Details

Autor(en) / Beteiligte

• Itoh, Hideomi
• Jang, Seonghan
• Takeshita, Kazutaka
• Ohbayashi, Tsubasa
• Ohnishi, Naomi
• Meng, Xian-Ying
• Mitani, Yasuo
• Kikuchi, Yoshitomo

Titel

Host–symbiont specificity determined by microbe–microbe competition in an insect gut

Ist Teil von

• Proceedings of the National Academy of Sciences - PNAS, 2019-11, Vol.116 (45), p.22673-22682

Ort / Verlag

United States: National Academy of Sciences

Erscheinungsjahr

2019

Link zum Volltext

Quelle

MEDLINE

Beschreibungen/Notizen

• Despite the omnipresence of specific host–symbiont associations with acquisition of the microbial symbiont from the environment, little is known about how the specificity of the interaction evolved and is maintained. The bean bug Riptortus pedestris acquires a specific bacterial symbiont of the genus Burkholderia from environmental soil and harbors it in midgut crypts. The genus Burkholderia consists of over 100 species, showing ecologically diverse lifestyles, and including serious human pathogens, plant pathogens, and nodule-forming plant mutualists, as well as insect mutualists. Through infection tests of 34 Burkholderia species and 18 taxonomically diverse bacterial species, we demonstrate here that nonsymbiotic Burkholderia and even its outgroup Pandoraea could stably colonize the gut symbiotic organ and provide beneficial effects to the bean bug when inoculated on aposymbiotic hosts. However, coinoculation revealed that the native symbiont always outcompeted the nonnative bacteria inside the gut symbiotic organ, explaining the predominance of the native Burkholderia symbiont in natural bean bug populations. Hence, the abilities for colonization and cooperation, usually thought of as specific traits of mutualists, are not unique to the native Burkholderia symbiont but, to the contrary, competitiveness inside the gut is a derived trait of the native symbiont lineage only and was thus critical in the evolution of the insect gut symbiont.