkenyloxy, substituted or unsubstituted heteroaryloxy, substituted or unsubstituted heteroarylalkyloxy, and substituted or unsubstituted acyl;
R ²² is hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, or substituted or unsubstituted alkynyl,
R ²³ is substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl, substituted or unsubstituted cycloalkynyl, substituted Or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted arylalkenyl, substituted or unsubstituted heteroaryl, substituted or unsubstituted heteroarylalkyl, substituted or Unsubstituted alkoxy, substituted or unsubstituted cycloalkoxy, substituted or unsubstituted heterocycloalkoxy, substituted or unsubstituted aryloxy, substituted or unsubstituted arylalkyloxy, substituted or unsubstituted aryl Lucenyloxy, substituted or unsubstituted heteroaryloxy, substituted or unsubstituted heteroarylalkyloxy, or substituted or unsubstituted acyl.

R ²¹ is preferably —COOH, —COR ²³ , or —CONR ^N21 R ^N22 , more preferably —CONR ^N21 R ^N22 , and further preferably —CONH—OH.

R ²² is preferably hydrogen, substituted or unsubstituted C ₁ -C ₅ alkyl, and more preferably methyl.

R ²³ is substituted or unsubstituted C ₁ -C ₅ alkyl, substituted or unsubstituted C ₂ -C ₅ alkenyl, substituted or unsubstituted C ₂ -C ₅ alkynyl, or substituted or unsubstituted C ₁ -C It is preferably ₅ alkoxy, more preferably substituted or unsubstituted C ₁ -C ₅ alkyl, and even more preferably methyl.

R ^N21 and R ^N22 are independently of one another, hydrogen, hydroxyl, a substituted or unsubstituted C ₁ -C ₅ alkyl, substituted or unsubstituted C ₂ -C ₅ alkenyl, substituted or unsubstituted C ₂ -C ₅ alkynyl is preferably a monovalent group selected from the group consisting of substituted or unsubstituted C ₁ -C ₅ alkoxy, and substituted or unsubstituted C ₁ -C ₅ acyl, hydrogen, hydroxyl, substituted or unsubstituted Is more preferably a monovalent group selected from the group consisting of C ₁ -C ₅ alkyl, and substituted or unsubstituted C ₁ -C ₅ alkoxy, R ^N21 is hydrogen and R ^N22 is hydroxyl More preferably it is.

In formula (A) and formula (III),
n is an integer from 0 to 5,
m is an integer from 0 to 4,
R ³¹ and R ³² are independently of each other halogen, cyano, nitro, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted Substituted cycloalkenyl, substituted or unsubstituted cycloalkynyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted arylalkenyl, substituted or unsubstituted Heteroaryl, substituted or unsubstituted heteroarylalkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkoxy, substituted or unsubstituted heterocycloalkoxy, substituted or unsubstituted aryloxy, substituted or unsubstituted aryl Le alkyloxy, substituted or unsubstituted aryl alkenyloxy, substituted or unsubstituted heteroaryloxy, substituted or unsubstituted heteroaryl alkyloxy, substituted or unsubstituted acyl, or a -NR ^N31 R ^N32, where n Or when m is 2 or more, the plurality of R ³¹ or R ³² may be the same or different from each other;
R ^N31 and R ^N32 each independently represent hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl Substituted or unsubstituted cycloalkynyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted arylalkenyl, substituted or unsubstituted heteroaryl, substituted Or unsubstituted heteroarylalkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkoxy, substituted or unsubstituted heterocycloalkoxy, substituted or unsubstituted aryloxy, substituted or unsubstituted arylalkyloxy, A monovalent group selected from the group consisting of substituted or unsubstituted arylalkenyloxy, substituted or unsubstituted heteroaryloxy, substituted or unsubstituted heteroarylalkyloxy, and substituted or unsubstituted acyl.

  n is preferably an integer of 1 to 5, more preferably an integer of 1 to 2, and even more preferably 1.

  m is preferably an integer of 0 to 4, more preferably an integer of 0 to 2, and still more preferably 0.

R ³¹ and R ³² are independently of each other halogen, cyano, nitro, substituted or unsubstituted C ₁ -C ₅ alkyl, substituted or unsubstituted C ₂ -C ₅ alkenyl, substituted or unsubstituted C _2- C ₅ alkynyl, substituted or unsubstituted C ₁ -C ₅ alkoxy, substituted or unsubstituted C ₁ -C ₅ acyl, or is preferably -NR ^N31 R ^N32, halogen, nitro, substituted or unsubstituted alkyl More preferably a substituted or unsubstituted alkenyl, a substituted or unsubstituted C _{1 to} C ₅ alkynyl, or —NR ^N31 R ^N32 , more preferably —NR ^N31 R ^N32 , and —NH ₂ . It is particularly preferred.

R ^N31 and R ^N32 are independently of one another, hydrogen, substituted or unsubstituted C ₁ -C ₅ alkyl, substituted or unsubstituted C ₂ -C ₅ alkenyl, substituted or unsubstituted C ₂ -C ₅ alkynyl, And a monovalent group selected from the group consisting of substituted or unsubstituted C _{1 to} C ₅ alkoxy, and more preferably hydrogen.

