High-affinity phosphate transporter genes of Arabidopsis thaliana

Abstract

In our previous study, we isolated a high-affinity phosphate transporter gene, named PHT1, from Arabidopsis thaliana, and showed i) that expression of the gene at high levels in tobacco cultured cells increased the rate of phosphate uptake, and ii) that the transgenic cells exhibited increased biomass production when the supply of phosphate was limited (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 comparison indicated conservation of the second intron sequence of PHT1 in PHT2. 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.