Research Of Flavonoids And Terpenoids Biosynthesis Genes Based On Transcriptome And Co-expression Network Analysis

Because its characteristics of elegant flower,colorful and enrichment in plant essential oil,rosaceae deciduous shrub Rosa rugosa become economic flower of great research value.Flavonoids is a kind of plant secondary metabolites closely related to flower color,and terpenoid substance is associated with formation of rose essence oil and floral secnt,so it is important to research terpenoids and flavonoids biosynthesis genes and its metabolic regulation network.At present a lack of suitable reference genome of rose and corresponding genetic information,in this study we firstly performed genome-wide gene annotations of the existing rosa genome assembly in our laboratory,identificated structural genes related to flavonoids and terpenoids synthesis,secondly analysised transcriptome data of different organs and periods with the aid of genetic structure information,finally through software WGCNA constructed rose gene co-expression network and screened regulatory gene of flavonoids and terpenoids synthesis.The results were as follows:1.From rose genome we identified 58462 genes encoding proteins and 1943 tRNA,and unified naming;also identified 427 MYB transcription factors,177 bHLH transcription factors,447 WD40 transcription factors,and completed classification of MYB sub-family,comparing with Arabidopsis thaliana and rosaceae five other species(strawberry,apple,pear,plum,peach)we found significant phenomenon of transcription factor family amplification,more 3R-MYB and 4R-MYB in Rosa rugosa.By studying the copy number of structural genes related to flavonoids and terpenoids synthesis in rosaceae,we found that number of flavonoids structure genes was conservative,but there is no F3’5’H gene in rosaceae,the HMGR gene in terpenoids synthesis pathway amplified,also found the HVS and TPS21 gene uniquely in rose.2.Through the transcriptome analysis,we found that relative to the root,stem,leaf,fruit,glucose metabolism and lipid metabolism in rose petals were more active,part of the genes in mevalonate pathway of terpenoid backbone biosynthesis(HMGCR,AtoB,MK,PMK,MPD,HMGS,IDI)and in flavonoids metabolic pathway(CHS,CHI,F3’H,LAR)showed higher expression,expression of genes in lignin synthesis pathway of phenylpropanoid biosynthesis(CAD,CCR,F5H,REF1,HCT,COMT,CSE)decreased,illustrating that material and energy were abundantly supplied in petal when secondary metabolites synthesis,by accelerating mevalonate pathway of terpenoid backbone biosynthesis accumulating more terpenoids in petal,through inhibition of lignin synthesis and promoting the synthesis of flavonoids to accumulate more flower pigment.3.Through WGCNA to construct rose gene co-expression network,2 modules respectively related to flavonoids and terpenoids synthesis were obtained,we screened and got 12 genes in MYB(MYB42,MYB85),bHLH,DBB5,G2-like,HD-ZIP,Trihelix and ZF1 transcription factor family that potential controlled flower color,and 9 genes in MYB(MYB11),GATA1,CO-like,AP2/B3,NAC and bZIP transcription factors that may regulated flower secnt,by STRING interaction network building,we found interactions between IRX12,fah1,CESA4,transcription factors MYB85 with genes related to flower color as well as GUL1,NTRC,APL1,emb2726,BBX15 in CO-like transcription factor family,CGA1 in GATA transcription factor family with genes related to flower scent.