黄瓜转新型抗菌蛋白基因GNK2-1及其抗枯萎病的研究

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。

Overexpression of a Novel Antifungal Protein Gene GNK2-1 Results in Elevated Resistance of Transgenic Cucumber to Fusarium oxysporum

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.