Elevated Ultraviolet-B Radiation Reduces Concentrations of Isoflavones and Phenolic Compounds in Soybean Seeds

Abstract

The gradual disruption of the ozone layer in the stratosphere has resulted in increased exposure of plants to ultraviolet-B (UV-B, 280–315 nm) radiation. UV-B radiation is known to affect crop growth and quality negatively. A study was conducted to determine the impact of elevated UV-B radiation levels on the isoflavones and phenolic compound concentrations of seven soybean varieties. UV-B radiation significantly reduced the concentration of most isoflavones and phenolic compounds in soybean seeds. Exposure to elevated UV-B levels overall resulted in 35 % reduction in total isoflavones and 31 % in phenolic compounds concentrations. The effect on individual isoflavones and phenolic compounds depended on the compound and variety, but UV-B overwhelmingly reduced concentrations. This study suggests that increased UV-B radiation negatively impacted soybean quality by reducing the concentration of compounds that have health-beneficial properties.