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The isolation and mapping of a novel hydroxycinnamoyltransferase in the globe artichoke chlorogenic acid pathway.

Comino C, Hehn A, Moglia A, Menin B, Bourgaud F, Lanteri S, Portis E - BMC Plant Biol. (2009)

Bottom Line: The leaves of globe artichoke and cultivated cardoon (Cynara cardunculus L.) have significant pharmaceutical properties, which mainly result from their high content of polyphenolic compounds such as monocaffeoylquinic and dicaffeoylquinic acid (DCQ), and a range of flavonoid compounds.A novel acyltransferase involved in the biosynthesis of CGA in globe artichoke has been isolated, characterized and mapped.This is a good basis for our effort to understand the genetic basis of phenylpropanoid (PP) biosynthesis in C. cardunculus.

View Article: PubMed Central - HTML - PubMed

Affiliation: DiVaPRA Plant Genetics and Breeding, University of Torino, Grugliasco (Torino), Italy. cinzia.comino@unito.it

ABSTRACT

Background: The leaves of globe artichoke and cultivated cardoon (Cynara cardunculus L.) have significant pharmaceutical properties, which mainly result from their high content of polyphenolic compounds such as monocaffeoylquinic and dicaffeoylquinic acid (DCQ), and a range of flavonoid compounds.

Results: Hydroxycinnamoyl-CoA:quinate hydroxycinnamoyltransferase (HQT) encoding genes have been isolated from both globe artichoke and cultivated cardoon (GenBank accessions DQ915589 and DQ915590, respectively) using CODEHOP and PCR-RACE. A phylogenetic analysis revealed that their sequences belong to one of the major acyltransferase groups (anthranilate N-hydroxycinnamoyl/benzoyltransferase). The heterologous expression of globe artichoke HQT in E. coli showed that this enzyme can catalyze the esterification of quinic acid with caffeoyl-CoA or p-coumaroyl-CoA to generate, respectively, chlorogenic acid (CGA) and p-coumaroyl quinate. Real time PCR experiments demonstrated an increase in the expression level of HQT in UV-C treated leaves, and established a correlation between the synthesis of phenolic acids and protection against damage due to abiotic stress. The HQT gene, together with a gene encoding hydroxycinnamoyl-CoA:shikimate/quinate hydroxycinnamoyltransferase (HCT) previously isolated from globe artichoke, have been incorporated within the developing globe artichoke linkage maps.

Conclusion: A novel acyltransferase involved in the biosynthesis of CGA in globe artichoke has been isolated, characterized and mapped. This is a good basis for our effort to understand the genetic basis of phenylpropanoid (PP) biosynthesis in C. cardunculus.

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A simplified diagram of enzymes and major products in the synthesis of chlorogenic acid in plants. The product names appear between the arrows. Enzymes involved in this pathway are: PAL, phenylalanine ammonia lyase; C4H, cinnamate 4-hydroxylase; 4CL, 4-hydroxycinnamoyl-CoA ligase; HCT, hydroxycinnamoyl-CoA shikimate/quinate hydroxycinnamoyl transferase; HQT, hydroxycinnamoyl CoA quinate hydroxycinnamoyl transferase; C3'H, p-coumaroyl ester 3'-hydroxylase.
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Figure 1: A simplified diagram of enzymes and major products in the synthesis of chlorogenic acid in plants. The product names appear between the arrows. Enzymes involved in this pathway are: PAL, phenylalanine ammonia lyase; C4H, cinnamate 4-hydroxylase; 4CL, 4-hydroxycinnamoyl-CoA ligase; HCT, hydroxycinnamoyl-CoA shikimate/quinate hydroxycinnamoyl transferase; HQT, hydroxycinnamoyl CoA quinate hydroxycinnamoyl transferase; C3'H, p-coumaroyl ester 3'-hydroxylase.

Mentions: The CGA biosynthesis pathway has been the target of some detailed research, mainly focused among Solanaceae species [24-26] (Fig. 1). Even though little direct information is as yet available concerning the biosynthesis of di- and tri-caffeoylquinic acid, the prior accumulation of CGA does appear to be necessary. Three distinct pathways have been proposed for the synthesis of CGA: (1) the trans-esterification of caffeoyl-CoA and quinic acid via hydroxycinnamoyl-CoA:quinate hydroxycinnamoyl transferase (HQT) activity [27,28]; (2) the hydroxylation of p-coumaroyl quinate to CGA [25]; and (3) the hydroxylation of p-coumaroyl shikimate to caffeoyl shikimic acid, which is then converted to caffeoyl-CoA, a substrate of hydroxycinnamoyl-CoA:shikimate hydroxycinnamoyl transferase HCT [24]. The silencing of the HQT gene in tobacco and tomato results in a 98% reduction in CGA level, but does not affect lignin formation, so in these species at least, the first two of these routes are probably responsible for the biosynthesis and accumulation of CGA [25]. On the other hand, a lowered HCT expression in tobacco [29], Pinus radiata [30] and Medicago sativa [31] changes lignin amount and composition, thereby implicating the third pathway in lignin biosynthesis. A fourth route, which uses caffeoyl-glucoside as the active intermediate, has been described in sweet potato [26]. Although the globe artichoke HCT sequence is similar to that of tobacco HCT, its activity is more closely related to that of tobacco and tomato HQT, in showing a preference for quinic over shikimic acid as acceptor [32].


