Since its discovery in 2012, the role of the trichovirus named grapevine Pinot gris virus (GPGV) as the causative agent of grapevine leaf mottling and deformation (GMLD) syndrome, a grapevine disease for which symptoms had been observed in north Italy and western Slovenia a few years earlier, has been a matter of discussion. In the following 10 years of investigations, evidence has emerged of a role for the genetic diversity of the virus and for the varietal diversity of the host, as well as their interaction during antiviral defence (i.e. RNA silencing) and virus-mediated defence suppression. In a context of wider research efforts, several relevant aspects of GPGV evolution and GMLD epidemiology were also clarified. Nevertheless, a complete understanding of the molecular events and the environmental conditions that could affect viral infection severity and symptom display remains a challenging puzzle. In the meantime, we are witnessing a large spread of the virus, which has almost completely permeated the regions where it first appeared, while spreading through most areas of grapevine cultivation. A deeper knowledge of the molecular context of the disease is key to establishing whether the impressive potential of GPGV to spread makes it a candidate as the next emerging threat for the grapevine industry.
