By "effectors" we mean parasite-encoded proteins that directly affect the host biology. Bacteria have been at the forefront of the study of "effectors". On one hand, the role and mode of action of a few of these bacterial effectors has been elucidation, on the other hand many new pathogenic bacteria genomes are available with many type III effectors for which little if known. It is clear that other, extracellular plant parasitic organisms like nematode, oomycetes and fungi also can "transfer" some of their encode proteins into the host plant cell.
In this section we propose to provide a specific snapshots of the effectors from these four groups of plant pathogens