title: Expression profiling of ascorbic acid-related genes during tomato fruit development and ripening and in response to stress conditions.
abstract: L-ascorbate (the reduced form of vitamin C) participates in diverse biological processes including pathogen defence mechanisms, and the modulation of plant growth and morphology, and also acts as an enzyme cofactor and redox status indicator. One of its chief biological functions is as an antioxidant. L-ascorbate intake has been implicated in the prevention/alleviation of varied human ailments and diseases including cancer. To study the regulation of accumulation of this important nutraceutical in fruit, the expression of 24 tomato (Solanum lycopersicon) genes involved in the biosynthesis, oxidation, and recycling of L-ascorbate during the development and ripening of fruit have been characterized. Taken together with L-ascorbate abundance data, the results show distinct changes in the expression profiles for these genes, implicating them in nodal regulatory roles during the process of L-ascorbate accumulation in tomato fruit. The expression of these genes was further studied in the context of abiotic and post-harvest stress, including the effects of heat, cold, wounding, oxygen supply, and ethylene. Important aspects of the hypoxic and post-anoxic response in tomato fruit are discussed. The data suggest that L-galactose-1-phosphate phosphatase could play an important role in regulating ascorbic acid accumulation during tomato fruit development and ripening.
authors.affiliation: Group of Biotechnology of Pharmaceutical Plants, Division of Pharmacognosy-Pharmacology, Department of Pharmaceutical Sciences, Aristotle University of Thessaloniki, 541 24 Thessaloniki, Greece.
authors.forename: Eugenia
authors.initials: E
authors.lastname: Ioannidi
authors.forename: Mary S
authors.initials: MS
authors.lastname: Kalamaki
authors.forename: Cawas
authors.initials: C
authors.lastname: Engineer
authors.forename: Irene
authors.initials: I
authors.lastname: Pateraki
authors.forename: Dimitris
authors.initials: D
authors.lastname: Alexandrou
authors.forename: Ifigeneia
authors.initials: I
authors.lastname: Mellidou
authors.forename: James
authors.initials: J
authors.lastname: Giovannonni
authors.forename: Angelos K
authors.initials: AK
authors.lastname: Kanellis
mesh_terms: D000693:Anaerobiosis / Q000187:drug effects; D001205:Ascorbic Acid / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D005030:Ethylenes / Q000494:pharmacology; D005638:Fruit / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development*; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant; D018551:Solanum lycopersicum / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development*; D010084:Oxidation-Reduction / Q000187:drug effects; D011401:Promoter Regions, Genetic / Q000235:genetics; D013312:Stress, Physiological / Q000187:drug effects / Q000235:genetics*
chemical_list: D005030:Ethylenes; C036216:ethylene; D001205:Ascorbic Acid