A dirigent protein complex directs lignin polymerization and assembly of the root diffusion barrier.
A dirigent protein complex directs lignin polymerization and assembly of the root diffusion barrier.
复制标题
定向蛋白复合物指导木质素聚合和根扩散屏障的组装。
DOI：
10.1126/science.adi5032
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Gao YQ
中科院分区：
文献类型：
--
作者：
Gao YQ
在功能上类似于动物肠道中的紧密连接，植物根已经进化出木质化的卡斯帕里斯带，作为内皮层的细胞外扩散屏障，以密封根外质并维持营养平衡。这种扩散屏障的结构已经部分确定，但其木质素聚合和组装步骤仍然难以捉摸。在这里，我们描述了一个对木质素的局部聚合至关重要的直接蛋白家族（DPs），这是卡斯帕里斯条带在细胞壁中生物形成所必需的，也是卡斯帕里斯条带附着在质膜上以密封外质体所必需的。我们揭示了一种需要DPs和申根途径之间合作的Casparian条状木质化机制。此外，我们证明DPs直接介导木质素聚合作为该机制的一部分。
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.