JASMONIC ACID AND ABSCISIC-ACID IN SHOOTS, COLEOPTILES, AND ROOTS OF WHEAT SEEDLINGS

The endogenous levels of abscisic acid (ABA) and jasmonic acid (JA) we re analyzed in wheat seedlings grown in water, a system which in the p ast has been used to test the effects of these plant growth inhibitors . The levels in different plant parts and in the medium were measured by gas chromatography-mass spectrometry-selected ion monitoring, using [H-2(3)]ABA and [H-2(6)]JA as internal standards. In every plant part , JA levels were about 2 orders of magnitude greater than those of ABA . The exudation of JA from roots per seedling was about 14,000-fold gr eater than that of ABA, although the roots contained only about 170 ti mes more JA than ABA. It is suggested that JA is a possible allelopath ic compound.