RESUMO
Climate change poses a serious threat to agricultural production. Water deficit in agricultural soils is one of the consequences of climate change that has a negative impact on crop growth and yield. Selenium (Se) is known to be involved in plant defense against biotic and abiotic stress through metabolic, structural, and physiological activity in higher plants. The aim of this study was to investigate the physiological response of Se-biofortified soybean (Glycine max (L.) Merrill) seedlings under osmotic stress. For this research, we used biofortified soybean grain obtained after foliar Se biofortification in 2020. The experiment was conducted in a growth chamber with two cultivars (Lucija and Sonja) grown on filter paper in three replicates. The experiment was carried out with two watering treatments: distilled water (PEG-0) and 2.5% polyethylene glycol 6000 (PEG-2.5) on Se-biofortified seeds (Se) and nonbiofortified seeds (wSe). Contents of lipid peroxidation product (LP), free proline (PRO), total phenolic content (TP), ferric reducing antioxidant power (FRAP), and ascorbic acid (AA) were analyzed in 7-days-old seedlings. Significant differences were detected in the Se content of soybean grains between the two cultivars. A milder reaction to PEG-2.5 was observed in cultivar Lucija in both Se and wSe treatments, which might represent the mitigating effects of Se on osmotic stress in this cultivar. Contrarily, in cultivar Sonja, Se adversely affected all analyzed traits in the PEG-2.5 treatment. Ultimately, Se is a pro-oxidant in Sonja, whereas it represents an anti-oxidant in Lucija. In conclusion, different soybean cultivars show contrasting physiological reactions to both osmotic stress and Se. However, the activation of antioxidant pathways in Sonja can also be interpreted as added value in soybean seedlings as a functional food.
RESUMO
BACKGROUND: Extensive and growing use of different chemical pesticides that affect both the environment and human health raises a need for new and more suitable methods to deal with plant pathogens. Nanotechnology has enabled the use of materials at the nanoscale with exceptional functionality in different economic domains including agricultural production. This study aimed to evaluate antifungal potential of selenium nanoparticles (SeNPs) and silver nanoparticles (AgNPs) stabilized with different surface coatings and characterized by different surface charge on plant pathogenic fungi Macrophomina phaseolina, Sclerotinia sclerotiorum and Diaporthe longicolla. RESULTS: AgNPs were coated with three different stabilizing agents: mono citrate (MC-AgNPs), cetyltrimethyl ammonium bromide (CTAB-AgNPs) and polyvinylpyrrolidon (PVP-AgNPs). SeNPs were coated with poly-l-lysine (PLL-SeNPs), polyacrylic acid (PAA-SeNPs), and polyvinylpyrrolidon (PVP-SeNPs). Seven different concentrations (0.1, 0.5, 1, 5, 10, 50 and 100 mg L-1 ) of nanoparticles were applied. All AgNPs and SeNPs significantly inhibited the growth of the tested fungi. Among the tested NPs, PVP-AgNPs showed the best inhibitory effect on the tested plant pathogenic fungi, especially against S. sclerotiorum. The similar inhibition of the sclerotia formation was observed for S. sclerotiorum treated with PLL-SeNPs. CONCLUSION: Obtained results provides new insights on fungicide effect of AgNPs and SeNPs stabilized with different coating agents on different plant pathogens. Further work should focus on detailed risk/benefit ratio assessment of using SeNPs or AgNPs in agriculture taking into account whole agroecosystem. © 2020 Society of Chemical Industry.