Cellular localization of PSAM 1, a novel plant protein in arbuscular mycorrhiza of Pisum sativum

MARTIN-LAURENT, FABRICE¹, CHRISTINE ARNOULD¹, ODILE CHATAGNIER¹, DIEDERIK VAN TUINEN¹, PHILIPP FRANKEN², SILVIO GIANINAZZI¹ & VIVIENNE GIANINAZZI-PEARSON¹.

¹Laboratoire de Phytoparasitologie, INRA/CNRS, CMSE-INRA, BV 1540, 21034 Dijon Cedex, FRANCE. ²Max-Planck-Institut für Terrestrische Mikrobiologie, Abteilung Biochemie und Laboratorium für Mikrobiologie, Philipps-Universität, Karl-von-Frisch-Strasse, D-35043 Marburg, Germany.

Psam 1 is a single copy gene activated during early plant-fungal interactions in wild-type pea inoculated with Glomus mosseae (BEG 12) and which codes for PSAM 1, a putative protein of 108 amino acids. A synthetic peptide was designed in an antigenic region of this protein to produce a polyclonal antibody against PSAM 1 and to investigate its cellular localization. DIBA and Western blot analyses revealed that a polypeptide of about 14.5 kDa accumulated more in mycorrhizal than non-mycorrhizal pea roots. PSAM1 antigen was immunolocated in planta in arbuscule-containing cells of mycorrhizal roots and especially in the cytoplasm surrounding young arbuscules in cortical cells which suggests that its accumulation is somehow related to the symbiotic state of these cells.

Key words: Glomus mosseae - Pisum sativum L. - immunocytochemistry - SR protein.