Effect of cadmium on phenolic compounds, antioxidant enzyme activity and oxidative stress in blueberry (Vaccinium corymbosum L.) plantlets grown in vitro.

Abstract Cadmium (Cd 2+ ) can affect plant growth due to its mobility and toxicity. We evaluated the effects of Cd 2+ on the production of phenolic compounds and antioxidant response of Vaccinium corymbosum L. Plantlets were exposed to Cd 2+ at 50 and 100 µM for 7, 14 and 21 days. Accumulation of malondialdehyde (MDA), hydrogen peroxide (H 2 O 2 ) and the antioxidant enzyme SOD was determined. The profile of phenolic compounds was evaluated using LC-MS. The antioxidant activity was measured using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and the ferric reducing antioxidant power test (FRAP). Cd 2+ increased the content of MDA, with the highest increase at 14 days. The presence of Cd 2+ resulted in changes in phenolic compounds. The main phenolic compound found in blueberry plantlets was chlorogenic acid, whose abundance increased with the addition of Cd 2+ to the medium. The changes in the composition of phenolic compounds showed a positive correlation with the antioxidant activity measured using FRAP. Our results suggest that blueberry plantlets produced phenolic compounds with reducing capacity as a selective mechanism triggered by the highest activity of Cd 2+ .