Cloning and expression of a hexose transporter gene expressed during the ripening of grape berry.
The ripening of grape (Vitis vinifera L.) is characterized by massive sugar import into the berries. The events triggering this process and the pathways of assimilate transport are still poorly known. A genomic clone Vvht1 (Vitis vinifera hexose transporter1) and the corresponding cDNA encoding a hexose transporter whose expression is induced during berry ripening have been isolated. Vvht1 is expressed mainly in the berries, with a first peak of expression at anthesis, and a second peak about 5 weeks after véraison (a viniculture term for the inception of ripening). Vvht is strictly conserved between two grape cultivars (Pinot Noir and Ugni-Blanc). The organization of the Vvht1 genomic sequence is homologous to that of the Arabidopsis hexose transporter, but differs strongly from that of the Chlorella kessleri hexose transporter genes. The Vvht1 promoter sequence contains several potential regulating cis elements, including ethylene-, abscisic acid-, and sugar-responsive boxes. Comparison of the Vvht1 promoter with the promoter of grape alcohol dehydrogenase, which is expressed at the same time during ripening, also allowed the identification of a 15-bp consensus sequence, which suggests a possible co-regulation of the expression of these genes. The expression of Vvht1 during ripening indicates that sucrose is at least partially cleaved before uptake into the flesh cells.
Fillion
L
L
Laboratoire de Physiologie et Biochimie Végétales, Equipe Scientifique Associée Centre National de la Recherche Scientifique 6161, Unité de Formation et de Recherches Sciences, 40 Avenue du Recteur Pineau, Université de Poitiers, France.
Ageorges
A
A
Picaud
S
S
Coutos-Thévenot
P
P
Lemoine
R
R
Romieu
C
C
Delrot
S
S
D000426:Alcohol Dehydrogenase / Q000235:genetics; D000595:Amino Acid Sequence; D001483:Base Sequence; D001692:Biological Transport; D002241:Carbohydrates / Q000032:analysis; D003001:Cloning, Molecular; D017124:Conserved Sequence; D018076:DNA, Complementary / Q000235:genetics; D005638:Fruit / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D015870:Gene Expression; D017343:Genes, Plant; D015698:Genomic Library; D006601:Hexoses / Q000378:metabolism; D008969:Molecular Sequence Data; D009004:Monosaccharide Transport Proteins / Q000235:genetics*; D010940:Plant Proteins / Q000235:genetics*; D011401:Promoter Regions, Genetic; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019685:Rosales / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D014018:Tissue Distribution
D002241:Carbohydrates; D018076:DNA, Complementary; D006601:Hexoses; D009004:Monosaccharide Transport Proteins; D010940:Plant Proteins; D000426:Alcohol Dehydrogenase