VdOGDH is involved in energy metabolism and required for virulence of Verticillium dahliae

• Published in: Current genetics 2020-04, Vol.66 (2), p.345-359
• Main Authors: Li, Xiaokang, Su, Xiaofeng, Lu, Guoqing, Sun, Guoqing, Zhang, Zhuo, Guo, Huiming, Guo, Ning, Cheng, Hongmei
• Format: Article
• Language: English
• Subjects: Biochemistry; Biomedical and Life Sciences; Carbon; Carbon sources; Cell Biology; Chlorosis; Conidia; Cotton; Deletion mutant; Disruption; Energy Metabolism; Fungal Proteins - genetics; Fungal Proteins - metabolism; Fungi; Gene deletion; Gene expression; Gene Expression Regulation, Fungal; Genes; Hydrogen peroxide; Hydrogen Peroxide - metabolism; Hydrogen Peroxide - toxicity; Hyphae; Life Sciences; Melanin; Metabolism; Microbial Genetics and Genomics; Microbiology; Original Article; Oxidation; Oxidative stress; Oxidoreductases - metabolism; Plant Sciences; Plant tissues; Proteomics; Reactive oxygen species; Reactive Oxygen Species - metabolism; Soil microorganisms; Tricarboxylic acid cycle; Vascular tissue; Verticillium - enzymology; Verticillium - metabolism; Verticillium - pathogenicity; Verticillium dahliae; Verticillium wilt; Virulence; Virulence Factors - metabolism
• ISSN: 0172-8083; 1432-0983
• DOI: 10.1007/s00294-019-01025-2

Verticillium dahliae , a soil-borne fungus, can invade plant vascular tissue and cause Verticillium wilt. The enzyme α-oxoglutarate dehydrogenase (OGDH), catalyzing the oxidation of α-oxoglutarate in the tricarboxylic acid cycle (TCA), is vital for energy metabolism in the fungi. Here, we identified the OGDH gene in V. dahliae ( VdOGDH , VDAG_10018) and investigated its function in virulence by generating gene deletion mutants ( ΔVdOGDH ) and complementary mutants ( ΔVdOGDH - C ). When the ΔVdOGDH mutants were supplemented with different carbon sources, vegetative growth on Czapek Dox medium was significantly impaired, suggesting that VdOGDH is crucial for vegetative growth and carbon utilization. Conidia of the ΔVdOGDH mutants were atypically rounded or spherical, and hyphae were irregularly branched and lacked typical whorled branches. Mutants ΔVdOGDH - 1 and ΔVdOGDH - 2 were highly sensitive to H 2 O 2 in the medium plates and had higher intracellular ROS levels. ΔVdOGDH mutants also had elevated expression of oxidative response-related genes, indicating that VdOGDH is involved in response to oxidative stress. In addition, the disruption of VdOGDH caused a significant increase in the expression of energy metabolism-related genes VdICL , VdICDH , VdMDH , and VdPDH and melanin-related genes Vayg1 , VdSCD , VdLAC , VT4HR , and VaflM in the ΔVdOGDH mutants; thus, VdOGDH is also important for energy metabolism and melanin accumulation. Cotton plants inoculated with ΔVdOGDH mutants exhibited mild leaf chlorosis and the disease index was lower compared with wild type and ΔVdOGDH - C strains. These results together show that VdOGDH involved in energy metabolism of V. dahliae , is also essential for full virulence by regulating multiple fungal developmental factors.