Biofortificação agronômica com selênio e alterações metabólicas em trigo

Abstract

Selenium is an element essential to humans and animals. The deficiency of this mineral occurs in more than one billion people. Biofortification is an efficient strategy for countering this deficiency. In addition, selenium is, possibly, beneficial to plants. Thus, the present study aims at seeking information and alternatives for the biofortification of wheat with Se in the field, in addition to proving its beneficial effect to plants, and the reasons leading to the higher production and accumulation of biomass. Wheat plants were treated with different concentrations of Se (12, 21, 38, 68 and 120 g Se ha -1 ), using selenate as source. We conducted two studies. In the first, we provided Se via root. In the second, we provided Se via leaves, divided into two application of equal concentrations. In both studies, biochemical and physiological analyses were conducted. It was observed that, regardless of the means of provision – via soil or leaf -, there was accumulation of Se in grains and shoot, increment in the contents of carbohydrates, and in the activities of catalase and ascorbate peroxidase. In addition, all treatments via soil promoted increments in the SPAD readings. Se caused beneficial effects to wheat plants, resulting in a higher accumulation of shoot biomass and, in plants submitted to fertilization via leaf, with 21 and 120 g ha -1 of Se, occurred higher production. The treatment with 21 g ha -1 of Se via leaf promoted the increment of liquid photosynthesis and of the content of total nitrogen. Both means of Se provision are efficient for the biofortification of wheat in the field.