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Griesser M, Hoffmann T, Bellido ML, Rosati C, Fink B, Kurtzer R, Aharoni A, Muñoz-Blanco J, Schwab W. Redirection of flavonoid biosynthesis through the down-regulation of an anthocyanidin glucosyltransferase in ripening strawberry fruit. PLANT PHYSIOLOGY 2008; 146:1528-39. [PMID: 18258692 PMCID: PMC2287331 DOI: 10.1104/pp.107.114280] [Citation(s) in RCA: 115] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2007] [Accepted: 01/21/2008] [Indexed: 05/18/2023]
Abstract
Strawberry (Fragaria x ananassa) fruit contains several anthocyanins that give the ripe fruits their attractive red color. The enzyme that catalyzes the formation of the first stable intermediate in the anthocyanin pathway is anthocyanidin-3-O-glucosyltransferase. A putative glycosyltransferase sequence (FaGT1) was cloned from a strawberry fruit cDNA library and the recombinant FaGT1 transferred UDP-glucose to anthocyanidins and, to a lesser extent, flavonols, generating the respective 3-O-glucosides. Quantitative polymerase chain reaction revealed that transcripts of FaGT1 were almost undetectable in green fruits, but gene expression increased dramatically in both turning and ripe red fruit, corresponding closely to the accumulation of anthocyanins during fruit ripening. The expression of FaGT1 is fruit associated and negatively regulated by auxin. To elucidate the in planta function of FaGT1, Agrobacterium tumefaciens cells harboring an intron-hairpin construct of a partial FaGT1 sequence were injected into midsized ripening fruits. In about one-third of the injected fruits, this led to significant down-regulation of FaGT1 transcript levels that corresponded to reduced concentrations of anthocyanin pigments in ripe strawberry fruits. In contrast, significant levels of epiafzelechin--formed by anthocyanidin reductase (ANR) from pelargonidin--were identified in FaGT1-silenced fruits, indicating competition of FaGT1 and FaANR for the common anthocyanidin substrate. Thus, FaGT1 represents an important branching-point enzyme because it is channeling the flavonoid pathway to anthocyanins. These results demonstrate a method to redirect the anthocyanin biosynthesis into flavan-3-ol production to increase the levels of bioactive natural products or modify pigments in plant tissues.
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Affiliation(s)
- Markus Griesser
- Biomolecular Food Technology, Technical University Munich, 85354 Freising, Germany
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52
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Griesser M, Vitzthum F, Fink B, Bellido ML, Raasch C, Munoz-Blanco J, Schwab W. Multi-substrate flavonol O-glucosyltransferases from strawberry (Fragaria x ananassa) achene and receptacle. JOURNAL OF EXPERIMENTAL BOTANY 2008; 59:2611-25. [PMID: 18487633 PMCID: PMC2486459 DOI: 10.1093/jxb/ern117] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2008] [Accepted: 04/02/2008] [Indexed: 05/18/2023]
Abstract
In an effort to characterize fruit ripening-related genes functionally, two glucosyltransferases, FaGT6 and FaGT7, were cloned from a strawberry (Fragaria x ananassa) cDNA library and the full-length open reading frames were amplified by rapid amplification of cDNA ends. FaGT6 and FaGT7 were expressed heterologously as fusion proteins in Escherichia coli and target protein was purified using affinity chromatography. Both recombinant enzymes exhibited a broad substrate tolerance in vitro, accepting numerous flavonoids, hydroxycoumarins, and naphthols. FaGT6 formed 3-O-glucosides and minor amounts of 7-O-, 4'-O-, and 3'-O-monoglucosides and one diglucoside from flavonols such as quercetin. FaGT7 converted quercetin to the 3-O-glucoside and 4'-O-glucoside and minor levels of the 7- and 3'-isomers but formed no diglucoside. Gene expression studies showed that both genes are strongly expressed in achenes of small-sized green fruits, while the expression levels were generally lower in the receptacle. Significant levels of quercetin 3-O-, 7-O-, and 4'-O-glucosides, kaempferol 3-O- and 7-O-glucosides, as well as isorhamnetin 7-O-glucoside, were identified in achenes and the receptacle. In the receptacle, the expression of both genes is negatively controlled by auxin which correlates with the ripening-related gene expression in this tissue. Salicylic acid, a known signal molecule in plant defence, induces the expression of both genes. Thus, it appears that FaGT6 and FaGT7 are involved in the glucosylation of flavonols and may also participate in xenobiotic metabolism. The latter function is supported by the proven ability of strawberries to glucosylate selected unnatural substrates injected in ripe fruits. This report presents the first biochemical characterization of enzymes mainly expressed in strawberry achenes and provides the foundation of flavonoid metabolism in the seeds.
