Ginseng (Panax ginseng), a valued medicinal herb, is a slow-growing plant that flowers after 3 ye... more Ginseng (Panax ginseng), a valued medicinal herb, is a slow-growing plant that flowers after 3 years of growth with the formation of a solitary terminal umbel inflorescence. However, little is known about cytological events during ginseng reproduction, such as the development of the male organ, the stamen. To better understand the mechanism controlling ginseng male reproductive development, here, we investigated the inflorescence and flower structure of ginseng. Moreover, we performed cytological analysis of anther morphogenesis and showed the common and specialized cytological events including the formation of four concentric cell layers surrounding male reproductive cells followed by subsequent cell differentiation and degeneration of tapetal cells, as well as the formation of mature pollen grains via meiosis and mitosis during ginseng anther development. Particularly, our transverse section and microscopic observations showed that the ginseng tapetal layer exhibits obvious nonsynchronous cell division evidenced by the observation of one or two tapetal layers frequently observed in one anther lobe, suggesting the unique control of cell division. To facilitate the future study on ginseng male reproduction, we grouped the anther development into 10 developmental stages according to the characterized cytological events.
Glycosyltransferases aremembers of themultigene family of plants that can transfer single ormulti... more Glycosyltransferases aremembers of themultigene family of plants that can transfer single ormultiple activated sugars to a range of plantmolecules, resulting in the glycosylation of plant compounds. Although the activities of many glycosyltransferases and their products have been recognized for a long time, only in recent years were some glycosyltransferase genes identified and fewhave been functionally characterized in detail. Korean ginseng (Panax ginseng Meyer), belonging to Araliaceae, has been well known as a popularmysteriousmedicinal herb in East Asia for over 2000 years. A total of 704 glycosyltransferase unique sequences have been found from a ginseng expressed sequence tag (EST) library, and these sequences encode enzymes responsible for the secondary metabolite biosynthesis. Finally, twelve UDP glycosyltransferases (UGTs) were selected as the candidates most likely to be involved in triterpenoid synthesis. In this study, we classified the candidate P. ginseng UGTs (PgUGTs) into proper families and groups, which resulted in eight UGT families and six UGT groups. We also investigated those gene candidates encoding for glycosyltransferases by analysis of gene expression in methyl jasmonate (MeJA)-treated ginseng adventitious roots and different tissues from four-year-old ginseng using quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). For organ-specific expression, most of PgUGT transcription levelswere higher in leaves and roots comparedwith flower buds and stems. The transcription of PgUGTs in adventitious roots treated with MeJA increased as compared with the control. PgUGT1 and PgUGT2, which belong to the UGT71 family genes expressed in MeJA-treated adventitious roots, were especially sensitive, showing 33.32 and 38.88-fold expression increases upon 24 h post-treatments, respectively.
Geranylgeranyl-diphosphate synthases (GGDPS) catalyze branch point enzymatic reactions producing ... more Geranylgeranyl-diphosphate synthases (GGDPS) catalyze branch point enzymatic reactions producing isoprenoid-derived products which are necessary for plant growth and responses to a wide range of biotic and abiotic stresses. In our study, full length geranylgeranyl-diphosphate synthase 1 (PgGGDPS1) and 2 (PgGGDPS2) cDNA were isolated and characterized from the flower of Panax ginseng and 4-year old P. ginseng cv. Gumpoong. The cDNA had open reading frame of 1032 and 1116 bp with a deduced amino acid sequence of 343 and 371 residues for GGDPS1 and GGDPS2, respectively. The calculated molecular mass of GGDPS1 and GGDPS2 were approximately 37.66 and 40.21 kDa with a predi-cated isoelectric point of 5.32 and 6.23 and predicted localization of plastid. A GenBank Blast X search revealed that the deduced amino acid of PgGGDPS1 shared a high degree of homology with GGDPS from Panax notoginseng. The transcription pattern of GGDPS genes was different at various developmental stages. Both GGDPS genes were highly expressed in aerial parts of the plant, especially in rapidly growing tissues such as 4-year old flower and stem tissues. Transcript level of PgGGDPS1 was differentially induced in ginseng not only during Pseudomonas syringae pv tomato infection but also after exposure to abiotic stresses. Our results suggested that the induction of GGDPS genes specifically PgGGDPS1 by drought stress may affect chlorophyll levels, intracellular GA content and accumulation of carotenoids as the precursor for higher production of ABA and possibly stomatal closure as the barrier for water loss.
Two novel Gram-staining-positive bacteria, designated DCY60T and DCY90T, were isolated from soil ... more Two novel Gram-staining-positive bacteria, designated DCY60T and DCY90T, were isolated from soil of a ginseng field in the Republic of Korea. 16S rRNA gene sequence comparisons showed the two novel strains were closely related to members of the genus Humibacter with greatest similarity to Humibacter antri KCTC 33009T (98.8 and 98.4 % for DCY60T and DCY90T, respectively). The predominant menaquinones present were MK-11 and MK-12. The major fatty acids were anteiso-C17 : 0 and summed feature 8 containing C18 : 1ω7c and/or C18 : 1ω6c. The DNA G+C contents of strains DCY60T and DCY90T were 62.8 and 66.8 mol%, respectively. The peptidoglycan of both strains contained the amino acids ornithine, 2,4-diaminobutyric acid, alanine, glutamic acid and glycine. The cell-wall sugars of strain DCY60T comprised glucose, galactose, rhamnose and xylose, while strain DCY90T contained glucose, galactose, rhamnose and ribose. The major polar lipids of both strains were phosphatidylglycerol, an unidentified glycolipid, and an unknown phospholipid. On the basis of the phenotypic analysis strains DCY60T and DCY90T represent novel species of the genus Humibacter, for which names Humibacter ginsengiterrae sp. nov. (type strain DCY60T = KCTC 33520T = JCM 30079T) and Humibacter ginsengisoli sp. nov. (type strain DCY90T = KCTC 33521T = JCM 30080T) are proposed.
Ginseng (Panax ginseng), a valued medicinal herb,
is a slow-growing plant that flowers after 3 ye... more Ginseng (Panax ginseng), a valued medicinal herb, is a slow-growing plant that flowers after 3 years of growth with the formation of a solitary terminal umbel inflorescence. However, little is known about cytological events during ginseng reproduction, such as the development of the male organ, the stamen. To better understand the mechanism controlling ginseng male reproductive development, here, we investigated the inflorescence and flower structure of ginseng. Moreover, we performed cytological analysis of anther morphogenesis and showed the common and specialized cytological events including the formation of four concentric cell layers surrounding male reproductive cells followed by subsequent cell differentiation and degeneration of tapetal cells, as well as the formation of mature pollen grains via meiosis and mitosis during ginseng anther development. Particularly, our transverse section and microscopic observations showed that the ginseng tapetal layer exhibits obvious nonsynchronous cell division evidenced by the observation of one or two tapetal layers frequently observed in one anther lobe, suggesting the unique control of cell division. To facilitate the future study on ginseng male reproduction, we grouped the anther development into 10 developmental stages according to the characterized cytological events.
Upon mechanical wounding, plants locally induce necrosis, accumulate methyl jasmonate (MeJA) and ... more Upon mechanical wounding, plants locally induce necrosis, accumulate methyl jasmonate (MeJA) and acquire systemic resistance in nearby tissues. One-month-old in vitro grown Panax ginseng seedlings were treated with either 50 µM MeJA or mechanical wounding alone or a combination of both, to evaluate jasmonic acid (JA) signaling and terpene biosynthetic pathway genes along with terpenoid accumulation. After MeJA treatment, JA pathway genes, such as lipoxygenase (PgLOX), hydrogen peroxidase lyase (PgHPL), allene oxide synthase (PgAOS), and allene oxide cyclase (PgAOC1), and terpene pathway genes, such as isopentenyl diphosphate isomerase (PgIPP) and farnesyl diphosphate synthase (PgFPS), were highly expressed and resulted in the accumulation of mono- and sesquiterpenes. During mechanical wounding, PgLOX expression was induced relatively late after 72 h of treatment, however PgAOC1 was not induced. This resulted in decreased production of MeJA that in turn may have lowered terpenoid production. In contrast, wounding + MeJA treatment increased PgAOC1 and PgLOX gene expression earlier after 6 h and slowly promoted the production of mono- and sesquiterpenes. Furthermore, we monitored the effect of MeJA upon wounding in in vitro grown 1-month-old seedlings treated with MeJA + wounding. These result demonstrated that exogenous MeJA is able to promote recovery from the wounding effect by functioning as a long distance signal. Additionally, these results suggest that exogenous MeJA supplied at the time of mechanical wounding prevents necrosis in the ginseng leaves by increasing the production of terpenoids.
