IMMUNOLOCALIZATION OF ABSCISIC-ACID BY MONOCLONAL-ANTIBODIES IN LAVANDULA-STOECHAS L LEAVES

A monoclonal antibody was used to localize abscisic acid in Lavandula stoechas L. plants treated with I mu M abscisic acid. ABA localization was performed using EDC as the only fixative, which preserves antigen icity and improves the specificity of monoclonal antibodies. A relatio nship was observed between the effect of abscisic acid on chloroplast ultrastructure and ABA accumulation. Gold particles accumulated on swo llen chloroplasts. Our findings provide cytochemical evidence that the chloroplast is a trapping compartment, and yield valuable information on the relation between chloroplast ultrastructure and ABA accumulati on.