RESULTS: The transcriptome results showed that a total of 6,893 differentially expressed genes (DEGs) were discovered under submergence stress. Gene Ontology (GO) enrichment analysis showed that DEGs were involved in various stress or stimulus responses. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicated that DEGs related to plant hormone signal transduction, starch and sucrose metabolism, glycolysis and the biosynthesis of secondary metabolites were regulated by submergence stress. Eight DEGs related to ethylene signaling and 3 ethylene synthesis genes were identified in the hormone signal transduction. For respiratory metabolism, alcohol dehydrogenase (ADH, GH_A02G0728) and pyruvate decarboxylase (PDC, GH_D09G1778) were significantly upregulated but 6-phosphofructokinase (PFK, GH_D05G0280), phosphoglycerate kinase (PGK, GH_A01G0945 and GH_D01G0967) and sucrose synthase genes (SUS, GH_A06G0873 and GH_D06G0851) were significantly downregulated in the submergence treatment. Terpene biosynthetic pathway-related genes in the secondary metabolites were regulated in submergence stress.
CONCLUSIONS: Regulation of terpene biosynthesis by respiratory metabolism may play a role in enhancing the tolerance of cotton to submergence under flooding. Our findings showed that the mevalonate pathway, which occurs in the cytoplasm of the terpenoid backbone biosynthesis pathway (ko00900), may be the main response to submergence stress.
结果:转录组结果表明,在淹没胁迫下,总共发现了6,893个差异表达基因(DEGs)。基因本体论(GO)富集分析表明,DEG参与各种应激或刺激反应。京都基因和基因组百科全书(KEGG)通路分析表明,DEGs与植物激素信号转导有关,淀粉和蔗糖代谢,淹没胁迫调节糖酵解和次生代谢产物的生物合成。在激素信号转导中鉴定了8个与乙烯信号相关的DEGs和3个乙烯合成基因。对于呼吸代谢,乙醇脱氢酶(ADH,GH_A02G0728)和丙酮酸脱羧酶(PDC,GH_D09G1778)显著上调,但6-磷酸果糖激酶(PFK,GH_D05G0280),磷酸甘油酸激酶(PGK,GH_A01G0945和GH_D01G0967)和蔗糖合酶基因(SUS,GH_A06G0873和GH_D06G0851)在淹没处理中显著下调。在浸没胁迫下,次级代谢产物中萜烯生物合成途径相关基因受到调控。
结论:通过呼吸代谢调节萜烯生物合成可能在提高棉花对淹水的耐受性方面发挥作用。我们的研究结果表明,甲羟戊酸途径,发生在萜类骨架生物合成途径(ko00900)的细胞质中,可能是淹没应力的主要反应。