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Affiliation(s)
- Markus Griesser
- Biomolecular Food Technology, Technical University Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany
| | - Florian Vitzthum
- Biomolecular Food Technology, Technical University Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany
| | - Barbara Fink
- Biomolecular Food Technology, Technical University Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany
| | - Mari Luz Bellido
- Departamento de Bioquímica y Biología Molecular, Edificio Severo Ochoa (C-6), Campus Universitario de Rabanales, Universidad de Córdoba, 14071 Córdoba, Spain
| | - Constanze Raasch
- Biomolecular Food Technology, Technical University Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany
| | - Juan Munoz-Blanco
- Departamento de Bioquímica y Biología Molecular, Edificio Severo Ochoa (C-6), Campus Universitario de Rabanales, Universidad de Córdoba, 14071 Córdoba, Spain
| | - Wilfried Schwab
- Biomolecular Food Technology, Technical University Munich, Lise-Meitner-Str. 34, 85354 Freising, Germany
- To whom correspondence should be addressed. E-mail:
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53
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Ma LQ, Liu BY, Gao DY, Pang XB, Lü SY, Yu HS, Wang H, Yan F, Li ZQ, Li YF, Ye HC. Molecular cloning and overexpression of a novel UDP-glucosyltransferase elevating salidroside levels in Rhodiola sachalinensis. PLANT CELL REPORTS 2007; 26:989-99. [PMID: 17333022 DOI: 10.1007/s00299-007-0317-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2006] [Revised: 02/07/2007] [Accepted: 02/08/2007] [Indexed: 05/14/2023]
Abstract
Salidroside is a novel effective adaptogenic drug extracted from the medicinal plant Rhodiola sachalinensis A. Bor. Because this plant is a rare resource and has low yield, there is great interest in enhancing the production of salidroside. In this study, a putative UDP-glucosyltransferase (UGT) cDNA, UGT73B6, was isolated from Rhodiola sachalinensis using a rapid amplification of cDNA ends (RACE) method. The cDNA was 1,598 bp in length encoding 480 deduced amino acid residues with a conserved UDP-glucose-binding domain (PSPG box). Southern blot analysis of genomic DNA indicated that UGT73B6 existed as a single copy gene in the R. sachalinensis genome. Northern blot analysis revealed that transcripts of UGT73B6 were present in roots, calli and stems, but not in leaves. The UGT73B6 under 35S promoter with double-enhancer sequences from CaMV-Omega and TMV-Omega fragments was transferred into R. sachalinensis via Agrobacterium tumefaciens. PCR, PCR-Southern and Southern blot analyses confirmed that the UGT73B6 gene had been integrated into the genome of transgenic calli and plants. Northern blot analysis revealed that the UGT73B6 gene had been expressed at the transcriptional level. High performance liquid chromatography (HPLC) analysis indicated that the overexpression of the UGT73B6 gene resulted in an evident increase of salidroside content. These data suggest that the cloned UGT73B6 can regulate the conversion of tyrosol aglycon to salidroside in R. sachalinensis. This is the first cloned glucosyltransferase gene involved in salidroside biosynthesis.
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Affiliation(s)
- Lan-Qing Ma
- Key Laboratory of Photosynthesis and Environmental Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, People's Republic of China
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54
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Miller KD, Weaver-Feldhaus J, Gray SA, Siegel RW, Feldhaus MJ. Production, purification, and characterization of human scFv antibodies expressed in Saccharomyces cerevisiae, Pichia pastoris, and Escherichia coli. Protein Expr Purif 2006; 42:255-67. [PMID: 15946857 DOI: 10.1016/j.pep.2005.04.015] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2004] [Revised: 04/21/2005] [Accepted: 04/25/2005] [Indexed: 10/25/2022]
Abstract
Single chain (scFv) antibodies are used as affinity reagents for diagnostics, therapeutics, and proteomic analyses. The antibody discovery platform we use to identify novel antigen binders involves discovery, characterization, and production. The discovery and characterization components have previously been characterized but in order to fully utilize the capabilities of affinity reagents from our yeast surface display library, efforts were focused on developing a production component to obtain purified, soluble, and active scFvs. Instead of optimizing conditions to achieve maximum yield, efforts were focused on using a system that could quickly and easily produce and process hundreds of scFv antibodies. Heterologous protein expression in Saccharomyces cerevisiae, Pichia pastoris, and Escherichia coli were evaluated for their ability to rapidly, efficaciously, and consistently produce scFv antibodies for use in downstream proteomic applications. Following purification, the binding activity of several scFv antibodies were quantified using a novel Biacore assay. All three systems produced soluble scFv antibodies which ranged in activity from 0 to 99%. scFv antibody yields from Saccharomyces, Pichia, and E. coli were 1.5-4.2, 0.4-7.3, and 0.63-16.4 mgL(-1) culture, respectively. For our purposes, expression in E. coli proved to be the quickest and most consistent way to obtain and characterize purified scFv for downstream applications. The E. coli expression system was subsequently used to study three scFv variants engineered to determine structure-function relationships.
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Affiliation(s)
- Keith D Miller
- Pacific Northwest National Laboratory, 902 Battelle Boulevard, P.O. Box 999, Richland, WA 99352, USA
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55
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Abstract
Glycosyltransferases (GTs) are ubiquitous enzymes that catalyze the transfer of a sugar moiety from an activated donor to an acceptor and thus play important roles in natural product biogenesis, virulence, and biomolecular recognition. Sugars are often critical for bioactivity of natural products, and methodologies for creating diverse glycoforms of these compounds are highly desirable. A recent study demonstrates that several GTs involved in natural product biosynthesis catalyze reversible reactions. Sugar exchange and aglycon exchange strategies were used to exploit this reversibility to generate >70 calicheamicin analogues.
