[Objective] This study aimed to investigate the protective effects of proteins, salts, sugars and trace elements on soybean rhizobium strain HW-05 by response surface methodology. [Method] Different types, combinati...[Objective] This study aimed to investigate the protective effects of proteins, salts, sugars and trace elements on soybean rhizobium strain HW-05 by response surface methodology. [Method] Different types, combinations, ratios and concentrations of protective agents were designed. Under simulated conditions, the optimal protective agent formulation was screened for improving the survival rate and survival time of soybean rhizobium strain HW-05. The optimal combination of significant factors was determined by Box-Behnken central composite design. [Result] Three significant factors affecting effective number of viable cells were screened, including peptone, xanthan gum and NaCl. The final concentration of each compound was optimized 0. 13% peptone, 0.011% xanthan gum, 0.30% NaCl. [Conclusion] After addition of protective agent and preservation at room temperature for six months, effective number of viable cells of soybean rhizobium strain HW-05 reached 3.185 ×10^8 CFU/ml. The survival rate of HW-05 cells was improved by more than 25% compared with the control group （2.458×10^8 CFU /ml）.展开更多
NORK and soybean acyl carrier protein(ACP) both play important roles in nodulation.However,the relationship between Nod factor signaling and fatty acid(FA) biosynthesis during symbiotic development is unknown.In this ...NORK and soybean acyl carrier protein(ACP) both play important roles in nodulation.However,the relationship between Nod factor signaling and fatty acid(FA) biosynthesis during symbiotic development is unknown.In this study,an RNAi plasmid of Gm NORK was constructed and transformed into soybean roots by Agrobacterium rhizogene-mediated hairy-root transformation.The nodule number decreased substantially in Gm NORK knockdown soybean transgenic roots.To investigate the relationship between Gm ACP and Nod factor signaling,we measured Gm ACP expression levels in Gm NORK RNAi soybean transgenic roots and found that rhizobia inoculation led to substantially reduced Gm ACP expression.Thus,FA biosynthesis was affected by Nod factor signaling during nodule development in soybean,a finding that provides valuable information that improves our understanding of the functions of Gm NORK and Gm ACP in symbiotic signaling and nodule development.展开更多
The cosmid gene library of Rhizobium fredii strain B52 genome was constructed,andthen a 3.7kb enhancing fragment was isolated through plant experiment,which could im-prove the symbiotic efficiency of Bradyrhizobium ja...The cosmid gene library of Rhizobium fredii strain B52 genome was constructed,andthen a 3.7kb enhancing fragment was isolated through plant experiment,which could im-prove the symbiotic efficiency of Bradyrhizobium japonicum strain 2210.The obtained higheffective strain was called HN32.It has been widely used as soybean inoculant in He-longjiang,Sichuan and Guangxi provinces with an average of 6%yield increase comparingwith 2210.The recombinant plasmid pHN32 in strain HN32 contains a 3.7kb foreign insert.Its nucleotide sequence was analyzed.Computer analysis indicated that there were two openreading frames(ORFs)within the 3.7kb enhancing fragment.ORF1 shows no homologywith known genes except the first 19 amino acids which had high homology with lactosetransferase of Agrobacterium radiobacter.ORF2 shows 54% homology with hupE of Rhizo-bium leguminosarum,and related with glycosylation transfer gene of Rhizobium meliloti.Names enfA and enfB are proposed to ORF1 and ORF2 respectively.展开更多
