Flower color modification in <i>Rosa hybrida</i> by expressing the <i>S</i>-adenosylmethionine: anthocyanin 3′,5′-<i>O</i>-methyltransferase gene from <i>Torenia hybrida</i>

Abstract

We isolated a cDNA encoding S-adenosylmethionine: anthocyanin 3′,5′-O-methyltransferase (A3′5′OMT) from a cDNA library derived from Torenia hybrida petals that mainly accumulated malvidin type anthocyanins using the petunia A3′OMT cDNA as a probe. The torenia A3′5′OMT shared 52-72% amino acid sequence identity with previously reported AOMTs and belongs to the Group A1 methyltransferase family that also include caffeoyl CoA O-methyltransferase. The recombinant A3′5′OMT produced by Escherichia coli efficiently catalyzed methylation of the 3-glucoside and 3,5-diglucoside of delphinidin and cyanidin, but it did not catalyze the methylation of anthocyanidins, flavonols, or flavones. The torenia A3′5′OMT gene was expressed in Nierembergia sp., the petals of which naturally accumulate anthocyanins derived from delphinidin. The resultant transgenic petals produced methylated anthocyanins, based on malvidin and petunidin, in addition to delphinidin, which indicated that the torenia A3′5′OMT gene was functional in a heterologous plant. Rose petals rarely contain methylated anthocyanins. Transgenic rose petals expressing both a pansy flavonoid 3′,5′-hydroxylase (F3′5′H) and the torenia A3′5′OMT genes accumulated methylated anthocyanins based upon malvidin, petunidin, and peonidin, which comprised up to 88% of the total anthocyanidins, and their magenta color was more brilliant than that of the petals that accumulated delphinidin type anthocyanins by expressing the F3′5′H gene alone. These results indicate that the torenia A3′5′OMT gene is a useful molecular tool for altering and diversifying flower color.

Molecular cloning of flavonoid biosynthetic genes and biochemical characterization of anthocyanin <i>O</i>-methyltransferase of <i>Nemophila menziesii</i> Hook. and Arn.

“…Km and kcat values for delphinidin 3-O-glucoside of NmAMT6 were 26.8±4.67 µM and 13,100±312 s −1 , respectively. The Km value of NmAMT6 is consistent with that of torenia (Nakamura et al 2015), grape (Hugueney et al 2009), tomato (Roldan et al 2014, and peony (Du et al 2015) for anthocyanins ranging from 1.1-123 µM. This study confirms that flavonoid/anthocyaninrelated genes could be comprehensively isolated by transcriptome analysis of petals.…”

“…Interestingly, the ratio of malvidin glucosides produced varied depending on substrates. The low production of malvidin glucosides by NmAMT6 and petunia MT2 AMT is in contrast to that by grape (Hugueney et al 2009), petunia MF1 and MF2 (Provenzano et al 2014), and torenia (Nakamura et al 2015) AMTs, which were demonstrated to efficiently catalyze 3′ and 5′ methylations of delphinidin glucosides to yield malvidin glucosides. Cyclamen AMT was also shown to catalyze malvidin production (Akita et al 2011).…”

Anthocyanins in different Citrus species: an UHPLC‐PDA‐ESI/MSn‐assisted qualitative and quantitative investigation

“…Peonidin‐type anthocyanins are biosynthesized from cyanidin‐based anthocyanins through a methylation reaction catalyzed by the anthocyanin O ‐methyltransferase enzyme. It has been suggested that methylation in plant tissues occurs by producing an alteration in the perceived hue of the pigments, resulting in the reddening/purpling/bluing of flower color . Thus, the presence of considerable amounts of cya 3‐glu and peo 3‐(6 M)‐glu (with their sum accounting for more than 80% of the total anthocyanins in most of the sampled varieties) in pigmented young shoots and flowers in the investigated Citrus genotypes could be explained by the need of Citrus plants to activate biomechanisms targeted at brightening the color of the young tissues to simultaneously assure UV photoprotection and pollinator attraction.…”

Red Pigment Content and Expression of Genes Related to Anthocyanin Biosynthesis in Radishes (Raphanus sativus L.) with Different Colored Flesh

“…Flavanone 3-hydroxylase (F3H) catalyzes flavanone into flavonol and one to two F3H genes were found to be cloned in most plants, and F3H gene has two introns with 350-380 amino acids in protein (Laura, 2013;Kumar et al, 2015). Flavonoid 3′-hydroxylase (F3'H) and flavonoid 3′5′-hydroxylase (F3'5'H), both of which belong to the cytochrome P450 superfamily, catalyze hydroxylation at the 3′ and 3′, 5′ positions of the B-ring of the flavonoids (Forkmann et al, 2014;Nakamura et al, 2015). Dihydroflavonol 4-reductase (DFR), only expressed in the colored organ responsible for anthocyanidin production, catalyzes flavanonols into leucoanthocyanidin (Xu et al, 2014).…”