Proteomic and phosphoproteomic approaches to understand plant-pathogen interactions

The regulation mechanisms of any plant-pathogen interaction are complex and dynamic. A proteomic approach is valuable in understanding regulatory networks because it deals with identifying new proteins in relation to their function and ultimately aims to unravel how their expression and modification is controlled. One of the major control mechanisms for protein activity in plant-pathogen interactions is protein phosphorylation. However, studying protein phosphorylation cascades in plants presents two major technical challenges. The first is that many of the signaling components are present at very low copy numbers, which makes them difficult to detect. The second is that they are difficult to identify because there are currently only three plants with a complete genome sequence, i.e. Arabidopsis thaliana, Populus (poplar) and Oryza sativa (rice). In this article, we review proteomic approaches to study plant-pathogen interactions in both model and non-model plants and demonstrate that current proteomic and phosphoproteomic technologies have the potential to identify new components of regulatory pathways and elucidate their functions within a cellular context.