Spatio-temporal Distribution And Natural Variation Of Metabolites In Citrus Fruits

Metabolites in citrus are important sources of vitamin for human and many metabolites have medicinal values that play an important role to human health. To study the natural variation and spatio-temporal accumulation of citrus metabolites, liquid chromatography tandem mass spectrometry(LC–MS) based metabolome analysis was performed on four fruit tissues(flavedo, albedo, segment membrane and juice sacs) and different Citrus species(lemon, pummelo and grapefruit, sweet orange and mandarin) in 47 citrus family. The main results were as follows:1. In liquid chromatography and mass spectrometry technology strategy, we use the targeted metabolite detection in 47 family different parts and different types of mixed samples and extract the metabolites, in citrus mix samples we got more than 2000 metabolites signals at the same time use the method of standard that 54 metabolites were identified. These metabolites including amino acids, flavonoids and limonin. For the analysis of metabolites in different groups and the difference of the accumulation in the line of our target identification of 54 kinds of metabolites in 47 on targeted in the line of the metabolites of detection.2. Through principal component analysis(PCA), we can see obviously citrus four types and organization are separate, in different parts of the citrus and metabolite accumulation in different organizations have an obvious specificity. In different parts of flavonoids in flavedo has an obvious accumulation, and in the juice sacs is of specific amino acids matter accumulation. For different types of citrus, has the useful value of limonin in lemon contains a specific class matter accumulation, and the characteristics of such matter has a bitter taste, affecting citrus economic value in the cultivated varieties.3. Based on types and levels of metabolites index clustering analysis found that the 47 citrus family obviously divided into lemon, pummelo and grapefruit, sweet orange and mandarin, and hierarchical clustering analysis and the neighbor-joining tree shows that several of pummelo class family obviously different from the rest of the three types. Before the analysis of citrus genome sequencing results shows that the orange may be comes from as the grapefruit subspecies as maternal, mandarin as male parent hybridization. Metabolomic also show the same result. from the side, the hierarchical clustering analysis results and the neighbor-joining tree can get this conclusion.To sum up, in the citrus metabolite accumulation have stronger organization specificity and have obviously natural variation, also the content and type of metabolites can be used as a home is a strong indicator of evolution and evolution.