棉花GhSEDEG38基因调控棉花耐盐性的功能分析
Functional analyses of cotton salt tolerance regulated by GhSEDEG38 gene in cotton

基于棉花体细胞胚胎再生不同时期表达谱中筛选出一系列差异表达转录因子，通过RT PCR和qRT PCR分析这些转录因子在不同逆境处理下的表达，发现GhSEDEG38基因（somatic embryogenesis differencially expressed gene 38 ）的表达受盐胁迫诱导明显上调；序列分析发现GhSEDEG38编码bZIP型转录因子，与拟南芥bZIP53基因同源。为进一步验证该基因的功能，构建了该基因的RNAi干涉载体并转化棉花，通过分子检测获得了表达量显著降低的转基因棉花株系。通过对萌发期和三叶期转基因材料和对照材料进行盐处理发现，干涉GhSEDEG38基因降低棉花在萌发期及苗期对盐胁迫的抗性，盐处理后转基因植株的MDA含量和活性氧含量显著高于对照材料，而可溶性糖含量显著低于对照材料。综上，GhSEDEG38参与棉花对盐胁迫的应答。
A series of differentially expressed transcription factors were selected from the expression profiles of somatic embryos at different stages of cotton regeneration.The expression of GhSEDEG38 (somatic embryogenesis differentially expression gene 38) was significantly up regulated by salt stress by analyzing the expression of these transcription factors under different stress treatments with RT-PCR and qRT-PCR.Sequence analyses revealed that GhSEDEG38 encodes a bZIP type transcription factor that is homologous to the ArabidopsisbZIP53 gene.In order to further verify the function of the gene,RNAi interference vectors of this gene were constructed and transformed into cotton,and transgenic cotton lines with significantly reduced expression levels were obtained through molecular detection.We compared the growth index and physical parameters between RNAi and control lines under salt treatments.The results showed that the down regulated expression of GhSEDEG38 reduced the resistance of cotton to salt stress during seed germination and early seedling stage.The MDA content and reactive oxygen species in transgenic plants was significantly higher than those in the control line,while the soluble sugar content was significantly lower than that in the control line.It is indicated thatGhSEDEG38 might be involved in the response to salt stress in cotton.