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Affiliation(s)
- Charles E Melançon
- Department of Chemistry and Biochemistry, College of Pharmacy, University of Texas at Austin, Austin, Texas 78712, USA
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56
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He XZ, Wang X, Dixon RA. Mutational analysis of the Medicago glycosyltransferase UGT71G1 reveals residues that control regioselectivity for (iso)flavonoid glycosylation. J Biol Chem 2006; 281:34441-7. [PMID: 16982612 DOI: 10.1074/jbc.m605767200] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The plant glycosyltransferase UGT71G1 from the model legume barrel medic (Medicago truncatula) glycosylates flavonoids, isoflavonoids, and triterpenes. It can transfer glucose to each of the five hydroxyl groups of the flavonol quercetin, with the 3'-O-glucoside as the major product, and to the A-ring 7-hydroxyl of the isoflavone genistein. The sugar donor and acceptor binding pockets are located in the N and C termini, respectively, of the recently determined crystal structure of UGT71G1. The residues forming the binding pockets of UGT71G1 were systematically altered by site-directed mutagenesis. Mutation of Phe148 to Val, or Tyr202 to Ala, drastically changed the regioselectivity for quercetin glycosylation from predominantly the 3'-O-position of the B-ring to the 3-O-position of the C ring. The Y202A mutant exhibited comparable catalytic efficiency with quercetin to the wild-type enzyme, whereas efficiency was reduced 3-4-fold in the F148V mutant. The Y202A mutant gained the ability to glycosylate the 5-hydroxyl of genistein. Additional mutations affected the relative specificities for the sugar donors UDP-galactose and UDP-glucuronic acid, although UDP-glucose was always preferred. The results are discussed in relation to the design of novel biocatalysts for production of therapeutic flavonoids.
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Affiliation(s)
- Xian-Zhi He
- Plant Biology Division, Samuel Roberts Noble Foundation, Ardmore, Oklahoma 73401, USA
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57
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Zhang C, Griffith BR, Fu Q, Albermann C, Fu X, Lee IK, Li L, Thorson JS. Exploiting the reversibility of natural product glycosyltransferase-catalyzed reactions. Science 2006; 313:1291-4. [PMID: 16946071 DOI: 10.1126/science.1130028] [Citation(s) in RCA: 243] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Glycosyltransferases (GTs), an essential class of ubiquitous enzymes, are generally perceived as unidirectional catalysts. In contrast, we report that four glycosyltransferases from two distinct natural product biosynthetic pathways-calicheamicin and vancomycin-readily catalyze reversible reactions, allowing sugars and aglycons to be exchanged with ease. As proof of the broader applicability of these new reactions, more than 70 differentially glycosylated calicheamicin and vancomycin variants are reported. This study suggests the reversibility of GT-catalyzed reactions may be general and useful for generating exotic nucleotide sugars, establishing in vitro GT activity in complex systems, and enhancing natural product diversity.
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Affiliation(s)
- Changsheng Zhang
- Laboratory for Biosynthetic Chemistry, Pharmaceutical Sciences Division, School of Pharmacy, National Cooperative Drug Discovery Group Program, University of Wisconsin (UW)-Madison, 777 Highland Avenue, Madison, WI 53705-2222, USA
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58
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Routaboul JM, Kerhoas L, Debeaujon I, Pourcel L, Caboche M, Einhorn J, Lepiniec L. Flavonoid diversity and biosynthesis in seed of Arabidopsis thaliana. PLANTA 2006; 224:96-107. [PMID: 16395586 DOI: 10.1007/s00425-005-0197-5] [Citation(s) in RCA: 185] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2005] [Accepted: 11/25/2005] [Indexed: 05/03/2023]
Abstract
Functional characterization of genes involved in the flavonoid metabolism and its regulation requires in-depth analysis of flavonoid structure and composition of seed from the model plant Arabidopsis thaliana. Here, we report an analysis of the diverse and specific flavonoids that accumulate during seed development and maturation in wild types and mutants. Wild type seed contained more than 26 different flavonoids belonging to flavonols (mono and diglycosylated quercetin, kaempferol and isorhamnetin derivatives) and flavan-3-ols (epicatechin monomers and soluble procyanidin polymers with degrees of polymerization up to 9). Most of them are described for the first time in Arabidopsis. Interestingly, a novel group of four biflavonols that are dimers of quercetin-rhamnoside was also detected. Quercetin-3-O-rhamnoside (the major flavonoid), biflavonols, epicatechin and procyanidins accumulated in the seed coat in contrast to diglycosylated flavonols that were essentially observed in the embryo. Epicatechin, procyanidins and an additional quercetin-rhamnoside-hexoside derivative were synthesized in large quantities during seed development, whereas quercetin-3-O-rhamnoside displayed two peaks of accumulation. Finally, 11 mutants affected in known structural or regulatory functions of the pathway and their three corresponding wild types were also studied. Flavonoid profiles of the mutants were consistent with previous predictions based on genetic and molecular data. In addition, they also revealed the presence of new products in seed and underlined the plasticity of this metabolic pathway in the mutants.
