Abstract：
Rice bacterial leaf blight and rice bacterial leaf streak have induced tremendous damage to production of rice worldwide. To discover an effective novel antibacterial agent, a series of novel trans-resveratrol (RSV) derivatives containing 1,3,4-oxadiazole and amide moieties were designed and synthesized for the first time. Most of them showed excellent antibacterial activities against Xanthomonas oryzae pv oryzicola and Xanthomonas oryzae pv oryzae. Especially, compound J12 had the best inhibitory with the half-maximal effective concentration values of 4.2 and 5.0 mg/L, respectively, which were better than that of RSV (63.7 and 75.4 mg/L), bismerthiazol (79.5 and 89.6 mg/L), and thiodiazole copper (105.4 and 112.8 mg/L). Furthermore, compound J12 had an excellent control effect against rice bacterial leaf streak and rice bacterial leaf blight, with protective activities of 46.2 and 42.1% and curative activities of 44.5 and 41.7%, respectively. Preliminary mechanisms indicated that compound J12 could not only remarkably decrease biofilm formation, extracellular polysaccharide production, and the synthesis of extracellular enzymes but also destroy bacterial cell surface morphology, thereby reducing the pathogenicity of bacteria. In addition, compound J12 could increase the activity of defense-related enzymes and affect the expression of multiple pathogenic-related genes including plant-pathogen interaction, the MAPK signaling pathway, and phenylpropanoid biosynthesis, and this could improve the defense of rice against rice bacterial leaf streak infection. The present work indicates that the RSV derivatives can be used as promising candidates for the development of antibacterial agents.
摘要：
水稻细菌性叶枯病和水稻细菌性条斑对世界范围内的水稻生产造成了巨大的危害。为了发现一种有效的新型抗菌剂，首次设计并合成了一系列含有1,3,4-恶二唑和酰胺部分的新型反式白藜芦醇（RSV）衍生物。它们中的大多数对米黄单胞菌和米黄单胞菌均表现出优异的抗菌活性。尤其是,化合物J12抑菌效果最好,半数最大有效浓度为4.2和5.0mg/L,分别,优于RSV（63.7和75.4mg/L），双甲噻唑（79.5和89.6mg/L），和噻二唑铜（105.4和112.8mg/L）。此外，化合物J12对水稻细菌性条纹和水稻细菌性叶枯病具有良好的防治效果，保护活性为46.2%和42.1%，治疗活性为44.5%和41.7%，分别。初步机制表明,化合物J12不仅能显著降低生物膜的形成,胞外多糖生产，和胞外酶的合成，但也破坏细菌细胞表面的形态，从而降低细菌的致病性。此外,化合物J12可以增加防御相关酶的活性，并影响多种致病相关基因的表达，包括植物-病原体相互作用，MAPK信号通路，和苯丙素生物合成，这可以提高水稻对水稻细菌性条纹感染的防御能力。目前的工作表明，RSV衍生物可以用作开发抗菌剂的有希望的候选物。
