1
|
Dhingra S, Zhang Z, Lohans CT, Brewitz L, Schofield CJ. Substitution of 2-oxoglutarate alters reaction outcomes of the Pseudomonas savastanoi ethylene-forming enzyme. J Biol Chem 2024; 300:107546. [PMID: 38992435 PMCID: PMC11345546 DOI: 10.1016/j.jbc.2024.107546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2024] [Revised: 06/27/2024] [Accepted: 07/01/2024] [Indexed: 07/13/2024] Open
Abstract
In seeding plants, biosynthesis of the phytohormone ethylene, which regulates processes including fruit ripening and senescence, is catalyzed by 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase. The plant pathogen Pseudomonas savastanoi (previously classified as: Pseudomonas syringae) employs a different type of ethylene-forming enzyme (psEFE), though from the same structural superfamily as ACC oxidase, to catalyze ethylene formation from 2-oxoglutarate (2OG) in an arginine dependent manner. psEFE also catalyzes the more typical oxidation of arginine to give L-Δ1-pyrroline-5-carboxylate (P5C), a reaction coupled to oxidative decarboxylation of 2OG giving succinate and CO2. We report on the effects of C3 and/or C4 substituted 2OG derivatives on the reaction modes of psEFE. 1H NMR assays, including using the pure shift method, reveal that, within our limits of detection, none of the tested 2OG derivatives is converted to an alkene; some are converted to the corresponding β-hydroxypropionate or succinate derivatives, with only the latter being coupled to arginine oxidation. The NMR results reveal that the nature of 2OG derivatization can affect the outcome of the bifurcating reaction, with some 2OG derivatives exclusively favoring the arginine oxidation pathway. Given that some of the tested 2OG derivatives are natural products, the results are of potential biological relevance. There are also opportunities for therapeutic or biocatalytic regulation of the outcomes of reactions catalyzed by 2OG-dependent oxygenases by the use of 2OG derivatives.
Collapse
Affiliation(s)
- Siddhant Dhingra
- Chemistry Research Laboratory, Department of Chemistry and the Ineos Oxford Institute for Antimicrobial Research, University of Oxford, Oxford, United Kingdom
| | - Zhihong Zhang
- Chemistry Research Laboratory, Department of Chemistry and the Ineos Oxford Institute for Antimicrobial Research, University of Oxford, Oxford, United Kingdom
| | - Christopher T Lohans
- Chemistry Research Laboratory, Department of Chemistry and the Ineos Oxford Institute for Antimicrobial Research, University of Oxford, Oxford, United Kingdom
| | - Lennart Brewitz
- Chemistry Research Laboratory, Department of Chemistry and the Ineos Oxford Institute for Antimicrobial Research, University of Oxford, Oxford, United Kingdom.
| | - Christopher J Schofield
- Chemistry Research Laboratory, Department of Chemistry and the Ineos Oxford Institute for Antimicrobial Research, University of Oxford, Oxford, United Kingdom.
| |
Collapse
|
2
|
Overexpression of Magnaporthe Oryzae Systemic Defense Trigger 1 (MoSDT1) Confers Improved Rice Blast Resistance in Rice. Int J Mol Sci 2019; 20:ijms20194762. [PMID: 31557947 PMCID: PMC6802482 DOI: 10.3390/ijms20194762] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 09/21/2019] [Accepted: 09/24/2019] [Indexed: 12/20/2022] Open
Abstract
The effector proteins secreted by a pathogen not only promote virulence and infection of the pathogen, but also trigger plant defense response. Therefore, these proteins could be used as important genetic resources for transgenic improvement of plant disease resistance. Magnaporthe oryzae systemic defense trigger 1 (MoSDT1) is an effector protein. In this study, we compared the agronomic traits and blast disease resistance between wild type (WT) and MoSDT1 overexpressing lines in rice. Under control conditions, MoSDT1 transgenic lines increased the number of tillers without affecting kernel morphology. In addition, MoSDT1 transgenic lines conferred improved blast resistance, with significant effects on the activation of callose deposition, reactive oxygen species (ROS) accumulation and cell death. On the one hand, overexpression of MoSDT1 could delay biotrophy-necrotrophy switch through regulating the expression of biotrophy-associated secreted protein 4 (BAS4) and Magnaporthe oryzaecell death inducing protein 1 (MoCDIP1), and activate plant defense response by regulating the expression of Bsr-d1, MYBS1, WRKY45, peroxidase (POD), heat shock protein 90 (HSP90), allenoxide synthase 2 (AOS2), phenylalanine ammonia lyase (PAL), pathogenesis-related protein 1a (PR1a) in rice. On the other hand, overexpression of MoSDT1 could increase the accumulation of some defense-related primary metabolites such as two aromatic amino acids (L-tyrosine and L-tryptohan), 1-aminocyclopropane carboxylic acid, which could be converted to ethylene, vanillic acid and L-saccharopine. Taken together, overexpression of MoSDT1 confers improved rice blast resistance in rice, through modulation of callose deposition, ROS accumulation, the expression of defense-related genes, and the accumulation of some primary metabolites.
