Increased soybean tolerance to water deficiency through biostimulant based on fulvic acids and Ascophyllum nodosum (L.) seaweed extract.

To meet the growing demand for soybean it is necessary to increase crop yield, even in low water availability conditions. To circumvent the negative effects of water deficit, application of biostimulants with anti-stress effect has been adopted, including products based on fulvic acids and Ascophyllum nodosum (L.) seaweed extracts. In this study, we determined which formulation and dosage of a biostimulant is more efficient in promoting the recovery of soybean plants after stress due to water deficit. The experiment was conducted in a greenhouse, in a double-factorial randomized block design with two additional factors, four repetitions and eleven treatments consisting of three biostimulant formulations (F1, F2 and F3), and three dosages (0.25; 0.50 and 1.0 kg ha-1); a control with water deficit and a control without water deficit. Soybean plants were kept at 50% of the pot's water capacity for three days, then rehydrated and submitted to the application of treatments with biostimulant. After two days of recovery, growth, physiological, biochemical and yield parameters were evaluated. All plants that received the application of the biostimulant produced more than the water-stressed control plants. The biostimulant provided higher photosynthetic rates, more efficient mechanisms for dissipating excess energy and higher activities of antioxidant enzymes. Plants treated with biostimulant were more efficient in the recovery of the metabolic activities after rewatering, resulting in increased soybean tolerance to water deficit and reduced yield losses. The best result obtained was through the application of formulation 2 of the biostimulant at a dosage of 0.25 kg ha-1.

Contribution of nitrogen derived from mineral supplementation for soybean seedlings / Contribuição do nitrogênio derivado da suplementação mineral em sementes para plântulas de soja

ABSTRACT Seeds can absorb N from mineral supplementation, thus stimulating seedling development in soybeans (Glycine max (L.) Merrill). This study aimed to evaluate the contribution to soybean seedlings of N derived from mineral supplementation in seeds with different nutritional contents. Seeds of the cultivar BMX Potência RR received mineral supplementation enriched with 2.5% excess 15N. The treatments were performed in seeds in two lots, one with high and one with low nutritional content. At 2, 6 and 10 days after sowing on paper towels, the seedlings were collected and separated into cotyledons, roots and shoots. Dry matter production, root length and root volume were assessed. Total N and 15N values were analyzed in the seedling organ tissues. The seeds from the lot with lower nutritional content absorbed more N from the mineral supplement, which was accumulated in the cotyledons and redistributed to the root systems and cotyledons. At 10 days after sowing, most of the N in the organs of soybean seedlings was derived from the seed reserves, regardless of nutritional content. Thus, application of N through mineral supplementation is of low importance for the development and nutrition of seedlings.

RESUMO Sementes podem absorver N de suplementos minerais, estimulando o desenvolvimento de plântulas. O estudo objetivou avaliar a contribuição de N derivado da suplementação mineral em sementes com diferentes teores nutricionais, para plântulas de soja. Sementes de dois lotes da cultivar BMX Potência RR, contrastantes quanto ao teor nutricional, foram submetidas a aplicação de suplemento mineral enriquecido com 2,5% átomos de 15N em excesso. Aos 2, 6 e 10 dias após a semeadura em papel toalha, plântulas foram coletadas, separadas em cotilédones, sistema radicular e parte aérea. A produção de matéria seca, o comprimento e volume do sistema radicular foram avaliados. No tecido dos órgãos das plântulas foram analisados os totais de N e 15N. As sementes derivadas do lote com menor teor nutricional absorveram mais N do suplemento mineral, que foi acumulado nos cotilédones e redistribuído para o sistema radicular e parte aérea. A maior parte do N na soja ao longo de 10 dias após a semeadura é derivada das reservas da semente independentemente do teor nutricional inicial. A aplicação de N via suplementação mineral é de pouca importância para o crescimento e desenvolvimento de plântulas.

Ameliorative effects of Monascus pilosus-fermented black soybean (Glycine max L. Merrill) on high-fat diet-induced obesity.

The purpose of this study was to examine the antiobesity effects of Monascus pilosus-fermented black soybean (F-BS) in C57BL/6 mice with high-fat diet (HFD)-induced obesity. F-BS (oral, 0.5 and 1.0 g/kg per body weight, twice per day) ameliorated obesity by reducing body and liver weight increases, and regulating blood glucose and cholesterol levels in C57BL/6 mice fed a control or HFD with oral administration of F-BS for 12 weeks. F-BS suppressed the growth of epididymal, retroperitoneal, and perirenal fat pads by preventing increases in the adipocyte size. Moreover, the levels of blood glucose, total cholesterol, and leptin were significantly lowered by F-BS administration in a dose-dependent manner. These results indicated that F-BS is a beneficial food supplement for preventing obesity, controlling blood glucose, and lowering cholesterol. Future research strategies should address the mechanisms that selectively regulate obesity, including hyperglycemia and hypercholesterolemia.