Study On Flavonoids And Biosynthesis Related Gene Expression Of Coreopsis Tinctoria Nutt.

Coreopsis tinctoria Nutt.it is an annual herb of the genus Compositae of Asteraceae.The main active components of C.tinctoria are flavonoids.So far,more than 50 flavonoids extracted and identified from its flowers and seeds involve many categories and a variety of biological activities,which have important medicinal and economic value.Xinjiang is the main producing area of C.tinctoria,and the common cultivated C.tinctoria has two color types(reddish brown at the base of the tongue flower / yellow at the top = 2/3-3/4,marked with LS;ligulate flower all yellow,marked with JS).In view of the common problems such as uneven quality of these two color types of C.tinctoria(LS and JS),in this study,the differences of growth and quality of LS and JS at different growth stages were analyzed by pot substrate cultivation,and the expressions of flavonoids and their biosynthesis related genes at flowering stages were studied by metabonomics and transcriptome techniques.The main results are as follows:(1)The change trends of growth and biomass indexes of LS and JS in the whole growing period(seedling stage,flower bud differentiation stage,flower bud stage,early flowering stage,full flowering stage,late flowering stage)were the same,and the plant height and biomass of JS were slightly higher than those of LS.The total flavonoids contents in different stages of LS and JS were significantly different,and there was a significant positive correlation between the total flavonoids content in flower and plant height,fresh weight of flower,fresh weight of stem and other growth indexes at flowering stages.The total flavonoids contents in inflorescences of LS and JS at early flowering stage and full flowering stage were significantly higher than those in roots,stems and leaves at all stages of growing period.The total flavonoids content in LS at bud stage and full flowering stage was significantly higher than that at JS.The results showed that the quality of LS at bud stage and full flowering stage was better than that at JS,so it was a suitable time for harvest.(2)There were significant differences in anthocyanin content between LS and JS at flowering stages.The anthocyanin content of LS at bud stage and full flowering stage was significantly higher than that at JS,and the change trend of total flavonoids content was consistent.The activities of PAL,C4 H,CHS,CHI,F3 H,F3'H and DFR had obvious spatio-temporal specificity at four stages of LS and JS.CHS,CHI,C4 H and F3'H were significantly correlated with the total flavonoids content and anthocyanins content at the flowering stages of LS or JS,which were the key enzymes in the flavonoids biosynthesis.(3)A total of 165 flavonoids(46 flavonoids,42 flavonols,22 anthocyanins,18 chalcone,12 dihydroflavonols,9 isoflavones,8 dihydroflavonoids,6 flavanols and 2 tannins)were determined in buds and inflorescences of LS and JS.Flavonoids,flavonols and anthocyanins were the main flavonoids in LS and JS.There were significant differences in the accumulation patterns of flavonoids at different stages of LS and JS.The accumulation of flavonoids in LS begined at the flower bud stage,and cyanidin-3,5-O-diglucoside(cyanin)was the key flavonoid metabolite at flowering stage.The accumulation of JS flavonoids also begined at the flower bud stage,but more flavonols were accumulated at the flowering stage,such as isohyperoside,myricetin-3-O-(6''-malony)glucoside,gossypetin-3-O-(6''-malonyl)glucoside,and other major flavonoid metabolites.A total of 17 kinds of DAFs changed significantly during the four stages of LS and JS,and more were accumulated in LS,including 10 anthocyanins,1 flavonoids,2 flavonols,2 dihydroflavonols,1 dihydroflavonoids and 1 chalcone.The accumulated content of pyrethrin and pelargonium pigment may be the main reason for the difference of flower color between LS and JS.(4)Through transcriptome sequencing(RNA-seq)analysis of 24 samples from four stages of LS and JS,121 differential genes(DEGs)related to flavonoid biosynthesis were identified at four stages of LS and JS,of which 61 DEGs were highly expressed at different stages,and 24 DEGs with significant relationship with key metabolites were identified.Candidate genes Cluster-28756.299649(F3H)and Cluster-28756.230942(3GT)were core gene members of flavonoid biosynthesis in LS and JS.The expression of MYB is the most in LS and JS.There was a significant relationship between MYB90,MYB111 and several structural genes,and the transcription factor(TF)Cluster-28756.143139(MYB90a)might be related to the regulation of color.