Temperature Influences The Differential Expression Of Intracellular And Extracellular Proteins Of Edible Fungus Pleurotus Tuber-regium (Fr.) Sing

Autolysis phenomena exist widely in a variety of microbes.However,the mycelium autolysis of the edible and medical Pleurotus tuber-regium(Fr.) has not been reported at home and abroad.This experiment initiated from screening the appropriate conditions of Pleurotus tuber-regium(Fr.) mycelium autolysis,then treating the mycelium with the optimal autolysis condition,and finally analyzing the autolysis by using differential proteomic method.First,the effects of different temperature,pH and osmotic pressure on mycelium autolysis were studied via liquid fermentation of Pleurotus tuber-regium(Fr.) mycelium.The results showed that the appropriate monofactorial condition of autolysis is temperature 40℃,pH 9.0 and NaCl concentration 3-4%.Then,an efficient method for extracting the total proteins from the Pleurotus tuber-regium(Fr.) mycelium was established with high resolution applicable to the proteomic 2-D electrophoresis analysis.The results indicated that the TCA/acetone method was optimal for extracting total protein for 2-D electrophoresis.The method of extracting extracellular protein was also obtained in this research.Lastly,the autolysis of Pleurotus tuber-regium(Fr.) mycelium was investigated by differential proteomics,using 40℃treatment as experimental group and 10℃as control.Twenty-two protein spots with remarkable up-regulation were obtained for analysis by MALDI-TOF/MS and PMF,and eight proteins were identified.Of these proteins,proteasome participates in ubiquitin-proteasome pathway;β-1,3-glucanosyltransferase and tubulin are involved in the renew and repair of cell wall;protease and endo-glucanase promote the natural degradation of cell wall and cytoplasm;and 14-3-3 protein deals with cell signal transduction.Thus,the process of Pleurotus tuber-regium(Fr.) mycelium autolysis is presumed as follows:under nutrition shortage or high temperature treatment,the cells undergo metabolic malfunction and inner structure disruption;then the proteasome degrades the intracellular proteins and leads to the release of hydrolases such as prolease and endo-glucanase to accelerate cell wall and cytoplasm degradation;the autolysis products serve as the nutrition for the progeny;and theβ-1,3-glucanosyltransferase and tubulin maintain the normal cell shape and function by renewing and repairing cell wall.