Study on the Inhibitory Activity and Mechanism of Imidazole Ethanol Derivatives against Rice Bacterial Leaf Blight

This study designed and synthesized 33 novel imidazole ethanol derivatives and evaluated their efficacy against plant bacterial diseases. Most compounds exhibited excellent antibacterial activity. Particularly, compound D11 showed potent in vitro activity against Xanthomonas oryzae pv oryzae (EC50 = 0.51 μg/mL), surpassing bismerthiazol (EC50 = 3.84 μg/mL). In vivo, D11 effectively controlled rice bacterial leaf blight, with protective and curative effects of 82.8% and 73.1% at 200 μg/mL, both exceeding those of bismerthiazol (56.1% and 52.2%). Mechanistic investigations demonstrated that D11 induces elevated levels of reactive oxygen species, suppresses and compromises the cellular integrity of Xoo, and concurrently downregulates the expression of associated virulence factors, thereby implying a potential multitarget mechanism of action. Notably, D11 exhibits favorable selectivity toward nontarget organisms (earthworms and silkworms). These findings highlight D11 as a promising, environmentally friendly, and highly effective candidate for managing rice bacterial leaf blight.