College of Forestry, Shanxi Agricultural University, Taigu, Shanxi, China.
Shanxi Key Laboratory of Functional Oil Tree Cultivation and Research, Taigu, Shanxi, China.
PLoS One. 2020 Jul 24;15(7):e0236588. doi: 10.1371/journal.pone.0236588. eCollection 2020.
Xanthoceras sorbifolia, a medicinal and oil-rich woody plant, has great potential for biodiesel production. However, little study explores the link between gene expression level and metabolite accumulation of X. sorbifolia in response to cold stress. Herein, we performed both transcriptomic and metabolomic analyses of X. sorbifolia seedlings to investigate the regulatory mechanism of resistance to low temperature (4 °C) based on physiological profile analyses. Cold stress resulted in a significant increase in the malondialdehyde content, electrolyte leakage and activity of antioxidant enzymes. A total of 1,527 common differentially expressed genes (DEGs) were identified, of which 895 were upregulated and 632 were downregulated. Annotation of DEGs revealed that amino acid metabolism, glycolysis/gluconeogenesis, starch and sucrose metabolism, galactose metabolism, fructose and mannose metabolism, and the citrate cycle (TCA) were strongly affected by cold stress. In addition, DEGs within the plant mitogen-activated protein kinase (MAPK) signaling pathway and TF families of ERF, WRKY, NAC, MYB, and bHLH were transcriptionally activated. Through metabolomic analysis, we found 51 significantly changed metabolites, particularly with the analysis of primary metabolites, such as sugars, amino acids, and organic acids. Moreover, there is an overlap between transcript and metabolite profiles. Association analysis between key genes and altered metabolites indicated that amino acid metabolism and sugar metabolism were enhanced. A large number of specific cold-responsive genes and metabolites highlight a comprehensive regulatory mechanism, which will contribute to a deeper understanding of the highly complex regulatory program under cold stress in X. sorbifolia.
文冠果是一种药用和富油的木本植物，具有很大的生物柴油生产潜力。然而，很少有研究探讨文冠果基因表达水平与应对冷胁迫时代谢物积累之间的联系。在此，我们对文冠果幼苗进行了转录组和代谢组分析，根据生理特征分析研究了其低温（4°C）抗性的调节机制。冷胁迫导致丙二醛含量、电解质泄漏和抗氧化酶活性显著增加。共鉴定出 1527 个共同差异表达基因（DEGs），其中 895 个上调，632 个下调。DEGs 的注释表明，氨基酸代谢、糖酵解/糖异生、淀粉和蔗糖代谢、半乳糖代谢、果糖和甘露糖代谢以及柠檬酸循环（TCA）受到冷胁迫的强烈影响。此外，植物丝裂原活化蛋白激酶（MAPK）信号通路和 ERF、WRKY、NAC、MYB 和 bHLH 家族的 TF 中的 DEGs 被转录激活。通过代谢组学分析，我们发现 51 种显著变化的代谢物，特别是对糖、氨基酸和有机酸等初级代谢物的分析。此外，转录组和代谢组谱之间存在重叠。关键基因和改变的代谢物之间的关联分析表明，氨基酸代谢和糖代谢得到了增强。大量特定的冷响应基因和代谢物突出了一个全面的调节机制，这将有助于更深入地了解文冠果在冷胁迫下高度复杂的调节程序。
