Zhang Jie, Chai Qiuyuan, Goodwin Paul H, Zhu Wenqian, Xia Mingcong, Sun Runhong, Xu Wen, Wu Chao, Song Yajing, Dong Qianqian, Yang Lirong
Institute of Plant Protection Research, Henan Academy of Agricultural Sciences, Henan Biopesticide Engineering Research Center, Henan International Joint Laboratory of Crop Protection, Zhengzhou, P. R. China.
School of Environmental Sciences, University of Guelph, Guelph, Canada.
Plant Cell Environ. 2025 Sep;48(9):6587-6604. doi: 10.1111/pce.15622. Epub 2025 May 23.
A cystathionine β-synthase (CBS) gene, FpCBS, of the wheat crown rot pathogen, Fusarium pseudograminearum, was identified. FpCBS was highly expressed during conidiation and the early phases of infection. Compared to the wild-type and FpCBS complemented strains, the FpCBS deletion strain had a similar hyphal morphology and growth rate but reduced conidiation. In culture, the FpCBS deletion strain showed broad-scale changes with a decrease in HS levels, changes in sulphur-containing amino acids and 1207 differentially expressed proteins. The deletion strain also showed reduced deoxynivalenol (DON) production, cellophane penetration ability, antioxidant capacity, as well as increased hyphal iron levels, sensitivity to HO and lipid peroxidation. During infection, the ΔFpcbs strain showed diminished virulence to wheat with fewer penetration structures, and there was a stronger host defence response with wheat epidermal cells having thickened walls and greater reactive oxygen species accumulation. Transcriptomic analysis of infected leaves showed 1954 differentially expressed genes in the FpCBS deletion strain compared to the wild-type strain. This included genes for sulphur metabolism, antioxidative defence, plant cell wall-degrading enzymes and trichothecene production. FpCBS not only plays a pivotal role in sulphur metabolism and HS production, but it is also important for a broad range of fungal functions, including iron homoeostasis, mycotoxin production and development (conidiation and penetration structures). These factors may all contribute to varying extents to the significant decrease in virulence of the FpCBS deletion strain. The findings have shown that FpCBS is important for much more than sulphur metabolism and HS synthesis. However, its role in virulence highlights its potential as a novel target for developing strategies to control wheat crown rot.
从小麦根腐病菌（Fusarium pseudograminearum）中鉴定出一种胱硫醚β-合酶（CBS）基因FpCBS。FpCBS在分生孢子形成和感染早期高度表达。与野生型和FpCBS互补菌株相比，FpCBS缺失菌株具有相似的菌丝形态和生长速率，但分生孢子形成减少。在培养过程中，FpCBS缺失菌株表现出广泛的变化，包括高丝氨酸水平降低、含硫氨基酸变化以及1207种差异表达蛋白。缺失菌株还表现出脱氧雪腐镰刀菌烯醇（DON）产量降低、玻璃纸穿透能力降低、抗氧化能力降低，以及菌丝铁含量增加、对过氧化氢的敏感性增加和脂质过氧化增加。在感染过程中，ΔFpcbs菌株对小麦的毒力减弱，穿透结构减少，并且宿主防御反应更强，小麦表皮细胞壁增厚，活性氧积累更多。对感染叶片的转录组分析表明，与野生型菌株相比，FpCBS缺失菌株中有1954个差异表达基因。这包括硫代谢、抗氧化防御、植物细胞壁降解酶和单端孢霉烯族毒素产生相关的基因。FpCBS不仅在硫代谢和高丝氨酸产生中起关键作用，而且对广泛的真菌功能也很重要，包括铁稳态、霉菌毒素产生和发育（分生孢子形成和穿透结构）。这些因素可能都在不同程度上导致了FpCBS缺失菌株毒力的显著下降。研究结果表明，FpCBS的重要性远不止于硫代谢和高丝氨酸合成。然而，它在毒力方面的作用突出了其作为开发控制小麦根腐病策略新靶点的潜力。
