Expression of Structural Flavonoid Biosynthesis Genes in Dark-Blue and White Myrtle Berries (Myrtus communis L.)

Abstract

Within the myrtle (Myrtus communis L.) species, different genotypes may produce dark-blue berries or white berries depending on the peel color upon ripening. One dark-blue cultivar and one white myrtle cultivar were used to study the molecular mechanisms underlying flavonoid biosynthesis. The relative expression levels of common (PAL, CHS, CHI, DFR and LDOX) and specific (FLS, ANR, LAR and UFGT) flavonoid genes were analyzed during fruit development by means of quantitative real-time polymerase chain reaction (RT-qPCR). Moreover, the anthocyanin content was determined, and it showed an increase with the ripening of the berries of the dark-blue cultivar. The results showed an increased transcript abundance of PAL, CHI, DFR, LDOX and UFGT gene expression in the dark-blue cultivar compared to the white one, as well as a strong positive correlation between the changes in gene expression and anthocyanin accumulation. The transcript levels of UFGT showed sharp increases at 150 and 180 days after full blooming (DAF) in the dark-blue cultivar, which corresponded with anthocyanin accumulation. However, ripening seemed to modulate the expression of genes implicated in flavonols (i.e., FLS) and flavan-3-ols (i.e., LAR and ANR) in different manners. However, whereas FLS transcript accumulation increased at the end of the ripening period in the dark-blue cultivar, LAR and ANR gene expression decreased in both cultivars.

Determination of Expression Level of Genes Associated with Anthocyanin Biosynthesis in Some Myrtle (Myrtus communis L) Genotypes

“…(Xie et al, 2011). Studies are reporting that the expression level of PAL, CHS, CHIi F3H, ANS and UFGT genes, which are involved in anthocyanin biosynthesis, correlate with anthocyanin accumulation in plant tissues (Boss et al, 1996b(Boss et al, , 1996a(Boss et al, , 1996bGuo and Wang, 2010;Rouholamin et al, 2015;Ben-Simhon et al, 2015;Harel-Beja et al, 2019;Medda et al, 2021;). Studies are reporting that the expression profile of genes associated with anthocyanin biosynthesis changes in different plant species (Xie et al, 2011).…”

“…Flavonoids constitute a subclass of phenolic compounds and contain many different groups. Flavones, flavols, isoflavones and anthocyanins are some members of this group (Janićijević et al, 2007;Medda et al, 2021).…”

“…Nowadays, researches on the anthocyanin biosynthesis pathway and the genes involved in the biosynthesis pathway, determining the expression level of these genes, understanding the gene expression level and the amount of anthocyanin in plant tissues are gaining importance. (Boss et al, 1996b(Boss et al, , 1996aHasegawa et al, 2001;Ban et al, 2003;Guo and Wang, 2010;Xie et al, 2011;Harel-Beja et al, 2019;Medda et al, 2021) The anthocyanin biosynthesis pathway has a structure that does not show much branching. Phenylalanine amonia lyase (PAL), chalconesyntase (CHS), chalconeisomerase (CHI), flavanone3-hydroxylase(F3H), anthocyanidinsynthase (ANS) and UDP are genes involved in the glucoseflavonoid 3-o-glucosyl transferase (UFGT) biosynthesis pathway.…”

Integrated transcriptome and metabolome profiling of Camellia reticulata reveal mechanisms of flower color differentiation

“…Early biosynthetic genes (EBGs) and late biosynthetic genes (LBGs) are the two categories of ABP genes that are found in dicots, along with phenylalanine ammonia-lyase (PAL) genes ( Medda et al, 2021 ). The genes, chalcone synthase (CHS), chalcone isomerase (CHI) , and flavanone 3-hydroxylase (F3H) that are part of the common flavonoid biosynthesis pathway are included in the EBGs.…”