Study Of Genes Related To Different Fruit Color Formation In Fragaria Pentaphylla Based On Transcriptome And Metabolome

Fragaria pentaphylla,a unique wild strawberry species in China,with rich fruit colors.The fruits contain three fruit colors,including red,pink and white,and making it a suitable material for studying color genes.Based on this,F.pentaphylla with different fruit colors were as experimental materials,screened the differential metabolites and differential genes related to anthocyanin synthesis by using liquid chromatography mass spectrometry(LC-MS)technology and high-throughput sequencing(RNA seq)technology,and identified the key genes affecting the formation of different fruit colors in F.pentaphylla.Through the development of this study,it will provide a basis for the investigation of different fruit color formation mechanisms and molecular breeding in future.The main results were as follows:(1)Based on LC-MS,a non-targeted metabolomic analysis of fruits with different fruit colors of F.pentaphylla identified 3,249 metabolites,9 differential metabolites related to anthocyanin synthesis and 5 biological pathways.Among them,Abscisic acid,Prunin,Taxifolin,Hesperetin,Pelargonidin3-rutinoside,Daidzein,Malonylgenistin and Genistein were up-regulated in the red fruit and involved in carotenoid,flavonoid,anthocyanin and isoflavone biosynthetic pathways;Apiin and Quercetin were up-regulated in the pink fruit and involved in flavonoid and flavonol biosynthesis;and Myricetin was up-regulated in the white fruit and involved in flavonoid and flavonol biosynthesis.(2)Based on RNA-seq,the transcriptomes of different fruit colors of F.pentaphylla were sequenced,and a total of 28,588 functionally annotated genes were obtained.By two-by-two difference analysis of three libraries of red,pink and white fruit of F.pentaphylla,the numbers of up-regulated and down-regulated genes for red and pink fruit,red and white fruit,and pink and white fruit were 181 and 60;462 and 395;293 and 384.Comparison of the KEGG database revealed a total of 702 differential genes involved in metabolic pathways,of which,82 differential genes were involved in 12 secondary metabolic pathways.(3)A combined metabolomic and transcriptomic analysis was performed to search for differential pathways that may be associated with color change during fruit development and the differential genes involved in the pathways,and 14 nodal genes were selected to have expression characteristics in fruits of three different fruit colors.The structural genes Fp DFR,Fp CHS,Fp CHI,and Fp UFGT were up-regulated in the red fruit,and their expression was significantly higher than that in the pink and white fruit,positively regulating the synthesis of anthocyanin in the red fruit;the structural genes Fp ANR and Fp LAR were up-regulated in the white fruit,promoting the synthesis of Catechin and thus inhibiting the synthesis of anthocyanin in the white fruit;the structural genes Fp PAL were up-regulated in the pink fruit.Transcription factors Fpb HLH18,Fp MYB1,Fp MYB24 and Fp MYB114 synergize structural genes and positively regulate the synthesis of anthocyanins in the red fruit.