Study On Genes And Substances Related To Anthocyanin Biosynthesis By Low Temperature And High Light Stress In The Leaves Of Begonia Semperflorens

Anthocyanins are the main substances that make plant tissues from red to purple.They are often synthesized and accumulated on plant leaves due to various environmental stresses,so they are called "indicators" of plant stress.There are many factors that affect the anthocyanin synthesis in leaves,such as temperature,photoperiod and hormones.Through the development of transcriptome sequencing technology,we can further explore the mechanism of anthocyanin synthesis induced by low temperature and strong light.In this study,the leaves of Four Seasons Begonia'Super Olympiad' were used as research materials,and the leaves of Four Seasons Begonia were treated under different stress conditions(normal growth condition CK,high light condition HL and low temperature condition LT).From the data measured experimentally,it was found that low temperature and high light stress induced structural genes related to anthocyanin synthesis(PAL,C4 H,4CL,CHI,CHS,F3 H,ANS,ANR,LAR,UFGT,DFR,F3'H)At the same time as expression,transcription genes(MYB,MYC,BHLH,WD40)were also correspondingly stressed.At the same time,it was found that the transfer gene GST also had corresponding expression changes under stress conditions.In addition,it was found that the content of secondary metabolites related to anthocyanins also changed to a certain extent under stress conditions.Therefore,the relevant substances(PA,chalcone,dihydroquercetin)were measured and analyzed by the standard curve method.QRT-PCR analysis of related structural genes and transcribed genes under low temperature and high light stress.(1)The anthocyanin content was significantly increased under low temperature stress.Through the study of related genes on the anthocyanin biosynthetic pathway,the gene expression in the control group was almost unchanged.The key anthocyanin synthesis genes(PAL,C4 H,4CL)And CHS)had relative expression levels after 3h,and significant differences had already appeared at 5h;for mid-and late-phase genes(CHI,F3 H,ANS,ANR,LAR,UFGT,DFR,F3'H),under low temperature stress Ithas been expressed before 1d,and it can be concluded that these several structural factors respond to anthocyanin synthesis under low temperature stress;12 regulatory genes(MYB,MYC,BHLH,WD40)also show changes in the corresponding gene expression under continuous low temperature stress Therefore,the accumulation of anthocyanins in the green leaf variety of Four Seasons Begonia under low temperature conditions requires two types of genes: structure and regulatory genes to affect anthocyanin metabolism.(2)The content of anthocyanins increased significantly under high light stress.Similarly,by studying related genes on the anthocyanin biosynthetic pathway,the gene expression in the control group was almost unchanged.The key anthocyanin synthesis genes(PAL,C4 H,4CL,CHS)all reached the peak of gene expression at 9h,and the relative genes at the middle and late stages(CHI,F3 H,ANS,ANR,LAR,UFGT,DFR,F3'H)also reached relative levels at 9h.Peak expression level;12regulatory genes(MYB,MYC,BHLH,WD40)under relatively high light stress showed relatively higher changes.It can be deduced that the accumulation of anthocyanins under high light stress is also inextricably linked to the structure and regulatory genes;it is also preliminarily deduced that the low-temperature anthocyanin synthesis pathway in leaves of Begonia sinensis compared with that of anthocyanins under high light The synthetic pathway is more complicated.(3)Under low temperature stress and high light stress treatments,the relative expression of GST gene changes,and the relative expression level begins at 3 hours.It can be inferred that the anthocyanin synthesis of begonia leaves under low temperature and high light,and the transport gene GST also There is a connection.(4)Both low temperature(15/5?)and high light(600 ?molm-2s-1)can significantly promote the accumulation of anthocyanins in leaves of Begonia sibirica,and have obvious changing characteristics.After treatment of leaves,four physiological indicators of proanthocyanidins,chalcone,dihydroquercetin and anthocyanins were measured to analyze the changes in substance content and anthocyanin synthesis under stress.The results showed that there was almost no change in these four contents in the normal temperature control group,while in the experimental group(low temperature induced and high light induced),the contents of the three substances,proanthocyanidins,chalcones and dihydroquercetin,preceded theaccumulation of anthocyanins.As the metabolites of the metabolic pathway,the content of these three substances is closely related to the accumulation of anthocyanins.