Proteomic Analysis Of Drought Tolerance Mechanism In Umbilicaria Muhiengergii

Lichens, as an united symbiotic ecosystem, are usually composed by a symbiotic fungus with one or more of the photosynthetic alga. Lichenization can enhance the resistance of the lichen fungi, which makes lichens become one of the strongest resistance biology in the world. Many metabolites of lichen have various biological activities, such as anti-cancer, anti-microbe, anti-inflammation, anti-oxidant and so on. But the molecular mechanism underlying stress tolerance is still unknown. In order to reveal the resistance mechanisms of lichens, this research used PEG6000 to induce Umbilicaria muehlenbergii by drought, and then made use of the proteome technology and mass spectrometry to study the molecular mechanism of resistence of drought of the Umbilicaria muehlenbergii on proteomics level.First of all, we optimized the method for the preparation of Umbilicaria muehlenbergii protein, and purified the protein samples suitable for 2-Dimensional Electrophoresis. Then, we identified 136 proteins whose abundance were changed by twice fold under PEG6000-induced stress. By querying the database, we analysed the isoelectric point, relative molecular mass, intracellular location and function of the identified proteins, and then finds that most of the identified proteins are related to mitochondria, molecular chaperone and ribosomes, which indicated that Umbilicaria muehlenbergii could regulate the energy metabolism, protein synthesis and folding process to adapt to the drought stress. Further physiological experiment results showed that under the PEG6000-induced stress, the growth rate of Umbilicaria muehlenbergii slowed down and the mitochondrial activity decreased, which is consistent with the proteomics research results.This study at the proteomics level will contribute to elucidading the drought-resistence molecular mechanism of the lichen.