HIGH-AFFINITY PHOSPHATE TRANSPORTER GENES OF ARABIDOPSIS-THALIANA (REPRINTED FROM PLANT NUTRITION FOR SUSTAINABLE FOOD-PRODUCTION AND ENVIRONMENT, 1997)

In our previous study, we isolated a high-affinity phosphate transport er gene, named PNT1, from Arabidopsis thaliana, and showed i) that exp ression of the gene at high levels in tobacco cultured cells increased the rate of phosphate uptake, and ii) that the transgenic cells exhib ited increased biomass production when the supply of phosphate was lim ited (Mitsukawa et al., 1997 Proc. Natl. Acad. Sci. USA, 94, 7098-7102 ). In this study, two genes highly homologous to PHT1, named PHT2 and PHT3, were isolated from genomic DNA libraries. Nucleotide sequence co mparison indicated conservation of the second intron sequence of PHT1 in PHTZ. These three genes located closely on chromosome 5, indicating that they are not allelic with previously identified phosphate mutant loci pho1 and pho2, found on chromosome 2 and 3, respectively.