The Pseudomonas fluorescens transcription activator AdnA is required for adhesion and motility The GenBank accession number for the sequence reported in this paper is AF312695.

Abstract

The locations of two mutations that prevent adhesion of Pseudomonas fluorescens Pf0-1 to sand columns and seeds (adn, adhesion) were identified. Both lie in a single gene showing homology to the NtrC/NifA family of transcription activators. The predicted 55 kDa protein encoded by adnA is most closely related to activators involved in expression of flagellar proteins, consistent with the lack of flagella in adnA strains. Constitutive adnA expression restored motility and adhesion to an adnA strain, demonstrating that the observed phenotypes are due to lack of AdnA and not a consequence of other mutations or polar effects of mutations in adnA on other genes.

Use of In Vivo Expression Technology To Identify Genes Important in Growth and Survival of Pseudomonas fluorescens Pf0-1 in Soil: Discovery of Expressed Sequences with Novel Genetic Organization

“…Selection for adherence defects led to the discovery of AdnA, a regulator affecting flagellum production, motility, attachment to sand and seeds (8,9), and biofilm formation (5). A mutation in adnA reduced the ability of Pf0-1 to spread and persist in soil (21).…”

Genetic Analysis of the AdnA Regulon in Pseudomonas fluorescens : Nonessential Role of Flagella in Adhesion to Sand and Biofilm Formation

“…Swim agar plates (MMO and 0.3% agar) were inoculated with bacteria from colonies grown overnight on LB agar using a sterile toothpick. After incubation overnight at 30°C, the growth away from the inoculation point was compared to that of the parent strain (6).…”

“…We disrupted adnA by inserting an omega cassette conferring streptomycin and spectinomycin resistance 500 bp from the translational start of adnA. The omega cassette was excised from pHRP315 (28) after DraI digestion and cloned into the PmlI site in the adnAcontaining plasmid pPF1B (6), giving rise to pJS6Dra. pJS6Dra, digested with SacI, yielded a 5-kb fragment containing 1.1 kb upstream of adnA, the first 500 bp of adnA, the 2-kb streptomycin resistance cassette, and 1.3 kb including the 3Ј end of adnA.…”

“…In addition, AdnA was shown to be required for biofilm formation and has 83% identity to FleQ in P. aeruginosa (6). Field studies showed that loss of adnA reduced the ability of P. fluorescens to spread and persist in soil (21).…”

“…Field studies showed that loss of adnA reduced the ability of P. fluorescens to spread and persist in soil (21). From their structure, AdnA and FleQ transcription factors appear to be members of the NtrC/NifA family of activators (6). In these systems, under the right environmental conditions, a sensor kinase phosphorylates an aspartate residue in the regulator protein that acts upon 54 -dependent promoters.…”