Effect of Heavy Metals on the Morphological and Physiological Responses of the Torro Plus Variant of Zea mays

This study evaluates the impact of heavy metals (zinc, copper and cadmium) on the development and metabolic responses of the maize (Zea mays) variety “Torro Plus”. Seeds were cultivated on MS medium enriched with progressively higher concentrations of heavy metals (50, 100 and 150 μM), and plants were analyzed after 21 days. The results show a significant reduction in morphological parameters, notably an 87.28% decrease in the fresh weight of aerial parts and a 69.93% decrease in the fresh weight of roots under 150 μM of Cd. Chlorophyll a, b and total content also decreased drastically, reaching a maximum reduction of 74.31% under Cd (150 μM). In contrast, secondary metabolites such as proline and flavonoids increased, with a maximum proline accumulation of 0.71 mg/g under Cu (150 μM) and a flavonoid concentration reaching 176.33 mg/g under Cu (100 μM). These results show mechanisms of adaptation to stress, notably the accumulation of flavonoids and proline, while highlighting the increased toxicity of cadmium at high doses. These data are promising for applications in phytoremediation and sustainable agriculture. This study provides important data on the physiological and biochemical responses of plants to heavy metals and opens up prospects for phytoremediation applications.