Transcription of a gene encoding a lectin-like glycoprotein is induced in root cells harboring arbuscular mycorrhizal fungi in Pisum sativum.

The gene PsNlec1, which encodes a lectinlike glycoprotein, is strongly expressed in pea nodule tissue. Using genespecific polymerase chain reaction (PCR) primers, in situ hybridization probes, and specific antisera derived from the PsNlec1 sequence, we investigated gene expression associated with the arbuscular mycorrhizal (AM) symbiosis of pea roots. With the use of reverse transcription (RT)- PCR and cold in situ hybridization, strong expression of the transcript was demonstrated not only in root nodules but also in mycorrhizal roots when the cells were colonized by the endomycorrhizal fungus Glomus versiforme. No transcript was detectable in uninfected pea roots. With an antiserum raised against PsNLEC-1 polypeptide, a single antigenic band (25 kDa) was observed following gel electrophoresis of extracts from mycorrhizal roots. However, the amount of antigen was apparently too low to be detected by immunogold localization in tissue sections of pea mycorrhizal roots.