The presence of Microlobius foetidus cause changes in the antioxidant defense of Urochloa decumbens?

Abstract

Urochloa decumbens (Stapf) R. D. Webster (Poaceae) is an exotic species with has spread rapidly through the Cerrado area of Pantanal, Mato Grosso do Sul, Brazil. It has covered the soil aggressively turning it into cultivated pastures. Thus, it has become a challenge to protect native areas due its capacity of exclusion of native species. It has been observed that Microlobius foetidus (Jacq.) M.Sousa & G.Andrade species (Fabaceae) shows a dominant pattern over the development of U. decumbens. This work shows that M. foetidus interfere on the natural growth of U. decumbens within 10 m ratio. Between 15 and 20 m, it was observed an increase of Importance Value index (IVI) and Relative cover (RC) values. It was also observed a variation on the antioxidant defense system of U. decumbens within 10m ratio from M. foetidus. The enzymes superoxide dismutase, catalase and peroxidase present higher levels of activity then those found for glutathione reductase. This data indicates that M. foetidus may have an effect on U. decumbens, increase the activity of antioxidant enzymes. This effect probably happens as means to neutralize the toxic effects of the oxygen generated due to the presence of allelochemicals, which increases oxidative stress.Keywords: antioxidant enzymes, signal grass, garlic stick, competition. A presença de

Physiological and Biochemical Alterations of Urocholoa brizantha Submitted to Water Deficit and Silicate Fertilization

“…Plants added with silicon showed increased activity of SOD and CAT enzymes demonstrating the Si main role as an inducer of enzymatic activation in Urocholoa decumbens plants in which an increased antioxidant activity in response to oxidative stress counterbalanced the increase in ROS levels (Silva et al, 2015). However, in our study, the activity of SOD decreased (Table 5) under conditions of water deficity and silicon application, while CAT activity increased under these conditions.…”