Pseudomonas syringae manipulates systemic plant defenses against pathogens and herbivores. (2005)
Cui, J., Bahrami, A. K, Pringle, E. G, Hernandez-Guzman, G., Bender, C. L, Pierce, N. E, ...
Many pathogens are virulent because they specifically interfere with host defense responses and therefore can proliferate. Here, we report that virulent strains of the bacterial phytopathogen...
Virulence of the phytopathogen Pseudomonas syringae pv. maculicola Is rpoN dependent. (2000)
Hendrickson, E. L, Guevera, P., Penaloza-Vazquez, A., Shao, J., Bender, C., Ausubel, F. M
We cloned the rpoN (ntrA and glnF) gene encoding ς54 from the phytopathogen Pseudomonas syringae pv. maculicola strain ES4326. The P. syringae ES4326 rpoN gene complemented Pseudomonas...
Analysis of Arabidopsis mutants deficient in flavonoid biosynthesis. (1995)
Shirley, B.W., Kubasek, W.L., Storz, G., Bruggemann, E., Koornneef, M., Ausubel, F.M., ...
Dickstein, R., Bisseling, T., Reinhold, V.N., Ausubel, F.M.
To help dissect the molecular basis of the Rhizobium-legume symbiosis, we used in vitro translation and Northern blot analysis of nodule RNA to examine alfalfa-specific genes (nodulins) expressed in...
Buikema, W.J., Szeto, W.W., Lemley, P.V., Orme-Johnson, W.H., Ausubel, F.M.
We have determined the complete nucleotide sequences of three functionally related nitrogen assimilation regulatory genes from Klebsiella pneumoniae and Rhizobium meliloti. These genes are:1) The...
Use of Arabidopsis thaliana defense-related mutants to dissect the plant response to pathogens.
Ausubel, F M, Katagiri, F, Mindrinos, M, Glazebrook, J
The plant defense response to microbial pathogens had been studied primarily by using biochemical and physiological techniques. Recently, several laboratories have developed a variety of pathosystems...
A genetic approach was used to assess the extent to which a particular plant defense response, phytoalexin biosynthesis, contributes to Arabidopsis thaliana resistance to Pseudomonas syringae...
copia-like retrotransposons are ubiquitous among plants.
Voytas, D F, Cummings, M P, Koniczny, A, Ausubel, F M, Rodermel, S R
Transposable genetic elements are assumed to be a feature of all eukaryotic genomes. Their identification, however, has largely been haphazard, limited principally to organisms subjected to molecular...
Michel, J L, Madoff, L C, Olson, K, Kling, D E, Kasper, D L, Ausubel, F M
Group B Streptococcus (GBS) is the leading cause of neonatal sepsis and meningitis in the United States. The surface-associated C protein alpha antigen of GBS is thought to have a role in both...
Keith, B, Dong, X N, Ausubel, F M, Fink, G R
We have isolated cDNAs from two distinct genes encoding 3-deoxy-D-arabino-heptulosonate 7-phosphate (DAHP) synthase (EC 4.1.2.15) in Arabidopsis thaliana. Predicted protein sequences from both genes,...
Genomic subtraction for cloning DNA corresponding to deletion mutations.
We have developed a technique, called genomic subtraction, for isolating the DNA that is absent in deletion mutants. The method removes from wild-type DNA the sequences that are present in both the...
To identify plant defense responses that limit pathogen attack, Arabidopsis eds mutants that exhibit enhanced disease susceptibility to the virulent bacterial pathogen Pseudomonas syringae pv...
Dong, X, Mindrinos, M, Davis, K R, Ausubel, F M
We developed a model system to study the signal transduction pathways leading to the activation of Arabidopsis thaliana genes involved in the defense against pathogen attack. Here we describe the...
Melan, M A, Dong, X, Endara, M E, Davis, K R, Ausubel, F M, Peterman, T K
We isolated and characterized a 2.8-kb, full-length, Arabidopsis thaliana cDNA clone encoding a lipoxygenase. DNA sequence analysis showed that the deduced amino acid sequence of the Arabidopsis...
