TY - JOUR
T1 - Identification of mesorhizobium loti genes relevant to symbiosis by using signature-tagged mutants
AU - Borjigin, Naoganchaolu
AU - Furukawa, Keisuke
AU - Shimoda, Yoshikazu
AU - Tabata, Satoshi
AU - Sato, Shusei
AU - Eda, Shima
AU - Minamisawa, Kiwamu
AU - Mitsui, Hisayuki
PY - 2011
Y1 - 2011
N2 - Signature-tagged mutagenesis was applied to Mesorhizobium loti, a nitrogen-fixing root-nodule symbiont of the leguminous plant Lotus japonicus. We arranged 1,887 non-redundant mutant strains of M. loti into 75 sets, each consisting of 24 to 26 strains with a different tag in each strain. These sets were each inoculated en masse onto L. japonicus plants. Comparative analysis of total DNA extracted from inoculants and resulting nodules based on quantitative PCR led to the selection of 69 strains as being reduced in relative abundance during nodulation. Plant assays conducted with individual strains confirmed that 3 were defective in nodulation (Nod-) and that 10 were Nod+but defective in nitrogen fixation (Fix-); in each case, the symbiosis deficiency could be attributed to the transposon insertion carried by that strain. Although the remaining 56 strains were Fix+, 33 of them showed significantly reduced competitiveness during nodulation. Among the mutants we identified are known genes that are diverse in predicted function as well as some genes of unknown function, which demonstrates the validity of this screening procedure for functional genomics in rhizobia.
AB - Signature-tagged mutagenesis was applied to Mesorhizobium loti, a nitrogen-fixing root-nodule symbiont of the leguminous plant Lotus japonicus. We arranged 1,887 non-redundant mutant strains of M. loti into 75 sets, each consisting of 24 to 26 strains with a different tag in each strain. These sets were each inoculated en masse onto L. japonicus plants. Comparative analysis of total DNA extracted from inoculants and resulting nodules based on quantitative PCR led to the selection of 69 strains as being reduced in relative abundance during nodulation. Plant assays conducted with individual strains confirmed that 3 were defective in nodulation (Nod-) and that 10 were Nod+but defective in nitrogen fixation (Fix-); in each case, the symbiosis deficiency could be attributed to the transposon insertion carried by that strain. Although the remaining 56 strains were Fix+, 33 of them showed significantly reduced competitiveness during nodulation. Among the mutants we identified are known genes that are diverse in predicted function as well as some genes of unknown function, which demonstrates the validity of this screening procedure for functional genomics in rhizobia.
KW - Competitiveness
KW - Mesorhizobium loti
KW - Root nodule
KW - Signature-tagged mutagenesis
KW - Symbiosis
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U2 - 10.1264/jsme2.ME10213
DO - 10.1264/jsme2.ME10213
M3 - Article
C2 - 21502733
AN - SCOPUS:79958199272
VL - 26
SP - 165
EP - 171
JO - Microbes and Environments
JF - Microbes and Environments
SN - 1342-6311
IS - 2
ER -