Wang Dan, Liu Zhuo, Xiao Yinghui, Liu Xionglun, Chen Yue, Zhang Zhuo, Kang Houxiang, Wang Xuli, Jiang Su, Peng Shasha, Tan Xinqiu, Zhang Deyong, Liu Yong, Wang Guo-Liang, Li Chenggang
College of Agronomy, Hunan Agricultural University, Changsha, 410128, Hunan, China.
State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.
Rice (N Y). 2021 Nov 26;14(1):98. doi: 10.1186/s12284-021-00538-0.
Cold tolerance at the bud burst stage (CTB) is a key trait for direct-seeded rice. Although quantitative trait loci (QTL) affecting CTB in rice have been mapped using traditional linkage mapping and genome-wide association study (GWAS) methods, the underlying genes remain unknown. In this study, we evaluated the CTB phenotype of 339 cultivars in the Rice Diversity Panel II (RDP II) collection. GWAS identified four QTLs associated with CTB (qCTBs), distributed on chromosomes 1-3. Among them, qCTB-1-1 overlaps with Osa-miR319b, a known cold tolerance micro RNA gene. The other three qCTBs have not been reported. In addition, we characterised the candidate gene OsRab11C1 for qCTB-1-2 that encodes a Rab protein belonging to the small GTP-binding protein family. Overexpression of OsRab11C1 significantly reduced CTB, while gene knockout elevated CTB as well as cold tolerance at the seedling stage, suggesting that OsRab11C1 negatively regulates rice cold tolerance. Molecular analysis revealed that OsRab11C1 modulates cold tolerance by suppressing the abscisic acid signalling pathway and proline biosynthesis. Using RDP II and GWAS, we identified four qCTBs that are involved in CTB and determined the function of the candidate gene OsRab11C1 in cold tolerance. Our results demonstrate that OsRab11C1 is a negative regulator of cold tolerance and knocking out of the gene by genome-editing may provide enhanced cold tolerance in rice.
芽期耐冷性（CTB）是直播水稻的一个关键性状。尽管已使用传统连锁作图和全基因组关联研究（GWAS）方法对影响水稻CTB的数量性状基因座（QTL）进行了定位，但潜在基因仍不清楚。在本研究中，我们评估了水稻多样性面板II（RDP II）中339个品种的CTB表型。GWAS鉴定出4个与CTB相关的QTL（qCTB），分布在第1至3号染色体上。其中，qCTB - 1 - 1与已知的耐冷微RNA基因Osa - miR319b重叠。另外3个qCTB尚未见报道。此外，我们对qCTB - 1 - 2的候选基因OsRab11C1进行了表征，该基因编码一种属于小GTP结合蛋白家族的Rab蛋白。OsRab11C1的过表达显著降低了CTB，而基因敲除则提高了CTB以及幼苗期的耐冷性，这表明OsRab11C1负向调控水稻的耐冷性。分子分析表明，OsRab11C1通过抑制脱落酸信号通路和脯氨酸生物合成来调节耐冷性。利用RDP II和GWAS，我们鉴定出4个参与CTB的qCTB，并确定了候选基因OsRab11C1在耐冷性中的功能。我们的结果表明，OsRab11C1是耐冷性的负调控因子，通过基因组编辑敲除该基因可能会提高水稻的耐冷性。