The Arabidopsis disease resistance gene RPS2 is involved in recognition of bacterial pathogens carrying the avirulence gene avrRpt2, and the RPM1 resistance gene is involved in recognition of...
Huala, E, Stigter, J, Ausubel, F M
Sigma 54-dependent transcriptional activators such as Escherichia coli NtrC, Rhizobium meliloti NifA, and Rhizobium leguminosarum DctD share similar central and carboxy-terminal domains but differ in...
Huala, E, Moon, A L, Ausubel, F M
The Rhizobium meliloti NifA protein is an oxygen-sensitive transcriptional regulator of nitrogen fixation genes. Regulation of NifA activity by oxygen occurs at the transcriptional level through...
Rhizobium meliloti nodD genes mediate host-specific activation of nodABC.
Honma, M A, Asomaning, M, Ausubel, F M
To differentiate among the roles of the three nodD genes of Rhizobium meliloti 1021, we studied the activation of a nodC-lacZ fusion by each of the three nodD genes in response to root exudates from...
De Bruijn, F J, Rossbach, S, Schneider, M, Ratet, P, Messmer, S, Szeto, W W, ...
We have cloned and characterized three distinct Rhizobium meliloti loci involved in glutamine biosynthesis (glnA, glnII, and glnT). The glnA locus shares DNA homology with the glnA gene of Klebsiella...
Albright, L M, Ronson, C W, Nixon, B T, Ausubel, F M
The ntrA gene of Rhizobium meliloti has recently been identified and shown to be required for a diverse set of metabolic functions (C. W. Ronson, B. T. Nixon, L. M. Albright, and F. M. Ausubel, J....
The Rhizobium meliloti nifA product (NifA) shares extensive homology in its central region and at its C-terminal end with Rhizobium leguminosarum DctD and with NtrC from several species. All three...
Debellé, F, Maillet, F, Vasse, J, Rosenberg, C, De Billy, F, Truchet, G, ...
Transfer of an IncP plasmid carrying the Rhizobium meliloti nodFE, nodG, and nodH genes to Rhizobium trifolii enabled R. trifolii to nodulate alfalfa (Medicago sativa), the normal host of R....
Conservation of structure and location of Rhizobium meliloti and Klebsiella pneumoniae nifB genes.
Buikema, W J, Klingensmith, J A, Gibbons, S L, Ausubel, F M
Using transposon Tn5-mediated mutagenesis, an essential Rhizobium meliloti nitrogen fixation (nif) gene was identified and located directly downstream of the regulatory gene nifA. Maxicell and DNA...
Genetic and structural analysis of the Rhizobium meliloti fixA, fixB, fixC, and fixX genes.
Earl, C D, Ronson, C W, Ausubel, F M
The fixA, fixB, fixC, and fixX genes of Rhizobium meliloti 1021 constitute an operon and are required for nitrogen fixation in alfalfa nodules. DNA homologous to the R. meliloti fixABC genes is...
Szeto, W W, Nixon, B T, Ronson, C W, Ausubel, F M
We show here that Rhizobium meliloti, the nitrogen-fixing endosymbiont of alfalfa (Medicago sativa), has a regulatory gene that is structurally homologous to previously characterized ntrC genes in...
Rhizobium meliloti ntrA (rpoN) gene is required for diverse metabolic functions.
Ronson, C W, Nixon, B T, Albright, L M, Ausubel, F M
We report the identification and cloning of an ntrA-like (glnF rpoN) gene of Rhizobium meliloti and show that the R. meliloti ntrA product (NtrA) is required for C4-dicarboxylate transport as well as...
Wilson, K J, Anjaiah, V, Nambiar, P T, Ausubel, F M
Random transposon Tn5 mutagenesis of Bradyrhizobium sp. (Arachis) strain NC92, a member of the cowpea cross-inoculation group, was carried out, and kanamycin-resistant transconjugants were tested for...
Paraquat-mediated selection for mutations in the manganese-superoxide dismutase gene sodA.
We report the unexpected result that Escherichia coli isolates containing a multicopy plasmid (pDT1.5) carrying the manganese-superoxide dismutase gene sodA were more sensitive than the wild type to...
Mutations affecting regulation of the Klebsiella pneumoniae nifH (nitrogenase reductase) promotor.
