DPC浸种诱导ABA调控棉花种子抗氧化能力的耐盐机制

缩节胺（DPC）是棉花上广泛使用的生长调节剂，为赤霉素合成抑制剂。我们前期研究表明DPC浸种促进盐胁迫下种子的萌发，且在耐盐性不同的材料间的调控效果存在差异，其调控机制待进一步研究。前期试验发现DPC浸种对盐胁迫种子中的ABA含量影响较大，转录组分析结果表明DPC显著调控了ABA代谢和ABA信号途径中的关键基因，且对活性氧代谢的关键基因Rboh表达影响较大。DPC浸种提高种子耐盐能力可能与ABA和抗氧化能力有关。在此基础上，本项目拟用前期筛选的耐盐性差异棉花材料CZ91和Z571，研究DPC浸种对盐胁迫下种子中ABA、ROS含量、ABA和ROS代谢及ABA信号途径中关键基因表达的影响，并结合蛋白质组学及外源ABA和氟啶酮添加试验，明确DPC浸种对棉花种子萌发期盐性的调节作用是否是通过诱导ABA调控抗氧化能力实现的。研究结果能进一步完善DPC浸种调控种子萌发期耐盐机制。

DPC, a gibberellic acid inhibitor, is a plant growth regulator widely used in cotton (Gossypium hirsutum L.). DPC-presoaking can improve the salt tolerance of cotton during seed germination, but there are differences among different genotypes, and its regulation mechanism needs further study. Our preliminary test showed that DPC had a great effect on ABA content in seeds under salt stress. The results of transcriptome analysis showed that DPC significantly regulated the key genes of ABA metabolism and ABA signaling pathway, and had a great influence on the expression of RbOH, the key gene of active oxygen metabolism. The improvement of salt tolerance by DPC-presoaking may be related to ABA and antioxidant capacity. On this basis, two cotton genotypes CZ91 and Z571 with different salt tolerance were selected to study the effects of DPC-presoaking on ABA, ROS content, ABA and ROS metabolism and key gene expression in ABA signal pathway under salt stress. Further combining with the proteomic study and the experiment of exogenous ABA and Fluridone addition, to make it clear whether DPC-presoaking improves the salt tolerance of cotton seeds during germination by inducing ABA to regulate the antioxidant capacity. The results can further improve the mechanism of DPC-presoaking regulating salt tolerance during seed germination.