Alterations of the Turnip Vein Clearing Virus spreading in Arabidopsis thaliana over-expressing pectin methylesterase inhibitors

The ability of viruses to cross the plant cell wall to propagate infection throughout a plant is based on interactions among viral and host factors. The cell wall located pectin methylesterase enzyme (PME) is one of these factors. It is established that PME can act as host-cell receptor of Tobacco mosaic virus movement protein (TMV-MP) and also that the PME-MP interaction is required for cell-to-cell movement of the virus through plasmodesmata. Plant PMEs have also been shown to interact with MP from other viruses such as Turnip vein clearing virus (TVCV) and Cauliflower mosaic virus (CaMV) suggesting this interaction as possibly being involved in the cell-to-cell movement of the virus. However, the role of the PME-MP interaction to virus movement has not been elucidated. PME activity in plant is regulated by several factors including the apoplastic pectin metylesterase inhibitors (PMEIs). With the aim to better clarify the mechanism of virus movement in planta and to possibly counteract the viral infection we have generated Arabidopsis plants over-expressing PMEI. In these plants we have analyzed the changes of TVCV spreading in comparison to untransformed control plants.