The root-knot nematodes engage in sophisticated interactions with their host plants inducing the formation of permanent feeding sites. Within the vascular cylinder, these feeding sites consist of giant cells that are multinucleate, hypertrophied, and metabolically highly active and serve as food sources throughout the nematode life cycle. Nematode parasitism proteins synthesised in the oesophageal glands of the nematode are secreted into the host plants via a syringe-like stylet and play a key role in manipulating the host machinery for giant cells ontogenesis. Comparative genomics and transcriptomics allowed us to repertoryM. incognitaeffector proteins. Within the host cells, these nematode effectors target different subcellular domains and may assume very diverse cellular functions. Using immunocytochemical approaches, we showed that the plant apoplasm acts as an important destination compartment for effector proteins involved in protein degradation and cell wall modification that are secreted during migration and sedentary stages of the nematode. We showed that a protein specifically expressed in the oesophageal glands of parasitic juveniles is secreted within the host cells where it targets nuclei and may manipulate nuclear functions to allow parasitism. Functional analysis of these effectors is ongoing, which will help deciphering their roles in targeting and manipulating host functions.
- Vieira P., Danchin E.G.J., Neveu C., Crozat C., Jaubert S., Hussey R.S., Engler G., Abad, P., de Almeida-Engler J., Castagnone-Sereno P. and Rosso M.N. (2011). The plant apoplasm is an important recipient compartment for nematode secreted proteins.Journal of Experimental Botany 62: 1241-1253.
- Jaouannet M, Perfus-Barbeoch L, Deleury E, Magliano M, Engler G, Vieira P, Danchin EGJ, Da Rocha M, Coquillard P, Abad P, Rosso MN. (2012) A root-knot nematode secreted protein is injected into giant-cells and targeted to the nuclei.New Phytologist194(4):924-31.