Zinc deficiency enhances ozone toxicity in bush beans (Phaseolus vulgaris L. cv. Saxa)

In zinc-deficient bush beans (Phaseolus vulgaris L. cv. Saxa) ozone sensitivity was enhanced compared to plants sufficiently supplied with this nutrient. This was correlated with reduced levels of Cu/ZnSOD activity, but was unrelated to effects of zinc deficiency on transpiration, rates of ethylene formation, ascorbic acid content or levels of MnSOD and ascorbate-dependent peroxidase activities. Thus, these results show that detoxification of superoxide anions by Cu/ZnSOD is important in plant resistance to ozone. Additionally, this also indicates the in vivo formation of superoxide anions when plants are exposed to ozone.