Molecular Cloning And Functional Analysis Of PvCO In Phyllostachys Violascens

Arabidopsis CONSTANS(CO) gene is a central regulator in the photoperiodpathway. Overexpression of CO gene accelerated flowering regardless of photoperiod.Mutation in CO gene resulted in delayed flowering under long-day condition, whereasmutation in CO had no effect on flowering time under short-day condition. Our essaymainly focused on the molecular cloning and functional analysis of PvCO inPhyllostachys violascens, here are the results.1. In our essay we have cloned two CO homologous genes from Phyllostachysviolascens named PvCO1and PvCO2, respectively. Analysis of PvCO1and PvCO2predicted proteins sequences found that both contain two tandem repeats of B-boxdomains near the N-terminus and the CCT domain near the C-terminus. Both PvCO1and PvCO2genes have two exons and one intron. The predicted proteins sequences ofPvCO1and PvCO2show70.91%identity.2. We have tested the level of expression of the two genes in spatial and temporal byRT-PCR. The expression of PvCO1existed diurnal rhythm, but PvCO2didn’t.PvCO1gene was detected high expression in leaves and next in the stems and flowerbuds and no expression in roots. PvCO2gene was only detected in immature andmature leaves but no in other tested samples. The PvCO1gene showed lowexpression before flowering time, but high expression during flowering stage, thendeclined to low expression again after blossom. However, the expression of PvCO2almost showed stable.3. Using yeast two-hybrid system, the B-box domain was involved in the interactionbetween PvCO1and14-3-3(PvGF14c).4. PvCO1and PvCO2localized in nucleus of cells. The truncated PvCO1whichcontained the CCT domain is also localization in nucleus of cells. These resultsindicated the CCT conserved domain is used as an nucleus localization signal.5. We have constructed the over-expression of PvCO1and PvCO2vectors and transfered to Arabidopsis. We preliminary found over-expression of PvCO1delayingflowering time, but over-expression of PvCO2has no influence on flowering timeduring T2transgenic Arabidopsis.