Font Size: a A A

The Biological Function Of PbMYB12 In Regulation Of Flavonoid Biosynthesis In Pear Fruit

Posted on:2019-05-11Degree:MasterType:Thesis
Country:ChinaCandidate:Y X ZhaoFull Text:PDF
GTID:2333330569977766Subject:Pomology
Abstract/Summary:PDF Full Text Request
Pear is one of the important fruit trees in the north of China.As a natural metabolite,flavonoids have important biological functions.Therefore,it is very important to explore the synthesis and metabolism of flavonoids in pear.In the present study,‘Za osu’ pear and its red skin bud mutation ‘Red Zaosu’ pear were used as materials.The t ranscription factor PbMYB12,which was identified by transcriptome from ‘Red Zaosu’ pear.Further screening found that Pb MYB12 could improve the Quercetin 3-O galactos ide,Quercetin 3-O glucoside,Quercetin 3-O arabinoside by improving the transcription al activity of the flavonoid synthesis gene CHS(Chalcone synthase)and elucidate the regulation mechanism of this gene in the flavonoid biosynthesis pathway of pear preli minarily.The main results were as follows:1.The Coding region sequence of PbMYB12 gene was isolated from Chinese white pear and was compared with other flavonoid regulation MYB TFs.The result showed that the gene had 1461 bp of open reading frame(ORF)and encoded a protein containing 486 amino acids.The protein sequence contained a SG7 motif and had a high homology with the AtMYB12 protein sequence.Therefore,the gene was identified as SG7 MYB and named PbMYB12.2.The peels of ‘Zaosu’ pear and its spontaneous sport ‘Red Zaosu’ pear fruit were selected as materials.The results of RT-qPCR and correlation analysis showed that the expression pattern of PbMYB12 gene in two varieties was consistent,and the expression of the gene was significantly positively correlated with the expression of PbCHS,PbCHI,PbFLS,and was significantly positively correlated with Quercetin 3-O galactoside,Quercetin 3-O glucoside,Quercetin 3-O arabinoside components.3.Using the fresh onion subcellular localization analysis indicated that Pb MYB12 gene is targeted to the nucleus.4.The target gene verification was carried out in tobacco by promoter activationassay and luciferase complementary image technology(LCI).The two results indicated that PbMYB12 gene can promote the expression of PbCHS gene.5.PbMYB12 gene was transformed into Arabidopsis thaliana by Agrobacterium tumefaciens-mediated method to obtain transgenic Arabidopsis thaliana strains.Based on this material,we further study the function of PbMYB12.The results showed that the overexpression of PbMYB12 gene promoted the expression of flavonoid synthesis genes,including AtPAL,AtCHS,AtCHI and AtF3 H,in which the expression of AtCHS gene was increased obviously,indicating that PbMYB12 could promote the expression of AtCHS gene and finally regulate the biosynthesis of flavonoids in Arabidopsis.
Keywords/Search Tags:pear, flavonoid, PbMYB12, subcellular localization, target gene
PDF Full Text Request
Related items