Department of Chemistry & QOPNA - Organic Chemistry, Natural Products and Food Stuffs, University of Aveiro, Campus Universitário de Santiago 3810-193, Aveiro, Portugal.
Department of Biology, Faculty of Sciences and LAQV/REQUIMTE - Laboratório Associado para a Química Verde/ Rede de Química e Tecnologia, University of Porto, Rua do Campo Alegre 4169-007, Porto, Portugal.
Funct Plant Biol. 2018 Nov;45(12):1233-1240. doi: 10.1071/FP18026.
Climate change scenarios increase the frequency of combined episodes of drought, heat and high UV radiation, particularly in the Mediterranean region where dryland farming of olive (Olea europaea L.) orchards remains a common practice. Nonirrigated olive plants (drought treatment) were subjected to an episode of heat plus UV-B radiation shock (DH+UV-B treatment) for 2 days. After the treatments, plants were allowed to grow under irrigated conditions (recovery). Compared with irrigated plants, drought treatment induced lower relative water content but this status was not aggravated when DH+UV-B shock was applied. Additionally, the effective quantum yield of PSII was similar in the drought-stressed and DH+UV-B treatments. Interestingly, the DH+UV-B treatment produced higher photosynthetic pigment contents than drought-stressed plants. Concerning oxidative status, the DH+UV-B treatment induced similar lipid peroxidation levels and only cell membrane permeability was higher than in drought-stressed plants. On other hand, drought-stressed plants showed higher levels of anthocyanins and proline. Our data suggest that plants grown under dryland conditions modulated some tolerance mechanisms that may prevent cumulative damages by other stressors. Moreover, drought-stressed and DH+UV-B plants were able to recover their physiological performance in a similar way. These data represent an important contribution to understanding how dryland -grown olive plants will cope with climate change.
气候变化情景增加了干旱、高温和高强度紫外线辐射综合事件的发生频率，特别是在地中海地区，那里的旱地橄榄（Olea europaea L.）果园种植仍然是一种常见做法。未灌溉的橄榄植物（干旱处理）经历了 2 天的高温加 UV-B 辐射冲击（DH+UV-B 处理）。处理后，植物在灌溉条件下生长（恢复）。与灌溉植物相比，干旱处理会导致相对水分含量降低，但当施加 DH+UV-B 冲击时，这种情况并没有加剧。此外，PSII 的有效量子产量在干旱胁迫和 DH+UV-B 处理中相似。有趣的是，DH+UV-B 处理产生的光合色素含量高于干旱胁迫植物。关于氧化状态，DH+UV-B 处理诱导的脂质过氧化水平相似，只有细胞膜通透性高于干旱胁迫植物。另一方面，干旱胁迫植物表现出更高水平的花青素和脯氨酸。我们的数据表明，在旱地条件下生长的植物调节了一些耐受机制，这些机制可能防止了其他胁迫因素的累积损害。此外，干旱胁迫和 DH+UV-B 植物能够以相似的方式恢复其生理性能。这些数据为了解旱地生长的橄榄植物将如何应对气候变化提供了重要贡献。
