Effect of indole-3-butyric acid on the endogenous indole-3-acetic acid and lignin contents in soybean hypocotyl during adventitious root formation

The effect of exogenous indole-3-butyric acid (IBA) on the peroxidase activity during adventitious root formation in hypocotyls of Glycine max was investigated. The hypocotyls of IBA-treated cuttings grew significantly higher numbers of adventitious roots with a decline in lignin levels that corresponded with a decrease in peroxidase activity. Both cationic and anionic peroxidase activities were inhibited during the process of rooting. In addition, the decrease of the cationic peroxidase transcript (pI 7.7) was also observed in IBA-treated hypocotyl during rooting.