title: Identification of soybean purple acid phosphatase genes and their expression responses to phosphorus availability and symbiosis.
abstract: OBJECTIVE
  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.
  
  
  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.
authors.affiliation: State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Root Biology Center, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Chengchen
authors.initials: C
authors.lastname: Li
authors.forename: Shunhua
authors.initials: S
authors.lastname: Gui
authors.forename: Tao
authors.initials: T
authors.lastname: Yang
authors.forename: Thomas
authors.initials: T
authors.lastname: Walk
authors.forename: Xiurong
authors.initials: X
authors.lastname: Wang
authors.forename: Hong
authors.initials: H
authors.lastname: Liao
mesh_terms: D000135:Acid Phosphatase / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D000595:Amino Acid Sequence; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D006023:Glycoproteins / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D038821:Mycorrhizae / Q000502:physiology; D010758:Phosphorus / Q000172:deficiency* / Q000378:metabolism; D010802:Phylogeny; D010937:Plant Growth Regulators / Q000378:metabolism; D018517:Plant Roots / Q000382:microbiology; D012231:Rhizobium / Q000502:physiology; D013025:Glycine max / Q000201:enzymology* / Q000235:genetics* / Q000382:microbiology; D013559:Symbiosis
chemical_list: D006023:Glycoproteins; D010937:Plant Growth Regulators; D010758:Phosphorus; C091137:purple acid phosphatase; D000135:Acid Phosphatase