Table3_Genome-wide identification and expression analysis of glutathione S-transferase gene family to reveal their role in cold stress response in cucumber.XLSX

The plant glutathione S-transferases (GSTs) are versatile proteins encoded by several genes and play vital roles in responding to various physiological processes. Members of plant GSTs have been identified in several species, but few studies on cucumber (Cucumis sativus L.) have been reported. In this study, we identified 46 GST genes, which were divided into 11 classes. Chromosomal location and genome mapping revealed that cucumber GSTs (CsGSTs) were unevenly distributed in seven chromosomes, and the syntenic regions differed in each chromosome. The conserved motifs and gene structure of CsGSTs were analyzed using MEME and GSDS 2.0 online tools, respectively. Transcriptome and RT-qPCR analysis revealed that most CsGST members responded to cold stress. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses for differentially expressed CsGSTs under cold stress revealed that these genes responded to cold stress probably through “glutathione metabolism.” Finally, we screened seven candidates that may be involved in cold stress using Venn analysis, and their promoters were analyzed using PlantCARE and New PLACE tools to predict the factors regulating these genes. Antioxidant enzyme activities were increased under cold stress conditions, which conferred tolerance against cold stress. Our study illustrates the characteristics and functions of CsGST genes, especially in responding to cold stress in cucumber.

植物谷胱甘肽转移酶（GSTs）是一类由多个基因编码的多功能蛋白，在应对多种生理过程中发挥着至关重要的作用。植物GSTs成员已在多个物种中被鉴定出来，然而关于黄瓜（Cucumis sativus L.）的研究却相对较少。在本研究中，我们鉴定了46个GST基因，并将其划分为11个类别。通过对染色体的定位和基因组图谱分析，发现黄瓜GSTs（CsGSTs）在七个染色体上的分布不均，且每个染色体的同源区域存在差异。利用MEME和GSDS 2.0在线工具分别分析了CsGSTs的保守基序和基因结构。转录组学和实时定量PCR分析表明，大多数CsGST成员对冷胁迫作出反应。对冷胁迫下差异表达CsGSTs的基因本体学（GO）和京都基因与基因组百科全书（KEGG）通路富集分析显示，这些基因可能通过“谷胱甘肽代谢”途径应对冷胁迫。最终，我们通过Venn分析筛选出七个可能参与冷胁迫的候选基因，并利用PlantCARE和新PLACE工具分析其启动子，以预测调节这些基因的因素。在冷胁迫条件下，抗氧化酶活性增加，赋予了植物对冷胁迫的耐受性。本研究揭示了CsGST基因的特征及其功能，尤其是在黄瓜应对冷胁迫方面的作用。