Pentatricopeptide repeat (PPR) proteins,containing tandem repeats of degenerate 35 amino acid motifs,are important for post-transcriptional chloroplast gene expression. In this study,we report the characterization of ...Pentatricopeptide repeat (PPR) proteins,containing tandem repeats of degenerate 35 amino acid motifs,are important for post-transcriptional chloroplast gene expression. In this study,we report the characterization of a pigment-deficient mutant 1 (pdm1) in Arabidopsis,which displays the albino phenotype. PDM1 contains 5 PPR motifs followed by a PLS domain. The levels of plastid-encoded polymerase-dependent chloroplast genes were reduced dramatically,whereas those of nucleus-encoded polymerase-dependent chloroplast genes increased in the mutant. In addition,the pattern of rpoA pre-mRNA was altered and the rpoA transcript was absent in pdm1. Thus,these results suggest that PDM1 is required for processing of rpoA pre-mRNA in Arabidop-sis.展开更多
目的分离鉴定白鹭粪便中的乳杆菌。方法使用乳杆菌PCR快速检出技术检出白鹭粪便样品中的乳杆菌。将乳杆菌的保守基因16S r DNA、rpo A和rec A克隆测序,并进行序列分析。使用细菌微量生化管和常规生化试验测定乳杆菌糖发酵产酸等生化特...目的分离鉴定白鹭粪便中的乳杆菌。方法使用乳杆菌PCR快速检出技术检出白鹭粪便样品中的乳杆菌。将乳杆菌的保守基因16S r DNA、rpo A和rec A克隆测序,并进行序列分析。使用细菌微量生化管和常规生化试验测定乳杆菌糖发酵产酸等生化特征。结果从白鹭粪便样品得到1株乳杆菌菌株FZB1,其16S r DNA基因和粪便乳杆菌AFL13-2的16S r DNA基因最相似,相似性为99.2%。Rpo A的氨基酸残基序列比对结果表明:该菌株和姬鼠乳杆菌、动物乳杆菌、鼠乳杆菌的亲缘关系最近,其相似性分别达到了97.1%、97.1%和96.7%。该菌株的Rec A氨基酸残基序列和粪便乳杆菌完全相同,和姬鼠乳杆菌、动物乳杆菌、鼠乳杆菌的Rec A氨基酸残基序列有较高的相似性,分别为91.9%、91.5%和91.5%。生化鉴定结果表明:该菌株符合乳杆菌属和粪便乳杆菌的生化特征。结论我们从中国的白鹭粪便中分离鉴定到了一株粪便乳杆菌,这是2013年在南非发现的新种。粪便乳杆菌在中国的再次发现充实了乳杆菌种质资源库,证明了粪便乳杆菌的广泛分布。展开更多
基金supported by the National Basic Research Program of China (2006CB910300)the National Natural Science Foundation of China (30725003)
文摘Pentatricopeptide repeat (PPR) proteins,containing tandem repeats of degenerate 35 amino acid motifs,are important for post-transcriptional chloroplast gene expression. In this study,we report the characterization of a pigment-deficient mutant 1 (pdm1) in Arabidopsis,which displays the albino phenotype. PDM1 contains 5 PPR motifs followed by a PLS domain. The levels of plastid-encoded polymerase-dependent chloroplast genes were reduced dramatically,whereas those of nucleus-encoded polymerase-dependent chloroplast genes increased in the mutant. In addition,the pattern of rpoA pre-mRNA was altered and the rpoA transcript was absent in pdm1. Thus,these results suggest that PDM1 is required for processing of rpoA pre-mRNA in Arabidop-sis.
文摘目的分离鉴定白鹭粪便中的乳杆菌。方法使用乳杆菌PCR快速检出技术检出白鹭粪便样品中的乳杆菌。将乳杆菌的保守基因16S r DNA、rpo A和rec A克隆测序,并进行序列分析。使用细菌微量生化管和常规生化试验测定乳杆菌糖发酵产酸等生化特征。结果从白鹭粪便样品得到1株乳杆菌菌株FZB1,其16S r DNA基因和粪便乳杆菌AFL13-2的16S r DNA基因最相似,相似性为99.2%。Rpo A的氨基酸残基序列比对结果表明:该菌株和姬鼠乳杆菌、动物乳杆菌、鼠乳杆菌的亲缘关系最近,其相似性分别达到了97.1%、97.1%和96.7%。该菌株的Rec A氨基酸残基序列和粪便乳杆菌完全相同,和姬鼠乳杆菌、动物乳杆菌、鼠乳杆菌的Rec A氨基酸残基序列有较高的相似性,分别为91.9%、91.5%和91.5%。生化鉴定结果表明:该菌株符合乳杆菌属和粪便乳杆菌的生化特征。结论我们从中国的白鹭粪便中分离鉴定到了一株粪便乳杆菌,这是2013年在南非发现的新种。粪便乳杆菌在中国的再次发现充实了乳杆菌种质资源库,证明了粪便乳杆菌的广泛分布。
