基于转录组和代谢组的尖萼耧斗菜花色变异机制研究

Aquilegia is an important domestic plant resource in the northeast of China,among them,A.oxysepala is good landscape material with great potential for its dark red sepals,elegant shape,intensive coverage and well adaption.A.oxysepala f.pallidiflora is the result of evolutionary adaptation to the environment with white sepals.Floral color directly affects quantity and quality of plant pollination,fruiting and offspring populations,and variation reflects plant adaptation to environments.Therefore,both A.oxysepala and A.oxysepala f.pallidiflora are appropriate for floral color evolution and anthocyanin biosynthesis researches.[Objective]This research aimed to reveal the material basis and molecular mechanisms of floral color variation between A.oxysepala and A.oxysepala f.pallidiflora,which provided a basis for the breeding and conservation of Aquilegia.[Methods]A.oxysepala and A.oxysepala f.pallidiflora were used as materials.Sepals color evaluation was conducted by comparing with Royal Horticultural Society Color Chart(RHSCC).Total anthocyanin,flavonoids,chlorophyll and carotenoids contents were measured by ethanol-HCl,aluminum nitrate colorimetric and acetone methods.Transcriptome was constructed using the second-generation Illumina sequencing platform;broad-target metabolites were detected by ultra performance liquid chromatography tandem mass spectrometry(UPLC-MS/MS);transcription factors that regulated anthocyanin were identified by co-analysis and WGCNA.[Results]Anthocyanin and total flavonoids were the main pigments in two Aquilegia species.Total of 14120 differential expressed genes and 1159 metabolites were identified.Genes and metabolites were both enriched on Phenylpropanoid biosynthesis(ath00940)and Flavonoid biosynthesis(ath00941)pathways.15 functional genes and 17 metabolites were annotated according to KEGG.The main pigments of A.oxysepala were Cyanidin-3-O-(6''-O-malonyl)glucoside,Delphinidin-3-O-(3'',6''-O-dimalonyl)glucoside and Cyanidin-3-O-(3'',6''-O-dimalonyl)glucoside,while Apigenin-8-C-Glucoside,Apigenin-6-C-glucoside and Kaempferol-3-O-galactoside for A.oxysepala f.pallidiflora.Compared with A.oxysepala,anthocyanin biosynthesis functional genes down-regulated in A.oxysepala f.pallidiflora with competition from F3'5'H and FLS,the substrate flowed to flavonoids and flavonol biosynthesis pathways,which was the reason for the sepals color variation.According to co-joint and WGCNA,3 transcription factors that regulated anthocyanin biosynthesis functional genes:WRKY(gene-AQUCO_02700161v1),C2H2(gene-AQUCO_01000437v1)and bHLH(gene-AQUCO_05400130v1)were identified.They significantly up-regulated during floral development in A.oxysepala,however,no changes occurred in A.oxysepala f.pallidiflora,which could play an important role in floral color variation in A.oxysepala.[Conclusion]This research illustrated the molecular mechanism of floral color variation between A.oxysepala and A.oxysepala f.pallidiflora,which provided a new insight for evolution of ecological adaptations study in the floral color,while laid the foundation for the in-depth study and utilization of A.oxysepala.