ABSTRACT

We may realize that hexoses formed at the root/fungus interface are equally accessible to both fungal and plant monosaccharide transporters. As stated above, monosaccharide transporter from the ectomycorrhizal fungus Amanita muscaria has been characterized. It gets upregulated, leading to increase in hexose uptake capacity of the fungal partner. To characterize host (Picea abies) monosaccharide transporter, nucleotide sequences from known plant hexose transporters were matched (Nehls et al. 2000). A full-length clone from plant host denoted as PaMSTI was identified. The entire cDNA codes for a protein with 513 amino acids. It revealed the best homology with H+/monosaccharide transporters from Arabidopsis, Saccharum and Ricinus. The PaMSTI was expressed highly in the hypocotyls. However, mycorrhiza formation leads to a decrease in the PaMSTI expression in spruce seedlings. The PaMSTI gene, along with fungal monosaccharide transporters, seems to play crucial role in carbon allocation between symbionts.