MPMI:中科院植物所田世平研究组发表真菌毒素生物合成研究进展

摘要 : 病原真菌一方面可引起果实腐烂造成巨大的经济损失，另一方面会产生真菌毒素威胁人类健康。

病原真菌一方面可引起果实腐烂造成巨大的经济损失，另一方面会产生真菌毒素威胁人类健康。近年来，真菌毒素诱发的食品安全问题越来越受到世界各国关注。由扩展青霉(Penicillium expansum)产生的棒曲霉素(Patulin)是造成果蔬及其加工制品污染的重要真菌毒素，然而棒曲霉素生物合成的分子基础及其调控机制并不清楚。

中科院植物研究所田世平研究组对两种青霉菌(扩展青霉P. expansum，能侵染多种不同种类的果实;意大利青霉P. italicum，只侵染柑橘类果实)进行了全基因组de novo测序，分别获得了33.52 Mb和28.99 Mb的高质量基因组草图。比较基因组学分析发现，P. expansum的次生代谢基因组群非常发达，包含55个次生代谢基因簇，数量相当于P. italicum的2倍。进一步研究发现，P. expansum中含有一个完整的棒曲霉素合成基因簇，该基因簇由15个基因组成，编码11个催化酶、3个转运蛋白和1个特异性转录因子。基因敲除实验证明PePatL和PePatK在棒曲霉素合成途径中起到关键作用。与之相比，P. italicum基因组仅含有3个棒曲霉素合成相关基因，因此不能产生棒曲霉素。

该研究结果为进一步解析棒曲霉素生物合成调控的分子机制以及青霉属真菌寄主专化性等生物学问题奠定了基础。

相关研究成果近期作为封面文章发表在植物病理学领域的著名学术期刊molecular Plant-Microbe Interactions上。田世平研究组的副研究员李博强和博士毕业生宗元元是该论文的并列第一作者。


扩展青霉和意大利青霉的形态、病害症状和基因组特征

原文链接：

genomic Characterization Reveals Insights Into Patulin Biosynthesis and Pathogenicity in Penicillium Species

原文摘要：

Penicillium species are fungal pathogens that infect crop plants worldwide. P. expansumdiffers from P. italicum and P. digitatum, all major postharvest pathogens of pome and citrus, in that the former is able to produce the mycotoxin patulin and has a broader host range. The molecular basis of host-specificity of fungal pathogens has now become the focus of recent research. The present report provides the whole genome sequence of P. expansum (33.52 Mb) and P. italicum (28.99 Mb) and identifies differences in genome structure, important pathogenic characters, and secondary metabolite (SM) gene clusters in Penicillium species. We identified a total of 55 gene clusters potentially related to secondary metabolism, including a cluster of 15 genes (named PePatA to PePatO), that may be involved in patulin biosynthesis in P. expansum. functional studies confirmed thatPePatL and PePatK play crucial roles in the biosynthesis of patulin and that patulin production is not related to virulence of P. expansum. Collectively, P. expansum contains more pathogenic genes and SM gene clusters, in particular, an intact patulin cluster, thanP. italicum or P. digitatum. These findings provide important information relevant to understanding the molecular network of patulin biosynthesis and mechanisms of host-specificity in Penicillium species.

DOI:http://dx.doi.org/10.1094/MPMI-12-14-0398-FI

作者：田世平

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