Significance of ABC transporters in fungicide sensitivity and resistance

ATP‐binding cassette (ABC) transporters are members of a protein superfamily which can be responsible for efflux of drugs from cells of target organisms. In this way, the transporters may provide a mechanism of protection against cytotoxic drugs. In laboratory‐generated mutants of fungi, overproduction of ABC transporters can cause multi‐drug resistance to azoles and other non‐related toxicants. The impact of this mechanism of resistance in field populations with decreased sensitivity to azoles remains to be established. Inhibitors of ABC transporter activity may synergize activity of azoles to populations of both sensitive and azole‐resistant pathogens. The natural function of ABC transporters in plant pathogenic fungi may relate to transport of plant‐defence compounds or fungal pathogenicity factors. Therefore, inhibitors of ABC transporter activity may act as disease control agents with an indirect mode of action. ©1997 SCI