Selenium and sulfur interaction on amino acids and flavonoids metabolism and relations with nodulation of legume plants

Abstract

Selenium (Se) is essential element to humans and animals, and considered benefit to higher plants at low concentration. Selenium application as selenate source share similarities with sulfur (S) in transport and assimilation by plants. Thus, Se can affect S uptake and assimilation and vice-versa, which could lead to alterations in metabolisms pathways related to S and Se, such as flavonoids and amino acids biosynthesis. This study aims to evaluate Se and S combination on flavonoid and amino acids in legume plants. Sulfur is present in cysteine and methionine and also regulates flavonoid metabolism. Flavonoids are small molecules driving the chemotaxis and communication between roots and Rhizobia bacteria regulating the nodulation of legume plants. A greenhouse experiment will be carried out to evaluate the effect of Se x S combination on amino acids and flavonoids profile and its relations with nodulation of soybean and cowpea plants. The experimental design will be a fully randomized composed by four treatments: control, Se (10 ¼M), S (5 mM) and Se (10 ¼M) + S (5 mM), and four replications. Legume plants will be cultivated in nutrient to collect roots and nodules for amino acids profile; flavonoids (daidzein, genistein, myricetin, naringenin, kaempferol, and quercetin), gene expression of Sultr1;1, Sultr2;1, ATP sulfurylase (APS), ATP sulfurylase reductase (APR), chalcone synthase (CHS), chalcone reductase (CHR) and isoflavone synthase (IFS). Understanding the nodulation is an important information to improve the biological nitrogen fixation of legume plants to increase the yield and nutritional quality of edible crops. (AU)