In formula (A) and formula (IV),
R ⁴¹ , R ⁴² , R ⁴³ and R ⁴⁴ are independently of each other hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted cycloalkyl, substituted Or unsubstituted cycloalkenyl, substituted or unsubstituted cycloalkynyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted arylalkenyl, substituted or unsubstituted Is substituted heteroaryl, or substituted or unsubstituted heteroarylalkyl, or
R ⁴¹ and R ⁴³ together form a substituted or unsubstituted alkylene, substituted or unsubstituted alkenylene, or substituted or unsubstituted alkynylene,
R ⁴⁵ is substituted or unsubstituted alkylene, substituted or unsubstituted alkenylene, or substituted or unsubstituted alkynylene,
R ⁴⁶ is substituted or unsubstituted alkylene, substituted or unsubstituted alkenylene, or substituted or unsubstituted alkynylene,
R ⁴⁷ is substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted arylalkenyl, substituted or Unsubstituted heteroaryl, substituted or unsubstituted heteroarylalkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkoxy, substituted or unsubstituted heterocycloalkoxy, substituted or unsubstituted aryloxy, substituted or non-substituted Substituted arylalkyloxy, substituted or unsubstituted arylalkenyloxy, substituted or unsubstituted heteroaryloxy, substituted or unsubstituted heteroarylalkyloxy, —SH, —S—SH, —COOH, —COR ⁴⁸ , — CH ₂ -COR ⁴⁸ , -COOR ⁴⁸ , -NR ^N41 R ^N42 or —CONR ^N41 R ^N42 provided that the group is 1 to 3 divalent heteroatoms selected from ^═N— , —O—, ^—S— , —SS— and —CO—. Or it may be bonded to R ⁴⁶ via a heteroatom group,
R ⁴⁸ is substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl, substituted or unsubstituted cycloalkynyl, substituted Or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted arylalkenyl, substituted or unsubstituted heteroaryl, substituted or unsubstituted heteroarylalkyl, substituted or Unsubstituted alkoxy, substituted or unsubstituted cycloalkoxy, substituted or unsubstituted heterocycloalkoxy, substituted or unsubstituted aryloxy, substituted or unsubstituted arylalkyloxy, substituted or unsubstituted aryl Lucenyloxy, substituted or unsubstituted heteroaryloxy, substituted or unsubstituted heteroarylalkyloxy, or substituted or unsubstituted acyl,
R ^N41 and R ^N42 are independently of each other hydrogen, hydroxyl, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted Cycloalkenyl, substituted or unsubstituted cycloalkynyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted arylalkenyl, substituted or unsubstituted heteroaryl Substituted or unsubstituted heteroarylalkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkoxy, substituted or unsubstituted heterocycloalkoxy, substituted or unsubstituted aryloxy, substituted or unsubstituted aryla A monovalent group selected from the group consisting of alkyloxy, substituted or unsubstituted arylalkenyloxy, substituted or unsubstituted heteroaryloxy, substituted or unsubstituted heteroarylalkyloxy, and substituted or unsubstituted acyl.

R ⁴¹ , R ⁴² , R ⁴³ and R ⁴⁴ are independently of one another hydrogen, substituted or unsubstituted C ₁ -C ₅ alkyl, substituted or unsubstituted C ₂ -C ₅ alkenyl, substituted or unsubstituted C ₂ -C ₅ alkynyl, substituted or unsubstituted C ₆ -C ₁₅ aryl, substituted or unsubstituted C ₇ -C ₁₆ arylalkyl, substituted or unsubstituted C ₈ -C ₁₇ arylalkenyl, substituted or unsubstituted 5 Preferably it is ˜15 membered heteroaryl, or substituted or unsubstituted 5-15 membered heteroarylalkyl, hydrogen, substituted or unsubstituted C ₁ -C ₅ alkyl, substituted or unsubstituted C ₂ -C ₅ alkenyl, substituted or unsubstituted C ₂ -C ₅ alkynyl, substituted or unsubstituted C ₆ -C ₁₅ aryl, substituted or unsubstituted C ₇ -C ₁₆ arylalkyl, or a substituted or unsubstituted C ₈ -C ₁₇ arylalkenyl der More preferably, hydrogen, and more preferably a methyl, or benzyl.

When R ⁴¹ and R ⁴³ are taken together to form a substituted or unsubstituted alkylene, substituted or unsubstituted alkenylene, or substituted or unsubstituted alkynylene, the group is substituted or unsubstituted C ₁ -C ₁₂ alkylene, substituted or unsubstituted C ₂ -C ₁₂ alkenylene, or preferably a substituted or unsubstituted C ₂ -C ₁₂ alkynylene, be a substituted or unsubstituted C ₂ -C ₁₂ alkylene More preferred is substituted or unsubstituted C ₉ -C ₁₂ alkylene, and particularly preferred is undecadiyl.