Collapse
|
3
|
Sato T, Izawa K, Aceña JL, Liu H, Soloshonok VA. Tailor-Made α-Amino Acids in the Pharmaceutical Industry: Synthetic Approaches to (1R,2S)-1-Amino-2-vinylcyclopropane-1-carboxylic Acid (Vinyl-ACCA). European J Org Chem 2016. [DOI: 10.1002/ejoc.201600112] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Tatsunori Sato
- Hamari Chemicals, Ltd.; 1-4-29 Kunijima, Higashi-Yodogawa-ku 533-0024 Osaka Japan
| | - Kunisuke Izawa
- Hamari Chemicals, Ltd.; 1-4-29 Kunijima, Higashi-Yodogawa-ku 533-0024 Osaka Japan
| | - José Luis Aceña
- Department of Organic Chemistry I; Faculty of Chemistry; University of the Basque Country UPV/EHU; Paseo Manuel Lardizábal 3 20018 San Sebastián Spain
- Department of Organic Chemistry; Autónoma University of Madrid; Cantoblanco 28049 Madrid Spain
| | - Hong Liu
- Key Laboratory of Receptor Research; Shanghai Institute of Materia Medica; Chinese Academy of Sciences; 555 Zu Chong Zhi Road 201203 Shanghai P. R. China
| | - Vadim A. Soloshonok
- Department of Organic Chemistry I; Faculty of Chemistry; University of the Basque Country UPV/EHU; Paseo Manuel Lardizábal 3 20018 San Sebastián Spain
- IKERBASQUE; Basque Foundation for Science; Alameda Urquijo 36-5, Plaza Bizkaia 48011 Bilbao Spain
| |
Collapse
|
4
|
Advanced asymmetric synthesis of (1R,2S)-1-amino-2-vinylcyclopropanecarboxylic acid by alkylation/cyclization of newly designed axially chiral Ni(II) complex of glycine Schiff base. Amino Acids 2015; 48:973-986. [DOI: 10.1007/s00726-015-2138-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 11/18/2015] [Indexed: 12/17/2022]
|
5
|
Kawashima A, Xie C, Mei H, Takeda R, Kawamura A, Sato T, Moriwaki H, Izawa K, Han J, Aceña JL, Soloshonok VA. Asymmetric synthesis of (1R,2S)-1-amino-2-vinylcyclopropanecarboxylic acid by sequential SN2–SN2′ dialkylation of (R)-N-(benzyl)proline-derived glycine Schiff base Ni(ii) complex. RSC Adv 2015. [DOI: 10.1039/c4ra12658k] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The synthesis of the title compound, a key structural fragment of several hepatitis C virus inhibitors, is described.
Collapse
Affiliation(s)
| | - Chen Xie
- School of Chemistry and Chemical Engineering
- Nanjing University
- Nanjing
- China
| | - Haibo Mei
- School of Chemistry and Chemical Engineering
- Nanjing University
- Nanjing
- China
| | | | | | | | | | | | - Jianlin Han
- School of Chemistry and Chemical Engineering
- Nanjing University
- Nanjing
- China
| | - José Luis Aceña
- Department of Organic Chemistry I
- Faculty of Chemistry
- University of The Basque Country UPV/EHU
- Spain
| | - Vadim A. Soloshonok
- Department of Organic Chemistry I
- Faculty of Chemistry
- University of The Basque Country UPV/EHU
- Spain
- IKERBASQUE
| |
Collapse
|
6
|
Bousquet JF, Thimann KV. Lipid peroxidation forms ethylene from 1-aminocyclopropane-1-carboxylic acid and may operate in leaf senescence. Proc Natl Acad Sci U S A 2010; 81:1724-7. [PMID: 16593436 PMCID: PMC344991 DOI: 10.1073/pnas.81.6.1724] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
An enzyme system is described which oxidizes 1-aminocyclopropane-1-carboxylic acid (ACC) to ethylene under physiological conditions. It comprises linoleic acid, pyridoxal phosphate, manganese, and lipoxygenase (linoleate:oxygen oxidoreductase, EC 1.13.11.12). It requires oxygen and is specific for manganese; it can operate but only with greatly reduced yield in the absence of pyridoxal phosphate. An enzyme with the same properties was prepared from microsomal membranes of the seedling shoots of peas. Both have similar reactions to a variety of inhibitors and other reagents. The properties also resemble those of at least two of the in vivo systems recorded in the literature. Intact green oat leaves also contain a similar system. Because there is a growing body of evidence that ethylene formation is associated with cell membranes and because the yields of ethylene from the complete system are much higher than those recorded for other enzymes, it may be identical with the in vivo system acting in senescent leaves.
