In vivo single-particle tracking of the aquaporin AtPIP2;1 in stomata reveals cell type-specific dynamics
In vivo single-particle tracking of the aquaporin AtPIP2;1 in stomata reveals cell type-specific dynamics
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DOI：
10.1093/plphys/kiab007
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发表时间：
2021-01-13
期刊：
影响因子：
7.4
通讯作者：
Li, Xiaojuan
中科院分区：
文献类型：
--
作者：
Cui, Yaning;Zhao, Yanxia;Li, Xiaojuan
水通道蛋白，如质膜内在蛋白（PIP）允许水通过细胞膜移动，并且对于植物中的气孔运动至关重要。尽管它们的重要性，水通道蛋白在水流出和流入过程中的动态变化还没有在体内真实的时间直接观察到。在这里，以确定哪些因素调节这些变化的双向易位的水，我们研究了气孔免疫反应过程中的水通道蛋白的动态细菌鞭毛蛋白衍生肽flg 22。拟南芥（Arabidopsis thaliana）水通道蛋白突变体pip 2;1在flg 22诱导的气孔反应中表现出缺陷。可变角度全内反射荧光显微镜显示，AQ 6] GFP-AtPIP 2;1在保卫细胞和附属细胞中的运动动力学和停留时间表现出对flg 22的细胞类型特异性依赖性。细胞骨架，而不是细胞壁，是调节AtPIP 2;1动力学的主要因素，虽然细胞骨架和细胞壁可能形成有界域，限制AtPIP 2;1在保卫细胞和附属细胞中的扩散。最后，我们的分析揭示了不同的作用，皮层肌动蛋白和微管在调节AtPIP 2;1动态保卫细胞，以及辅助细胞，在各种条件下。我们的观察揭示了调节植物对病原体的膜蛋白动态的异质性机制。
Aquaporins such as the plasma membrane intrinsic proteins (PIPs) allow water to move through cell membranes and are vital for stomatal movement in plants. Despite their importance, the dynamic changes in aquaporins during water efflux and influx have not been directly observed in real time in vivo. Here, to determine which factors regulate these changes during the bidirectional translocation of water, we examined aquaporin dynamics during the stomatal immune response to the bacterial flagellin-derived peptide flg22. The Arabidopsis (Arabidopsis thaliana) aquaporin mutant pip2;1 showed defects in the flg22-induced stomatal response. Variable-angle total internal reflection fluorescence microscopy revealed that the movement dynamics and dwell times of AQ6]GFP-AtPIP2;1 in guard cells and subsidiary cells exhibited cell type-specific dependencies on flg22. The cytoskeleton, rather than the cell wall, was the major factor regulating AtPIP2;1 dynamics, although both the cytoskeleton and cell wall might form bounded domains that restrict the diffusion of AtPIP2;1 in guard cells and subsidiary cells. Finally, our analysis revealed the different roles of cortical actin and microtubules in regulating AtPIP2;1 dynamics in guard cells, as well as subsidiary cells, under various conditions. Our observations shed light on the heterogeneous mechanisms that regulate membrane protein dynamics in plants in response to pathogens.