Transcriptome analysis of root-knot nematode functions induced in the early stages of parasitism*

Authors


  • *

    The nucleotide sequence data have been submitted to GenBank and dbEST.

Author for correspondence: Marie-Noëlle Rosso
Tel: +33 492386504
Fax:+33 492386587
Email: rosso@sophia.inra.fr

Summary

  • • Root-knot nematodes of the genus Meloidogyne are obligate biotrophic parasites able to infest > 2000 plant species. The nematode effectors responsible for disease development are involved in the adaptation of the parasite to its host environment and host response modulation.
  • • Here, the differences between the transcriptomes of preparasitic exophytic second-stage juveniles (J2) and parasitic endophytic third-stage juveniles (J3) of Meloidogyne incognita were investigated.
  • • Genes up-regulated at the endophytic stage were isolated by suppression subtractive hybridization and validated by dot blots and real-time quantitative polymerase chain reaction (PCR).
  • • Up-regulation was demonstrated for genes involved in detoxification and protein degradation, for a gene encoding a putative secreted protein and for genes of unknown function. Transcripts of the glutathione S-transferase gene Mi-gsts-1 were 27 times more abundant in J3 than in J2. The observed Mi-gsts-1 expression in the oesophageal secretory glands and the results of functional analyses based on RNA interference suggest that glutathione S-transferases are secreted during parasitism and are required for completion of the nematode life cycle in its host. Secreted glutathione S-transferases may protect the parasite against reactive oxygen species or modulate the plant responses triggered by pathogen attack.

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