Inactivation of pea genes by RNAi supports the involvement of two similar O-methyltransferases in the biosynthesis of (+)-pisatin and of chiral intermediates with a configuration opposite that found in (+)-pisatin

Kaimoyo, Evans; VanEtten, Hans D.

doi:10.1016/j.phytochem.2007.06.013

Cited by 29 publications

(34 citation statements)

References 51 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, an IFR that produces (3 S )-isoflavanone has not yet been reported. In the isoflavonoid pathway of pea, (+)-pisatin is reportedly biosynthesized from (3 R )-isoflavanone (sophorol) and subsequently from (3 R ,4 R )-isoflavanol (7,2′-dihydroxy-4′,5′-methylenedioxyisoflavanol) via an achiral intermediate of isoflav-3-ene (7,2′-dihydroxy-4′,5′-methylenedioxyisoflav-3-ene) (Paiva et al 1994, DiCenzo and VanEtten 2006, Kaimoyo and VanEtten 2008, Celoy and VanEtten 2014). According to this hypothesis, the last steps of (+)-pterocarpan formation should involve unidentified enzymes (Celoy and VanEtten 2014).…”

Section: Discussionmentioning

confidence: 99%

“…2′-Hydroxyisoflavanols (DMI and THI) were prepared from 2′-hydroxyisoflavanones (3 R )-vestitone, (3 RS )-vestitone and (3 R )-7,2′,4′-trihydroxyisoflavanone by chemical reduction with NaBH 4 (Kaimoyo and VanEtten 2008), and diastereomeric products were separated by TLC. (–)-3,9-Dihydroxypterocarpan was also made by chemical reduction with NaBH 4 from (3 R )-7,2′,4′-trihydroxyisoflavanone (Dewick 1976).…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

The Missing Link in Leguminous Pterocarpan Biosynthesis is a Dirigent Domain-Containing Protein with Isoflavanol Dehydratase Activity

Uchida

Akashi

Aoki

2017

Plant and Cell Physiology

View full text Add to dashboard Cite

Pterocarpan forms the basic structure of leguminous phytoalexins, and most of the isoflavonoid pathway genes encoding the enzymes responsible for its biosynthesis have been identified. However, the last step of pterocarpan biosynthesis is a ring closure reaction, and the enzyme that catalyzes this step, 2′-hydroxyisoflavanol 4,2′-dehydratase or pterocarpan synthase (PTS), remains as an unidentified ‘missing link’. This last ring formation is assumed to be the key step in determining the stereochemistry of pterocarpans, which plays a role in their antimicrobial activity. In this study, a cDNA clone encoding PTS from Glycyrrhiza echinata (GePTS1) was identified through functional expression fractionation screening of a cDNA library, which requires no sequence information, and orthologs from soybean (GmPTS1) and Lotus japonicus (LjPTS1) were also identified. These proteins were heterologously expressed in Escherichia coli and biochemically characterized. Surprisingly, the proteins were found to include amino acid motifs characteristic of dirigent proteins, some of which control stereospecific phenoxy radical coupling in lignan biosynthesis. The stereospecificity of substrates and products was examined using four substrate stereoisomers with hydroxy and methoxy derivatives at C-4′. The results showed that the 4R configuration was essential for the PTS reaction, and (−)- and (+)-pterocarpans were produced depending on the stereochemistry at C-3. In suspension-cultured soybean cells, levels of the GmPTS1 transcript increased temporarily prior to the peak in phytoalexin accumulation, strongly supporting the possible involvement of PTS in pterocarpan biosynthesis.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

The Missing Link in Leguminous Pterocarpan Biosynthesis is a Dirigent Domain-Containing Protein with Isoflavanol Dehydratase Activity

Uchida

Akashi

Aoki

2017

Plant and Cell Physiology

View full text Add to dashboard Cite

show abstract

“…At the time this paper was published, it appeared to be the first case of producing transgenic plant tissues with reduced capability to accumulate a given phytoalexin and demonstrating that such a tissue was less resistant to fungal infection [85]. Additionally, this loss-of-function genetic approach afforded direct evidence of the role of pterocarpan phytoalexins in plant defense mechanisms [77]. …”

Section: Genetic Manipulation Of Phytoalexin Production and Diseasmentioning

confidence: 99%

“…IFS: 2-hydroxy isoflavanone synthase; DMI: 7,2′-dihydroxy-4′-methoxy-isoflavanol; DMDI: 7,2′-dihydroxy-4′,5′-methylenedioxy-isoflavanol; HMM: 6α-hydroxymaackiain 3- O -methyltransferase; HI4′OMT: SAM: 2,7,4′-trihydroxy-isoflavanone 4′- O -methyltransferase (adapted from [76,77]). The dashed arrows represent hypothetic steps and the solid arrows denote reactions for which the catalyzing enzymes have been cloned.…”

Section: Figurementioning

confidence: 99%

Modulation of Phytoalexin Biosynthesis in Engineered Plants for Disease Resistance