R ⁴⁵ is preferably a substituted or unsubstituted C ₁ -C ₅ alkylene, more preferably propylene.

R ⁴⁶ is preferably substituted or unsubstituted C ₁ -C ₇ alkylene, more preferably pentylene, hexylene or heptylene, and even more preferably pentylene.

R ⁴⁷ is substituted or unsubstituted C ₁ -C ₅ alkyl, substituted or unsubstituted C ₂ -C ₅ alkenyl, substituted or unsubstituted C ₂ -C ₅ alkynyl, substituted or unsubstituted C ₇ -C ₁₆ arylalkyl, substituted or unsubstituted 5-15 membered heteroaryl, substituted or unsubstituted 5-15 membered heteroarylalkyl, substituted or unsubstituted C ₁ -C ₅ alkoxy, -SH, -S-SH, _{^{-COOH, -COR 48, -CH 2 -COR}} 48, -COOR 48, is preferably -NR ^N41 R ^N42 or -CONR ^N41 R ^N42, a substituted or unsubstituted C ₁ -C ₅ alkyl, substituted or unsubstituted C ₇ -C ₁₆ arylalkyl substituted, substituted or unsubstituted 5-15 membered heteroarylalkyl, substituted or unsubstituted C ₁ -C ₅ alkoxy, -SH, -S-SH, -COOH , -COR 48 -CH ₂ -COR ⁴⁸ , -COOR ⁴⁸ , -NR ^N41 R ^N42 or -CONR ^N41 R ^N42 is more preferable. Provided that the group is divalent through 1 to 3 divalent heteroatoms or heteroatomic groups selected from = N-, -O-, -S-, -SS- and -CO-. It may be bonded to the spacer part S. More preferably, R ⁴⁷ is —CO—CH ₂ OCH ₃ , —S—CH ₂ —CO—CH ₃ , —CONH—OH, or —SS— (pyridin-2-yl).

R ⁴⁸ is substituted or unsubstituted C ₁ -C ₅ alkyl, substituted or unsubstituted C ₂ -C ₅ alkenyl, substituted or unsubstituted C ₂ -C ₅ alkynyl, or substituted or unsubstituted C ₁ -C It is preferably ₅ alkoxy, more preferably substituted or unsubstituted C ₁ -C ₅ alkyl, and even more preferably methyl or methoxymethyl.

R ^N41 and R ^N42 are independently of one another, hydrogen, hydroxyl, a substituted or unsubstituted C ₁ -C ₅ alkyl, substituted or unsubstituted C ₂ -C ₅ alkenyl, substituted or unsubstituted C ₂ -C ₅ alkynyl is preferably a monovalent group selected from the group consisting of substituted or unsubstituted C ₁ -C ₅ alkoxy, and substituted or unsubstituted C ₁ -C ₅ acyl, hydrogen, hydroxyl, substituted or unsubstituted C ₁ -C ₅ alkyl, and more preferably a monovalent group selected from the group consisting of substituted or unsubstituted C ₁ -C ₅ alkoxy, R ^N41 is hydrogen, and R ^N42 is a hydroxyl More preferably it is.

In formula (A) and formula (V),
R ⁵¹ is substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, —NR ^N51 R ^N52 , —COOH, —COR ⁵³ , or —CONR ^N53 R ^N54 ,
R ⁵² is an acid halide, cyanoformyl, carboxyl, substituted or unsubstituted alkylcarbonyl, substituted or unsubstituted alkenylcarbonyl, substituted or unsubstituted alkynylcarbonyl, substituted or unsubstituted alkoxycarbonyl, substituted or unsubstituted Cycloalkoxycarbonyl, or -CO-NR ^N55 R ^N56 ,
R ^N51 , R ^N52 , R ^N53 , R ^N54 , R ^N55 and R ^N56 are each independently hydrogen, hydroxyl, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted Or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl, substituted or unsubstituted cycloalkynyl, substituted or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted Substituted arylalkenyl, substituted or unsubstituted heteroaryl, substituted or unsubstituted heteroarylalkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted cycloalkoxy, substituted or unsubstituted heterocycloalkoxy, substituted or unsubstituted Aryloxy, substituted young Or unsubstituted arylalkyloxy, substituted or unsubstituted arylalkenyloxy, substituted or unsubstituted heteroaryloxy, substituted or unsubstituted heteroarylalkyloxy, substituted or unsubstituted acyl, and substituted or unsubstituted A monovalent group selected from the group consisting of glycosyloxy,
R ⁵³ is substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl, substituted or unsubstituted cycloalkynyl, substituted Or unsubstituted heterocycloalkyl, substituted or unsubstituted aryl, substituted or unsubstituted arylalkyl, substituted or unsubstituted arylalkenyl, substituted or unsubstituted heteroaryl, substituted or unsubstituted heteroarylalkyl, substituted or Unsubstituted alkoxy, substituted or unsubstituted cycloalkoxy, substituted or unsubstituted heterocycloalkoxy, substituted or unsubstituted aryloxy, substituted or unsubstituted arylalkyloxy, substituted or unsubstituted aryl Lucenyloxy, substituted or unsubstituted heteroaryloxy, substituted or unsubstituted heteroarylalkyloxy, or substituted or unsubstituted acyl.

