The Journal of Microbiology

, Volume 49, Issue 6, pp 935–941

Identification, origin, and evolution of leaf nodulating symbionts of Sericanthe (Rubiaceae)

  • Benny Lemaire
  • Elmar Robbrecht
  • Braam van Wyk
  • Sandra Van Oevelen
  • Brecht Verstraete
  • Els Prinsen
  • Erik Smets
  • Steven Dessein
Articles

DOI: 10.1007/s12275-011-1163-5

Cite this article as:
Lemaire, B., Robbrecht, E., van Wyk, B. et al. J Microbiol. (2011) 49: 935. doi:10.1007/s12275-011-1163-5

Abstract

Bacterial leaf symbiosis is an intimate association between bacteria and plants in which endosymbionts are housed within leaf nodules. This phenomenon has been reported in three genera of Rubiaceae (Pavetta, Psychotria, and Sericanthe), but the bacterial partner has only been identified in Psychotria and Pavetta. Here we report the identification of symbiotic bacteria in two leaf nodulating Sericanthe species. Using 16S rRNA data and common housekeeping genetic markers (recA and gyrB) we studied the phylogenetic relationships of bacterial endosymbionts in Rubiaceae. Endosymbionts of leaf nodulating Rubiaceae were found to be closely related and were placed as a monophyletic group within the genus Burkholderia (β-Proteobacteria). The phylogenetic analyses revealed a pattern of strict host specificity and placed the two investigated endosymbionts at two distinct positions in the topology of the tree, suggesting at least two different evolutionary origins. The degree of sequence divergence between the Sericanthe endosymbionts and their relatives was large enough to propose the Sericanthe endosymbionts as new species (‘Candidatus Burkholderia andongensis’ and ‘Candidatus Burkholderia petitii’). In a second part of this study, the pylogenetic relationships among nodulating and non-nodulating Sericanthe species were investigated using sequence data from six chloroplast regions (rps16, trnG, trnL-trnF, petD, petA-psbJ, and atpI-atpH). Overall, genetic variation among the plastid markers was insufficient to enable phylogenetic estimation. However, our results could not rule out the possibility that bacterial leaf symbiosis originated once in a common ancestor of the Sericanthe species.

Keywords

Burkholderiaendosymbiontsbacterial leaf nodulationSericantheRubiaceae

Supplementary material

12275_2011_1163_MOESM1_ESM.pdf (985 kb)
Supplementary material, approximately 985 KB.

Copyright information

© The Microbiological Society of Korea and Springer-Verlag Berlin Heidelberg  2011

Authors and Affiliations

  • Benny Lemaire
    • 1
  • Elmar Robbrecht
    • 2
  • Braam van Wyk
    • 3
  • Sandra Van Oevelen
    • 4
  • Brecht Verstraete
    • 1
  • Els Prinsen
    • 4
  • Erik Smets
    • 1
    • 5
    • 6
  • Steven Dessein
    • 2
  1. 1.Laboratory of Plant SystematicsK.U.LeuvenLeuvenBelgium
  2. 2.National Botanic Garden of BelgiumMeiseBelgium
  3. 3.H.G.W.J. Schweickerdt HerbariumUniversity of PretoriaPretoriaSouth Africa
  4. 4.Laboratory of Plant Biochemistry and PhysiologyUniversity of AntwerpAntwerpBelgium
  5. 5.Netherlands Centre for Biodiversity NaturalisLeidenthe Netherlands
  6. 6.National Herbarium of the NetherlandsLeiden UniversityLeidenthe Netherlands