Jeandet

Clément

Courot

et al. 2013

IJMS

142

119

View full text Add to dashboard Cite

Phytoalexins are antimicrobial substances of low molecular weight produced by plants in response to infection or stress, which form part of their active defense mechanisms. Starting in the 1950’s, research on phytoalexins has begun with biochemistry and bio-organic chemistry, resulting in the determination of their structure, their biological activity as well as mechanisms of their synthesis and their catabolism by microorganisms. Elucidation of the biosynthesis of numerous phytoalexins has permitted the use of molecular biology tools for the exploration of the genes encoding enzymes of their synthesis pathways and their regulators. Genetic manipulation of phytoalexins has been investigated to increase the disease resistance of plants. The first example of a disease resistance resulting from foreign phytoalexin expression in a novel plant has concerned a phytoalexin from grapevine which was transferred to tobacco. Transformations were then operated to investigate the potential of other phytoalexin biosynthetic genes to confer resistance to pathogens. Unexpectedly, engineering phytoalexins for disease resistance in plants seem to have been limited to exploiting only a few phytoalexin biosynthetic genes, especially those encoding stilbenes and some isoflavonoids. Research has rather focused on indirect approaches which allow modulation of the accumulation of phytoalexin employing transcriptional regulators or components of upstream regulatory pathways. Genetic approaches using gain- or less-of functions in phytoalexin engineering together with modulation of phytoalexin accumulation through molecular engineering of plant hormones and defense-related marker and elicitor genes have been reviewed.

show abstract

“…In some of their earlier studies on the elicitation of phytoalexins (antimicrobial compounds produced in response to microbial infection), Cruickshank and Perrin (7, 8) demonstrated that the isoflavonoid derivative (+)‐pisatin (Figure 1) was produced in opened pea pods exposed to a spore suspension of Monilinia fructicola or to solutions of metal ions such as silver or copper. In our previous studies (9, 10) on the biosynthesis of (+)‐pisatin, we routinely used aqueous CuCl 2 to elicit the synthesis of this compound. Preliminary studies by Cuello and Yue, University of Arizona, showed that the application of a constant electric current to hairy roots of Hyoscyamus muticus stimulated the production of the alkaloid hyoscyamine (unpublished results).…”

Section: Introductionmentioning

confidence: 99%

Sub‐lethal Levels of Electric Current Elicit the Biosynthesis of Plant Secondary Metabolites

Kaimoyo

Farag

Sumner

et al. 2008

Biotechnology Progress

View full text Add to dashboard Cite

Many secondary metabolites that are normally undetectable or in low amounts in healthy plant tissue are synthesized in high amounts in response to microbial infection. Various abiotic and biotic agents have been shown to mimic microorganisms and act as elicitors of the synthesis of these plant compounds. In the present study, sub-lethal levels of electric current are shown to elicit the biosynthesis of secondary metabolites in transgenic and non-transgenic plant tissue. The production of the phytoalexin (+)-pisatin by pea was used as the main model system. Nontransgenic pea hairy roots treated with 30-100 mA of electric current produced 13 times higher amounts of (+)-pisatin than did the non-elicited controls. Electrically elicited transgenic pea hairy root cultures blocked at various enzymatic steps in the (+)-pisatin biosynthetic pathway also accumulated intermediates preceding the blocked enzymatic step. Secondary metabolites not usually produced by pea accumulated in some of the transgenic root cultures after electric elicitation due to the diversion of the intermediates into new pathways. The amount of pisatin in the medium bathing the roots of electro-elicited roots of hydroponically cultivated pea plants was 10 times higher 24 h after elicitation than in the medium surrounding the roots of nonelicited control plants, showing not only that the electric current elicited (+)-pisatin biosynthesis but also that the (+)-pisatin was released from the roots. Seedlings, intact roots or cell suspension cultures of fenugreek (Trigonella foenum-graecum), barrel medic, (Medicago truncatula), Arabidopsis thaliana, red clover (Trifolium pratense) and chickpea (Cicer arietinum) also produced increased levels of secondary metabolites in response to electro-elicitation. On the basis of our results, electric current would appear to be a general elicitor of plant secondary metabolites and to have potential for application in both basic and commercial research.

show abstract

Inactivation of pea genes by RNAi supports the involvement of two similar O-methyltransferases in the biosynthesis of (+)-pisatin and of chiral intermediates with a configuration opposite that found in (+)-pisatin

Cited by 29 publications

References 51 publications

The Missing Link in Leguminous Pterocarpan Biosynthesis is a Dirigent Domain-Containing Protein with Isoflavanol Dehydratase Activity

The Missing Link in Leguminous Pterocarpan Biosynthesis is a Dirigent Domain-Containing Protein with Isoflavanol Dehydratase Activity

Modulation of Phytoalexin Biosynthesis in Engineered Plants for Disease Resistance

Sub‐lethal Levels of Electric Current Elicit the Biosynthesis of Plant Secondary Metabolites

Contact Info

Product

Resources

About