Stimulating crops to cope with various stressful conditions is an increasingly interesting strategy, even more so when this process is done through seed or seedling priming, since it is simpler and cheaper. The use of UV-A radiation for this purpose can be a viable, economical and environmentally friendly alternative. That is why the aim of this study was to evaluate if seedling priming with UV-A radiation is capable to help tomato and bell pepper plants tolerate water stress. For this, an experiment was carried out in both crop plants, where UV-A radiation was applied directly on the seedlings prior to transplanting on a single occasion, and for two hours. The crops were developed both in optimal water conditions and under water stress conditions. The results obtained show that priming with UV-A decreased the negative effects of water stress in tomato, increased fruit yield by 24.5% and root dry biomass by 46% compared to the stressed control. UV-A priming increased the proline content 294% when there was no stress, and 164% under water stress. Moreover, phenolic compounds were increased by UV-A priming under water stress. In bell pepper, priming with UV-A increased root dry biomass 26% compared to stressed control, but there were no differences in fruit yield. UV-A priming increased 68% more MDA when there was no stress, while under water stress increased 34%. In addition, UV-A priming increased chlorophyll content under water stress. Seedling priming with UV-A radiation can be an efficient strategy to induce tolerance to water stress in agricultural crops, with the great advantage that it is an easy-to-apply and environmentally friendly technology.

中文翻译：

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UV-A 辐射引发幼苗可在水分胁迫下诱导番茄和甜椒植物的积极反应

刺激作物应对各种压力条件是一种越来越有趣的策略，当这个过程通过种子或幼苗引发完成时更是如此，因为它更简单、更便宜。为此目的使用 UV-A 辐射可能是一种可行、经济且环保的替代方案。这就是为什么本研究的目的是评估用 UV-A 辐射引发幼苗是否能够帮助番茄和甜椒植物耐受水分胁迫。为此，我们在两种作物上进行了一项实验，在移植前将 UV-A 辐射直接应用于幼苗，一次持续两个小时。这些作物是在最佳水分条件和水分胁迫条件下生长的。获得的结果表明，与胁迫对照相比，UV-A 引发减少了番茄水分胁迫的负面影响，果实产量增加了 24.5%，根干生物量增加了 46%。当没有胁迫时，UV-A 引发使脯氨酸含量增加 294%，在水分胁迫下增加 164%。此外，在水分胁迫下，酚类化合物会因 UV-A 引发而增加。在灯笼椒中，与胁迫对照相比，用 UV-A 引发的根干生物量增加了 26%，但果实产量没有差异。在没有压力的情况下，UV-A 引发的 MDA 增加了 68%，而在水分压力下则增加了 34%。此外，UV-A 引发在水分胁迫下增加了叶绿素含量。用 UV-A 辐射进行幼苗引发是一种有效的策略，可以诱导农作物对水分胁迫的耐受性，其最大优点是它是一种易于应用且环境友好的技术。