Strain DCY91T
, a Gram-stain-negative, rodshaped,
aerobic, non-motile bacterium, was isolated
... more Strain DCY91T
, a Gram-stain-negative, rodshaped,
aerobic, non-motile bacterium, was isolated
from soil of ginseng field in Gyeonggi province, South
Korea. Strain DCY91T shared the highest 16S rRNA
gene sequence similarity with Sphingomonas mucosissima
DSM 17494T (98.55 %), Sphingomonas dokdonensis
KACC 17420T (98.11 %) and Sphingomonas xinjiangensis
DSM 26736T (96.68 %). The strain DCY91T was
found to able to grow best in trypticase soy agar at 28 °C,
at pH 7 and at 0.5 % NaCl. Ubiquinone 10 was identified
as the isoprenoid quinone. The major polar lipids
were identified as sphingoglycolipid, diphosphatidylglycerol,
phosphatidylethanolamine, phosphatidylglycerol
and phosphatidylcholine. The major fatty acids of strain DCY91T were identified as unsaturated C18:1ω7c and saturated
C16:0. The major polyamine content was sym-homospermidine.
The DNA G + C content was determined to
be 65.8 mol% (HPLC). After 6 days of incubation, strain
DCY91T produced 9.64 ± 1.73 and 33.73 ± 4.66 µg/ml
indole-3-acetic acid, using media without l-tryptophan
and supplemented with l-tryptophan, respectively. Strain
DCY91T was also weakly solubilized phosphate and produced
siderophores. On the basis of the phenotypic characteristics,
genotypic analysis and chemotaxonomic characteristics,
strain DCY91T is considered to represent a
novel species of the genus Sphingomonas, for which the
name Sphingomonas panaciterrae sp. nov. is proposed.
The type strain is DCY91T (=KCTC 42346T =JCM
30807T).
Geranylgeranyl-diphosphate synthases (GGDPS) catalyze branch point enzymatic reactions producing ... more Geranylgeranyl-diphosphate synthases (GGDPS) catalyze branch point enzymatic reactions producing isoprenoid-derived products which are necessary for plant growth and responses to a wide range of biotic and abiotic stresses. In our study, full length geranylgeranyl-diphosphate synthase 1 (PgGGDPS1) and 2 (PgGGDPS2) cDNA were isolated and characterized from the flower of Panax ginseng and 4-year old P. ginseng cv. Gumpoong. The cDNA had open reading frame of 1032 and 1116 bp with a deduced amino acid sequence of 343 and 371 residues for GGDPS1 and GGDPS2, respectively. The calculated molecular mass of GGDPS1 and GGDPS2 were approximately 37.66 and 40.21 kDa with a predicated isoelectric point of 5.32 and 6.23 and predicted localization of plastid. A GenBank Blast X search revealed that the deduced amino acid of PgGGDPS1 shared a high degree of homology with GGDPS from Panax notoginseng. The transcription pattern of GGDPS genes was different at various developmental stages. Both GGDPS genes were highly expressed in aerial parts of the plant, especially in rapidly growing tissues such as 4-year old flower and stem tissues. Transcript level of PgGGDPS1 was differentially induced in ginseng not only during Pseudomonas syringae pv tomato infection but also after exposure to abiotic stresses. Our results suggested that the induction of GGDPS genes specifically PgGGDPS1 by drought stress may affect chlorophyll levels, intracellular GA content and accumulation of carotenoids as the precursor for higher production of ABA and possibly stomatal closure as the barrier for water loss.
A novel bacterial strain, DCY86T (=KCTC 42053T = JCM 19890T) was isolated from soil of a ginseng ... more A novel bacterial strain, DCY86T (=KCTC 42053T = JCM 19890T) was isolated from soil of a ginseng field in Yeoncheon province (38°04′00″N 126°57′00″E), Republic of Korea using a serial dilution method. Strain DCY86T was observed to be Gram-stain negative, strictly aerobic, to grow optimally at 25–30 °C, at pH 7–7.5 and on tryptic soya agar medium. The cells were found to be sensitive to ceftazidine and tetracycline. Based on 16S rRNA gene sequence comparisons, strain DCY86T was found to be most closely related to Cupriavidus basilensis LMG 18990T (98.48 %), Cupriavidus numazensis LMG 26411T (98.34 %), Cupriavidus pinatabonesis KCTC 22125T (98.34 %) and Cupriavidus laharis KCTC 22126T (98.00 %). The G+C content was determined to be 64.23 mol %. The only isoprenoid quinone detected in strain DCY86T was ubiquinone Q-8. The major polar lipids were identified as diphosphatidylglycerol, phosphtidylethanolamine, phosphatidylglycerol, unidentified aminophosphoglycolipids and unidentified phospholipids. The major fatty acids were identified as C16:0 summed feature 3 (C16:1 ω7c/ω6c and/or iso-C15 : 0 2-OH) and summed feature 8 (C18:1 ω7c and/or C18:1 ω6c). These data support the affiliation of strain DCY86T to the genus Cupriavidus. Strain DCY86T was also found to be able to solubilize phosphate and produce siderophores. The results of physiological and biochemical tests enabled strain DCY86T to be differentiated genotypically and phenotypically from the recognized species of the genus Cupriaividus. Therefore, the novel isolate can be considered to represent a novel species, for which the name Cupriavidus yeoncheonense sp. nov. is proposed here. The type strain is DCY86T (=KCTC 42053T = JCM 19890T).
Current agricultural production methods, for example the improper use of chemical fertilizers and... more Current agricultural production methods, for example the improper use of chemical fertilizers and pesticides, create many health and environmental problems. Use of plant growth-promoting bacteria (PGPB) for agricultural benefits is increasing worldwide and also appears to be a trend for the future. There is possibility to develop microbial inoculants for use in agricultural biotechnology, based on these beneficial plant–microbe interactions. For this study, ten bacterial strains were isolated from Yongin forest soil for which in vitro plant-growth promoting trait screenings, such as indole acetic acid (IAA) production, a phosphate solubilization test, and a siderophore production test were used to select two PGPB candidates. Arabidopsis thaliana plants were inoculated with Paenibacillus yonginensis DCY84T and Micrococcus yunnanensis PGPB7. Salt stress, drought stress and heavy metal (aluminum) stress challenges indicated that P. yonginensis DCY84T-inoculated plants were more resistant than control plants. AtRSA1, AtVQ9 and AtWRKY8 were used as the salinity responsive genes. The AtERD15, AtRAB18, and AtLT178 were selected to check A. thaliana responses to drought stress. Aluminum stress response was checked using AtAIP, AtALS3 and AtALMT1. The qRT-PCR results indicated that P. yonginensis DCY84T can promote plant tolerance against salt, drought, and aluminum stress. P. yonginensis DCY84T also showed positive results during in vitro compatibility testing and virulence assay against X. oryzae pv. oryzae Philippine race 6 (PXO99). Better germination rates and growth parameters were also recorded for the P. yonginensis DCY84T Chuchung cultivar rice seed which was grown on coastal soil collected from Suncheon. Based on these results, P. yonginensis DCY84T can be used as a promising PGPB isolate for crop improvement.
Strain DCY85T and DCY85-1T, isolated from rhizosphere of ginseng, were rod-shaped, Gram-reaction-... more Strain DCY85T and DCY85-1T, isolated from rhizosphere of ginseng, were rod-shaped, Gram-reaction-negative, strictly aerobic, catalase positive and oxidase negative. 16S rRNA gene sequence analysis revealed that strain DCY85T as well as DCY85-1T belonged to the genus Burkholderia and were closely related to Burkholderia fungorum KACC 12023T (98.1 and 98.0 % similarity, respectively). The major polar lipids of strain DCY85T and DCY85-1T were phosphatidylethanolamine, one unidentified aminolipid and two unidentified phospholipids. The major fatty acids of both strains are C16:0, C18:1 ω7c and summed feature 3 (C16:1 ω6c and/or C16:1 ω7c). The predominant isoprenoid quinone of each strain DCY85T and DCY85-1T was ubiquinone (Q-8) and the G+C content of their genomic DNA was 66.0 and 59.4 mol%, respectively, which fulfill the characteristic range of the genus Burkholderia. The polyamine content of both DCY85T and DCY85-1T was putrescine. Although both DCY85T and DCY85-1T have highly similar 16S rRNA and identical RecA and gyrB sequences, they show differences in phenotypic and chemotaxonomic characteristics. DNA–DNA hybridization results proved the consideration of both strains as two different species. Based on the results from our polyphasic characterization, strain DCY85T and DCY85-1T are considered novel Burkholderia species for which the name Burkholderia ginsengiterrae sp. nov and Burkholderia panaciterrae sp. nov are, respectively, proposed. An emended description of those strains is also proposed. DCY85T and DCY85-1T showed antagonistic activity against the common root rot pathogen of ginseng, Cylindrocarpon destructans. The proposed type strains are DCY85T (KCTC 42054T = JCM 19888T) and DCY85-1T (KCTC 42055T = JCM 19889T).
