Differential modulation of root formation in wheat embryogenic callus culture by indoleacetic acid-degrading compounds

Root overproduction in embryogenic calli of wheat cv. ‘ChineseSpring’ was controlled by the addition of IAA-degradingcompounds (citric acid, MnSO4 or EDTA) to the culture media.In the presence of 20 gl^–1 sucrose, the number of rootson calli decreased significantly when media for either callusmaintenance or plant regeneration were amended with citric acid.EDTA was less effective in reducing the number of roots thancitric acid. An increase in the amount of a 31kDa (P1) polypeptideunder conditions which favoured a reduction in root formationwas observed. Key words: Wheat, Triticum aestivum, IAA-degrading compounds, indoleacetic acid, root number.