Pretreatment of cucumber seeds with benzothiadiazole (BTH) induced resistance against damping-off caused by Pythium aphanidermatum

Resistance-inducing compounds represent a novel strategy for managing plant diseases. This study investigated the efficacy of benzothiadiazole (BTH) in mitigating cucumber damping-off disease through seed pretreatment under greenhouse conditions. The expression patterns of defense genes (PR1, PAL1, and LOX) were assessed at multiple time points (0, 24, 48, and 72 h) post-pathogen inoculation via qPCR. Disease index analysis revealed a significant reduction in disease severity in the 100 μg/ml BTH treatment group (43.33% disease index) compared with the untreated control group (100% disease index). Following BTH treatment, rapid and robust upregulation of the LOX and PAL1 genes was observed shortly after inoculation, peaking at 72 h and significantly differing from the control levels. Elevated LOX expression indicated that BTH-induced resistance was mediated through the JA signaling pathway. Conversely, PR1 gene expression did not differ significantly between BTH-treated and control plants. These findings underscore BTH as a promising, straightforward, and environmentally safe approach for managing cucumber damping-off disease. This study contributes insights into plant defense mechanisms and highlights BTH’s potential for use in sustainable agricultural practices aimed at enhancing crop protection and productivity.