title: Study of polyamines during grape ripening indicate an important role of polyamine catabolism.
abstract: Grapevine (Vitis species) is the most economically important fruit crop worldwide. Ripening of non-climacteric fruits such as grapes has been the subject of intense research. Despite this interest, little is known on the role played by polyamines in the onset of ripening of non-climacteric fruits. These growth regulators have been involved in plant development and stress responses. Molecular and biochemical studies were developed in three important Portuguese cultivars (Trincadeira, Touriga Nacional and Aragonês) during the year 2008 and in Trincadeira during 2007 in order to gather insights on the role of polyamines in grape ripening. Microarray and real-time qPCR studies revealed up-regulation of a gene coding for arginine decarboxylase (ADC) during grape ripening in all the varieties. This increase was not accompanied by an increase in free and conjugated polyamines that presented a strong decrease. Putrescine and Spermidine levels were higher at earlier stages of development, while Spermine level remained constant. Berries of Trincadeira cultivar presented the highest content in total free and conjugated polyamines at earlier stages of fruit development in particular in the year 2007. The decrease in polyamines content during grape ripening was accompanied by up-regulation of genes coding for diamine oxidase (CuAO) and polyamine oxidase (PAO), together with a significant increase in their enzymatic activity and in the hydrogen peroxide content. These results provide, for the first time, strong evidence of a role of polyamine catabolism in grape ripening possibly through interaction with other growth regulators.
authors.affiliation: Universidade de Lisboa, Faculdade de Ciências de Lisboa, BioFIG, Campo Grande, 1749-016 Lisboa, Portugal.
authors.forename: Patricia
authors.initials: P
authors.lastname: Agudelo-Romero
authors.affiliation: University of Barcelona, Pharmacy Faculty, Av. Diagonal 643, 08028 Barcelona, Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: Bortolloti
authors.affiliation: Universidade de Lisboa, Faculdade de Ciências de Lisboa, BioFIG, Campo Grande, 1749-016 Lisboa, Portugal.
authors.forename: Maria Salomé
authors.initials: MS
authors.lastname: Pais
authors.affiliation: University of Barcelona, Pharmacy Faculty, Av. Diagonal 643, 08028 Barcelona, Spain.
authors.forename: Antonio Fernández
authors.initials: AF
authors.lastname: Tiburcio
authors.affiliation: Universidade de Lisboa, Faculdade de Ciências de Lisboa, BioFIG, Campo Grande, 1749-016 Lisboa, Portugal. Electronic address: amfortes@fc.ul.pt.
authors.forename: Ana Margarida
authors.initials: AM
authors.lastname: Fortes
mesh_terms: D006631:Amine Oxidase (Copper-Containing) / Q000378:metabolism; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000378:metabolism; D011073:Polyamines / Q000378:metabolism*; D011700:Putrescine / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D013096:Spermine / Q000378:metabolism; D027843:Vitis / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism*; D000097667:Polyamine Oxidase
chemical_list: D006631:Amine Oxidase (Copper-Containing); D000587:Oxidoreductases Acting on CH-NH Group Donors; D011073:Polyamines; D011700:Putrescine; D013096:Spermine; D000097667:Polyamine Oxidase
keywords: Copper amine oxidase; Gene expression; Grape ripening; Polyamine catabolism; Polyamine oxidase; Vitis vinifera