Effect of light on peroxidase and lignin synthesis in mungbean hypocotyls

Two days of light irradiance reduced the growth of mungbean hypocotyls as well as the levels of endogenous indole-3-acetic acid (IAA). In hypocotyls, both peroxidase and laccase activities were enhanced by light. The lignin content in mungbean hypocotyls was enhanced twofold by light. The inhibition of mungbean hypocotyl growth caused by light might be due to the decline of endogenous IAA, which could be degraded by a cationic peroxidase. The higher levels of lignin were correlated with the increased anionic peroxidase activity in light-treated tissues.