R ⁵¹ is preferably —NR ^N51 R ^N52 , —COOH, —COR ⁵³ , or —CONR ^N53 R ^N54 , more preferably —NR ^N51 R ^N52 , and —N (CH ₃ ) ₂ . More preferably.

R ⁵² is preferably an acid halide, cyanoformyl, carboxyl, or —CO—NR ^N55 R ^N56 , more preferably —CO—NR ^N55 R ^N56 , —CO—NH—OH, —CO More preferred is —NH (CH ₃ ) or —CO—NH— (D-glucopyranosyloxy), and particularly preferred is —CO—NH—OH.

R ^N51 , R ^N52 , R ^N53 , R ^N54 , R ^N55 and R ^N56 are each independently hydrogen, hydroxyl, substituted or unsubstituted C ₁ -C ₅ alkyl, substituted or unsubstituted C ₂ -C ₅ alkenyl, substituted or unsubstituted C ₂ -C ₅ alkynyl, substituted or unsubstituted C ₃ -C ₆ cycloalkyl, substituted or unsubstituted C ₃ -C ₆ cycloalkenyl, substituted or unsubstituted C ₃ -C ₆ cycloalkynyl, substituted or unsubstituted 5-15 membered heterocycloalkyl, substituted or unsubstituted C ₆ -C ₁₅ aryl, substituted or unsubstituted C ₇ -C ₁₆ arylalkyl, substituted or unsubstituted C ₈ ~ C ₁₇ arylalkenyl, substituted or unsubstituted 5-15 membered heteroaryl, substituted or unsubstituted 5-15 membered heteroarylalkyl, substituted or unsubstituted C ₁ -C ₅ alkoxy, substituted or unsubstituted C _{3 ~C 6} Sik Alkoxy, heterocycloalkoxy 5-15 membered substituted or unsubstituted, substituted or unsubstituted C ₆ -C ₁₅ aryloxy, substituted or unsubstituted C ₇ -C ₁₆ arylalkyloxy, substituted or unsubstituted C ₈ -C ₁₇ aryl alkenyloxy, substituted or unsubstituted 5-15 membered heteroaryloxy, substituted or unsubstituted 5-15 membered heteroaryl alkyloxy, substituted or unsubstituted C ₁ -C ₅ acyl, and substituted or preferably a monovalent group selected from the group consisting of unsubstituted glucopyranosyloxy, hydrogen, hydroxyl, a substituted or unsubstituted C ₁ -C ₅ alkyl, substituted or unsubstituted C ₂ -C ₅ alkenyl, monovalent der selected from the group consisting of substituted or unsubstituted C ₂ -C ₅ alkynyl, and substituted or unsubstituted glucopyranosyloxy More preferably, hydrogen, hydroxyl, more preferably monovalent group selected from the group consisting of substituted or unsubstituted C ₁ -C ₅ alkyl, and substituted or unsubstituted glucopyranosyloxy hydrogen Particularly preferred is hydroxyl or methyl.

R ⁵³ is substituted or unsubstituted C ₁ -C ₅ alkyl, substituted or unsubstituted C ₂ -C ₅ alkenyl, substituted or unsubstituted C ₂ -C ₅ alkynyl, or substituted or unsubstituted C ₁ -C It is preferably ₅ alkoxy, more preferably substituted or unsubstituted C ₁ -C ₅ alkyl, and even more preferably methyl.

In the formula (A) and the formulas (I) to (V), when the group is substituted, the substituent is independently halogen (fluorine, chlorine, bromine or iodine), cyano, nitro, hydroxyl , Sulfanyl, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkenyl, substituted or unsubstituted cycloalkynyl, substituted or It is preferably a monovalent group selected from the group consisting of unsubstituted amino, substituted or unsubstituted alkoxy, and substituted or unsubstituted acyl, halogen (fluorine, chlorine, bromine or iodine), cyano, nitro, hydroxyl, sulfanyl, substituted or unsubstituted C ₁ -C ₅ alkyl, substituted or unsubstituted C ₂ -C ₅ alkenyl, substituted or unsubstituted C ₂ -C ₅ alkynyl, substituted or unsubstituted C ₃ -C ₆ cycloalkyl, substituted or unsubstituted C ₃ -C ₆ cycloalkenyl, substituted or unsubstituted C ₃ -C ₆ cycloalkenyl, substituted or unsubstituted amino, a monovalent group selected from the group consisting of substituted or unsubstituted C ₁ -C ₅ alkoxy, and substituted or unsubstituted C ₁ -C ₅ acyl More preferably. When the group is a substituted alkyl having 2 or more carbon atoms, the substituted alkyl may be in the form of a substituted alkyl having an oxiranyl group.

