Onion (Allium Cepa L.) Bulb Flavonoids Contents And Their Iptome Analysis

In this study,we analyzed the anthocyanin and flavonoids compositions,and antioxidant activities in onions with three different colors('W1201'(Red),'W470'(Yellow),'628'(White)).And the relationship between the antioxidant activity was analyzed.In addition,total RNA were isolated from seeding period leaf,root and bulb of onion variety 'W470',compared the four different RNA extraction method to extract onion the effect of different organizational total RNA,explores different groups of total RNA extraction of onion optimal method.We utilized IlluminaHiSeqTM 2000 platform sequencing and bioinformatics for results analysis to find out the differentially expressed genes in three different color onion of bulb organization in.We also discussed the three different color onion flavonoids biosynthesis pathway of differentially expressed genes expression.Moreover,we exploited SSR,SNP marker basing on the transcriptome sequencing data,in order to help the follow-up study conducted by SSR,SNP marker onion germplasm resources evaluation of genetic diversity and molecular marker assisted breeding research.The results are as follows:1.The fresh weight of total anthocyanins were 29.99±1.19,9.64±1.30 and 0.75±0.40 mg·100g-1 fruit in red,yellow and white onions,respectively.Likewise,the fresh weight of total flavonoids were 111.10±5.98,36.64±3.59,and 0 mg·100g-1in red,yellow and white,respectively.Four types of anthocyanins(Delphinidin 3,5-diglycosides,Cyanidin 3,5-diglyco-sides,Cyanidin 3-glycosides and Cyanidin 3-(6'-Malonyl)-glucopyranoside)and two kinds of flavonoids(Quercetin and Quercetin 3-glycosides)were identified in two varieties(red and yellow bulb)of onion by HPLC/DAD-ESI/MS.The total polyphenol contents were also measured by means of Folin-Ciocalteu method.Moreover,all the concentrations of anthocyanins,flavonoids and polyphenols showed significantly positive correlations with antioxidant activities measured by DPPH,ABTS+ and FRAP assays.2.All methods could extracte different quality of RNA in different onion tissue except Tiangene kit can't extract total RNA in onion root.By tested the mass concentration and degree of purity,we found that TaKaRa kit was the best one to extracte RNA for onion leaf in which the RNA mass concentration were 342.31 ?g·g-1 and pBiozol were the optimal RNA extraction methods for onion bulb and root in which the RNA mass concentration were 1119.39 ?g·g-1 and 171.85 ?g·g-1,respectively.Moreover,verified by RT-PCR,leaf RNA by using TaKaRa kit,bulb and root RNA by using pBiozol onion ?-actin gene fragments were successfully expanded.TaKaRa kit was the best one to extracte RNA for onion leaf and pBiozol were the optimal RNA extraction methods for onion bulb and root.3.We obtained 43 325 054 640 nucleotide bases(nt)de novo transcriptome assembly after filtration,totally.In the results of assembly,111 558 Unigene are detected.We got 54138 Unigene which annotate to the NR,KEGG,COG,GO database,respectively.The trend were significant difference by analyze the differentially expressed genes of three varieties showed.There were 12(Red-vs-White),18(White-vs-Yellow)and 10(Yellow-vs-Red)DEGs annotated to the flavonoids biosynthesis pathway of differentially expressed genes,respectively.In addition,we also received 5 767 SSR loci and in total of 329 659 transitions and 145 540 transversions of SNP.