title: Characterization of two putative protein phosphatase genes and their involvement in phosphorus efficiency in Phaseolus vulgaris.
abstract: Protein dephosphorylation mediated by protein phosphatases plays a major role in signal transduction of plant responses to environmental stresses. In this study, two putative protein phosphatases, PvPS2:1 and PvPS2:2 were identified and characterized in bean (Phaseolus vulgaris). The two PvPS2 members were found to be localized to the plasma membrane and the nucleus by transient expression of PvPS2:GFP in onion epidermal cells. Transcripts of the two PvPS2 genes were significantly increased by phosphate (P(i) ) starvation in the two bean genotypes, G19833 (a P-efficient genotype) and DOR364 (a P-inefficient genotype). However, G19833 exhibited higher PvPS2:1 expression levels than DOR364 in both leaves and roots during P(i)  starvation. Increased transcription of PvPS2:1 in response to P(i)  starvation was further verified through histochemical analysis of PvPS2:1 promoter fusion ß-glucuronidase (GUS) in transgenic Arabidopsis plants. Analysis of PvPS2:1 overexpression lines in bean hairy roots and Arabidopsis showed that PvS2:1 was involved in root growth and P accumulation. Furthermore, expression levels of two P(i)  starvation responsive genes were upregulated and the APase activities were enhanced in the overexpressing PvPS2:1 Arabidopsis lines. Taken together, our results strongly suggested that PvPS2:1 positively regulated plant responses to P(i)  starvation, and could be further targeted as a candidate gene to improve crop P efficiency.
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: Cui-Yue
authors.initials: CY
authors.lastname: Liang
authors.forename: Zhi-Jian
authors.initials: ZJ
authors.lastname: Chen
authors.forename: Zhu-Fang
authors.initials: ZF
authors.lastname: Yao
authors.forename: Jiang
authors.initials: J
authors.lastname: Tian
authors.forename: Hong
authors.initials: H
authors.lastname: Liao
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D017930:Genes, Reporter; D005966:Glucuronidase; D027805:Phaseolus / Q000201:enzymology / Q000235:genetics*; D010749:Phosphoprotein Phosphatases / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D010758:Phosphorus / Q000378:metabolism*; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D010758:Phosphorus; D010749:Phosphoprotein Phosphatases; D005966:Glucuronidase