Identification of genes regulated by the antitermination factor nasT during denitrification in Bradyrhizobium diazoefficiens

Cristina Sanchez Gomez, Arthur Fernandes Siqueira, Hisayuki Mitsui, Kiwamu Minamisawa

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

The soybean symbiont Bradyrhizobium diazoefficiens grows anaerobically in the presence of nitrate using the denitrification pathway, which involves the nap, nir, nor, and nos genes. We previously showed that NasT acts as a transcription antitermination regulator for nap and nos gene expression. In the present study, we investigated the targets of NasT in B. diazoefficiens during denitrifying growth by performing transcription profiling with RNA-seq and quantitative reverse-transcription PCR. Most of the genes with altered expression in the absence of NasT were related to nitrogen metabolism, specifically several systems for branched-chain amino acid transport. The present results suggest that the reduced expression of genes involved in nitrogen acquisition leads to the induction of alternative sets of genes with similar functions. The δnasT mutant of B. diazoefficiens grew better than the wild type under denitrifying conditions. However, this enhanced growth was completely abolished by an additional loss of the narK or bjgb genes, which encode cytoplasmic systems for nitrite and nitric oxide detoxification, respectively. Since the expression of narK and bjgb was increased in the δnasT mutant, the growth of the δnasT mutant may be promoted by increased detoxification activity.

Original languageEnglish
Pages (from-to)260-267
Number of pages8
JournalMicrobes and environments
Volume34
Issue number3
DOIs
Publication statusPublished - 2019 Jan 1

Keywords

  • Bradyrhizobium
  • Denitrification
  • NasT
  • RNA-seq
  • Transcriptional regulation

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Soil Science
  • Plant Science

Fingerprint Dive into the research topics of 'Identification of genes regulated by the antitermination factor nasT during denitrification in Bradyrhizobium diazoefficiens'. Together they form a unique fingerprint.

  • Cite this