Wang Hai-Yun, Wang Juan, Gao Peng, Jiao Gai-Li, Zhao Pi-Ming, Li Yan, Wang Gui-Ling, Xia Gui-Xian
National Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.
Plant Biotechnol J. 2009 Jan;7(1):13-23. doi: 10.1111/j.1467-7652.2008.00367.x. Epub 2008 Aug 26.
Cotton fibre is the most important natural fibres for textile industry. To date, the mechanism that governs the development of fibre traits is largely unknown. In this study, we have characterized the function of a member of the actin depolymerizing factor (ADF) family in Gossypium hirsutum by down-regulation of the gene (designated as GhADF1) expression in the transgenic cotton plants. We observed that both the fibre length and strength of the GhADF1-underexpressing plants increased as compared to the wild-type fibre, and transgenic fibres contained more abundant F-actin filaments in the cortical region of the cells. Moreover, the secondary cell wall of the transgenic fibre appeared thicker and the cellulose content was higher than that of the control fibre. Our results suggest that organization of actin cytoskeleton regulated by actin-associated proteins such as GhADF1 plays a critical role in the processes of elongation and secondary cell wall formation during fibre development. Additionally, our study provided a candidate intrinsic gene for the improvement of fibre traits via genetic engineering.
棉花纤维是纺织工业中最重要的天然纤维。迄今为止，调控纤维性状发育的机制在很大程度上尚不清楚。在本研究中，我们通过下调转基因棉花植株中一个肌动蛋白解聚因子（ADF）家族成员基因（命名为GhADF1）的表达，对其功能进行了表征。我们观察到，与野生型纤维相比，GhADF1表达下调植株的纤维长度和强度均有所增加，并且转基因纤维在细胞皮层区域含有更丰富的F-肌动蛋白丝。此外，转基因纤维的次生细胞壁看起来更厚，纤维素含量高于对照纤维。我们的结果表明，由诸如GhADF1等肌动蛋白相关蛋白调控的肌动蛋白细胞骨架组织在纤维发育过程中的伸长和次生细胞壁形成过程中起关键作用。此外，我们的研究为通过基因工程改善纤维性状提供了一个候选内在基因。