Starting with plasmid pSA30 which contains an intact nifHDKY operon, we selected mutants that no longer inhibited nitrogen fixation in Klebsiella pneumoniae. Three categories of mutants were found...
Hirsch, A M, Wilson, K J, Jones, J D, Bang, M, Walker, V V, Ausubel, F M
Regions of the Rhizobium meliloti symbiotic plasmid (20 to 40 kilobase pairs long) containing nodulation (nod) genes were transferred to Agrobacterium tumefaciens or Escherichia coli by conjugation....
Meade, H M, Long, S R, Ruvkun, G B, Brown, S E, Ausubel, F M
We have physically and genetically characterized 20 symbiotic and 20 auxotrophic mutants of Rhizobium meliloti, the nitrogen-fixing symbiont of alfalfa (Medicago sativa), isolated by transposon Tn5...
Ausubel, F M, Bird, S C, Durbin, K J, Janssen, K A, Margolskee, R F, Peskin, A P
Previous studies have implicated glutamine synthetase (L-glutamate:ammonia ligase [adenosine diphosphate for-ing], EC 6.6.1.2) as a major controlling element of the nitrogen fixation (nif) genes in...
Cyanobacterial ribonucleic acid polymerases recognize lambda promoters.
Miller, S S, Ausubel, F M, Bogorad, L
We compared the initiation specificities in vitro of deoxyribonucleic acid-dependent ribonucleic acid polymerases purified from two cyanobacteria, Fremyella diplosiphon and Anacystis nidulans, and...
Nitrogen fixation by Klebsiella pneumoniae is inhibited by certain multicopy hybrid nif plasmids.
Riedel, G E, Brown, S E, Ausubel, F M
In our studies of nif gene regulation, we have observed that certain hybrid nif plasmids drastically inhibit the expression of the chromosomal nif genes of Klebsiella pneumonia. Wild-type (Nif+) K....
Structural studies of alfalfa roots infected with nodulation mutants of Rhizobium meliloti.
Hirsch, A M, Long, S R, Bang, M, Haskins, N, Ausubel, F M
Alfalfa roots infected with four nodulation defective (Nod-) mutants of Rhizobium meliloti which were generated by transposon Tn5 mutagenesis were examined by light and electron microscopy. In one...
Use of cleaved amplified polymorphic sequences to distinguish strains of Staphylococcus epidermidis.
Calderwood, S B, Baker, M A, Carroll, P A, Michel, J L, Arbeit, R D, Ausubel, F M
We examined the utility of a PCR-based method termed cleaved amplified polymorphic sequences (CAPS) to type 35 well-characterized isolates of Staphylococcus epidermidis. The results were compared...
Cloned alpha and beta C-protein antigens of group B streptococci elicit protective immunity.
Michel, J L, Madoff, L C, Kling, D E, Kasper, D L, Ausubel, F M
Streptococcus agalactiae (group B streptococci [GBS]) is the leading cause of neonatal sepsis and meningitis in the United States. The surface-associated C proteins of GBS play a role in immunity,...
Rhizobium meliloti has three functional copies of the nodD symbiotic regulatory gene.
We have identified two Rhizobium meliloti genes (nodD2 and nodD3) that are highly homologous and closely linked to the regulatory gene nodD (nodD1). R. meliloti strains containing mutations in the...
Ronson, C W, Astwood, P M, Nixon, B T, Ausubel, F M
We have sequenced two genes dctB and dctD required for the activation of the C4-dicarboxylate transport structural gene dctA in free-living Rhizobium leguminosarum. The hydropathic profile of the...
Bloch, C A, Thorne, G M, Ausubel, F M
A defined deletion in the Escherichia coli K-12 sodA gene (encoding manganese-superoxide dismutase) linked to a nontransposable selectable marker was generated by transposon Tn5 insertion in...
Buikema, W J, Szeto, W W, Lemley, P V, Orme-Johnson, W H, Ausubel, F M
We have determined the complete nucleotide sequences of three functionally related nitrogen assimilation regulatory genes from Klebsiella pneumoniae and Rhizobium meliloti. These genes are: 1) The K....
