A dirigent protein complex directs lignin polymerization and assembly of the root diffusion barrier

• 成果类型: Article
• 署名作者: Gao, Yi-Qun; Huang, Jin-Quan; Reyt, Guilhem; Song, Tao; Love, Ashley; Tiemessen, David; Xue, Pei-Ying; Wu, Wen-Kai; George, Michael W.; Chen, Xiao-Ya; Chao, Dai-Yin; Castrillo, Gabriel; Salt, David E.
• 署名单位: University of Nottingham; University of Nottingham; Chinese Academy of Sciences; Center for Excellence in Molecular Plant Sciences, CAS; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS; University of Nottingham; Hebei Agricultural University
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-12499
• DOI: 10.1126/science.adi5032
• 发表日期: 2023-10-27
• 页码: 464-471
• 关键词: casparian strip; arabidopsis; mutants; mechanism; FAMILY; genes

摘要

Functionally similar to the tight junctions present in animal guts, plant roots have evolved a lignified Casparian strip as an extracellular diffusion barrier in the endodermis to seal the root apoplast and maintain nutrient homeostasis. How this diffusion barrier is structured has been partially defined, but its lignin polymerization and assembly steps remain elusive. Here, we characterize a family of dirigent proteins (DPs) essential for both the localized polymerization of lignin required for Casparian strip biogenesis in the cell wall and for attachment of the strip to the plasma membrane to seal the apoplast. We reveal a Casparian strip lignification mechanism that requires cooperation between DPs and the Schengen pathway. Furthermore, we demonstrate that DPs directly mediate lignin polymerization as part of this mechanism.