Collapse
Affiliation(s)
- J F Bousquet
- Thimann Laboratories, University of California, Santa Cruz, CA 95064
| | | |
Collapse
|
7
|
Brackmann F, de Meijere A. Natural Occurrence, Syntheses, and Applications of Cyclopropyl-Group-Containing α-Amino Acids. 1. 1-Aminocyclopropanecarboxylic Acid and Other 2,3-Methanoamino Acids. Chem Rev 2007; 107:4493-537. [DOI: 10.1021/cr078376j] [Citation(s) in RCA: 208] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Farina Brackmann
- Institut für Organische und Biomolekulare Chemie der Georg-August-Universität Göttingen, Tammannstrasse 2, 37077 Göttingen, Germany
| | - Armin de Meijere
- Institut für Organische und Biomolekulare Chemie der Georg-August-Universität Göttingen, Tammannstrasse 2, 37077 Göttingen, Germany
| |
Collapse
|
8
|
Manning K. Detoxification of cyanide by plants and hormone action. CIBA FOUNDATION SYMPOSIUM 2007; 140:92-110. [PMID: 3073064 DOI: 10.1002/9780470513712.ch7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
In higher plants cyanide is a co-product of ethylene synthesis. The increase in ethylene production that occurs during the senescence of certain flowers and the ripening of climacteric fruit is accompanied by a rise in beta-cyanoalanine synthase activity. Although these events correlate temporally and spatially, the potential for cyanide detoxification in these tissues is high compared with the expected rate of cyanide formation from the ethylene pathway. However, in stigmas and styles of Petunia flowers a semi-quantitative relationship exists between the activity of beta-cyanoalanine synthase and the activity of ACC (1-aminocyclopropane-1-carboxylic acid) oxidase, the last enzyme in the ethylene pathway. To account for these observations it is proposed that ACC oxidase can react with other amino acids by a general mechanism that liberates cyanide. This hypothesis could also account for the substrate stereospecificity of ACC oxidase, for the extreme lability of this enzyme and for the high accumulation of asparagine in some tissues.
Collapse
Affiliation(s)
- K Manning
- Institute of Horticultural Research, Littlehampton, West Sussex, UK
| |
Collapse
|
9
|
Oudeyer S, Léonel E, Paugam JP, Sulpice-Gaillet C, Nédélec JY. Formation of polysubstituted chlorocyclopropanes from electrophilic olefins and activated trichloromethyl compounds. Tetrahedron 2006. [DOI: 10.1016/j.tet.2005.11.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
10
|
Zhang Z, Ren JS, Clifton IJ, Schofield CJ. Crystal Structure and Mechanistic Implications of 1-Aminocyclopropane-1-Carboxylic Acid Oxidase—The Ethylene-Forming Enzyme. ACTA ACUST UNITED AC 2004; 11:1383-94. [PMID: 15489165 DOI: 10.1016/j.chembiol.2004.08.012] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2004] [Revised: 07/15/2004] [Accepted: 08/02/2004] [Indexed: 10/26/2022]
Abstract
The final step in the biosynthesis of the plant signaling molecule ethylene is catalyzed by 1-aminocyclopropane-1-carboxylic acid oxidase (ACCO). ACCO requires bicarbonate as an activator and catalyzes the oxidation of ACC to give ethylene, CO2, and HCN. We report crystal structures of ACCO in apo-form (2.1 A resolution) and complexed with Fe(II) (2.55 A) or Co(II) (2.4 A). The active site contains a single Fe(II) ligated by three residues (His177, Asp179, and His234), and it is relatively open compared to those of the 2-oxoglutarate oxygenases. The side chains of Arg175 and Arg244, proposed to be involved in binding bicarbonate, project away from the active site, but conformational changes may allow either or both to enter the active site. The structures will form a basis for future mechanistic and inhibition studies.
Collapse
Affiliation(s)
- Zhihong Zhang
- The Oxford Centre for Molecular Sciences, The Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, Oxford OX1 3TA, United Kingdom
| | | | | | | |
Collapse
|
11
|
Rocklin AM, Kato K, Liu HW, Que L, Lipscomb JD. Mechanistic studies of 1-aminocyclopropane-1-carboxylic acid oxidase: single turnover reaction. J Biol Inorg Chem 2004; 9:171-82. [PMID: 14714198 DOI: 10.1007/s00775-003-0510-3] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2003] [Accepted: 11/12/2003] [Indexed: 10/26/2022]
Abstract
The final step in the biosynthesis of the plant hormone ethylene is catalyzed by the non-heme iron-containing enzyme 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase (ACCO). ACC is oxidized at the expense of O(2) to yield ethylene, HCN, CO(2), and two waters. Continuous turnover of ACCO requires the presence of ascorbate and HCO(3)(-) (or an alternative form), but the roles played by these reagents, the order of substrate addition, and the mechanism of oxygen activation are controversial. Here these issues are addressed by development of the first functional single turnover system for ACCO. It is shown that 0.35 mol ethylene/mol Fe(II)ACCO is produced when the enzyme is combined with ACC and O(2) in the presence of HCO(3)(-) but in the absence of ascorbate. Thus, ascorbate is not required for O(2) activation or product formation. Little product is observed in the absence of HCO(3)(-), demonstrating the essential role of this reagent. By monitoring the EPR spectrum of the sample during single turnover, it is shown that the active site Fe(II) oxidizes to Fe(III) during the single turnover. This suggests that the electrons needed for catalysis can be derived from a fraction of the initial Fe(II)ACCO instead of ascorbate. Addition of ascorbate at 10% of its K(m) value significantly accelerates both iron oxidation and ethylene formation, suggesting a novel high-affinity effector role for this reagent. This role can be partially mimicked by a non-redox-active ascorbate analog. A mechanism is proposed that begins with ACC and O(2) binding, iron oxidation, and one-electron reduction to form a peroxy intermediate. Breakdown of this intermediate, perhaps by HCO(3)(-)-mediated proton transfer, is proposed to yield a high-valent iron species, which is the true oxidizing reagent for the bound ACC.
