Global impact: elucidating plant responses to viral infection.

Viruses induce a variety of responses in host cells that are mediated by perturbation of different signaling pathways. Advances in our understanding of the functions of viral proteins, plant biology in general, as well as technologies for profiling gene expression have converged in recent years to provide new insight into the events occurring inside susceptible and resistant host cells in response to virus infection. These effects range from nonspecific changes in gene expression due to the general accumulation of viral proteins to those responses that are initiated by the specific interactions between virus and host proteins. Here, we discuss a variety of expression profiling methods and approaches that have been used to study the effects of viruses on host transcriptomes. These studies have identified distinct sets of genes that have altered expression profiles in response to viruses, including stress- and defense-related genes. The activities of viral RNA silencing suppressors and interference with hormone signaling or biogenesis also influence plant gene expression and lead to developmental abnormalities.