Cloning plant genes differentially during colonization of roots of Hordeum vulgare by the vesicular—arbuscular mycorrhizal fungus Glomus intraradices

Abstract

SUMMARYA model system was developed for the molecular analysis of plant-mycorrhizal fungus interactions using Hordeum vulgare cv. Galleon and Glomus intraradices Schenk and Smith. High levels of early-colonization stage mycorrhizas (20-35 % of the total root length) were routinely obtained in the roots of 12-14-d-old barley seedlings. Detailed colonization studies showed that most colonization occurred in the first 5-10 lateral roots, and that colonization in primary roots and younger lateral roots was low. Differential screening of a cDNA library prepared from the highly colonized region of the root system and subsequent northern analyses identified four differentially expressed cDNA clones. Two clones, BMR6 and BMR78, detect RNA transcripts that accumulate to much higher levels in mycorrhizal roots than in non-mycorrhizal root tissues. DNA hybridization analysis confirmed that both of the clones were of plant rather than fungal origin. Hybridization and sequence analysis strongly suggests tliat BMR78 represents a partial cDNA of a low copy proton-ATPase gene. This finding is consistent with the extensive proliferation of the periarbuscular membrane and high ATPase activity associated with it. BM6 detects a low copy gene whose function is unknown.

Detection of symbiosis‐related polypeptides during the early stages of the establishment of arbuscular mycorrhiza between Glomus mosseae and Pisum sativum roots

“…Interestingly, the AM-resistant myc" genotype showed a different pattern. During the time of infection, an increase was obvious for some low MW polypeptides called Pi (16,19,23, biosis are associated with modifications in gene expression in both symbionts (Dumas et al, 1989;Dumas-Gaudot et al, 19946;Gianinazzi-Pearson et al, 1994;Gianinazzi et al, 1995;GianinazziPearson, 1995;Kapulnike^a/., 1996;Murphy et al, 1997). Accumulation of additional polypeptides has already been reported in AM roots of several plants (Dumas et al, 1989;Wyss et al, 1990;Arines et al, 1993;Garcia-Garrido et al, 1993;Dumas-Gaudot et al, 19946;Simoneau et al, 1994).…”

“…Investigations on gene regulation in endomycorrhiza were first focused on genes implicated in plant defence response (Harrison & Dixon, 1993;Volpin et al,1995;Blee & Anderson, 1996;Kapulnik et al, 1996). A phosphate transporter gene (Harrison & van Buuren, 1995) and a gene homologous to H*-ATPase (Murphy, Langridge & Smith, 1997) were proved to be upregulated in AM symbiosis. Transcriptional activation of a-tubulin gene also occurred in mycorrhizal maize and transgenic tobacco plants symbiosis with AM fungi but are unable to form (Bonfante et al, 1996).…”

A Mycorrhizal-Specific Ammonium Transporter from Lotus japonicus Acquires Nitrogen Released by Arbuscular Mycorrhizal Fungi

“…We suggest that, together with the protons, which are actively transported into the interfacial apoplast by the plant and also by fungal H + -ATPases (Murphy et al, 1997;Gianinazzi-Pearson et al, 2000;Krajinski et al, 2002;Requena et al, 2003;Balestrini et al, 2007), the protons coming from the NH 4 + deprotonation process remain in the interface space and maintain or even reinforce the gradient for H + -dependent transport processes (Fig. 9).…”

Plant Cell Responses to Arbuscular Mycorrhizal Fungi: Getting to the Roots of the Symbiosis

“…There is evidence that root plasma membrane H+-ATPase genes are upregulated during AM interactions. In barley, AM development is accompanied by increased levels of transcripts hybridizing to an H+-ATPase homologous cDNA clone (Murphy et al, 1996), and promoter-GUS fusion assays in tobacco indicate that at least two H+-ATPase genes are activated in arbusculecontaining cells (V. Gianinazzi-Pearson, L. Moriau, and M.…”