种子休眠性是植物生命活动的一个重要生理阶段。对农业生产来说，种子休眠是一把双刃剑。种子休眠性减弱甚至丧失将造成作物穗发芽并降低其产量与品质；而种子休眠性过强则会导致种子不能萌发或者出苗参差不齐，影响生产进程。因此，深入研究种子休眠的分子生理机理，培育适度休眠的水稻品种，对保障我国粮食安全具有十分重要的意义。在前期的研究中，申请人辐射诱变获得水稻种子休眠突变体vha-A1，其主要特征种子萌发孔存在缺陷，对O2及ABA敏感。利用图位克隆技术证实VHA-A1就是控制突变体vha-A1种子休眠特性的基因，该基因编码液泡H+-ATPase A1亚基。本项目将在前期的研究基础上，研究VHA-A1调控水稻种子生长发育的细胞生物学特点，VHA-A1调控水稻种子休眠的代谢生理与分子调控网络，以及VHA-A1的磷酸化位点及其激酶，从细胞、生理和分子角度揭示VHA-A1控制水稻种子休眠的生理机理及分子调控网络。

Seed dormancy is an important physiological stage for plant life cycle and a double-edged sword for crop production. Loss or reduced seed dormancy is the key aspect directly related to pre-harvest sprouting which leads to loss of crop grain weight and quality. However, strong dormant seeds germinate unevenly or not at all，which will affect the progress of crop production. Thus, it is very important to study molecular and physiological mechanism of seed dormancy and develop the moderately dormant rice varieties for protection of food security in China. In our previous studies, the vha-A1 mutant was identified by 60Co γ-radiation treatment of indica restore N142, which showed seed dormancy attributable to physical (defect of micropyle structure) and physiological (ABA sensitivity) factors. Genetic analysis indicated that vha-A1 was controlled by a recessive nuclear gene, which was finely mapped to a 42 kb interval between two markers RM20540 and RM20542 on long arm of chromosome 6. Sequence analyses revealed a 1-bp deletion of C in the open reading frame (ORF) region of the vha-A1 gene (LOC_Os06g45120), which is predicted to encode vacuoler H+-ATPase subunit A1. The cloned gene was confirmed by genetic complementary test. In this study, in order to confirm VHA-A1 is very important for seed dormancy, we will investigate the relationship among the vacuolar H+-ATPase subunit A1 on rice seed development, especially the development of micropyle structure; Physiology of metabolism and molecular regulation network of VHA-A1 gene on rice seed dormancy; The phosphorylation sites of VHA-A1 and the kinase for its phosphorylation. Based on the results of above, the physiological mechanism and molecular regulation network of VHA-A1 on seed dormancy will be involved in rice.