Fig. 5.

(A) Root-associated APase activity of the rice wild-type (WT) and of transgenic plants with OsPAP10c driven by the constitutive ubiquitin promoter (UP) or the native promoter (NP) grown either with or without Pi, or with ATP as the only source of P. (B) Concentration of free Pi in the growth solution for plants grown with ATP. Germinated seeds were grown in normal nutrient solution for 15 d and then transferred to solution either with or without Pi, or containing 0.1 mM ATP as the only source of P. Root-associated APase activities were measured after 10 d treatments. Data are means (±SEM) of three replicates. Significant differences compared with the WT were determined using Turkey’s test (*P<0.05; **P<0.01; ***P<0.001).