Ma Jianjiang, Yang Liupeng, Dang Yuanyue, Shahzad Kashif, Song Jikun, Jia Bing, Wang Li, Feng Juanjuan, Wang Nuohan, Pei Wenfeng, Wu Man, Zhang Xuexian, Zhang Jinfa, Wu Jianyong, Yu Jiwen
State Key Laboratory of Cotton Bio-breeding and Integrated Utilization, Institute of Cotton Research of the Chinese Academy of Agricultural Sciences, Anyang, China; Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou, China.
State Key Laboratory of Cotton Bio-breeding and Integrated Utilization, Institute of Cotton Research of the Chinese Academy of Agricultural Sciences, Anyang, China.
J Adv Res. 2025 Jul;73:1-14. doi: 10.1016/j.jare.2024.08.004. Epub 2024 Aug 4.
Interspecific introgression between Gossypium hirsutum and G. barbadense allows breeding cotton with outstanding fiber length (FL). However, the dynamic gene regulatory network of FL-related genes has not been characterized, and the functional mechanism through which the hub gene GhTUB5 mediates fiber elongation has yet to be determined.
Coexpression analyses of 277 developing fiber transcriptomes integrated with QTL mapping using 250 introgression lines of different FL phenotypes were conducted to identify genes related to fiber elongation. The function of GhTUB5 was determined by ectopic expression of two TUB5 alleles in Arabidopsis and knockout of GhTUB5 in upland cotton. Yeast two-hybrid, split-luciferase and pull-down assays were conducted to screen for interacting proteins, and upstream genes were identified by yeast one-hybrid, dual-LUC and electrophoretic mobility shift assays.
The 32,612, 30,837 and 30,277 genes expressed at 5, 10 and 15 days postanthesis (dpa) were grouped into 19 distinct coexpression modules, and 988 genes in the MEblack module were enriched in the cell wall process and exhibited significant associations with FL. A total of 20 FL-QTLs were identified, each explaining 3.34-16.04 % of the phenotypic variance in the FL. Furthermore, several FL-QTLs contained 15 genes that were differentially expressed in the MEblack module including the tubulin beta gene (TUB5). Compared with the wild type, the overexpression of GhTUB5 and GbTUB5 in Arabidopsis suppressed root cell length but promoted cellulose synthesis. Knockout of GhTUB5 resulted in longer fiber lines. Protein-based experiments revealed that GhTUB5 interacts with GhZFP6. Additionally, GhTUB5 was directly activated by GhHD-ZIP7, a homeobox-leucine zipper transcription factor, and its paralogous gene was previously reported to mediate fiber elongation.
This study opens a new avenue to dissect functional mechanism of cotton fiber elongation. Our findings provide some molecular details on how GhTUB5 mediates the FL phenotype in cotton.
陆地棉（Gossypium hirsutum）和海岛棉（G. barbadense）之间的种间基因渐渗使得培育出具有优异纤维长度（FL）的棉花成为可能。然而，与纤维长度相关基因的动态基因调控网络尚未得到表征，且枢纽基因GhTUB5介导纤维伸长的功能机制仍有待确定。
利用250个不同纤维长度表型的渐渗系，对277个发育中的纤维转录组进行共表达分析，并结合QTL定位，以鉴定与纤维伸长相关的基因。通过在拟南芥中异位表达两个TUB5等位基因以及敲除陆地棉中的GhTUB5来确定GhTUB5的功能。进行酵母双杂交、分裂荧光素酶和下拉试验以筛选相互作用蛋白，并通过酵母单杂交、双荧光素酶和电泳迁移率变动试验鉴定上游基因。
在开花后5、10和15天（dpa）表达的32,612、30,837和30,277个基因被分为19个不同的共表达模块，MEblack模块中的988个基因在细胞壁过程中富集，并与纤维长度表现出显著关联。总共鉴定出20个纤维长度QTL，每个QTL解释了纤维长度表型变异的3.34 - 16.04%。此外，几个纤维长度QTL包含15个在MEblack模块中差异表达的基因，包括微管蛋白β基因（TUB5）。与野生型相比，GhTUB5和GbTUB5在拟南芥中的过表达抑制了根细胞长度，但促进了纤维素合成。GhTUB5的敲除导致纤维更长的品系。基于蛋白质的实验表明，GhTUB5与GhZFP6相互作用。此外，GhTUB5被同源异型框 - 亮氨酸拉链转录因子GhHD - ZIP7直接激活，其同源基因先前已被报道介导纤维伸长。
本研究为剖析棉花纤维伸长的功能机制开辟了一条新途径。我们的研究结果提供了一些关于GhTUB5如何介导棉花纤维长度表型的分子细节。
Zotero 插件