Eureka lemon zinc finger protein ClDOF3.4 interacts with citrus yellow vein clearing virus coat protein to inhibit viral infection1

Citrus yellow vein clearing virus (CYVCV) is a new citrus virus that has become an important factor restricting the development of China'scitrus industry, and the CYVCV coat protein (CP) is associated with viral pathogenicity. In this study, the Eureka lemon zinc finger protein (ZFP) ClDOF3.4 was shown to interact with CYVCV CP and . Transient expression of in Eureka lemon induced the expression of salicylic acid (SA)-related and hypersensitive response marker genes, and triggered a reactive oxygen species burst, ion leakage necrosis, and the accumulation of free SA. Furthermore, the CYVCV titer in transgenic Eureka lemon plants was approximately 69.4% that in control plants 6 months after inoculation, withonly mild leaf chlorotic spots observed in those transgenic plants. Taken together, the results indicate that ClDOF3.4 not only interacts with CP but also induces an immune response in Eureka lemon by inducing the SA pathways. This is the first report that ZFP is involved in the immune response of a citrus viral disease, which provides a basis for further study of the molecular mechanism of CYVCV infection.