College of Agronomy, Northwest Agriculture and Forestry University, Yangling 712100, China.
State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang 455000, China.
Int J Mol Sci. 2020 Jul 19;21(14):5095. doi: 10.3390/ijms21145095.
Young cotyledons of cotton seedlings are most susceptible to chilling stress. To gain insight into the potential mechanism of cold tolerance of young cotton cotyledons, we conducted physiological and comparative transcriptome analysis of two varieties with contrasting phenotypes. The evaluation of chilling injury of young cotyledons among 74 cotton varieties revealed that H559 was the most tolerant and YM21 was the most sensitive. The physiological analysis found that the ROS scavenging ability was lower, and cell membrane damage was more severe in the cotyledons of YM21 than that of H559 under chilling stress. RNA-seq analysis identified a total of 44,998 expressed genes and 19,982 differentially expressed genes (DEGs) in young cotyledons of the two varieties under chilling stress. Weighted gene coexpression network analysis (WGCNA) of all DEGs revealed four significant modules with close correlation with specific samples. The GO-term enrichment analysis found that lots of genes in H559-specific modules were involved in plant resistance to abiotic stress. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that pathways such as plant hormone signal transduction, MAPK signaling, and plant-pathogen interaction were related to chilling stress response. A total of 574 transcription factors and 936 hub genes in these modules were identified. Twenty hub genes were selected for qRT-PCR verification, revealing the reliability and accuracy of transcriptome data. These findings will lay a foundation for future research on the molecular mechanism of cold tolerance in cotyledons of cotton.
棉花幼苗的子叶对冷胁迫最为敏感。为了深入了解棉花幼苗耐寒的潜在机制，我们对两个表型差异较大的品种进行了生理和比较转录组分析。在 74 个棉花品种中评估了幼嫩子叶的冷害，结果表明 H559 最具耐冷性，YM21 最敏感。在冷胁迫下，YM21 的子叶中 ROS 清除能力较低，细胞膜损伤比 H559 更为严重。RNA-seq 分析在两个品种的幼嫩子叶中总共鉴定出 44998 个表达基因和 19982 个差异表达基因（DEGs）。对所有 DEGs 的加权基因共表达网络分析（WGCNA）显示，四个显著模块与特定样本密切相关。GO-term 富集分析发现，H559 特异性模块中的许多基因参与了植物对非生物胁迫的抗性。京都基因与基因组百科全书（KEGG）通路分析表明，植物激素信号转导、MAPK 信号通路和植物-病原体相互作用等途径与冷胁迫反应有关。这些模块中鉴定出了 574 个转录因子和 936 个枢纽基因。选择了 20 个枢纽基因进行 qRT-PCR 验证，显示了转录组数据的可靠性和准确性。这些发现将为棉花子叶耐寒性的分子机制研究奠定基础。
