Antioxidant activity, photosynthetic rate, and Spectral mass in bean Plants (Phaseolus vulgaris L.) in Response to Stress Defense Activators

An increase in antioxidant activity is a common response in plants as a defense mechanism against biotic and abiotic stress factors, such response is also generated with the exogenous application of "defense activators", which have negative effects on plant metabolism. In this work, bean plants (Phaseolus vulgaris L.) cv. Pinto Nacional were treated with jasmonic acid (0.5 mM), salicylic acid (2 mM), Trichoderma asperellum (105 spores/ml), and Bacillus pumilus (105 CFU / mL), in order to determine the level of structural and metabolic response of the plants. On the seventh day after the application of the treatments, it was measured the enzymatic activity of catalase (CAT), peroxidase (POX), and superoxide dismutase (SOD). In addition, leaf impressions were taken to measure the stomatal opening and conductance, photosynthetic rate, and the mass spectrum (mass/charge, m/z). The antioxidant activity increased in plants treated with jasmonic acid and T. asperellum, which in turn significantly increased the stomatal opening and conductance, and photosynthetic rate. The mass profile showed that the plants treated with T. asperellum have a greater quantity of masses/charge, of which some had statistically highly significant difference according to the means test Tukey (p <0.05). It is concluded that some defense activators such as jasmonic acid and T. asperellum increase the antioxidant activity, defense response that concurs with the high photosynthetic and metabolic rate in bean plants.