Project description:The study of orchid mycorrhizal interactions is particularly complex because of the peculiar life cycle of these plants and their diverse trophic strategies. Here, large-scale transcriptomics has been applied to investigate gene expression in the mycorrhizal roots of the terrestrial mixotrophic orchid Limodorum abortivum under natural conditions. Our results provide new insights into the mechanisms underlying plant-fungus interactions in orchids and in particular on the plant responses to the mycorrhizal symbiont(s) in adult roots. Comparison with gene expression in mycorrhizal roots of another orchid species, Oeceoclades maculata, suggests that amino acids may represent the main nitrogen source in both protocorms and adult orchids, at least for mixotrophic species. The upregulation, in mycorrhizal L. abortivum roots, of some symbiotic molecular marker genes identified in mycorrhizal roots from other orchids as well as in arbuscular mycorrhiza, suggests a common plant core of genes in endomycorrhizal symbioses. Further efforts will be required to understand whether the specificities of orchid mycorrhiza depend on fine-tuned regulation of these common components, or whether specific additional genes are involved.
Project description:Local genetic adaptation in wild chimpanzees: Evidence from Cameroon
| PRJNA1092604 | ENA
Project description:SLAF-seq based genetic diversity and structure of geodorum eulophioides, an endangered terrestrial orchid species with extremely small populations in China.
Project description:Plants display remarkable developmental and phenotypic plasticity in order to adapt to their environment. It has long been postulated that epigenetics plays a key role in these processes, but with one or two exceptions, solid evidence for the role of epigenetic variation in these processes is lacking. A key impediment to understanding these processes is the lack of information on the extent of epigenetic variation and how it relates to genetic and phenotypic variation in natural population, both over the lifecycle of an individual, and over evolutionary time. Here we show that genetic variants under selection in the north of Sweden appear to drive variation in DNA methylation, which in turn is highly correlated with local climate. Selective sweeps and genetic variants associated with adaptation to the local environment have previously been identified within the Swedish Arabidopsis population. Our finding that they harbour variants responsible for climate associated epigenetic variation strongly supports the role of epigenetic processes in local adaptation. These findings provide a basis for further dissecting the role of epigenetics in local adaptation at the molecular level Bisulfite sequencing of 113 F2 crosses between T550 and Brosarp-11-135.
Project description:Orchids form an endomycorrhizal association with fungal symbionts mainly belonging to Basidiomycetes. The molecular events taking place in orchid mycorrhiza are poorly understood, although the cellular changes necessary to accommodate the fungus and to control nutrient exchange between the symbionts imply a modulation of gene expression. In this study, we used proteomic and transcriptomic approaches to identify changes in the steady-state levels of proteins and transcripts in roots of the green terrestrial orchid Oeceoclades maculata. When mycorrhizal and non-mycorrhizal roots from the same individuals of O. maculata were compared, 94 proteins showed differential accumulation using the label-free protein quantitation approach, 86 using isobaric tagging (iTRAQ) and 60 using 2D-differential electrophoresis. After de novo assembly of transcriptomic data, 11,179 plant transcripts were found to be differentially expressed and 2175 were successfully annotated. The annotated plant transcripts allowed the identification of up- and down-regulated metabolic pathways in mycorrhizal roots, as compared to non-mycorrhizal roots. Overall, proteomics and transcriptomics revealed in mycorrhizal roots increased levels of transcription factors and nutrient transporters, as well as ethylene-related proteins. The expression pattern of proteins and transcripts involved in plant defense responses suggest that plant defense is reduced in mycorrhizal roots. These results expand our current knowledge towards a better understanding of the orchid mycorrhizal symbiosis in adult plants under natural conditions.