A new fungus-mediated RNAi method established and used to study the fatty acid and retinol binding protein function of the plant-parasitic nematode .

RNA interference (RNAi) is a powerful tool for gene functional analysis of plant-parasitic nematodes (PPNs). RNAi involving soaking in a dsRNA solution and methods is commonly applied in the study of gene function in PPNs. However, certain problems restrict the application of these methods. Therefore, more convenient and effective RNAi methods need to be established for different PPNs according to their biological characteristics. In this study, the fatty acid and retinoid binding protein genes (, and combinatorial and ) of the rice white tip nematode (RWTN), , were used as target genes to construct a fungal RNAi vector, and the dsRNA transgenic (ARTB) were generated using -mediated transformation technology. After RWTN feeding on ARTB, the expression of and in the nematodes was efficiently silenced, and the reproduction and pathogenicity of the nematodes were clearly inhibited. The and co-RNAi effects were better than the effects when each gene was individually targeted with RNAi. Additionally, the RNAi induced when RWTNs fed on ARTB were persistent and heritable. Thus, a new method of fungus-mediated RNAi was established for fungivorous PPNs and was verified as effective and applicable to the study of nematode gene function. This technique will remove the technological bottlenecks and provide a new method to studying the multiple genes with polygene co-RNAi in fungivorous PPNs. This study also provides a theoretical basis and new thought for further study of the gene function in PPNs. FAR(Fatty acid and retinol-binding proteins); RWTN (The rice white tip nematode, (Fatty acid and retinol binding protein gene of ; ARTB ( hpRNA transgenic ); ARTB ( hpRNA transgenic ); ARTB/ (combinatorial and hpRNA transgenic ); EVTB (Empty vector transgenic ); GRTB (eGFP hpRNA transgenic ); WTB (Wild-type ).