Functional Analysis Of Atp-binding Cassette Transporter (abct) Genes In Fusarium Graminearum

Fusarium head blight (FHB) caused by Gibberlla zeae is one of the main diseases of cereal crops in China. Currently, highly resistant varieties of wheat are not available yet, thus, application of fungicides during wheat anthesis is the main approach for management to control of FHB. Since the methyl benzimidazole carbamate (MBC) fungicides have been used extensively to control FHB during the past three decades, MBC-resistant G. zeae populations have been developed in wheat field in many places of China. Previous studies on other fungal species have shown that over-expression of ATP-binding cassette (ABC) transporter genes is one of resistance mechanisms of fungi to fungicides. Additionally, ABC genes may play an important role in pathogenicity. To data, however, there is no any report on functions of ABC genes in G. zeae.In this study, using a gene deletion strategy, we obtained gene deletion mutants of 5 ABC genes (FGSG₀2786.3, FGSG₀6771.3, FGSG₁2704.3, FGSG₀3882.3, FGSG₁1272.3), which have completed structures of ABC transporters. Analyses of morphological characters showed that these mutants did not exhibit significant changes in mycelial growth on PDA, sensitivity to metal ions, osmotic and oxidative stresses. Pathogenicity tests showed that the FGSG₀6771.3 deletion mutants showed decreased virulence significantly on wheat head, indicating that this gene plays an important role on pathogenicity. Results of this study provide a basis for further investigation of the functions of ABC genes in G. zeae.