Collapse
Affiliation(s)
- Amy M Rocklin
- Department of Biochemistry, Molecular Biology, and Biophysics, and Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, MN 55455, USA
| | | | | | | | | |
Collapse
|
12
|
|
13
|
|
14
|
On the role of membrane integrity in the conversion of 1-aminocyclopropane 1-carboxylic acid to ethylene in carnation petals. FEBS Lett 2001. [DOI: 10.1016/0014-5793(84)81033-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
15
|
Charng YY, Chou SJ, Jiaang WT, Chen ST, Yang SF. The catalytic mechanism of 1-aminocyclopropane-1-carboxylic acid oxidase. Arch Biochem Biophys 2001; 385:179-85. [PMID: 11361015 DOI: 10.1006/abbi.2000.2138] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
It has been proposed that 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase catalyzes the oxidation of ACC to ethylene via N-hydroxyl-ACC as an intermediate. However, due to its chemical instability the putative intermediate has never been isolated. Here, we have shown that a purified recombinant ACC oxidase can utilize alpha-aminoisobutyric acid (AIB), an analog of ACC, as an alternative substrate, converting AIB into CO2, acetone, and ammonia. We chemically synthesized the putative intermediate compound, N-hydroxyl-AIB (HAIB), and tested whether it serves as an intermediate in the oxidation of AIB. When [1-(14)C]AIB was incubated with ACC oxidase in the presence of excess unlabeled HAIB as a trap, no labeled HAIB was detected. By comparing the acetone production rates employing HAIB and AIB as substrates, the conversion of HAIB to acetone was found to be much slower than that of using AIB as substrate. Based on these observations, we conclude that ACC oxidase does not catalyze via the N-hydroxylation of its amino acid substrate. ACC oxidase also catalyzes the oxidation of other amino acids, with preference for the D-enantiomers, indicating a stereoselectivity of the enzyme.
Collapse
Affiliation(s)
- Y Y Charng
- Institute of BioAgricultural Sciences, Academia Sinica, Nankang, Taipei, Taiwan.
| | | | | | | | | |
Collapse
|
16
|
Beumer R, Bubert C, Cabrele C, Vielhauer O, Pietzsch M, Reiser O. The synthesis of diastereo- and enantiomerically pure beta-aminocyclopropanecarboxylic acids. J Org Chem 2000; 65:8960-9. [PMID: 11149838 DOI: 10.1021/jo005541l] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The synthesis of diastereo- and enantiomerically pure beta-aminocyclopropanecarboxylic acids (beta-ACCs) is described. Starting from pyrrole, (rac)-4 is readily obtained, which was kinetically resolved by enzymatic hydrolysis. Subsequent oxidation of (-)-4 and deformylation gives rise to the cis-beta-ACC derivative (ent)-9, while (+)-10 was converted to the trans-beta-ACC derivative 8. Both 8 and (ent)-9 and their benzyl esters 13 and 16, being conformationally restricted beta-alanine or gamma-aminobutyric acid (GABA) derivatives, represent useful building blocks for peptides containing unnatural amino acids.
Collapse
Affiliation(s)
- R Beumer
- Department of Organic Chemistry, University of Regensburg, Universitätsstr. 31, D-93053 Regensburg, Germany
| | | | | | | | | | | |
Collapse
|
17
|
Dourtoglou V, Koussissi E. Inhibition of apple 1-aminocyclopropane-1-carboxylic acid oxidase, by cyclopropane-1,1-dicarboxylic acid and trans-2-phenylcyclopropane-1-carboxylic acid. PHYTOCHEMISTRY 2000; 55:203-211. [PMID: 11142843 DOI: 10.1016/s0031-9422(00)00315-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Cyclopropane-1,1-dicarboxylic acid (CDA) and trans-2-phenylcyclopropane-1-carboxylic acid (PCCA) are the main representatives of a group of compounds that are structural analogues of 1-aminocyclopropane-1-carboxylic acid (ACC) and have been proved to have an inhibitory effect on the wound ethylene produced by Lycopersicum esculentum fruit discs. During the experiments, that were carried out in this work the inhibition pattern of PCCA and CDA were studied when tested on partially purified apple ACO and their Ki values were determined. A mechanistic proposal was given, in order to explain the kinetic behaviour of the inhibitors. The common feature of these molecules is their cyclopropane ring, with different substitutes mainly at the positions C1 and C2. Two other compounds with similar structure where also tested as inhibitors, in order to clarify the relationship between structure and activity. These compounds are: 2-methyl cyclopropanecarboxylic acid (MCA), and cyclopropanecarboxylic acid (CCA).
