1.
Xyloglucan Remodeling Defines Auxin-Dependent Differential Tissue Expansion in Plants.
Velasquez, SM, Guo, X, Gallemi, M, Aryal, B, Venhuizen, P, Barbez, E, Dünser, KA, Darino, M, Pĕnčík, A, Novák, O, et al
International journal of molecular sciences. 2021;(17)
Abstract
Size control is a fundamental question in biology, showing incremental complexity in plants, whose cells possess a rigid cell wall. The phytohormone auxin is a vital growth regulator with central importance for differential growth control. Our results indicate that auxin-reliant growth programs affect the molecular complexity of xyloglucans, the major type of cell wall hemicellulose in eudicots. Auxin-dependent induction and repression of growth coincide with reduced and enhanced molecular complexity of xyloglucans, respectively. In agreement with a proposed function in growth control, genetic interference with xyloglucan side decorations distinctly modulates auxin-dependent differential growth rates. Our work proposes that auxin-dependent growth programs have a spatially defined effect on xyloglucan's molecular structure, which in turn affects cell wall mechanics and specifies differential, gravitropic hypocotyl growth.