Modification of root and shoot development in monocotyledon and dicotyledon seedlings by 24-epibrassinolide

Abstract

Summary Root development in hydroponically-grown seedlings of wheat, mung bean and maize was impaired by up to 10 µM epiBR in the nutrient medium. In wheat and mung bean, growth of the main root was unaffected, but the number and elongation of lateral roots were reduced at 0.01-0.1 sM epiBR. In maize, root development tended to be inhibited only by the highest concentration of epiBR and effects were not restricted to lateral roots. In wheat and mung bean, epiBR effects were apparent from an early stage of seedling development. Epicotyl elongation in mung bean seedlings was also reduced by 1 sM root-applied epiBR. Both root and shoot biomass in wheat and mung bean were lower following epiBR treatment. An overnight seed soak with epiBR did not impair root development in these species, although reduced epicotyl growth and a slight stimulation of root growth occurred in mung bean.