Paudel Bimal, Pedersen Connor, Yen Yang, Marzano Shin-Yi Lee
Department of Biology and Microbiology, South Dakota State University, Brookings, SD 57007, USA.
United States Department of Agriculture, Agricultural Research Service (USDA-ARS), Toledo, OH 43606, USA.
Microorganisms. 2022 Jul 23;10(8):1484. doi: 10.3390/microorganisms10081484.
Deoxynivalenol (DON) toxin production during the infection of in small grain crops is one of the most harmful virulence factors associated with economic losses. Metatranscriptome sequencing and RT-qPCR traced back that the only mycovirus infecting an isolate, designated as Fg-4-2, was a novel strain of Fusarium graminearum virus 1 (FgV1), designated as FgV1-SD4. The isolate Fg-4-2 showed significantly reduced virulence against wheat compared to the virus-free culture, designated as isolate Fg-4-1, which was obtained by deep freezing and single conidial germination. Notably, no DON accumulation was detected in the harvested wheat seeds infected by Fg-4-2, whereas ~18 ppm DON was detected in seeds infected by Fg-4-1. Comparison of the genome sequence of FgV1-SD4 with other identified strains of FgV1, i.e., FgV1-DK21 and FgV1-ch, indicates mutations on ORF-2 and the 3'-UTR in the genome that might be associated with hypovirulence. This mycovirus strain alone and specific genetic components of FgV1-SD4 can be further optimized to be developed as a biocontrol agent to reduce Fusarium head blight and to lower the DON accumulation levels in small grain crops due to this fungal disease.
脱氧雪腐镰刀菌烯醇（DON）毒素在小粒作物感染过程中的产生是与经济损失相关的最有害毒力因子之一。宏转录组测序和RT-qPCR追溯发现，唯一感染禾谷镰刀菌分离株（命名为Fg-4-2）的真菌病毒是禾谷镰刀菌病毒1（FgV1）的一个新菌株，命名为FgV1-SD4。与通过深度冷冻和单分生孢子萌发获得的无病毒培养物（命名为分离株Fg-4-1）相比，分离株Fg-4-2对小麦的毒力显著降低。值得注意的是，在受Fg-4-2感染的收获小麦种子中未检测到DON积累，而在受Fg-4-1感染的种子中检测到约18 ppm的DON。FgV1-SD4与其他已鉴定的FgV1菌株（即FgV1-DK21和FgV1-ch）的基因组序列比较表明，基因组中的ORF-2和3'-UTR上存在可能与低毒力相关的突变。这种真菌病毒菌株本身以及FgV1-SD4的特定遗传成分可以进一步优化，开发成一种生物防治剂，以减少赤霉病，并降低小粒作物因这种真菌病害而导致的DON积累水平。
