Plant Biotechnology and Bioinformatics, Institute of Plant Biology and Braunschweig Integrated Centre of Systems Biology (BRICS), TU Braunschweig, 38106, Brunswick, Germany.
Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, 600 036, India.
Sci Rep. 2023 Sep 5;13(1):14614. doi: 10.1038/s41598-023-41738-6.
Camptothecin is an important anticancer alkaloid produced by particular plant species. No suitable synthetic route has been established for camptothecin production yet, imposing a stress on plant-based production systems. Endophytes associated with these camptothecin-producing plants have been reported to also produce camptothecin and other high-value phytochemicals. A previous study identified a fungal endophyte Alternaria burnsii NCIM 1409, isolated from Nothapodytes nimmoniana, to be a sustainable producer of camptothecin. Our study provides key insights on camptothecin biosynthesis in this recently discovered endophyte. The whole genome sequence of A. burnsii NCIM 1409 was assembled and screened for biosynthetic gene clusters. Comparative studies with related fungi supported the identification of candidate genes involved in camptothecin synthesis and also helped to understand some aspects of the endophyte's defense against the toxic effects of camptothecin. No evidence for horizontal gene transfer of the camptothecin biosynthetic genes from the host plant to the endophyte was detected suggesting an independent evolution of the camptothecin biosynthesis in this fungus.
喜树碱是一种重要的抗癌生物碱，由特定的植物物种产生。目前尚未建立合适的喜树碱生产合成路线，这对基于植物的生产系统造成了压力。与这些产生喜树碱的植物相关的内生菌也被报道能产生喜树碱和其他高价值的植物化学物质。先前的一项研究从云南蓝果树中分离出一种真菌内生菌拟盘多毛孢 NCIM 1409，鉴定其为喜树碱的可持续生产者。我们的研究为这个最近发现的内生菌中喜树碱的生物合成提供了关键的见解。拟盘多毛孢 NCIM 1409 的全基因组序列被组装并筛选生物合成基因簇。与相关真菌的比较研究支持了参与喜树碱合成的候选基因的鉴定，也有助于了解内生菌对喜树碱毒性作用的一些防御机制。没有证据表明喜树碱生物合成基因从宿主植物横向转移到内生菌，这表明该真菌中喜树碱生物合成的独立进化。