Strain DCY84T, a Gram-stain positive, rodshaped,
aerobic, spore-forming bacterium, motile by
me... more Strain DCY84T, a Gram-stain positive, rodshaped,
aerobic, spore-forming bacterium, motile by
means of peritrichous flagella, was isolated fromhumus
soil from Yongin forest in Gyeonggi province, South
Korea. Strain DCY84T shared the highest sequence
similarity with Paenibacillus barengoltzii KACC
15270T (96.86 %), followed by Paenibacillus timonensis
KACC 11491T (96.49 %) and Paenibacillus
phoenicis NBRC 106274T (95.77 %). Strain DCY84T
was found to able to grow best in TSA at temperature
30 C, at pH 8 and at 0.5 % NaCl. MK-7 menaquinone
was identified as the isoprenoid quinone. The major
polar lipids were identified as phosphatidylethanolamine,
an unidentified aminophospholipid, two unidentified
aminolipids and an unidentified polar lipid. The
peptidoglycan was found to contain the amino acids
meso-diaminopimelic acid, alanine and D-glutamic
acid. The major fatty acids of strain DCY84T were
identified as branched chain anteiso-C15:0, saturated
C16:0 and branched chain anteiso-C17:0. The cell wall
sugars of strain DCY84T were found to comprise of
ribose, galactose and xylose. The major polyamine was
identified as spermidine. The DNA G?C content was
determined to be 62.6 mol%. After 6 days of incubation,
strain DCY84T produced 52.96 ± 1.85 and
72.83 ± 2.86 lg/ml L-indole-3-acetic acid, using
media without L-tryptophan and supplemented with Ltryptophan,
respectively. Strain DCY84T was also
found to be able to solubilize phosphate and produce
siderophores. On the basis of the phenotypic characteristics,
genotypic analysis and chemotaxonomic characteristics,
strain DCY84T is considered to represent a
novel species of the genus Paenibacillus, for which the
name Paenibacillus yonginensis sp. nov. is proposed.
The type strain is DCY84T (=KCTC 33428T = JCM
19885T).
Ectopic overexpression of the aluminum-induced protein gene
from Panax ginseng enhances heavy met... more Ectopic overexpression of the aluminum-induced protein gene from Panax ginseng enhances heavy metal tolerance in transgenic Arabidopsis
Glutathione peroxidases (GPXs) are a group of enzymes that protect cells against oxidative damage... more Glutathione peroxidases (GPXs) are a group of enzymes that protect cells against oxidative damage generated by reactive oxygen species (ROS). GPX catalyzes the reduction of hydrogen peroxide (H2O2) or organic hydroperoxides to water or alcohols by reduced glutathione. The presence of GPXs in plants has been reported by several groups, but the roles of individual members of this family in a single plant species have not been studied. Two GPX cDNAs were isolated and characterized from the embryogenic callus of Panax ginseng. The two cDNAs had an open reading frame (ORF) of 723 and 681 bp with a deduced amino acid sequence of 240 and 226 residues, respectively. The calculated molecular mass of the matured proteins are approximately 26.4 kDa or 25.7 kDa with a predicated isoelectric point of 9.16 or 6.11, respectively. The two PgGPXs were elevated strongly by salt stress and chilling stress in a ginseng seedling. In addition, the two PgGPXs showed different responses against biotic stress. The positive responses of PgGPX to the environmental stimuli suggested that ginseng GPX may help to protect against environmental stresses.
Glycosyltransferases aremembers of themultigene family of plants that can transfer single ormulti... more Glycosyltransferases aremembers of themultigene family of plants that can transfer single ormultiple activated sugars to a range of plantmolecules, resulting in the glycosylation of plant compounds. Although the activities of many glycosyltransferases and their products have been recognized for a long time, only in recent years were some glycosyltransferase genes identified and fewhave been functionally characterized in detail. Korean ginseng (Panax ginseng Meyer), belonging to Araliaceae, has been well known as a popularmysteriousmedicinal herb in East Asia for over 2000 years. A total of 704 glycosyltransferase unique sequences have been found from a ginseng expressed sequence tag (EST) library, and these sequences encode enzymes responsible for the secondary metabolite biosynthesis. Finally, twelve UDP glycosyltransferases (UGTs) were selected as the candidates most likely to be involved in triterpenoid synthesis. In this study, we classified the candidate P. ginseng UGTs (PgUGTs) into proper families and groups, which resulted in eight UGT families and six UGT groups. We also investigated those gene candidates encoding for glycosyltransferases by analysis of gene expression in methyl jasmonate (MeJA)-treated ginseng adventitious roots and different tissues from four-year-old ginseng using quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). For organ-specific expression, most of PgUGT transcription levelswere higher in leaves and roots comparedwith flower buds and stems. The transcription of PgUGTs in adventitious roots treated with MeJA increased as compared with the control. PgUGT1 and PgUGT2, which belong to the UGT71 family genes expressed in MeJA-treated adventitious roots, were especially sensitive, showing 33.32 and 38.88-fold expression increases upon 24 h post-treatments, respectively.
Pathogenesis-related proteins (PRs) are known
to function in higher plants as a protein-based def... more Pathogenesis-related proteins (PRs) are known to function in higher plants as a protein-based defensive system against abiotic and biotic stress, particularly pathogen infections. A full-length cDNA sequence of PR BetV1 was isolated and characterized from a 14-year-old ginseng expressed sequence tags library and we named this as PgPR10-4, because of similar identities with previous isolated PgPR10s sequences. The PgPR10-4 gene encodes a 477 bp open reading frame and its deduced protein contains 158 amino acids with a 53 % identity with that of the Actinidia chinensis BetV1 allergen. The expression of PgPR10-4 gene was abundant in leaves and its transcripts showed differentially up-regulated patterns against several ginseng pathogens and abiotic stimuli such as high light and salinity. In addition, PgPR10-4 expression was strongly responsive towards the stress signaling molecules H2O2 and jasmonic acid (JA), while weekly responsive to salicylic acid and abscisic acid. A functional role of PgPR10-4 in environmental stress tolerance was further validated through its overexpression in Arabidopsis. An analysis of T2 transgenic Arabidopsis plants overexpressing the PgPR10-4 gene showed an enhanced tolerance to bacterial and fungal infection, but not to salt stress. When we tagged with cyan fluorescent protein fusion protein, the PgPR10-4-was found to localize to the cytoplasm. The enhanced antifungal activity observed from the Arabidopsis transgenic lines suggests the possible involvement of PgPR10-4 in a defense-related mechanism via the JA signaling pathway.
Ginseng (Panax ginseng), a valued medicinal herb, is a slow-growing plant that flowers after 3 ye... more Ginseng (Panax ginseng), a valued medicinal herb, is a slow-growing plant that flowers after 3 years of growth with the formation of a solitary terminal umbel inflorescence. However, little is known about cytological events during ginseng reproduction, such as the development of the male organ, the stamen. To better understand the mechanism controlling ginseng male reproductive development, here, we investigated the inflorescence and flower structure of ginseng. Moreover, we performed cytological analysis of anther morphogenesis and showed the common and specialized cytological events including the formation of four concentric cell layers surrounding male reproductive cells followed by subsequent cell differentiation and degeneration of tapetal cells, as well as the formation of mature pollen grains via meiosis and mitosis during ginseng anther development. Particularly, our transverse section and microscopic observations showed that the ginseng tapetal layer exhibits obvious nonsynchronous cell division evidenced by the observation of one or two tapetal layers frequently observed in one anther lobe, suggesting the unique control of cell division. To facilitate the future study on ginseng male reproduction, we grouped the anther development into 10 developmental stages according to the characterized cytological events.
