Complete Genome Sequencing Of A Cyanophage And The Influence Of Elevated P CO₂ And Warming On The Transcription Of UV-damage Repair Genes Of Synechocystis Sp.6803

In this study,genome sequencing of whole genome of cyanophage S-ESS1 was carried out,and the whole genome information of cyanophage S-ESS1 was analyzed.By setting up Synechocystis sp.6803 under five different environmental conditions: 1)25 ? + 400 ppm pCO₂?CK group?,?2?29.8 ? + 400 ppm pCO₂?temperature rising group?,?3?25 ? + 670 ppm pCO₂?pCO₂ elevated group 1?,?4?25 ? + 936 ppm pCO₂?pCO₂ elevated group 2?and?5?29.8 ? + 936 ppm pCO₂?greenhouse effect group?.The growth and the PSII photochemical efficiency of Synechocystis sp.6803 were measured,revealing greenhouse effect on biomass of Synechocystis sp.6803.The effects of elevated temperature and pCO₂ on the transcription level of Synechocystis sp.6803 gene were investigated by detection of mRNA transcriptase expression.We selected seven targeted target genes,mainly covering DNA UV-damage repairing gene photo-repair gene.Then we designed and tested part RT-qPCR primers of above-mentioned Synechocystis sp.6803 DNA UV-damage repair gene.Differences in the respective expression of target gene under different experimental conditions were measured by RT-qPCR.The results show: 1,Cyanophage S-ESS1 belongs to cyanosiphovirus,whole genome information showed that it had a high degree of genetic diversity.2,In temperature rise group,pCO₂ increased in group 1?670ppm?,pCO₂ increased group 2?936ppm?and greenhouse effect group,biomass of Synechocystis sp.6803 respectively increased by 7.74%,13.37%,19.40% and 25.82%,compared with CK group.While the PSII photochemical efficiency was not effected.The results showed that with the increase of temperature,high pCO₂ and combined effect of both,the expression of recA gene expression was increased by 60%-90%.The lexA gene expression decreased about 50%with the increase of the temperature,With the increase of pCO₂,the expression of lexA increased first and then increased,and the combination of high temperature and high pCO₂ didn't effect the expression of lexA.The expression of uvrA gene increased significantly with the increase of temperature,and the elevated pCO₂ had no significant effect on the expression of uvrA.The combination of high temperature and high pCO₂ could also lead to a significant gene expression increasing of uvrA;The expression of DNA UV-damage expression of psbA1 wasn't effected by high temperature either combination of high temperature and high pCO₂ but decreased about 30% at pCO₂ 936 ppm.Temperature plays a dominant role in affecting gene expression.The results indicated that the biomass of Synechocystis sp.6803 increased sharply with the increase of greenhouse effect,and the expression of DNA UV-damage repair related genes of Synechocystis sp.6803 were significantly changed,So the ability of UV-damage repair may change,and thus will affect its ecological function.