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Affiliation(s)
- Jean-Marc Routaboul
- Laboratoire de Biologie des Semences, UMR 204 INRA-INAPG, Institut Jean-Pierre Bourgin, 78026 Versailles Cedex, France.
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59
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Bowles D, Lim EK, Poppenberger B, Vaistij FE. Glycosyltransferases of lipophilic small molecules. ANNUAL REVIEW OF PLANT BIOLOGY 2006; 57:567-97. [PMID: 16669774 DOI: 10.1146/annurev.arplant.57.032905.105429] [Citation(s) in RCA: 315] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Glycosyltransferases of small molecules transfer sugars to a wide range of acceptors, from hormones and secondary metabolites to biotic and abiotic chemicals and toxins in the environment. The enzymes are encoded by large multigene families and can be identified by a signature motif in their primary sequence, which classifies them as a subset of Family 1 glycosyltransferases. The transfer of a sugar onto a lipophilic acceptor changes its chemical properties, alters its bioactivity, and enables access to membrane transporter systems. In vitro studies have shown that a single gene product can glycosylate multiple substrates of diverse origins; multiple enzymes can also glycosylate the same substrate. These features suggest that in a cellular context, substrate availability is a determining factor in enzyme function, and redundancy depends on the extent of coordinate gene regulation. This review discusses the role of these glycosyltransferases in underpinning developmental and metabolic plasticity during adaptive responses.
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Affiliation(s)
- Dianna Bowles
- Center for Novel Agricultural Products, Department of Biology, University of York, York YO10 5DD, United Kingdom.
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60
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Taylor LP, Grotewold E. Flavonoids as developmental regulators. CURRENT OPINION IN PLANT BIOLOGY 2005; 8:317-23. [PMID: 15860429 DOI: 10.1016/j.pbi.2005.03.005] [Citation(s) in RCA: 326] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
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61
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Lim EK, Ashford DA, Hou B, Jackson RG, Bowles DJ. Arabidopsis glycosyltransferases as biocatalysts in fermentation for regioselective synthesis of diverse quercetin glucosides. Biotechnol Bioeng 2005; 87:623-31. [PMID: 15352060 DOI: 10.1002/bit.20154] [Citation(s) in RCA: 184] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Regioselectivity of glycosyltransferases offers an important means to overcome the limitations of chemical synthesis of small molecule glycosides. In this study we explore a large multigene family of UDP-glucose:glycosyltransferases of Arabidopsis for their potential as novel biocatalysts for in vitro synthesis and whole-cell catalysis. We used quercetin as a substrate for this study because the flavonol and its glycosides have important medicinal properties and the metabolite provides a complex structure for regioselective glucosylation. We analyzed the activity of 91 recombinant enzymes for in vitro activity toward quercetin and discovered 29 that are capable of glucosylating the substrate. We demonstrate the first enzymic synthesis of a range of glucosides in vitro, including the 3-O-, 7-O-, 3'-O-, and 4'-O-monoglucosides, 3,7-di-O-glucoside, and 7,3'-di-O-glucoside. We also show that the regioselectivity of glucosylation can be maintained when the enzymes are used as whole-cell biocatalysts in Escherichia coli.
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Affiliation(s)
- Eng-Kiat Lim
- Department of Biology, CNAP, Heslington, University of York, York, North Yorkshire YO10 5DD, United Kingdom
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62
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Moraga AR, Nohales PF, Pérez JAF, Gómez-Gómez L. Glucosylation of the saffron apocarotenoid crocetin by a glucosyltransferase isolated from Crocus sativus stigmas. PLANTA 2004; 219:955-966. [PMID: 15605174 DOI: 10.1007/s00425-004-1299-1] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2003] [Accepted: 04/22/2004] [Indexed: 05/24/2023]
Abstract
Saffron, the dry stigma of Crocus sativus L., is considered to be the world's most expensive spice. Three major apocarotenoids--crocin, crocetin and picrocrocin--are responsible for the colour and bitter taste of saffron. The final step in the biosynthesis of the 20-carbon esterified carotenoid crocin is the transformation of the insoluble crocetin into a soluble and stable storage form by glucosylation. These glucosylation reactions are catalysed by glucosyltransferases (GTases) that play a crucial role in natural-product biosynthesis. Using degenerate primers designed to match the plant secondary product GTase (PSPG) box we cloned two cDNAs, UGTCs2 and UGTCs3, from C. sativus stigmas that encode putative polypeptides of 460 and 475 amino acids, respectively. These genes were expressed differentially in saffron tissues. UGTCs2 was mainly expressed in fully developed stigmas, whereas UGTCs3 was mainly expressed in stamens. The UGTCs2 transcript was not detected in the stigma tissue of a Crocus species that does not synthesize crocin, while UGTCs3 and other structural genes for carotenoid biosynthesis were expressed in the stigma of all tested Crocus species. To identify the biochemical function of UGTCs2, the isolated cDNA was expressed in Escherichia coli cells. The recombinant protein UGTCs2 had glucosylation activity against crocetin, crocetin beta-D-glucosyl ester and crocetin beta-D-gentibiosyl ester. These results might suggest that the isolated clone UGTCs2 codes for a saffron crocetin GTase.
