Some Growth Promotive Effects of Abscisic Acid

Abstract

Abscisic acid promoted increase in frond number and fresh weight in Lemna polyrhiza when applied at low concentrations although higher concentrations inhibited both parameters. Elongation of coleoptile segments of oats and wheat was also promoted by low ABA concentrations when the coleoptile tip was not excised, although when the tip was removed no significant promotion was detected. Elongation of mesocotyl segments of oats and maize was promoted by ABA and in these cases the maximum promotion occurred at higher concentrations with maximum elongation of maize mesocotyl segments occurring at the highest concentration tested. The dose-response relationship for ABA appears to be similar to that reported for IAA in some tissues.