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Poster: Molecular & Cellular Plant-Microbe Interactions: MPMI


Functional analysis of root-knot nematode (Meloidogyne javanica) virulence genes in rice.
D. FERNANDEZ (1), D. Fernandez (2), M. Grossi de Sá (3), I. Mezzalira (4), M. Beneventi (4), M. Lisei de Sá (5), D. Amora (4), H. Baimey (6), A. Petitot (7), J. de Almeida Engler (8), É. Saliba Albuquerque (4), M. Grossi de Sá (4) (1) IRD - French Researc

Root-knot nematodes are endo-parasites with a wide host range, encompassing mono- and dicotyledonous plant crops. Meloidogyne javanica is responsible for rice (Oryza sativa) production losses in Brazil and Africa (Benin). Successful infection is likely achieved by effector proteins produced in the nematode esophageal gland cells and released in the host plant cells. The aim of this study was to assess the functional role of three esophageal gland cell proteins of M. javanica in rice - nematode interactions. RT-qPCR assays showed that Mj-SP2, Mj-SP18 and Mj-SP19 genes are over-expressed all along the infection cycle in rice roots. Immunodetection experiments using specific antibodies raised against synthetic peptides showed that the nematode proteins are localized in circular granules structures within the nematode body. Transgenic rice (O. sativa Nipponbare) plants expressing the candidate proteins or artificial micro-RNAs (amiRNAs) able to silence the cognate genes in the nematode were produced. Assessment of nematode reproduction on homozygous transgenic lines allowed the identification of rice lineages with altered susceptibility, indicating that these proteins may be involved in M. javanica virulence. Data obtained significantly widen our knowledge of molecular players contributing to nematode pathogenicity, and open new avenues for nematode control strategies in rice and other crops of interest.