Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, Jiangsu 210014, China; Key Laboratory of Sustainable Crop Production in the Middle Reaches of the Yangtze River (Co-construction by Ministry and Province), College of Agriculture, Yangtze University, Jingzhou, Hubei 434025, China.
Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, Jiangsu 210014, China; Jiangsu Co-Innovation Centre for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou, Jiangsu 225009, China.
Microbiol Res. 2024 Aug;285:127784. doi: 10.1016/j.micres.2024.127784. Epub 2024 May 27.
Fusarium crown rot (FCR) caused by Fusarium pseudograminearum poses a significant threat to wheat production in the Huang-Huai-Hai region of China. However, the pathogenic mechanism of F. pseudograminearum is still poorly understood. ZnCys transcription factors, which are exclusive to fungi, play pivotal roles in regulating fungal development, drug resistance, pathogenicity, and secondary metabolism. In this study, we present the functional characterization of a ZnCys transcription factor F. pseudograminearum, designated Fp487. In F. pseudograminearum, Fp487 is shown to be required for mycelial growth through gene knockout and phenotypic analyses. Compared with wild-type CF14047, the ∆Fp487 mutant displayed a slight reduction in growth rate but a significant decrease in conidiogenesis, pathogenicity and 3-acetyl-deoxynivalenol (3AcDON) production. Moreover, the mutant exhibited heightened sensitivity to oxidative and cytomembrane stress. Furthermore, we synthesized dsRNA from the Fp487 gene in vitro, resulting in a reduction in the growth rate of F. pseudograminearum and its virulence on barley leaves through spray-induced gene silencing (SIGS). Notably, this study makes the first instance of inducing the expression of abundant dsRNA from F. pseudograminearum by engineering the Escherichia coli strain HT115 (DE3) and utilizing the SIGS technique to evaluate the virulence effect of dsRNA on F. pseudograminearum. In conclusion, our findings revealed the crucial role of Fp487 in regulating pathogenicity, stress responses, DON production, and conidiogenesis in F. pseudograminearum. Furthermore, Fp487 is a potential RNAi-based target for FCR control.
镰刀菌顶腐病（FCR）是由禾谷镰刀菌（ Fusarium pseudograminearum ）引起的，对中国黄淮海地区的小麦生产构成了重大威胁。然而，禾谷镰刀菌的致病机制仍知之甚少。ZnCys 转录因子是真菌所特有的，在调控真菌发育、药物抗性、致病性和次生代谢等方面发挥着关键作用。在这项研究中，我们对禾谷镰刀菌的一个 ZnCys 转录因子 Fp487 进行了功能表征。在禾谷镰刀菌中，通过基因敲除和表型分析表明，Fp487 对于菌丝生长是必需的。与野生型 CF14047 相比，Δ Fp487 突变体的生长速度略有降低，但产孢量、致病性和 3-乙酰脱氧雪腐镰刀菌烯醇（3AcDON）产量显著降低。此外，突变体对氧化和细胞质膜应激的敏感性增强。此外，我们在体外合成了 Fp487 基因的 dsRNA，通过喷雾诱导基因沉默（SIGS）导致禾谷镰刀菌的生长速度降低及其对大麦叶片的毒力降低。值得注意的是，本研究首次通过工程大肠杆菌菌株 HT115（DE3）诱导禾谷镰刀菌大量 dsRNA 的表达，并利用 SIGS 技术评估 dsRNA 对禾谷镰刀菌毒力的影响。总之，我们的研究结果揭示了 Fp487 在调控禾谷镰刀菌致病性、应激反应、DON 产生和产孢方面的重要作用。此外，Fp487 是一种潜在的基于 RNAi 的 FCR 控制靶标。
