Study On Diversity Analysis Of Polysaccharide And Proteomics Of Chinese Wolfberry (Lycium Barbarum) Fruits During Different Development Periods

Fruit ripening is a complex process regulated by both genetic and epigenetic factors,in addition to objective factors.The previous studies on the development of wolfberry fruits mainly focused on the effect of environmental factors on the formation of fruit quality,the accumulation of nutrients in the development process,etc.Studies on the proteomics of fruit development and maturation have not been reported.The production of polysaccharides of the active ingredient and the process of transport and storage in the plant are not yet clear.In order to study the regulation mechanism of polysaccharide accumulation during Lycium barbarum maturation process,the characteristics of the polysaccharides were studied using the fruit of loquat fruit at different developmental stages.At the same time,iTRAQ technology was applied to study the dynamic changes of protein in loquat during the ripening process.The specific findings are as follows:1)Extraction and purification of polysaccharides from different maturity levels of Lycium barbarum,and analysis of related physical and chemical indicators.As a result,it was found that the polysaccharide content of loquat fruits varied with the growth and development stages.The accumulation of polysaccharides in the early yellow and full fruit period,the lowest polysaccharide content in the green fruit period and significant difference with the polysaccharide content of other fruit periods(p<0.05),There was a significant difference between the polysaccharides in the early yellowing and full fruiting period and other fruits(p<0.01).The content of uronic acid in fruits showed a trend of first increase and then decrease,and there was a very significant difference in the fruit period of young fruit stage,young fruit stage,early yellowing stage,late yellowing stage and full fruit stage(p<0.01).The content of soluble protein showed a slow increase and then decreased.At the late yellowing stage,the soluble protein content was highest in loquat fruit.After an anion exchange column,it was judged that the polysaccharide was an proteoglycan.With the development of earthworms,wolfberry polysaccharides are gradually converted from neutral sugars to acidic sugars.2)The structural characteristics of polysaccharides were studied at different developmental stages.The molecular weights of LBP2 in different periods were mainly distributed at 6-40 KDa.LBP2 is mainly composed of six monosaccharides such as arabinose,rhamnose,glucose,xylose,mannose,and galactose.Infrared spectroscopy shows that LBP2 is an acidic polysaccharide with a sugar ring conformation in the form of a ?-pyran ring.The thermal properties of the five polysaccharides were similar by the results of the TG-DSC curves of polysaccharides from Lycium barbarum.There are two stages in the thermal decomposition process.The first stage is the removal of water of crystallization,and the second stage is oxidation and decomposition.Macromolecular skeleton of polysaccharide were fractured.Scanning electron microscopy(SEM)was used to observe the surface morphology of Lycium barbarum polysaccharides.It was found that Lycium barbarum polysaccharides were all lamellar structures formed by aggregating spherical structures,but they had different surface morphology at different developmental stages.3)iTRAQ was used to determine the differentially expressed proteins in mature fruits of loquat fruits at different developmental stages.The BCA method was used to quantitate the protein in each stage of pupa,SDS-PAGE was used to measure the quality of protein samples,and the iTRAQ-labeled samples were analyzed by mass spectrometry.The iTRAQ-labeled samples were analyzed by mass spectrometry.The results showed that 3910 proteins were identified from the 5 samples.The relative molecular masses of the identified proteins were mainly distributed between 10 and 70 KDa,and the protein intermediate electrical points were 6 and 7 at most The proportion of peptides with a peptide length of 9 to 11 amino acids is the highest,and most of the proteins contain no more than 20 peptides.The differential protein identification results showed that 1,799 different proteins were identified in five developmental stages.With the development and maturation of earthworms,the number of differential proteins also gradually increased.Compared with pupa proteins in the young fruit stage,the number of up-regulated proteins was higher than that of down-regulated proteins in the late fruiting,yellowing,and late yellowing stages.The clustering results showed that the expression patterns of the protein in different developmental stages were divided into two types.The fruit expression pattern was similar in the early flowering young fruit stage,the green fruit stage and the early yellowing period,and the fruit expression patterns were similar in the late yellowing and full fruiting period.4)The GO annotation was performed on all the identified proteins.The results showed that the differential proteins identified during maturation were mainly distributed in cells and intracellular organs.The proteins with catalytic activity and binding activity were the main ones,and the main biological processes involved were.Related to cells and metabolic processes.The results of GO enrichment during the maturation process showed that the differences mainly focused on photosynthesis,energy metabolism,sugar metabolism,oxidation and reduction and metabolic processes.A total of 203 proteins were screened for proteins that were related to polysaccharide metabolism under different developmental stages.