REGULACIóN ESPACIO-TEMPORAL DE FENILALANLNA AMONIO LIASA EN CLAVEL (Dianthus caryophyllus L.) DURANTE SU INTERACCIóN CON EL PATóGENO Fusarium oxysporum f. sp. dianthi

the spatio-temporal regulation of enzymatic activity and that of transcriptional levels of phenylalanine ammonia lyase enzyme in cuttings of carnation infected with the pathogen responsible of vascular wilting were studied. carnation cuttings of two varieties which differ in disease tolerance-kiss (tolerant) and uconn (sus-ceptible)-were inoculated with fusarium oxysporum f sp. dianthi and samplings were taken from root and stem at different times after inoculate them, to evaluate the parameters of interest. during infection, the tolerant variety showed an induction of pal at 48 hours post-inoculation in roots, showing in this organ that the phenylpropanid pathway is stimulated. this pathway is responsible for producing phenolic metabolites that participate in phenomena associated with plant resistance. having in account that during the evaluation of transcription levels in root, measured with semiquantitative technique rt-pcr, the levels of pal mrna were not increased, the participation of post-transcriptional regulation mechanisms for this active enzyme is evident. taking in consideration that stem not presented differential induction in the enzymatic activity nor in levels of mrna, we evidenced that regulation of responses of plant defense in this model is determined by the organ of the plant involved in the infection process.