Department of Agriculture, Food and Environment, University of Pisa, via del Borghetto 80, 56124, Pisa, Italy; Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Muthgasse 18, 1190, Vienna, Austria.
Department for Sustainable Food Process, Università Cattolica del Sacro Cuore, Via Emilia Parmense, 84, 29122, Piacenza, Italy.
Plant Physiol Biochem. 2019 Feb;135:511-519. doi: 10.1016/j.plaphy.2018.11.009. Epub 2018 Nov 12.
Ultraviolet-B (UVB) radiation impacts the plant behaviour in many ways, including modifying their secondary metabolism. Although several studies have quantified the UV-B effects on phenolic composition, most of them focused on leaves or investigated a limited amount of phenolics. The present work aimed to investigate the phenolic changes after two postharvest UV-B treatments, 10 and 60 min (1.39 kJ m and 8.33 kJ m, respectively), on peach (Prunus persica cv Fairtime) fruit with a non-targeted, whole profiling approach, and targeted gene expression analysis on skin. After both UV-B exposures, peach fruit were harvested at 24 and 36 h for "phenol-omics" analysis, while additional 6 h and 12 h recovery times were used for gene expression analysis. Our results revealed that both UV-B exposures resulted in a decrease of several phenolic compounds, such as anthocyanins, after 24 h from the exposure. In contrast, the expression of the UV-B signalling components, the phenylpropanoid biosynthesis genes and their transcriptional regulators increased 6 h after the treatment, mostly with a UV-B-dose dependent behaviour, preceding an accumulation of most phenolics in both the UV-B treatments at 36 h compared to 24 h. Orthogonal projections to latent structures discriminant analysis (OPLS-DA) revealed that flavonoids, particularly anthocyanins, were the main phenolic subclasses accumulated after UV-B exposure.
紫外线-B（UVB）辐射以多种方式影响植物行为，包括改变其次生代谢。尽管有几项研究已经量化了 UV-B 对酚类成分的影响，但大多数研究都集中在叶片上，或者只调查了有限数量的酚类物质。本研究旨在通过非靶向、全谱分析方法，研究两种采后 UV-B 处理（分别为 10 和 60 分钟，1.39 kJ m 和 8.33 kJ m）对桃（Prunus persica cv Fairtime）果实酚类物质的变化，并对果皮进行靶向基因表达分析。在两次 UV-B 暴露后，桃果实分别在 24 和 36 小时进行“酚类组学”分析，同时在 6 和 12 小时恢复时间进行基因表达分析。我们的研究结果表明，两种 UV-B 暴露都导致暴露后 24 小时内几种酚类化合物，如类黄酮的含量降低。相比之下，UV-B 信号成分、苯丙素生物合成基因及其转录调节剂的表达在处理后 6 小时增加，主要表现为与剂量有关的行为，在 36 小时时，两种 UV-B 处理下的大多数酚类物质的积累均高于 24 小时。正交投影到潜在结构判别分析（OPLS-DA）显示，类黄酮，特别是花青素，是 UV-B 暴露后积累的主要酚类亚类。
