nodT, a positively-acting cultivar specificity determinant controlling nodulation of Trifolium subterraneum by Rhizobium leguminosarum biovar trifolii

1991 ◽  
Vol 16 (4) ◽  
pp. 515-526 ◽  
Author(s):  
Wendy R. Lewis-Henderson ◽  
Michael A. Djordjevic
Keyword(s):  
Rhizobium Leguminosarum ◽  
Trifolium Subterraneum ◽  
Cultivar Specificity ◽  
Rhizobium Leguminosarum Biovar Trifolii

Erratum to: Two novel chromosomal loci influence cultivar-specific nodulation failure in the interaction between strain ANU794 and subterranean clover cv. Woogenellup

2002 ◽  
Vol 29 (7) ◽  
pp. 907
Author(s):  
Louise F. Roddam ◽  
Wendy R. Lewis-Henderson ◽  
Michael A. Djordjevic
Keyword(s):  
Rhizobium Leguminosarum ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Gene Interaction ◽  
Nodule Formation ◽  
Synthesis Inhibitor ◽  
Reading Frame ◽  
Ribosomal Protein L9 ◽  
Microbe Interactions ◽  
Cultivar Specificity

The nodulation failure resulting from the interaction between Rhizobium leguminosarum biovar trifolii strain ANU794 and the Trifolium subterraneum cv. Woogenellup was examined by transposon mutagenesis to resolve whether multiple determinants were involved in cultivar-specificity. Three new transposon-induced mutants of ANU794 (W72, W78 and W710) with significantly enhanced nodulation ability on cv. Woogenellup were identified. The W72 and W78 mutations are chromosomally-located, whereas the W710 mutation isplasmid-located. The ethylene synthesis inhibitor, aminoethoxyvinylglycine, fails to enhance the nodulation ability of ANU794, ANU7943 (csn1::Tn5) and W78 on cv. Woogenellup, but enhances the nodulation ability of W72,W710 and ANU7941 (nodM::Tn5). DNA sequencing of the W78 locus reveals strong homology to an unknown Mycobacterium open reading frame, and to several bacterial non-haem chloroperoxidases. The previously identified csn1 locus showed homology to the 50S ribosomal protein, L9, with the Tn5 insertion being located in the 5′-untranslated region. The results suggest that cultivar-specificity is mediated by at least two independent mechanisms or determinants, and not by a simple gene-for-gene interaction. The role of ethylene in cultivar specificity is discussed. Cultivar-specific interactions may prove useful in identifying pathways involved in efficient nodule formation and plant-microbe interactions.

Two novel chromosomal loci influence cultivar-specific nodulation failure in the interaction between strain ANU794 and subterranean clover cv. Woogenellup

2002 ◽  
Vol 29 (4) ◽  
pp. 473 ◽  
Author(s):  
Louise F. Roddam ◽  
Wendy R. Lewis-Henderson ◽  
Michael A. Djordjevic
Keyword(s):  
Rhizobium Leguminosarum ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Gene Interaction ◽  
Nodule Formation ◽  
Synthesis Inhibitor ◽  
Reading Frame ◽  
Ribosomal Protein L9 ◽  
Microbe Interactions ◽  
Cultivar Specificity

The nodulation failure resulting from the interaction between Rhizobium leguminosarum biovar trifolii strain ANU794 and the Trifolium subterraneum cv. Woogenellup was examined by transposon mutagenesis to resolve whether multiple determinants were involved in cultivar-specificity. Three new transposon-induced mutants of ANU794 (W72, W78 and W710) with significantly enhanced nodulation ability on cv. Woogenellup were identified. The W72 and W78 mutations are chromosomally-located, whereas the W710 mutation isplasmid-located. The ethylene synthesis inhibitor, aminoethoxyvinylglycine, fails to enhance the nodulation ability of ANU794, ANU7943 (csn1::Tn5) and W78 on cv. Woogenellup, but enhances the nodulation ability of W72,W710 and ANU7941 (nodM::Tn5). DNA sequencing of the W78 locus reveals strong homology to an unknown Mycobacterium open reading frame, and to several bacterial non-haem chloroperoxidases. The previously identified csn1 locus showed homology to the 50S ribosomal protein, L9, with the Tn5 insertion being located in the 5′-untranslated region. The results suggest that cultivar-specificity is mediated by at least two independent mechanisms or determinants, and not by a simple gene-for-gene interaction. The role of ethylene in cultivar specificity is discussed. Cultivar-specific interactions may prove useful in identifying pathways involved in efficient nodule formation and plant-microbe interactions.

Slow rehydration improves the recovery of dried bacterial populations

1992 ◽  
Vol 38 (6) ◽  
pp. 520-525 ◽  
Author(s):  
J. W. Kosanke ◽  
R. M. Osburn ◽  
G. I. Shuppe ◽  
R. S. Smith
Keyword(s):  
Relative Humidity ◽  
Rhizobium Leguminosarum ◽  
Moisture Absorption ◽  
Rhizobium Meliloti ◽  
Bacterial Populations ◽  
Bulk Powder ◽  
Alfalfa Seed ◽  
Powder Samples ◽  
Cellular Stresses ◽  
Rhizobium Leguminosarum Biovar Trifolii

Slow rehydration of bacteria from dried inoculant formulations provided higher viable counts than did rapid rehydration. Estimates were higher when clay and peat powder formulations of Rhizobium meliloti, Rhizobium leguminosarum biovar trifolii, and Pseudomonas putida, with water activities between 0.280 and 0.650, were slowly rehydrated to water activities of approximately 0.992 before continuing the dilution plating sequence. Rhizobium meliloti populations averaged 6.8 × 108 cfu/g and 1328 cfu/alfalfa seed greater when slowly rehydrated from bulk powder and preinoculated seeds, respectively. Bulk powder samples were slowly rehydrated to 0.992 water activity by the gradual addition of diluent, followed by a 10-min period for moisture equilibration. Preinoculated seed samples were placed in an environmental chamber at 24 °C with relative humidity greater than 80% for 1 h to allow moisture absorption. "Upshock," osmotic cellular stresses that occur during rehydration, was reduced when dried microbial formulations were slowly rehydrated and equilibrated before becoming fully hydrated in the dilution plating sequence. These procedures may also be applicable when estimating total viable bacterial populations from dried soil or other dry formulations. Key words: rehydration procedure, microbial rehydration, desiccation, Rhizobium, Pseudomonas.

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