Tobacco mosaic virus (TMV), as one of the most traditional and extensive biological stresses, poses a serious threat to plant growth and development. In this work, a series of 1-phenyl/tertbutyl-5-amino-4-pyrazole oxadiazole and arylhydrazone derivatives was synthesized. Bioassay evaluation demonstrated that the title compounds (P₁–P₁₈) without a “thioether bond” lost their anti-TMV activity, while some of the ring-opening arylhydrazone compounds exhibited superior in vivo activity against TMV in tobacco. The EC₅₀ value of title compound T₈ for curative activity was 139 μg/mL, similar to that of ningnanmycin (NNM) (EC₅₀ = 152 μg/mL). Safety analysis revealed that compound T₈ had no adverse effects on plant growth or seed germination at a concentration of 250 μg/mL. Morphological observation revealed that compound T₈ could restore the leaf tissue of a TMV-stressed host and the leaf stomatal aperture to normal. A mechanism study further revealed that compound T₈ not only restored the photosynthetic and growth ability of the damaged host to normal levels but also enhanced catalase (CAT) activity and reduced the content of malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) in the damaged host, thereby reducing the oxidation damage to the host. TMV–green fluorescent protein (GFP) experiments further demonstrated that compound T₈ not only slowed the transmission speed of TMV in the host but also inhibited its reproduction. All of the experimental results demonstrated that compound T₈ could reduce the oxidative damage caused by TMV stress and regulate the photosynthetic ability of the host, achieving the ability to repair damage, to make the plant grow normally.

中文翻译：

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修复烟草花叶病毒胁迫引起的宿主损伤：新型恶二唑和芳基腙衍生物的设计、合成及机理研究


烟草花叶病毒(TMV)作为最传统、最广泛的生物胁迫之一，对植物的生长发育构成严重威胁。本工作合成了一系列1-苯基/叔丁基-5-氨基-4-吡唑恶二唑和芳基腙衍生物。生物测定评价表明，不含“硫醚键”的标题化合物（P ₁ –P ₁₈ ）失去了抗TMV活性，而一些开环芳基腙化合物表现出优异的抗TMV活性。体内针对烟草中 TMV 的活性。标题化合物 T ₈ 治疗活性的 EC ₅₀ 值为 139 μg/mL，与宁南霉素 (NNM) 相似 (EC ₅₀ = 152 μg /毫升）。安全性分析显示，化合物T ₈ 在250 μg/mL浓度下对植物生长或种子萌发无不良影响。形态学观察表明，化合物T ₈ 可以使TMV胁迫宿主的叶片组织和叶片气孔孔径恢复正常。机理研究进一步揭示，化合物T ₈ 不仅使受损宿主的光合和生长能力恢复到正常水平，而且增强过氧化氢酶（CAT）活性，降低丙二醛（MDA）和过氧化氢的含量(H ₂ O ₂ ) 存在于受损的宿主中，从而减少氧化对宿主的伤害。 TMV-绿色荧光蛋白（GFP）实验进一步证明，化合物T ₈ 不仅减慢了TMV在宿主体内的传播速度，而且抑制了其繁殖。所有实验结果表明，化合物T ₈ 能够减轻TMV胁迫造成的氧化损伤，调节寄主的光合能力，达到修复损伤的能力，使植物正常生长。