Glycosyltransferases aremembers of themultigene family of plants that can transfer single ormulti... more Glycosyltransferases aremembers of themultigene family of plants that can transfer single ormultiple activated sugars to a range of plantmolecules, resulting in the glycosylation of plant compounds. Although the activities of many glycosyltransferases and their products have been recognized for a long time, only in recent years were some glycosyltransferase genes identified and fewhave been functionally characterized in detail. Korean ginseng (Panax ginseng Meyer), belonging to Araliaceae, has been well known as a popularmysteriousmedicinal herb in East Asia for over 2000 years. A total of 704 glycosyltransferase unique sequences have been found from a ginseng expressed sequence tag (EST) library, and these sequences encode enzymes responsible for the secondary metabolite biosynthesis. Finally, twelve UDP glycosyltransferases (UGTs) were selected as the candidates most likely to be involved in triterpenoid synthesis. In this study, we classified the candidate P. ginseng UGTs (PgUGTs) into proper families and groups, which resulted in eight UGT families and six UGT groups. We also investigated those gene candidates encoding for glycosyltransferases by analysis of gene expression in methyl jasmonate (MeJA)-treated ginseng adventitious roots and different tissues from four-year-old ginseng using quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). For organ-specific expression, most of PgUGT transcription levelswere higher in leaves and roots comparedwith flower buds and stems. The transcription of PgUGTs in adventitious roots treated with MeJA increased as compared with the control. PgUGT1 and PgUGT2, which belong to the UGT71 family genes expressed in MeJA-treated adventitious roots, were especially sensitive, showing 33.32 and 38.88-fold expression increases upon 24 h post-treatments, respectively.
Geranylgeranyl-diphosphate synthases (GGDPS) catalyze branch point enzymatic reactions producing ... more Geranylgeranyl-diphosphate synthases (GGDPS) catalyze branch point enzymatic reactions producing isoprenoid-derived products which are necessary for plant growth and responses to a wide range of biotic and abiotic stresses. In our study, full length geranylgeranyl-diphosphate synthase 1 (PgGGDPS1) and 2 (PgGGDPS2) cDNA were isolated and characterized from the flower of Panax ginseng and 4-year old P. ginseng cv. Gumpoong. The cDNA had open reading frame of 1032 and 1116 bp with a deduced amino acid sequence of 343 and 371 residues for GGDPS1 and GGDPS2, respectively. The calculated molecular mass of GGDPS1 and GGDPS2 were approximately 37.66 and 40.21 kDa with a predi-cated isoelectric point of 5.32 and 6.23 and predicted localization of plastid. A GenBank Blast X search revealed that the deduced amino acid of PgGGDPS1 shared a high degree of homology with GGDPS from Panax notoginseng. The transcription pattern of GGDPS genes was different at various developmental stages. Both GGDPS genes were highly expressed in aerial parts of the plant, especially in rapidly growing tissues such as 4-year old flower and stem tissues. Transcript level of PgGGDPS1 was differentially induced in ginseng not only during Pseudomonas syringae pv tomato infection but also after exposure to abiotic stresses. Our results suggested that the induction of GGDPS genes specifically PgGGDPS1 by drought stress may affect chlorophyll levels, intracellular GA content and accumulation of carotenoids as the precursor for higher production of ABA and possibly stomatal closure as the barrier for water loss.
Two novel Gram-staining-positive bacteria, designated DCY60T and DCY90T, were isolated from soil ... more Two novel Gram-staining-positive bacteria, designated DCY60T and DCY90T, were isolated from soil of a ginseng field in the Republic of Korea. 16S rRNA gene sequence comparisons showed the two novel strains were closely related to members of the genus Humibacter with greatest similarity to Humibacter antri KCTC 33009T (98.8 and 98.4 % for DCY60T and DCY90T, respectively). The predominant menaquinones present were MK-11 and MK-12. The major fatty acids were anteiso-C17 : 0 and summed feature 8 containing C18 : 1ω7c and/or C18 : 1ω6c. The DNA G+C contents of strains DCY60T and DCY90T were 62.8 and 66.8 mol%, respectively. The peptidoglycan of both strains contained the amino acids ornithine, 2,4-diaminobutyric acid, alanine, glutamic acid and glycine. The cell-wall sugars of strain DCY60T comprised glucose, galactose, rhamnose and xylose, while strain DCY90T contained glucose, galactose, rhamnose and ribose. The major polar lipids of both strains were phosphatidylglycerol, an unidentified glycolipid, and an unknown phospholipid. On the basis of the phenotypic analysis strains DCY60T and DCY90T represent novel species of the genus Humibacter, for which names Humibacter ginsengiterrae sp. nov. (type strain DCY60T = KCTC 33520T = JCM 30079T) and Humibacter ginsengisoli sp. nov. (type strain DCY90T = KCTC 33521T = JCM 30080T) are proposed.
Ginseng (Panax ginseng), a valued medicinal herb,
is a slow-growing plant that flowers after 3 ye... more Ginseng (Panax ginseng), a valued medicinal herb, is a slow-growing plant that flowers after 3 years of growth with the formation of a solitary terminal umbel inflorescence. However, little is known about cytological events during ginseng reproduction, such as the development of the male organ, the stamen. To better understand the mechanism controlling ginseng male reproductive development, here, we investigated the inflorescence and flower structure of ginseng. Moreover, we performed cytological analysis of anther morphogenesis and showed the common and specialized cytological events including the formation of four concentric cell layers surrounding male reproductive cells followed by subsequent cell differentiation and degeneration of tapetal cells, as well as the formation of mature pollen grains via meiosis and mitosis during ginseng anther development. Particularly, our transverse section and microscopic observations showed that the ginseng tapetal layer exhibits obvious nonsynchronous cell division evidenced by the observation of one or two tapetal layers frequently observed in one anther lobe, suggesting the unique control of cell division. To facilitate the future study on ginseng male reproduction, we grouped the anther development into 10 developmental stages according to the characterized cytological events.
Upon mechanical wounding, plants locally induce necrosis, accumulate methyl jasmonate (MeJA) and ... more Upon mechanical wounding, plants locally induce necrosis, accumulate methyl jasmonate (MeJA) and acquire systemic resistance in nearby tissues. One-month-old in vitro grown Panax ginseng seedlings were treated with either 50 µM MeJA or mechanical wounding alone or a combination of both, to evaluate jasmonic acid (JA) signaling and terpene biosynthetic pathway genes along with terpenoid accumulation. After MeJA treatment, JA pathway genes, such as lipoxygenase (PgLOX), hydrogen peroxidase lyase (PgHPL), allene oxide synthase (PgAOS), and allene oxide cyclase (PgAOC1), and terpene pathway genes, such as isopentenyl diphosphate isomerase (PgIPP) and farnesyl diphosphate synthase (PgFPS), were highly expressed and resulted in the accumulation of mono- and sesquiterpenes. During mechanical wounding, PgLOX expression was induced relatively late after 72 h of treatment, however PgAOC1 was not induced. This resulted in decreased production of MeJA that in turn may have lowered terpenoid production. In contrast, wounding + MeJA treatment increased PgAOC1 and PgLOX gene expression earlier after 6 h and slowly promoted the production of mono- and sesquiterpenes. Furthermore, we monitored the effect of MeJA upon wounding in in vitro grown 1-month-old seedlings treated with MeJA + wounding. These result demonstrated that exogenous MeJA is able to promote recovery from the wounding effect by functioning as a long distance signal. Additionally, these results suggest that exogenous MeJA supplied at the time of mechanical wounding prevents necrosis in the ginseng leaves by increasing the production of terpenoids.
Strain DCY91T
, a Gram-stain-negative, rodshaped,
aerobic, non-motile bacterium, was isolated
... more Strain DCY91T
, a Gram-stain-negative, rodshaped,
aerobic, non-motile bacterium, was isolated
from soil of ginseng field in Gyeonggi province, South
Korea. Strain DCY91T shared the highest 16S rRNA
gene sequence similarity with Sphingomonas mucosissima
DSM 17494T (98.55 %), Sphingomonas dokdonensis
KACC 17420T (98.11 %) and Sphingomonas xinjiangensis
DSM 26736T (96.68 %). The strain DCY91T was
found to able to grow best in trypticase soy agar at 28 °C,
at pH 7 and at 0.5 % NaCl. Ubiquinone 10 was identified
as the isoprenoid quinone. The major polar lipids
were identified as sphingoglycolipid, diphosphatidylglycerol,
phosphatidylethanolamine, phosphatidylglycerol
and phosphatidylcholine. The major fatty acids of strain DCY91T were identified as unsaturated C18:1ω7c and saturated
C16:0. The major polyamine content was sym-homospermidine.
