Submitted to: Annals Of Botany
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/12/2011
Publication Date: N/A
Citation: Interpretive Summary: Acid phosphatases are a family of enzymes that break chemical bonds between phosphate and the rest of the molecule. This allows for acquisition or recycling of phosphate. Some members of this enzyme family act within the plant for recycling phosphate among organic compounds, while others are active externally, where they are important for acquisition of phosphate from organic components of soil. This research identifies members of this family in soybean and reports on where they are active, as well as which members are regulated by phosphorus availability. It is important to understand the location and regulation of activity, so that we can appropriately target members where necessary. For example, to produce beans that grow better in soils with low phosphorus availability, it will likely be more beneficial to target the expression of one of the members that acts in the soil, and not one that acts internally.
Technical Abstract: Background and Aims Purple acid phosphatases (PAPs) are members of the metallo-phosphoesterase family and have been known to play important roles in phosphorus (P) acquisition and recycling in plants. Low P availability is a major constraint to growth and production of soybean, Glycine max. Comparative studies on structure, transcription regulation and responses to phosphate (Pi) deprivation of the soybean PAP gene family should facilitate further insights into the potential physiological roles of GmPAPs. Methods BLAST searches were performed to identify soybean PAP genes at the phytozome website. Bioinformatic analyses were carried out to investigate their gene structure, conserve motifs and phylogenetic relationships. Hydroponics and sand culture experiments were carried out to obtain the plant materials. Quantitative real-time PCR was employed to analyse the expression patterns of PAP genes in response to P deficiency and symbiosis. Key Results In total, 35 PAP genes were identified from soybean genomes, which can be classified into three distinct groups including six subgroups in the phylogenetic tree. The expression pattern analysis showed flowers possessed the largest number of tissue-specific GmPAP genes under normal P conditions. The expression of 23 GmPAPs was induced or enhanced by Pi starvation in different tissues. Among them, nine GmPAP genes were highly expressed in the Pi-deprived nodules, whereas only two GmPAP genes showed significantly increased expression in the arbuscular mycorrhizal roots under low-P conditions. Conclusions Most GmPAP genes are probably involved in P acquisition and recycling in plants. Also we provide the first evidence that some members of the GmPAP gene family are possibly involved in the response of plants to symbiosis with rhizobia or arbuscular mycorrhizal fungi under P-limited conditions.