Proline auxotrophy in Sinorhizobium meliloti results in a plant-specific symbiotic phenotype

George C. diCenzo; Maryam Zamani; Turlough M. Finan; Alison Cowie

doi:10.1099/mic.0.000182

Symbiotic phenotype of a membrane-bound glucose dehydrogenase mutant of Sinorhizobium meliloti

Plant and Soil ◽

10.1007/s11104-008-9694-1 ◽

2008 ◽

Vol 313 (1-2) ◽

pp. 217-225 ◽

Cited By ~ 9

Author(s):

Cecilia E. Bernardelli ◽

María F. Luna ◽

María L. Galar ◽

José L. Boiardi

Keyword(s):

Sinorhizobium Meliloti ◽

Glucose Dehydrogenase ◽

Symbiotic Phenotype ◽

Membrane Bound

Download Full-text

Creation and multi-omics characterization of a genomically hybrid strain in the nitrogen-fixing symbiotic bacteriumSinorhizobium meliloti

10.1101/296483 ◽

2018 ◽

Cited By ~ 3

Author(s):

Alice Checcucci ◽

George C. diCenzo ◽

Veronica Ghini ◽

Marco Bazzicalupo ◽

Anke Becker ◽

...

Keyword(s):

Precision Agriculture ◽

Sinorhizobium Meliloti ◽

Metabolic Flux ◽

Symbiotic Bacterium ◽

Biotechnological Applications ◽

Bacterial Strains ◽

Hybrid Strain ◽

Single Genome ◽

Symbiotic Phenotype ◽

Multiple Strains

AbstractMany bacteria, often associated with eukaryotic hosts and of relevance for biotechnological applications, harbour a multipartite genome composed by more than one replicon. Biotechnologically relevant phenotypes are often encoded by genes residing on the secondary replicons. A synthetic biology approach to developing enhanced strains for biotechnological purposes could therefore involve merging pieces or entire replicons from multiple strains into a single genome. Here we report the creation of a genomic hybrid strain in a model multipartite genome species, the plant-symbiotic bacteriumSinorhizobium meliloti. In particular, we moved the secondary replicon pSymA (accounting for nearly 20% of total genome content) from a donorS. melilotistrain to an acceptor strain. Thecis-hybrid strain was screened for a panel of complex phenotypes (carbon/nitrogen utilization phenotypes, intra- and extra-cellular metabolomes, symbiosis, and various microbiological tests). Additionally, metabolic network reconstruction and constraint-based modelling were employed forin silicoprediction of metabolic flux reorganization. Phenotypes of thecis-hybrid strain were in good agreement with those of both parental strains. Interestingly, the symbiotic phenotype showed a marked cultivar-specific improvement with thecis-hybrid strains compared to both parental strains. These results provide a proof-of-principle for the feasibility of genome-wide replicon-based remodelling of bacterial strains for improved biotechnological applications in precision agriculture.

Download Full-text

Auxotrophy Accounts for Nodulation Defect of Most Sinorhizobium meliloti Mutants in the Branched-Chain Amino Acid Biosynthesis Pathway

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-21-9-1232 ◽

2008 ◽

Vol 21 (9) ◽

pp. 1232-1241 ◽

Cited By ~ 15

Author(s):

Maria de las Nieves Peltzer ◽

Nicolas Roques ◽

Véréna Poinsot ◽

O. Mario Aguilar ◽

Jacques Batut ◽

...

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Sinorhizobium Meliloti ◽

Amino Acid Biosynthesis ◽

Nodule Formation ◽

Biosynthesis Pathway ◽

Acid Biosynthesis ◽

Branched Chain Amino Acid ◽

Symbiotic Phenotype ◽

Branched Chain

Some Sinorhizobium meliloti mutants in genes involved in isoleucine, valine, and leucine biosynthesis were previously described as being unable to induce nodule formation on host plants. Here, we present a reappraisal of the interconnection between the branched-chain amino acid biosynthesis pathway and the nodulation process in S. meliloti. We characterized the symbiotic phenotype of seven mutants that are auxotrophic for isoleucine, valine, or leucine in two closely related S. meliloti strains, 1021 and 2011. We showed that all mutants were similarly impaired for nodulation and infection of the Medicago sativa host plant. In most cases, the nodulation phenotype was fully restored by the addition of the missing amino acids to the plant growth medium. This strongly suggests that auxotrophy is the cause of the nodulation defect of these mutants. However, we confirmed previous findings that ilvC and ilvD2 mutants in the S. meliloti 1021 genetic background could not be restored to nodulation by supplementation with exogenous amino acids even though their Nod factor production appeared to be normal.

