Arabidopsis leucine-rich repeat extensin (LRX) proteins modify cell wall composition and influence plant growth

作者：Christian Draeger, Tohnyui Ndinyanka Fabrice, Emilie Gineau, Grégory Mouille, Benjamin M. Kuhn, Isabel Møller, Marie‐Therese Abdou, Beat Frey, Markus Pauly, Antony Bacic, Christoph Ringli · 发表于：BMC Plant Biology · 年份：2015 · DOI：10.1186/s12870-015-0548-8 · 被引用次数：127 · 研究领域：Polysaccharides and Plant Cell Walls、Plant Molecular Biology Research、Plant Reproductive Biology

BACKGROUND: Leucine-rich repeat extensins (LRXs) are extracellular proteins consisting of an N-terminal leucine-rich repeat (LRR) domain and a C-terminal extensin domain containing the typical features of this class of structural hydroxyproline-rich glycoproteins (HRGPs). The LRR domain is likely to bind an interaction partner, whereas the extensin domain has an anchoring function to insolubilize the protein in the cell wall. Based on the analysis of the root hair-expressed LRX1 and LRX2 of Arabidopsis thaliana, LRX proteins are important for cell wall development. The importance of LRX proteins in non-root hair cells and on the structural changes induced by mutations in LRX genes remains elusive. RESULTS: The LRX gene family of Arabidopsis consists of eleven members, of which LRX3, LRX4, and LRX5 are expressed in aerial organs, such as leaves and stem. The importance of these LRX genes for plant development and particularly cell wall formation was investigated. Synergistic effects of mutations with gradually more severe growth retardation phenotypes in double and triple mutants suggest a similar function of the three genes. Analysis of cell wall composition revealed a number of changes to cell wall polysaccharides in the mutants. CONCLUSIONS: LRX3, LRX4, and LRX5, and most likely LRX proteins in general, are important for cell wall development. Due to the complexity of changes in cell wall structures in the lrx mutants, the exact function of LRX proteins remains to be determ...