The Key Laboratory for Silviculture and Conservation of Ministry of Education, Beijing Forestry University, Beijing, 100083, China.
Beijing Advanced Innovation Center for Tree Breeding By Molecular Design, Beijing Forestry University, Beijing, 100083, China.
Plant Physiol Biochem. 2021 Nov;168:410-422. doi: 10.1016/j.plaphy.2021.10.022. Epub 2021 Oct 21.
Flavonoids are important metabolites of pigeon pea in relation to its stress resistance. However, the molecular basis and regulatory mechanisms of flavonoids in pigeon pea remain unclear. Methyl jasmonate (MeJA) is a signaling molecule associated with biosynthesis of flavonoids. In this study, after exogenous treatment of 10 mg/L MeJA, infection of pathogenic fungi to pigeon pea was alleviated and the content of flavonoids was increased. Results of gene expression and metabolic changes that were respectively analyzed by transcriptome sequencing and high performance liquid chromatography (HPLC) showed that (1) concentrations of various flavonoids, such as genistein, apigenin, vitexin and biochanin A were significantly up-regulated; (2) 13675 differentially expressed genes were produced, mainly enriched in signal transduction and isoflavone biosynthesis pathways: (3) the expression levels of key synthase genes (CcI2'H, CcHIDH, Cc7-IOMT) in the flavonoid biosynthesis pathway were significantly up-regulated; (4) Overexpression of CcbHLH35 significantly induced upregulation of flavonoid synthase genes and accumulation of genistein, vitexin and apigenin. Our findings reveals the pivotal roles of MeJA in synthesis and functioning of flavonoids in pigeon pea, which provide a basis for further studies on flavonoid-mediated defense responses.
类黄酮是羽扇豆与抗逆性相关的重要代谢物。然而，羽扇豆中类黄酮的分子基础和调控机制尚不清楚。茉莉酸甲酯（MeJA）是与类黄酮生物合成相关的信号分子。本研究在羽扇豆受到病原菌感染时，用 10mg/L 的 MeJA 进行外源处理，结果发现感染减轻，类黄酮含量增加。通过转录组测序和高效液相色谱（HPLC）分别分析基因表达和代谢变化的结果表明：（1）染料木黄酮、芹菜素、牡荆素和大豆苷元等各种类黄酮的浓度明显上调；（2）产生了 13675 个差异表达基因，主要富集在信号转导和异黄酮生物合成途径中；（3）类黄酮生物合成途径中关键合酶基因（CcI2'H、CcHIDH、Cc7-IOMT）的表达水平显著上调；（4）过表达 CcbHLH35 可显著诱导类黄酮合酶基因的上调和染料木黄酮、牡荆素和芹菜素的积累。这些发现揭示了 MeJA 在羽扇豆中类黄酮合成和功能中的关键作用，为进一步研究类黄酮介导的防御反应提供了依据。
