Cell Biology, Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany.
Centre for Integrative Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany.
Plant Cell. 2020 May;32(5):1689-1702. doi: 10.1105/tpc.19.00777. Epub 2020 Feb 25.
The initiation of intracellular host cell colonization by symbiotic rhizobia in requires repolarization of root hairs, including the rearrangement of cytoskeletal filaments. The molecular players governing microtubule (MT) reorganization during rhizobial infections remain to be discovered. Here, we identified DEVELOPMENTALLY REGULATED PLASMA MEMBRANE POLYPEPTIDE (DREPP), a member of the MT binding DREPP/PCaP protein family, and investigated its functions during rhizobial infections. We show that rhizobial colonization of mutant roots as well as transgenic roots overexpressing DREPP is impaired. DREPP relocalizes into symbiosis-specific membrane nanodomains in a stimulus-dependent manner. This subcellular segregation coincides with DREPP-dependent MT fragmentation and a partial loss of the ability to reorganize the MT cytoskeleton in response to rhizobia, which might rely on an interaction between DREPP and the MT-organizing protein SPIRAL2. Taken together, our results reveal that establishment of symbiotic associations in requires DREPP in order to regulate MT reorganization during initial root hair responses to rhizobia.
共生根瘤菌在 中起始细胞内宿主细胞定殖需要根毛的再极化，包括细胞骨架丝的重排。目前仍有待发现调控根瘤菌感染过程中微管（MT）重组的分子参与者。在这里，我们鉴定了发育调控的质膜多肽（DREPP），它是 MT 结合 DREPP/PCaP 蛋白家族的成员，并研究了其在根瘤菌感染过程中的功能。我们表明，突变体根中的根瘤菌定殖以及过表达 DREPP 的转基因根的定殖受到损害。DREPP 以刺激依赖性方式重新定位到共生特异性膜纳米域中。这种亚细胞分隔与 DREPP 依赖的 MT 片段化以及对根瘤菌响应的 MT 细胞骨架重新排列能力的部分丧失相吻合，这可能依赖于 DREPP 和 MT 组织蛋白 SPIRAL2 之间的相互作用。总之，我们的结果表明，共生关联的建立需要 DREPP 来调节初始根毛对根瘤菌反应过程中的 MT 重组。