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Affiliation(s)
- Angela Rubio Moraga
- Sección de Biotecnología, Instituto de Desarrollo Regional (UCLM), Campus Universitario s/n, 02071 Albacete, Spain
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63
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Kubo A, Arai Y, Nagashima S, Yoshikawa T. Alteration of sugar donor specificities of plant glycosyltransferases by a single point mutation. Arch Biochem Biophys 2004; 429:198-203. [PMID: 15313223 DOI: 10.1016/j.abb.2004.06.021] [Citation(s) in RCA: 110] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2004] [Revised: 06/22/2004] [Indexed: 11/20/2022]
Abstract
In comparison with the amino acid sequences of seven species of glucosyltransferases and six species of galactosyltransferases, glutamine and histidine are highly conserved as the last amino acid residue of a glycosyltransferase-specific conserved region (UDPGT) in glucosyltransferases and galactosyltransferases, respectively. Consequently, the sugar donor specificities of glycosyltransferases are successfully altered by a single amino acid point mutation. UDP-galactose:anthocyanin galactosyltransferase (ACGaT), isolated from Aralia cordata, acquired glucosyltransferase activity in addition to the inherent galactosyltransferase activity by replacing histidine with glutamine. In contrast, UDP-glucose:flavonoid glucosyltransferase (UBGT), isolated from Scutellaria baicalensis, did not acquire galactosyltransferase activity by replacing glutamine with histidine, and exhibited a remarkable decrease in glucosyltransferase activity.
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Affiliation(s)
- Akiko Kubo
- School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641, Japan
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64
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Lim EK, Bowles DJ. A class of plant glycosyltransferases involved in cellular homeostasis. EMBO J 2004; 23:2915-22. [PMID: 15241472 PMCID: PMC514916 DOI: 10.1038/sj.emboj.7600295] [Citation(s) in RCA: 175] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2003] [Accepted: 06/03/2004] [Indexed: 11/08/2022] Open
Abstract
Many small lipophilic compounds in living cells can be modified by glycosylation. These processes can regulate the bioactivity of the compounds, their intracellular location and their metabolism. The glycosyltransferases involved in biotransformations of small molecules have been grouped into Family 1 of the 69 families that are classified on the basis of substrate recognition and sequence relatedness. In plants, these transfer reactions generally use UDP-glucose with acceptors that include hormones such as auxins and cytokinins, secondary metabolites such as flavonoids, and foreign compounds including herbicides and pesticides. In mammalian organisms, UDP-glucuronic acid is typically used in the transfer reactions to endogenous acceptors, such as steroid and thyroid hormones, bile acids and retinoids, and to xenobiotics, including nonsteroidal anti-inflammatory drugs and dietary metabolites. There is widespread interest in this class of enzyme since they are known to function both in the regulation of cellular homeostasis and in detoxification pathways. This review outlines current knowledge of these glycosyltransferases drawing on information gained from studies of plant and mammalian enzymes.
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Affiliation(s)
- Eng-Kiat Lim
- CNAP, Department of Biology, University of York, York, UK
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65
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Jones P, Messner B, Nakajima JI, Schäffner AR, Saito K. UGT73C6 and UGT78D1, glycosyltransferases involved in flavonol glycoside biosynthesis in Arabidopsis thaliana. J Biol Chem 2003; 278:43910-8. [PMID: 12900416 DOI: 10.1074/jbc.m303523200] [Citation(s) in RCA: 237] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Flavonol glycosides constitute one of the most prominent plant natural product classes that accumulate in the model plant Arabidopsis thaliana. To date there are no reports of functionally characterized flavonoid glycosyltransferases in Arabidopsis, despite intensive research efforts aimed at both flavonoids and Arabidopsis. In this study, flavonol glycosyltransferases were considered in a functional genomics approach aimed at revealing genes involved in determining the flavonol-glycoside profile. Candidate glycosyltransferase-encoding genes were selected based on homology to other known flavonoid glycosyltransferases and two T-DNA knockout lines lacking flavonol-3-O-rhamnoside-7-O-rhamnosides (ugt78D1) and quercetin-3-O-rhamnoside-7-O-glucoside (ugt73C6 and ugt78D1) were identified. To confirm the in planta results, cDNAs encoding both UGT78D1 and UGT73C6 were expressed in vitro and analyzed for their qualitative substrate specificity. UGT78D1 catalyzed the transfer of rhamnose from UDP-rhamnose to the 3-OH position of quercetin and kaempferol, whereas UGT73C6 catalyzed the transfer of glucose from UDP-glucose to the 7-OH position of kaempferol-3-O-rhamnoside and quercetin-3-O-rhamnoside, respectively. The present results suggest that UGT78D1 and UGT73C6 should be classified as UDP-rhamnose:flavonol-3-Orhamnosyltransferase and UDP-glucose:flavonol-3-O-glycoside-7-O-glucosyltransferase, respectively.
