Effects of Foliar Application of Nano-Se On Photosynthetic Characteristics and Se Accumulation in Paeonia Ostii
Abstract Background Selenium is an essential micronutrient in human metabolism. However, the Se level in foods is far below the standards due to the fact that it is deficient in two thirds of arable soils. Therefore, consuming Se-enriched plant products which convert inorganic Se into organic Se might be a safe and effective way to supplement Se for the human body. Paeonia ostii is a unique medicinal and edible plant in China, and also a new special woody oil crop. It serves as a perfect mediator for Se biofortification. In this report the effects of nano-Se foliar application on photosynthetic parameters, physiological characteristics and Se-enrichment effect in various plant organs of P. ostii cultivar Feng Dan were investigated in randomized complete block design experiments with different doses of spray in Se-deficient soils.Results By contrast to the control, nano-Se sprays enhanced net photosynthetic rate, transpiration rate, stomatal conductance, intercellular CO2 concentration, and chlorophyll content of Feng Dan. The content of soluble sugar, soluble protein, proline and activities of superoxide dismutase and peroxidase were increased while malondialdehyde content was significantly reduced. The stimulatory effect at concentrations of 6.00 and 8.25 g·hm-2 was the best in this study. nano-Se application significantly increased the Se content in all organs of Fengdan except the root compared to the control, and Se contents in various organs were increased paralleled with the increase of concentrations applied, and ordered as follows under suitable concentration, Testa > leaf > kernel > stem > root.ConclusionsThe above results show that nano-Se sprays at concentrations of 6.00-8.25 g·hm-2 stimulated the growth of Feng Dan and achieved the best Se-enrichment effect in this study. It also proved that the Se biofortification effect depends on its dosage applied and types of plant organs. These results provide guidance on Se enrichment of horticultural crops.