GNK2-1为一种来自银杏(Ginkgo biloba)种仁的新型抗真菌蛋白, 具有较强的真菌抗性且性质稳定。序列分析表明,其结构与所有已知的抗真菌蛋白不同, 而与富含半胱氨酸的植物类受体激酶的胞外结构域相似。为探索GNK2-1基因在黄瓜(Cucumis sativus)抗病反应中的作用, 利用基因重组技术构建了GNK2-1的高效组成型表达载体, 并利用根癌农杆菌(Agrobacterium tumefaciens)介导转入黄瓜栽培品种农城3号(Cucumis sativus ‘Nongcheng No.3’)基因组中。通过对获得的抗性植株进行PCR、RT-PCR和Western blot检测分析, 结果表明GNK2-1基因可在T₀代转基因植株中转录表达, 并能在T₁代转基因黄瓜中稳定遗传。离体枯萎病抗性鉴定结果表明, 转GNK2-1基因的黄瓜对枯萎病的抗性增强, GNK2-1可以作为黄瓜抗病性改良的潜在基因资源。

A novel antifungal protein, ginkbilobin2-1 (GNK2-1), from Ginkgo biloba seed kernels, was proved to have a stable and significant inhibition effect on fungus growth. The protein showed no similarity to other pathogenesis-related proteins but did show homology to the extracellular domain of plant cysteine-rich receptor-like kinases. In order to improve resistance of transgenic plants to fungal infection, we used RT-PCR to amplify GNK2-1 from G. biloba seeds and transformed the gene into cucumber (Cucumis sativus) cultivar Nongcheng 3 via Agrobacterium-mediated method. Transgenic plants were obtained and the expression of the transgene was confirmed by PCR, RT-PCR and western blot analysis. Resistance tests against Fusarium oxysporum showed that expression of the GNK2-1 in transgenic cucumber plants conferred antifungal activity against this disease. The GNK2-1 gene may be a good candidate for breeding new cucumber varieties with resistance to fungal blight disease.