Study On The Efficacy Of Wickerhamomyces Anomalus Against Postharvest Gray Mold And Black Spot Disease Of Cherry Tomatoes And Possible Mechanisms Involved

Gray mold and black spot decay caused by Botrytis cinerea and Alternaria alternata are two of the primary postharvest diseases of cherry tomatoes globally,leading to considerable economic losses.Previously,synthetic fungicides had been widely applied to control postharvest diseases in cherry tomatoes due to their effectiveness and low cost.However,the negative impacts of synthetic fungicides lead to research of more interesting alternatives to control postharvest diseases in fruits.Recently,the use of biological control agents was widely reported as promise to protect the fruits and increase the net value of crops.The current study aimed to investigate the potentiality of antagonistic yeast Wickerhamomyces anomalus against gray mold and black spot diseases in cherry tomatoes.Additionally,several possible mechanisms involved were also investigated.The output of this study can provide theoretical reference for the practical application of antagonistic yeasts in the biological control of postharvest diseases of cherry tomatoes.The results of this study were as follows:1.W.anomalus inhibited the growth of gray mold and black spot diseases of cherry tomatoes in concentration dependent manner.Furthermore,W.anomalus successfully reduced the natural decay of cherry tomatoes without affecting their quality parameters after 14 days of storage.W.anomalus was able to adapt,proliferate,and reproduce to a high number during storage period at 20 °C and 4 °C,indicating that W.anomalus could compete for nutrients and space with the pathogens in the wound or on the surface of cherry tomatoes.Additionally,W.anomalus significantly controlled the spore germination and germ tube elongation of B.cinerea and A.alternata in vitro,respectively.2.W.anomalus could enhance the defense-related enzyme activities in cherry tomatoes,including polyphenoloxidase(PPO),peroxidase(POD),catalase(CAT),phenylalanine ammonialyase(PAL),ascorbate peroxidase(APX)and chitinase(CHI),and reduce the content of malondialdehyde(MDA)of cherry tomatoes.Ultimately,the application of W.anomalus induced the disease resistance ability of cherry tomatoes.3.Based on transcriptome technology,W.anomalus could up-regulate genes which have essential roles in fruit disease defense.These genes may help the fruits to enhance the enzyme activities in cherry tomatoes,improve the nutritional values of cherry tomatoes,synthesize the regulatory molecules in plant growth and development as well as plant disease response,increase the defense and oxidation resistance of the fruit during and after harvesting,and trigger ROS induced resistance in cherry tomatoes.