The isolation and mapping of a novel hydroxycinnamoyltransferase in the globe artichoke chlorogenic acid pathway.

Comino C, Hehn A, Moglia A, Menin B, Bourgaud F, Lanteri S, Portis E - BMC Plant Biol. (2009)

A simplified diagram of enzymes and major products in the synthesis of chlorogenic acid in plants. The product names appear between the arrows. Enzymes involved in this pathway are: PAL, phenylalanine ammonia lyase; C4H, cinnamate 4-hydroxylase; 4CL, 4-hydroxycinnamoyl-CoA ligase; HCT, hydroxycinnamoyl-CoA shikimate/quinate hydroxycinnamoyl transferase; HQT, hydroxycinnamoyl CoA quinate hydroxycinnamoyl transferase; C3'H, p-coumaroyl ester 3'-hydroxylase.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2664813&req=5

Figure 1: A simplified diagram of enzymes and major products in the synthesis of chlorogenic acid in plants. The product names appear between the arrows. Enzymes involved in this pathway are: PAL, phenylalanine ammonia lyase; C4H, cinnamate 4-hydroxylase; 4CL, 4-hydroxycinnamoyl-CoA ligase; HCT, hydroxycinnamoyl-CoA shikimate/quinate hydroxycinnamoyl transferase; HQT, hydroxycinnamoyl CoA quinate hydroxycinnamoyl transferase; C3'H, p-coumaroyl ester 3'-hydroxylase.
Mentions: The CGA biosynthesis pathway has been the target of some detailed research, mainly focused among Solanaceae species [24-26] (Fig. 1). Even though little direct information is as yet available concerning the biosynthesis of di- and tri-caffeoylquinic acid, the prior accumulation of CGA does appear to be necessary. Three distinct pathways have been proposed for the synthesis of CGA: (1) the trans-esterification of caffeoyl-CoA and quinic acid via hydroxycinnamoyl-CoA:quinate hydroxycinnamoyl transferase (HQT) activity [27,28]; (2) the hydroxylation of p-coumaroyl quinate to CGA [25]; and (3) the hydroxylation of p-coumaroyl shikimate to caffeoyl shikimic acid, which is then converted to caffeoyl-CoA, a substrate of hydroxycinnamoyl-CoA:shikimate hydroxycinnamoyl transferase HCT [24]. The silencing of the HQT gene in tobacco and tomato results in a 98% reduction in CGA level, but does not affect lignin formation, so in these species at least, the first two of these routes are probably responsible for the biosynthesis and accumulation of CGA [25]. On the other hand, a lowered HCT expression in tobacco [29], Pinus radiata [30] and Medicago sativa [31] changes lignin amount and composition, thereby implicating the third pathway in lignin biosynthesis. A fourth route, which uses caffeoyl-glucoside as the active intermediate, has been described in sweet potato [26]. Although the globe artichoke HCT sequence is similar to that of tobacco HCT, its activity is more closely related to that of tobacco and tomato HQT, in showing a preference for quinic over shikimic acid as acceptor [32].

Bottom Line: The leaves of globe artichoke and cultivated cardoon (Cynara cardunculus L.) have significant pharmaceutical properties, which mainly result from their high content of polyphenolic compounds such as monocaffeoylquinic and dicaffeoylquinic acid (DCQ), and a range of flavonoid compounds.A novel acyltransferase involved in the biosynthesis of CGA in globe artichoke has been isolated, characterized and mapped.This is a good basis for our effort to understand the genetic basis of phenylpropanoid (PP) biosynthesis in C. cardunculus.

View Article: PubMed Central - HTML - PubMed

Affiliation: DiVaPRA Plant Genetics and Breeding, University of Torino, Grugliasco (Torino), Italy. cinzia.comino@unito.it

ABSTRACT

Background: The leaves of globe artichoke and cultivated cardoon (Cynara cardunculus L.) have significant pharmaceutical properties, which mainly result from their high content of polyphenolic compounds such as monocaffeoylquinic and dicaffeoylquinic acid (DCQ), and a range of flavonoid compounds.

Results: Hydroxycinnamoyl-CoA:quinate hydroxycinnamoyltransferase (HQT) encoding genes have been isolated from both globe artichoke and cultivated cardoon (GenBank accessions DQ915589 and DQ915590, respectively) using CODEHOP and PCR-RACE. A phylogenetic analysis revealed that their sequences belong to one of the major acyltransferase groups (anthranilate N-hydroxycinnamoyl/benzoyltransferase). The heterologous expression of globe artichoke HQT in E. coli showed that this enzyme can catalyze the esterification of quinic acid with caffeoyl-CoA or p-coumaroyl-CoA to generate, respectively, chlorogenic acid (CGA) and p-coumaroyl quinate. Real time PCR experiments demonstrated an increase in the expression level of HQT in UV-C treated leaves, and established a correlation between the synthesis of phenolic acids and protection against damage due to abiotic stress. The HQT gene, together with a gene encoding hydroxycinnamoyl-CoA:shikimate/quinate hydroxycinnamoyltransferase (HCT) previously isolated from globe artichoke, have been incorporated within the developing globe artichoke linkage maps.

Conclusion: A novel acyltransferase involved in the biosynthesis of CGA in globe artichoke has been isolated, characterized and mapped. This is a good basis for our effort to understand the genetic basis of phenylpropanoid (PP) biosynthesis in C. cardunculus.

Show MeSH
Related in: MedlinePlus