A fungal protease named AsES triggers antiviral immune responses and effectively restricts virus infection in arabidopsis and Nicotiana benthamiana plants

Background and Aims: Plants have evolved complex mechanisms to fight against pathogens. Among these mechanisms, pattern-triggered immunity (PTI) relies on the recognition of conserved microbe- or pathogen-associated molecular patterns (MAMPs or PAMPs, respectively) by membrane-bound receptors. Indeed, PTI restricts virus infection in plants and, in addition, BRI1-associated kinase 1 (BAK1), a central regulator of PTI, plays a role in antiviral resistance. However, the compounds that trigger antiviral defences, along with their molecular mechanisms of action, remain mostly elusive. Herein, we explore the role of a fungal extracellular subtilase named AsES in its capacity to trigger antiviral responses. Methods: In this study, we obtained AsES by recombinant expression, and evaluated and characterized its capacity to trigger antiviral responses against Tobacco mosaic virus (TMV) by performing time course experiments, analysing gene expression, virus movement and callose deposition. Key Results: The results of this study provide direct evidence that exogenous treatment with recombinant AsES increases a state of resistance against TMV infection, in both arabidopsis and Nicotiana benthamiana plants. Also, the antiviral PTI response exhibited by AsES in arabidopsis is mediated by the BAK1/SERK3 and BKK1/SERK4 co-receptors. Moreover, AsES requires a fully active salicylic acid (SA) signalling pathway to restrict the TMV movement by inducing callose deposition. Additionally, treatment with PSP1, a biostimulant based on AsES as the active compound, showed an increased resistance against TMV in N. benthamiana and tobacco plants. Conclusions: AsES is a fungal serine protease which triggers antiviral responses relying on a conserved mechanism by means of the SA signalling pathway and could be exploited as an effective and sustainable biotechnology strategy for viral disease management in plants.

Instituto de Biotecnología

Fil: Caro, María del Pilar. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; Argentina

Fil: Caro, María del Pilar. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Fil: Caro, María del Pilar. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Famaillá; Argentina

Fil: Venturuzzi, Andrea Laura. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; Argentina

Fil: Venturuzzi, Andrea Laura. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Fil: Moschen, Sebastian Nicolas. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Famaillá; Argentina

Fil: Moschen, Sebastian Nicolas. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Fil: Salazar, Sergio Miguel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Famaillá; Argentina

Fil: Diaz Ricci, Juan Carlos. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; Argentina

Fil: Diaz Ricci, Juan Carlos. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química Biológica Dr. Bernabé Bloj; Argentina

Fil: Diaz Ricci, Juan Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Fil: Asurmendi, Sebastian. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; Argentina

Fil: Asurmendi, Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina