论文部分内容阅读
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(Pi)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 Pi starvation.Increased transcription of PvPS2:1 in response to Pi starvation was further verified through histochemical analysis of PvPS2:1 promoter fusion B-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 Pi 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 Pi starvation,and could be further targeted as a candidate gene to improve crop P efficiency.
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 (Pi) starvation in the two bean genotypes, G19833 (a P -efficient genotype) and DOR364 (a P-inefficient genotype) .Wow, G19833 exhibited higher PvPS2: 1 expression levels than DOR364 in both leaves and roots during Pi starvation. Increased transcription of PvPS2: 1 in response to Pi starvation was further verified through histochemical analysis of PvPS2: 1 promoter fusion B-glucuronidase (GUS) in transgenic Arabidopsis plants. Analysis of PvPS2: 1 overexpression lines in bean hairy roots and Arabidopsis s howed that PvS2: 1 was involved in root growth and P accumulation. Fluorrthermore, expression levels of two Pi starvation responsive genes were upregulated and the APase activities were enhanced in the overexpressing PvPS2: 1 Arabidopsis lines. Together, our results strongly suggest that PvPS2 : 1 positively regulated plant responses to Pi starvation, and could be further targeted as a candidate gene to improve crop P efficiency.