Figure 1
Responsiveness of AtPHT1 transcript levels to Pi supply. The relative abundance of AtPHT1 transcripts in roots (A) and shoots (B) of 42-day-old Arabidopsis plants that were deprived of Pi for 12 days followed by Pi resupply in hydroponics is shown. Transcript abundance was measured by qRT-PCR and expressed as 40-∆Ct, a log2 measure of the ratio of the transcript amount from the target gene to the average transcript amount from a set of reference genes (see Method). Plants were grown in nutrient solution containing 250 μM Pi for 30 d, transferred to solution without Pi for 12 d to deplete internal P pools, and then transferred to a solution containing either no added Pi (−P) or 250 μM Pi (+P). Tissues were harvested 1, 2 or 3 d (D1, D2, D3) after the start of treatments. Control (C) plants were continuously supplied with 250 μM Pi and were harvested at D1. Data points are means ± S.D. (n = 3 biological replicates of 12 plants each). Different letters indicate significantly different means (P <0.05) between the control and treatment according to one-way ANOVA and Tukey’s Multiple Comparison of Means. The –P plants and + P plants were statistically analysed as separate groups.