Influence of root-applied epibrassinolide and carbenoxolone on the nodulation and growth of soybean (Glycine max L.) seedlings

24-Epibrassinolide belongs to the brassinosteroid family of plant hormones. and carbenoxolone is a synthetic analogue of glycyrrhizic acid that inhibi ts enzymes important in steroid and prostaglandin action in animals. The ef fect of these compounds on root nodulation, root growth and shoot growth of Glycine max (L.) Merr. cv. Tracy M was examined. Epibrassinolide reduced t otal nodulation, plant wet weight, root length., shoot length, first intern ode length and number of lateral roots. Effects were observed at concentrat ions as low as 0.1 mum. Carbenoxolone reduced lateral root formation, but d id not reduce nodule numbers, root length or weight, nor stem length or wei ght.