で表される化合物；
（b）式（II-1）：

で表される化合物；
（c）式（III-1）：

で表される化合物；
（d）式（IV-1）〜（IV-4）：

で表される化合物；及び
（e）式（V-1）：

で表される化合物；
からなる群より選択される少なくとも1種の化合物若しくはその塩、又はそれらの溶媒和物；並びに
（f）酪酸ナトリウム又はその溶媒和物；
からなる群より選択される少なくとも1種の化合物であることが特に好ましい。前記ヒストンデアセチラーゼ阻害剤化合物を用いることにより、耐塩性のような該植物の環境ストレス耐性を特に向上させることができる。 In the plant environmental stress tolerance improving agent of the present invention, the histone deacetylase inhibitor is:
(A) Formula (I-1):

A compound represented by:
(B) Formula (II-1):

A compound represented by:
(C) Formula (III-1):

A compound represented by:
(D) Formulas (IV-1) to (IV-4):

(E) Formula (V-1):

A compound represented by:
At least one compound selected from the group consisting of: or a salt thereof, or a solvate thereof; and (f) sodium butyrate or a solvate thereof;
Particularly preferred is at least one compound selected from the group consisting of: By using the histone deacetylase inhibitor compound, environmental stress tolerance of the plant such as salt tolerance can be particularly improved.

  In the present invention, the histone deacetylase inhibitor compound includes not only the compound itself but also a salt thereof. Examples of the salt of the histone deacetylase inhibitor compound used in the present invention include, but are not limited to, for example, sodium ion, potassium ion, calcium ion, magnesium ion, or substituted or unsubstituted ammonium ion. Cations such as chloride ion, bromide ion, formate ion, acetate ion, maleate ion, fumarate ion, benzoate ion, ascorbate ion, pamoate ion, succinate ion, bismethylenesalicylate ion, methanesulfonic acid Ion, ethanedisulfonate ion, propionate ion, tartrate ion, salicylate ion, citrate ion, gluconate ion, aspartate ion, stearate ion, palmitate ion, itaconic acid ion, glycolic acid ion , P-aminobenzoic acid ion, glutamic acid ion, benzenesulfonic acid ion, cyclohexylsulfamic acid ion, methanesulfonic acid ion, ethanesulfonic acid ion, isethionic acid ion, benzenesulfonic acid ion, p-toluenesulfonic acid ion, naphthalene sulfone Anions such as acid ions, phosphate ions, nitrate ions, sulfate ions, carbonate ions, bicarbonate ions or perchlorate ions are preferred. When the histone deacetylase inhibitor compound used in the present invention is in the form of the salt, the compound can be used without substantially reducing the effect of improving the environmental stress tolerance of plants.

  In the present invention, the histone deacetylase inhibitor compound includes not only the compound itself but also a solvate of the compound or a salt thereof. Solvents that can form solvates with the compound or salt thereof include, but are not limited to, for example, lower alcohols (eg, 1-6 carbons such as methanol, ethanol or 2-propanol (isopropyl alcohol)). Alcohols with the number of atoms), higher alcohols (for example, alcohols with 7 or more carbon atoms such as 1-heptanol or 1-octanol), organics such as dimethyl sulfoxide (DMSO), acetic acid, ethanolamine or ethyl acetate A solvent or water is preferred. When the histone deacetylase inhibitor compound or a salt thereof used in the present invention is in the form of a solvate with the above-mentioned solvent, the compound does not substantially reduce the effect of improving environmental stress tolerance of plants. Can be used.

  In the present invention, the histone deacetylase inhibitor compound includes not only the compound itself but also a protected form thereof. In the present specification, the “protected form” means a form in which a protective group is introduced into one or more functional groups (for example, a hydroxyl group or a carboxylic acid group). In the present specification, a “protecting group” is a group introduced into a specific functional group in order to prevent an undesirable reaction from progressing, and is quantitatively removed under specific reaction conditions. In other reaction conditions, it means a group that is substantially stable, that is, reaction-inactive. The protecting group capable of forming a protected form of the compound is not limited. For example, in the case of a protecting group for a hydroxyl group, silyl (for example, t-butyldimethylsilyl (TBS), triisopropylsilyl (TIPS) Alternatively, when tert-butyldiphenylsilyl (TBDPS) is a protecting group for a carboxylic acid group, an alkyl ester (for example, methyl, ethyl or isopropyl ester) or an arylalkyl ester (for example, benzyl ester) is preferred. The protection and deprotection by the protecting group can be carried out based on known reaction conditions. When the histone deacetylase inhibitor compound used in the present invention is a protected form by the above protecting group, the compound can be used without substantially reducing the effect of improving the environmental stress tolerance of plants. .

  In addition, when the histone deacetylase inhibitor compound used in the present invention has one or more stereocenters (chiral centers), the compound may be an individual enantiomer or diastereomer of the compound, as well as a racemate. And mixtures thereof.

  By having the said characteristic, the histone deacetylase inhibitor compound used in this invention can express the improvement effect of the environmental stress tolerance of a plant.

