Role of the phosphate exporter PHO1 in stomatal movements

AtPHO1 encodes a putative transmembrane protein known to be involved in root-to-shoot phosphate (Pi) transport and homeostasis. The pho1 mutant fails to load phosphate into the xylem, resulting in a plant that suffers from severe Pi deficiency symptoms. Since the expression of PHO1 is mainly localized to the vasculature of the root, research efforts to understand the role of PHO1 as a phosphate transporter have

focused on its involvement in root vessels cells. However, other cell types such as guard cells also rely heavily on ion transport for their physiology. This thesis investigates the potential importance of phosphate for guard cells and gathers genetic evidence of PHO1 s role in stomatal movements.