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Affiliation(s)
- Patrik Jones
- Department of Molecular Biology and Biotechnology, Graduate school of Pharmaceutical Sciences, Chiba University, Core Research for Evolutional Science and Technology of Japan Science and Technology Corporation (JST), Chiba 263-8522, Japan
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66
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Hansen KS, Kristensen C, Tattersall DB, Jones PR, Olsen CE, Bak S, Møller BL. The in vitro substrate regiospecificity of recombinant UGT85B1, the cyanohydrin glucosyltransferase from Sorghum bicolor. PHYTOCHEMISTRY 2003; 64:143-151. [PMID: 12946413 DOI: 10.1016/s0031-9422(03)00261-9] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The in vitro substrate specificity of UDP-glucose:p-hydroxymandelonitrile-O-glucosyltransferase from Sorghum bicolor (UGT85B1) was examined using a range of potential acceptor molecules, including cyanohydrins, terpenoids, phenolics, hexanol derivatives and plant hormones. Qualitative enzyme activity assays employing 20 different putative substrates were performed and 15 proved to be glucosylated using recombinant UGT85B1 isolated from Escherichia coli. K(m) and k(cat) values were determined for nine of these substrates including mandelonitrile, geraniol, nerol and beta-citronellol, 2-hydroxy-3-methoxybenzyl alcohol, 1-hexanol, cis-3-hexen-1-ol, 3-methyl-3-buten-1-ol and 3-methyl-2-buten-1-ol. UGT85B1 has a rather broad substrate specificity in vitro but shows regiospecificity, demanding the presence of a sterically unhindered hydroxyl group e.g. as part of a cyanohydrin function, as a primary alcohol or as a phenolic hydroxyl group and being influenced by the stereochemistry and/or interactive chemistry of the substituents on the hydroxyl-bearing carbon atom.
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Affiliation(s)
- Karina Sinding Hansen
- Plant Biochemistry Laboratory, Department of Plant Biology, Royal Veterinary and Agricultural University, Thorvaldsensvej 40, and Center of Molecular Plant Physiology (PlaCe), DK-1871 Frederiksberg C, Copenhagen, Denmark
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67
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Fukuchi-Mizutani M, Okuhara H, Fukui Y, Nakao M, Katsumoto Y, Yonekura-Sakakibara K, Kusumi T, Hase T, Tanaka Y. Biochemical and molecular characterization of a novel UDP-glucose:anthocyanin 3'-O-glucosyltransferase, a key enzyme for blue anthocyanin biosynthesis, from gentian. PLANT PHYSIOLOGY 2003; 132:1652-63. [PMID: 12857844 PMCID: PMC167102 DOI: 10.1104/pp.102.018242] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Gentian (Gentiana triflora) blue petals predominantly contain an unusually blue and stable anthocyanin, delphinidin 3-O-glucosyl-5-O-(6-O-caffeoyl-glucosyl)-3'-O-(6-O-caffeoyl-glucoside) (gentiodelphin). Glucosylation and the subsequent acylation of the 3'-hydroxy group of the B-ring of anthocyanins are important to the stabilization of and the imparting of bluer color to these anthocyanins. The enzymes and their genes involved in these modifications of the B-ring, however, have not been characterized, purified, or isolated to date. In this study, we purified a UDP-glucose (Glc):anthocyanin 3'-O-glucosyltransferase (3'GT) enzyme to homogeneity from gentian blue petals and isolated a cDNA encoding a 3'GT based on the internal amino acid sequences of the purified 3'GT. The deduced amino acid sequence indicates that 3'GT belongs to the same subfamily as a flavonoid 7-O-glucosyltransferase from Schutellaria baicalensis in the plant glucosyltransferase superfamily. Characterization of the enzymatic properties using the recombinant 3'GT protein revealed that, in contrast to most of flavonoid glucosyltransferases, it has strict substrate specificity: 3'GT specifically glucosylates the 3'-hydroxy group of delphinidin-type anthocyanins containing Glc groups at 3 and 5 positions. The enzyme specifically uses UDP-Glc as the sugar donor. The specificity was confirmed by expression of the 3'GT cDNA in transgenic petunia (Petunia hybrida). This is the first report of the gene isolation of a B-ring-specific glucosyltransferase of anthocyanins, which paves the way to modification of flower color by production of blue anthocyanins.
