Abstract
5, 6-Difluoroindole-3-acetic acid (5, 6-F2-IAA, 1), a new fluoroindole auxin synthesized via Fischer's indolization, has much a stronger elongation activity on Avena coleoptile segments than indole-3-acetic acid (IAA). Although the optimal concentration of 5, 6-F2-IAA for Avena coleoptile elongation was much higher than that of 5, 6-Cl2-IAA, the extent of elongation was much greater. 5, 6-F2-IAA also induces the formation and promotes the growth of lateral roots of mung bean seedlings. Of the synthetic monofluoro- and difluoro-IAAs, it had the strongest inhibitory activity on hypocotyl growth of Chinese cabbage. It also is moderately rsistant to peroxidase oxidation.
