Expression signatures of Arabidopsis thaliana roots under low or high phosphate conditions.

To cope with limiting phosphorus (P) availability, plants have evolved a series of mechanisms to recycle internal P sources and to acquire P from the soil. One of these mechanisms is the release of low-molecular weight carboxylates, such as malate, which helps to liberate phosphate desorbed to aluminum and iron oxides. As malate release into the rhizosphere and root apopplast also increases iron availability. To identity genes involved in this interaction, we investigated time-dependent changes in the transcriptome of Arabidopsis thaliana roots exposed to sufficient and deficient phoshate levels . Gene expression of Arabidopsis thaliana root tissues was measured after transferring seven-day-old seedlings for 0, 1, 2, 4 and 6 days to 625 µM phosphate (sufficient P; control) or 100 µM phosphate (P-deficient condition). Three biological replicates were used.