Benzimidazole resistance of Gibberella zeae.(anonmorph: Fusarium graminearum) was conferred by point mutation in β2-tubulin gene (FGSG_ 06611.3, designated as β2tub), rather than β1-tubulin gene (FGSG_ 09530.3, designated as β1tub).Comparing with the β2tub, however, the β1tub of G.zeae had a much higher ho mology to the β-tubulin genes of other plant pathogenic fungus, which conferred the resistance to benzimidazole fungi cides.To determine whether the β1 tub of G.zeae has the potential ability to confer carbendazim-resistance, the site directed mutagenesis followed by gene replacement was used to change the β1tub of wild-type G.zeae strain 2021 at residue 50 (Tyr to Cys), residue 167 (Phe to Tyr), residue 198 (Glu to Lys) and residue 200 (Phe to Tyr),respectively.Comparing with 2021-derived β1tub revertant strains, all the β1tub mutant strains (Tyr50Cys, Phe167Tyr, Glu198Lys and Phe200Tyr) possessed low resistance to benzimidazole fungicides, such as carbendazim, benomyl, thiabendazole and thiophanate-methyl.There were no significandy changes among 2021, 2021-derived β1tub revertant-and β1tub mutant strains in the other biological properties.Thus, the β1tub in G.zeae was still a potential resistance gene against benzimidazole fungicides.