Title Involvement of Alternative Oxidase in the Regulation of Growth, Development, and Resistance to Oxidative Stress of Sclerotinia sclerotiorum
Author Ting Xu1,2, Fei Yao1,2, Wu-Sheng Liang1,2*, Yong-Hong Li3, Dian-Rong Li3, Hao Wang3, and Zheng-Yi Wang1,2
Address 1Institute of Biotechnology, College of Agriculture and Biotechnology, Zijingang Campus, Zhejiang University, Hangzhou 310058, P. R. China, 2State Key Laboratory of Rice Biology, Hangzhou 310058, P. R. China, 3Hybrid Rapeseed Research Center of Shaanxi Province, Dali 715105, P. R. China
Bibliography Journal of Microbiology, 50(4),594-602, 2012,
DOI
Key Words Sclerotinia sclerotiorum, alternative oxidase, mitochondrial respiratory chain, hydrogen peroxide, oxidative stress
Abstract Sclerotinia sclerotiorum is a cosmopolitan, filamentous, fungal pathogen that can cause serious disease in many kinds of crops. Alternative oxidase is the terminal oxidase of the alternative mitochondrial respiratory pathway in fungi and higher plants. We report the presence of this alternative pathway respiration and demonstrate its expression in two isolates of S. sclerotiorum under unstressed, normal culture conditions. Application of salicylhydroxamic acid, a specific inhibitor of alternative oxidase, severely inhibited the mycelial growth of S. sclerotiorum both on potato dextrose agar plates and in liquid culture media. Inhibition of alternative oxidase could influence the growth pattern of S. sclerotiorum, as salicylhydroxamic acid treatment induced obvious aerial mycelia growing on potato dextrose agar plates. Under the treatment with salicylhydroxamic acid, S. sclerotiorum formed sclerotia much more slowly than the control. Treatment with hydrogen peroxide in millimolar concentrations greatly decreased the growth rate of mycelia and delayed the formation of sclerotia in both tested S. sclerotiorum isolates. As well, this treatment obviously increased their alternative pathway respiration and the levels of both mRNA and protein of the alternative oxidase. These results indicate that alternative oxidase is involved in the regulation of growth, development, and resistance to oxidative stress of S. sclerotiorum.