玉米突变体caspl2b2的耐盐特性评价及转录组分析

Salt tolerance evaluation and transcriptome analysis of maize mutant caspl2b2

盐胁迫敏感突变体是研究作物耐盐遗传基础和分子机制的重要遗传材料。本研究以自交系LY8405和突变体caspl2b2为材料,开展正常生长、盐胁迫条件下苗期表型鉴定和生理生化指标测定分析。结果表明,与LY8405相比,盐胁迫下caspl2b2存活率显著降低,地上部分生长显著受到抑制;地上部Na+离子含量显著升高,丙二醛(MDA)含量显著升高;蒸腾速率、气孔导度及胞间CO_(2)浓度显著升高,净光合速率显著下降。为揭示其盐胁迫下表型差异的分子基础,对LY8405和caspl2b2突变体材料在正常生长和盐胁迫条件下叶片组织进行转录组分析。结果表明,差异表达基因主要富集到谷胱甘肽转移酶活性、谷胱甘肽代谢过程、氧化还原酶活性和细胞稳态等相关途径,其中谷胱甘肽代谢过程最为显著。本研究不仅为作物耐盐遗传基础解析提供了重要的种质资源,也为耐盐基因的挖掘及其遗传调控网络分析奠定了基础。

Salt stress-sensitive mutants are crucial genetic materials for studying the genetic basis and molecular mechanisms of salt tolerance in crops.In this study,the maize inbred line LY8405 and the mutant caspl2b2 were used to investigate phenotype,physiological,and biochemical indices at the seedling stage under normal growth and salt stress conditions.The results showed that,compared to LY8405,the survival rate of caspl2b2 significantly decreased under salt stress,and the growth of aboveground parts was notably inhibited.The content of Na+ions and malondialdehyde(MDA)in aboveground parts significantly increased,while transpiration rate,stomatal conductance,and intercellular CO2 concentration also increased significantly.Conversely,the net photosynthetic rate significantly decreased.To uncover the molecular basis of the phenotypic differences under salt stress,transcriptome analysis was performed on leaf tissues of LY8405 and caspl2b2 under normal growth and salt stress conditions.The results revealed that differentially expressed genes(DEGs)were mainly concentrated in glutathione transferase activity,glu-tathione metabolism,REDOX enzyme activity,and cell homeostasis,with glutathione metabolism being the most significant.This study not only provides important germplasm resources for the genetic basis analysis of crop salt tolerance,but also lays a foun-dation for the identification of salt tolerance genes and the analysis of genetic regulatory networks.