Effect Of Enhanced CO₂ And Temperature On The Transcription Of UV Damage Repair Genes In Synechocystis Sp.PCC 6803

In this study, Synechocystis sp.strain PCC 6803 was grown under five different conditions:(1) 25℃+400ppm CO2 (control); (2) 29℃+400ppm CO2 (elevated temperature); (3) 25℃+800ppm CO2 (elevated CO2 1); (4) 29℃+800ppm CO2 (greenhouse effect);(5) 25℃+1200ppm CO2 (elevated CO2 2) with SYBR Green Q-PCR and Taqman Q-PCR.The cultures were incubated for 5 weeks,15 weeks and 55 weeks before detected,about one year in total.After incubation,we determined the transciption of four genes in cyanobaterium Synechocystis sp.strain PCC 6803 for the reparation of UV damage, phrA/psbAl/psbA2/psbA3 was included.We extracted the total RNA of Synechocystis sp.strain PCC 6803, with reverse transciption synthesised cDNA,then quantitied the level of transcipts by Q-PCR,then we obtain the transcripts of them.The result indicates that,The biomass of Synechocystis sp.strain PCC 6803 can be increased with the enhanced CO2 concentration and temperature,and the pH will be improved following the biomass.On transcriptional level we discovered, when the time extended to 55th weeks, the level of transcipts among most of them significantly down regulationed,the average is about 50%;On contrast to the normal one,the changes of transcripts of them in the UV serious is more obviously;However, the down regulaotin extend,psbA2 is the most reduced one of them, the normal serious is the especial obviously;The association of temperature and CO2 concentration,we discovered that there is a antagonism in the tanscription of phrA/psbAl/psbA3.What’s more,there is a obvious response in psbAl,which was known as a "silent"gene,this demostrate that the transcription level of psbAl can changed without merely in microaerobic conditions.Moreover,the short period cultivation with increased temperature or elevated CO2 can down regulated the tanscription level of 16SrDNA,however,there were no significiant effection in the one cultivated under green house.In summary,green house will increased the biomass of Synechocystis sp.strain PCC 6803 and down regulated the transcription level of UV repaire genes.However,there need further study the comprehensive effect of the cyanobacteria growthed in open wild environment.