The DNA G + C content was determined to
be 65.8 mol% (HPLC). After 6 days of incubation, strain
DCY91T produced 9.64 ± 1.73 and 33.73 ± 4.66 µg/ml
indole-3-acetic acid, using media without l-tryptophan
and supplemented with l-tryptophan, respectively. Strain
DCY91T was also weakly solubilized phosphate and produced
siderophores. On the basis of the phenotypic characteristics,
genotypic analysis and chemotaxonomic characteristics,
strain DCY91T is considered to represent a
novel species of the genus Sphingomonas, for which the
name Sphingomonas panaciterrae sp. nov. is proposed.
The type strain is DCY91T (=KCTC 42346T =JCM
30807T).
Geranylgeranyl-diphosphate synthases (GGDPS) catalyze branch point enzymatic reactions producing ... more Geranylgeranyl-diphosphate synthases (GGDPS) catalyze branch point enzymatic reactions producing isoprenoid-derived products which are necessary for plant growth and responses to a wide range of biotic and abiotic stresses. In our study, full length geranylgeranyl-diphosphate synthase 1 (PgGGDPS1) and 2 (PgGGDPS2) cDNA were isolated and characterized from the flower of Panax ginseng and 4-year old P. ginseng cv. Gumpoong. The cDNA had open reading frame of 1032 and 1116 bp with a deduced amino acid sequence of 343 and 371 residues for GGDPS1 and GGDPS2, respectively. The calculated molecular mass of GGDPS1 and GGDPS2 were approximately 37.66 and 40.21 kDa with a predicated isoelectric point of 5.32 and 6.23 and predicted localization of plastid. A GenBank Blast X search revealed that the deduced amino acid of PgGGDPS1 shared a high degree of homology with GGDPS from Panax notoginseng. The transcription pattern of GGDPS genes was different at various developmental stages. Both GGDPS genes were highly expressed in aerial parts of the plant, especially in rapidly growing tissues such as 4-year old flower and stem tissues. Transcript level of PgGGDPS1 was differentially induced in ginseng not only during Pseudomonas syringae pv tomato infection but also after exposure to abiotic stresses. Our results suggested that the induction of GGDPS genes specifically PgGGDPS1 by drought stress may affect chlorophyll levels, intracellular GA content and accumulation of carotenoids as the precursor for higher production of ABA and possibly stomatal closure as the barrier for water loss.
A novel bacterial strain, DCY86T (=KCTC 42053T = JCM 19890T) was isolated from soil of a ginseng ... more A novel bacterial strain, DCY86T (=KCTC 42053T = JCM 19890T) was isolated from soil of a ginseng field in Yeoncheon province (38°04′00″N 126°57′00″E), Republic of Korea using a serial dilution method. Strain DCY86T was observed to be Gram-stain negative, strictly aerobic, to grow optimally at 25–30 °C, at pH 7–7.5 and on tryptic soya agar medium. The cells were found to be sensitive to ceftazidine and tetracycline. Based on 16S rRNA gene sequence comparisons, strain DCY86T was found to be most closely related to Cupriavidus basilensis LMG 18990T (98.48 %), Cupriavidus numazensis LMG 26411T (98.34 %), Cupriavidus pinatabonesis KCTC 22125T (98.34 %) and Cupriavidus laharis KCTC 22126T (98.00 %). The G+C content was determined to be 64.23 mol %. The only isoprenoid quinone detected in strain DCY86T was ubiquinone Q-8. The major polar lipids were identified as diphosphatidylglycerol, phosphtidylethanolamine, phosphatidylglycerol, unidentified aminophosphoglycolipids and unidentified phospholipids. The major fatty acids were identified as C16:0 summed feature 3 (C16:1 ω7c/ω6c and/or iso-C15 : 0 2-OH) and summed feature 8 (C18:1 ω7c and/or C18:1 ω6c). These data support the affiliation of strain DCY86T to the genus Cupriavidus. Strain DCY86T was also found to be able to solubilize phosphate and produce siderophores. The results of physiological and biochemical tests enabled strain DCY86T to be differentiated genotypically and phenotypically from the recognized species of the genus Cupriaividus. Therefore, the novel isolate can be considered to represent a novel species, for which the name Cupriavidus yeoncheonense sp. nov. is proposed here. The type strain is DCY86T (=KCTC 42053T = JCM 19890T).
Current agricultural production methods, for example the improper use of chemical fertilizers and... more Current agricultural production methods, for example the improper use of chemical fertilizers and pesticides, create many health and environmental problems. Use of plant growth-promoting bacteria (PGPB) for agricultural benefits is increasing worldwide and also appears to be a trend for the future. There is possibility to develop microbial inoculants for use in agricultural biotechnology, based on these beneficial plant–microbe interactions. For this study, ten bacterial strains were isolated from Yongin forest soil for which in vitro plant-growth promoting trait screenings, such as indole acetic acid (IAA) production, a phosphate solubilization test, and a siderophore production test were used to select two PGPB candidates. Arabidopsis thaliana plants were inoculated with Paenibacillus yonginensis DCY84T and Micrococcus yunnanensis PGPB7. Salt stress, drought stress and heavy metal (aluminum) stress challenges indicated that P. yonginensis DCY84T-inoculated plants were more resistant than control plants. AtRSA1, AtVQ9 and AtWRKY8 were used as the salinity responsive genes. The AtERD15, AtRAB18, and AtLT178 were selected to check A. thaliana responses to drought stress. Aluminum stress response was checked using AtAIP, AtALS3 and AtALMT1. The qRT-PCR results indicated that P. yonginensis DCY84T can promote plant tolerance against salt, drought, and aluminum stress. P. yonginensis DCY84T also showed positive results during in vitro compatibility testing and virulence assay against X. oryzae pv. oryzae Philippine race 6 (PXO99). Better germination rates and growth parameters were also recorded for the P. yonginensis DCY84T Chuchung cultivar rice seed which was grown on coastal soil collected from Suncheon. Based on these results, P. yonginensis DCY84T can be used as a promising PGPB isolate for crop improvement.
Strain DCY85T and DCY85-1T, isolated from rhizosphere of ginseng, were rod-shaped, Gram-reaction-... more Strain DCY85T and DCY85-1T, isolated from rhizosphere of ginseng, were rod-shaped, Gram-reaction-negative, strictly aerobic, catalase positive and oxidase negative. 16S rRNA gene sequence analysis revealed that strain DCY85T as well as DCY85-1T belonged to the genus Burkholderia and were closely related to Burkholderia fungorum KACC 12023T (98.1 and 98.0 % similarity, respectively). The major polar lipids of strain DCY85T and DCY85-1T were phosphatidylethanolamine, one unidentified aminolipid and two unidentified phospholipids. The major fatty acids of both strains are C16:0, C18:1 ω7c and summed feature 3 (C16:1 ω6c and/or C16:1 ω7c). The predominant isoprenoid quinone of each strain DCY85T and DCY85-1T was ubiquinone (Q-8) and the G+C content of their genomic DNA was 66.0 and 59.4 mol%, respectively, which fulfill the characteristic range of the genus Burkholderia. The polyamine content of both DCY85T and DCY85-1T was putrescine. Although both DCY85T and DCY85-1T have highly similar 16S rRNA and identical RecA and gyrB sequences, they show differences in phenotypic and chemotaxonomic characteristics. DNA–DNA hybridization results proved the consideration of both strains as two different species. Based on the results from our polyphasic characterization, strain DCY85T and DCY85-1T are considered novel Burkholderia species for which the name Burkholderia ginsengiterrae sp. nov and Burkholderia panaciterrae sp. nov are, respectively, proposed. An emended description of those strains is also proposed. DCY85T and DCY85-1T showed antagonistic activity against the common root rot pathogen of ginseng, Cylindrocarpon destructans. The proposed type strains are DCY85T (KCTC 42054T = JCM 19888T) and DCY85-1T (KCTC 42055T = JCM 19889T).
