拟南芥微丝加帽蛋白β亚基参与壳梭孢素诱导的气孔开放过程  

The Capping Proteinβ-Subunit Mediates Fusicoccin-induced Stomatal Movement in Arabidopsis

作　　者：王攀 李昭 赵盖晴 武玥冉 豆丽茹 于荣[1] WANG Pan;LI Zhao;ZHAO Ge-Qing;WU Yue-Ran;DOU Li-Ru;YU Rong(College of Life Sciences,Capital Normal University,Beijing 100048;College of Biology,China Agricultural University,Beijing 100193)

机构地区：[1]首都师范大学生命科学学院,北京100048 [2]中国农业大学生物学院,北京100193

出　　处：《中国生物化学与分子生物学报》2022年第5期648-657,共10页Chinese Journal of Biochemistry and Molecular Biology

基　　金：国家自然科学基金(No.31871351)资助。

摘　　要：气孔是植物响应外源信号,与环境进行水分和气体交换的门户。由外源信号引起的保卫细胞微丝骨架动态变化在气孔运动中发挥重要作用,但是具体的精确调节机制仍不清楚。微丝结合蛋白家族(ABPs)是微丝动态组装最直接的调控者,它们的作用不容忽视。本文运用反向遗传学,以微丝结合蛋白—加帽蛋白(CP)β-亚基(CPB)突变体cpb-3为实验材料,探究其在壳梭孢素(FC)诱导气孔开放中的作用。结果发现:离体叶片干燥3 h,cpb-3突变体的叶片失水率为63.45%,明显高于野生型的48.99%。气孔开度测量及激光共聚焦显微镜观察发现,cpb-3突变体的气孔开放程度以及微丝动态重排对FC分子更敏感。气孔开度相比野生型增大了20%(P<0.05),含辐射状微丝排布的保卫细胞数量比例增幅达到58.3%,比对照组高出18.5%。此外,非损伤微测技术记录保卫细胞Ca^(2+)、K^(+)等跨膜运输动态,FC处理下,cpb-3突变体保卫细胞中Ca^(2+)外流速度升至212.86 pmol cm^(-2)s^(-1),野生型仅为68.76 pmol cm^(-2)s^(-1),明显快于野生型。且K^(+)内流也有相同表现。综上表明,微丝加帽蛋白CP的β亚基CPB可能通过调节保卫细胞微丝骨架动态重排以及离子流动,在FC诱导的气孔运动中发挥重要的作用。Actin dynamics in guard cells play a critical role in stomatal movement.Remodeling of actin arrays is triggered by different biotic and abiotic stimuli,which requires precise control.However,the molecular mechanism underlying this process is not well understood.Here we investigated whether and how the capping protein(CP)regulates actin filaments during fusicoccin(FC)-induced stomatal opening.We found that both stomatal opening and F-actin rearrangement are sensitive in the Capping Proteinβ-subunit(CPB)cpb-3 mutants,which resulted in its hypersensitivity to drought stress.The leaves detached from cpb-3 had a higher water loss rate(63.45%)than from the wild type(48.99%),and the stomatal aperture of cpb-3 was about 20%greater than in the wild type.After 1 h of FC treatment,the proportion of cpb-3 guard cells with radial actin arrays increased to 65.5%dramatically,while only approximately 47.2%guard cells in WT exhibited transversely oriented actin filaments.Moreover,the record of transmembrane Ca^(2+)fluxes by the non-invasive micro-test technique(NMT)showed that FC-induced rapid Ca^(2+)transport was more obvious in cpb-3 guard cells,with a mean efflux of 212.86 pmol cm^(-2)s^(-1) compared with 68.76 pmol cm^(-2)s^(-1) in the wild type.K^(+)influx occurred as the same pattern.Collectively,our data suggest that CPB plays an important role in FC-induced stomatal movement through the regulation of actin dynamics and ion flux(Ca^(2+),K^(+)etc.).

关 键 词：气孔运动 微丝骨架动态 加帽蛋白 壳梭孢素 

分 类 号：Q28[生物学—细胞生物学]