孕穗期低温是水稻生产的主要限制性因子之一，克隆重要应用价值的孕穗期耐低温基因并培育耐逆水稻新品种具有重要意义。前期对203个栽培稻进行孕穗期低温筛选，利用全基因组关联分析（GWAS）获得一个低温相关基因OsbZIPX2。OsbZIPX2在孕穗期和开花授粉期受低温诱导，过表达OsbZIPX2不能提高水稻对低温的耐受性，RNAi却对低温敏感。酵母双杂表明OsbZIPX2与OsbZIPX1互作。过表达OsbZIPX2与过表达OsbZIPX1杂交株系显著提高了水稻对低温的耐受性。本申请拟结合遗传学、细胞生物学、分子生物学和生化等技术手段进一步明确OsbZIPX1和OsbZIPX2的互作；OsbZIPX2调控的下游靶基因；OsbZIPX1协同调控OsbZIPX2响应低温逆境胁迫的分子机制及其影响因素，包括对靶基因的结合及转录活性的影响；探讨OsbZIPX1和OsbZIPX2在水稻耐低温改良的有效途。

Low temperature is one of the major constraints in rice production. It is significant important that cloning tolerance to low temperature genes and cultivating new rice varieties resistant to abiotic stresses. We using a genome-wide association study (GWAS) in a population 203 cultivated rice varieties treated with low temperature during rice booting stage, and analysised each side of the peak SNPs, and identified a new loci associated gene with low temperature, OsbZIPX2. We found that OsbZIPX2 was quickly induced by low temperature during both booting stage and flowering stage. Transgenic plants analysis showed that OsbZIPX2 overexpressing had not improved rice tolerance to low temperature, but OsbZIPX2 RNAi transgenic plant showed sensitive to low temperature. Furthermore, we found that OsbZIPX2 can form heterodimer with OsbZIPX1 in yeast. Moreover, OsbZIPX1 overexpressing and OsbZIPX2 overexpressing hybrid lines have greatly increased rice tolerance to low temperature during reproductive stage. In this study, we would like to investigate conforming that OsbZIPX1 interact with OsbZIPX2; exploring OsbZIPX2 directly target genes and influence factors; the mechanism of OsbZIPX1 and OsbZIPX2 involved in abiotic stress response by using genetics, cellular biology, molecular biology, and biochemistry means, and also explore their possible application in rice low temperature tolerance improvement.