Strain DCY84T, a Gram-stain positive, rodshaped,
aerobic, spore-forming bacterium, motile by
me... more Strain DCY84T, a Gram-stain positive, rodshaped,
aerobic, spore-forming bacterium, motile by
means of peritrichous flagella, was isolated fromhumus
soil from Yongin forest in Gyeonggi province, South
Korea. Strain DCY84T shared the highest sequence
similarity with Paenibacillus barengoltzii KACC
15270T (96.86 %), followed by Paenibacillus timonensis
KACC 11491T (96.49 %) and Paenibacillus
phoenicis NBRC 106274T (95.77 %). Strain DCY84T
was found to able to grow best in TSA at temperature
30 C, at pH 8 and at 0.5 % NaCl. MK-7 menaquinone
was identified as the isoprenoid quinone. The major
polar lipids were identified as phosphatidylethanolamine,
an unidentified aminophospholipid, two unidentified
aminolipids and an unidentified polar lipid. The
peptidoglycan was found to contain the amino acids
meso-diaminopimelic acid, alanine and D-glutamic
acid. The major fatty acids of strain DCY84T were
identified as branched chain anteiso-C15:0, saturated
C16:0 and branched chain anteiso-C17:0. The cell wall
sugars of strain DCY84T were found to comprise of
ribose, galactose and xylose. The major polyamine was
identified as spermidine. The DNA G?C content was
determined to be 62.6 mol%. After 6 days of incubation,
strain DCY84T produced 52.96 ± 1.85 and
72.83 ± 2.86 lg/ml L-indole-3-acetic acid, using
media without L-tryptophan and supplemented with Ltryptophan,
respectively. Strain DCY84T was also
found to be able to solubilize phosphate and produce
siderophores. On the basis of the phenotypic characteristics,
genotypic analysis and chemotaxonomic characteristics,
strain DCY84T is considered to represent a
novel species of the genus Paenibacillus, for which the
name Paenibacillus yonginensis sp. nov. is proposed.
The type strain is DCY84T (=KCTC 33428T = JCM
19885T).
Ectopic overexpression of the aluminum-induced protein gene
from Panax ginseng enhances heavy met... more Ectopic overexpression of the aluminum-induced protein gene from Panax ginseng enhances heavy metal tolerance in transgenic Arabidopsis
Glutathione peroxidases (GPXs) are a group of enzymes that protect cells against oxidative damage... more Glutathione peroxidases (GPXs) are a group of enzymes that protect cells against oxidative damage generated by reactive oxygen species (ROS). GPX catalyzes the reduction of hydrogen peroxide (H2O2) or organic hydroperoxides to water or alcohols by reduced glutathione. The presence of GPXs in plants has been reported by several groups, but the roles of individual members of this family in a single plant species have not been studied. Two GPX cDNAs were isolated and characterized from the embryogenic callus of Panax ginseng. The two cDNAs had an open reading frame (ORF) of 723 and 681 bp with a deduced amino acid sequence of 240 and 226 residues, respectively. The calculated molecular mass of the matured proteins are approximately 26.4 kDa or 25.7 kDa with a predicated isoelectric point of 9.16 or 6.11, respectively. The two PgGPXs were elevated strongly by salt stress and chilling stress in a ginseng seedling. In addition, the two PgGPXs showed different responses against biotic stress. The positive responses of PgGPX to the environmental stimuli suggested that ginseng GPX may help to protect against environmental stresses.
Glycosyltransferases aremembers of themultigene family of plants that can transfer single ormulti... more Glycosyltransferases aremembers of themultigene family of plants that can transfer single ormultiple activated sugars to a range of plantmolecules, resulting in the glycosylation of plant compounds. Although the activities of many glycosyltransferases and their products have been recognized for a long time, only in recent years were some glycosyltransferase genes identified and fewhave been functionally characterized in detail. Korean ginseng (Panax ginseng Meyer), belonging to Araliaceae, has been well known as a popularmysteriousmedicinal herb in East Asia for over 2000 years. A total of 704 glycosyltransferase unique sequences have been found from a ginseng expressed sequence tag (EST) library, and these sequences encode enzymes responsible for the secondary metabolite biosynthesis. Finally, twelve UDP glycosyltransferases (UGTs) were selected as the candidates most likely to be involved in triterpenoid synthesis. In this study, we classified the candidate P. ginseng UGTs (PgUGTs) into proper families and groups, which resulted in eight UGT families and six UGT groups. We also investigated those gene candidates encoding for glycosyltransferases by analysis of gene expression in methyl jasmonate (MeJA)-treated ginseng adventitious roots and different tissues from four-year-old ginseng using quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). For organ-specific expression, most of PgUGT transcription levelswere higher in leaves and roots comparedwith flower buds and stems. The transcription of PgUGTs in adventitious roots treated with MeJA increased as compared with the control. PgUGT1 and PgUGT2, which belong to the UGT71 family genes expressed in MeJA-treated adventitious roots, were especially sensitive, showing 33.32 and 38.88-fold expression increases upon 24 h post-treatments, respectively.
Pathogenesis-related proteins (PRs) are known
to function in higher plants as a protein-based def... more Pathogenesis-related proteins (PRs) are known to function in higher plants as a protein-based defensive system against abiotic and biotic stress, particularly pathogen infections. A full-length cDNA sequence of PR BetV1 was isolated and characterized from a 14-year-old ginseng expressed sequence tags library and we named this as PgPR10-4, because of similar identities with previous isolated PgPR10s sequences. The PgPR10-4 gene encodes a 477 bp open reading frame and its deduced protein contains 158 amino acids with a 53 % identity with that of the Actinidia chinensis BetV1 allergen. The expression of PgPR10-4 gene was abundant in leaves and its transcripts showed differentially up-regulated patterns against several ginseng pathogens and abiotic stimuli such as high light and salinity. In addition, PgPR10-4 expression was strongly responsive towards the stress signaling molecules H2O2 and jasmonic acid (JA), while weekly responsive to salicylic acid and abscisic acid. A functional role of PgPR10-4 in environmental stress tolerance was further validated through its overexpression in Arabidopsis. An analysis of T2 transgenic Arabidopsis plants overexpressing the PgPR10-4 gene showed an enhanced tolerance to bacterial and fungal infection, but not to salt stress. When we tagged with cyan fluorescent protein fusion protein, the PgPR10-4-was found to localize to the cytoplasm. The enhanced antifungal activity observed from the Arabidopsis transgenic lines suggests the possible involvement of PgPR10-4 in a defense-related mechanism via the JA signaling pathway.
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(Panax ginseng Meyer), belonging to Araliaceae, has been well known as a popularmysteriousmedicinal herb in
East Asia for over 2000 years. A total of 704 glycosyltransferase unique sequences have been found from a ginseng expressed sequence tag (EST) library, and these sequences encode enzymes responsible for the secondary metabolite biosynthesis. Finally, twelve UDP glycosyltransferases (UGTs) were selected as the candidates most likely to be involved in triterpenoid synthesis. In this study, we classified the candidate P. ginseng UGTs (PgUGTs) into proper families and groups, which resulted in eight UGT families and six UGT groups. We also investigated those gene candidates encoding for glycosyltransferases by analysis of gene expression in methyl
jasmonate (MeJA)-treated ginseng adventitious roots and different tissues from four-year-old ginseng using
quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). For organ-specific expression, most of PgUGT transcription levelswere higher in leaves and roots comparedwith flower buds and stems. The transcription
of PgUGTs in adventitious roots treated with MeJA increased as compared with the control. PgUGT1 and PgUGT2, which belong to the UGT71 family genes expressed in MeJA-treated adventitious roots, were especially sensitive, showing 33.32 and 38.88-fold expression increases upon 24 h post-treatments, respectively.
is a slow-growing plant that flowers after 3 years of growth
with the formation of a solitary terminal umbel inflorescence.
However, little is known about cytological events during ginseng
reproduction, such as the development of the male organ,
the stamen. To better understand the mechanism controlling
ginseng male reproductive development, here, we investigated
the inflorescence and flower structure of ginseng.
Moreover, we performed cytological analysis of anther morphogenesis
and showed the common and specialized cytological
events including the formation of four concentric cell
layers surrounding male reproductive cells followed by subsequent
cell differentiation and degeneration of tapetal cells,
as well as the formation of mature pollen grains via meiosis
and mitosis during ginseng anther development. Particularly,
our transverse section and microscopic observations showed
that the ginseng tapetal layer exhibits obvious nonsynchronous
cell division evidenced by the observation of one or
two tapetal layers frequently observed in one anther lobe,
suggesting the unique control of cell division. To facilitate
the future study on ginseng male reproduction, we grouped
the anther development into 10 developmental stages according
to the characterized cytological events.
