title: Effects of genetic manipulation of alcohol dehydrogenase levels on the response to stress and the synthesis of secondary metabolites in grapevine leaves.
abstract: The functional role of Adh in regulating susceptibility to abiotic stress and the synthesis of secondary metabolites was investigated in transgenic grapevine plants over- and underexpressing alcohol dehydrogenase (Adh). Plants were transformed with gene constructs containing a sense or antisense orientated grapevine VvAdh2 cDNA under the constitutive cauliflower mosaic virus 35S promoter. Plants transformed with either antisense orientation or the Adh-less construct displayed a low but detectable constitutive ADH activity, whereas plants transformed with the sense-expressed transgene showed a significantly higher (100-fold) ADH activity than the control. Compared with the control, the sense transgene induced an overexpression of VvAdh2 transcripts, whereas a reduced VvAdh2 expression was detected in antisense transformants. Grapevine plants overexpressing Adh displayed a lower sucrose content, a higher degree of polymerization of proanthocyanidins, and a generally increased content of volatile compounds, mainly in carotenoid- and shikimate-derived volatiles. In general, no significant differences between sense/antisense transformants were observed with regard to carotenoid and chlorophyll contents, suggesting a strong metabolic regulation of the synthesis of these compounds.
authors.affiliation: UMR 1083, Sciences Pour l'Oenologie, Centre INRA/Agro-M, 2 Place Viala, F-34060 Montpellier Cedex 01, France. tesniere@ensam.inra.fr
authors.forename: Catherine
authors.initials: C
authors.lastname: Tesniere
authors.forename: Laurent
authors.initials: L
authors.lastname: Torregrosa
authors.forename: Martine
authors.initials: M
authors.lastname: Pradal
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Souquet
authors.forename: Christine
authors.initials: C
authors.lastname: Gilles
authors.forename: Karine
authors.initials: K
authors.lastname: Dos Santos
authors.forename: Philippe
authors.initials: P
authors.lastname: Chatelet
authors.forename: Ziya
authors.initials: Z
authors.lastname: Gunata
mesh_terms: D000426:Alcohol Dehydrogenase / Q000235:genetics / Q000378:metabolism*; D002338:Carotenoids / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism; D003373:Coumaric Acids / Q000378:metabolism; D044948:Flavonols / Q000378:metabolism; D006601:Hexoses / Q000378:metabolism; D045792:Norisoprenoids / Q000378:metabolism; D018515:Plant Leaves / Q000201:enzymology*; D030821:Plants, Genetically Modified; D044945:Proanthocyanidins / Q000378:metabolism; D013729:Terpenes / Q000378:metabolism; D014170:Transformation, Genetic; D027843:Vitis / Q000201:enzymology* / Q000235:genetics
chemical_list: D003373:Coumaric Acids; D044948:Flavonols; D006601:Hexoses; D045792:Norisoprenoids; D044945:Proanthocyanidins; D013729:Terpenes; D002734:Chlorophyll; D002338:Carotenoids; D000426:Alcohol Dehydrogenase