为了进一步研究发掘新的根瘤菌资源库,采用平板划线分离的方法从大豆根瘤中分离纯化根瘤菌,并且将获得的菌株进行盆栽回接试验,结果表明,分离获得的大豆根瘤菌菌株均可在大豆和苜蓿上结瘤,具有结瘤能力。根据已公布大豆根瘤菌共同结瘤基...为了进一步研究发掘新的根瘤菌资源库,采用平板划线分离的方法从大豆根瘤中分离纯化根瘤菌,并且将获得的菌株进行盆栽回接试验,结果表明,分离获得的大豆根瘤菌菌株均可在大豆和苜蓿上结瘤,具有结瘤能力。根据已公布大豆根瘤菌共同结瘤基因nod A、nif H、16S r DNA保守区域设计引物,并且对nod A、nif H、16S r DNA序列进行扩增分析和系统发育分析,由此鉴定分离的根瘤菌为费式中华根瘤菌,从而在分子水平上实现了对大豆根瘤菌的快速鉴定。展开更多
基金Supported by Fund of Heilongjiang Academy of Sciences
文摘[Objective] This study aimed to investigate the protective effects of proteins, salts, sugars and trace elements on soybean rhizobium strain HW-05 by response surface methodology. [Method] Different types, combinations, ratios and concentrations of protective agents were designed. Under simulated conditions, the optimal protective agent formulation was screened for improving the survival rate and survival time of soybean rhizobium strain HW-05. The optimal combination of significant factors was determined by Box-Behnken central composite design. [Result] Three significant factors affecting effective number of viable cells were screened, including peptone, xanthan gum and NaCl. The final concentration of each compound was optimized 0. 13% peptone, 0.011% xanthan gum, 0.30% NaCl. [Conclusion] After addition of protective agent and preservation at room temperature for six months, effective number of viable cells of soybean rhizobium strain HW-05 reached 3.185 ×10^8 CFU/ml. The survival rate of HW-05 cells was improved by more than 25% compared with the control group （2.458×10^8 CFU /ml）.
基金supported by the PhD Early Development Program of Yangtze University (0121)
文摘NORK and soybean acyl carrier protein(ACP) both play important roles in nodulation.However,the relationship between Nod factor signaling and fatty acid(FA) biosynthesis during symbiotic development is unknown.In this study,an RNAi plasmid of Gm NORK was constructed and transformed into soybean roots by Agrobacterium rhizogene-mediated hairy-root transformation.The nodule number decreased substantially in Gm NORK knockdown soybean transgenic roots.To investigate the relationship between Gm ACP and Nod factor signaling,we measured Gm ACP expression levels in Gm NORK RNAi soybean transgenic roots and found that rhizobia inoculation led to substantially reduced Gm ACP expression.Thus,FA biosynthesis was affected by Nod factor signaling during nodule development in soybean,a finding that provides valuable information that improves our understanding of the functions of Gm NORK and Gm ACP in symbiotic signaling and nodule development.
基金the High Technology Research and Development Programme of china.
文摘The cosmid gene library of Rhizobium fredii strain B52 genome was constructed,andthen a 3.7kb enhancing fragment was isolated through plant experiment,which could im-prove the symbiotic efficiency of Bradyrhizobium japonicum strain 2210.The obtained higheffective strain was called HN32.It has been widely used as soybean inoculant in He-longjiang,Sichuan and Guangxi provinces with an average of 6%yield increase comparingwith 2210.The recombinant plasmid pHN32 in strain HN32 contains a 3.7kb foreign insert.Its nucleotide sequence was analyzed.Computer analysis indicated that there were two openreading frames(ORFs)within the 3.7kb enhancing fragment.ORF1 shows no homologywith known genes except the first 19 amino acids which had high homology with lactosetransferase of Agrobacterium radiobacter.ORF2 shows 54% homology with hupE of Rhizo-bium leguminosarum,and related with glycosylation transfer gene of Rhizobium meliloti.Names enfA and enfB are proposed to ORF1 and ORF2 respectively.
文摘为了进一步研究发掘新的根瘤菌资源库,采用平板划线分离的方法从大豆根瘤中分离纯化根瘤菌,并且将获得的菌株进行盆栽回接试验,结果表明,分离获得的大豆根瘤菌菌株均可在大豆和苜蓿上结瘤,具有结瘤能力。根据已公布大豆根瘤菌共同结瘤基因nod A、nif H、16S r DNA保守区域设计引物,并且对nod A、nif H、16S r DNA序列进行扩增分析和系统发育分析,由此鉴定分离的根瘤菌为费式中华根瘤菌,从而在分子水平上实现了对大豆根瘤菌的快速鉴定。
