高温胁迫下棉花苗期的生理响应和转录组分析

Physiological response and transcriptome analysis of cotton in the six-leaf period under high temperature

以棉花品系CN01和源23(耐高温)为材料,研究高温处理对6叶1心期棉花茎尖的影响。测定了25℃(CK)和40℃(高温)处理0、2、6、10、14、24 h后超氧化物歧化酶(SOD)活性、过氧化物酶(POD)活性、H2O2含量的变化。结果表明,与25℃相比,40℃处理6 h后CN01、源23中SOD活性的增加幅度大,且源23中SOD活性的增加幅度小于CN01。与25℃相比,CN01和源23中POD的活性分别在40℃处理后14 h和10 h后出现了明显的下降,且源23中POD活性的下降幅度小于CN01。与25℃相比,40℃处理6 h后CN01中H2O2含量的增加幅度要高于源23。综合上述3个指标发现,40℃处理6 h棉花茎尖的生理指标变化最明显。对40℃处理6 h的6叶1心期棉花茎尖进行了RNA-seq研究,发现与25℃相比,40℃处理后CN01中差异表达的与小热激蛋白(sHSP)相关的基因为23个,在源23中差异表达的基因为3个。qRT-PCR结果显示与对照相比,高温处理后与s HSP相关的基因HS22C在CN01和源23中分别上调7.29和7.42倍。

The effects of high temperature treatment on the stem tips of cotton in six-leaf period were studied by using‘CN01’and‘Yuan 23’(a high temperature resistant cotton).Firstly,We separately measured the changes of superoxide dismutase(SOD)activity,peroxidase(POD)activity,and H2O2 content after treatment at 25℃(CK)and 40℃(high temperature treatment)for 0 h,2 h,6 h,10 h,14 h,and 24 h.It was found that the rate of SOD activity increase in’CN01’and’Yuan 23’was the largest after 6 h treatment at 40℃compared with 25℃,and the increase of SOD activity in’CN01’was greater than Yuan 23’.The activity of POD in’CN01’and’Yuan 23’showed a significant decrease after 14 h and 10 h after high temperature treatment at 40℃,respectively,the decrease of POD activity in’Yuan 23’was less than’CN01’.Compared with25℃,the increase of H2O2 content in’CN01’was higher than’Yuan 23’after 6 h treatment at 40℃.Transcriptome analysis of cotton stem tips in six-leaf period treated with high temperature stress for 6 hours showed that there were 23 genes associated with small heat shock protein(s HSP)differentially expressed in’CN01’after treatment at 40℃,and 3 genes differentially expressed in’Yuan 23’,compared with 25℃.The qRT-PCR results showed that the HS22 C gene associated with sHSP after high temperature treatment was up-regulated by 7.29 and 7.42 folds in’CN01’and’Yuan 23’,respectively,compared with control.