Fis regulates the competitiveness of Pseudomonas putida on barley roots by inducing biofilm formation.
An important link between the environment and the physiological state of bacteria is the regulation of the transcription of a large number of genes by global transcription factors. One of the global regulators, Fis (factor for inversion stimulation), is well studied in Escherichia coli, but the role of this protein in pseudomonads has only been examined briefly. According to studies in Enterobacteriaceae, Fis regulates positively the flagellar movement of bacteria. In pseudomonads, flagellar movement is an important trait for the colonization of plant roots. Therefore we were interested in the role of the Fis protein in Pseudomonas putida, especially the possible regulation of the colonization of plant roots. We observed that Fis reduced the migration of P. putida onto the apices of barley roots and thereby the competitiveness of bacteria on the roots. Moreover, we observed that overexpression of Fis drastically reduced swimming motility and facilitated P. putida biofilm formation, which could be the reason for the decreased migration of bacteria onto the root apices. It is possible that the elevated expression of Fis is important in the adaptation of P. putida during colonization of plant roots by promoting biofilm formation when the migration of bacteria is no longer favoured.
Department of Genetics, Institute of Molecular and Cell Biology, Tartu University and Estonian Biocentre, Riia 23, 51010 Tartu, Estonia.
Julia
J
Jakovleva
Department of Genetics, Institute of Molecular and Cell Biology, Tartu University and Estonian Biocentre, Riia 23, 51010 Tartu, Estonia.
Annika
A
Teppo
Department of Genetics, Institute of Molecular and Cell Biology, Tartu University and Estonian Biocentre, Riia 23, 51010 Tartu, Estonia.
Anna
A
Velts
Department of Genetics, Institute of Molecular and Cell Biology, Tartu University and Estonian Biocentre, Riia 23, 51010 Tartu, Estonia.
Signe
S
Saumaa
Department of Genetics, Institute of Molecular and Cell Biology, Tartu University and Estonian Biocentre, Riia 23, 51010 Tartu, Estonia.
Hanna
H
Moor
Department of Genetics, Institute of Molecular and Cell Biology, Tartu University and Estonian Biocentre, Riia 23, 51010 Tartu, Estonia.
Maia
M
Kivisaar
Department of Genetics, Institute of Molecular and Cell Biology, Tartu University and Estonian Biocentre, Riia 23, 51010 Tartu, Estonia.
Riho
R
Teras
D018441:Biofilms / Q000254:growth & development*; D004755:Enterobacteriaceae; D004926:Escherichia coli; D035021:Factor For Inversion Stimulation Protein / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D001467:Hordeum / Q000382:microbiology*; D008124:Locomotion; D018517:Plant Roots / Q000382:microbiology*; D016958:Pseudomonas putida / Q000254:growth & development*; D014774:Virulence
D035021:Factor For Inversion Stimulation Protein