Os01g0776600

Although PAP protein sequences display high levels of similarity, their functions and modes of regulation vary considerably. Using in-gel activity assays, we were able to show that the induction of APase activity by Pi deficiency is predominantly attributed to the increased expression of OsPAP10a, which is under the control of OsPHR2, the central transcription factor controlling Pi homeostasis in rice. Overexpression of OsPAP10ain rice increased shoot and root-associated APase activities in both Pi-replete and Pi-deficient conditions. As a consequence, the transgenic plants were able to hydrolyze extracellular organic P sources, such as ATP, into an inorganic form more efficiently than WT plants. However, substrate specificity still needs to be investigated.

Annotated Information

Function

OsPAP10a is a major APase isoform in both shoot and root protein extracts, and is specifically induced by Pi-deficient conditions. OsPAP10acan be secreted and that overexpression of OsPAP10ais associated with improved hydrolysis capacity of external organic P and thus better phosphate use efficiency.

Expression

The expression of OsPAP10a is induced by Pi deprivation, other nutrient stresses had no or little influence on the expression of OsPAP10a. Pi starvation highly induced the level of expression of OsPAP10a in wild type (WT) plants. In OsPAP10a-overexpressing plants, OsPAP10atranscript abundance was higher in both Pi-sufficient and deficient conditions than it was in WT plants (Figure 3A). Interestingly, the transcript level of OsPAP10ain OsPAP10aoverexpressing plants grown under Pi-replete conditions was even higher than that in WT plants grown under Pi-deficient conditions.

Evolution

In plants, the PAP family has been previously classified into seven groups and OsPAP10abelongs to group Ia. In rice, group Ia contains 5 members, namely OsPAP10a to OsPAP10d, and OsPAP26.

Labs working on this gene

Phylogenetic and expression analysis

Protein extraction and APase activity assay

Reverse transcript PCR (RT-PCR)

In-Gel APase activity staining

Root-associated acid phosphatase activity assay

References

Tian J, Wang C, Zhang Q, He X, Whelan J, Shou H(2012) Overexpression ofOsPAP10a, a root-associated acid phosphatase, increased extracellular organic phosphorus utilization in rice.J. Integr. Plant Biol.54(9), 631–639.

Zhang Q, Wang C, Tian J, Li K, Shou H(2011) Identification of rice purple acid phosphatases related to phosphate starvation signalling. Plant Biol.13,7–15.