Collapse
Affiliation(s)
- V Dourtoglou
- Vioryl S.A. Chemical and Agricultural Industry, Kifissia, Athens, Greece.
| | | |
Collapse
|
18
|
|
19
|
Rocklin AM, Tierney DL, Kofman V, Brunhuber NM, Hoffman BM, Christoffersen RE, Reich NO, Lipscomb JD, Que L. Role of the nonheme Fe(II) center in the biosynthesis of the plant hormone ethylene. Proc Natl Acad Sci U S A 1999; 96:7905-9. [PMID: 10393920 PMCID: PMC22160 DOI: 10.1073/pnas.96.14.7905] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The final step of ethylene biosynthesis in plants is catalyzed by the enzyme 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase (ACCO). In addition to ACC, Fe(II), O2, CO2, and ascorbate are required for in vitro enzyme activity. Direct evidence for the role of the Fe(II) center in the recombinant avocado ACCO has now been obtained through formation of enzyme.(substrate or cofactor).NO complexes. These NO adducts convert the normally EPR-silent ACCO complexes into EPR-active species with structural properties similar to those of the corresponding O2 complexes. It is shown here that the ternary Fe(II)ACCO.ACC.NO complex is readily formed, but no Fe(II)ACCO.ascorbate.NO complex could be observed, suggesting that ascorbate and NO are mutually exclusive in the active site. The binding modes of ACC and the structural analog alanine specifically labeled with 15N or 17O were examined by using Q-band electron nuclear double resonance (ENDOR). The data indicate that these molecules bind directly to the iron through both the alpha-amino and alpha-carboxylate groups. These observations are inconsistent with the currently favored mechanism for ACCO, in which it is proposed that both ascorbate and O2 bind to the iron as a step in O2 activation. We propose a different mechanism in which the iron serves instead to simultaneously bind ACC and O2, thereby fixing their relative orientations and promoting electron transfer between them to initiate catalysis.
Collapse
Affiliation(s)
- A M Rocklin
- Departments of Chemistry and Biochemistry, Molecular Biology and Biophysics and Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, MN 55455, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Control of ethylene synthesis and metabolism. BIOCHEMISTRY AND MOLECULAR BIOLOGY OF PLANT HORMONES 1999. [DOI: 10.1016/s0167-7306(08)60489-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
21
|
De Kimpe N, Boeykens M, Tourwé D. Synthesis of 3,3-dimethylazetidine-2-carboxylic acid and some derivatives. Tetrahedron 1998. [DOI: 10.1016/s0040-4020(98)00024-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
22
|
A straightforward synthesis of both enantiomers of allo-norcoronamic acids and allo-coronamic acids, by asymmetric Strecker reaction from alkylcyclopropanone acetals. ACTA ACUST UNITED AC 1998. [DOI: 10.1016/s0957-4166(97)00633-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
23
|
Jiménez J, Rifé J, Ortuño RM. Enantioselective total syntheses of cyclopropane amino acids: Natural products and protein methanologs. ACTA ACUST UNITED AC 1996. [DOI: 10.1016/0957-4166(96)00038-9] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
24
|
Gilchrist DG, Bostock RM, Wang H. Sphingosine-related mycotoxins in plant and animal diseases. ACTA ACUST UNITED AC 1995. [DOI: 10.1139/b95-283] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The AAL-toxins and fumonisins are a group of chemically related phytotoxic congeners produced by Alternaria alternata f. sp. lycopersici and Fusarium moniliforme, respectively, that also are widespread mycotoxins with important health implications. These mycotoxins, which bear a structural relationship to the sphingoid base, sphingosine, also incite maladies in animals ranging from neoplasms to renal, neural, and hepatic necrosis. A. alternata f. sp. lycopersici causes the Alternaria stem canker disease in tomatoes, while F. moniliforme causes pink ear rot of maize and is associated with post-harvest contamination of many different food staples. These toxins are potent inhibitors of ceramide synthase in plants and animals. Sphingoid bases are mediators of signal transduction leading to neoplasms and necrosis in animals. Significant inhibition of ceramide synthase in microsomal preparations of tomato occurs at 20 nM with an I50in the range of 35–40 nM for both AAL-toxin, TA, and fumonisin, FB1. In plants, specific alterations of physiological processes associated with cellular response to these toxins appears to be required for cell death. A net decrease in sucrose influx to treated leaves occurs within 4 h of AAL-toxin treatment. Untreated leaves of toxin-resistant and -sensitive isolines of tomato show significant differences in sucrose transport capacity. Exogenous application of sucrose transport inhibitors mimicked AAL-toxin symptoms and enhanced cell death in susceptible lines of tomato. Conversely, the accumulation of the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACQ occurred in 1 h and increased rapidly during the next 6 h after exposure to AAL-toxin. ACC accumulation is followed by a burst in ethylene within 12 h. Application of specific inhibitors of ethylene synthesis or ethylene action results in a decrease in toxin-induced cell death. These toxins appear to be useful tools for defining biochemical and molecular features common to induced cell death in both plants and animals. Key words: AAL-toxins, fumonisins, mycotoxins, host-selective toxins, Alternaria stem canker, Alternaria alternata, Fusarium moniliforme.
