Secondary Xylem
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Recent papers in Secondary Xylem
• Premise of the Study: Secondary xylem (wood) produced by a vascular cambium supports increased plant size and underpins the most successful model of arborescence among tracheophytes. Woody plants established the extensive forest... more
• Premise of the Study: Secondary xylem (wood) produced by a vascular cambium supports increased plant size and underpins
the most successful model of arborescence among tracheophytes. Woody plants established the extensive forest ecosystems that dramatically changed the Earth’s biosphere. Secondary growth evolved in several lineages in the Devonian, but only two occurrences have been reported previously from the Early Devonian. The evolutionary history and phylogeny of wood production are poorly understood, and Early Devonian plants are key to illuminating them.
• Methods: A fossil plant preserved anatomically by cellular permineralization in the Lower Devonian (Emsian, ca. 400–395
million years old) Battery Point Formation of Gaspé Bay (Quebec, Canada) is described using the cellulose acetate peel
technique.
• Key Results: The plant, Franhueberia gerriennei Hoffman et Tomescu gen. et sp. nov., is a basal euphyllophyte with a centrarch protostele and metaxylem tracheids with circular and oval to scalariform bordered multiaperturate pits (P-type tracheids). The outer layers of xylem, consisting of larger-diameter P-type tracheids, exhibit the features diagnostic of secondary xylem: radial fi les of tracheids, multiplicative divisions, and a combination of axial and radial components.
• Conclusions: Franhueberia is one of the three oldest euphyllophytes exhibiting secondary growth documented in the Early Devonian. Within the euphyllophyte clade, these plants represent basal lineages that predate the evolution of stem-leaf-root organography and indicate that underlying mechanisms for secondary growth became part of the euphyllophyte developmental toolkit very early in the clade’s evolution.
the most successful model of arborescence among tracheophytes. Woody plants established the extensive forest ecosystems that dramatically changed the Earth’s biosphere. Secondary growth evolved in several lineages in the Devonian, but only two occurrences have been reported previously from the Early Devonian. The evolutionary history and phylogeny of wood production are poorly understood, and Early Devonian plants are key to illuminating them.
• Methods: A fossil plant preserved anatomically by cellular permineralization in the Lower Devonian (Emsian, ca. 400–395
million years old) Battery Point Formation of Gaspé Bay (Quebec, Canada) is described using the cellulose acetate peel
technique.
• Key Results: The plant, Franhueberia gerriennei Hoffman et Tomescu gen. et sp. nov., is a basal euphyllophyte with a centrarch protostele and metaxylem tracheids with circular and oval to scalariform bordered multiaperturate pits (P-type tracheids). The outer layers of xylem, consisting of larger-diameter P-type tracheids, exhibit the features diagnostic of secondary xylem: radial fi les of tracheids, multiplicative divisions, and a combination of axial and radial components.
• Conclusions: Franhueberia is one of the three oldest euphyllophytes exhibiting secondary growth documented in the Early Devonian. Within the euphyllophyte clade, these plants represent basal lineages that predate the evolution of stem-leaf-root organography and indicate that underlying mechanisms for secondary growth became part of the euphyllophyte developmental toolkit very early in the clade’s evolution.
RESUMEN El xilema secundario es el componente más abundante de la biomasa vegetal. Por tanto, conocer los genes que regulan su formación ayudaría a diseñar estrategias para el mejoramiento genético de la madera. Así, el objetivo de este... more
RESUMEN
El xilema secundario es el componente más abundante de la biomasa vegetal. Por tanto, conocer los genes que regulan su formación ayudaría a diseñar estrategias para el mejoramiento genético de la madera. Así, el objetivo de este trabajo fue realizar el análisis computacional de la estructura primaria y secundaria del factor de transcripción (FT) TgNACO1 de Tectona grandis, además de evaluar su historia evolutiva, dominios conservados y expresión génica en tejidos lignificados de árboles de 12 y 60 años. Para ello, se realizó una evaluación del potencial de interacción ion-electrón (PIIE), mediante el método del espectro de la información (MEI) utilizando la librería SFAPS de R-Project, seguido del modelamiento estructural utilizando el software MODELLER y visualizado mediante PyMol. Además, el análisis de alineamiento de secuencia múltiple y filogenia fue mediante el software Bioedit y MrBayes respectivamente. También se evaluó los niveles de síntesis del FT TgNACO1 mediante qRT-PCR. Como resultados, se evidenció que el FT mantiene una estructura (3-hoja antiparalela retorcida, que se compacta contra una a-hélice en la región N-terminal, teniendo así tres dominios a hélice y siete dominios (3 plegada. Asimismo, mediante el MEI se demostró que tiene alrededor de cinco funciones biológicas y mutaciones sobre los aminoácidos con mayor PIIE, lo que conlleva a evoluciones sobre las redes de regulación genética. Finalmente, el FT TgNACO1 podría presentar un papel fundamental en la organización y desarrollo de las partes que componen la albura, como las células radiales de la zona cambial, los vasos, fibras y los anillos de crecimiento.
