Key Laboratory of Medicinal Resources and Natural Pharmaceutical Chemistry (Shaanxi Normal University), The Ministry of Education, Xi'an, Shaanxi, 710119, People's Republic of China.
National Engineering Laboratory for Resources Development of Endangered Crude Drugs in Northwest China, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi, 710119, People's Republic of China.
BMC Plant Biol. 2022 Feb 22;22(1):78. doi: 10.1186/s12870-022-03455-6.
Glucosinolates (GSLs) play important roles in defending against exogenous damage and regulating physiological activities in plants. However, GSL accumulation patterns and molecular regulation mechanisms are largely unknown in Isatis indigotica Fort.
Ten GSLs were identified in I. indigotica, and the dominant GSLs were epiprogoitrin (EPI) and indole-3-methyl GSL (I3M), followed by progoitrin (PRO) and gluconapin (GNA). The total GSL content was highest (over 20 μmol/g) in reproductive organs, lowest (less than 1.0 μmol/g) in mature organs, and medium in fresh leaves (2.6 μmol/g) and stems (1.5 μmol/g). In the seed germination process, the total GSL content decreased from 27.2 μmol/g (of seeds) to 2.7 μmol/g (on the 120th day) and then increased to 4.0 μmol/g (180th day). However, the content of indole GSL increased rapidly in the first week after germination and fluctuated between 1.13 μmol/g (28th day) and 2.82 μmol/g (150th day). Under the different elicitor treatments, the total GSL content increased significantly, ranging from 2.9-fold (mechanical damage, 3 h) to 10.7-fold (MeJA, 6 h). Moreover, 132 genes were involved in GSL metabolic pathways. Among them, no homologs of AtCYP79F2 and AtMAM3 were identified, leading to a distinctive GSL profile in I. indigotica. Furthermore, most genes involved in the GSL metabolic pathway were derived from tandem duplication, followed by dispersed duplication and segmental duplication. Purifying selection was observed, although some genes underwent relaxed selection. In addition, three tandem-arrayed GSL-OH genes showed different expression patterns, suggesting possible subfunctionalization during evolution.
Ten different GSLs with their accumulation patterns and 132 genes involved in the GSL metabolic pathway were explored, which laid a foundation for the study of GSL metabolism and regulatory mechanisms in I. indigotica.
芥子油苷（GSLs）在抵御外源损伤和调节植物生理活动方面发挥着重要作用。然而，在菘蓝中，GSL 积累模式和分子调控机制在很大程度上尚不清楚。
在菘蓝中鉴定出 10 种 GSLs，其中以表告依春（EPI）和吲哚-3-甲基 GSL（I3M）为主，其次是前告依春（PRO）和葡萄糖芸香苷（GNA）。生殖器官中的总 GSL 含量最高（超过 20 μmol/g），成熟器官中的总 GSL 含量最低（低于 1.0 μmol/g），新鲜叶片和茎中的总 GSL 含量中等（分别为 2.6 μmol/g 和 1.5 μmol/g）。在种子萌发过程中，总 GSL 含量从 27.2 μmol/g（种子）降低到 2.7 μmol/g（第 120 天），然后增加到 4.0 μmol/g（第 180 天）。然而，吲哚 GSL 的含量在萌发后第一周迅速增加，在 1.13 μmol/g（第 28 天）和 2.82 μmol/g（第 150 天）之间波动。在不同的诱导剂处理下，总 GSL 含量显著增加，范围从 2.9 倍（机械损伤，3 h）到 10.7 倍（MeJA，6 h）。此外，132 个基因参与了 GSL 代谢途径。其中，未鉴定出 AtCYP79F2 和 AtMAM3 的同源物，导致菘蓝中具有独特的 GSL 图谱。此外，参与 GSL 代谢途径的大多数基因来自串联重复，其次是分散重复和片段重复。虽然一些基因经历了松弛选择，但观察到了纯化选择。此外，三个串联排列的 GSL-OH 基因表现出不同的表达模式，这表明在进化过程中可能存在亚功能化。
探索了 10 种不同的 GSL 及其积累模式，以及参与 GSL 代谢途径的 132 个基因，为研究菘蓝中 GSL 代谢和调控机制奠定了基础。
