Identification of virulence associated loci in the emerging broad host range plant pathogen Pseudomonas fuscovaginae.
BACKGROUND
Pseudomonas fuscovaginae (Pfv) is an emerging plant pathogen of rice and also of other gramineae plants. It causes sheath brown rot disease in rice with symptoms that are characterized by brown lesions on the flag leaf sheath, grain discoloration and sterility. It was first isolated as a high altitude pathogen in Japan and has since been reported in several countries throughout the world. Pfv is a broad host range pathogen and very little is known about its virulence mechanisms.


RESULTS
An in planta screen of 1000 random independent Tn5 genomic mutants resulted in the isolation of nine mutants which showed altered virulence. Some of these isolates are mutated for functions which are known to be virulence associated factors in other phytopathogenic bacteria (eg. pil gene, phytotoxins and T6SS) and others might represent novel virulence loci.


CONCLUSIONS
Being an emerging pathogen worldwide, the broad host range pathogen Pfv has not yet been studied for its virulence functions. The roles of the nine loci identified in the in planta screen are discussed in relation to pathogenicity of Pfv. In summary, this article reports a first study on the virulence of this pathogen involving in planta screening studies and suggests the presence of several virulence features with known and novel functions in the Pseudomonas group of bacteria.
International Centre for Genetic Engineering and Biotechnology, Trieste, Italy. patel@icgeb.org.
Hitendra Kumar
HK
Patel
International Centre for Genetic Engineering and Biotechnology, Trieste, Italy. mattiuzzo.maura@libero.it.
Maura
M
Matiuzzo
International Centre for Genetic Engineering and Biotechnology, Trieste, Italy. bertani@icgeb.org.
Iris
I
Bertani
International Centre for Genetic Engineering and Biotechnology, Trieste, Italy. VincentdePaul.Bigirimana@ugent.be.
Vincent de Paul
Vde P
Bigirimana
Graham Centre for Agricultural Innovation, School of Agricultural and Wine Sciences, Charles Sturt University, Wagga Wagga, NSW, 2650, Australia. gash@csu.edu.au.
Gavin J
GJ
Ash
Department of Crop Protection, Laboratory of Phytopathology, Ghent University, Coupure, Links 653, 9000, Ghent, Belgium. monica.hofte@ugent.be.
Monica
M
Höfte
International Centre for Genetic Engineering and Biotechnology, Trieste, Italy. venturi@icgeb.org.
Vittorio
V
Venturi
D004251:DNA Transposable Elements; D055786:Gene Knockout Techniques; D007564:Japan; D016254:Mutagenesis, Insertional; D010935:Plant Diseases / Q000382:microbiology*; D006109:Poaceae / Q000382:microbiology*; D011549:Pseudomonas / Q000235:genetics* / Q000254:growth & development* / Q000472:pathogenicity; D014774:Virulence
D004251:DNA Transposable Elements