我国农业生产劳动力日渐短缺，玉米收获机械化成为必然趋势，而玉米收获时籽粒含水量高是限制机械化粒收的主要因素。本研究以660份自交系的单位质量脱水速率作为表型数据进行全基因组关联分析，定位到一个编码RING型E3泛素蛋白连接酶的基因ZmGDR1，该基因主要在籽粒种皮部位表达且在籽粒脱水速率不同的自交系中的表达水平存在显著差异。本项目将在现有研究基础上，开展以下研究：1）通过对该基因不同转基因材料（敲除突变体及过表达）籽粒中水分含量的测定，明确该基因对籽粒水分含量和脱水速率的影响；2）通过泛素化实验和该基因互作蛋白的鉴定，解析其作为泛素连接酶影响籽粒脱水的作用机理；3）通过对不同转基因材料籽粒中内源激素ABA含量测定和ZmGDR1对ABA合成过程关键酶的蛋白稳定性的影响，明确该基因通过ABA途径调控籽粒脱水的机制。阐明该基因在调控籽粒脱水过程中的分子机制旨在为玉米籽粒性状的遗传改良奠定基础。

With the shortage of agricultural labor force in China, maize harvesting mechanization has become an inevitable trend. In this study, the unit mass dehydration rate of 660 inbred lines was used as the phenotypic data for genome-wide association analysis, and a gene encoding RING domain E3 ubiquitin ligases was located, which was mainly expressed in the seed coat and showed significant differences in transcription levels in inbred lines with different grain dehydration rates. Based on the existing research, this project will mainly carry out the following studies: 1) Determine the effect of this gene on the water content and dehydration rate of maize grains by obtain the water content in grains of different transgenic materials (gene knockout mutants and overexpression transgenic materials); 2) To explore the mechanism of ZmGDR1 as a ubiquitin ligase affecting grain dehydration through the ubiquitination experiment and the identification of ZmGDR1 interaction protein; 3) To identify the mechanism of the interaction between ZmGDR1 and ABA in the regulation of grain dehydration through the determination of the endogenous hormone ABA in the grains of different transgenic materials and the effect of ZmGDR1 on the protein stability of the key enzyme in the process of ABA synthesis. The functional analysis of ZmGDR1 gene in the regulation of grain dehydration will shed light on the genetic improvement of maize grain.