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.
2021-01-31 | GSE159700 | GEO
Project description:Niche Differentiation of Three Terrestrial Isopod Species Based on DNA Metabarcoding
| PRJNA1236731 | ENA
Project description:Transcriptome data of three orchid species flowers
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.
Project description:Mycorrhizal fungi colonize orchid seed and induce the germination. This so-called symbiotic germination is a critical developmental process in the lifecycle of all orchids. However, the molecular changes taking place during the orchid seed symbiotic germination still remains largely unknown. To better understand the molecular mechanism of orchid seed germination, we performed comparative transcriptomic and proteomic analysis on Chinese traditional medicinal orchid plants, Dendrobium officinale to explore protein expression change at the different developmental stages between asymbiotic and symbiotic germination and identify the key proteins regulated symbiotic germination of orchid seeds. iTRAQ analysis from 8 samples identified 2256 plant proteins, of which, 308 proteins were differentially expressed across three developmental stages within asymbiotic or symbiotic accession and 229 proteins are differentially expressed in the symbiotic germination compared to asymbiotic germination. 32 proteins are co-upregulated in both proteomic and transcriptomic level for symbiotic germination compared to asymbiotic germination. Our results revealed that symbiotic germination of D. officinale seeds probably shares the common signal pathway with asymbiotic germination during the early germination stage.
Project description:To compare the similarities and differences in species diversity of the gut microbiota between the patients with melasma and healthy subjects. The feces were collected for 16S rRNA sequencing analysis of the gut microbiota.
