The auxin responsive gene Pp‐C61 is up‐regulated in Pinus pinaster roots following inoculation with ectomycorrhizal fungi

Abstract

M . Up-regulation was found to be a primary (direct) response to auxin. Ethylene and abscisic acid, but not quercetin were able to promote Pp-C61 mRNA accumulation. As a putative extracellular protein, Pp-C61 was postulated to play a role in ectomycorrhiza formation. Pp-C61 was upregulated in P. pinaster roots following inoculation with ectomycorrhizal fungi. Transcript accumulation was the highest (5.5-fold over control) in the presence of an IAAoverproducing mutant of Hebeloma cylindrosporum ; it was less in the presence of wild-type strains of H. cylindrosporum and Rhizopogon roseolus . Pp-C61 transcript also accumulated upon inoculation with a non-mycorrhizal mutant of H. cylindrosporum . These results suggest that Pp-C61 up-regulation corresponds to a defence reaction in response to fungal colonization.

ESTs Analysis Reveals Putative Genes Involved in Symbiotic Seed Germination in Dendrobium officinale

“…A phytohormone-related gene encoding auxin response protein was also discovered and seems to be upregulated in SGS. The auxin response protein had been reported to function in defense response in Pinus pinaster roots against fungal pathogen attacks [43]. …”

Cross talks at the morphogenetic, physiological and gene regulation levels between the mycobiont Piloderma croceum and oak microcuttings (Quercus robur) during formation of ectomycorrhizas

“…Such banks can serve to develop microarrays for following transcriptomic responses to the EM state in fungi or plant (Peter et al, 2003;Johansson et al, 2004;Wright et al, 2005;LeQuéré et al, 2005), or the response of EM to specific environmental factors such as heavy metals (Jacob et al, 2004). These banks may also be the starting point for regulation studies of one gene in response to EM inoculation or a given biological compound such as auxins in order to enlighten its function (Balasubramanian et al, 2002;Reddy et al, 2003;Tagu et al, 2003).…”

Communication and Signaling in the Plant–Fungus Symbiosis: The Mycorrhiza

“…The presence of plantderived molecules in the rhizosphere could be sufficient to enhance the biosynthesis of hormones by ectomycorrhizal fungi (Rupp et al 1989) , which induce morphological changes leading to symbiosis development. For example, an IAA-upregulated cDNA, referred to as Pp-C61, was isolated by the differential screening of a cDNA library constructed from auxin-treated roots of the ECM host tree Pinus pinaster (Reddy et al 2003) . Pp-C61 is present as a single copy in the P. pinaster genome, and homologous genes were detected in other gymnosperm and angiosperm trees.…”