The effects of enhanced UV-B radiation were investigated in the carnivorous plant Pinguicula vulgaris in a field
experiment performed in Abisko, North Sweden (68° 21′ N, 18° 49′ E, 380 m above sea level). Potted plants were
exposed to either ambient or ambient plus supplemental UV-B radiation, simulating a 15% ozone depletion. No
effect was observed on either the epicuticular (external) or cellular (internal) UV absorbing capacity of the leaves.
However, the anthocyanin content was more than doubled by supplemental UV-B radiation. In laboratory
experiments, the anthocyanin rich, UV-B treated leaves were less susceptible to a low temperature/high light
photoinhibitory treatment, as judged by in vivo chlorophyll fluorescence measurements. Yet, this potential benefit
did not considerably affect the growth of the plant in the field (leaf area and dry mass, reproductive dry mass,
flowering frequency, senescence rates, dry mass of winter buds). However, there was a marginally significant
increase in root dry mass and in the root to shoot ratio, which may underlie the significant increase in the nitrogen
content of the leaves. We suggest that P. vulgaris is resistant against UV-B radiation damage and that the possible
negative effects of additional UV-B radiation on the growth of these plants may have been effectively
counterbalanced by the lower risk of photoinhibition, due to the concomitant increase in anthocyanins.