Induction of resistance to spot blotch in Hordeum vulgare L. by exogenous methyl jasmonate

Abstract [Objective] The study aims to investigate the differential efficacy of anti-leaf spot in barley (Hordeum vulgare L.) of various concentrations of exogenous methyl jasmonate (MeJA) and understand the underlying mechanisms, thereby providing a foundation for the application of MeJA in controlling barley leaf spot. [Methods] We used ‘Mengpimai 3’ (MP3) seedlings as materials and conducted three different treatments: Inoculating the barley leaves with sterile water without any Bipolaris sorokiniana (the causal agent of the disease), inoculating the barley leaves with sterile water after treatment, and treating the barley leaves with different concentrations (0.5, 1.0, 1.5, 2.0, 2.5 mmol/L) of methyl jasmonate (MeJA) before inoculation with the pathogen. The disease incidence was investigated at the three-leaf stage based on disease index to determine the optimal MeJA concentration. We measured antioxidant enzyme activities, anti-disease-related enzyme activities, malondialdehyde, proline, soluble sugar,