水稻GNPP2基因参与穗粒数调控的分子机制研究

每穗粒数是影响水稻产量的重要农艺性状，但作为复杂的数量性状，其分子遗传机制尚知之甚少。本项目前期通过全基因组关联分析挖掘了水稻中参与每穗粒数调控的相关位点。综合基因功能注释、基因表达分析和染色体片段置换系验证，我们发现了一个新的水稻穗粒数调控候选基因GNPP2。此外，我们的遗传转化实验结果初步表明GNPP2过表达负调控水稻每穗粒数。在本项目中，我们将借助基因编辑、过表达等遗传转化实验进一步验证GNPP2的基因功能，利用转录组分析和互作蛋白筛选等探索GNPP2调控每穗粒数的分子机理，利用重测序数据分析GNPP2基因在自然群体中的关键遗传变异和筛选其优异单倍体型，最终以期为水稻穗形改良和分子设计育种提供基因资源和理论基础。

Grain number per panicle (GNPP) is an important agronomic trait for rice yield improvement. However, as a complex quantitative trait, the molecular and genetic mechanisms underlying GNPP remain largely unknown. In the early stage of this project, several loci related to GNPP were identified by genome-wide association analysis. Based on gene annotations, transcript profiles, and the experimental verification using the chromosome segment substitution lines, we found a new candidate gene GNPP2 for regulating grain number in rice. Besides, our genetic transformation experiments preliminarily indicated that GNPP2 overexpression negatively regulated GNPP in rice. In this project, to provide genetic resources and a theoretical basis for panicle improvement and molecular design breeding of rice, we will further validate the function of GNPP2 via genetic transformation experiments including gene editing and overexpression. Furthermore, its molecular mechanism will be dissected through RNA-seq, interaction protein screening, and so on. Finally, the key genetic variations of GNPP2 in natural populations will be explored using the re-sequencing data, and the excellent haplotypes will be further screened.