Evidence of horizontal gene transfer between obligate leaf nodule symbionts

  title={Evidence of horizontal gene transfer between obligate leaf nodule symbionts},
  author={Marta Pinto-Carb{\'o} and Simon Sieber and Steven Dessein and Thomas Wicker and Brecht Verstraete and Karl Gademann and Leo Eberl and Aur{\'e}lien Carlier},
  journal={The ISME Journal},
Bacteria of the genus Burkholderia establish an obligate symbiosis with plant species of the Rubiaceae and Primulaceae families. The bacteria, housed within the leaves, are transmitted hereditarily and have not yet been cultured. We have sequenced and compared the genomes of eight bacterial leaf nodule symbionts of the Rubiaceae plant family. All of the genomes exhibit features consistent with genome erosion. Genes potentially involved in the biosynthesis of kirkamide, an insecticidal C7N… 
Early steps in the evolution of vertical transmission revealed by a plant-bacterium symbiosis
A very recent acquisition of the vertical mode of transmission is proposed in this symbiosis which, together with a large effective populations size, explain the cultivability and remarkable lack of genome reductive evolution in O. dioscoreae.
Distinct within-host bacterial populations ensure function, colonization and transmission in leaf symbiosis
It is demonstrated that inoculation of apical buds with a bacterial suspension is sufficient to colonize newly-formed leaves and propagules, and to ensure transmission to the next plant generation, and argued that this separation of functional symbiont populations, coupled to tight control over bacterial infection and transmission, explain the evolutionary robustness of leaf symbiosis.
Adaptations and evolution of a heritable leaf nodule symbiosis between Dioscorea sansibarensis and Orrella dioscoreae
A recent establishment of a vertical mode of transmission is proposed in this symbiosis which, together with a large effective population size, explains the cultivability and apparent lack of genome reductive evolution in O. dioscoreae.
Horizontal Gene Transfer to a Defensive Symbiont with a Reduced Genome in a Multipartite Beetle Microbiome
The microbiome associated with the eggs of the beetle Lagria villosa is described, consisting of multiple bacterial symbionts related to Burkholderia gladioli, including a reduced-genome symbiont thought to be the exclusive producer of the defensive compound lagriamide.
Provisional chapter Bacterial Leaf Nodule Symbiosis in Flowering Plants
The current knowledge of the bacterial leaf nodule symbiosis in angiosperm is reviewed and evidence from genomic sequences showed the symbiotic bacteria may serve as a defense role in Primulaceae and Rubiaceae, and may increase stress tolerance in Dioscoreaceae.
Bacterial Leaf Nodule Symbiosis in Flowering Plants
Bacterial leaf nodule symbiosis within angiosperms is a less known phenomenon compared to the well-documented legume root-Rhizobium symbiosis and certainly deserved much more scientific attention.
Conserved Proteins of the RNA Interference System in the Arbuscular Mycorrhizal Fungus Rhizoglomus irregulare Provide New Insight into the Evolutionary History of Glomeromycota
It is indicated that a unique acquisition of class I ribonuclease III in AMF is due to a HGT event that occurred from cyanobacteria to Glomeromycota, at the latest before the divergence of the two Glomercycota orders Diversisporales and Glomerales.
Versatile and Dynamic Symbioses Between Insects and Burkholderia Bacteria.
Insect-Burkholderia symbionts present valuable model systems from which to derive insights into general principles governing symbiotic interactions because they are often experimentally and genetically tractable and span a large fraction of the diversity of functions, localizations, and transmission routes represented in insect symbioses.
Mode and Fidelity of Bacterial Symbiont Transmission and Its Impact on Symbiont Genome Evolution
This work supports the existence of mixed transmission modes in symbiotic associations and indicates they have distinct consequences for symbiont evolution.


The eroded genome of a Psychotria leaf symbiont: hypotheses about lifestyle and interactions with its plant host.
The genome of the symbiont of Psychotria kirkii is sequenced for the first time and suggests that leaf nodule symbiosis benefits the host by providing protection against herbivores or pathogens.
Bacterial Leaf Symbiosis in Angiosperms: Host Specificity without Co-Speciation
Phylogenetic reconstruction of bacterial leaf symbionts and closely related free-living bacteria indicates the occurrence of multiple horizontal transfers of bacteria from the environment to leaf nodulated plant species, which rejects the hypothesis of a long co-speciation process between the bacterial endosymbions and their host plants.
Genome Erosion in a Nitrogen-Fixing Vertically Transmitted Endosymbiotic Multicellular Cyanobacterium
This is the first finding of genome degradation in a plant symbiont and phenotypically complex cyanobacterium and one of only a few extracellular endosymbionts described showing signs of reductive genome evolution.
Massive Genomic Decay in Serratia symbiotica, a Recently Evolved Symbiont of Aphids
The S. symbiotica genome provides a rare opportunity to study genome evolution in a recently derived heritable symbiont and exhibits several of the hallmarks of genome evolution observed in more ancient symbionts, including elevated rates of evolution and reduction in genome size.
Genome Degeneration and Adaptation in a Nascent Stage of Symbiosis
Structural, functional, and evolutionary analyses indicate that SOPE has undergone extensive adaptation toward an insect-associated lifestyle in a very short time period, and analyses of the bacterial cell envelope and genes encoding secretion systems suggest that these structures and elements have become simplified in the transition to a mutualistic association.
Genome reduction and co-evolution between the primary and secondary bacterial symbionts of psyllids.
Although the Carsonella genomes are generally conserved in size, structure, and GC content and exhibit genome-wide signatures of purifying selection, it is found that gene loss has remained active since the divergence of the host species and had a particularly large impact on the amino acid biosynthesis pathways that define the symbiotic role of Cars onella.
Horizontal Transfer of Bacterial Symbionts: Heritability and Fitness Effects in a Novel Aphid Host
  • J. Russell, N. Moran
  • Biology, Environmental Science
    Applied and Environmental Microbiology
  • 2005
These findings reveal that negative fitness effects and low transmission efficiency can prevent the establishment of a new infection following horizontal transmission, but indicate that some symbionts can overcome these obstacles, accounting for their widespread distributions across aphids and related insects.
Horizontal Gene Acquisition of Liberibacter Plant Pathogens from a Bacteriome-Confined Endosymbiont of Their Psyllid Vector
It is reported that a putative amino acid transporter LysE of Profftella forms a highly supported clade with proteins of L. asiaticus, L. americanus, and L. solanacearum, suggesting the possible evolutionary importance of HGT between plant pathogens and their insect vector’s symbionts that are confined in the symbiotic organ and seemingly sequestered from external microbial populations.
Symbiotic ß-Proteobacteria beyond Legumes: Burkholderia in Rubiaceae
This soil bacteria, together with related nodulating and non-nodulating endophytes, is transferred to a newly defined and larger PBE group within the genus Burkholderia.
Bacteriophage flux in endosymbionts (Wolbachia): infection frequency, lateral transfer, and recombination rates.
It is shown through several phylogenetic approaches that bacteriophage WO underwent recent lateral transfers between Wolbachia bacteria that coinfect host cells in the dipteran Drosophila simulans and the hymenopteran Nasonia vitripennis, supporting a general mechanism for genetic exchange in endosymbionts.