Abstract
Arbuscular mycorrhizal (AM) fungi establish ecologically important symbiotic associations with the majority of land plant species, allowing improved uptake of phosphate (Pi) from the soil in exchange for plant-assimilated carbohydrates. Additionally, AM fungi endow plants with tolerance to pathogens and stress. Soybean is the major leguminous crop in the world, the yield of which being 1.8 x 108 t. Investigation of molecular mechanisms of AM symbiosis is the basis to save fertilizers and chemicals.
AM-inducible Pi transporter genes in soybean have not been reported. We constructed a cDNA library of soybean AM roots. Using degenerate oligonucleotide primers, we amplified cDNA fragments for soybean Pi transporters. Then, we screened the cDNA library using not only the cDNA fragments but also Pi transporter genes of M. truncatula and L. japonicus as probes. As a result, we isolated a number of Pi transporter genes. Their phylogenetic relationship and expression patterns will be presented.
