The glutathione S-transferases gene family plays an important regulatory role in growth and development,and responses to environmental change.In this study,six complete GST genes(Mp GST1,Mp GST2,Mp GST3,MpGST4,Mp GST5...The glutathione S-transferases gene family plays an important regulatory role in growth and development,and responses to environmental change.In this study,six complete GST genes(Mp GST1,Mp GST2,Mp GST3,MpGST4,Mp GST5,and Mp GST6)were cloned from the gametophytes of brown alga Macrocystis pyrifera.Subsequent bioinformatics analysis showed that these six genes encoded proteins with 202,216,288,201,205,and 201 aa,respectively.Moreover,Mp GST3 differs from the other GST genes.Phylogenetic analysis suggested that MpGST3 belongs to the Ure2p type GST.Domain analysis suggested that the other GSTs from M.pyrifera belong to the soluble GST family and form an independent branch with the GSTs found in the other macroalgae,suggesting that a new GST type was formed during macroalgal evolution.GST genes were upregulated in M.pyrifera when 2.5 mg L^(-1)Cu ions were added to the medium.Six GST genes were integrated into the genome of Synechococcus elongatus PCC 7942,and their functions were verified by measuring light absorbance,photosynthetic pigment content,and photosynthetic parameters of the transformed strains under 0.3 mg L^(-1)Cu ion stress.The results showed much higher levels of various parameters in the transformed strains than in the wild strain.The transformed strains(with the MpGST genes)showed significantly enhanced resistance to Cu ion stress,while the wild strain almost died.The results of this study lay a theoretical foundation for further research on the Cu ion stress resistance function of GSTs in M.pyrifera.展开更多
In transgenic process, a foreign gene can be integrated in the host genome in two directions, which may influence its expression. In order to study the effects of insertal orientation, the gfp reporter gene was insert...In transgenic process, a foreign gene can be integrated in the host genome in two directions, which may influence its expression. In order to study the effects of insertal orientation, the gfp reporter gene was inserted in the isiAB locus of Synechococcus sp. PCC7942 in different directions, and the GFP expression levels and the growth of the transgenic algae were compared. It was showed that the gfp gene could express in each direction, and no significant difference was detected on algal growth and GFP expression levels between the two recombinant algae.展开更多
蓝藻Synechococcussp.PCC7942 HCO3-高亲和转运蛋白操纵子基因cmpABCD是其CO2浓缩机制中的调控基因之一.本研究用携带潮霉素B磷酸转移酶基因(hygromyc in B pho transferase,hpt)筛选标记的同源双臂整合载体pUC-HATH转化蓝藻Synechococc...蓝藻Synechococcussp.PCC7942 HCO3-高亲和转运蛋白操纵子基因cmpABCD是其CO2浓缩机制中的调控基因之一.本研究用携带潮霉素B磷酸转移酶基因(hygromyc in B pho transferase,hpt)筛选标记的同源双臂整合载体pUC-HATH转化蓝藻Synechococcussp.PCC7942,以潮霉素B作为筛选试剂筛选出具潮霉素B抗性的转化藻,运用引物PCR方法证实潮霉素B磷酸转移酶基因表达盒通过质粒pUC-HATH的介导已定点插入蓝藻Synechococcussp.PCC7942基因组中,成功地构建了具有潮霉素B抗性的cmpBCD基因插入失活突变藻株.并最终通过比较野生藻Synechococcussp.PCC7942和突变藻Synechococcussp.PCC7942在不同Na2CO3浓度的改良BG-11培养基中生长特性,探讨了HCO3-高亲和转运蛋白操纵子cmpABCD基因失活对藻体生长的影响.展开更多
The unicellular cyanobacterium, Synechococcus elongatus PCC 7942(Syn7942), synthesizes sucrose as the only compatible solute under salt stress. A series of engineered Syn7942 strains for sucrose production were constr...The unicellular cyanobacterium, Synechococcus elongatus PCC 7942(Syn7942), synthesizes sucrose as the only compatible solute under salt stress. A series of engineered Syn7942 strains for sucrose production were constructed. The overexpression of the native sps(encoding a natively fused protein of sucrose phosphate synthase SPS and sucrose phosphate phosphatase SPP) in Syn7942 wild type caused a 93% improvement of sucrose productivity. The strain FL130 co-overexpressing sps and csc B(encoding a sucrose transporter) exhibited a 74% higher extracellular sucrose production than that overexpressing csc B only. Both results showed the significant improvement of sucrose productivity by the double functional protein SPS-SPP. Afterwards, FL130 was cultivated under a modified condition, and the cell-free culture medium containing 1.5 g L-1 sucrose was pre-treated with an acid hydrolysis technique. Cultivated with the neutralized hydrolysates as the starting media, two widely used microorganisms, Escherichia coli and Saccharomyces cerevisiae, showed a comparable growth with that in the control media supplemented with glucose. These results clearly demonstrated that the cell-free culture of sucrose-secreting cyanobacteria can be applied as starting media in microbial cultivation.展开更多
