Metabolomics Analysis Of Rice (Oryza Sativa L.) In Main Production Area Of Heilongjiang Province Based On GC-MS Technology

Rice is one of the main food crops in China.The improvement of living standards has led people to focus on the flavor and nutritional quality of rice.Geographical indication rice products are representative products with distinctive characteristics in the rice market.Therefore,it is favored,and its quality and beauty are mainly determined by the characteristics of the planting area.Metabolomics is widely used and will be a good analytical platform for the identification and differentiation of agricultural products.Therefore,metabolomics research on geographical indication rice from different producing areas can provide a theoretical basis for the identification and differentiation of rice production areas,and provide new ideas for the establishment of rice origin traceability system.This subject was based on the metabolomics technology of gas chromatography and mass spectrometry(GC-MS).Multivariate statistical analysis,included principal component analysis(PCA)and orthogonal partial least squares discriminant analysis(OPLS-DA)And methods such as cluster analysis and metabolic pathway analysis.Taked 280 rice seeds from the four main producing areas of Wuchang,Ning'an,Jiansanjiang and Chahayang in Heilongjiang Province as the research object.To explored the significant effects of variety and origin on the differences in rice metabolism.Metabolomics analyzed and screened of differential metabolites for rice from different producing areas.The effects of storage time and year on rice metabolism and quality were studied,and the differences among rice seeds from different producing areas were further visualized.The study mainly got the following results and conclusions:(1)Explored the significant effects of variety and origin on the differences in rice metabolism(70 samples).Discriminant analysis by orthogonal partial least squares method showed that the rice samples of the same variety in different producing areas were significantly different.There was no significant difference in rice samples from different varieties in the same producing area.There were also differences between rice samples of the same variety.The composition or content of rice samples of different varieties in the same producing area had similarities.It is indicate that the significant effect of the place of origin on rice metabolism is greater than the significance of the variety on rice metabolism.(2)Metabolomics analyzed and screened of differential metabolites for rice from different producing areas(120 samples).The results showed that the four producing areas of Wuchang,Ning'an,Jiansanjiang and Chahayang were compared with other producing areas except themselves.Wuchang,Ning'an,Jiansanjiang and Chahayang screened 24,12,26 and 30 differential metabolites,respectively.Metabolic pathway analysis of the selected differential metabolites.It was indicated that the metabolic pathways involved in differential metabolites were mostly fatty acid metabolism,sugar metabolism and sterol metabolism.Explained that the place of origin had an important impact on the lipids and sugars in rice.The differential metabolites screened by each group were almost different and can be used as the basis for identification and differentiation of different rice producing areas.Simultaneous comparative analysis of rice samples from four producing areas.Found that there were 55 metabolites in the four producing areas,40 differential metabolites were screened.The preliminary application of the applied rice identification model was carried out.With OPLS-DA as the modeling method,an intuitive and rapid application-type rice identification and differentiation model was established.Model verification was carried out with rice samples from the same origin and commercially available rice samples.The comprehensive accuracy rate is 90%,indicating that the established model has good applicability.(3)Explored the effects of storage time on rice metabolism(60 samples).The rice samples from 2015 were compared with the 2015 rice samples stored one year after storage.It was found that the amount of metabolites,the content of each metabolite,and the proportion of various metabolites changed.The trend of content change was reverse change,that is,high to low,low to high,Among them,fatty acids,amino acids and sugars were more significant.(4)To explored the effects of different years on rice metabolism(60 samples).Comparative analysis of rice samples from 2015 and 2017.It was found that the amount of metabolites,the content of each metabolite,and the proportion of various metabolites in rice seeds in different years would change.But this change was small.Explain that different years have an impact on rice quality.But the magnitude of the change is small.In summary,the metabolomics based on GC-MS is feasible for the identification and differentiation of geographical indication rice.Metabolomics can visually study the effects of various factors on rice growth and rice circulation from the perspective of endogenous metabolites in rice seeds.Metabolomics can visualize the effects of various factors on rice growth and rice circulation from the perspective of endogenous metabolites in rice seeds.From the perspective of metabolomics,the effects of factors such as origin,storage time and year on rice metabolism were analyzed to provide a theoretical basis for exploring the correlation between different factors and rice quality.