微丝解聚因子ADF是调控微丝骨架动态的关键因子之一，在植物生长发育以及应答生物和非生物胁迫中具有重要功能。前期研究中, 我们发现棉花GhADF6基因的表达受大丽轮枝菌诱导，并且下调GhADF6基因的表达能够提高棉花对大丽轮枝菌侵染的耐受性。微丝染色发现，与对照相比，GhADF6表达水平降低棉花植株根部的束状微丝含量较高，推测可能与其抗病性提高相关。本课题拟以棉花-大丽轮枝菌为系统，通过生物化学、分子生物学和细胞生物学以及转基因等方法，分析GhADF6表达调控介导的微丝动态变化在棉花应答大丽轮枝菌侵染过程中的生理功能及其作用机制。相关的研究结果不仅可以为阐明微丝骨架在植物防御反应中的作用提供理论依据，也可以为利用分子育种方法提高棉花黄萎病抗性提供新思路。

Actin depolymerizing factor (ADF) is a key regulator in actin dynamics in eukaryotic cells, involved in numerous processes including growth and development, and in response to abiotic and biotic stresses. In the previous study, we found that expression of GhADF6 was markedly down-regulated when cotton plant was inoculated with the soil-born fungus Verticillium dahiliae, and down-regulating the expression of GhADF6 (VIGS-GhADF6) enhanced the tolerance to Verticillium wilt. The preliminary experiments showed that compared with the control plants, the actin filaments of VIGS-GhADF6 plants formed more and thicker bundles, which may account for the increased resistance to the fungi. Using biochemistry, cell biology and transgenic methods, we are going to investigate the regulated expression of GhADF6 and dynamic reorganizition of actin filaments in defense response using cotton-V. dahlia as a model system. Our study will provide experimental evidence for the functional mechanism of actin cytoskeleton in response to fungus invasion as well as a candidate gene for genetic improvement of the disease resistance against V. dahliae in cotton.