拟南芥生殖型ADF的功能及其自身活性调控机制的研究

花粉作为高等植物的雄配子体，其萌发及后续的花粉管生长是植物有性生殖过程的关键步骤。研究表明微丝骨架在这个过程中扮演了非常重要的调控作用，阐明其动态组装调节机制对于理解花粉管生长调控机制以及对其进行遗传学操作具有重要的科学理论意义。我们通过对花粉特异表达的拟南芥微丝解聚因子7（actin-depolymerizing factor7; AtADF7）的研究发现其介导微丝切割参与调控花粉管槽部微丝束的动态解聚以及花粉管的极性生长，但ADF7如何与另一个花粉特异表达的ADF异构体（AtADF10）协作调控花粉管微丝动态组装以及他们自身的活性调控并不清楚。本项目拟对花粉管中ADF异构体的功能协作及他们自身的活性调控方式（重点观察磷酸化/去磷酸化调控方式）进行研究。该研究将加深人们理解ADF家族蛋白的功能和作用机制以及微丝骨架调控花粉管极性生长的作用机制。

Pollen, as the male gametophyte in higher plants, its germination and the subsequent tube growth is a key step during flowering plant reproduction. Previous studies showed that the actin cytoskeleton is a key regulator during this process. Elucidation of the regulatory mechanism underlying the dynamic assembly of the actin cytoskeleton promises to enhance our understanding of the molecular mechanism underlying pollen tube growth and allow people to genetically manipulate plant reproduction. Our previous studies found that actin-depolymerizing factor (ADF) regulates the dynamic turnover of actin cables and polarized pollen tube growth via severing actin filaments through studying the pollen specifically expressed AtADF7. However, how AtADF7 coordinates with another pollen expressed ADF, AtADF10, to regulate actin dynamics as well as how their activities are regulated remains largely unknown. This project aims to dissect the coordination of those two ADF isovariants and the regulatory mode of their activities. In particular, we will emphasize on how their activity is regulated by phosphorylation and dephosphorylation. This study promises to enrich our knowledge regarding the functions and mode of action of ADF family members as well as the function and mechanism of action of the actin cytoskeleton during pollen tube growth in general.