Iron and zinc supplies mitigate cadmium toxicity in micropropagated banana (Musa spp.)

Cadmium (Cd) is a toxic heavy metal that negatively affects plant growth and physiology. Plants display multiple changes in physiological and biochemical events to cope with Cd toxicity. Iron (Fe) and zinc (Zn) resulted effective for enhancing plant growth under Cd stress. This paper is the first to study the interaction of Fe and Zn and their behavior with Cd in banana. Fe and Zinc at two concentrations (200 and 500 μM) were used in modulating Cd toxicity (500 μM) of micropropagated banana shoots. The results showed that Cd significantly decreased water content, photosynthetic pigments, flavonoids and total protein content. Conversely, ascorbic acid, proline, malondialdehyde and non-protein thiol protein concentrations were increased. Application of Fe and Zn at different concentrations mitigated Cd toxicity by maintaining chlorophyll and carotenoids, non-enzymatic antioxidants, total protein and non-protein thiol, suggesting a role of Fe and Zn in mediating banana shoots defense responses under Cd toxicity in vitro. Key Message This paper is the first to illustrate the interaction of iron and zinc with cadmium in banana, and it provides experimental evidence for the remarkable role of iron and zinc in the regulation of Cd stress in banan ( Musa spp.) under in vitro condition.