棉花GhWLIM5在棉纤维发育中的功能分析  

Function Analysis of Cotton GhWLIM5 in Cotton Fiber Development

作　　者：张世鹏 刘文丽 程昌豪 李学宝[1] 李扬[1] ZHANG Shipeng;LIU Wenli;CHENG Changhao;LI Xuebao;LI Yang(Hubei Key Laboratory of Genetic Regulation and Integrative Biology/School of Life Sciences,Central China Normal University,Wuhan 430079,China)

机构地区：[1]华中师范大学生命科学学院/遗传调控与整合生物学湖北省重点实验室,湖北武汉430079

出　　处：《山西农业科学》2023年第9期974-982,共9页Journal of Shanxi Agricultural Sciences

基　　金：农业部转基因专项(2016ZX08009003);国家自然科学基金面上项目(32172039)。

摘　　要：LIM结构域蛋白是重要的发育调控因子,常作为肌动蛋白结合蛋白(F-Actin)参与调控细胞骨架建成。为了进一步研究GhWLIM5在棉纤维中的生物学功能,通过研究棉花的遗传转化并获得相应的转基因植株,同时对多株转基因植株进行表型分析,并通过分子试验对棉花LIM蛋白GhWLIM5在棉花纤维发育中的功能进行相关研究。结果表明,与野生型相比,抑制GhWLIM5表达的GhWLIM5 RNAi转基因棉花纤维中肌动蛋白细胞骨架较为稀疏,细胞生长速度降低,成熟纤维较短,纤维强度较弱。通过低速共沉淀检测发现,GhWLIM5促进F-Actin成束的能力与pH环境密切相关,随着pH值的升高,GhWLIM5促进F-Actin成束的能力逐渐下降。高速共沉淀结果显示,加入同等浓度F-Actin的情况下,经高速离心,GhXLIM6存在于沉淀中的比例明显高于GhWLIM5,说明GhWLIM5结合F-Actin的能力弱于GhXLIM6。纤维品质分析表明,抑制GhWLIM5的表达还会影响棉纤维次生壁的发育;但实时荧光定量结果显示,与野生型相比,转基因棉花纤维中这些纤维素合酶基因GhCESA4/7/8的表达并未发生明显变化,说明GhWLIM5可能不直接影响棉纤维次生壁发育。研究结果揭示,GhWLIM5通过结合并维持动态的F-Actin细胞骨架在棉纤维伸长生长中起重要作用。LIM domain proteins are important development regulatory factors,and often involved as an actin binding protein(F-Action)in regulating cytoskeleton construction.To further explore the biological function of GhWLIM5 in cotton fiber,in this study,corresponding transgenic plants were obtained by studying the genetic transformation of cotton.At the same time,the phenotypes of several transgenic plants were analyzed,and the function of GhWLIM5 of cotton LIM protein in cotton fiber development was studied by molecular experiments.The results showed that compared with the wild type,the actin cytoskeleton in the fiber of GhWLIM5 RNAi transgenic cotton inhibiting GhWLIM5 expression was relatively sparse,cell growth rate decreased,mature fibers were shorter,and fiber strength was weaker.Low-speed cosedimentation assay showed that the ability of GhWLIM5 to promote F-Actin bundles was closely related to the pH environment.With the increase of pH,the ability of GhWLIM5 to promote F-Actin bundles gradually decreased.The results of high-speed cosedimentation showed that when the same concentration of F-Actin was added,the proportion of GhXLIM6 in the precipitation was significantly higher than that of GhWLIM5 after high-speed centrifugation,indicating that the ability of GhWLIM5 to bind F-Actin was weaker than that of GhXLIM6.Fiber quality analysis showed that inhibition of GhWLIM5 expression also affected the secondary wall development of cotton fibers.However,real-time fluorescence quantitative analysis showed that the expression of these cellulose synthase genes-GhCESA4/7/8 in transgenic cotton fibers did not change significantly compared with the wild type,indicating that GhWLIM5 may not directly affect the secondary wall development of cotton fibers.Research findings revealed that GhWLIM5 played an important role in cotton fiber elongation by binding and maintaining dynamic F-Actin cytoskeleton.

关 键 词：陆地棉 纤维伸长生长 肌动蛋白细胞骨架 LIM蛋白 

分 类 号：S562[农业科学—作物学]