Figure 1.

Diagram of fungal and bacterial delivery of known and candidate effectors that influence chloroplast function. The left side of the diagram depicts the interaction of a fungal pathogen with a plant cell to deliver effectors by mechanisms that could involve colonization of the apoplast, penetration of host cells or formation of haustorial feeding structures. Known effectors (Cmu1 and ToxA) are shown with ToxA localized to the chloroplast. Candidate effectors (CTP1, 2 and 3) are localized to the chloroplast, but their impact of function is not yet known. The right side of the diagram shows the delivery of effectors by bacterial pathogens via a type III secretion system. Representative effectors delivered by Pseudomonas syringae are listed.