低温胁迫下两叶一心期棉花叶片的生理响应和转录组分析

Physiological response and transcriptome analysis of cotton leaf in the two-leaf period under low temperature

以CN01和SJB016(耐低温)为材料,研究了低温处理对两叶一心期棉花叶片的影响。测定了25℃(CK)和12℃(低温)处理0、3、6、12、24、48和72 h后CN01和SJB016中丙二醛(MDA)、可溶性糖(SS)和脯氨酸(Pro)含量的变化。研究发现,与25℃相比,12℃处理后CN01和SJB016中MDA、SS和Pro含量均上升。与CN01相比,低温处理后SJB016中MDA含量上升幅度较小,SS含量上升幅度较大,而Pro含量上升幅度较小。结合上述3个指标,发现12℃处理6 h棉花叶片的生理指标变化最明显。对12℃处理6h的两叶一心期棉花叶片进行了RNA-seq。结果表明,与25℃相比,12℃处理后与光合作用相关的基因在CN01中均表现为上调,而光系统Ⅱ放氧复合物(PsdP、PsdQ)等基因在SJB016中表现为下调。与植物激素相关差异的基因在CN01和SJB016中表现为上调基因多于下调基因,其中乙烯响应转录因子ERF053、ERF020、ERF061表现为显著上调。这些基因可能对提高棉花的抗寒性有重要作用。

CN01 and SJB016(a low temperature resistant cotton)were used as materials to study the effects of low temperature treat⁃ment on cotton in the two-leaf period.Firstly,We separately measured the contents of malondialdehyde(MDA),soluble sugar(SS)and proline(Pro)in CN01 and SJB016 at 25℃(CK)and 12℃(low temperature treatment)for 0,3,6,12,24,48 and 72 h.It was found that the contents of MDA,SS,and Pro in CN01 and SJB016 increased after 12℃treatment compared with 25℃.After low temperature treatment,the content of MDA in SJB016 increased less than CN01,the content of SS in SJB016 increased larger than CN01,and the content of Pro in SJB016 increased less than CN01.Transcriptome analysis of cotton leaves in two-leaf period after low temperature treatment for 6 hours showed that the photosynthesis-related genes were up-regulated in CN01 after 12℃treatment,while the genes of photosystem II oxygen-releasing complexes(PsdP,PsdQ,et al)were down-regulated in SJB016,compared with 25℃.The up-regulated differentially expressed genes associated with phytohormone were more than down-regulated genes in CN01 and SJB016,and ethylene-responsive transcription factors ERF053,ERF020,and ERF061 significantly up-regulated.These genes are deemed to play an important role in improving the cold resistance of cotton.