The centromere region of Arabidopsis thaliana chromosome 1 contains telomere-similar sequences.
Richards, E J, Goodman, H M, Ausubel, F M
We describe the structure of an Arabidopsis thaliana genomic clone containing two classes of repetitive DNA elements derived from the centromere region of chromosome 1. One class is comprised of...
Olszewski, N E, Martin, F B, Ausubel, F M
We constructed a cosmid vector, pOCA18, designed for transferring plant genomic libraries from Agrobacterium tumefaciens to plants. Clones from a genomic library of Arabidopsis thaliana DNA in pOCA...
Interspecies homology of nitrogenase genes.
Cloned nitrogen fixation (nif) genes from Klebsiella pneumoniae hybridize to DNA from 19 out of 19 widely divergent nitrogen-fixing bacterial strains but do not hybridize to DNA from 10 different...
Transcriptional regulation of the Arabidopsis thaliana chalcone synthase gene.
We have cloned an Arabidopsis thaliana chalcone synthase (CHS) gene on the basis of cross-hybridization with a Petroselinum hortense CHS cDNA clone. The protein sequence deduced from the A. thaliana...
Nixon, B T, Ronson, C W, Ausubel, F M
We report that the ntrB and ntrC proteins of Bradyrhizobium sp. [Parasponia] strain RP501 share homology with other regulatory proteins. There is extensive conservation of C-terminal regions between...
Ow, D W, Sundaresan, V, Rothstein, D M, Brown, S E, Ausubel, F M
We have determined the nucleotide sequences of the Klebsiella pneumoniae nifL (regulation of N2 fixation genes) and the Escherichia coli glnA (glutamine synthetase) promoters. We compared these...
Sundaresan, V, Ow, D W, Ausubel, F M
We have studied the expression, in different Escherichia coli gln (ntr) mutants, of fusions (constructed in vitro) of the nifHDK (nitrogenase) promoters from Klebsiella pneumoniae and Rhizobium...
Cannon, F C, Riedel, G E, Ausubel, F M
We have cloned fragments of the Klebsiella pneumoniae genome that carry part of the his operon and part of the nitrogen fixation (nif) gene cluster on the amplifiable plasmid pMB9. One particular...
De Bruijn, F J, Stroke, I L, Marvel, D J, Ausubel, F M
Multicopy plasmids containing the hisDG region of Klebsiella pneumoniae were mutagenized with transposon Tn5. The resulting plasmids were examined for their ability to complement hisD and hisG...
Hirsch, A M, Bang, M, Ausubel, F M
Ineffective alfalfa nodules formed by Rhizobium meliloti nif::Tn5 mutants were examined by light and electron microscopy. R. meliloti nifH::Tn5 mutants formed nodules that were similar in structure...
P4 is a satellite phage of P2 and is dependent on phage P2 gene products for virion assembly and cell lysis. Previously, we showed that a virulent mutant of phage P4 (P4 vir1) could be used as a...
Molecular characterization of Tn5-induced symbiotic (Fix-) mutants of Rhizobium meliloti.
Zimmerman, J L, Szeto, W W, Ausubel, F M
To investigate the expression of specific symbiotic genes during the development of nitrogen-fixing root nodules, we conducted a systematic analysis of nodule-specific proteins and RNAs produced...
Voytas, D. F., Konieczny, A., Cummings, M. P., Ausubel, F. M.
The Ta1 elements are a low copy number, copia-like retrotransposable element family of Arabidopsis thaliana. Six Ta1 insertions comprise all of the Ta1 element copies found in three geographically...
A Superfamily of Arabidopsis Thaliana Retrotransposons
Konieczny, A., Voytas, D. F., Cummings, M. P., Ausubel, F. M.
We describe a superfamily of Arabidopsis thaliana retrotransposable elements that consists of at least ten related families designated Ta1-Ta10. The Ta1 family has been described previously. Two...
Hanfstingl, U., Berry, A., Kellogg, E. A., Costa-III., J. T., Rudiger, W., Ausubel, F. M.
We designate a region of the alcohol dehydrogenase locus (Adh) of the weedy crucifer, Arabidopsis thaliana, as ``hypervariable'' on the basis of a comparison of sequences from ecotypes Columbia and...
