| Moringa oleifera Lam.is a perennial evergreen tree belonging to Moringa genus in the Moringa family,mainly distributed in tropical and subtropical areas.In recent years,the research has become a hot topic on the chemical constituents and biological activities in the leaves of Moringa oleifera.Studies have shown that the samples of Moringa oleifera leaves from different producing areas have differences in the contents of nutrients,total flavonoids and total polyphenols.Whether there are differences in secondary metabolites,especially phenolic compounds among Moringa oleifera leaves from different producing areas,and whether such differences are caused by genetic factors or habitat factors,there is few report on this research.In view of this,this study focused on the quality of Moringa oleifera leaves.The genetic and habitat factors of samples from different producing areas were studied to explore the factors that influence the chemical diversity of Moringa oleifera leaves and analyze the causes of their quality.This paper provided theoretical support and technical guidance for the quality control and breed selection of Moringa oleifera leaves,and laid a research foundation for the benign development of Moringa oleifera leaves with the homology of medicine and food.The main research contents were as follows:(1)The total polyphenols,11 phenolic components and antitumor activity of Moringa oleifera from different parts and Moringa oleifera leaves with different processing methods were analyzed.The results showed that the contents of total polyphenols,phenolic components and antitumor activities(Hela and MDA-MB-231)of the dried leaves at 60?were higher on the whole.Therefore,the dried Moringa oleifera leaves at 60?were selected as the object of further research.It provided theoretical guidance for the follow-up study on the quality control of Moringa oleifera leaves from different producing areas.(2)Total polyphenols and antitumor activities(Hela and MDA-MB-231)of 35different Moringa oleifera leaves were investigated by UV and MTS methods.By using UPLC-MS/MS technique,the chemical diversity evaluation system of Moringa oleifera leaves from different producing areas was established with quantitative analysis of 11 phenolic components.The content of phenolic substances and anticancer activity of Moringa oleifera leaves from different producing areas were significantly different,indicating that the chemical diversity of Moringa oleifera leaves under different habitat conditions was rich.(3)The chemical diversity of Moringa oleifera leaves was analyzed based on untargeted metabolomics.A total of 2084(ESI~+mode)and 1294(ESI~-mode)compounds were identified by primary(MS1)and secondary(MS2)spectra of metabolites.Principal component analysis showed that three groups of samples were located in different quadrants of PCA,indicating that the changes of external habitat promoted the regionality of metabolites.Cluster analysis showed that the quality of Moringa oleifera leaves was unstable due to the differences in habitat conditions,which manifested that the samples from three producing areas clustered together separately,illustrating that the species and abundance of metabolites appeared diversity with the change of habitat conditions.According to OPLS-DA and KEGG analysis,the number of differential metabolites between producing areas was different and the metabolic pathways involved were also different.The VIP values of chlorogenic acid,quercetin and quercetin-3?-D-glucoside were all greater than 5,ranking in the top 10 among all the VIP values of differential metabolites,contributing greatly to sample differentiation.Flavonoid biosynthesis and phenylpropanoid biosynthesis were the important metabolic pathways in the biosynthesis of other secondary metabolites.Phenolic compounds such as chlorogenic acid,kaempferol,quercetin and ferulic acid were involved,indicating the important role of phenolic components in biosynthesis.(4)Using transcriptome sequencing technology to explore the relationship between genetic factors and chemical diversity of Moringa oleifera leaves,transcriptome sequencing was conducted on Moringa oleifera leaves from Dehong,Baoshan and Yuanmou regions.After the sequencing data of the samples from 3producing areas were assembled by the software,the total assembled bases of the Unigene were 61149357,the number of N50 was 6433,and the length of N50 was3069bp.By annotated statistics of Moringa oleifera leaves,the number of Unigene in NR,KEGG,KOG,and Swiss Prot databases was 27491,25646,17235,and 21545,respectively.The number of Unigene in the four databases was 28724,and the number of Unigene in the non-database was 14319.There were 8 trends in the trend analysis of the different genes in Moringa oleifera leaves from three producing areas,and the corresponding gene numbers were 948,995,799,1309,492,599,712 and 679,respectively.According to KEGG's annotations,24 enzymes related to the candidate differential genes in Moringa oleifera leaves from three producing areas were involved in the flavonoid biosynthetic pathway,48 enzymes related to the candidate differential genes in Moringa oleifera leaves from three producing areas were involved in the phenylpropanoid biosynthetic pathway.According to the correlation analysis of metabolome and transcriptome,genes and metabolites were positively or negatively correlated,which were closely related to the content and quantity of compounds,promoting the diversity of the chemical components in Moringa oleifera leaves.The VIP values of 36 genetic factors from Moringa oleifera leaves were all higher than 1.0,which were the main factors related to the 11 phenolic components.(5)The effects of 9 habitat factors on 11 phenolic components in Moringa oleifera leaves were analyzed by SPSS statistical method,and the relationships among geographical factors,climate factors,soil factors and 11 phenolic components in Moringa oleifera leaves were clarified.The results showed that 11 phenolic components of Moringa oleifera leaves were correlated with habitat factors.The relationship of the genetic and habitat factors with the chemical diversity of Moringa oleifera leaves was investigated by the orthogonal partial least squares method(OPLS).The VIP values of the top four habitat factors(annual average temperature,annual sunshine hours,available phosphorus and organic matter)were all greater than1.35,which was the most important factor in the chemical diversity of Moringa oleifera leaves.Through Pearson correlation analysis,habitat factors(annual average temperature,annual sunshine hours,available phosphorus)were positively correlated with 6 phenolic components(gallic acid,chlorogenic acid,ferulic acid,isoquercetin,quercitrin,quercetin),while organic matter was negatively correlated with 6 phenolic components.For the same species,the genetic factors(Unigene0032837,Unigene0027007,Unigene0009862,Unigene0000531,Unigene0040004,Unigene0040782,Unigene0041804)in flavonoid and phenylpropanoid biosynthesis were positively correlated with 6 phenolic components and strongly positively correlated with habitat factors(annual average temperature,annual sunshine hours,available phosphorus)(r:0.8-1.0),and they were strongly negatively correlated with organic matter(r absolute value:0.8-1.0).Therefore,Moringa oleifera was planted in areas with high annual average temperature,high annual sunshine hours,high available phosphorus and low organic matter to increase the content of gallic acid,chlorogenic acid,ferulic acid,isoquercetin,quercitrin and quercetin. |
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