Ultraviolet-B radiation modifies the quantitative and qualitative profile of flavonoids and amino acids in grape berries.
Grapevine cv. Tempranillo fruit-bearing cuttings were exposed to supplemental ultraviolet-B (UV-B) radiation under controlled conditions, in order to study its effect on grape traits, ripening, amino acids and flavonoid profile. The plants were exposed to two doses of UV-B biologically effective (5.98 and 9.66kJm(-2)d(-1)), applied either from fruit set to ripeness or from the onset of veraison to ripeness. A 0kJm(-2)d(-1) treatment was included as a control. UV-B did not significantly modify grape berry size, but increased the relative mass of berry skin. Time to reach ripeness was not affected by UV-B, which may explain the lack of changes in technological maturity. The concentration of must extractable anthocyanins, colour density and skin flavonols were enhanced by UV-B, especially in plants exposed from fruit set. The quantitative and qualitative profile of grape skin flavonols were modified by UV-B radiation. Monosubstituted flavonols relative abundance increased proportionally to the accumulated UV-B doses. Furthermore, trisubstituted forms, which where predominant in non-exposed berries, were less abundant as UV-B exposure increased. Although total free amino acid content remained unaffected by the treatments, the increased levels of gamma-aminobutyric acid (GABA), as well as the decrease in threonine, isoleucine, methionine, serine and glycine, revealed a potential influence of UV-B on the GABA-mediated signalling and amino acid metabolism. UV-B had an overall positive impact on grape berry composition.
INRA, Institut des Sciences de la Vigne et du Vin, UMR1287 EGFV, 210 Chemin de Leysotte, 33883 Villenave d'Ornon, France; University of Bordeaux, Institut des Sciences de la Vigne et du Vin, UMR1287 EGFV, 210 Chemin de Leysotte, 33883 Villenave d'Ornon, France; Universidad de Navarra, Grupo de Fisiología del Estrés en Plantas (Dpto. de Biología Ambiental), Unidad Asociada al CSIC, EEAD, Zaragoza e ICVV, Logroño, Irunlarrea, 1, 31008 Pamplona, Spain.
J
J
Martínez-Lüscher
Universidad de Navarra, Grupo de Fisiología del Estrés en Plantas (Dpto. de Biología Ambiental), Unidad Asociada al CSIC, EEAD, Zaragoza e ICVV, Logroño, Irunlarrea, 1, 31008 Pamplona, Spain.
N
N
Torres
INRA, Institut des Sciences de la Vigne et du Vin, UMR1287 EGFV, 210 Chemin de Leysotte, 33883 Villenave d'Ornon, France.
G
G
Hilbert
GESVAB (EA 3675), ISVV, University of Bordeaux, 33882 Villenave d'Ornon, France.
T
T
Richard
Universidad de Navarra, Grupo de Fisiología del Estrés en Plantas (Dpto. de Biología Ambiental), Unidad Asociada al CSIC, EEAD, Zaragoza e ICVV, Logroño, Irunlarrea, 1, 31008 Pamplona, Spain.
M
M
Sánchez-Díaz
INRA, Institut des Sciences de la Vigne et du Vin, UMR1287 EGFV, 210 Chemin de Leysotte, 33883 Villenave d'Ornon, France; University of Bordeaux, Institut des Sciences de la Vigne et du Vin, UMR1287 EGFV, 210 Chemin de Leysotte, 33883 Villenave d'Ornon, France.
S
S
Delrot
Universidad de Navarra, Grupo de Fisiología del Estrés en Plantas (Dpto. de Biología Ambiental), Unidad Asociada al CSIC, EEAD, Zaragoza e ICVV, Logroño, Irunlarrea, 1, 31008 Pamplona, Spain.
J
J
Aguirreolea
Universidad de Navarra, Grupo de Fisiología del Estrés en Plantas (Dpto. de Biología Ambiental), Unidad Asociada al CSIC, EEAD, Zaragoza e ICVV, Logroño, Irunlarrea, 1, 31008 Pamplona, Spain.
I
I
Pascual
INRA, Institut des Sciences de la Vigne et du Vin, UMR1287 EGFV, 210 Chemin de Leysotte, 33883 Villenave d'Ornon, France; University of Bordeaux, Institut des Sciences de la Vigne et du Vin, UMR1287 EGFV, 210 Chemin de Leysotte, 33883 Villenave d'Ornon, France. Electronic address: eric.gomes@bordeaux.inra.fr.
E
E
Gomès
D000596:Amino Acids / Q000737:chemistry*; D005419:Flavonoids / Q000737:chemistry*; D005638:Fruit / Q000737:chemistry*; D014466:Ultraviolet Rays; D027843:Vitis / Q000737:chemistry*
D000596:Amino Acids; D005419:Flavonoids
Abiotic stress; Flavonoids; Grapevine; Metabolites; Ultraviolet radiation