Pan Qifang, Wang Chenyi, Xiong Zhiwei, Wang Hang, Fu Xueqing, Shen Qian, Peng Bowen, Ma Yanan, Sun Xiaofen, Tang Kexuan
Plant Biotechnology Research Center, Fudan-SJTU-Nottingham Plant Biotechnology R&D Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China.
Instrumental Analysis Center, Shanghai Jiao Tong University, Shanghai, China.
Front Plant Sci. 2019 Jul 18;10:931. doi: 10.3389/fpls.2019.00931. eCollection 2019.
contains a variety of monoterpenoid indole alkaloids (MIAs), among which bisindole alkaloids vinblastine and vincristine are well-known to have antitumor effects and widely used in clinical treatment. However, their contents in is extremely low and difficult to meet market demands. Therefore, it is of great significance to study the transcriptional regulation mechanism of MIAs biosynthesis for high yielding of bisindole alkaloids in . Studies have shown that MIAs biosynthesis in has complex temporal and spacial specificity and is under tight transcriptional regulation, especially bisindole alkaloids. In this study, an AP2/ERF transcription factor CrERF5 was selected by RNA-seq of organs, and its full-length sequence was cloned and characterized. CrERF5 responds to both ethylene and JA signals and is localized in the nucleus. CrERF5 could activate the transcriptional activity of the TDC promoter. Transient overexpressing CrERF5 in petals caused a significant increase of the expression levels of key genes in both the upstream and downstream pathways of MIAs biosynthesis while silencing resulted in a decrease of them. Accordingly, the contents of bisindole alkaloids anhydrovinblastine and vinblastine, monoindole alkaloids ajmalicine, vindoline, and catharanthine were strongly enhanced in -overexpressing petals while their contents decreased in -silenced plants. These results suggested that CrERF5 is a novel positive ethylene-JA-inducible AP2/ERF transcription factor upregulating the MIAs biosynthetic pathway leading to the bisindole alkaloids accumulation.
含有多种单萜吲哚生物碱（MIAs），其中双吲哚生物碱长春碱和长春新碱具有抗肿瘤作用且在临床治疗中广泛应用，这是众所周知的。然而，它们在[植物名称]中的含量极低，难以满足市场需求。因此，研究MIAs生物合成的转录调控机制对于提高[植物名称]中双吲哚生物碱的产量具有重要意义。研究表明，[植物名称]中MIAs的生物合成具有复杂的时空特异性，并且受到严格的转录调控，尤其是双吲哚生物碱。在本研究中，通过对[植物名称]器官进行RNA测序筛选出一个AP2/ERF转录因子CrERF5，并克隆和鉴定了其全长序列。CrERF5对乙烯和茉莉酸（JA）信号均有响应，且定位于细胞核。CrERF5能够激活TDC启动子的转录活性。在[植物名称]花瓣中瞬时过表达CrERF5导致MIAs生物合成上下游途径关键基因的表达水平显著增加，而沉默[基因名称]则导致这些基因表达水平下降。相应地，在过表达CrERF5的花瓣中，双吲哚生物碱脱水长春碱和长春碱、单吲哚生物碱阿吗碱、文朵灵和长春质碱的含量显著增加，而在沉默[基因名称]的植株中它们的含量下降。这些结果表明，CrERF5是一种新型的乙烯 - JA诱导型AP2/ERF转录因子，可上调MIAs生物合成途径，导致双吲哚生物碱积累。
