title: Phenylalanine ammonia-lyase, polyphenol oxidase, and phenol concentration in fruits of Olea europaea L. cv. Picual, Verdial, Arbequina, and Frantoio during ripening.
abstract: The kinetics and protein-expression level of phenylalanine ammonia-lyase (PAL) and polyphenol oxidase (PPO) in fruits of olive trees (Olea europaea) cv. Picual, Verdial, Arbequina, and Frantoio have been studied in relation to the concentration of total phenolic compounds, oleuropein, hydroxytyrosol, and tyrosol during fruit ripening. Frantoio was the variety that showed the highest total phenol concentration, the highest PAL activity, the lowest PPO activity, and the lowest protein levels. In contrast, Verdial was the variety that showed the lowest total phenol concentration, the least PAL activity, the greatest PPO activity, and the highest protein levels. Arbequina and Picual showed intermediate levels. These results suggest the existence of a coordinated response between PAL, PPO, and the concentration of total phenols over ripening in the four varieties. The concentration of total and specific phenols differed between varieties and specifically changed over ripening.
authors.affiliation: Biochemistry and Molecular Biology Section, Department of Experimental Biology, University of Jaen, 23071 Jaen, Spain.
authors.forename: Francisca
authors.initials: F
authors.lastname: Ortega-García
authors.forename: Juan
authors.initials: J
authors.lastname: Peragón
mesh_terms: D001562:Benzimidazoles; D001565:Benzoates; D004156:Catechol Oxidase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D005638:Fruit / Q000737:chemistry / Q000201:enzymology / Q000254:growth & development; D015870:Gene Expression; D006852:Hydrochlorothiazide; D031658:Olea / Q000737:chemistry* / Q000201:enzymology / Q000235:genetics / Q000254:growth & development*; D010636:Phenols / Q000032:analysis*; D010650:Phenylalanine Ammonia-Lyase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: D001562:Benzimidazoles; D001565:Benzoates; C482401:Kinzalkomb; D010636:Phenols; D010940:Plant Proteins; D006852:Hydrochlorothiazide; D004156:Catechol Oxidase; D010650:Phenylalanine Ammonia-Lyase