黄酮醇是一类主要的类黄酮化合物，在保卫细胞中含量较高，暗示其可能参与调控气孔运动，但至今未见相关报道。前期工作中，我们发现干旱胁迫下小麦保卫细胞中黄酮醇含量及黄酮醇合成酶基因TaFLS1转录水平明显提高，而且在小麦渐渗系抗旱新品种山融3号中的提高幅度较其亲本普通小麦更显著；TaFLS1过表达显著提高小麦和拟南芥保卫细胞中黄酮醇含量，干旱条件下通过提高H2O2水平来促进气孔关闭、增强抗旱性；黄酮醇通过JA信号通路调控气孔关闭。本项目拟在前期工作基础上，系统分析干旱等胁迫下TaFLS1响应及黄酮醇合成特征，分离和鉴定黄酮醇促进气孔关闭的关键因子，通过对SR3抗旱性的QTL定位，分析TaFLS1与SR3抗旱QTL的相关性，以期为阐明气孔运动调控新机制及SR3抗旱基础提供线索，为抗旱小麦等作物新品种培育提供优质基因源。

Flavonols strongly accumulate in guard cells, suggesting their participation in stomatal movement, but the suggestion has not been confirmed so far. In our previous work, both the flavonol content in guard cells and the transcription of flavonol synthase TaFLS1 were significantly increased in SR3, a wheat introgression cultivar SR3 with high drought tolerance, and its parent common wheat JN177, with a stronger increase in SR3. TaFLS1 overexpression in both wheat and Arabidopsis significantly improved the flavonol content in guard cells. Flavonol accumulation promoted stomatal closure by elevating H2O2 level in guard cells to enhance drought tolerance. The contribution of flavonols in stomatal closure was achieved through JA pathway. In this project, on the basis of previous work, we propose to analyze the drought responsive patterns of TaFLS1 transcription and flavonol synthesis, to isolate regulatory components mediating flavonols-modulated stomatal closure, to measure the association between TaFLS1 and drought tolerance QTLs of SR3 via localizing QTLs of SR3’s drought tolerance. This work would provide evidence for uncovering the novel mechanism governing stomatal movement and the basis of SR3’s drought tolerance, and provide excellent candidate gene for crop molecular breeding.