, a Gram-stain-negative, rodshaped,
aerobic, non-motile bacterium, was isolated
from soil of ginseng field in Gyeonggi province, South
Korea. Strain DCY91T shared the highest 16S rRNA
gene sequence similarity with Sphingomonas mucosissima
DSM 17494T (98.55 %), Sphingomonas dokdonensis
KACC 17420T (98.11 %) and Sphingomonas xinjiangensis
DSM 26736T (96.68 %). The strain DCY91T was
found to able to grow best in trypticase soy agar at 28 °C,
at pH 7 and at 0.5 % NaCl. Ubiquinone 10 was identified
as the isoprenoid quinone. The major polar lipids
were identified as sphingoglycolipid, diphosphatidylglycerol,
phosphatidylethanolamine, phosphatidylglycerol
and phosphatidylcholine. The major fatty acids of strain DCY91T were identified as unsaturated C18:1ω7c and saturated
C16:0. The major polyamine content was sym-homospermidine.
The DNA G + C content was determined to
be 65.8 mol% (HPLC). After 6 days of incubation, strain
DCY91T produced 9.64 ± 1.73 and 33.73 ± 4.66 µg/ml
indole-3-acetic acid, using media without l-tryptophan
and supplemented with l-tryptophan, respectively. Strain
DCY91T was also weakly solubilized phosphate and produced
siderophores. On the basis of the phenotypic characteristics,
genotypic analysis and chemotaxonomic characteristics,
strain DCY91T is considered to represent a
novel species of the genus Sphingomonas, for which the
name Sphingomonas panaciterrae sp. nov. is proposed.
The type strain is DCY91T (=KCTC 42346T =JCM
30807T).
aerobic, spore-forming bacterium, motile by
means of peritrichous flagella, was isolated fromhumus
soil from Yongin forest in Gyeonggi province, South
Korea. Strain DCY84T shared the highest sequence
similarity with Paenibacillus barengoltzii KACC
15270T (96.86 %), followed by Paenibacillus timonensis
KACC 11491T (96.49 %) and Paenibacillus
phoenicis NBRC 106274T (95.77 %). Strain DCY84T
was found to able to grow best in TSA at temperature
30 C, at pH 8 and at 0.5 % NaCl. MK-7 menaquinone
was identified as the isoprenoid quinone. The major
polar lipids were identified as phosphatidylethanolamine,
an unidentified aminophospholipid, two unidentified
aminolipids and an unidentified polar lipid. The
peptidoglycan was found to contain the amino acids
meso-diaminopimelic acid, alanine and D-glutamic
acid. The major fatty acids of strain DCY84T were
identified as branched chain anteiso-C15:0, saturated
C16:0 and branched chain anteiso-C17:0. The cell wall
sugars of strain DCY84T were found to comprise of
ribose, galactose and xylose. The major polyamine was
identified as spermidine. The DNA G?C content was
determined to be 62.6 mol%. After 6 days of incubation,
strain DCY84T produced 52.96 ± 1.85 and
72.83 ± 2.86 lg/ml L-indole-3-acetic acid, using
media without L-tryptophan and supplemented with Ltryptophan,
respectively. Strain DCY84T was also
found to be able to solubilize phosphate and produce
siderophores. On the basis of the phenotypic characteristics,
genotypic analysis and chemotaxonomic characteristics,
strain DCY84T is considered to represent a
novel species of the genus Paenibacillus, for which the
name Paenibacillus yonginensis sp. nov. is proposed.
The type strain is DCY84T (=KCTC 33428T = JCM
19885T).
from Panax ginseng enhances heavy metal tolerance in transgenic Arabidopsis
reactive oxygen species (ROS). GPX catalyzes the reduction of hydrogen peroxide (H2O2) or organic hydroperoxides
to water or alcohols by reduced glutathione. The presence of GPXs in plants has been reported by several
groups, but the roles of individual members of this family in a single plant species have not been studied. Two
GPX cDNAs were isolated and characterized from the embryogenic callus of Panax ginseng. The two cDNAs had
an open reading frame (ORF) of 723 and 681 bp with a deduced amino acid sequence of 240 and 226 residues,
respectively. The calculated molecular mass of the matured proteins are approximately 26.4 kDa or 25.7 kDa
with a predicated isoelectric point of 9.16 or 6.11, respectively. The two PgGPXs were elevated strongly by salt
stress and chilling stress in a ginseng seedling. In addition, the two PgGPXs showed different responses against
biotic stress. The positive responses of PgGPX to the environmental stimuli suggested that ginseng GPX may
help to protect against environmental stresses.
sugars to a range of plantmolecules, resulting in the glycosylation of plant compounds. Although the activities of
many glycosyltransferases and their products have been recognized for a long time, only in recent years were
some glycosyltransferase genes identified and fewhave been functionally characterized in detail. Korean ginseng
(Panax ginseng Meyer), belonging to Araliaceae, has been well known as a popularmysteriousmedicinal herb in
East Asia for over 2000 years. A total of 704 glycosyltransferase unique sequences have been found from a
ginseng expressed sequence tag (EST) library, and these sequences encode enzymes responsible for the secondary
metabolite biosynthesis. Finally, twelve UDP glycosyltransferases (UGTs) were selected as the candidates
most likely to be involved in triterpenoid synthesis. In this study, we classified the candidate P. ginseng UGTs
(PgUGTs) into proper families and groups, which resulted in eight UGT families and six UGT groups. We also
investigated those gene candidates encoding for glycosyltransferases by analysis of gene expression in methyl
jasmonate (MeJA)-treated ginseng adventitious roots and different tissues from four-year-old ginseng using
quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). For organ-specific expression, most of
PgUGT transcription levelswere higher in leaves and roots comparedwith flower buds and stems. The transcription
of PgUGTs in adventitious roots treated with MeJA increased as compared with the control. PgUGT1 and
PgUGT2, which belong to the UGT71 family genes expressed in MeJA-treated adventitious roots, were especially
sensitive, showing 33.32 and 38.88-fold expression increases upon 24 h post-treatments, respectively.
to function in higher plants as a protein-based defensive
system against abiotic and biotic stress, particularly pathogen
infections. A full-length cDNA sequence of PR
BetV1 was isolated and characterized from a 14-year-old
ginseng expressed sequence tags library and we named this
as PgPR10-4, because of similar identities with previous
isolated PgPR10s sequences. The PgPR10-4 gene encodes
a 477 bp open reading frame and its deduced protein
contains 158 amino acids with a 53 % identity with that of
the Actinidia chinensis BetV1 allergen. The expression of
PgPR10-4 gene was abundant in leaves and its transcripts
showed differentially up-regulated patterns against several
ginseng pathogens and abiotic stimuli such as high light
and salinity. In addition, PgPR10-4 expression was
strongly responsive towards the stress signaling molecules
H2O2 and jasmonic acid (JA), while weekly responsive to
salicylic acid and abscisic acid. A functional role of
PgPR10-4 in environmental stress tolerance was further
validated through its overexpression in Arabidopsis. An
analysis of T2 transgenic Arabidopsis plants overexpressing
the PgPR10-4 gene showed an enhanced tolerance to
bacterial and fungal infection, but not to salt stress. When
we tagged with cyan fluorescent protein fusion protein, the
PgPR10-4-was found to localize to the cytoplasm. The
enhanced antifungal activity observed from the Arabidopsis
transgenic lines suggests the possible involvement
of PgPR10-4 in a defense-related mechanism via the JA
signaling pathway.
(Panax ginseng Meyer), belonging to Araliaceae, has been well known as a popularmysteriousmedicinal herb in
East Asia for over 2000 years. A total of 704 glycosyltransferase unique sequences have been found from a ginseng expressed sequence tag (EST) library, and these sequences encode enzymes responsible for the secondary metabolite biosynthesis. Finally, twelve UDP glycosyltransferases (UGTs) were selected as the candidates most likely to be involved in triterpenoid synthesis. In this study, we classified the candidate P. ginseng UGTs (PgUGTs) into proper families and groups, which resulted in eight UGT families and six UGT groups. We also investigated those gene candidates encoding for glycosyltransferases by analysis of gene expression in methyl
jasmonate (MeJA)-treated ginseng adventitious roots and different tissues from four-year-old ginseng using
quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). For organ-specific expression, most of PgUGT transcription levelswere higher in leaves and roots comparedwith flower buds and stems. The transcription
of PgUGTs in adventitious roots treated with MeJA increased as compared with the control. PgUGT1 and PgUGT2, which belong to the UGT71 family genes expressed in MeJA-treated adventitious roots, were especially sensitive, showing 33.32 and 38.88-fold expression increases upon 24 h post-treatments, respectively.
is a slow-growing plant that flowers after 3 years of growth
with the formation of a solitary terminal umbel inflorescence.
