Molecular Mechanism Of Nerolidol Synthase1 Inhibiting Strawberry Vein Banding Virus Infection

Strawberry vein banding virus(SVBV)is one of the strawberry viruses that seriously harm the quality and yield of strawberry.Previous studies have found that the multifunctional protein P6 encoded by SVBV affects the pathogenicity of SVBV.The yeast c DNA library of forest strawberry infected with SVBV was screened using SVBV P6 as bait,and nerolidol synthase1(NES1)interacting with P6 was screened.NES1 plays an important role in plant growth and development by participating in biological and abiotic stresses and affecting plant disease resistance.In this study,the interaction between P6 and FvNES1 in vitro was first verified by yeast two-hybrid assay(Y2H),and the interaction between FvNES1 and P6 and the N terminal of P6 in vivo was verified by Bi FC experiment.Firefly luciferase interaction imaging analysis(LCI)and co-immunoprecipitation assay(Co-IP)further verified their interaction in plants.Confocal microscopy showed that FvNES1 was located in cytoplasm and nucleus,while P6 was located in inclusion bodies.The co-localization of both indicated that FvNES1 may directly target P6 and affect its function.In order to explore the role of FvNES1 in SVBV infection,the expression of FvNES1 gene was up-regulated in Fragariavesca inoculated with SVBV,and the expression of NES1 homologous gene of P6 transgenic Nicotiana benthamiana was also up-regulated,indicating that FvNES1 was involved in SVBV infection.P6 protein and FvNES1 protein were co-infiltrated into Nicotiana benthamiana.It was found that NES1 did not affect the expression of P6 protein or its silencing inhibition function.Exogenous spraying of SA,JA and ABA in Fragaria vesca showed that FvNES1 induced by SA,JA and ABA was significantly up-regulated,indicating that FvNES1 was related to plant resistance.The overexpression of FvNES1 in Nicotiana benthamiana inoculated TMV disease resistance,and the silence of Nb NES1 inoculated TMV disease susceptibility,FvNES1 gene was overexpressed in Fragariavesca using the modified TRV overexpression vector,and it was found that the overexpression of FvNES1 gene in Fragaria vesca symptoms was mild,indicating that FvNES1 could inhibit SVBV infection indicating that NES1 is a disease resistance gene.This study demonstrated that SVBV P6 and FvNES1 interact with each other to affect the process of virus infection in plants.It is of great significance to explore the relationship of infection and defense between SVBV and strawberry host factors to reveal the molecular mechanism of plant host resistance to ds DNA virus infection,strengthen and improve the control and breeding of strawberry virus disease resistance varieties.