Department of Plant Sciences, University of Oxford, OX1 3RB Oxford, United Kingdom.
Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas (CSIC)-Universitat Politècnica de València (UPV), 46022 Valencia, Spain.
Proc Natl Acad Sci U S A. 2019 Sep 10;116(37):18710-18716. doi: 10.1073/pnas.1807863116. Epub 2019 Aug 23.
In plants, secondary growth results in radial expansion of stems and roots, generating large amounts of biomass in the form of wood. Using genome-wide association studies (GWAS)-guided reverse genetics in , we discovered , previously known to control plant immunoresponses and abscission, as a regulator of secondary growth. We present anatomical, genetic, and molecular evidence indicating that SOBIR1/EVR prevents the precocious differentiation of xylem fiber, a key cell type for wood development. SOBIR1/EVR acts through a mechanism that involves BREVIPEDICELLUS (BP) and ERECTA (ER), 2 proteins previously known to regulate xylem fiber development. We demonstrate that BP binds promoter and that expression is enhanced in mutants, suggesting a direct, negative regulation of BP over expression. We show that SOBIR1/EVR physically interacts with ER and that defects caused by the mutation are aggravated by mutating , indicating that SOBIR1/EVR and ERECTA act together in the control of the precocious formation of xylem fiber development.
在植物中，次生生长导致茎和根的径向扩张，以木材的形式产生大量生物质。利用全基因组关联研究（GWAS）指导的反向遗传学，我们发现以前已知控制植物免疫反应和脱落的 SOBIR1/EVR 是次生生长的调节剂。我们提出了解剖学、遗传学和分子证据，表明 SOBIR1/EVR 可防止木质部纤维的过早分化，木质部纤维是木材发育的关键细胞类型。SOBIR1/EVR 通过一种涉及 BREVIPEDICELLUS（BP）和 ERECTA（ER）的机制起作用，这两种蛋白质先前已知可调节木质部纤维的发育。我们证明了 BP 结合 启动子，并且在 突变体中表达增强，这表明 BP 对 表达的直接负调控。我们表明 SOBIR1/EVR 与 ER 物理相互作用，并且由 突变引起的缺陷因突变 而加重，这表明 SOBIR1/EVR 和 ERECTA 一起作用于控制木质部纤维发育的过早形成。