<2. Agricultural use of environmental stress tolerance improvers>
In this invention, the environmental stress tolerance of the plant can be improved by applying the environmental stress tolerance improving agent of the plant containing the histone deacetylase inhibitor described above as an active ingredient to the plant. Therefore, the present invention relates to an agrochemical preparation or an agricultural chemical containing a histone deacetylase inhibitor as an active ingredient. In one embodiment, the present invention relates to an agrochemical formulation or an agrochemical containing the environmental stress tolerance improver of the present invention as an active ingredient. The present invention also includes applying an agriculturally effective amount of the above-described histone deacetylase inhibitor to the plant or to the soil, medium or culture from which the plant grows. It relates to a method for improving tolerance. In one embodiment, the present invention comprises applying an agriculturally effective amount of the environmental stress tolerance improver of the present invention to a plant or soil, medium or culture medium from which the plant grows. The present invention relates to a method for improving environmental stress tolerance.

  The agrochemical formulations and methods of the present invention can be used to improve the environmental stress tolerance of plants. The environmental stress is preferably salt stress, drought stress, or low temperature stress, and more preferably salt stress. By applying an agrochemical preparation containing the environmental stress tolerance improver of the present invention, for example, the histone deacetylase inhibitor described above as an active ingredient, to the plant, the environmental stress tolerance of the plant such as salt tolerance is improved. Can be made.

  In addition, although the environmental stress tolerance of a plant is not limited, it can be evaluated by the following means. For example, salt stress tolerance can be achieved when a target plant is grown in a medium or soil supplemented with salt at an appropriate concentration in a growth temperature and growth period suitable for the plant (for example, in the case of Arabidopsis, the temperature is 22 ° C., It may be determined by growing under conditions of 2 to 3 weeks) and evaluating the phenotype. Drought stress tolerance means that the target plant grows under conditions of growth temperature, growth humidity and growth period (for example, in the case of Arabidopsis thaliana, temperature 22 ° C., humidity 50% or less, 2 to 3 weeks). And evaluating it by evaluating its phenotype. The freezing stress tolerance is that the target plant is acclimated at a low temperature that does not freeze, and then subjected to a freezing treatment under a temperature condition of −2 ° C. or lower, and then a growth temperature in a state suitable for the plant and What is necessary is just to determine by growing on the conditions of a growth period (For example, in the case of Arabidopsis thaliana, temperature 22 degreeC, 1-2 weeks), and evaluating the phenotype.

  In the agrochemical preparation of the present invention, one or more environmental stress tolerance improvers of the present invention, for example, the histone deacetylase inhibitor described above may be used alone, and one or more agriculturally acceptable You may use it in combination with an ingredient. The agrochemical formulation of the present invention can be formulated into various dosage forms commonly used in the art depending on the desired application method. Therefore, the agrochemical formulation of the present invention also includes an agrochemical containing the environmental stress tolerance improver of the present invention, such as the histone deacetylase inhibitor described above, and one or more agriculturally acceptable components. It can also be provided in the form of a composition. Agriculturally acceptable components used in the agrochemical composition of the present invention include carriers, excipients, binders, solubilizers, stabilizers, thickeners, swelling agents, lubricants, surfactants, An oily liquid, a buffering agent, a disinfectant, an antifreeze agent, an antifoaming agent, a colorant, an antioxidant, and a further active ingredient can be exemplified. Agriculturally acceptable carriers include water, mineral oil fractions such as kerosene or diesel oil, oils derived from plants or animals, cyclic or aromatic hydrocarbons (eg paraffin, tetrahydronaphthalene, alkylated naphthalenes or derivatives thereof) Or alkylated benzenes or their derivatives), alcohols (eg methanol, ethanol, propanol, butanol or cyclohexanol), ketones (eg cyclohexanone), amines (eg N-methylpyrrolidone), or mixtures thereof A top acceptable liquid carrier is preferred.

  When the agrochemical composition of the present invention contains one or more additional active ingredients, examples of the additional active ingredients include compounds having activity for improving environmental stress tolerance known in the art.

  Histone deacetylase is an enzyme widely present in eukaryotes including plants. Therefore, the plant which is the target of the environmental stress tolerance improving agent or agrochemical preparation of the plant of the present invention containing the histone deacetylase inhibitor of the present invention as an active ingredient is not particularly limited. It can be applied to seed plants including angiosperms and gymnosperms. Specific examples of the plant to which the present invention is applied include, but are not limited to, for example, cruciferous plants such as Arabidopsis thaliana and rape, legumes such as soybean, rice, corn, wheat and barley. Various gramineous plants, convolvulaceae plants such as morning glory, willow plants such as poplar, euphorbiaceae plants such as capsicum, cassava and jatropha, vine plants such as grapes, and eggplants such as tomatoes Can be mentioned. The plant may be not only the plant itself but also a part of the plant such as tissue, organ (for example, vegetative propagation organ such as rhizome, tuberous root, corm or runner), cultured cell and / or callus. By applying the plant environmental stress tolerance improver or agrochemical preparation of the present invention to the plant as described above, the plant's environmental stress tolerance can be improved.

