Evaluation the Activity of Peroxidase and Catalase Enzymes and the Expression Level of PR1 and PR8 Genes in Apple Fruit following Brown Rot (Monilinia laxa) disease

Apple is one of the most important economic products of Iran and the world. Apple brown rot disease (Monilinia laxa) is one of the important diseases that causes yield loss in pre-harvest and post-harvest stages. In this research, the amount of changes in some defense compounds of apple fruit, including peroxidase and catalase enzymes, following inoculation with M. laxa was assessed. Extraction and measurement of peroxidase and catalase enzymes were done at 0, 3, 6, 9 and 12 days post inoculation with M. laxa. Also, in this study, the changes in the expression of PR1 and PR8 genes in response to brown rot disease in apple fruit was recorded at 12, 24, 48 and 96 hours along with controls. The results of the analysis of variance of resistance genes expression at different time points were significant. After 48 hours, the expression of PR1 and PR8 genes was observed to be the highest compared to the control. The expression of PR1 and PR8 genes was observed to be 3 and 8 times that of the control, respectively. In this research, the expression of PR1 and R8 genes was assessed for the first time following M. laxa inoculation in apples. Results of the present study showed that reseistance genes as well as the antioxidant enzymes can help to improve resistance against apple brown rot disease as an important storage pathogens for long-term storage.