InterPro domain: IPR034092

This region has been named the SPX domain after (Syg1, Pho81 and XPR1). The domain is found at the amino terminus of a variety of proteins. The PHO1 gene family conserved in plants is involved in a variety of processes, most notably the transport of inorganic phosphate from the root to the shoot of the plant and mediating the response to low levels of inorganic phosphate [ 1 ]. PHO1 may play roles in stress response as well as the stomatal response to abscisic acid [ 2 ].

1. Uncoupling phosphate deficiency from its major effects on growth and transcriptome via PHO1 expression in Arabidopsis. Plant J. 65, 557-70
2. PHO1 expression in guard cells mediates the stomatal response to abscisic acid in Arabidopsis. Plant J. 72, 199-211