  The plant environmental stress tolerance improving agent or agrochemical preparation of the present invention may be applied to the plant or any part thereof (for example, seed, seedling or mature plant) in any growth stage before germination or after germination. it can. Moreover, the environmental stress tolerance improving agent or agrochemical preparation of the plant of the present invention can be applied not only to the plant itself but also to the soil, medium or culture solution from which the plant grows. By applying the environmental stress tolerance improving agent or agrochemical preparation of the plant of the present invention to the plant in the growth stage as described above or the soil, medium or culture solution from which the plant grows, the environmental stress tolerance of the plant Can be improved.

  The method of the present invention optionally comprises a plant or soil from which the plant grows in addition to one or more environmental stress tolerance improvers of the present invention, such as the histone deacetylase inhibitor described above. And may further include applying to a culture medium or culture medium. The further agent is preferably a further active ingredient of the agrochemical composition described above. In this case, the order in which the environmental stress tolerance improver of the present invention, for example, the histone deacetylase inhibitor described above, and the additional agent are applied to the plant or the soil, medium or culture solution from which the plant grows is as follows: There is no particular limitation. For example, the environmental stress tolerance improving agent of the present invention, for example, the histone deacetylase inhibitor described above and the additional agent at the same time (as a single or separate preparation), or the soil or medium from which the plant grows Or you may apply to a culture solution or may apply sequentially. In addition to the environmental stress tolerance improving agent of the present invention, for example, the histone deacetylase inhibitor described above, the environmental stress tolerance of the plant can be more remarkably improved by applying a further agent to the plant or the like. .

  The dosage form of the agrochemical preparation of the present invention is not particularly limited. It can be formulated into dosage forms such as emulsions, wettable powders, liquids, aqueous solvents, powders, powders, pastes or granules, which are usually used in the art. The content of the environmental stress tolerance improver of the present invention in the agrochemical preparation of the present invention, for example, the histone deacetylase inhibitor described above is, for example, in the range of 0.01 to 100 mg per liter of the applied volume, Usually, it is in the range of 0.3 to 75 mg per liter of volume at the time of application, and typically in the range of 0.3 to 3 mg per liter of volume at the time of application.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the technical scope of the present invention is not limited to these examples.

<I: Preparation of compound>
The test compounds used in the following tests were provided by Dr. Kaoru Yoshida, RIKEN.

<II: salt tolerance improvement test using Arabidopsis>
Arabidopsis seeds were sterilized. In each well of a sterilized 24-well microplate, add 1 ml of 1/2 MS liquid medium (2.15 g / L MS powder, 1 wt% sucrose, 1/1000 B5 vitamin, 0.5 g / L MES, And 0.1% by mass agar, adjusted to pH 5.7 with 1N KOH). Three sterilized Arabidopsis seeds per well were seeded so as to float on the 1/2 MS liquid medium in the well. The seeded microplate was subjected to low temperature treatment at 4 ° C. in the dark for 2 days. Thereafter, the microplate was moved into an incubator set at 22 ° C., and Arabidopsis thaliana was grown at 22 ° C. for 3 days. A predetermined amount of a test compound was added to a predetermined well, and Arabidopsis thaliana was further grown at 22 ° C. for 24 hours. Thereafter, 100 mM NaCl was added to the predetermined well, and Arabidopsis thaliana was grown at 22 ° C. for 3 days. The phenotype of the grown Arabidopsis was observed with the naked eye or a stereomicroscope. A plant body in which yellowing or whitening of a cotyledon or a main leaf was observed as compared with an Arabidopsis plant in a NaCl-free group was determined as a plant body affected by salt stress. In each test group, the percentage of the number of plants affected by salt stress relative to the total number of plants (3 × 4 wells = 12 plants) was calculated as the survival rate (%) under salt stress conditions. For the test groups to which the compounds represented by formulas (IV-1), (IV-3) and (IV-4), and sodium butyrate were added, each test was repeated twice, and the average value and standard error were calculated. Calculated.

  The survival rate of Arabidopsis plants when the compounds represented by the formulas (III-1), (I-1), (II-1) and (V-1) were added was determined by the following method. In the same procedure as described above, Arabidopsis seeds were seeded in each well of a 24-well microplate and subjected to low-temperature treatment. Thereafter, the microplate was moved into an incubator set at 22 ° C., and Arabidopsis thaliana was grown at 22 ° C. for 4 days. A predetermined amount of a test compound (compounds represented by (III-1), (I-1), (II-1) and (V-1)) is added to a predetermined well, and the Arabidopsis thaliana is further added at 22 ° C. For 10-24 hours. Thereafter, 120 mM NaCl was added to the predetermined well, and Arabidopsis thaliana was grown at 22 ° C. for 3 days. Thereafter, the phenotype of the grown Arabidopsis thaliana was observed by the same procedure as described above, and the survival rate (%) under salt stress conditions was calculated.

  FIG. 1 shows the survival rate (%) under the salt stress condition when each test compound is added (average value and standard error for the test section where the test was repeated twice). Moreover, the phenotypes of Arabidopsis plants in the NaCl-added medium to which each test compound is added are shown in FIGS. 2A to 2C and FIGS. 3A and 3B, respectively.

