In planta secretion of a calreticulin by migratory and sedentary stages of root-knot nematode.
Esophageal secretions from endoparasitic sedentary nematodes are thought to play key roles throughout plant parasitism, in particular during the invasion of the root tissue and the initiation and maintenance of the nematode feeding site (NFS) essential for nematode development. The secretion in planta of esophageal cell-wall-degrading enzymes by migratory juveniles has been shown, suggesting a role for these enzymes in the invasion phase. Nevertheless, the secretion of an esophageal gland protein into the NFS by nematode sedentary stages has never been demonstrated. The calreticulin Mi-CRT is a protein synthesized in the esophageal glands of the root-knot nematode Meloidogyne incognita. After three-dimensional modeling of the Mi-CRT protein, a surface peptide was selected to raise specific antibodies. In planta immunolocalization showed that Mi-CRT is secreted by migratory and sedentary stage nematodes, suggesting a role for Mi-CRT throughout parasitism. During the maintenance of the NFS, the secreted Mi-CRT was localized outside the nematode at the tip of the stylet. In addition, Mi-CRT accumulation was observed along the cell wall of the giant cells that compose the feeding site, providing evidence for a nematode esophageal protein secretion into the NFS.
INRA-CNRS-UNSA, Plant-Microbe Interactions and Plant Health, 400 route des Chappes BP 167, 06903 Sophia Antipolis, France.
Stéphanie
S
Jaubert
Adina L
AL
Milac
Andrei J
AJ
Petrescu
Janice
J
de Almeida-Engler
Pierre
P
Abad
Marie-Noëlle
MN
Rosso
D000595:Amino Acid Sequence; D000818:Animals; D017360:Arabidopsis / Q000378:metabolism / Q000469:parasitology; D037282:Calreticulin / Q000737:chemistry / Q000378:metabolism*; D005786:Gene Expression Regulation; D018551:Solanum lycopersicum / Q000378:metabolism / Q000469:parasitology; D008958:Models, Molecular; D008969:Molecular Sequence Data; D018517:Plant Roots / Q000378:metabolism / Q000469:parasitology*; D021381:Protein Transport; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014431:Tylenchoidea / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*
D037282:Calreticulin