转录因子Dof3在玉米籽粒糊粉层发育中的功能与作用机制

玉米胚乳发育的调控一直是科学研究热点，糊粉层是玉米胚乳的重要组成部分。Dof蛋白是植物特有的转录因子，参与许多生理过程。通过对玉米进行全基因组的筛选，获得糊粉层中特异表达Dof转录因子基因Zmdof3，干扰Zmdof3在玉米籽粒中的表达，导致转基因玉米籽粒干瘪、胚发育不良、出现多层糊粉层细胞，原位杂交显示ZmDof3基因主要在籽粒的糊粉层中表达。这些结果暗示ZmDof3在玉米糊粉层发育中起着重要的作用。进一步，对干扰的转基因籽粒中与糊粉层发育相关基因的分析显示，Dek1基因的表达有所提高，推测ZmDof3可能在Dek1的上游起作用，通过负调控Dek1表达，调控糊粉层细胞的发育。本项目提出申请，进行深入研究，明确ZmDof3在玉米糊粉层发育中的作用和作用机制，探讨Zmdof3参与的玉米籽粒发育的调控网络。研究结果不仅能够加深对玉米籽粒糊粉层发育的了解，还能推进对植物Dof蛋白的功能研究。

Regulation of maize endosperm development has been the focus of scientific research. Aleurone is one of the most important components in maize endosperm. Dof proteins are members of plant-specific transcription factors and play significant roles in diverse biological processes. By genome-wide screening, we identified a Dof transcription factor, Zmdof3, which specifically expresses in maize endosperm. Suppression of ZmDof 3 by the RNAi resulted in disorganized aleurone, which locally contains multilayer cells. In situ hybridization experiments showed that Zmdof3 is mainly expressed in the aleurone of maize endosperm, suggesting that Zmdof3 contributes to the aleurone development. Furthermore, the expression pattern of aleurone-relative genes showed that Dek1, a central regulator required for aleurone cell fate specification, has increased expression level in Zmdof3-RNAi endosperm. These results implied that Zmdof3 may function as a negative regulator of Dek1 in the signaling system controlling aleurone development. In this project, we will reveal the mechanism and explore regulatory network of Zmdof3 in maize aleurone development by further study. The results will not only enrich our understanding of maize aleurone development, but also facilitate the functional research of Dof proteins.