PtSRR1, a putative Pisolithus tinctorius symbiosis related receptor gene is expressed during the first hours of mycorrhizal interaction with Castanea sativa roots

Abstract

PtSRR1 EST was previously identified in the first hours of Pisolithus tinctorius and Castanea sativa interaction. QRT-PCR confirmed PtSRR1 early expression and in silico preliminary translated peptide analysis indicated a strong probability that PtSRR1 be a transmembrane protein. These data stimulate the PtSRR1 gene research during ectomycorrhiza formation.

The full length <i>PtSRP</i> (<i>Pisolithus tinctorius</i> symbiosis related protein) fungal mRNA encodes a potential marker of ectomycorrhiza formation

“…To the best of our knowledge, there is no report of SRAPs expression during shorter intervals, such as within early hours of mycorrhizal establishment. PtSRP QRT-PCR data [11] confirmed the cDNA microarray analysis [3] of its high relative transcription at 12 h of ectomycorrhizal stimulus.…”

“…The PtSRP post-translation modification sites previously indicated [11] were confirmed after obtention of the full-length mRNA. In addition, the prediction of a transmembrane region (composed of an alpha-helix between the 10 th and the 20 th a.a. residues) in the protein with a probable cleavage site close to the membrane, and an external portion composed of beta-sheets interspersed with loops were observed.…”

“…Transcription of this gene apparently does not occur until 6 h of contact, suggesting that the period between 6 and 12 h can be crucial for the PtSRP expression [11]. The complete PtSRP mRNA sequence showed 78% identity with a Pisolithus microcarpus sequence (CB010071; [14]) in ectomycorrhizal association with Eucalyptus globulus.…”

“…The 5' RACE technique generated a partial 355 bp fragment corresponding to the 5' portion of PtSRP mature mRNA (deposited at NCBI as nucleotide record GU733-439). The complete sequence, assembled by contig construction between the 5' RACE fragment and a 3' previously reported sequence (EL563703, [11]) resulted in a 636 bp sequence (Figure 1). Additionally, a unique 604 bp product was obtained by direct PCR of fungal cDNA samples.…”

“…The identification of new early stage ectomycorrhizal molecules could bring new insight to the molecular and functional understanding of the ectomycorrhiza formation process. The fungal PtSRP mRNA (previously called Pisolithus tinctorius symbiosis related receptor 1, accession number EL563703) was isolated [3] and partialy characterized [11] as a possible fungal membrane protein probably secreted in the first hours of fungus-root interaction. In this paper, we present the full-length PtSRP fungal mRNA sequence, supported by sequencing of the 5' region and our pre-viously reported 3' region, followed by in silico characterization of the most probable ORF and its relationship with early stages of ectomycorrhiza.…”