Objective:To analyse the rar gene repertoire and characterise the rhondroitin sulphate A (CSA)-binding activity of the Duffy-binding like(I)BI.) domains encoded by the var2csa gene of a Plasmodium falciparum(P.falcipa...Objective:To analyse the rar gene repertoire and characterise the rhondroitin sulphate A (CSA)-binding activity of the Duffy-binding like(I)BI.) domains encoded by the var2csa gene of a Plasmodium falciparum(P.falciparum) isolate in Hainan Province,China.Methods:The sequences of var DBL1 regions were PCR-amplified,sequenced and the sequence characteristics was bioinformalically analysed.Recombinant proteins encoded by the var2csa genes were expressed and purified.The binding activities of the recombinant proteins to CSA receptor was detected by ELISA assays.Results:Fifty six unique DBI.a sequences were obtained,and the sequences represented similar diversity to the var genes of the genome parasite 3D7.There are two var2csa genes in the P.falciparum isolated from Hainan Province.Unlike in other falciparum parasites such as HB3,the two var2csa genes are more diverged.The receptor-binding capacity of DBL-5εand DBI.-6 e domains of HN var2CSA was studied.Conclusions:This work represented the diversity of rar genes of a P.falciparum isolate in China.展开更多
Syringa species are important ornamentals with strong floral scent,of which monoterpenes are the main component.In this study,a new monoterpene synthase gene,named SoLIM,was collected from the flowers of Syringa oblat...Syringa species are important ornamentals with strong floral scent,of which monoterpenes are the main component.In this study,a new monoterpene synthase gene,named SoLIM,was collected from the flowers of Syringa oblata and S.oblata var.alba using a homologous cloning method.The full-length cDNA of SoLIM was1746 bp and encoded 581 amino acids.Sequence analysis showed that SoLIM contained the DDxxD and RRx8 W motifs,which are two typical conserved monoterpene synthase motifs,and was thus classified as belonging to the Tpsb subfamily.Using quantitative reverse-transcription PCR,SoLIM was significantly expressed in the petals and pistils of S.oblata and S.oblata var.alba,respectively.SoLIM expression peaked earlier than the D-limonene emissions in the diurnal experiments,but occurred later when D-limonene had peaked during the flowering phase,indicating that differences in SoLIM gene expression and D-limonene emissions existed.The synthesis of floral scent is thus associated with diverse regulatory mechanisms that require further investigation.展开更多
Codon usage bias(CUB) is a unique property of genome which refers to non-random usage of synonymous codons in coding sequences. The present study makes an attempt to find out the pattern of CUB in chloroplast(cp) gene...Codon usage bias(CUB) is a unique property of genome which refers to non-random usage of synonymous codons in coding sequences. The present study makes an attempt to find out the pattern of CUB in chloroplast(cp) genes among three tea species, i.e., Camellia sinensis var. assamica(Assam tea), Camellia sinensis var. sinensis(Chinese tea) and Camellia pubicosta(wild tea species) as no work on CUB was reported earlier. To understand the patterns of codon usage among the cp genes of three tea groups, we used bioinformatic tools to investigate the protein coding sequences of cp genes. In our present study, the mean nucleobase T was the highest whereas C was the lowest in all the three tea groups. The overall AT content was more than GC content, i.e., genes were AT rich. The scaled chi-square(SCS) value indicated that the CUB of cp genes was low. The codon CGT(Arg) was over-represented in C. sinensis var. sinensis whereas GGA(Pro) was over-represented in C. pubicosta species. Heatmap study revealed that most of the GC ending codons showed positive correlations between codon usage and GC3 while AT ending codons exhibited negative correlations. From neutrality plot analysis, it was evident that natural selection had played a major role, while mutation pressure exerted a minor effect in the CUB of cp genes in three tea groups. Highly significant(P<0.01) positive correlation was found between SCS and synonymous codon usage order(SCUO) of cp genes which suggested that high expression of cp genes was associated with high degree of CUB.展开更多
