School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing 210023, China.
College of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou 311402, China.
Biochim Biophys Acta Proteins Proteom. 2021 Aug;1869(8):140671. doi: 10.1016/j.bbapap.2021.140671. Epub 2021 May 12.
Protostane triterpenes in Alisma orientale (Sam.) Juz. have unique structural features with distinct pharmacological activities. Previously we have demonstrated that protostane triterpene biosynthesis could be regulated by methyl jasmonate (MeJA) induction in A. orientale. Here, proteomic investigation reveals the MeJA mediated regulation of protostane triterpene biosynthesis. In our study, 281 differentially abundant proteins were identified from MeJA-treated compared to control groups, while they were mainly associated with triterpene biosynthesis, α-linolenic acid metabolism, carbohydrate metabolism and response to stress/defense. Key enzymes 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR), squalene epoxidase (SE), oxidosqualene cyclase (OSC) and cytochrome P450s which potentially involved in protostane triterpene biosynthesis were significantly enriched in MeJA-treated group. Basic Helix-loop-helix (bHLH), MYB, and GRAS transcription factors were enhanced after MeJA treatment, and they also improved the expressions of key enzymes in Mevalonate pathway and protostane triterpene. Then, MeJA also could increase the expression of α-galactosidase (α-GAL), thereby promoting carbohydrate decomposition, and providing energy and carbon skeletons for protostane triterpene precursor biosynthesis. As well, exogenous MeJA treatment upregulated 13-lipoxygenase (13-LOX), allene oxide synthase (AOS) and allene oxide cyclase (AOC) involved in α-linolenic acid metabolism, leading to the accumulation of endogenous MeJA and activation of the protostane triterpene biosynthesis transduction. Finally, MeJA upregulated stress/defence-related proteins, as to enhance the defence responses activity of plants. These results were further verified by quantitative real-time PCR analysis of 19 selected genes and content analysis of protostane triterpene. The results provide some new insights into the role of MeJA in protostane triterpene biosynthesis.
泽泻中的原甾烷三萜具有独特的结构特征和明显的药理活性。以前我们已经证明，原甾烷三萜的生物合成可以通过甲基茉莉酸（MeJA）诱导在泽泻中得到调节。在这里，蛋白质组学研究揭示了 MeJA 介导的原甾烷三萜生物合成的调节。在我们的研究中，从 MeJA 处理组与对照组相比，鉴定出 281 个差异丰度蛋白，而它们主要与三萜生物合成、α-亚麻酸代谢、碳水化合物代谢和应激/防御反应有关。关键酶 3-羟-3-甲基戊二酰辅酶 A 还原酶（HMGR）、角鲨烯环氧化酶（SE）、氧化鲨烯环化酶（OSC）和细胞色素 P450s 可能参与原甾烷三萜的生物合成，在 MeJA 处理组中明显富集。碱性螺旋-环-螺旋（bHLH）、MYB 和 GRAS 转录因子在 MeJA 处理后增强，它们也提高了甲羟戊酸途径和原甾烷三萜的关键酶的表达。然后，MeJA 还可以增加α-半乳糖苷酶（α-GAL）的表达，从而促进碳水化合物分解，为原甾烷三萜前体的生物合成提供能量和碳骨架。此外，外源 MeJA 处理上调了 13-脂氧合酶（13-LOX）、丙二烯氧化物合酶（AOS）和丙二烯氧化物环化酶（AOC），它们参与α-亚麻酸代谢，导致内源性 MeJA 的积累和原甾烷三萜生物合成转导的激活。最后，MeJA 上调了应激/防御相关蛋白，以增强植物的防御反应活性。这些结果通过对 19 个选定基因的定量实时 PCR 分析和原甾烷三萜的含量分析得到了进一步验证。结果为 MeJA 在原甾烷三萜生物合成中的作用提供了一些新的见解。
