Heat shock-induced resistance increases chitinase-1 gene expression and stimulates salicylic acid production in melon (Cucumis melo L.)

The present study continued previous research to investigate a mechanism involved in heat shock-induced resistance (HSIR) of melon seedlings. HSIR in melon seedlings increased chitinase1 gene expression 12 and 72 h after treatment. Salicylic acid β-d-glucoside and free salicylic acid showed significant accumulation in the leaves post-treatment, 24 and 96 h for SAG; and 96 h for free SA. We found that the treatment of heat shock on the first leaves reduced lesions of gray mold on the untreated second leaves. It was assumed that SAR occurred in HSIR, however it was not as the first mechanism.

► We examine whether HSIR is a SAR mediated mechanism. ► HSIR in first leaves reduce development of melon gray mold in untreated leaves. ► HSIR increased CHI1 gene expression. ► HSIR increased Free salicylic acid and Salicylic acid β-d-glucoside accumulation. ► We assumed that SAR occurred in HSIR, however it was not as the first mechanism.