The possibility of gene flow between two varieties of transgenic rice with bar gene (Y0003 and 99-t) (male) and barnyard grass(Echinochloa crusgalli var. mitis ) (female) was studied by means of reproductive biology. ...The possibility of gene flow between two varieties of transgenic rice with bar gene (Y0003 and 99-t) (male) and barnyard grass(Echinochloa crusgalli var. mitis ) (female) was studied by means of reproductive biology. The germination and growth of rice pollen grains on barnyard grass stigmas at 30 min, and 1-4 h after crossing by hand were observed with an optical microscope. The results were compared with the germination and growth of barnyard grass pollen grains at the corresponding time after self-pollination. The results showed that germination and growth of the pollen grains of the two varieties were similar on barnyard grass stigmas, but differed significantly from self-pollination of barnyard grass. Pollen grains germinated and pollen tubes penetrated stigmas normally, and the number of pollen grains being condensing or releasing their inclusions or having released them increased with the time after self-pollination. Pollen grains of transgenic rice on the stigmas of barnyard grass couldn't germinate or grow normally after crossing, neither could they penetrate the stigmas of barnyard grass. Therefore, it could be concluded that the sexual incompatibility between transgenic rice with bar gene and barnyard grass is due to the rice pollen being unable to penetrate the stigma of barnyard grass. Further proof of incompatibility lies in the fact that the emasculated barnyard grass pollinated with the rice pollen grains could not seed.展开更多
Five commonly-used reference genes： ACT （actin）, UBE （ubiquitin-conjugating enzyme）, RPL2 （ribosomal protein L2）, BRP II （RNA polymerase II subunit）, and NADH （nicotinamide adenine dinucleotide） were examin...Five commonly-used reference genes： ACT （actin）, UBE （ubiquitin-conjugating enzyme）, RPL2 （ribosomal protein L2）, BRP II （RNA polymerase II subunit）, and NADH （nicotinamide adenine dinucleotide） were examined using geNorm software as reference genes for RT-qPCR. Among the tested reference genes, ACT and UBE were the most stable in all samples. In parallel, expression analysis of nitrilases in Brassica juncea var. tumida, was performed to preliminarily investigate the molecular interactions between nitrilase and clubroot development at 10, 15, 20, 25, 30, and 40 d postinoculation （dpi） with a suspension of resting spores of Plasmodiophora brassicae. The results showed that different gene expressions of nitrilases were regulated during the initial periods of clubroot development. The expression level of BjNIT1 increased sharply from 20 to 40 dpi in infected roots while there were no remarkable changes in healthy roots. From 15 to 30 dpi, the expression levels of BjNIT2 and BjNIT4 in infected roots were lower than those in non-infected roots. Finally, BjNIT2 in treatment was down approximately to control at 40 dpi. Our results suggest that BjNIT1, which promoted overproductions of auxin, might be involved in P. brassicae infection of B. juncea.展开更多
Using genomic DNA of bolting-tolerant lettuce as a template,flanking fragments of lettuce plastid rpo A gene were amplified and cloned by PCR. Targeting the sites of these two fragments,homologous recombinant fragment...Using genomic DNA of bolting-tolerant lettuce as a template,flanking fragments of lettuce plastid rpo A gene were amplified and cloned by PCR. Targeting the sites of these two fragments,homologous recombinant fragments of exogenous gene were integrated to construct lettuce plastid expression vector p Brpo AGFP,which harbored the expression cassette Prrn-gfp-aad A-Tpsb A. The results showed that the amplified flanking fragments were 1.2 and 1.1 kb in size. After sequencing,restriction digestion,ligation and transformation,lettuce plastid expression vector containing expression cassette Prrn-gfp-aad A-Tpsb A was constructed and confirmed by SDS-PAGE electrophoresis. The results of SDS-PAGE electrophoresis indicated that gfp gene was efficiently expressed under the regulation of plasmid specific promoter Prrn and terminator Tpsb A. GFP accounted for 45. 6% of total soluble proteins; inclusion bodies accounted for 47.5 % of bacterial proteins,which reached relatively high expression levels. The construction of lettuce plastid expression vector p Brpo A-GFP laid a solid foundation for establishment of subsequent lettuce plastid transformation system and genetic improvement of lettuce using various functional genes.展开更多
