Pan Aikun, Gao Haiqiao, Lin Ying, Yang Bingrun, Chang Chunhao, Liu Zhiwen, Wang Yanyan, Jin Zhaoxia, Yu Fang
School of Biological Engineering, Dalian Polytechnic University, Dalian, 116034, China.
College of Chemistry, Chemical Engineering and Resource Utilization, Northeast Forestry University, Harbin, 150040, China.
J Plant Res. 2025 Jun 6. doi: 10.1007/s10265-025-01646-4.
Jasmonate resistant 1 (JAR1), which encodes a jasmonate-amino synthase, mediates the biosynthesis of jasmonoyl-isoleucine (JA-Ile), the bioactive form of jasmonate involved in JA signal transduction pathway. Although JAR1 has been characterized in several plant species, its regulatory function in mediating JA signaling to modulate the biosynthesis of terpenoid indole alkaloids (TIAs) in Catharanthus roseus, a medicinal and ornamental plant, have not been previously investigated. In this study, we have identified and cloned CrJAR1, a member of the Gretchen Hagen3 (GH3) gene family, from C. roseus and confirmed its enzymatic activity in JA-Ile formation via heterologous expression in E. coli. Functional analyses using transient overexpression and virus-induced gene silencing (VIGS) in C. roseus leaves revealed that CrJAR1 positively regulates the accumulation of catharanthine and vindoline. Moreover, we demonstrated that CrCOI1, the jasmonate receptor, functions synergistically with CrJAR1 in modulating TIA biosynthesis. Co-silencing of CrCOI1 and CrJAR1 resulted in a lower sensitivity to exogenous JA treatment compared to silencing of CrJAR1 alone, indicating distinct yet complementary roles in jasmonate-mediated metabolic regulation. These results advance our understanding the function of CrJAR1 and offer new strategies for engineering specialized metabolite biosynthesis in plants.
茉莉酸抗性1（JAR1）编码一种茉莉酸 - 氨基合成酶，介导茉莉酰异亮氨酸（JA - Ile）的生物合成，JA - Ile是参与茉莉酸信号转导途径的茉莉酸生物活性形式。尽管JAR1已在多种植物物种中得到表征，但其在介导茉莉酸信号以调节药用和观赏植物长春花中萜类吲哚生物碱（TIAs）生物合成方面的调控功能此前尚未被研究。在本研究中，我们从长春花中鉴定并克隆了Gretchen Hagen3（GH3）基因家族成员CrJAR1，并通过在大肠杆菌中的异源表达证实了其在JA - Ile形成中的酶活性。利用长春花叶片中的瞬时过表达和病毒诱导基因沉默（VIGS）进行的功能分析表明，CrJAR1正向调节长春碱和文多灵的积累。此外，我们证明了茉莉酸受体CrCOI1在调节TIAs生物合成中与CrJAR1协同发挥作用。与单独沉默CrJAR1相比，同时沉默CrCOI1和CrJAR1对外源茉莉酸处理的敏感性更低，表明它们在茉莉酸介导的代谢调节中具有不同但互补的作用。这些结果增进了我们对CrJAR1功能的理解，并为植物中特殊代谢物生物合成的工程改造提供了新策略。
