UDP-galactose transporter gene hUGT1 expression in tobacco plants leads to hyper-galactosylated cell wall components.
We reported previously that tobacco plants transformed with the human UDP-galactose transporter 1 gene (hUGT1-transgenic plants) displayed morphological, architectural, and physiological alterations, such as enhanced growth, increased accumulation of chlorophyll and lignin, and a gibberellin-responsive phenotype. In the present study, we demonstrated that hUGT1 expression altered the monosaccharide composition of cell wall matrix polysaccharides, such as pectic and hemicellulosic polysaccharides, which are biosynthesized in the Golgi lumen. An analysis of the monosaccharide composition of the cell wall matrix polysaccharides revealed that the ratio of galactose to total monosaccharides was significantly elevated in the hemicellulose II and pectin fractions of hUGT1-transgenic plants compared with that of control plants. A hyper-galactosylated xyloglucan structure was detected in hemicellulose II using oligosaccharide mass profiling. These results indicated that, because of the enhanced UDP-galactose transport from the cytosol to the Golgi apparatus by hUGT1, galactose incorporation in the cell wall matrix polysaccharides increased. This increased galactose incorporation may have contributed to increased galactose tolerance in hUGT1-transgenic plants.
Center for Gene Science, Hiroshima University, 1-4-2 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8527, Japan.
Tayebeh
T
Abedi
Center for Gene Science, Hiroshima University, 1-4-2 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8527, Japan.
Mohamed Farouk Mohamed
MF
Khalil
Center for Gene Science, Hiroshima University, 1-4-2 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8527, Japan.
Toshihiko
T
Asai
Center for Gene Science, Hiroshima University, 1-4-2 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8527, Japan.
Nami
N
Ishihara
Center for Gene Science, Hiroshima University, 1-4-2 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8527, Japan.
Kenji
K
Kitamura
Department of Environmental Security Systems, Faculty of Risk and Crisis Management, Chiba Institute of Science, 3 Shiomi-cho, Choshi, Chiba 288-0025, Japan.
Nobuhiro
N
Ishida
Center for Gene Science, Hiroshima University, 1-4-2 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8527, Japan. Electronic address: ntana@hiroshima-u.ac.jp.
Nobukazu
N
Tanaka
D001692:Biological Transport; D002473:Cell Wall / Q000737:chemistry* / Q000378:metabolism*; D003600:Cytosol / Q000378:metabolism; D005690:Galactose / Q000378:metabolism*; D015870:Gene Expression; D005936:Glucans / Q000378:metabolism; D006056:Golgi Apparatus / Q000378:metabolism; D006801:Humans; D009004:Monosaccharide Transport Proteins / Q000235:genetics* / Q000378:metabolism*; D010368:Pectins / Q000737:chemistry / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics; D011134:Polysaccharides / Q000737:chemistry / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D014026:Nicotiana / Q000166:cytology* / Q000235:genetics* / Q000378:metabolism; D014990:Xylans / Q000378:metabolism; D000099237:UDP-Galactose Translocators
D005690:Galactose; D005936:Glucans; D009004:Monosaccharide Transport Proteins; D010368:Pectins; D011134:Polysaccharides; D011994:Recombinant Proteins; D014990:Xylans; D000099237:UDP-Galactose Translocators; C029353:xyloglucan; C007916:hemicellulose
Cell wall matrix; Monosaccharide; Nucleotide sugar transporter; Transgenic plant; UDP-galactose