Preliminary Study On Anthocyanin Metabolism Mechanism Of Anthurium Andraeanum Mutants

Anthurium andraeanum Lind.is a perennial herb of the genus Araceae and an important indoor flower.Because of its rich flower color,it is very popular among people.Flower color is one of the most important traits that determine the value of Authura,and it is also an important part of breeding work.Due to the complex genetic background of Authura,any new breakthrough in flower color breeding is quite difficult.Therefore,breeding new varieties through mutant traits is expected to speed up the breeding process and have a positive effect on the improvement of Authura flower color.In this study,the main components and differences of pigment in different flower spathes were studied by using 3 Authura cultivar wild type and different flower color types of mutants.The genes related to anthocyanidin synthesis were cloned by molecular biology techniques.The expression characteristics of anthocyanin biosynthesis related genes in mutants of different color systems were investigated by real-time quantitative PCR.The main experimental results were as follows:1.Using 3 Authura cultivar wild type and 19 flower color mutants as materials,the mutant flower color was described by visual inspection and the Royal Horticultural Society Colorimetric Card(RHSCC).Mutants were divided into pink,white and two-color.Qualitative analysis showed that the main pigment of Authura spathes were flavonoids.Qualitative analysis of flavonoids showed that the main components of spathes were flavones and flavonols.The results of UV spectrophotometry showed that there were significant differences in total flavonoids among pink,white and two-color mutants.There was also a significant difference in anthocyanin content of spathes,which was the highest in red spathes,pink spathes were second,white spathes were extremely low or undetected.The presence of anthocyanin was detected in pink part of two-color mutant,while white part was not detected.The main pigment that shows the color of Authura spathes were anthocyanins in the flavonoids.The color depth of mutants were significantly correlated with the anthocyanin content in spathes.2.Using 3 cultivar wild type and 10 flower color mutants as materials,HPLC analysis showed that anthocyanins of cyanidin 3-O-rutinoside(Cy3R)and pelargonidin 3-O-rutinoside(Pg3R)were detected in the wild type,pink-red,pink mutants and the pink part of the two-color mutant,Cy3R was only detected in 'Alabama' pale pink mutant'A1712-1',anthocyanins were not detected in the white mutants.In addition,among different color systems of Authura materials,total anthocyanins in red spathes were the highest,followed by pink mutants and white mutants were not detected.It is indicated that the main anthocyanins of Authura spathes are Cy3R and Pg3R,of which Cy3R is the main body,and the changes of the content of two anthocyanins are positively correlated with the color depth of spathes.3.Molecular biology and bioinformatics techniques were used to clone the cDNA sequence of chalcone isomerase(CH1),leucocysin reductase(LAR)and anthocyanin reductase(ANR)in the anthocyanin synthesis pathway of Authura 'Alabama' spathes.The partial sequence of the coding region of AnCHI is 489 bp,encoding 162 amino acid residues and 1 stop codon(accession number:MK581052);the partial sequence of the coding region of AnLAR gene is 843 bp,encoding 280 amino acid residues and 1 stop codon(accession number:MK581053);the partial sequence of the coding region of AnANR gene is 627 bp,encoding 208 amino acid residues and 1 stop codon(accession number:MK581054).Amino acid sequence deduced by these genes have high similary to the corresponding proteins of other species.4.The expression characteristics of eight anthocyanin synthesis related genes such as AnCHS,AnCHI,AnF3H,AnF3'H,AnDFR,AnANS,AnLAR and AnANR in Authura spathes were analyzed by real-time quantitative PCR.The results showed that although these 8 genes were expressed in mutants,the expression levels were significantly different.The results of comprehensive analysis indicated that the expression levels of AnDFR and AnANS genes significantly affected the flower color traits of Authura spathes.The higher AnDFR and AnANS genes expression,the more red of Authura spathes,and the increased expression of AnLAR and AnANR will cause the color of spathes to fade.