Biochemical reactions of potato plants infected with alternaria under NaCl stress

Potato is exposed to many abiotic and biotic stress factors. With excessive temperature and excessive irrigation, salt accumulation in the soil increases, therefore the destructive effects of biotic stress factors become more severe. In this study, the response of potato plants artificially infected with Alternaria altarnata agent isolated from potato fields was investigated under artificially induced NaCl stress. The study was carried out in four groups with six replications according to the randomized plot design in plants infected with Alternaria agent. These groups consisted of; a) control, b) Alternaria infected plants, c) healthy plants to which 100 mmol L-1 NaCl was applied, d) Alternaria infected plants to which 100 mmol L-1 NaCI was applied. The plants in each group were watered with water and salt solution at 2-3 day intervals for five weeks according to the need. As a result of the applications, chlorophyll, catalase (CAT), jasmonic acid (JA), salicylic acid (SA), protein and peroxidase (POX) analyses were performed from the samples taken from the leaves. While JA, SA, CAT and POX enzyme contents decreased in potato leaves infected with Alternaria compared to plants treated with 100 mmol L-1 NaCl, protein and chlorophyll contents were found to be higher (P<0.05). This study is one of the first to examine the changes in chlorophyll content and antioxidant enzyme levels in potato plants caused by salt stress and Alternaria infection. The findings obtained reveal that salt application increases pathogenic pressure in the plant. Understanding the biochemical responses of the plant to Alternaria under salt stress conditions will contribute significantly to the elucidation of the resistance mechanisms of potato to diseases and the development of effective control strategies.