  As shown in FIG. 1, when a compound represented by formulas (IV-1) to (IV-4), which are histone deacetylase inhibitors, and sodium butyrate are added to a medium, Arabidopsis plants under salt stress conditions The survival rate was significantly improved. In particular, when the compounds represented by the formulas (IV-1) and (IV-4) and sodium butyrate are added to the culture medium, substantially all Arabidopsis plants are affected by salt stress, so The leaves grew without yellowing or whitening (ie the survival rate was 100%). In addition, using the compounds represented by formulas (III-1), (I-1), (II-1) and (V-1), the survival rate of Arabidopsis plants under salt stress conditions by the above procedure As a result, the survival rate was 100% when any compound was added.

  As shown in FIG. 2A, the compounds represented by formulas (III-1) and (I-1) partially whiten or yellowed cotyledons or true leaves due to salt stress at concentrations of 50 μM or 0.1 μM, respectively. And suppressed whitening or yellowing of cotyledons or true leaves due to salt stress almost completely at a concentration of 200 μM or 1 μM, respectively. As shown in FIG. 2B, the compound represented by formula (II-1) partially inhibits whitening or yellowing of cotyledons or true leaves due to salt stress at a concentration of 0.1 μM, and at a concentration of 1 μM. The whitening or yellowing of cotyledons or true leaves caused by salt stress was almost completely suppressed. As shown in FIG. 2C, the compound represented by the formula (V-1) partially inhibits whitening or yellowing of cotyledons or true leaves due to salt stress at a concentration of 0.1 μM, and at a concentration of 1.0 μM. The whitening or yellowing of cotyledons or true leaves caused by salt stress was almost completely suppressed. In addition, when no NaCl was added, the Arabidopsis plant in the treatment group to which the compound represented by the formula (V-1) was added at any concentration was used for the control group (that is, the compound represented by the formula (V-1)). It showed a normal phenotype substantially identical to the plant in the non-added group. Therefore, it is presumed that the compound represented by the formula (V-1) did not affect the growth itself of Arabidopsis but specifically improved the salt tolerance of Arabidopsis.

  As shown in FIGS. 3A and 3B, the compounds represented by the formulas (IV-1) to (IV-4) are 1 μM in concentration, and sodium butyrate is 1 mM in concentrations of cotyledons or The whitening or yellowing of the true leaves was almost completely suppressed. In addition, when no NaCl was added, the Arabidopsis plants in the treatment group to which the test compound was added exhibited a normal phenotype that was substantially the same as the plants in the control group (that is, the group to which no test compound was added). Therefore, it is speculated that the compounds represented by the formulas (IV-1) to (IV-4) and sodium butyrate did not affect the growth of Arabidopsis itself, but specifically improved the salt tolerance of Arabidopsis. Is done.

  In the same procedure as described above, Arabidopsis seeds were seeded in each well of a 24-well microplate and subjected to low-temperature treatment. Thereafter, the microplate was moved into an incubator set at 22 ° C., and Arabidopsis thaliana was grown at 22 ° C. for 4 days. 150 μM of the test compound (compound represented by (III-1)) was added to a predetermined well, and Arabidopsis was further grown at 22 ° C. for 10 to 24 hours. The control group was a group to which no test compound was added. Thereafter, 120 mM NaCl was added to all wells, and Arabidopsis thaliana was grown at 22 ° C. for 3 days. Thereafter, the phenotype of the grown Arabidopsis was observed in the same procedure as described above. FIG. 4 shows the phenotype of the Arabidopsis plant in the NaCl-added medium to which the compound represented by the formula (III-1) is added.

  As shown in FIG. 4, the compound represented by the formula (III-1) almost completely suppressed whitening or yellowing of cotyledons or true leaves due to salt stress at a concentration of 150 μM.

Table 1 shows the lowest effective concentration of each test compound in the salt tolerance improvement test using the Arabidopsis thaliana.

Claims (4)

Hereinafter:
(A) Formula (I-1):

A compound represented by:
(B) Formula (II-1):

A compound represented by:
(C) Formula (III-1):

A compound represented by:
(D) Formulas (IV-1) to (IV-4):

(E) Formula (V-1):

A compound represented by:
At least one compound selected from the group consisting of: or a salt thereof, or a solvate thereof; and (f) sodium butyrate or a solvate thereof;
Is at least one compound selected from the group consisting of containing a histone deacetylase inhibitor as an active ingredient, salt tolerance improver of plants. An agrochemical preparation for improving the salt tolerance of a plant, comprising the plant salt tolerance improving agent according to claim 1 as an active ingredient. An agrochemical composition for improving the salt tolerance of a plant, comprising the plant salt tolerance improving agent according to claim 1 and one or more kinds of agriculturally acceptable components. Applying an agriculturally effective amount of the salt tolerance improving agent of the plant according to claim 1 to the plant or the soil, culture medium or culture solution from which the plant grows, to improve the salt tolerance of the plant Method.

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