Project description:Root-microbe interaction and its specialized root nodule structures and functions are well studied. In contrast, leaf nodules harboring microbial endophytes in special glandular leaf structures have only recently gained increased interest as plant-microbe phyllosphere interactions. Here, we applied a comprehensive metabolomics platform in combination with natural product isolation and characterization to dissect leaf and leaf nodule metabolism and functions in <i>Ardisia crenata</i> (Primulaceae) and <i>Psychotria punctata</i> (Rubiaceae). The results indicate that abiotic stress resilience plays an important part within the leaf nodule symbiosis of both species. Both species showed metabolic signatures of enhanced nitrogen assimilation/dissimilation pattern and increased polyamine levels in nodules compared to leaf lamina tissue potentially involved in senescence processes and photosynthesis. Multiple links to cytokinin and REDOX-active pathways were found. Our results further demonstrate that secondary metabolite production by endophytes is a key feature of this symbiotic system. Multiple anhydromuropeptides (AhMP) and their derivatives were identified as highly characteristic biomarkers for nodulation within both species. A novel epicatechin derivative was structurally elucidated with NMR and shown to be enriched within the leaf nodules of <i>A. crenata</i>. This enrichment within nodulated tissues was also observed for catechin and other flavonoids indicating that flavonoid metabolism may play an important role for leaf nodule symbiosis of <i>A. crenata.</i> In contrast, pavettamine was only detected in <i>P. punctata</i> and showed no nodule specific enrichment but a developmental effect. Further natural products were detected, including three putative unknown depsipeptide structures in <i>A. crenata</i> leaf nodules. The analysis presents a first metabolomics reference data set for the intimate interaction of microbes and plants in leaf nodules, reveals novel metabolic processes of plant-microbe interaction as well as the potential of natural product discovery in these systems.
Project description:The leaf transcriptome of the nickel hyperaccumulator species Psychotria grandis and Psychotria costivenia (Rubiaceae) from Cuba were compared to the closely related non-accumulator Psychotria revoluta, living on Gallery forest on serpentine soil, to identity differentially expressed genes potentially involved in Ni hyperaccumulation.
Project description:The leaf transcriptome of the nickel hyperaccumulator Geissois pruinosa (Rubiaceae) endemic from New Caledonia was compared to the closely related non-accumulator Geissois racemosa, living respectively in serpentine maquis or rainforest on limestone, to identity differentially expressed genes potentially involved in Ni hyperaccumulation.
Project description:Leaf-cutting ants of the genera Acromyrmex and Atta live in mutualistic symbiosis with a basidiomycete fungus (Leucocoprinus gongylophorus), which they cultivate as fungal gardens in underground nest chambers. The ants provide the fungus with a growth substrate consisting of freshly cut leaf fragments. After new leaf fragments are brought into the nest, the ants chew them into smaller pieces and apply droplets of fecal fluid to the leaf pulp before depositing this mixed substrate in the fungus garden and inoculating it with small tufts of mycelium from older parts of the garden. Previous work has shown that the fecal fluid contains a range of digestive enzymes including proteases, amylases, chitinases, cellulases, pectinases, hemicellulases and laccases, and that most of these enzymes are produced by the fungal symbiont in specialized structures called gongylidia that the ants eat. After ingestion, the enzymes apparently pass unharmed through the alimentary channel of the ants and end up in the fecal fluid. Most likely this complex system is an adaptation of the ant-fungus symbiosis to a herbivorous lifestyle, as the ancient ancestors of the ants and the fungus lived as hunter-gatherers and saprotrophs, respectively. The promise of fecal fluid for getting insight into the molecular adaptations that enables the ant-fungus holosymbiont to live as a herbivore, led us to investigate the fecal fluid proteome using LC-MS/MS in order to get a more comprehensive picture of the repertoire of proteins present.
Project description:The leaf transcriptome of the nickel hyperaccumulator Psychotria gabriellae (Rubiaceae) endemic from New Caledonia was compared to the closely related non-accumulator Psychotria semperflorens, living in sympatry with P. gabriellae in rain forest on serpentine soil, to identity differentially expressed genes potentially involved in Ni hyperaccumulation.
Project description:affy_ams_maize - aafy_ams_maize - Main objectives of this study: - role of plant cell wall during AM symbiosis - regulation pattern during AM symbiosis - understanding of the original mycorrhizal phenotype of bm4 - search of candidate-genes to study AM symbiosis-After 7 days in phytochambers, plantlets were transplanted in 2L of humidified bedrock with 3000 spores for inoculation conditions or without spore for mock conditions then plants have grown in greenhouse. Maize roots have been sampled 7 weeks post-inoculation and freezed in liquid nitrogen then stocked at -80M-BM-0C. Total RNA was isolated from frozen root tissue by using the RNeasy Plant Mini Kit (Qiagen) following the manufacturerM-bM-^@M-^Ys instructions. Keywords: treated vs untreated comparison 8 arrays - maize
Project description:affy_ams_maize - aafy_ams_maize - Main objectives of this study: - role of plant cell wall during AM symbiosis - regulation pattern during AM symbiosis - understanding of the original mycorrhizal phenotype of bm4 - search of candidate-genes to study AM symbiosis-After 7 days in phytochambers, plantlets were transplanted in 2L of humidified bedrock with 3000 spores for inoculation conditions or without spore for mock conditions then plants have grown in greenhouse. Maize roots have been sampled 7 weeks post-inoculation and freezed in liquid nitrogen then stocked at -80°C. Total RNA was isolated from frozen root tissue by using the RNeasy Plant Mini Kit (Qiagen) following the manufacturer’s instructions. Keywords: treated vs untreated comparison
Project description:The mutualistic arbuscular mycorrhizal (AM) symbiosis arose in land plants more than 450 million years ago. This symbiosis is still widely found across major land plant lineages, including bryophytes. Despite its broad taxonomic distribution, little is known about the molecular components underpinning symbiosis outside of flowering plants. Here, we demonstrate that a broad AM genetic programme is conserved amongst land plants. In this study, we characterised the dynamic response of the liverwort Marchantia paleacea to Rhizophagus irregularis colonization by time-resolved transcriptomics across three stages of symbiosis. Comparative analysis of transcriptional responses to symbiosis in the liverwort M. paleacea and the legume Medicago truncatula further revealed evolutionarily conserved expression patterns for genes underpinning pre-symbiotic signalling, intracellular colonization and nutrient exchange. This study demonstrates that the genetic machinery regulating key aspects of symbiosis in plant hosts is largely conserved and coregulated across land plants.