Hanseniaspora uvarum enhanced with trehalose induced defense-related enzyme activities and relative genes expression levels against Aspergillus tubingensis in table grapes

In this study, the activitiesof defense-related enzymes andthose involved in reactive oxygen species (ROS) and their corresponding genes coding for PPO, APX, CHI, PAL and CAT in response to Hanseniaspora uvarum and Hanseniaspora uvarum harvested from NYDB supplemented with 2% w/v trehalose in nutrient yeast dextrose broth (NYDB) were investigated. Conventional methods and qRT-PCR were used to perform defense-related enzyme activities and relative genes expression respectively. The results indicated that H. uvarum enhanced with 2% w/v trehalose demonstrated biocontrol efficacy against Aspergillus tubingensisin grapes.Furthermore, it was noticed that H. uvarum supplemented with 2% w/v trehalose in NYDB had a significantly effect on the induction of defense-related genes expression andenzyme activities compared to the control, 2% w/v trehalose and H. uvarumafter storage at 20 °C for 72 h. CAT relative gene expression level in grapes treated with H. uvarum supplemented with 2% w/v trehalose was the highest with 23-fold increase compared to the control. These results suggested that H. uvarum pretreated with trehalose up-regulatedthe defense-relatedgenes expression and enzyme activitiesin the grapes. These findings indicated that, the application of H. uvarum harvested from NYDB supplemented with 2% w/v trehalose enhanced the defense-related mechanism of grapes against A. tubingensis.