Isolation of Arabidopsis Mutants with Enhanced Disease Susceptibility by Direct Screening
Glazebrook, J., Rogers, E. E., Ausubel, F. M.
To discover which components of plant defense responses make significant contributions to limiting pathogen attack, we screened a mutagenized population of Arabidopsis thaliana for individuals that...
Glazebrook, J., Zook, M., Mert, F., Kagan, I., Rogers, E. E., Crute, I. R., ...
We are working to determine the role of the Arabidopsis phytoalexin, camalexin, in protecting the plant from pathogen attack by isolating phytoalexin-deficient (pad) mutants in the accession Columbia...
Volko, S M, Boller, T, Ausubel, F M
To identify plant defense components that are important in restricting the growth of virulent pathogens, we screened for Arabidopsis mutants in the accession Columbia (carrying the transgene...
Use of Arabidopsis thaliana defense-related mutants to dissect the plant response to pathogens.
Ausubel, F M, Katagiri, F, Mindrinos, M, Glazebrook, J
The plant defense response to microbial pathogens had been studied primarily by using biochemical and physiological techniques. Recently, several laboratories have developed a variety of pathosystems...
A genetic approach was used to assess the extent to which a particular plant defense response, phytoalexin biosynthesis, contributes to Arabidopsis thaliana resistance to Pseudomonas syringae...
copia-like retrotransposons are ubiquitous among plants.
Voytas, D F, Cummings, M P, Koniczny, A, Ausubel, F M, Rodermel, S R
Transposable genetic elements are assumed to be a feature of all eukaryotic genomes. Their identification, however, has largely been haphazard, limited principally to organisms subjected to molecular...
Michel, J L, Madoff, L C, Olson, K, Kling, D E, Kasper, D L, Ausubel, F M
Group B Streptococcus (GBS) is the leading cause of neonatal sepsis and meningitis in the United States. The surface-associated C protein alpha antigen of GBS is thought to have a role in both...
Keith, B, Dong, X N, Ausubel, F M, Fink, G R
We have isolated cDNAs from two distinct genes encoding 3-deoxy-D-arabino-heptulosonate 7-phosphate (DAHP) synthase (EC 4.1.2.15) in Arabidopsis thaliana. Predicted protein sequences from both genes,...
Genomic subtraction for cloning DNA corresponding to deletion mutations.
We have developed a technique, called genomic subtraction, for isolating the DNA that is absent in deletion mutants. The method removes from wild-type DNA the sequences that are present in both the...
To identify plant defense responses that limit pathogen attack, Arabidopsis eds mutants that exhibit enhanced disease susceptibility to the virulent bacterial pathogen Pseudomonas syringae pv...
Dong, X, Mindrinos, M, Davis, K R, Ausubel, F M
We developed a model system to study the signal transduction pathways leading to the activation of Arabidopsis thaliana genes involved in the defense against pathogen attack. Here we describe the...
Melan, M A, Dong, X, Endara, M E, Davis, K R, Ausubel, F M, Peterman, T K
We isolated and characterized a 2.8-kb, full-length, Arabidopsis thaliana cDNA clone encoding a lipoxygenase. DNA sequence analysis showed that the deduced amino acid sequence of the Arabidopsis...
The Arabidopsis disease resistance gene RPS2 is involved in recognition of bacterial pathogens carrying the avirulence gene avrRpt2, and the RPM1 resistance gene is involved in recognition of...
Huala, E, Stigter, J, Ausubel, F M
Sigma 54-dependent transcriptional activators such as Escherichia coli NtrC, Rhizobium meliloti NifA, and Rhizobium leguminosarum DctD share similar central and carboxy-terminal domains but differ in...
Huala, E, Moon, A L, Ausubel, F M
The Rhizobium meliloti NifA protein is an oxygen-sensitive transcriptional regulator of nitrogen fixation genes. Regulation of NifA activity by oxygen occurs at the transcriptional level through...
Rhizobium meliloti nodD genes mediate host-specific activation of nodABC.
Honma, M A, Asomaning, M, Ausubel, F M
To differentiate among the roles of the three nodD genes of Rhizobium meliloti 1021, we studied the activation of a nodC-lacZ fusion by each of the three nodD genes in response to root exudates from...
