Transcriptomic Response of the Diazotrophic Bacteria Gluconacetobacter diazotrophicus Strain PAL5 to Iron Limitation and Characterization of the fur Regulatory Network

• Published in: International journal of molecular sciences Vol. 23; no. 15; p. 8533
• Main Authors: Soares, Cleiton de Paula, Trada-Sfeir, Michelle Zibetti, Terra, Leonardo Araújo, Ferreira, Jéssica de Paula, Dos-Santos, Carlos Magno, Oliveira, Izamara Gesiele Bezerra de, Araújo, Jean Luiz Simões, Meneses, Carlos Henrique Salvino Gadelha, de Souza, Emanuel Maltempi, Baldani, José Ivo, Vidal, Marcia Soares
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.08.2022; MDPI
• Subjects: Bacteria; Biofilms; Biosynthesis; Cell division; Computer applications; Cytochrome; Endophytes; endophytic bacteria; Flagella; Fur protein; fur regulon; Gene expression; Genes; Genomes; Gluconacetobacter diazotrophicus; Homeostasis; Iron; iron homeostasis; Kinases; Metabolic pathways; Metabolism; Microorganisms; mRNA-Seq; Mutagenesis; plant growth-promoting bacteria; Proteins; RNA polymerase; Software; Sugarcane; Transcriptomics
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms23158533

Gluconacetobacter diazotrophicus has been the focus of several studies aiming to understand the mechanisms behind this endophytic diazotrophic bacterium. The present study is the first global analysis of the early transcriptional response of exponentially growing G. diazotrophicus to iron, an essential cofactor for many enzymes involved in various metabolic pathways. RNA-seq, targeted gene mutagenesis and computational motif discovery tools were used to define the G. diazotrophicusfur regulon. The data analysis showed that genes encoding functions related to iron homeostasis were significantly upregulated in response to iron limitations. Certain genes involved in secondary metabolism were overexpressed under iron-limited conditions. In contrast, it was observed that the expression of genes involved in Fe-S cluster biosynthesis, flagellar biosynthesis and type IV secretion systems were downregulated in an iron-depleted culture medium. Our results support a model that controls transcription in G. diazotrophicus by fur function. The G. diazotrophicusfur protein was able to complement an E. colifur mutant. These results provide new insights into the effects of iron on the metabolism of G. diazotrophicus, as well as demonstrate the essentiality of this micronutrient for the main characteristics of plant growth promotion by G. diazotrophicus.