Expression and functional analysis of FaPH01;H9 gene of strawberry (Fragariaxananassa)

Although the phosphate 1 (PHO1) gene family has been implicated in inorganic phosphate transport and homeostasis, the underlying mechanism of this gene in the strawberry has not yet been revealed. In the present study, we analyzed the expression of the PH01;H9 gene in the strawberry (Fragariaxananassa), revealing the involvement of this gene in the regulation of phosphorus (P) content. The coding sequence (CDS) of the PH01;H9 gene, was isolated from the cultivated strawberry 'Sachinoka' and named as FaPH01;H9. The full-length CDS of this gene was 2292 bp, encoding 763 amino acids, and the protein contained both SYG1/Pho81/XPR1 (SPX) and ERD1/XPR1/SYG1 (EXS) domains, which were involved in phosphate (Pi) signaling. Real-time reverse transcription-polymerase chain reaction (RT-PCR) data suggested that the level of FaPHO1;H9 expression was consistent with the P content in different organs, except for the petiole. Particularly, its expression level was also correlated with P content in fruits of different developmental stages. The expression of FaPHO1;H9 was also consistent with P content in leaves under different concentrations of P fertilizer application. Furthermore, transgenic Arabidopsis lines were generated, and the P content in Arabidopsis plants over-expressing FaPH01;H9 was significantly higher than that in wild-type plants. Therefore, we proposed that FaPH01;H9 functions in P transport.