title: Characterization of a bZIP gene highly expressed during ripening of the peach fruit.
abstract: A ripening specific bZIP gene of peach was studied by ectopically expressing it in tomato. Two lines, with either a mild or a strong phenotype, respectively, were analyzed in detail. Transgenic fruit morphology was normal, yet the time spent to proceed through the various ripening stages was longer compared to wild type. In agreement with this finding the transgenic berries produced less ethylene, and also had a modified expression of some ripening-related genes that was particularly evident in berries with a strong phenotype. In particular, in the latter fruits polygalacturonase and lipoxygenase genes, but also genes coding for transcription factors (TFs) important for tomato ripening (i.e. TAGL1, CNR, APETALA2a, NOR) did not show the expected decreased expression in the red berries. As regards the RIN gene, its expression continued to increase in both mild and strong lines, and this is in agreement with the dilated ripening times. Interestingly, a metabolomic analysis of berries at various stages of ripening showed that the longer time spent by the transgenic berries to proceed from a stage to another was not due to a slackened metabolism. In fact, the differences in amount of stage-specific marker metabolites indicated that the transgenic berries had a very active metabolism. Therefore, the dilated ripening and the enhanced metabolism of the berries over-expressing the bZIP gene suggest that such gene might regulate ripening by acting as a pacemaker for some of the ripening metabolic pathways.
authors.affiliation: Department of Biology, University of Padua, Via G. Colombo 3, 35131 Padua, Italy. alessandro.lovisetto@unipd.it
authors.forename: Alessandro
authors.initials: A
authors.lastname: Lovisetto
authors.forename: Flavia
authors.initials: F
authors.lastname: Guzzo
authors.forename: Alice
authors.initials: A
authors.lastname: Tadiello
authors.forename: Enrico
authors.initials: E
authors.lastname: Confortin
authors.forename: Anna
authors.initials: A
authors.lastname: Pavanello
authors.forename: Alessandro
authors.initials: A
authors.lastname: Botton
authors.forename: Giorgio
authors.initials: G
authors.lastname: Casadoro
mesh_terms: D050976:Basic-Leucine Zipper Transcription Factors / Q000235:genetics* / Q000378:metabolism; D005030:Ethylenes / Q000378:metabolism; D005638:Fruit / Q000254:growth & development / Q000378:metabolism*; D015870:Gene Expression; D017343:Genes, Plant; D008084:Lipoxygenase / Q000235:genetics / Q000378:metabolism; D018551:Solanum lycopersicum / Q000145:classification / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D055442:Metabolome; D063245:Plant Development / Q000235:genetics*; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified; D011096:Polygalacturonase / Q000235:genetics / Q000378:metabolism; D027861:Prunus / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D013045:Species Specificity; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D050976:Basic-Leucine Zipper Transcription Factors; D005030:Ethylenes; D010940:Plant Proteins; D014157:Transcription Factors; C036216:ethylene; D008084:Lipoxygenase; D011096:Polygalacturonase
keywords: Fruit ripening; Gene expression; Metabolomic analysis; Prunus persica; Solanum lycopersicon; bZIP gene