基金supported by the National Key R&D Program of China(No.2018YFD0900305)the National Natural Science Foundation of China(No.31770393)+5 种基金the Major Scientific and Technological Innovation Project of Shandong Provincial Key Research and Development Program(No.2019JZZY020706)the Central Public-Interest Scientific Institute Basal Research Fund,CAFS(Nos.2020TD 19 and 2020TD27)the China Agriculture Research System(CARS-50)the Taishan Scholars Funding of Shandong Provincethe Taishan Scholars Funding and Talent Projects of Distinguished Scientific Scholars in AgricultureYoung Taishan Scholars Program to DONG Xu。
文摘The glutathione S-transferases gene family plays an important regulatory role in growth and development,and responses to environmental change.In this study,six complete GST genes(Mp GST1,Mp GST2,Mp GST3,MpGST4,Mp GST5,and Mp GST6)were cloned from the gametophytes of brown alga Macrocystis pyrifera.Subsequent bioinformatics analysis showed that these six genes encoded proteins with 202,216,288,201,205,and 201 aa,respectively.Moreover,Mp GST3 differs from the other GST genes.Phylogenetic analysis suggested that MpGST3 belongs to the Ure2p type GST.Domain analysis suggested that the other GSTs from M.pyrifera belong to the soluble GST family and form an independent branch with the GSTs found in the other macroalgae,suggesting that a new GST type was formed during macroalgal evolution.GST genes were upregulated in M.pyrifera when 2.5 mg L^(-1)Cu ions were added to the medium.Six GST genes were integrated into the genome of Synechococcus elongatus PCC 7942,and their functions were verified by measuring light absorbance,photosynthetic pigment content,and photosynthetic parameters of the transformed strains under 0.3 mg L^(-1)Cu ion stress.The results showed much higher levels of various parameters in the transformed strains than in the wild strain.The transformed strains(with the MpGST genes)showed significantly enhanced resistance to Cu ion stress,while the wild strain almost died.The results of this study lay a theoretical foundation for further research on the Cu ion stress resistance function of GSTs in M.pyrifera.
基金supported Science Foundation of China by the National Natural(No.30471317).
文摘In transgenic process, a foreign gene can be integrated in the host genome in two directions, which may influence its expression. In order to study the effects of insertal orientation, the gfp reporter gene was inserted in the isiAB locus of Synechococcus sp. PCC7942 in different directions, and the GFP expression levels and the growth of the transgenic algae were compared. It was showed that the gfp gene could express in each direction, and no significant difference was detected on algal growth and GFP expression levels between the two recombinant algae.
文摘蓝藻Synechococcussp.PCC7942 HCO3-高亲和转运蛋白操纵子基因cmpABCD是其CO2浓缩机制中的调控基因之一.本研究用携带潮霉素B磷酸转移酶基因(hygromyc in B pho transferase,hpt)筛选标记的同源双臂整合载体pUC-HATH转化蓝藻Synechococcussp.PCC7942,以潮霉素B作为筛选试剂筛选出具潮霉素B抗性的转化藻,运用引物PCR方法证实潮霉素B磷酸转移酶基因表达盒通过质粒pUC-HATH的介导已定点插入蓝藻Synechococcussp.PCC7942基因组中,成功地构建了具有潮霉素B抗性的cmpBCD基因插入失活突变藻株.并最终通过比较野生藻Synechococcussp.PCC7942和突变藻Synechococcussp.PCC7942在不同Na2CO3浓度的改良BG-11培养基中生长特性,探讨了HCO3-高亲和转运蛋白操纵子cmpABCD基因失活对藻体生长的影响.
基金supported by the Joint Sino-GermanResearch Project (GZ984 to X. Lu)the Excellent Youth Award of the Shandong Natural Science Foundation (JQ201306 to X. Lu)the Shandong Taishan Scholarship (X. Lu)
文摘The unicellular cyanobacterium, Synechococcus elongatus PCC 7942(Syn7942), synthesizes sucrose as the only compatible solute under salt stress. A series of engineered Syn7942 strains for sucrose production were constructed. The overexpression of the native sps(encoding a natively fused protein of sucrose phosphate synthase SPS and sucrose phosphate phosphatase SPP) in Syn7942 wild type caused a 93% improvement of sucrose productivity. The strain FL130 co-overexpressing sps and csc B(encoding a sucrose transporter) exhibited a 74% higher extracellular sucrose production than that overexpressing csc B only. Both results showed the significant improvement of sucrose productivity by the double functional protein SPS-SPP. Afterwards, FL130 was cultivated under a modified condition, and the cell-free culture medium containing 1.5 g L-1 sucrose was pre-treated with an acid hydrolysis technique. Cultivated with the neutralized hydrolysates as the starting media, two widely used microorganisms, Escherichia coli and Saccharomyces cerevisiae, showed a comparable growth with that in the control media supplemented with glucose. These results clearly demonstrated that the cell-free culture of sucrose-secreting cyanobacteria can be applied as starting media in microbial cultivation.
