Host-Pathogen Interactions

The relationships between viruses and their eukaryotic hosts have evolved over millions of years. To cause disease viruses must enter the host, multiply locally in host tissues and then spread from the site of entry; all the while overcoming or evading host immune responses. Plants have consequently evolved various anti-viral defense strategies. One strategy involves plant Resistance (R) gene products, which can detect the presence of a particular pathogen-encoded effector protein, often called an avirulence (Avr) protein. Another strategy is virus-induced gene silencing (VIGS) or post-transcriptional gene silencing (PTGS). Unlike the specific R gene-mediated resistance, PTGS is an adaptive immune response that allows a host to recognize viral nucleic acids and customize a sequence-specific response to clear viral infection. At the same time, viruses have evolved counter-defense strategies. For example, some viruses encode proteins that overcome VIGS or PTGS-mediated defense. Therefore, it is important to understand the molecular mechanisms by which viruses evade the hosts’ antiviral defenses.

We are studying:

• Resistance (R) gene-mediated defense

• Autophagy in plant innate immunity

• Viral pathogenesis factor P58 IPK