College of Agronomy & Biotechnology, Yunnan Agricultural University, Kunming 650201, China; Key Laboratory of Medicinal Plant Biology of Yunnan Province, Yunnan Agricultural University, Kunming 650201, China; National & Local Joint Engineering Research Center on Germplasm Innovation & Utilization of Chinese Medicinal Materials in Southwestern China, Yunnan Agricultural University, Kunming 650201, China.
College of Agronomy & Biotechnology, Yunnan Agricultural University, Kunming 650201, China; Key Laboratory of Medicinal Plant Biology of Yunnan Province, Yunnan Agricultural University, Kunming 650201, China; National & Local Joint Engineering Research Center on Germplasm Innovation & Utilization of Chinese Medicinal Materials in Southwestern China, Yunnan Agricultural University, Kunming 650201, China.
Plant Physiol Biochem. 2020 Sep;154:564-580. doi: 10.1016/j.plaphy.2020.06.049. Epub 2020 Jul 3.
The medicinal plant Panax notoginseng is considered a promising source of secondary metabolites due to its saponins. However, there are relatively few studies on the response of saponins to nitrogen (N) availability and the mechanisms underlying the N-driven regulation of saponins. Saponins content and saponins -related genes were analyzed in roots of P. notoginseng grown under low N (LN), moderate N (MN) and high N (HN). Saponins was obviously increased in LN individuals with a reduction in β-glucosidase activity. LN facilitated root architecture and N uptake rate. Compared with the LN individuals, 2872 and 1122 genes were incorporated into as differently expressed genes (DEGs) in the MN and HN individuals. Clustering and enrichment showed that DEGs related to "carbohydrate biosynthesis", "plant hormone signal transduction", "terpenoid backbone biosynthesis", "sesquiterpenoid and triterpenoid biosynthesis" were enriched. The up-regulation of some saponins-related genes and microelement transporters was found in LN plants. Whereas the expression of IPT3, AHK4 and GS2 in LN plants fell far short of that in HN ones. Anyways, LN-induced accumulation of C-based metabolites as saponins might derive from the interaction between N and phytohormones in processing of N acquisition, and HN-induced reduction of saponins might be result from an increase in the form of β-glucosidase activity and N-dependent cytokinins (CKs) biosynthesis.
药用植物三七因其所含的皂甙而被认为是次生代谢产物的有前途的来源。然而，关于皂甙对氮（N）供应的响应及其与 N 驱动的皂甙调节相关的机制的研究相对较少。在低氮（LN）、中氮（MN）和高氮（HN）条件下生长的三七根中分析了皂甙含量和与皂甙相关的基因。在 LN 个体中，β-葡萄糖苷酶活性降低，皂甙明显增加。LN 促进了根系结构和氮吸收速率。与 LN 个体相比，MN 和 HN 个体中分别有 2872 个和 1122 个基因被纳入差异表达基因（DEGs）。聚类和富集表明，与“碳水化合物生物合成”、“植物激素信号转导”、“萜类骨架生物合成”、“倍半萜和三萜生物合成”相关的 DEGs 被富集。在 LN 植物中发现了一些与皂甙相关的基因和微量元素转运蛋白的上调。然而，在 LN 植物中，IPT3、AHK4 和 GS2 的表达远远低于 HN 植物。无论如何，LN 诱导的 C 基代谢物（如皂甙）的积累可能源自 N 和植物激素之间的相互作用，在氮吸收过程中，而 HN 诱导的皂甙减少可能是由于β-葡萄糖苷酶活性的增加和 N 依赖性细胞分裂素（CKs）生物合成所致。
