Interacciones Moleculares Planta-Virus-Vector

HCPro is a key non-structural protein of Potyviruses because it suppresses the plant antiviral defenses based on small RNA (sRNA)-based gene silencing, allowing for systemic infection of plants, and also because it mediates the horizontal dispersion of infection between plants by insect vectors. 

With regard to the former function, results from our lab have shown that HCPro prefers for association sRNAs of non-plant sequence that are of 21-22 nt in length and have 5´-end adenines (del Toro et al., 2017. J. Virology 91:e00367-17 and manuscript submitted).  Our results would be compatible with a model in which HCPro suppresses antiviral silencing by associating sRNAs of 21-22 nt with 5´-end adenines and viral sequence and also by concurrently blocking the methylation of the sRNAs being newly generated

Those results were obtained expressing in plants HCPro of the Potyvirus PVY either from a potexvirus vector, or transiently from T-DNAs.  We will now test this model in a real potyviral infection.  We will determine the populations of sRNAs generated during such infections, and those of them that associate to HCPro.  Since we lack a PVY clone that is infectious, we will either express suppression-competent and -deficient PVY HCPro variants from a heterologous Potyvirus, or study the properties of the heterologous HCPros.  We will analyse the sRNA populations by next generation sequencing (NGS).