基金supports to Q.Chen from the National Basic Research Program of China(973 Program,No.2007CB513100)national science and technology project(2008ZX-10004-011)NSFC grant to J.Yin (30771886),N.Jiang(81171592,)and Q.Chen(81130033)
文摘Objective:To analyse the rar gene repertoire and characterise the rhondroitin sulphate A (CSA)-binding activity of the Duffy-binding like(I)BI.) domains encoded by the var2csa gene of a Plasmodium falciparum(P.falciparum) isolate in Hainan Province,China.Methods:The sequences of var DBL1 regions were PCR-amplified,sequenced and the sequence characteristics was bioinformalically analysed.Recombinant proteins encoded by the var2csa genes were expressed and purified.The binding activities of the recombinant proteins to CSA receptor was detected by ELISA assays.Results:Fifty six unique DBI.a sequences were obtained,and the sequences represented similar diversity to the var genes of the genome parasite 3D7.There are two var2csa genes in the P.falciparum isolated from Hainan Province.Unlike in other falciparum parasites such as HB3,the two var2csa genes are more diverged.The receptor-binding capacity of DBL-5εand DBI.-6 e domains of HN var2CSA was studied.Conclusions:This work represented the diversity of rar genes of a P.falciparum isolate in China.
基金supported by the Project of Construction of Innovative Teams and Teacher Career Development for Universities and Colleges under Beijing Municipality(IDHT20180509)the National Natural Science foundation of China(31201645)+1 种基金the Beijing Municipal Natural Science Foundation(6172006)key project of Beijing Municipal Education Commission(KZ201510020021)
文摘Syringa species are important ornamentals with strong floral scent,of which monoterpenes are the main component.In this study,a new monoterpene synthase gene,named SoLIM,was collected from the flowers of Syringa oblata and S.oblata var.alba using a homologous cloning method.The full-length cDNA of SoLIM was1746 bp and encoded 581 amino acids.Sequence analysis showed that SoLIM contained the DDxxD and RRx8 W motifs,which are two typical conserved monoterpene synthase motifs,and was thus classified as belonging to the Tpsb subfamily.Using quantitative reverse-transcription PCR,SoLIM was significantly expressed in the petals and pistils of S.oblata and S.oblata var.alba,respectively.SoLIM expression peaked earlier than the D-limonene emissions in the diurnal experiments,but occurred later when D-limonene had peaked during the flowering phase,indicating that differences in SoLIM gene expression and D-limonene emissions existed.The synthesis of floral scent is thus associated with diverse regulatory mechanisms that require further investigation.
文摘Codon usage bias(CUB) is a unique property of genome which refers to non-random usage of synonymous codons in coding sequences. The present study makes an attempt to find out the pattern of CUB in chloroplast(cp) genes among three tea species, i.e., Camellia sinensis var. assamica(Assam tea), Camellia sinensis var. sinensis(Chinese tea) and Camellia pubicosta(wild tea species) as no work on CUB was reported earlier. To understand the patterns of codon usage among the cp genes of three tea groups, we used bioinformatic tools to investigate the protein coding sequences of cp genes. In our present study, the mean nucleobase T was the highest whereas C was the lowest in all the three tea groups. The overall AT content was more than GC content, i.e., genes were AT rich. The scaled chi-square(SCS) value indicated that the CUB of cp genes was low. The codon CGT(Arg) was over-represented in C. sinensis var. sinensis whereas GGA(Pro) was over-represented in C. pubicosta species. Heatmap study revealed that most of the GC ending codons showed positive correlations between codon usage and GC3 while AT ending codons exhibited negative correlations. From neutrality plot analysis, it was evident that natural selection had played a major role, while mutation pressure exerted a minor effect in the CUB of cp genes in three tea groups. Highly significant(P<0.01) positive correlation was found between SCS and synonymous codon usage order(SCUO) of cp genes which suggested that high expression of cp genes was associated with high degree of CUB.
基金the Ministry ofScience and Technology,P.R.ChinaEvaluation of Safety of Transgenic Crops(E200102).
