Li Peiqian, Pu Xiaoming, Feng Baozhen, Yang Qiyun, Shen Huifang, Zhang Jingxin, Lin Birun
Key Laboratory of New Techniques for Plant Protection in Guangdong, Institute of Plant Protection, Guangdong Academy of Agricultural Sciences Guangzhou, China ; Department of Life Sciences, Yuncheng University Yuncheng, China ; Department of Plant Pathology, College of Agriculture, Guangxi University Nanning, China.
Key Laboratory of New Techniques for Plant Protection in Guangdong, Institute of Plant Protection, Guangdong Academy of Agricultural Sciences Guangzhou, China.
Front Plant Sci. 2015 May 6;6:312. doi: 10.3389/fpls.2015.00312. eCollection 2015.
Velvet genes play critical roles in the regulation of diverse cellular processes. In current study, we identified the gene FocVel1, a homolog of Fusarium graminearum VelA, in the plant pathogenic fungus F. oxysporum f. sp. cucumerinum. This pathogen causes the destructive disease called cucumber Fusarium wilt (CFW), which severely affects the production and marketing of this vegetable worldwide. Transcript analyses revealed high expression of FocVel1 during conidiophore development. Disruption of the FocVel1 gene led to several phenotypic defects, including reduction in aerial hyphal formation and conidial production. The deletion mutant ΔFocVel1 showed increased resistance to both osmotic stress and cell wall-damaging agents, but increased sensitivity to iprodione and prochloraz fungicides, which may be related to changes in cell wall components. In the process of biofilm formation in vitro, the mutant strain ΔFocVel1 displayed not only a reduction in spore aggregation but also a delay in conidial germination on the polystyrene surface, which may result in defects in biofilm formation. Moreover, pathogenicity assays showed that the mutant ΔFocVel1 exhibited impaired virulence in cucumber seedlings. And the genetic complementation of the mutant with the wild-type FocVel1 gene restored all the defects of the ΔFocVel1. Taken together, the results of this study indicated that FocVel1 played a critical role in the regulation of various cellular processes and pathogenicity in F. oxysporum f. sp. cucumerinum.
天鹅绒基因在多种细胞过程的调控中发挥着关键作用。在当前研究中，我们在黄瓜枯萎病菌（F. oxysporum f. sp. cucumerinum）中鉴定出了FocVel1基因，它是禾谷镰刀菌VelA的同源物。这种病原菌会引发一种名为黄瓜枯萎病（CFW）的毁灭性病害，严重影响全球范围内这种蔬菜的生产和销售。转录分析显示FocVel1在分生孢子梗发育过程中高表达。FocVel1基因的破坏导致了几个表型缺陷，包括气生菌丝形成和分生孢子产生减少。缺失突变体ΔFocVel1对渗透胁迫和细胞壁损伤剂均表现出增强的抗性，但对异菌脲和咪鲜胺杀菌剂的敏感性增加，这可能与细胞壁成分的变化有关。在体外生物膜形成过程中，突变菌株ΔFocVel1不仅孢子聚集减少，而且在聚苯乙烯表面分生孢子萌发延迟，这可能导致生物膜形成缺陷。此外，致病性分析表明突变体ΔFocVel1在黄瓜幼苗中的致病力受损。用野生型FocVel1基因对突变体进行遗传互补恢复了ΔFocVel1的所有缺陷。综上所述，本研究结果表明FocVel1在黄瓜枯萎病菌各种细胞过程和致病性的调控中发挥着关键作用。
