Genome-wide Identification, Characterization, and Expression Analysis of PHT1 Phosphate Transporters in Wheat.

The PHT1 family of phosphate (Pi) transporters mediates phosphorus (P) uptake and re-mobilization in plants. A genome-wide sequence analysis of genes in wheat () was conducted, and their expression locations and responses to P availability were further investigated. We cloned 21 genes from the homologous alleles at to through screening a BAC library and amplifying genomic sequences. The TaPHT1 transporters were clustered into five branches in the phylogenetic tree of PHT1 proteins, and the genes from a given branch shared high similarities in sequences, expression locations, and responses to P availability. The seven tested genes all showed Pi-transport activity in yeast () cells grown under both low Pi and high Pi conditions. The expression of ./, and were root specific. The expression of these genes at flowering positively correlated with P uptake after stem elongation across three P application rates and two wheat varieties in a field experiment. Therefore, modification of expression may improve P use efficiency in a broad regime of P availability.