Collapse
|
25
|
Cativiela C, Díaz-de-Villegas MD, Jiménez AI. A straightforward synthesis of (−)-(1S,2R)-Allonorcoronamic acid using D-mannitol as the chiral source. ACTA ACUST UNITED AC 1995. [DOI: 10.1016/0957-4166(95)00269-u] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
26
|
Enantioselective total syntheses of (−)-allo-coronamic acid, (−)-(Z)-2,3-methanohomoserine, and (2S,3R)-Cbz-cyclo-Asp-OMe. ACTA ACUST UNITED AC 1995. [DOI: 10.1016/0957-4166(95)00234-g] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
27
|
Zhang Z, Schofield CJ, Baldwin JE, Thomas P, John P. Expression, purification and characterization of 1-aminocyclopropane-1-carboxylate oxidase from tomato in Escherichia coli. Biochem J 1995; 307 ( Pt 1):77-85. [PMID: 7717997 PMCID: PMC1136747 DOI: 10.1042/bj3070077] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
1-Aminocyclopropane-1-carboxylate (ACC) oxidase catalyses the final step in the biosynthesis of the plant hormone ethylene. The successful overexpression and characterization of active ACC oxidase from tomato has been achieved. PCR was used to insert the corrected cDNA coding for the tomato ACC oxidase into the pET-11a expression vector. Cloning of the resultant construct in Escherichia coli BL21(DE3)pLysE gave transformants which expressed ACC oxidase at levels greater than 30% of soluble protein under optimized conditions. When induced by addition of isopropyl-beta-D-thiogalactopyranoside (IPTG) at 37 degrees C the ACC oxidase expressed was less soluble and less active than when induced at 27 degrees C. The enzyme was purified to near homogeneity by a three-step chromatographic procedure. The specific activity of the purified recombinant ACC oxidase was typically 1.3-1.9 mol of ethylene/mol of enzyme per min, higher than values reported for native enzyme. Like the native enzyme it displayed a requirement for ferrous iron and ascorbate, and CO2 was an activator. The ability to discriminate between racemic diastereomers of 1-amino-2-ethyl cyclopropane-1-carboxylic acid was demonstrated. The enzyme was found to have a loose specificity for ascorbate, showing apparent preference for D-ascorbate and 5,6-O-isopropylidene L-ascorbate rather than L-ascorbate. The addition of catalase, dithiothreitol and BSA to incubation mixtures all resulted in significant increases in activity. When treated with diethylpyrocarbonate (DEPC) under mildly acidic conditions, the enzyme rapidly lost activity. Comparison of the rate of inactivation with the increase in absorbance at 240 nm gave results consistent with the modification of two to three histidine residues at the active site, although the possibility of additional modification of other nucleophilic residues cannot be excluded. Inactivation was largely prevented by the addition of substrates and ferrous iron, implying that DEPC treatment results in the modification of active-site histidines, which act as ligands for ferrous iron. CO2 offered no protection against DEPC inactivation, either in the absence or presence of substrates and/or ferrous iron.
Collapse
Affiliation(s)
- Z Zhang
- Oxford Centre for Molecular Sciences, U.K
| | | | | | | | | |
Collapse
|
28
|
Cativiela C, Díaz-de-Villegas MD, Jiménez AI. A simple synthesis of (−)-(1S,2R)-allocoronamic acid in its enantiomerically pure form. ACTA ACUST UNITED AC 1995. [DOI: 10.1016/0957-4166(94)00373-j] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
29
|
Asymmetric syntheses of 1-amino-2-phenyl(alkyl)cyclopropanecarboxylic acids by diastereoselective cyclopropanation of highly functionalized monochiral olefines. Tetrahedron 1994. [DOI: 10.1016/s0040-4020(01)89550-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
30
|
Affiliation(s)
- H Fukuda
- Department of Applied Microbial Technology, Kumamoto Institute of Technology, Japan
| | | | | |
Collapse
|
31
|
Alcaraz C, Herrero A, Marco JL, Fernández-Alvarez E, Bernabé M. Enantioselective synthesis of (+)-(1R,2S)-allocoronamic acid. Tetrahedron Lett 1992. [DOI: 10.1016/s0040-4039(00)61159-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
|
32
|
Fernández-Maculet JC, Yang SF. Extraction and partial characterization of the ethylene-forming enzyme from apple fruit. PLANT PHYSIOLOGY 1992; 99:751-4. [PMID: 16668949 PMCID: PMC1080528 DOI: 10.1104/pp.99.2.751] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Ethylene-forming enzyme (EFE) was isolated from apple (Malus domestica Borkh. cv Golden Delicious) fruit tissue. The enzyme activity in the homogenate is associated with the pellet fraction and can be solubilized with Triton X-100 or polyvinylpolypyrrolidone. The solubilized enzyme system resembles the in vivo system in that it exhibits a low K(m) (17 micromolar) for its substrate 1-aminocyclopropane-1-carboxylic acid (ACC), is stereospecific toward 2-ethyl-ACC stereoisomers for 1-butene production, and is inhibited by cobalt ions and alpha-aminoisobutyric acid. Intact preclimacteric fruits treated with exogenous ethylene showed a marked increase in in vivo EFE activity and this increase was accompanied by a parallel increase in in vitro EFE activity. These results support the notion that the isolated EFE represents the authentic in vivo activity.