Download Full-text

Multilocus Sequence Typing as an Approach for Population Analysis of Medicago-Nodulating Rhizobia

Journal of Bacteriology ◽

10.1128/jb.00335-06 ◽

2006 ◽

Vol 188 (15) ◽

pp. 5570-5577 ◽

Cited By ~ 28

Author(s):

Peter van Berkum ◽

Patrick Elia ◽

Bertrand D. Eardly

Keyword(s):

Genetic Structure ◽

Multilocus Sequence Typing ◽

Sinorhizobium Meliloti ◽

Population Analysis ◽

Strong Relationship ◽

Bacterial Genomes ◽

Sinorhizobium Medicae ◽

Symbiotic Phenotype ◽

Sequence Types ◽

Chromosomal Loci

ABSTRACT Multilocus sequence typing (MLST), a sequence-based method to characterize bacterial genomes, was used to examine the genetic structure in a large collection of Medicago-nodulating rhizobial strains. This is the first study where MLST has been applied in conjunction with eBURST analysis to determine the population genetic structure of nonpathogenic bacteria recovered from the soil environment. Sequence variation was determined in 10 chromosomal loci of 231 strains that predominantly originated from southwest Asia. Genetic diversity for each locus ranged from 0.351 to 0.819, and the strains examined were allocated to 91 different allelic profiles or sequence types (STs). The genus Medicago is nodulated by at least two groups of rhizobia with divergent chromosomes that have been classified as Sinorhizobium meliloti and Sinorhizobium medicae. Evidence was obtained that the degree of genetic exchange among the chromosomes across these groups is limited. The symbiosis with Medicago polymorpha of nine strains placed in one of these groups, previously identified as S. medicae, ranged from ineffective to fully effective, indicating that there was no strong relationship between symbiotic phenotype and chromosomal genotype.

Download Full-text

Rhizobium törzsek túléloképessége különbözo vivoanyagokban

Agrokémia és Talajtan ◽

10.1556/agrokem.52.2003.3-4.11 ◽

2003 ◽

Vol 52 (3-4) ◽

pp. 395-408 ◽

Cited By ~ 2

Author(s):

László Ködöböcz ◽

Borbála Biró ◽

Ilona Dusha ◽

Zoltánné Izsáki ◽

Lajos Sáry ◽

...

Keyword(s):

Sinorhizobium Meliloti

A lucerna magoltására alkalmas két Sinorhizobium meliloti törzs túléloképességét ellenoriztük laboratóriumi körülmények között. Az oltás szempontjait figyelembe véve a baktériumtörzsek túléloképességét a magfelszínen, folyékony táptalajban, talajban és mezogazdasági hulladék felhasználásával készített komposztban ellenoriztük 1-6 hetes idotartamban. A kiindulási sejtszámhoz képest a törzsek túléloképességét (pusztulását és esetleges szaporodását) az általunk módosított, szelektív táplemezes kitenyésztéssel követtük nyomon antibiotikum marker segítségével. Megállapítást nyert, hogy a különféle lucernamagvak felszínén a Rhizobium törzsek túléloképességét a fajtatulajdonságok erosen befolyásolják. A fajták és az oltóanyagok közötti kompatibilitás-vizsgálatoknak tehát a mikrobiális oltóanyagok alkalmazásánál nagy jelentosége van. Talajokban a Rhizobiumok perzisztenciáját a talajok kötöttsége, alacsony pH-ja és a tápanyag-szegény körülmények is gátolhatják. Az alkalmazott törzsek vivoanyagának a nagy szerves- és tápanyagtartalmú komposztok a legmegfelelobbek. Az anaerob módon eloállított komposzt a vizsgált törzsek túléloképességéhez kedvezobb körülményeket biztosít. Ennek oka feltételezésünk szerint a biotikus tényezok kedvezobb alakulása, azaz az anaerob körülményekhez adaptálódott konkurens mikrobák kisebb fokú versenyképessége lehet. Feltételezéseinket a sterilizált komposztban kimutatott nagyobb mértéku túléloképesség támasztja alá. A megfelelo komposztok ilyen irányú felhasználásával kiváltható a tozegek alkalmazása, az oltóanyag-eloállítási technológia gazdaságosabbá teheto.

Download Full-text