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Affiliation(s)
- Masako Fukuchi-Mizutani
- Institute for Fundamental Research, Suntory Ltd., 1-1-1 Wakayamadai, Shimamoto-cho, Mishima-gun, Osaka, 618-8503, Japan. Masako_Mizutani@suntory flowers.co.jp
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68
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Taylor LP, Miller KD. The use of a photoactivatable kaempferol analogue to probe the role of flavonol 3-O-galactosyltransferase in pollen germination. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2003; 505:41-50. [PMID: 12083465 DOI: 10.1007/978-1-4757-5235-9_4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
Flavonol induced pollen germination in petunia is rapid, specific, and achieved at low concentrations of kaempferol or quercetin. To determine the macromolecules that interact with the flavonol signal we have synthesized affinity-tagged kaempferol analogues. The first generation molecules are based on a benzophenone photophore. We find that 2-(3-benzoylphenyl)-3,5,7-trihydroxychromen-4-one (BPKae) antagonizes flavonol-induced pollen germination in a concentration-dependent manner. Further, BPKae acts as an irreversible inhibitor of flavonol 3-O-galactosyltransferase (F3GalTase), the gametophyte-specific enzyme that controls the accumulation of glycosylated flavonols in pollen. The effects of BPKae are mediated by UV-A light treatment. The binding characteristics of BPKae to F3GalTase suggest that it can be used to identify the residues required for flavonol-binding and catalysis.
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Affiliation(s)
- Loverine P Taylor
- School of Molecular Biosciences, Washington State University, Pullman WA 99164-4234, USA.
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69
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Ibrahim RK, Anzellotti D. Chapter one The enzymatic basis of flavonoid biodiversity. RECENT ADVANCES IN PHYTOCHEMISTRY 2003. [DOI: 10.1016/s0079-9920(03)80016-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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70
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Lim EK, Doucet CJ, Li Y, Elias L, Worrall D, Spencer SP, Ross J, Bowles DJ. The activity of Arabidopsis glycosyltransferases toward salicylic acid, 4-hydroxybenzoic acid, and other benzoates. J Biol Chem 2002; 277:586-92. [PMID: 11641410 DOI: 10.1074/jbc.m109287200] [Citation(s) in RCA: 196] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Benzoates are a class of natural products containing compounds of industrial and strategic importance. In plants, the compounds exist in free form and as conjugates to a wide range of other metabolites such as glucose, which can be attached to the carboxyl group or to specific hydroxyl groups on the benzene ring. These glucosylation reactions have been studied for many years, but to date only one gene encoding a benzoate glucosyltransferase has been cloned. A phylogenetic analysis of sequences in the Arabidopsis genome revealed a large multigene family of putative glycosyltransferases containing a consensus sequence typically found in enzymes transferring glucose to small molecular weight compounds such as secondary metabolites. Ninety of these sequences have now been expressed as recombinant proteins in Escherichia coli, and their in vitro catalytic activities toward benzoates have been analyzed. The data show that only 14 proteins display activity toward 2-hydroxybenzoic acid, 4-hydroxybenzoic acid, and 3,4-dihydroxybenzoic acid. Of these, only two enzymes are active toward 2-hydroxybenzoic acid, suggesting they are the Arabidopsis salicylic acid glucosyltransferases. All of the enzymes forming glucose esters with the metabolites were located in Group L of the phylogenetic tree, whereas those forming O-glucosides were dispersed among five different groups. Catalytic activities were observed toward glucosylation of the 2-, 3-, or 4-hydroxyl group on the ring. To further explore their regioselectivity, the 14 enzymes were analyzed against benzoic acid, 3-hydroxybenzoic acid, 2,3-, 2,4-, 2,5-, and 2,6-dihydroxybenzoic acid. The data showed that glycosylation of specific sites could be positively or negatively influenced by the presence of additional hydroxyl groups on the ring. This study provides new tools for biotransformation reactions in vitro and a basis for engineering benzoate metabolism in plants.
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Affiliation(s)
- Eng-Kiat Lim
- Centre for Novel Agricultural Products, Department of Biology, University of York, York YO10 SDD, United Kingdom
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71
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Li Y, Baldauf S, Lim EK, Bowles DJ. Phylogenetic analysis of the UDP-glycosyltransferase multigene family of Arabidopsis thaliana. J Biol Chem 2001; 276:4338-43. [PMID: 11042215 DOI: 10.1074/jbc.m007447200] [Citation(s) in RCA: 291] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A class of UDP-glycosyltransferases (UGTs) defined by the presence of a C-terminal consensus sequence is found throughout the plant and animal kingdoms. Whereas mammalian enzymes use UDP-glucuronic acid, the plant enzymes typically use UDP-glucose in the transfer reactions. A diverse array of aglycones can be glucosylated by these UGTs. In plants, the aglycones include plant hormones, secondary metabolites involved in stress and defense responses, and xenobiotics such as herbicides. Glycosylation is known to regulate many properties of the aglycones such as their bioactivity, their solubility, and their transport properties within the cell and throughout the plant. As a means of providing a framework to start to understand the substrate specificities and structure-function relationships of plant UGTs, we have now applied a molecular phylogenetic analysis to the multigene family of 99 UGT sequences in Arabidopsis. We have determined the overall organization and evolutionary relationships among individual members with a surprisingly high degree of confidence. Through constructing a composite phylogenetic tree that also includes all of the additional plant UGTs with known catalytic activities, we can start to predict both the evolutionary history and substrate specificities of new sequences as they are identified. The tree already suggests that while the activities of some subgroups of the UGT family are highly conserved among different plant species, others subgroups shift substrate specificity with relative ease.
