Increasing the targeting ability of antifungal proteins towards specific components of fungal cells has the potential to improve their antifungal activity and reduce harmful effects to nontarget cells. To obtain effective disease resistance genes against cotton Verticillium wilt, we constructed several fusion genes, in which binding domains targeting chitin, sphingolipid or ergosterol in the fungal cell wall or cell membrane were individually fused to the antifungal peptide BbAFP1 from entomopathogenic fungus Beauveria bassiana. Transient expression of fusion genes in cotton cotyledons indicated that the BbAFP1::ErBD fusion peptide with an ergosterol binding domain exhibited better disease resistance against V. dahliae than wild-type BbAFP1 and other fusion genes. BbAFP1::ErBD and BbAFP1 transgenic cotton were obtained and verified by Southern and Western blotting. Compared with BbAFP1-expressing cotton, BbAFP1::ErBD-expressing cotton showed higher disease resistance against V. dahliae, with smaller lesion areas (0.07 cm² vs. 0.16 cm²) on the leaves and a lower disease index (23.9 vs. 34.5). Overexpression of BbAFP1::ErBD by transgenic tobacco also showed enhanced disease resistance against V. dahliae compared with that of the wild-type gene. These results indicated that construction of fusion antifungal peptides that target fungal cells is a powerful strategy to obtain new anti-disease genes, and the obtained fusion gene BbAFP1::ErBD has the potential to defend against plant fungal diseases.

中文翻译：

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麦角甾醇靶向融合抗真菌肽显着提高棉花对黄萎病的抗性

提高抗真菌蛋白对真菌细胞特定成分的靶向能力有可能提高其抗真菌活性并减少对非靶细胞的有害影响。为了获得针对棉花黄萎病的有效抗病基因，我们构建了多个融合基因，其中针对真菌细胞壁或细胞膜中的几丁质、鞘脂或麦角甾醇的结合域分别与来自昆虫病原真菌白僵菌的抗真菌肽BbAFP1融合。融合基因在棉花子叶中的瞬时表达表明，具有麦角甾醇结合结构域的BbAFP1::ErBD融合肽比野生型BbAFP1和其他融合基因表现出更好的抗大丽弧菌抗病性。获得BbAFP1::ErBD和BbAFP1转基因棉花，并通过 Southern 和 Western blotting 进行验证。与表达BbAFP1的棉花相比，表达BbAFP1::ErBD的棉花对大丽花葡萄球菌的抗病性更高，叶片上的病斑面积更小（0.07 cm ² vs. 0.16 cm ² ），病害指数更低（23.9 vs. 34.5）。 ）。与野生型基因相比，转基因烟草过度表达BbAFP1::ErBD还表现出对大丽弧菌的抗病性增强。这些结果表明，构建靶向真菌细胞的融合抗真菌肽是获得新抗病基因的有力策略，所获得的融合基因BbAFP1::ErBD具有防御植物真菌病害的潜力。