Hu Xiaojia, Qin Lu, Roberts Daniel P, Lakshman Dilip K, Gong Yangmin, Maul Jude E, Xie Lihua, Yu Changbing, Li Yinshui, Hu Lei, Liao Xiangsheng, Liao Xing
Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan, 430062, People's Republic of China.
Sustainable Agricultural Systems Laboratory, Henry A. Wallace Beltsville Agricultural Research Center, USDA-Agricultural Research Service, Beltsville, MD, 20705-2350, USA.
BMC Genomics. 2017 Aug 31;18(1):674. doi: 10.1186/s12864-017-4016-8.
The biological control agent Aspergillus aculeatus Asp-4 colonizes and degrades sclerotia of Sclerotinia sclerotiorum resulting in reduced germination and disease caused by this important plant pathogen. Molecular mechanisms of mycoparasites underlying colonization, degradation, and reduction of germination of sclerotia of this and other important plant pathogens remain poorly understood.
An RNA-Seq screen of Asp-4 growing on autoclaved, ground sclerotia of S. sclerotiorum for 48 h identified 997 up-regulated and 777 down-regulated genes relative to this mycoparasite growing on potato dextrose agar (PDA) for 48 h. qRT-PCR time course experiments characterized expression dynamics of select genes encoding enzymes functioning in degradation of sclerotial components and management of environmental conditions, including environmental stress. This analysis suggested co-temporal up-regulation of genes functioning in these two processes. Proteomic analysis of Asp-4 growing on this sclerotial material for 48 h identified 26 up-regulated and 6 down-regulated proteins relative to the PDA control. Certain proteins with increased abundance had putative functions in degradation of polymeric components of sclerotia and the mitigation of environmental stress.
Our results suggest co-temporal up-regulation of genes involved in degradation of sclerotial compounds and mitigation of environmental stress. This study furthers the analysis of mycoparasitism of sclerotial pathogens by providing the basis for molecular characterization of a previously uncharacterized mycoparasite-sclerotial interaction.
生防菌棘孢曲霉Asp-4能够定殖并降解核盘菌的菌核，从而降低这种重要植物病原菌的萌发率及致病力。对于这种及其他重要植物病原菌，其菌核的定殖、降解及萌发率降低背后的真菌寄生分子机制仍知之甚少。
对在高压灭菌的磨碎核盘菌菌核上生长48小时的Asp-4进行RNA测序筛选，相对于在马铃薯葡萄糖琼脂（PDA）上生长48小时的该真菌寄生菌，共鉴定出997个上调基因和777个下调基因。qRT-PCR时间进程实验表征了选择的编码在菌核成分降解及环境条件管理（包括环境胁迫）中起作用的酶的基因的表达动态。该分析表明在这两个过程中起作用的基因同时上调。对在这种菌核材料上生长48小时的Asp-4进行蛋白质组分析，相对于PDA对照，鉴定出26个上调蛋白和6个下调蛋白。某些丰度增加的蛋白在菌核聚合物成分降解及环境胁迫缓解方面具有推定功能。
我们的结果表明，参与菌核化合物降解和环境胁迫缓解的基因同时上调。本研究通过为先前未表征的真菌寄生菌 - 菌核相互作用的分子表征提供基础，进一步分析了菌核病原菌的真菌寄生作用。