De Bruijn, F J, Rossbach, S, Schneider, M, Ratet, P, Messmer, S, Szeto, W W, ...
We have cloned and characterized three distinct Rhizobium meliloti loci involved in glutamine biosynthesis (glnA, glnII, and glnT). The glnA locus shares DNA homology with the glnA gene of Klebsiella...
Albright, L M, Ronson, C W, Nixon, B T, Ausubel, F M
The ntrA gene of Rhizobium meliloti has recently been identified and shown to be required for a diverse set of metabolic functions (C. W. Ronson, B. T. Nixon, L. M. Albright, and F. M. Ausubel, J....
The Rhizobium meliloti nifA product (NifA) shares extensive homology in its central region and at its C-terminal end with Rhizobium leguminosarum DctD and with NtrC from several species. All three...
Debellé, F, Maillet, F, Vasse, J, Rosenberg, C, De Billy, F, Truchet, G, ...
Transfer of an IncP plasmid carrying the Rhizobium meliloti nodFE, nodG, and nodH genes to Rhizobium trifolii enabled R. trifolii to nodulate alfalfa (Medicago sativa), the normal host of R....
Conservation of structure and location of Rhizobium meliloti and Klebsiella pneumoniae nifB genes.
Buikema, W J, Klingensmith, J A, Gibbons, S L, Ausubel, F M
Using transposon Tn5-mediated mutagenesis, an essential Rhizobium meliloti nitrogen fixation (nif) gene was identified and located directly downstream of the regulatory gene nifA. Maxicell and DNA...
Genetic and structural analysis of the Rhizobium meliloti fixA, fixB, fixC, and fixX genes.
Earl, C D, Ronson, C W, Ausubel, F M
The fixA, fixB, fixC, and fixX genes of Rhizobium meliloti 1021 constitute an operon and are required for nitrogen fixation in alfalfa nodules. DNA homologous to the R. meliloti fixABC genes is...
Szeto, W W, Nixon, B T, Ronson, C W, Ausubel, F M
We show here that Rhizobium meliloti, the nitrogen-fixing endosymbiont of alfalfa (Medicago sativa), has a regulatory gene that is structurally homologous to previously characterized ntrC genes in...
Rhizobium meliloti ntrA (rpoN) gene is required for diverse metabolic functions.
Ronson, C W, Nixon, B T, Albright, L M, Ausubel, F M
We report the identification and cloning of an ntrA-like (glnF rpoN) gene of Rhizobium meliloti and show that the R. meliloti ntrA product (NtrA) is required for C4-dicarboxylate transport as well as...
Wilson, K J, Anjaiah, V, Nambiar, P T, Ausubel, F M
Random transposon Tn5 mutagenesis of Bradyrhizobium sp. (Arachis) strain NC92, a member of the cowpea cross-inoculation group, was carried out, and kanamycin-resistant transconjugants were tested for...
Paraquat-mediated selection for mutations in the manganese-superoxide dismutase gene sodA.
We report the unexpected result that Escherichia coli isolates containing a multicopy plasmid (pDT1.5) carrying the manganese-superoxide dismutase gene sodA were more sensitive than the wild type to...
Mutations affecting regulation of the Klebsiella pneumoniae nifH (nitrogenase reductase) promotor.
Starting with plasmid pSA30 which contains an intact nifHDKY operon, we selected mutants that no longer inhibited nitrogen fixation in Klebsiella pneumoniae. Three categories of mutants were found...
Hirsch, A M, Wilson, K J, Jones, J D, Bang, M, Walker, V V, Ausubel, F M
Regions of the Rhizobium meliloti symbiotic plasmid (20 to 40 kilobase pairs long) containing nodulation (nod) genes were transferred to Agrobacterium tumefaciens or Escherichia coli by conjugation....
Meade, H M, Long, S R, Ruvkun, G B, Brown, S E, Ausubel, F M
We have physically and genetically characterized 20 symbiotic and 20 auxotrophic mutants of Rhizobium meliloti, the nitrogen-fixing symbiont of alfalfa (Medicago sativa), isolated by transposon Tn5...
