Distinct physiological and metabolic reprogramming by highbush blueberry (Vaccinium corymbosum) cultivars revealed during long‐term UV‐B radiation

Despite the Montreal protocol and the eventual recovery of the ozone layer over Antarctica, there are still concerns about increased levels of ultraviolet‐B (UV‐B) radiation in the Southern Hemisphere. UV‐B induces physiological, biochemical and morphological stress responses in plants, which are species‐specific and different even for closely related cultivars. In woody plant species, understanding of long‐term mechanisms to cope with UV‐B‐induced stress is limited. Therefore, a greenhouse UV‐B daily course simulation was performed for 21 days with two blueberry cultivars (Legacy and Bluegold) under UV‐BBE irradiance doses of 0, 0.07 and 0.19 W m−2. Morphological changes, photosynthetic performance, antioxidants, lipid peroxidation and metabolic features were evaluated. We found that both cultivars behaved differently under UV‐B exposure, with Legacy being a UV‐B‐resistant cultivar. Interestingly, Legacy used a combined strategy: initially, in the first week of exposure its photoprotective compounds increased, coping with the intake of UV‐B radiation (avoidance strategy), and then, increasing its antioxidant capacity. These strategies proved to be UV‐B radiation dose dependent. The avoidance strategy is triggered early under high UV‐B radiation in Legacy. Moreover, the rapid metabolic reprogramming capacity of this cultivar, in contrast to Bluegold, seems to be the most relevant contribution to its UV‐B stress‐coping strategy.