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Proc Natl Acad Sci U S A. 2019 Sep 10;116(37):18710-18716. doi: 10.1073/pnas.1807863116. Epub 2019 Aug 23.

SOBIR1/EVR prevents precocious initiation of fiber differentiation during wood development through a mechanism involving BP and ERECTA.

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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.
Department of Plant Sciences, University of Oxford, OX1 3RB Oxford, United Kingdom;


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 Arabidopsis thaliana, we discovered SOBIR1/EVR, 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 SOBIR1/EVR promoter and that SOBIR1/EVR expression is enhanced in bp mutants, suggesting a direct, negative regulation of BP over SOBIR1/EVR expression. We show that SOBIR1/EVR physically interacts with ER and that defects caused by the sobir1/evr mutation are aggravated by mutating ER, indicating that SOBIR1/EVR and ERECTA act together in the control of the precocious formation of xylem fiber development.


cambium; meristem; wood development; xylem

[Available on 2020-02-23]

Conflict of interest statement

The authors declare no conflict of interest.

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