Ausubel, F M, Bird, S C, Durbin, K J, Janssen, K A, Margolskee, R F, Peskin, A P
Previous studies have implicated glutamine synthetase (L-glutamate:ammonia ligase [adenosine diphosphate for-ing], EC 6.6.1.2) as a major controlling element of the nitrogen fixation (nif) genes in...
Cyanobacterial ribonucleic acid polymerases recognize lambda promoters.
Miller, S S, Ausubel, F M, Bogorad, L
We compared the initiation specificities in vitro of deoxyribonucleic acid-dependent ribonucleic acid polymerases purified from two cyanobacteria, Fremyella diplosiphon and Anacystis nidulans, and...
Nitrogen fixation by Klebsiella pneumoniae is inhibited by certain multicopy hybrid nif plasmids.
Riedel, G E, Brown, S E, Ausubel, F M
In our studies of nif gene regulation, we have observed that certain hybrid nif plasmids drastically inhibit the expression of the chromosomal nif genes of Klebsiella pneumonia. Wild-type (Nif+) K....
Hirsch, A M, Bang, M, Ausubel, F M
Ineffective alfalfa nodules formed by Rhizobium meliloti nif::Tn5 mutants were examined by light and electron microscopy. R. meliloti nifH::Tn5 mutants formed nodules that were similar in structure...
P4 is a satellite phage of P2 and is dependent on phage P2 gene products for virion assembly and cell lysis. Previously, we showed that a virulent mutant of phage P4 (P4 vir1) could be used as a...
Molecular characterization of Tn5-induced symbiotic (Fix-) mutants of Rhizobium meliloti.
Zimmerman, J L, Szeto, W W, Ausubel, F M
To investigate the expression of specific symbiotic genes during the development of nitrogen-fixing root nodules, we conducted a systematic analysis of nodule-specific proteins and RNAs produced...
Structural studies of alfalfa roots infected with nodulation mutants of Rhizobium meliloti.
Hirsch, A M, Long, S R, Bang, M, Haskins, N, Ausubel, F M
Alfalfa roots infected with four nodulation defective (Nod-) mutants of Rhizobium meliloti which were generated by transposon Tn5 mutagenesis were examined by light and electron microscopy. In one...
Use of cleaved amplified polymorphic sequences to distinguish strains of Staphylococcus epidermidis.
Calderwood, S B, Baker, M A, Carroll, P A, Michel, J L, Arbeit, R D, Ausubel, F M
We examined the utility of a PCR-based method termed cleaved amplified polymorphic sequences (CAPS) to type 35 well-characterized isolates of Staphylococcus epidermidis. The results were compared...
Cloned alpha and beta C-protein antigens of group B streptococci elicit protective immunity.
Michel, J L, Madoff, L C, Kling, D E, Kasper, D L, Ausubel, F M
Streptococcus agalactiae (group B streptococci [GBS]) is the leading cause of neonatal sepsis and meningitis in the United States. The surface-associated C proteins of GBS play a role in immunity,...
Rhizobium meliloti has three functional copies of the nodD symbiotic regulatory gene.
We have identified two Rhizobium meliloti genes (nodD2 and nodD3) that are highly homologous and closely linked to the regulatory gene nodD (nodD1). R. meliloti strains containing mutations in the...
Ronson, C W, Astwood, P M, Nixon, B T, Ausubel, F M
We have sequenced two genes dctB and dctD required for the activation of the C4-dicarboxylate transport structural gene dctA in free-living Rhizobium leguminosarum. The hydropathic profile of the...
Bloch, C A, Thorne, G M, Ausubel, F M
A defined deletion in the Escherichia coli K-12 sodA gene (encoding manganese-superoxide dismutase) linked to a nontransposable selectable marker was generated by transposon Tn5 insertion in...
Buikema, W J, Szeto, W W, Lemley, P V, Orme-Johnson, W H, Ausubel, F M
We have determined the complete nucleotide sequences of three functionally related nitrogen assimilation regulatory genes from Klebsiella pneumoniae and Rhizobium meliloti. These genes are: 1) The K....
The centromere region of Arabidopsis thaliana chromosome 1 contains telomere-similar sequences.
