Molecular cloning and expression analysis of a gene for sucrose transporter from pear (Pyrus bretschneideri Rehd.) fruit.
Here we report the cloning of a sucrose transporter cDNA from pear (Pyrus bretschneideri Rehd. cv 'Yali') fruit and an analysis of the expression of the gene. A cDNA clone, designated PbSUT1 was identified as a sucrose transporter cDNA from its sequence homology at the amino acid level to sucrose transporters that have been cloned from other higher plant species. PbSUT1 potentially encoded a protein of 499 amino acid residues with a predicted molecular mass of 53.4 kDa and an isoelectric point (pI) of 9.21. Phylogenetic analysis revealed that the PbSUT1 belonged to type III SUTs and was more closely related to the MdSUT1 from apple fruit. Some major facilitator superfamily (MFS)-specific sequence motifs were found in the predicted PbSUT1 peptides, and an MFS_1 domain was located at the amino acid positions of 29-447 of the sequence. A study of gene expression along fruit development showed that PbSUT1 transcripts are present at all stages but significantly increase before fruit enlargement and during the ripening process with increasing sucrose levels. In contrast, the expression levels don't change much during the period of rapid fruit growth. This work shows that sucrose transporter may play a role in the accumulation of sugars during maturation and in maintaining the internal cellular distribution.
Centre of Pear Engineering & Technology Research, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, PR China; Department of Horticulture, College of Agriculture, Shihezi University, Shihezi 832003, PR China.
Huping
H
Zhang
Shujun
S
Zhang
Gaihua
G
Qin
Lifen
L
Wang
Tao
T
Wu
Kaijie
K
Qi
Shaoling
S
Zhang
D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary; D005638:Fruit / Q000254:growth & development / Q000378:metabolism; D015870:Gene Expression; D017343:Genes, Plant; D007526:Isoelectric Point; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009004:Monosaccharide Transport Proteins / Q000235:genetics* / Q000378:metabolism; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D031989:Pyrus / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D017385:Sequence Homology; D013395:Sucrose / Q000378:metabolism*
D018076:DNA, Complementary; D009004:Monosaccharide Transport Proteins; D010940:Plant Proteins; D013395:Sucrose
Cloning; Expression; Pear fruit; Sucrose transporter