A novel ABC transporter gene, PMR5, is involved in multidrug resistance in the phytopathogenic fungus Penicillium digitatum.
We have cloned a novel ABC transporter gene PMR5 from the phytopathogenic fungus Penicillium digitatum by RT-PCR using degenerate primers. The deduced amino acid sequence of PMR5 showed 37% identity to PMR1 from the same fungus, 71% identity to AtrB from Aspergillus nidulans, and 65% identity to BcatrB from Botrytis cinerea. Disruption mutants for PMR5 were generated in two independent P. digitatum strains and their phenotypes were characterized. These mutants displayed increased sensitivity to thiabendazole (a benzimidazole), benomyl (a benzimidazole), dithianon (a quinone), resveratrol (the phytoalexin of grape), and camptothecin (an alkaloid). Delta pmr1 disruption mutants were previously reported to show resistance to demethylation inhibitors (DMIs). These mutants were found also to display increased sensitivity to phloretin (the phytoanticipin of apples), camptothecin and oligomycin (an antibiotic). Transcription of PMR1 and PMR5 was strongly induced in response to several toxicants, including DMIs that specifically induced PMR1. In contrast, dithianon and resveratrol specifically induced PMR5 transcription. These findings indicate that expression of the two ABC transporter genes is regulated differently, and that they have complementary roles in multidrug resistance, with each having different substrate-specificities.
Nakaune
R
R
Laboratory of Plant Pathology, Department of Grape and Persimmon Research, National Institute of Fruit Tree Science, Akitsu-cho, Hiroshima 729-2494, Japan. une@affrc.go.jp
Hamamoto
H
H
Imada
J
J
Akutsu
K
K
Hibi
T
T
D018528:ATP-Binding Cassette Transporters / Q000235:genetics*; D000595:Amino Acid Sequence; D000935:Antifungal Agents / Q000494:pharmacology; D001233:Aspergillus nidulans / Q000235:genetics; D001426:Bacterial Proteins; D001483:Base Sequence; D020171:Botrytis / Q000235:genetics; D003001:Cloning, Molecular; D004271:DNA, Fungal / Q000235:genetics; D026141:Drug Resistance, Multiple, Fungal / Q000235:genetics*; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects; D005800:Genes, Fungal; D008969:Molecular Sequence Data; D009154:Mutation; D010407:Penicillium / Q000187:drug effects / Q000235:genetics* / Q000472:pathogenicity; D010944:Plants / Q000382:microbiology; D015533:Transcriptional Activation / Q000187:drug effects
D018528:ATP-Binding Cassette Transporters; D000935:Antifungal Agents; D001426:Bacterial Proteins; D004271:DNA, Fungal; C115447:Pmr1 protein, bacteria