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Affiliation(s)
- Y Li
- Department of Biology, University of York, P.O. Box 373, York YO10 5DD, United Kingdom
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72
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Chung HJ, Kim YA, Kim YJ, Choi YK, Hwang YK, Park YS. Purification and characterization of UDP-glucose:tetrahydrobiopterin glucosyltransferase from Synechococcus sp. PCC 7942. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1524:183-8. [PMID: 11113566 DOI: 10.1016/s0304-4165(00)00156-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Tetrahydrobiopterin (BH4)-glucoside was identified from Synechococcus sp. PCC 7942 by HPLC analysis and the enzymatic activity of a glycosyltransferase producing the compound from UDP-glucose and BH4. The novel enzyme, named UDP-glucose:BH4 glucosyltransferase, has been purified 846-fold from the cytosolic fraction of Synechococcus sp. PCC 7942 to apparent homogeneity on SDS-PAGE. The native enzyme exists as a monomer having a molecular mass of 39.2 kDa on SDS-PAGE. The enzyme was active over a broad range of pH from 6.5 to 10.5 but most active at pH 10.0. The enzyme required Mn(2+) for maximal activity. Optimum temperature was 42 degrees C. Apparent K(m) values for BH4 and UDP-glucose were determined as 4.3 microM and 188 microM, respectively, and V(max) values were 16.1 and 15.1 pmol min(-1) mg(-1), respectively. The N-terminal amino acid sequence was Thr-Ala-His-Arg-Phe-Lys-Phe-Val-Ser-Thr-Pro-Val-Gly-, sharing high homology with the predicted N-terminal sequence of an unidentified open reading frame slr1166 determined in the genome of Synechocystis sp. PCC 6803, which is known to produce a pteridine glycoside cyanopterin.
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Affiliation(s)
- H J Chung
- Department of Microbiology, Inje University, 621-749, Kimhae, South Korea
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73
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Tanaka H, Stohlmeyer MM, Wandless TJ, Taylor LP. Synthesis of flavonol derivatives as probes of biological processes. Tetrahedron Lett 2000. [DOI: 10.1016/s0040-4039(00)01767-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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74
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Vogt T, Jones P. Glycosyltransferases in plant natural product synthesis: characterization of a supergene family. TRENDS IN PLANT SCIENCE 2000; 5:380-6. [PMID: 10973093 DOI: 10.1016/s1360-1385(00)01720-9] [Citation(s) in RCA: 398] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Glycosyltransferases of plant secondary metabolism transfer nucleotide-diphosphate-activated sugars to low molecular weight substrates. Until recently, glycosyltransferases were thought to have only limited influence on the basic physiology of the plant. This view has changed. Glycosyltransferases might in fact have an important role in plant defense and stress tolerance. Recent results obtained with several recombinant enzymes indicate that many glycosyltransferases are regioselective or regiospecific rather than highly substrate specific. This might indicate how plants evolve novel secondary products, placing enzymes with broad substrate specificities downstream of the conserved, early, pivotal enzymes of plant secondary metabolism.
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Affiliation(s)
- T Vogt
- Dept of Plant Secondary Metabolism, Leibniz Institute for Plant Biochemistry, 06120 Halle/Saale, Weinberg 3, Germany.
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75
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Guyon VN, Astwood JD, Garner EC, Dunker AK, Taylor LP. Isolation and characterization of cDNAs expressed in the early stages of flavonol-induced pollen germination in petunia. PLANT PHYSIOLOGY 2000; 123:699-710. [PMID: 10859200 PMCID: PMC59038 DOI: 10.1104/pp.123.2.699] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Petunia (Petunia hybrida) pollen requires flavonols (Fl) to germinate. Adding kaempferol to Fl-deficient pollen causes rapid and synchronous germination and tube outgrowth. We exploited this system to identify genes responsive to Fls and to examine the changes in gene expression that occur during the first 0.5 h of pollen germination. We used a subtracted library and differential screening to identify 22 petunia germinating pollen clones. All but two were expressed exclusively in pollen and half of the clones were rare or low abundance cDNAs. RNA gel-blot analysis showed that the steady-state transcript levels of all the clones were increased in response to kaempferol. The sequences showing the greatest response to kaempferol encode proteins that have regulatory or signaling functions and include S/D4, a leucine-rich repeat protein, S/D1, a LIM-domain protein, and D14, a putative Zn finger protein with a heme-binding site. Eight of the clones were novel including S/D10, a cDNA only expressed very late in pollen development and highly up-regulated during the first 0.5 h of germination. The translation product of the S/D3 cDNA shares some features with a neuropeptide that regulates guidance and growth in the tips of extending axons. This study confirmed that the bulk of pollen mRNA accumulates well before germination, but that specific sequences are transcribed during the earliest moments of Fl-induced pollen germination.
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Affiliation(s)
- V N Guyon
- School of Molecular Biosciences, Washington State University, Pullman 99163-4234, USA
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