However, little is known about cytological events during ginseng
reproduction, such as the development of the male organ,
the stamen. To better understand the mechanism controlling
ginseng male reproductive development, here, we investigated
the inflorescence and flower structure of ginseng.
Moreover, we performed cytological analysis of anther morphogenesis
and showed the common and specialized cytological
events including the formation of four concentric cell
layers surrounding male reproductive cells followed by subsequent
cell differentiation and degeneration of tapetal cells,
as well as the formation of mature pollen grains via meiosis
and mitosis during ginseng anther development. Particularly,
our transverse section and microscopic observations showed
that the ginseng tapetal layer exhibits obvious nonsynchronous
cell division evidenced by the observation of one or
two tapetal layers frequently observed in one anther lobe,
suggesting the unique control of cell division. To facilitate
the future study on ginseng male reproduction, we grouped
the anther development into 10 developmental stages according
to the characterized cytological events.
, a Gram-stain-negative, rodshaped,
aerobic, non-motile bacterium, was isolated
from soil of ginseng field in Gyeonggi province, South
Korea. Strain DCY91T shared the highest 16S rRNA
gene sequence similarity with Sphingomonas mucosissima
DSM 17494T (98.55 %), Sphingomonas dokdonensis
KACC 17420T (98.11 %) and Sphingomonas xinjiangensis
DSM 26736T (96.68 %). The strain DCY91T was
found to able to grow best in trypticase soy agar at 28 °C,
at pH 7 and at 0.5 % NaCl. Ubiquinone 10 was identified
as the isoprenoid quinone. The major polar lipids
were identified as sphingoglycolipid, diphosphatidylglycerol,
phosphatidylethanolamine, phosphatidylglycerol
and phosphatidylcholine. The major fatty acids of strain DCY91T were identified as unsaturated C18:1ω7c and saturated
C16:0. The major polyamine content was sym-homospermidine.
The DNA G + C content was determined to
be 65.8 mol% (HPLC). After 6 days of incubation, strain
DCY91T produced 9.64 ± 1.73 and 33.73 ± 4.66 µg/ml
indole-3-acetic acid, using media without l-tryptophan
and supplemented with l-tryptophan, respectively. Strain
DCY91T was also weakly solubilized phosphate and produced
siderophores. On the basis of the phenotypic characteristics,
genotypic analysis and chemotaxonomic characteristics,
strain DCY91T is considered to represent a
novel species of the genus Sphingomonas, for which the
name Sphingomonas panaciterrae sp. nov. is proposed.
The type strain is DCY91T (=KCTC 42346T =JCM
30807T).
aerobic, spore-forming bacterium, motile by
means of peritrichous flagella, was isolated fromhumus
soil from Yongin forest in Gyeonggi province, South
Korea. Strain DCY84T shared the highest sequence
similarity with Paenibacillus barengoltzii KACC
15270T (96.86 %), followed by Paenibacillus timonensis
KACC 11491T (96.49 %) and Paenibacillus
phoenicis NBRC 106274T (95.77 %). Strain DCY84T
was found to able to grow best in TSA at temperature
30 C, at pH 8 and at 0.5 % NaCl. MK-7 menaquinone
was identified as the isoprenoid quinone. The major
polar lipids were identified as phosphatidylethanolamine,
an unidentified aminophospholipid, two unidentified
aminolipids and an unidentified polar lipid. The
peptidoglycan was found to contain the amino acids
meso-diaminopimelic acid, alanine and D-glutamic
acid. The major fatty acids of strain DCY84T were
identified as branched chain anteiso-C15:0, saturated
C16:0 and branched chain anteiso-C17:0. The cell wall
sugars of strain DCY84T were found to comprise of
ribose, galactose and xylose. The major polyamine was
identified as spermidine. The DNA G?C content was
determined to be 62.6 mol%. After 6 days of incubation,
strain DCY84T produced 52.96 ± 1.85 and
72.83 ± 2.86 lg/ml L-indole-3-acetic acid, using
media without L-tryptophan and supplemented with Ltryptophan,
respectively. Strain DCY84T was also
found to be able to solubilize phosphate and produce
siderophores. On the basis of the phenotypic characteristics,
genotypic analysis and chemotaxonomic characteristics,
strain DCY84T is considered to represent a
novel species of the genus Paenibacillus, for which the
name Paenibacillus yonginensis sp. nov. is proposed.
The type strain is DCY84T (=KCTC 33428T = JCM
19885T).
from Panax ginseng enhances heavy metal tolerance in transgenic Arabidopsis
reactive oxygen species (ROS). GPX catalyzes the reduction of hydrogen peroxide (H2O2) or organic hydroperoxides
to water or alcohols by reduced glutathione. The presence of GPXs in plants has been reported by several
groups, but the roles of individual members of this family in a single plant species have not been studied. Two
GPX cDNAs were isolated and characterized from the embryogenic callus of Panax ginseng. The two cDNAs had
an open reading frame (ORF) of 723 and 681 bp with a deduced amino acid sequence of 240 and 226 residues,
respectively. The calculated molecular mass of the matured proteins are approximately 26.4 kDa or 25.7 kDa
with a predicated isoelectric point of 9.16 or 6.11, respectively. The two PgGPXs were elevated strongly by salt
stress and chilling stress in a ginseng seedling. In addition, the two PgGPXs showed different responses against
biotic stress. The positive responses of PgGPX to the environmental stimuli suggested that ginseng GPX may
help to protect against environmental stresses.
sugars to a range of plantmolecules, resulting in the glycosylation of plant compounds. Although the activities of
many glycosyltransferases and their products have been recognized for a long time, only in recent years were
some glycosyltransferase genes identified and fewhave been functionally characterized in detail. Korean ginseng
(Panax ginseng Meyer), belonging to Araliaceae, has been well known as a popularmysteriousmedicinal herb in
East Asia for over 2000 years. A total of 704 glycosyltransferase unique sequences have been found from a
ginseng expressed sequence tag (EST) library, and these sequences encode enzymes responsible for the secondary
metabolite biosynthesis. Finally, twelve UDP glycosyltransferases (UGTs) were selected as the candidates
most likely to be involved in triterpenoid synthesis. In this study, we classified the candidate P. ginseng UGTs
(PgUGTs) into proper families and groups, which resulted in eight UGT families and six UGT groups. We also
investigated those gene candidates encoding for glycosyltransferases by analysis of gene expression in methyl
jasmonate (MeJA)-treated ginseng adventitious roots and different tissues from four-year-old ginseng using
quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). For organ-specific expression, most of
PgUGT transcription levelswere higher in leaves and roots comparedwith flower buds and stems. The transcription
of PgUGTs in adventitious roots treated with MeJA increased as compared with the control. PgUGT1 and
PgUGT2, which belong to the UGT71 family genes expressed in MeJA-treated adventitious roots, were especially
sensitive, showing 33.32 and 38.88-fold expression increases upon 24 h post-treatments, respectively.
to function in higher plants as a protein-based defensive
system against abiotic and biotic stress, particularly pathogen
infections. A full-length cDNA sequence of PR
BetV1 was isolated and characterized from a 14-year-old
ginseng expressed sequence tags library and we named this
as PgPR10-4, because of similar identities with previous
isolated PgPR10s sequences. The PgPR10-4 gene encodes
a 477 bp open reading frame and its deduced protein
contains 158 amino acids with a 53 % identity with that of
the Actinidia chinensis BetV1 allergen. The expression of
PgPR10-4 gene was abundant in leaves and its transcripts
showed differentially up-regulated patterns against several
ginseng pathogens and abiotic stimuli such as high light
and salinity. In addition, PgPR10-4 expression was
strongly responsive towards the stress signaling molecules
H2O2 and jasmonic acid (JA), while weekly responsive to
salicylic acid and abscisic acid. A functional role of
PgPR10-4 in environmental stress tolerance was further
validated through its overexpression in Arabidopsis. An
analysis of T2 transgenic Arabidopsis plants overexpressing
the PgPR10-4 gene showed an enhanced tolerance to
bacterial and fungal infection, but not to salt stress. When
we tagged with cyan fluorescent protein fusion protein, the
PgPR10-4-was found to localize to the cytoplasm. The
enhanced antifungal activity observed from the Arabidopsis
transgenic lines suggests the possible involvement
of PgPR10-4 in a defense-related mechanism via the JA
signaling pathway.