Defensive bacteriome symbiont with a drastically reduced genome

Atsushi Nakabachi, Reiko Ueoka, Kenshiro Oshima, Roberta Teta, Alfonso Mangoni, Mihaela Gurgui, Neil J. Oldham, Gerhild Van Echten-Deckert, Keiko Okamura, Kohei Yamamoto, Hiromitsu Inoue, Moriya Ohkuma, Yuichi Hongoh, Shin Ya Miyagishima, Masahira Hattori, Jörn Piel, Takema Fukatsu

Research output: Contribution to journalArticle

125 Citations (Scopus)

Abstract

Diverse insect species harbor symbiotic bacteria, which play important roles such as provisioning nutrients and providing defense against natural enemies [1-6]. Whereas nutritional symbioses are often indispensable for both partners, defensive symbioses tend to be of a facultative nature [1-12]. The Asian citrus psyllid Diaphorina citri is a notorious agricultural pest that transmits Liberibacter spp. (Alphaproteobacteria), causing the devastating citrus greening disease or Huanglongbing [13, 14]. In a symbiotic organ called the bacteriome, D. citri harbors two distinct intracellular symbionts: a putative nutrition provider, Carsonella-DC (Gammaproteobacteria), and an unnamed betaproteobacterium with unknown function [15], for which we propose the name "Candidatus Profftella armatura." Here we report that Profftella is a defensive symbiont presumably of an obligate nature with an extremely streamlined genome. The genomes of Profftella and Carsonella-DC were drastically reduced to 464,857 bp and 174,014 bp, respectively, suggesting their ancient and mutually indispensible association with the host. Strikingly, 15% of the small Profftella genome encoded horizontally acquired genes for synthesizing a novel polyketide toxin. The toxin was extracted, pharmacologically and structurally characterized, and designated diaphorin. The presence of Profftella and its diaphorin-biosynthetic genes was perfectly conserved in the world's D. citri populations.

Original languageEnglish
Pages (from-to)1478-1484
Number of pages7
JournalCurrent Biology
Volume23
Issue number15
DOIs
Publication statusPublished - 2013 Aug 5
Externally publishedYes

    Fingerprint

ASJC Scopus subject areas

  • Agricultural and Biological Sciences(all)
  • Biochemistry, Genetics and Molecular Biology(all)

Cite this

Nakabachi, A., Ueoka, R., Oshima, K., Teta, R., Mangoni, A., Gurgui, M., Oldham, N. J., Van Echten-Deckert, G., Okamura, K., Yamamoto, K., Inoue, H., Ohkuma, M., Hongoh, Y., Miyagishima, S. Y., Hattori, M., Piel, J., & Fukatsu, T. (2013). Defensive bacteriome symbiont with a drastically reduced genome. Current Biology, 23(15), 1478-1484. https://doi.org/10.1016/j.cub.2013.06.027