Collapse
Affiliation(s)
- J C Fernández-Maculet
- Mann Laboratory, Department of Vegetable Crops, University of California, Davis, California 95616
| | | |
Collapse
|
33
|
Groth U, Halfbrodt W, Schöllkopf U. Asymmetric Synthesis via Heterocyclic Intermediates, XLVII. Asymmetric Synthesis of (+)-(1R,2S)-allo-Coronamic Acid. ACTA ACUST UNITED AC 1992. [DOI: 10.1002/jlac.199219920162] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
34
|
Rusconi di Lugano F, Monteiro J, Fliche C, Braun J, Le Goffic F. An Enantioselective Chemoenzymatic Synthesis of the Four 1-Amino 2-Methylcyclopropane Carboxylic Acids. SYNTHETIC COMMUN 1992. [DOI: 10.1080/00397919208021100] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
35
|
McGarvey D, Christoffersen R. Characterization and kinetic parameters of ethylene-forming enzyme from avocado fruit. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(18)42649-x] [Citation(s) in RCA: 87] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
|
36
|
Marco JL, Sánchez B, Fernández MD, Bernabé M. Synthesis ofrac-allocoronamic acid hydrochloride. ACTA ACUST UNITED AC 1991. [DOI: 10.1002/jlac.1991199101190] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
37
|
Hamilton AJ, Bouzayen M, Grierson D. Identification of a tomato gene for the ethylene-forming enzyme by expression in yeast. Proc Natl Acad Sci U S A 1991; 88:7434-7. [PMID: 1714605 PMCID: PMC52310 DOI: 10.1073/pnas.88.16.7434] [Citation(s) in RCA: 136] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The ethylene-forming enzyme (EFE), which catalyzes the last step in the biosynthesis of the plant hormone ethylene, has never been purified and no molecular probes are available. Recently, a putative cDNA clone for tomato EFE (pTOM13) has been identified by inhibiting ethylene synthesis with an antisense gene expressed in transgenic plants. A direct test of its function has been made by expression of a pTOM13 gene in Saccharomyces cerevisiae. After cloning artefacts were discovered in the 5' region of the cDNA, a corrected cDNA (pRC13) was created by the fusion of the 5' end of a genomic clone to the 3' end of the cDNA and expressed in S. cerevisiae. Cultures of transformed yeast converted 1-aminocyclopropane-1-carboxylic acid (ACC) to ethylene, whereas control cells did not. This EFE activity displays similar characteristics to EFE found in plant tissue: it converts the trans isomer of the ACC analogue 1-amino-2-ethylcyclopropane-1-carboxylic acid to 1-butene in preference to the cis isomer, and it is strongly inhibited by cobaltous ions and 1,10-phenanthroline. Furthermore, information gained from the activity of effectors on yeast EFE activity supports the hypothesis that EFE is one of a group of hydroxylase enzymes.
Collapse
Affiliation(s)
- A J Hamilton
- Department of Physiology and Environmental Science, University of Nottingham School of Agriculture, Sutton Bonington, Loughborough, United Kingdom
| | | | | |
Collapse
|
38
|
Alami A, Calmes M, Daunis J, Escale F, Jacquier R, Roumestant ML, Viallefont P. Asymmetric synthesis of cis and trans 2-methyl and 2-ethyl 1-amino cyclopropanecarboxylic acids. ACTA ACUST UNITED AC 1991. [DOI: 10.1016/s0957-4166(00)82352-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
39
|
Van Der Straeten D, Van Montagu M. The molecular basis of ethylene biosynthesis, mode of action, and effects in higher plants. Subcell Biochem 1991; 17:279-326. [PMID: 1796487 DOI: 10.1007/978-1-4613-9365-8_13] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
|
40
|
|
41
|
Bouzayen M, Latché A, Pech JC. Subcellular localization of the sites of conversion of 1-aminocyclopropane-1-carboxylic acid into ethylene in plant cells. PLANTA 1990; 180:175-180. [PMID: 24201941 DOI: 10.1007/bf00193992] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/28/1989] [Indexed: 06/02/2023]
Abstract
The subcellular localization of the sites of 1-aminocyclopropane-1-carboxylic acid (ACC) conversion into ethylene was studied by comparing the specific radioactivity of ethylene evolved from the whole cells with that of intra- and extracellular pools of labelled ACC. We demonstrate that some cells cultured in vitro (Vitis vinifera L. cv. Muscat) or leaf tissues (Hordeum vulgare L. and Triticum aestivum L.) have two sites of ethylene production: (i) an external site, converting apoplastic ACC, located at the plasma membrane, and very sensitive to high osmotica and, (ii) an intracellular site, converting internal ACC and remaining unaffected even under severe plasmolysis. In other cells cultured in vitro (Vitis vinifera L. cv. Gamay) and pea leaves (Pisum sativum L.), only the intracellular site operates and ethylene production is almost unaffected by plasmolysis. Protoplasts obtained from plasmolysis-sensitive Muscat cells lose 97% of their capacity for ethylene production compared with the parent cell, while those from plasmolysisinsensitive Gamay cells retain up to 50%. Protoplasts from both Gamay and Muscat cells cultured for 8 d in vitro, recover the full capacity of ethylene production of the initial whole cells, whether or not they are allowed to reform their cell wall. Therefore, we exclude a cooperation between the cell wall and the plasma membrane in ethylene production.
