Physiological And Quantitative Proteomics Analysis Of Chilling Injury Of The Straw Mushroom(Volvariella Volvacea)

The straw mushroom(Volvariella volvacea)is a high-temperature edible fungus growing in tropical and subtropical regions,which is sensitive to temperature and more likely to have chilling injury,leads to reducing commodity value.In this paper,symptoms of the straw mushroom chilling injury and quality change were learnt via the determination of physiological index for the straw mushroom at different storage temperature.Moreover,analysed the change in protein of the straw mushroom before and after chiling injury via proteomics approach,speculated the relationship between differentially expressed proteins and chilling injury of the straw mushroom.Not only provided the basis for the study of the molecular mechanisms of the straw mushroom response to abiotic stress,but also provided a theoretical basis for the straw mushroom storageThe main research contents and results are as follows:The effects of different storage temperatures on the physiological and biochemical indexes,such as respiration intensity,weight loss rate,soluble sugar content,soluble protein content,SOD and CAT of the straw mushrooms were studied.The experimental results showed that compared with the control group,the storage conditions of 16 ℃ can avoid the occurrence of chilling injury,reduce the respiratory intensity and weightlloss rate,slow down the loss of nutrients,maintain high SOD and CAT activity,and have obvious fresh-keeping effect.The straw mushrooms stored at 4 ℃ and 10 ℃ showed symptoms of chilling injury at 6 h,the respiratory intensity increased abnormally,the weight loss rate was increased rapidly,the soluble sugar content and soluble protein content were relatively high,SOD increased rapidly,CAT decreased rapidly,and lost their commodity value after 24 hours.332 differential proteins were identified via proteomics approach,including 64 up-regulated and 268 down-regulated differential proteins.GO enrichment analysis showed that the differential proteins were mainly distributed in the cell part,mainly involved in cellular processes and metabolic processes,mainly related to molecular functions such as binding and catalytic activity.KEGG analysis showed that differential proteins were enriched in 57 KEGG metabolic pathways.COG analysis showed that 328 differential proteins were annotated and divided into 22 COG functions.These differential proteins are mainly related to glycolysis,tricarboxylic acid cycle,pentose phosphate pathway,respiratory chain,ATP synthesis,protein metabolism,protein biosynthesis,active oxygen metabolism,cell wall material metabolism,trehalose metabolism,signal transduction mechanisms,membrane lipids metabolism and Heat shock protein.Using q PCR technology to verify glyceraldehyde-3-phosphate dehydrogenase and NADH-ubiquinoneoxidoreductase,the results showed that the transcriptional expression of these two enzymes was consistent with the protein level,but the proteomics data still need to be further verified.Based on the results of physiological and biochemical indicators and differential proteomics,it is speculated that the chilling injury of straw mushrooms has the following characteristics:(1)Disturbance of energy metabolism.(2)Membrane lipids metabolism is disturbed.(3)Active oxygen metabolism is disturbed.(4)Protein function is disturbed.(5)Straw mushroom fruiting body texture becomes soft.(6)Cold resistance decreases.These results will provide new clues for further research on the chilling injury mechanism of straw mushroom.