| Dendrobium symbiotic mycorrhzae refers to mycorrhizal associations in the Dendrobium roots cell. Between harmful or beneficial fungus and roots occurrs coevolution around the Dendrobium base area. Plant has an adaptive mechanism against the fungal infection, and forms a mycorrhizal association to adapt to the complex ecological environment changes. In the long-term of direct or indirect contact of plants and fungus, fungus infected and colonized in Dendrobium roots has built a mutually beneficial relationship. The specific functional structures formed in the root of Dendrobium nobile promote the plant growth and development and medicinal ingredients accumulation. In this process, fungus’molecule mechanism changes and induces the genes of Dendrobium to change relevantly. So far, the researches about Dendrobium symbiotic mycorrhzae mostly focus on morphogenesis, effect of host plants’biomass and effective ingredients,without researching into basic molecule mechanism. So, based on the association system of Dendrobium-fungus, this study conducts a preliminary analysis of the molecular mechanism of interaction between them from the perspective of fungi.Firstly, using the mycorrhzae symbiotic system of Dendrobium nobile-Mycena dendrobii built by our lab, the high-throughput sequencing technology was employed to analyse the gene expression profiling of Mycena dendrobii whose genome is unknown. Using Illlumina sequencing technology, we detect the number of the total changged unigenes of Mycena dendrobii is65535after Infecting nobile Dendrobium, which up-regulated40594, down-regulated24941. Unigene65712, Unigene65407, Unigene68656etc.up-regulated15times or more, which play an important part in the biosynthesis of Cl-channel protein, auxin efflux carrier transmembrane protein and peptide synthetase. Maybe these genes involved in the establishment of Dendrobium mycorrhizal process, their functions will be subject to further research.At the same time, the symbiosis of a Rhizoctonia isolated from wild Dendrobium by our laboratory was researched. Microscopic observation found, the fungi began to invade the periderm cells of Dendrobium roots in10days, and invade the column in30days. Thus, we establish the mycorrhizal symbiosis system beteen Rhizoctonia and Dendrobium nobile. Further statistical analysis revealed that the symbiotic system can promote the biomass accumulation of Dendrobium nobile tissue culture.Then, we refer to the changed genes of Mycena transcriptome to quantitatively analyze the changes of the corresponding genes in Rhizoctonia. The result found that the several gene expressions of Rhizoctonia are also significantly up-regulated, such as18S,28S,5.8S,25S ribosomal RNA gene, translation elongation factor (TEF) gene. They may be involved in the process of building mycorrhizal. In future studies, we will have a more in-depth demonstration about these genes’ function. |
