Preharvest hormetic doses of UV‐C radiation can decrease the susceptibility of tomato leaves to Botrytis cinerea L. infection. UV‐C light treatments have been shown to be very effective for reducing disease development in several species, including tomato (Solanum lycopersicum L.). Treating cultivated tomato plants with UV‐C light is of interest not only because of the disinfecting effects of UV‐C light but also because of its ability to stimulate plant defences (SDP) against diseases, provided that the applied doses are high enough to be effective while low enough to prevent deleterious effects. In the present study, the effects of UV‐C light on plants were evaluated by biochemical analyses, including analyses of the activities of antioxidant enzymes and phenylalanine lyase (PAL); the concentration of malondialdehyde (MDA), an indicator of membrane integrity; and chlorophyll fluorescence parameters, such as the maximum quantum efficiency of photosystem II (FV/FM) and the Strasser performance index (PI). In this work, treatments with single doses of 0.85 kJ/m² of UV‐C light were found to significantly increase plant defences against B. cinerea, reducing the affected leaf area by 51% compared to the affected area of control plants. This decrease in susceptibility was associated with increased PAL activity and the amount of bound phenolics compared to levels in control plants (not treated with UV‐C).

中文翻译：

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UV-C 光的刺激剂量降低了番茄植物对灰葡萄孢菌感染的易感性

收获前刺激剂量的 UV-C 辐射可以降低番茄叶子对灰葡萄孢菌感染的易感性。UV-C 光处理已被证明可以非常有效地减少多种物种的疾病发展，包括番茄 (Solanum lycopersicum L.)。用 UV-C 光处理栽培番茄植物很有趣，不仅因为 UV-C 光的消毒作用，而且因为它能够刺激植物防御 (SDP) 对抗疾病，前提是应用的剂量足够高有效而足够低以防止有害影响。在本研究中，通过生化分析评估了 UV-C 光对植物的影响，包括抗氧化酶和苯丙氨酸裂解酶 (PAL) 的活性分析；丙二醛 (MDA) 的浓度，膜完整性指标；和叶绿素荧光参数，例如光系统 II 的最大量子效率 (FV/FM) 和 Strasser 性能指数 (PI)。在这项工作中，发现单剂量 0.85 kJ/m² 的 UV-C 光处理可显着提高植物对 B. cinerea 的防御能力，与对照植物的受影响面积相比，受影响的叶面积减少了 51%。与对照植物（未用 UV-C 处理）相比，这种敏感性的降低与 PAL 活性和结合酚类物质的数量增加有关。发现 85 kJ/m² 的 UV-C 光可显着提高植物对 B. cinerea 的防御能力，与对照植物的受影响面积相比，受影响的叶面积减少了 51%。与对照植物（未用 UV-C 处理）相比，这种敏感性的降低与 PAL 活性和结合酚类物质的数量增加有关。发现 85 kJ/m² 的 UV-C 光可显着提高植物对 B. cinerea 的防御能力，与对照植物的受影响面积相比，受影响的叶面积减少了 51%。与对照植物（未用 UV-C 处理）相比，这种敏感性的降低与 PAL 活性和结合酚类物质的数量增加有关。