Richards, E J, Goodman, H M, Ausubel, F M
We describe the structure of an Arabidopsis thaliana genomic clone containing two classes of repetitive DNA elements derived from the centromere region of chromosome 1. One class is comprised of...
Olszewski, N E, Martin, F B, Ausubel, F M
We constructed a cosmid vector, pOCA18, designed for transferring plant genomic libraries from Agrobacterium tumefaciens to plants. Clones from a genomic library of Arabidopsis thaliana DNA in pOCA...
Interspecies homology of nitrogenase genes.
Cloned nitrogen fixation (nif) genes from Klebsiella pneumoniae hybridize to DNA from 19 out of 19 widely divergent nitrogen-fixing bacterial strains but do not hybridize to DNA from 10 different...
Transcriptional regulation of the Arabidopsis thaliana chalcone synthase gene.
We have cloned an Arabidopsis thaliana chalcone synthase (CHS) gene on the basis of cross-hybridization with a Petroselinum hortense CHS cDNA clone. The protein sequence deduced from the A. thaliana...
Nixon, B T, Ronson, C W, Ausubel, F M
We report that the ntrB and ntrC proteins of Bradyrhizobium sp. [Parasponia] strain RP501 share homology with other regulatory proteins. There is extensive conservation of C-terminal regions between...
Ow, D W, Sundaresan, V, Rothstein, D M, Brown, S E, Ausubel, F M
We have determined the nucleotide sequences of the Klebsiella pneumoniae nifL (regulation of N2 fixation genes) and the Escherichia coli glnA (glutamine synthetase) promoters. We compared these...
Sundaresan, V, Ow, D W, Ausubel, F M
We have studied the expression, in different Escherichia coli gln (ntr) mutants, of fusions (constructed in vitro) of the nifHDK (nitrogenase) promoters from Klebsiella pneumoniae and Rhizobium...
Cannon, F C, Riedel, G E, Ausubel, F M
We have cloned fragments of the Klebsiella pneumoniae genome that carry part of the his operon and part of the nitrogen fixation (nif) gene cluster on the amplifiable plasmid pMB9. One particular...
De Bruijn, F J, Stroke, I L, Marvel, D J, Ausubel, F M
Multicopy plasmids containing the hisDG region of Klebsiella pneumoniae were mutagenized with transposon Tn5. The resulting plasmids were examined for their ability to complement hisD and hisG...
Voytas, D. F., Konieczny, A., Cummings, M. P., Ausubel, F. M.
The Ta1 elements are a low copy number, copia-like retrotransposable element family of Arabidopsis thaliana. Six Ta1 insertions comprise all of the Ta1 element copies found in three geographically...
A Superfamily of Arabidopsis Thaliana Retrotransposons
Konieczny, A., Voytas, D. F., Cummings, M. P., Ausubel, F. M.
We describe a superfamily of Arabidopsis thaliana retrotransposable elements that consists of at least ten related families designated Ta1-Ta10. The Ta1 family has been described previously. Two...
Hanfstingl, U., Berry, A., Kellogg, E. A., Costa-III., J. T., Rudiger, W., Ausubel, F. M.
We designate a region of the alcohol dehydrogenase locus (Adh) of the weedy crucifer, Arabidopsis thaliana, as ``hypervariable'' on the basis of a comparison of sequences from ecotypes Columbia and...
Isolation of Arabidopsis Mutants with Enhanced Disease Susceptibility by Direct Screening
Glazebrook, J., Rogers, E. E., Ausubel, F. M.
To discover which components of plant defense responses make significant contributions to limiting pathogen attack, we screened a mutagenized population of Arabidopsis thaliana for individuals that...
Glazebrook, J., Zook, M., Mert, F., Kagan, I., Rogers, E. E., Crute, I. R., ...
We are working to determine the role of the Arabidopsis phytoalexin, camalexin, in protecting the plant from pathogen attack by isolating phytoalexin-deficient (pad) mutants in the accession Columbia...
Volko, S M, Boller, T, Ausubel, F M
To identify plant defense components that are important in restricting the growth of virulent pathogens, we screened for Arabidopsis mutants in the accession Columbia (carrying the transgene...