Chapter Eleven - Emerging Roles of Cyst Nematode Effectors in Exploiting Plant Cellular Processes

Diverse phytonematodes deliver effector proteins into the cells of their plant hosts using a hollow, protrusible mouth spear called a stylet. Collectively, these stylet-secreted effector (SSE) proteins function to modulate cellular processes that favour nematode growth and development. We discuss the functions of SSEs, with an emphasis on cyst nematodes. Identified plant targets of several cyst nematode effectors have revealed their putative function in parasitism. Several cyst nematode effectors modulate host developmental pathways and alter phytohormone balance to favour feeding site establishment. Other effectors are deployed to various plant compartments to subvert plant stress and defence responses. We also discuss genome-aided discovery of the entire complement of cyst nematode effectors that promises to uncover the full range of effector functions and enable comparative analyses that address outstanding questions in plant-cyst nematode interactions such as the molecular basis of host specificity.