Fow2, a Zn(II)2Cys6-type transcription regulator, controls plant infection of the vascular wilt fungus Fusarium oxysporum.
The filamentous fungus Fusarium oxysporum is a soil-borne parasite that causes vascular wilts in a wide variety of crops by directly penetrating roots and colonizing the vascular tissue. In previous work, we generated the non-pathogenic mutant B137 of the melon wilt pathogen F. oxysporum f. sp. melonis by using restriction enzyme-mediated integration (REMI) mutagenesis. Molecular characterization of B137 revealed that this mutant has a single-copy plasmid insertion in a gene, designated FOW2, which encodes a putative transcription regulator belonging to the Zn(II)2Cys6 family. The REMI mutant B137 and other FOW2-targeted mutants completely lost pathogenicity, but were not impaired in vegetative growth and conidiation in cultures. Microscopic observation of infection behaviours of green fluorescent protein (GFP)-marked wild-type and mutant strains revealed that the mutants were defective in their abilities to invade roots and colonize plant tissues. FOW2 is conserved in F. oxysporum pathogens that infect different plants. The FOW2-targeted mutants of the tomato wilt pathogen F. oxysporum f. sp. lycopersici also lost pathogenicity. Nuclear localization of Fow2 was verified using strains expressing Fow2-GFP and GFP-Fow2 fusion proteins. These data strongly suggest that FOW2 encodes a transcription regulator controlling the plant infection capability of F. oxysporum pathogens.
Imazaki
Iori
I
Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya 464-8601, Japan.
Kurahashi
Makoto
M
Iida
Yuichiro
Y
Tsuge
Takashi
T
D000595:Amino Acid Sequence; D005656:Fungal Proteins / Q000737:chemistry / Q000378:metabolism*; D005670:Fusarium / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism / Q000472:pathogenicity*; D015966:Gene Expression Regulation, Fungal; D049452:Green Fluorescent Proteins / Q000378:metabolism; D008969:Molecular Sequence Data; D016296:Mutagenesis; D010935:Plant Diseases / Q000382:microbiology; D018517:Plant Roots / Q000382:microbiology; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism*; D014170:Transformation, Genetic; D016335:Zinc Fingers
D005656:Fungal Proteins; D014157:Transcription Factors; D049452:Green Fluorescent Proteins