Research On The Function Of Candidate Genes For Resistance To Wildfire Disease In Tobacco

In recent years,tobacco wildfire disease has become one of the main diseases in tobacco industry in Heilongjiang province.Making full use of resistant materials to breed resistant tobacco varieties is an effective way to deal with the disease.However,the nature and mechanism of disease resistance genes in tobacco materials are not clear.Although the mechanism of Pto gene against the disease through ETI(Effector-triggered immunity)pathway in tomato has been reported for a long time.Nicotiana alata Link et Otto is a resistant material to Tobacco Wildfire Race 0.With the ETI(Effector-triggered immunity)pathway,selecting one candidate gene NL-HERK derived from transcriptome analysis,testing its function with the methods of overexpression and RNAi strategy,this paper provides a research basis for the interpretation of ETI pathway in Nicotiana alata Link et Otto.Through the experiment,the NL-HERK overexpression vector pROK Ⅱ-NL-HERK and tomato Pto gene overexpression vector pROK Ⅱ-Pto were constructed respectively.With the susceptible tobacco LJ0520 as receptor material,using the way of Agrobacterium-mediated Genetic Transformation,24 tobacco strains transformed with Nicotiana alata Link et Otto NL-HERK were obtained.With the susceptible tobacco LJ911 as receptor material,using the way of Agrobacterium-mediated Genetic Transformation,18 tobacco stains transformed with tomato Pto were obtained.The pathological tests and molecular identification of the transgenic tobacco and wild type tobacco were carried out by acupuncture method.The results showed that the transgenic tobacco had no resistance to tobacco wildfire disease.In order to further verify the function of NL-HERK,the RNAi expression vector pRNAi-NL-HERK was constructed and 24 transformed strains were obtained by Agrobacterium tumefaciens mediated transformation.Pathological tests showed that some of the transformed strains were susceptible to the disease.Based on the work of this paper,the following conclusions can be drawn:1.There are defects in ETI resistance pathway in susceptible tobacco,but the defect is not in Pto genes themselves.2.There is a ETI resistance pathway in Nicotiana alata Link et Otto,in which NL-HERK gene is involved.