Liu, J., U.S. Department of Agriculture, Agricultural Research Service, WV, United States, Institute of Botany, Chinese Academy of Sciences, Beijing, China
Wisniewski, M., U.S. Department of Agriculture, Agricultural Research Service, WV, United States

Vero, S., Institute Cátedra de Microbiología, Facultad de Química, Universidad de la República, Montevideo, Uruguay
Tian, S., Institute of Botany, Chinese Academy of Sciences, Beijing, China
 

The effect of H2O2-induced oxidative stress on the viability of the yeast antagonist, Cystofilobasidium infirmominiatum, as well as the effect of exogenous glycine betaine (GB) on yeast viability under oxidative stress, was determined. GB treatment improved the tolerance of C. infirmominiatum to oxidative stress. Compared to untreated control yeast cells, GB-treated cells showed less accumulation of reactive oxygen species (ROS) and a lower level of protein oxidation in response to oxidative stress. Additionally, GB-treated yeast exhibited greater biocontrol activity against Penicillium expansum and a faster growth in wounds of apple fruits stored at 25°C compared to the performance of untreated yeast. The activities of antioxidant enzymes, including catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPX) of C. infirmominiatum were elevated by GB treatment. Results indicate that the elicitation of antioxidant response by GB may contribute to improvements in oxidative stress tolerance, population growth in apple wounds, and biocontrol activity of C. infirmominiatum. © 2011.