Selenium absorption kinetics and localization in cowpea genotypes using XRF technique associated with physiological and biochemical responses

Author(s)

Maria Gabriela Dantas Bereta Lanza Lanza

• Document type: Master's Dissertation
• Press: Jaboticabal. 2022-04-11.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Ciências Agrárias e Veterinárias. Jaboticabal
• Defense date: 2022-02-10
• Advisor: André Rodrigues dos Reis; Hudson Wallace Pereira de Carvalho

Abstract

Selenium (Se) is an essential element for humans and animals and is beneficial to plants. Soils are poor in Se, making the population's diet deficient. Agronomic biofortification is a strategy to increase Se levels in plants. In this work, we investigated the efficiency of mineral supplementation dependent on genotypic factors and the adequate source of Se. Three experiments were conducted, two preliminary experiments and one critical experiment. In experiment 1, concentrations of Na2SeO4 (0, 20, 40, 80, and 120 µM) in cowpea plants (Vigna unguiculata [L.] Walp cv. BRS Rouxinol), were evaluated to determine the best concentration-response for the in vivo evaluation of plants using the X-ray fluorescence (XRF) technique. In experiment 2, the best concentration-response (40 µM) was used to evaluate the Se absorption efficiency of 20 commercial cowpea genotypes, using Se concentration in shoots and roots by the X-ray fluorescence technique bench energy dispersive (EDXRF) to determine genotypes with contrasting absorption capacity. In experiment 3, the genotype with the highest (BRS Xiquexique) and lowest (BRS Urubuquara) Se absorption capacity was selected. Moreover, evaluating the physiological responses of the application of two Se sources (Na2SeO4 and Na2SeO3), to identify the most efficient source for the absorption and translocation of Se to the shoot of the plants, aiming at the generation of plants with greater nutritional value. Our results demonstrate the presence of genotypic variation in the cowpea crop and relate the ability of efficient plants to translocate Se from roots to shoots with the high efficiency of photosynthetic metabolism. Furthermore, the Na2SeO4 source proved to be an excellent alternative to ensure the root-shoot Se translocation in cowpea plants. (AU)

• FAPESP's process: 19/19114-2 - Analysis of selenium absorption kinetics and localization in cowpea genotypes using the u-XRF technique associated with physiological and biochemical responses
• Grantee: Maria Gabriela Dantas Bereta Lanza
• Support Opportunities: Scholarships in Brazil - Master