Effects of abscisic acid cyto kinins and light on iso flavonoid phyto alexin accumulation in phaseolus vulgaris cultivar kimburgse vroege
Goossens, J.F.V.; Vendrig, J.C.
Planta (Heidelberg) 154(5): 441-446
ISSN/ISBN: 0032-0935 Accession: 005287377
Cotyledons of P. vulgaris L. contain small amounts of phaseollin and kievitone. Isolating the cotyledons from the plant does not alter phaseollin levels. Kievitone levels, although not affected in light-incubated cotyledons, increased rapidly in dark-incubated cotyledons. Abscisic acid (ABA) at 10-4 M stimulated the accumulation of phaseollin in excised cotyledons in light and darkness, whereas benzylaminopurine (BAP) increased these levels only in the light. The kievitone levels was influenced by ABA and BAP only in dark-incubated cotyledons, i.e., inhibited at 10-4 M. When excised cotyledons were treated with mercuric chloride, phaseollin and kievitone accumulated rapidly in light and darkness. The effect of ABA on these cotyledons was similar to that on non-treated cotyledons. Evidently, the synthesis of the 2 phytoalexins is regulated by separate mechanisms and the phytoalexin composition is dependent on the physiological condition of the cotyledons. ABA and BAP may play a role in the resistance response of the plant.