Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
BMC Microbiol. 2013 Mar 28;13:71. doi: 10.1186/1471-2180-13-71.
Endophytic fungi represent underexplored resource of novel lead compounds and have a capacity to produce diverse class of plant secondary metabolites. Here we investigated endophytic fungi diversity and screening of paclitaxel-producing fungi from Taxus x media.
Eighty-one endophytic fungi isolated from T. media were grouped into 8 genera based on the morphological and molecular identification. Guignardia and Colletotrichum were the dominant genera, whereas the remaining genera were infrequent groups. The genera Glomerella and Gibberella were first reported in Taxus. Three representative species of the distinct genera gave positive hits by molecular marker screening and were capable of producing taxol which were validated by HPLC-MS. Among these 3 taxol-producing fungi, the highest yield of taxol was 720 ng/l by Guignardia mangiferae HAA11 compared with those of Fusarium proliferatum HBA29 (240 ng/l) and Colletotrichum gloeosporioides TA67 (120 ng/l). This is the first report of taxol producer from Guignardia. Moreover, the lower similarities of ts and bapt between microbial and plant origin suggested that fungal taxol biosynthetic cluster might be repeatedly invented during evolution, nor horizontal gene transfer from Taxus species.
Taxol-producing endophytic fungi could be a fascinating reservoir to generate taxol-related drug lead and to elucidate the remained 5 unknown genes or the potential regulation mechanism in the taxol biosynthesis pathway.
内生真菌是尚未充分开发的新型先导化合物资源，具有产生多种植物次生代谢产物的能力。本研究从红豆杉中调查了内生真菌的多样性和紫杉醇产生菌的筛选。
根据形态学和分子鉴定，从红豆杉中分离出的 81 株内生真菌分为 8 个属。钩丝壳属和炭疽菌属是优势属，而其余属是罕见属。球腔菌属和镰刀菌属是在红豆杉中首次报道的。通过分子标记筛选，3 种不同属的代表种呈阳性反应，且能产生紫杉醇，这通过 HPLC-MS 得到了验证。在这 3 株产紫杉醇的真菌中，与层出镰刀菌 HBA29（240ng/L）和胶孢炭疽菌 TA67（120ng/L）相比，芒果球腔菌 HAA11 的紫杉醇产量最高，为 720ng/L。这是首次从钩丝壳属中报道紫杉醇的产生。此外，微生物和植物来源的 ts 和 bapt 之间的相似性较低，表明真菌紫杉醇生物合成簇可能在进化过程中被反复发明，而不是来自红豆杉属的水平基因转移。
产紫杉醇的内生真菌可能是一个引人入胜的资源库，可以产生与紫杉醇相关的药物先导化合物，并阐明紫杉醇生物合成途径中剩余的 5 个未知基因或潜在的调控机制。
