Although secondary cell wall of plant woody cells is the largest biomass on land, the accumulation mechanism is poorly understood. Recent studies reported that arabinogalactan proteins (AGPs) play a key role in the mechanism. However, the existence of vast amount of sugar chains on AGP disturbs our molecular analyses. We formulated a hypothesis that a monosaccharide composition of the sugar chains is involved in the AGP function, and are carrying out a study into a relationship between monosaccharide composition and phenotype using genetic modified plants.
There is really a call for genetic modified plants which have a high activity of carbon dioxide fixation and increased biomass in a low-carbon society.
We found that genetic modified plants over-expressing a human UDP-galactose transporter gene (hUGT1) displayed an increased cell wall thickness, and their AGPs were hyper-galactosylated. These results indicated that the monosaccharide composition of AGP is involved in the cell wall thickness.
There are little reports that an increase of cell wall thickness was found on genetic modified plants transformed by genes responsible for cell wall biosynthesis such as cellulose synthase up to the present. Our technology is broadly applicable to many plant species for increase of biomass by thickening of the cell wall.
Khalil et al., The impact of the overexpression of human UDP-galactose transporter gene hUGT1 in tobacco plants. J. Biosci. Bioeng., 109, 159-169 (2010).