Plant:virus interactions involved in viral cell-to-cell spread

HEINLEIN, MANFRED; AMARI, KHALID; NIEHL, ANNETTE; PITZALIS, NICOLAS; KORNER, CAMILLA; PEÑA, EDUARDO

Berlin

Workshop; Intercellular communication in development and disease; 2017

Plant viruses and their movement proteins (MP) target plasmodesmata (PD) for cell-to-cell movement and rely on cellular transport pathways and mechanisms by which informational macromolecules are targeted to PD. Our team investigates these mechanisms in the context of virus:host interactions at the level of gene expression and defense responses, and aims to unravel important mechanisms leading to disease. Using Tobacco mosaic virus (TMV) as a model we found that this virus uses its movement protein (MP) to target junctions between the cortical ER-actin network and microtubules (MT) for replication, and that the ER-actin network and associated myosins transport the viral replication complexes to and through PD. dsRNA produced during replication triggers RNA silencing as well as Pattern?Triggered Immunity (PTI), and we are interested to understand how the virus takes control over these defenses to facilitate its spread. Currently, we use next generation sequencing approaches to determine the function of virus- and host-derived small RNAs and their RNA targets, as well as the role of the viral silencing suppressor in controlling these activities, during virus replication and spread. Our team also wants to know why certain plants react to virus infection with disease while other plants are rather tolerant to same virus. One way to approach this question is by analysis of recovery, which refers to the occurrence of healthy leaves on symptomatic plants. To understand the underlying process, we identified a virus:host interaction in Arabidopsis that initially produces strong developmental symptoms and achieves a tolerant state at later stages. Genetic analysis led to the identification of genes and pathways required for recovery and which may play an important role in tolerance, thus allowing plants to remain healthy in the presence of viruses in the environment.