水稻灌浆是胚乳中淀粉及蛋白质合成和积累的过程，直接决定着水稻的产量和品质，但其分子机理很不清楚。我们前期鉴定了一份灌浆慢、高垩白的突变体dgf1(defective grain filling 1)。基因定位和互补结果表明dgf1表型由一个MATE转运蛋白提前终止所致。初步功能分析表明：DGF1蛋白位于细胞膜具有外排ABA活性，且DGF1序列存在籼粳分化，含DGF1片段的9311/Nip代换系表现垩白增加。在此基础上，结合遗传学、分子生物学和生理生化等方法开展DGF1在颖果中的分子生物学功能研究，揭示DGF1通过控制ABA转运参与水稻灌浆的分子生物学功能，以及参与DGF1调控网络的重要因子，为全面解析水稻灌浆的分子调控网络奠定基础。另一方面，利用9311/Nip片段代换系研究DGF1籼粳型功能差异，阐明DGF1在水稻籼粳分化过程生物学功能差异，为提高水稻产量和品质提供优异基因资源和理论依据

Rice grain filling is a process of the synthesis and accumulation of starch and protein, which directly determines rice yield and quality. Our preliminary study identified a mutant, dgf1, with slow grain-filling rate and high chalkiness degree. Gene mapping and complementary results showed that the phenotype of the dgf1 mutant was caused by a premature stop code in a MATE transporter. DGF1 protein was localized on plasma membrane, and transport ABA. Indica-Japonica differentiation was observed in DGF1 locus, and the 9311/Nip SSSLs including DGF1 locus showed high chalkness. Based on these preliminary data, we use the approaches of genetics, molecular biology, physiology and biochemistry to study: the molecular biological function regulated by DGF1 in caryopsis, and the important regulators involved in the pathway that DGF1 regulated. These results will lay a foundation for understanding the molecular network of grain filling in rice. On the other hand, we use 9311/Nip SSSLs to study the difference of biological function between Japonica and Indica haplotype. These results will reveal the biological function of different DGF1 haplotypes during rice differentiation, also provide elite gene resource and theoretical basis for improving rice yield and quality.