水稻OsCBL10参与水淹胁迫下种子萌发的机理研究

With the global warming, waterlogging has become one of the most important reasons for causing the decline in the yield and quality of rice. To carry out an in-depth understanding on the molecular mechanism of rice in response to flooding stress and screening potential submergence tolerance genes in rice are able to enrich the molecular agronomy theory and gain great application potentials in agriculture. In our previous study, we performed the proteomics investigation on the two rice cultivars of flooding-tolerant (Low88) and flooding-intolerant (Up221) during the flooding stress and one of differentially expressed protein OsCBL10 was selected for further characterization on flooding responses. The gene expression of OsCBL10 was significantly higher in Up221 than in Low88 upon the flooding treatment. Meanwhile, transgenic plants overexpressing OsCBL10 showed flooding-intolerant compared with wild-type plants, suggesting that OsCBL10 may a negative role in the regulation of rice in response to flooding stress. Here, further functional dissection of OsCBL10 will be performed. On the one hand, combining with the physiological, biochemistry and molecular biology experiments, our results may reveal that OsCBL10 interact with CIPK proteins, thus controlling the calcium signaling for the regulation of flooding responses during the seed germination. On the other hand, the OsCBL10 mutant will be acquired by the CRISPR/Cas9 system, followed with the functional verification and proteomic analysis for further elucidate the molecular mechanism of OsCBL10 involved in the regulation of rice flooding response during the seed germination.

伴随着全球气候变暖，淹涝灾害已成为水稻产量和质量下降的主要原因之一。深入开展水稻应对水淹胁迫的分子机理研究以及挖掘潜在的水稻耐淹基因，对于丰富分子农业的理论与实践具有实用价值。我们前期研究通过对两种水稻耐淹型和不耐淹型在水淹胁迫下的蛋白组分析，筛选到OsCBL10蛋白在它们中差异表达，其基因也被证实水淹胁迫下在不耐淹型中的表达水平远远强于在耐淹型中。同时，过表达转基因植株在水淹胁迫下表现出不耐淹的表型，暗示着OsCBL10在水稻应对水淹胁迫时可能起到反向调节的作用。本课题将以OsCBL10蛋白为切入点，一方面利用生理、生化、分子生物学手段分析蛋白定位及其功能，揭示OsCBL10可能与CIPK蛋白相互作用通过调节钙离子流动或解码钙信号进而调控水淹胁迫下的种子萌发过程。另一方面，通过获得突变体进行功能验证和蛋白组学分析，进一步阐明OsCBL10参与调控水稻水淹胁迫下种子萌发过程的分子机制.

伴随着全球气候变暖，淹涝灾害已成为水稻产量和质量下降的主要原因之一。因此植物水淹领域的研究很有必要，但是目前大多研究因只侧重于转录层面或组学层面，水稻耐淹基因的挖掘与功能验证十分匮乏。本项目通过对两种水稻耐淹型和不耐淹型在水淹胁迫下的蛋白基因组学联合分析，筛选到一个水淹调控关键蛋白OsCBL10在它们中差异表达，其基因也被证实水淹胁迫下在不耐淹型中的表达水平远远强于在耐淹型中。后期发现OsCBL10的两种类型启动子区域通过影响OsCBL10的差异表达，调控水稻种子在水淹胁迫下的萌发，从而达到水稻水淹耐受型和不耐受型品种的分化。进一步的生理生化分析，我们发现含有OsCBL10中T-type启动子的水淹耐受型品种具备比较低的钙离子通量的变化和比较高的淀粉水解酶活性，而胚芽鞘的生长伸长与体内淀粉的水解过程密切相关，它是种子萌发过程中必不可少的能量源。因此，我们推测T-type启动子使OsCBL10维持在较低表达水平，从而影响上游钙通量的变化，导致增强了下游OsAMY3和OsCIPK15蛋白的协同响应。而OsAMY3基因和蛋白水平的升高，进一步促进了胚芽鞘的生长伸长，从而使这部分水稻品种具备耐淹的品质。综上所述本项目既促进了对CBL蛋白在逆境胁迫下的新认知，也丰富了潜在水稻耐淹基因的种类，为水稻耐淹种质资源多样化提供重要的理论基础，具有十分重要的科学意义和实践意义。项目中所用的蛋白基因组技术分析平台可以进一步扩大推广，用以快速筛选低氧萌发相关基因，为直播水稻栽培措施改良和抗低氧水稻品种选育提供前期理论基础。