Effect of arsenic in soybean plants associated to pathogens and arbuscular mycorrhizae

SPAGNOLETTI F; CHIOCCHIO V.; HERNANDEZ A; CARMONA M; RAÚL LAVADO; BALESTRASSE KB

Congreso; SAIB 2014; 2014

As induced oxidative stress in plants was determined by lipid peroxidation, which remained elevated in leaves. The objective of this work was to evaluate the oxidative stress in soybean plants exposed to arbuscular mycorrhizae (AM), a phytopathogenic fungi and Arsenic. To this end, catalase (CAT), superoxide dismutase (SOD), guayacol peroxidase (GPOX), glutathione reductase (GR) activities and glutathione (GSH) levels were determinated. Plants were grown in pots c ontaining soil:vermiculite (3:1). Rhizophagus intraradices and Macrophomina phaseolina was employed as phytopathogen. Soils were treated with different As concentrations ranging from 0 to 50 mg/ kg substrate. Plant biomass was evaluated and antioxidant response was tested in the leaves. Results here presented demonstrated that an increment in biomass in plants treated with AM and AM + pathogen occurred. Nevertheless, a diminution was observed in plants treated with M. phaseolina. In plants subjected to AM, CAT and GPOX activities as well as GSH levels were enhanced respect to controls. Surprisingly, GR, CAT and SOD activities as well as GSH levels diminished in the presence of phytophogenic fungi. In co-inoculated plants a positive response was observed respect to the result obtained with MA. These results let us assume that the co-inoculation enhances antioxidant defence as well as biomass.