Search results for "Spore"
showing 10 items of 252 documents
Bacterial rhamnolipids are novel MAMPs conferring resistance to Botrytis cinerea in grapevine
2009
International audience; Rhamnolipids produced by the bacteria Pseudomonas aeruginosa are known as very efficient biosurfactant molecules. They are used for a wide range of industrial applications, especially in food, cosmetics and pharmaceutical formulations as well as in bioremediation of pollutants. In this paper, the role of rhamnolipids as novel molecules triggering defence responses and protection against the fungus Botrytis cinerea in grapevine is presented. The effect of rhamnolipids was assessed in grapevine using cell suspension cultures and vitro-plantlets. Ca2+ influx, mitogen-activated protein kinase activation and reactive oxygen species production form part of early signalling…
An STE12 gene identified in the mycorrhizal fungus Glomus intraradices restores infectivity of a hemibiotrophic plant pathogen
2009
International audience; * • Mechanisms of root penetration by arbuscular mycorrhizal (AM) fungi are unknown and investigations are hampered by the lack of transformation systems for these unculturable obligate biotrophs. Early steps of host infection by hemibiotrophic fungal phytopathogens, sharing common features with those of AM fungal colonization, depend on the transcription factor STE12. * • Using degenerated primers and rapid amplification of cDNA ends, we isolated the full-length cDNA of an STE12-like gene, GintSTE, from Glomus intraradices and profiled GintSTE expression by real-time and in situ RT-PCR. GintSTE activity and function were investigated by heterologous complementation …
Symbiosis-related plant genes modulate molecular responses in an arbuscular mycorrhizal fungus during early root interactions.
2009
To gain further insight into the role of the plant genome in arbuscular mycorrhiza (AM) establishment, we investigated whether symbiosis-related plant genes affect fungal gene expression in germinating spores and at the appressoria stage of root interactions. Glomus intraradices genes were identified in expressed sequence tag libraries of mycorrhizal Medicago truncatula roots by in silico expression analyses. Transcripts of a subset of genes, with predicted functions in transcription, protein synthesis, primary or secondary metabolism, or of unknown function, were monitored in spores and germinating spores and during interactions with roots of wild-type or mycorrhiza-defective (Myc–) mutan…
Rediscovery of Riella alatospora (Riellaceae, Sphaerocarpales), an aquatic, South African endemic liverwort previously known from a now largely trans…
2012
7 páginas, 4 figuras.
Morphological traits predict host-tree specialization in wood-inhabiting fungal communities
2020
Tree species is one of the most important determinants of wood-inhabiting fungal community composition, yet its relationship with fungal reproductive and dispersal traits remains poorly understood. We studied fungal communities (total of 657 species) inhabiting broadleaved and coniferous dead wood (total of 192 logs) in 12 semi-natural boreal forests. We utilized a trait-based hierarchical joint species distribution model to examine how the relationship between dead wood quality and species occurrence correlates with reproductive and dispersal morphological traits. Broadleaved trees had higher species richness than conifers, due to discomycetoids and pyrenomycetoids specializing in them. Re…
Stomatal deregulation in Plasmopara viticola-infected grapevine leaves.
2007
International audience; In grapevine, the penetration and sporulation of Plasmopara viticola occur via stomata, suggesting functional relationships between guard cells and the pathogen. This assumption was supported by our first observation that grapevine (Vitis vinifera cv. Marselan) cuttings infected by P. viticola wilted more rapidly than healthy ones when submitted to water starvation. • Here, complementary approaches measuring stomatal conductance and infrared thermographic and microscopic observations were used to investigate stomatal opening/closure in response to infection. • In infected leaves, stomata remained open in darkness and during water stress, leading to increased transpir…
Food stoichiometry affects the outcome of Daphnia–parasite interaction
2013
Phosphorus (P) is an essential nutrient for growth in consumers. P-limitation and parasite infection comprise one of the most common stressor pairs consumers confront in nature. We conducted a life-table study using a Daphnia–microsporidian parasite model, feeding uninfected or infected Daphnia with either P-sufficient or P-limited algae, and assessed the impact of the two stressors on life-history traits of the host. Both infection and P-limitation negatively affected some life-history traits tested. However, under P-limitation, infected animals had higher juvenile growth rate as compared with uninfected animals. All P-limited individuals died before maturation, regardless of infection. Th…
Influence of leaf age on induced resistance in grapevine against Plasmopara viticola
2012
International audience; Sulfated laminarin (PS3) has previously been shown to induce resistance of grapevine leaves against the oomycete Plasmopara viticola, the causal agent of grape downy mildew. Here, we observed that the level of PS3-induced resistance (PS3-IR) was higher in the adult leaf (in position P3) than in the younger, not fully expanded leaf (in position P1, located above P3). By investigating grapevine defense reactions upon PS3 treatment and inoculation, we found that the production of H2O2, of phytoalexins, and the deposition of phenolics were more abundant in P3 than in P1 leaves. In addition, PS3 significantly reduced stomatal colonization by zoospores only in P3 leaves. T…
Cucumispora dikerogammari n. gen. (Fungi: Microsporidia) infecting the invasive amphipod Dikerogammarus villosus: a potential emerging disease in Eur…
2010
SUMMARYDikerogammarus villosusis an invasive amphipod that recently colonized the main rivers of Central and Western Europe. Two frequent microsporidian parasites were previously detected in this species, but their taxonomic status was unclear. Here we present ultrastructural and molecular data indicating that these two parasites are in fact a single microsporidian species. This parasite shares numerous characteristics ofNosemaspp. It forms elongate spores (cucumiform), developing in direct contact with host cell cytoplasm; all developmental stages are diplokaryotic and the life cycle is monomorphic with disporoblastic sporogony. Initially this parasite was described asNosema dikerogammariO…
The mycorrhizal soil infectivity and arbuscular mycorrhizal fungal spore communities in soils of different aged fallows in Senegal
2001
This work was carried out to determine the influence of the duration of fallow and of physico-chemical components of soils on the distribution of endomycorrhizal fungal spores and the mycorrhizal soil infectivity. The mycorrhization of indigenous plants from the fallows was examined and it was concluded that, except for Cassia obtusifolia, fungal colonization was poorly developed. No correlation was established between spore populations and duration of fallow or between grazed and fenced areas. The relationships between abundance of mycorrhizal spores and the physico-chemical characteristics of the soils were markedly variable among species of mycorrhizal fungi. The results did not provide …