RESUMO
BACKGROUND: Selenium (Se) is a nutrient for animals and humans, and is considered beneficial to higher plants. Selenium concentrations are low in most soils, which can result in a lack of Se in plants, and consequently in human diets. Phytic acid (PA) is the main storage form of phosphorus in seeds, and it is able to form insoluble complexes with essential minerals in the monogastric gut. This study aimed to establish optimal levels of Se application to cowpea, with the aim of increasing Se concentrations. The efficiency of agronomic biofortification was evaluated by the application of seven levels of Se (0, 2.5, 5, 10, 20, 40, and 60 g ha-1 ) from two sources (selenate and selenite) to the soil under field conditions in 2016 and 2017. RESULTS: Application of Se as selenate led to greater plant Se concentrations than application as selenite in both leaves and grains. Assuming human cowpea consumption of 54.2 g day-1 , Se application of 20 g ha-1 in 2016 or 10 g ha-1 in 2017 as selenate would have provided a suitable daily intake of Se (between 20 and 55 µg day-1 ) for humans. Phytic acid showed no direct response to Se application. CONCLUSION: Selenate provides greater phytoavailability than selenite. The application of 10 g Se ha-1 of selenate to cowpea plants could provide sufficient seed Se to increase daily human intake by 13-14 µg d-1 . © 2019 Society of Chemical Industry.
Assuntos
Biofortificação/métodos , Ácido Fítico/análise , Ácido Selênico/análise , Ácido Selenioso/análise , Selênio/análise , Vigna/química , Fertilizantes/análise , Ácido Fítico/metabolismo , Folhas de Planta/química , Folhas de Planta/metabolismo , Sementes/química , Sementes/metabolismo , Vigna/metabolismoRESUMO
Analysis of DNA polymorphic sites is an important tool for the detection of gene flow in human evolutionary studies and to study the genetic background for gene mutations. The beta-globin locus contains several single-base restriction fragment length polymorphism (RFLP) sites throughout chromosome 11. In addition to these polymorphic sequence repeats, others are being studied in order to expand our knowledge concerning the role between haplotype-genotype and phenotype associations. Far downstream of the expressed beta-globin genes, there is a hypersensitive site (HS) whose function remains obscure. We sequenced this region in 27 thalassemia patients and found a new pattern in the micro-satellite-like AT-rich region of this site: a new TAA insertion in addition to the one previously described in sickle cell patients with a concomitant polymorphism (G-->A). This new variation was found to be linked to the IVS-I-6 (T-->C) mutation. This polymorphism may be useful for studies concerning genotype and phenotype associations.