Isoenzymes and Cytochemical Analysis in Tetragonisca angustula and Tetragonisca fiebrigi After Herbicide Contamination

摘要

Changes in the expression of isoenzymes, peptides and nerve cells of T. angustula and T.fiebrigi stingless bees were evaluated after in vitro contamination with Sanson 40SC (nicosulfuron) and 200 Gramoxone* (paraquat) herbicides, and also the use of such bees as bioindicators of the presence of pesticides. After contamination, analyses of changes in expression of isoenzymes esterases (EST), malate dehydrogenase (MDH), superoxide dismutase (SOD) and nerve cells employing CEC (critical electrolyte concentration) were conducted. The herbicide nicosulfuron causes partial inhibition of esterases from T. angustula and T. fiebrigi. The herbicide paraquat promotes total inhibition of esterase activity in T.fiebrigi from the concentration of 1%, and in concentrations of 10% and 100% in T. angustula. The superoxide dismutase isoenzymes showed an increase in their relative activity after contamination with paraquat at 10% and 100% in both species. No changes were observed for MDH and peptides. In the nerve cells there were observed few changes in gene expression after contact with the herbicides. The esterase and superoxide dismutase enzymes present in extracts of T. angustula and T. fiebrigi are sensitive to the presence of nicosulfuron and paraquat, therefore these isoenzymes are potential bioindicators of the presence of these herbicides.