Constitutive expression of bergaptol O-methyltransferase in Glehnia littoralis cell cultures

Abstract

We investigated whether exogenously supplied precursors of bergapten, namely umbelliferone, psoralen and bergaptol, could be utilized to produce bergapten without elicitation in Glehnia littoralis cell suspension cultures. The levels of added psoralen and bergaptol in the medium soon decreased, and this was followed by the detection of bergapten in both culture fluid and cells.Umbelliferone was also incorporated but in this case no bergapten was produced; instead, skimmin, umbelliferone monoglucoside, was detected. To determine whether conversion of psoralen to bergapten was due to enzyme induction by precursor feeding, the transcript accumulations and enzyme activities of bergaptol O-methyltransferase (BMT, EC 2.1.1.69), which catalyzes the last step of bergapten synthesis, and of phenylalanine ammonia-lyase (PAL, EC 4.3.1.5), which catalyzes the initial step of the phenylpropanoid biosynthetic pathway and is known as a marker enzyme of elicitation, were examined. The results showed that both the expression and the activity of BMT

Systematic analysis of O -methyltransferase gene family and identification of potential members involved in the formation of O -methylated flavonoids in Citrus

“…The resulting products might subsequently be converted to the corresponding alcohols that are incorporated into lignin. In addition, a few OMT proteins were found to recognize other substrates, such as pentahydroxyflavone (Gauthier et al, 1998), isoeugenol (Wang et al, 1997;Wang and Pichersky, 1999), bergaptol (Hehmann et al, 2004;Ishikawa et al, 2009), and hydroxyflavone (Kim et al, 2006). In functional subgroup 5, 27 citrus OMTs clustered together with 23 functionally characterized OMTs that have various substrates, such as hydroxyisoflavone (He et al, 1998;He and Dixon, 1996;Zubieta et al, 2001), hydroxyflavonoids and methoxyflavonoids (Cacacea et al, 2003), and isoeugenol (Gang et al, 2002).…”

Selection of Reference Genes for Gene Expression Normalization in Peucedanum praeruptorum Dunn under Abiotic Stresses, Hormone Treatments and Different Tissues

“…However, there are no studies concentrated on the selection of suitable reference genes for P . praeruptorum , in spite of its important medical usage and increasingly studies focusing on the biosynthesis pathway of coumarins [ 9 – 13 ]. Hence, it is useful and urgent for us to identify and select suitable reference genes for future molecular studies using qRT-PCR.…”

Cloning, Functional Characterization, and Catalytic Mechanism of a Bergaptol O-Methyltransferase from Peucedanum praeruptorum Dunn

“…However, some biosynthetic pathways of important compounds, especially the angular pyranocoumarins, are still unclear even in biochemical level ( Bourgaud et al, 2006 ). Although the enzyme activities of some OMT have been biochemically characterized in the past 30 years, only the gene of bergaptol O-methyltransferase (BMT) has been cloned in recent years ( Hehmann et al, 2004 ; Ishikawa et al, 2009 ; Lo et al, 2012 ). This situation largely impedes the investigation of coumarins biosynthesis mechanisms in P. praeruptorum.…”