Physiological and biochemical role of selenium on flavonoids biosynthesis and biological nitrogen fixation of legume plants

Abstract

Selenium (Se) is essential for humans and animals and considered beneficial for plants at low concentration.There is conclusive evidence of Se deficiency in Brazilian soils. Selenium can activate flavonoids biosynthesis in roots of legume plants, increasing chemotaxis between roots and bacteria Rhizobium. Little is known about the role of Se on nodulation of legumine plants. The hypothesis of this work is that Se supply increases the synthesis of flavonoids (daidzein, genistein, kaempferol, quercetin, rutin and naringerin) in roots acting as chemical signal to increase root nodulation by rhizobia, consequently increasing the flow of ureides and antioxidative metabolism in soybean, cowpea and peanut plants, making these plants more tolerant to abiotic stresses and generating increased yield.This study aims: (i) to evaluate the effect of Se on flavonoid profile in roots; (ii) metabolism of N and the antioxidant system and (iii) evaluate the effect of Se on nutrients, carbohydrates profile, water use, gas exchange and grain yield of soybean, peanut and cowpea plants. For physiological (photosynthetic activity, antioxidant metabolism, ureides) and nutritional analyzes, leaves and nodules will be collected during stage R1. The plants will be cultivated until the end of the cycle to determine the components of production and yield and nutritional analysis of the grains. Differential metabolic responses to Se supply can highlight information that will contribute to the resilience of culture in the face of global climate change. (AU)