文摘The possibility of gene flow between two varieties of transgenic rice with bar gene (Y0003 and 99-t) (male) and barnyard grass(Echinochloa crusgalli var. mitis ) (female) was studied by means of reproductive biology. The germination and growth of rice pollen grains on barnyard grass stigmas at 30 min, and 1-4 h after crossing by hand were observed with an optical microscope. The results were compared with the germination and growth of barnyard grass pollen grains at the corresponding time after self-pollination. The results showed that germination and growth of the pollen grains of the two varieties were similar on barnyard grass stigmas, but differed significantly from self-pollination of barnyard grass. Pollen grains germinated and pollen tubes penetrated stigmas normally, and the number of pollen grains being condensing or releasing their inclusions or having released them increased with the time after self-pollination. Pollen grains of transgenic rice on the stigmas of barnyard grass couldn't germinate or grow normally after crossing, neither could they penetrate the stigmas of barnyard grass. Therefore, it could be concluded that the sexual incompatibility between transgenic rice with bar gene and barnyard grass is due to the rice pollen being unable to penetrate the stigma of barnyard grass. Further proof of incompatibility lies in the fact that the emasculated barnyard grass pollinated with the rice pollen grains could not seed.
基金financially supported by the Natural Science Foundation of Chongqing Science and Technology Commission,China (2008BB1370)Fuling Agricultural Science Institute of Chongqing,China
文摘Five commonly-used reference genes： ACT （actin）, UBE （ubiquitin-conjugating enzyme）, RPL2 （ribosomal protein L2）, BRP II （RNA polymerase II subunit）, and NADH （nicotinamide adenine dinucleotide） were examined using geNorm software as reference genes for RT-qPCR. Among the tested reference genes, ACT and UBE were the most stable in all samples. In parallel, expression analysis of nitrilases in Brassica juncea var. tumida, was performed to preliminarily investigate the molecular interactions between nitrilase and clubroot development at 10, 15, 20, 25, 30, and 40 d postinoculation （dpi） with a suspension of resting spores of Plasmodiophora brassicae. The results showed that different gene expressions of nitrilases were regulated during the initial periods of clubroot development. The expression level of BjNIT1 increased sharply from 20 to 40 dpi in infected roots while there were no remarkable changes in healthy roots. From 15 to 30 dpi, the expression levels of BjNIT2 and BjNIT4 in infected roots were lower than those in non-infected roots. Finally, BjNIT2 in treatment was down approximately to control at 40 dpi. Our results suggest that BjNIT1, which promoted overproductions of auxin, might be involved in P. brassicae infection of B. juncea.
基金Supported by Natural Science Foundation of Yunnan Province(2011FB049)National Natural Science Foundation of China(31260481,31460516)+2 种基金Fund of Yunnan Education Department(2013Y251)Fund of the Department of Life Science and Technology,Kunming University(GXKM201505)Talent Fund for PhD(YJL11015)
文摘Using genomic DNA of bolting-tolerant lettuce as a template,flanking fragments of lettuce plastid rpo A gene were amplified and cloned by PCR. Targeting the sites of these two fragments,homologous recombinant fragments of exogenous gene were integrated to construct lettuce plastid expression vector p Brpo AGFP,which harbored the expression cassette Prrn-gfp-aad A-Tpsb A. The results showed that the amplified flanking fragments were 1.2 and 1.1 kb in size. After sequencing,restriction digestion,ligation and transformation,lettuce plastid expression vector containing expression cassette Prrn-gfp-aad A-Tpsb A was constructed and confirmed by SDS-PAGE electrophoresis. The results of SDS-PAGE electrophoresis indicated that gfp gene was efficiently expressed under the regulation of plasmid specific promoter Prrn and terminator Tpsb A. GFP accounted for 45. 6% of total soluble proteins; inclusion bodies accounted for 47.5 % of bacterial proteins,which reached relatively high expression levels. The construction of lettuce plastid expression vector p Brpo A-GFP laid a solid foundation for establishment of subsequent lettuce plastid transformation system and genetic improvement of lettuce using various functional genes.
