PROLINE LEVELS IN COMMON BEAN cv.'BRSMG MADREPEROLA' ON TROPICAL SOILS CONTAMINATED WITH MERCURY

摘要

Mercury is one of the most problematic elements due to its high toxicological risk. The dynamics of Hg in soils depends on the solubility and adsorption on the organic and mineral phases. The clay content is one of the most relevant attributes that influence Hg sorption. This metal can be absorbed rapidly and leads to changes in the physiology and concentration of many metabolites in the plant. Among these disorders, it can be observed a significant change in the proportions of amino acids and frequently increase in the concentration of proline promoted by proteins hydrolysis. Proline acts as osmoprotectant and also controling reactive oxygen species (ROS). On the other hand, the increase in the proline content can affect the vegetal metabolism, altering the water potential of the leaves.It is important to evaluate the effect of Hg on cultivated plants, emphasizing on highly consumed food crops as common bean (Phaseolus vulgaris L.). "Carioca" bean represents 79% of the consumption of this grain in Brazil. The BRSMG Madreperola cultivaris highly favored due to its high quality, semi-precocious cycle (85 days). This work aims to study the effects of Hg on proline production in cv. BRSMG Madreperola at the beginning of the crop cycle on two tropical soils.