Xu Jiao, Hu Zhengping, He Hua, Ou Xiaohong, Yang Yang, Xiao Chenghong, Yang Changgui, Li Liangyuan, Jiang Weike, Zhou Tao
Resource Institute for Chinese Medicine and Ethnic Materia Medica, Guizhou University of Traditional Chinese Medicine, Guiyang, China.
Front Plant Sci. 2022 Dec 22;13:1022075. doi: 10.3389/fpls.2022.1022075. eCollection 2022.
is a perennial herb, the roots of which are abundant in asperosaponin VI, which has important medicinal value. However, the molecular mechanism underlying the biosynthesis of asperosaponin VI in remains unclear. In present study, a comprehensive investigation of asperosaponin VI biosynthesis was conducted at the levels of metabolite and transcript during root development. The content of asperosaponin VI was significantly accumulated in two-leaf stage roots, and the spatial distribution of asperosaponin VI was localized in the xylem. The concentration of asperosaponin VI gradually increased in the root with the development process. Transcriptome analysis revealed 3916 unique differentially expressed genes (DEGs) including 146 transcription factors (TFs) during root development in . In addition, α-linolenic acid metabolism, jasmonic acid (JA) biosynthesis, JA signal transduction, sesquiterpenoid and triterpenoid biosynthesis, and terpenoid backbone biosynthesis were prominently enriched. Furthermore, the concentration of JA gradually increased, and genes involved in α-linolenic acid metabolism, JA biosynthesis, and triterpenoid biosynthesis were up-regulated during root development. Moreover, the concentration of asperosaponin VI was increased following methyl jasmonate (MeJA) treatment by activating the expression of genes in the triterpenoid biosynthesis pathway, including acetyl-CoA acetyltransferase (), 3-hydroxy-3-methylglutaryl coenzyme A synthase (), 3-hydroxy-3-methylglutaryl coenzyme-A reductase (). We speculate that JA biosynthesis and signaling regulates the expression of triterpenoid biosynthetic genes and facilitate the biosynthesis of asperosaponin VI. The results suggest a regulatory network wherein triterpenoids, JA, and TFs co-modulate the biosynthesis of asperosaponin VI in .
是一种多年生草本植物，其根中富含齐墩果酸皂苷VI，具有重要的药用价值。然而，齐墩果酸皂苷VI在该植物中的生物合成分子机制尚不清楚。在本研究中，在根发育过程中，从代谢物和转录水平对齐墩果酸皂苷VI的生物合成进行了全面研究。齐墩果酸皂苷VI的含量在二叶期根中显著积累，并且其空间分布定位于木质部。随着发育进程，根中齐墩果酸皂苷VI的浓度逐渐增加。转录组分析揭示了在该植物根发育过程中有3916个独特的差异表达基因（DEG），包括146个转录因子（TF）。此外，α-亚麻酸代谢、茉莉酸（JA）生物合成、JA信号转导、倍半萜和三萜生物合成以及萜类骨架生物合成显著富集。此外，JA的浓度逐渐增加，并且参与α-亚麻酸代谢、JA生物合成和三萜生物合成的基因在根发育过程中上调。而且，通过激活三萜生物合成途径中的基因表达，包括乙酰辅酶A乙酰转移酶（）、3-羟基-3-甲基戊二酰辅酶A合酶（）、3-羟基-3-甲基戊二酰辅酶A还原酶（），茉莉酸甲酯（MeJA）处理后齐墩果酸皂苷VI的浓度增加。我们推测JA生物合成和信号传导调节三萜生物合成基因的表达并促进齐墩果酸皂苷VI的生物合成。结果表明了一个调控网络，其中三萜、JA和TF共同调节该植物中齐墩果酸皂苷VI的生物合成。
