纳米硒化荧光假单胞菌KBD-1菌株对烟草病毒病的抑制作用

为挖掘具有纳米硒化能力的生防菌株，开发烟草病毒病的绿色防治材料，从烟草病毒病重病田块健株根际土壤中筛选获得到一株荧光假单胞菌Pseudomonas fluorescens KBD-1，对其进行了纳米硒化，采用Real-time PCR和Western blot测定了两者对烟草常见病毒基因表达的影响，并采用接种法测定了其对烟株相应病毒病的防治作用。结果表明，纳米硒化后的KBD-1菌体外部存在高密度电子颗粒，在X射线11.22 keV处出现硒的特征吸收峰。纳米硒化后的P.fluorescens KBD-1菌液浓度在5×10⁵ cfu/mL（单质硒浓度0.25 mg/L）时，对烟草花叶病毒（TMV）、马铃薯Y病毒（PVY）、黄瓜花叶病毒（CMV）、番茄斑萎病毒（TSWV）4种病毒病的防治效果均在88.0%以上，对CMV防治效果最高达91.4%，该浓度处理对烟株促生效果显著。荧光假单胞菌KBD-1可成功将亚硒酸钠还原生成纳米硒，并能增强原始菌株的抗烟草病毒活性和促生效果。

Inhibition of Tobacco Virus Diseases by Nano-selenated Pseudomonas fluorescens KBD-1

In order to explore biocontrol strains with nano-selenized ability and develop green antiviral materials to prevent tobacco virus diseases, Pseudomonas fluorescens KBD-1 was identified from the rhizosphere soil of healthy plants in the field with serious tobacco virus diseases. The nano-selenized activity of P. fluorescens KBD-1 was investigated in this study, and its inhibitions against four main tobacco viruses were determined by using the methods including Real-time PCR and Western blot under the treatments of original strain and nano-selenized strain. The results showed that there were high density electron particles outside the nano-selenized KBD-1 and the characteristic absorption peak of selenium appeared at 11.22 keV X-ray. When the concentration of P. fluorescens KBD-1 bacterial fluid after nano-selenization was 5×10⁵ cfu/mL (0.25 mg/L selenium), the control effects against Tobacco mosaic virus (TMV), Potato virus Y (PVY), Cucumber mosaic virus (CMV) and Tomato spotted wilt virus (TSWV) were all above 88.0%, and the highest control effect against CMV was 91.4%. The treatment at this concentration also had significant growth-promoting effect on tobacco plants. This study showed that P. fluorescens KBD-1 successfully reduced sodium selenite to produce nano-selenium, and enhanced the antiviral activity and growth-promoting effect of the original strain.