Exploring genetic diversity and signatures of horizontal gene transfer in nodule bacteria associated with lotus japonicus in natural environments

Masaru Bamba, Seishiro Aoki, Tadashi Kajita, Hiroaki Setoguchi, Yasuyuki Watano, Shusei Sato, Takashi Tsuchimatsu

研究成果: Article査読

6 被引用数 (Scopus)

抄録

To investigate the genetic diversity and understand the process of horizontal gene transfer (HGT) in nodule bacteria associated with Lotus japonicus, we analyzed sequences of three housekeeping and five symbiotic genes using samples from a geographically wide range in Japan. A phylogenetic analysis of the housekeeping genes indicated that L. japonicus in natural environments was associated with diverse lineages of Mesorhizobium spp., whereas the sequences of symbiotic genes were highly similar between strains, resulting in remarkably low nucleotide diversity at both synonymous and nonsynonymous sites. Guanine-cytosine content values were lower in symbiotic genes, and relative frequencies of recombination between symbiotic genes were also lower than those between housekeeping genes. An analysis of molecular variance showed significant genetic differentiation among populations in both symbiotic and housekeeping genes. These results confirm that the Mesorhizobium genes required for symbiosis with L. japonicus behave as a genomic island (i.e., a symbiosis island) and suggest that this island has spread into diverse genomic backgrounds of Mesorhizobium via HGT events in natural environments. Furthermore, our data compilation revealed that the genetic diversity of symbiotic genes in L. japonicus-associated symbionts was among the lowest compared with reports of other species, which may be related to the recent population expansion proposed in Japanese populations of L. japonicus.

本文言語English
ページ(範囲)1110-1120
ページ数11
ジャーナルMolecular Plant-Microbe Interactions
32
9
DOI
出版ステータスPublished - 2019

ASJC Scopus subject areas

  • 生理学
  • 農業および作物学

フィンガープリント

「Exploring genetic diversity and signatures of horizontal gene transfer in nodule bacteria associated with lotus japonicus in natural environments」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。

引用スタイル