ABSTRACT
Secondary xylem is the most abundant component of plant biomass. Therefore, knowing the genes that regulate its formation would help to design strategies for wood genetic improvement. Thus, the objective of this work was to perform computational analysis of the primary and secondary structure of the TgNACO1 transcription factor (FT) of Tectona grandis, and to evaluate its evolutionary history, conserved domains and gene expression in lignified tissues of trees with 12 and 60 years old. For this, an ion-electron interaction potential (IEP) was evaluated using the information-spectrum method (IEM) using the R-Project and SFAPS library, followed by structural modeling using the MODELLER software and visualized by PyMol program. In addition, the analysis of multiple sequence alignment and phylogeny was performed using Bioedit and MrBayes software, respectively. We also evaluated the qRT-PCR levels of TgNACO1. As results, it was found that TgNACO1 maintains a twisted antiparallel 3-sheet structure, which is compacted against an a-helix in the N-terminal region, having three a-helix domains and seven folded ((-domains. Also, through the IEM, it was demonstrated that it has about five biological functions, and mutations on amino acids with higher IEP, which leads to evolutions on genetic regulation networks. Finally, the FT TgNACO1 could play an esential role in the organization and development of the parts that make up the sapwood, such as the radial cells of the cambial zone, the vessels, fibers and the growth rings.
El xilema secundario es el componente más abundante de la biomasa vegetal. Por tanto, conocer los genes que regulan su formación ayudaría a diseñar estrategias para el mejoramiento genético de la madera. Así, el objetivo de este trabajo fue realizar el análisis computacional de la estructura primaria y secundaria del factor de transcripción (FT) TgNACO1 de Tectona grandis, además de evaluar su historia evolutiva, dominios conservados y expresión génica en tejidos lignificados de árboles de 12 y 60 años. Para ello, se realizó una evaluación del potencial de interacción ion-electrón (PIIE), mediante el método del espectro de la información (MEI) utilizando la librería SFAPS de R-Project, seguido del modelamiento estructural utilizando el software MODELLER y visualizado mediante PyMol. Además, el análisis de alineamiento de secuencia múltiple y filogenia fue mediante el software Bioedit y MrBayes respectivamente. También se evaluó los niveles de síntesis del FT TgNACO1 mediante qRT-PCR. Como resultados, se evidenció que el FT mantiene una estructura (3-hoja antiparalela retorcida, que se compacta contra una a-hélice en la región N-terminal, teniendo así tres dominios a hélice y siete dominios (3 plegada. Asimismo, mediante el MEI se demostró que tiene alrededor de cinco funciones biológicas y mutaciones sobre los aminoácidos con mayor PIIE, lo que conlleva a evoluciones sobre las redes de regulación genética. Finalmente, el FT TgNACO1 podría presentar un papel fundamental en la organización y desarrollo de las partes que componen la albura, como las células radiales de la zona cambial, los vasos, fibras y los anillos de crecimiento.
ABSTRACT
Secondary xylem is the most abundant component of plant biomass. Therefore, knowing the genes that regulate its formation would help to design strategies for wood genetic improvement. Thus, the objective of this work was to perform computational analysis of the primary and secondary structure of the TgNACO1 transcription factor (FT) of Tectona grandis, and to evaluate its evolutionary history, conserved domains and gene expression in lignified tissues of trees with 12 and 60 years old. For this, an ion-electron interaction potential (IEP) was evaluated using the information-spectrum method (IEM) using the R-Project and SFAPS library, followed by structural modeling using the MODELLER software and visualized by PyMol program. In addition, the analysis of multiple sequence alignment and phylogeny was performed using Bioedit and MrBayes software, respectively. We also evaluated the qRT-PCR levels of TgNACO1. As results, it was found that TgNACO1 maintains a twisted antiparallel 3-sheet structure, which is compacted against an a-helix in the N-terminal region, having three a-helix domains and seven folded ((-domains. Also, through the IEM, it was demonstrated that it has about five biological functions, and mutations on amino acids with higher IEP, which leads to evolutions on genetic regulation networks. Finally, the FT TgNACO1 could play an esential role in the organization and development of the parts that make up the sapwood, such as the radial cells of the cambial zone, the vessels, fibers and the growth rings.