Relationship between manganese toxicity and waterlogging tolerance in Zea mays L. cv. Saracura

Relação entre a toxicidade de manganês e a tolerância ao alagamento em plantas de Zea mays L. cv. Saracura

ABSTRACT.

The objective of this study was to evaluate the relationship between excess manganese and waterlogging tolerance in 18^th selection cycle Zea mays L. cv. Saracura plants. Maize plants were transferred to plastic receptacles containing solutions with different concentrations of manganese. Leaves and roots were evaluated at the beginning of treatment and after 7, 14, and 21 days for chlorophyll content, biomass production and antioxidant metabolism. Mn was strongly translocated from the roots to the leaves, triggering a decrease in chlorophyll content. Excess Mn promoted an increase in reactive oxygen species that was accompanied by higher levels of antioxidative enzyme activity and lipid peroxidation. Zea mays L. cv. Saracura efficiently sequestered relatively large amounts of Mn in the leaves, with a significant impact on metabolism; however, we did not observe visual symptoms or a large decrease in biomass production.

Keywords:
hypoxia; chlorophyll; oxidative stress