Collapse
Affiliation(s)
- M Bouzayen
- Ecole Nationale Supérieure Agronomique, 145, avenue de Muret, F-31076, Toulouse Cédex, France
| | | | | |
Collapse
|
42
|
Pirrung MC, Dunlap SE, Trinks UP. Ethylene Biosynthesis part 10. Synthesis and study of racemic, (1R, 2S)-, and (1S, 2R)-1-Amino-2-(hydroxymethyl)cyclopropanecarboxylic Acid. Helv Chim Acta 1989. [DOI: 10.1002/hlca.19890720618] [Citation(s) in RCA: 67] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
43
|
Abstract
The properties of enzymes involved in ethylene biosynthesis are reviewed and progress toward the purification of these enzymes is described. The enzyme whose activity usually limits ethylene biosynthesis is 1-aminocyclopropane-1-carboxylate (ACC) synthase. Even though its level in plants is extremely low, it has now been purified from several sources. The enzyme that converts ACC to ethylene does not survive homogenization, apparently because it is membrane-bound and because its activity requires membrane integrity. Properties of this enzyme have been elucidated in vivo and in vacuolar preparations which possess the capacity to convert ACC to ethylene.
Collapse
Affiliation(s)
- H Kende
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
| |
Collapse
|
44
|
De Kimpe N, Sulmon P, Schamp N. Synthesis of 2,2-dimethyl-1-aminocyclopropanecarboxylic acid from β-chloroimines. Tetrahedron Lett 1989. [DOI: 10.1016/s0040-4039(01)80573-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
45
|
|
46
|
Wheeler TN, Ray JA. A Convenient and Efficient Synthesis of 1-Aminocyclopropanecarboxylic Acid (ACC). SYNTHETIC COMMUN 1988. [DOI: 10.1080/00397918808077338] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
47
|
Okamoto T, Shimada M, Oka S. Ethylene Formation from 1-Aminocyclopropanecarboxylic Acid by the Reaction of Molecular Oxygen and Dihydropyridine Mediated by Flavin Mononucleotide and Mn(II) Ion. CHEM LETT 1987. [DOI: 10.1246/cl.1987.817] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
48
|
Wang TT, Yang SF. The physiological role of lipoxygenase in ethylene formation from 1-aminocyclopropane-1-carboxylic acid in oat leaves. PLANTA 1987; 170:190-196. [PMID: 24232877 DOI: 10.1007/bf00397887] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/1986] [Accepted: 11/12/1986] [Indexed: 06/02/2023]
Abstract
In order to understand the physiological significance of the in-vitro lipoxygenase (EC 1.13.11.12)-mediated ethylene-forming system (J.F. Bousquet and K.V. Thimann 1984, Proc. Natl. Acad. Sci. USA 81, 1724-1727), its characteristics were compared to those of an in-vivo ethylene-forming system. While oat (Avena sativa L.) leaves, as other plant tissues, preferentially converted only one of the 1-amino-2-ethylcyclopropane-1-carboxylic acid (AEC) isomers to 1-butene, the lipoxygenase system converted all four AEC isomers to 1-butene with nearly equal efficiencies. While the in-vivo ethylene-forming system of oat leaves was saturable with ACC with a Km of 16 μM, the lipoxygenase system was not saturated with ACC even at 10 mM. In contrast to the in-vivo results, only 10% of the ACC consumed in the lipoxygenase system was converted to ethylene, indicating that the reaction is not specific for ethylene formation. Increased ACC-dependent ethylene production in oat leaves following pretreatment with linoleic acid has been inferred as evidence of the involvement of lipoxygenase in ethylene production. We found that pretreating oat leaves with linoleic acid resulted in increased ACC uptake and thereby increased ethylene production. A similar effect was observed with oleic acid, which is not a substrate of lipoxygenase. Since linoleic acid hydroperoxide can substitute for lipoxygenase and linoleic acid in this system, it is assumed that the alkoxy radicals generated during the decomposion of linoleic acid hydroperoxide are responsible for the degradation of ACC to ethylene. Our results collectively indicate that the reported lipoxygenase system is not the in-vivo ethylene-forming enzyme.
Collapse
Affiliation(s)
- T T Wang
- Department of Vegetable Crops, University of California, 95616, Davis, CA, USA
| | | |
Collapse
|
49
|
|
50
|
Adam Z, Mayak S. Age-Dependent Discrimination between Stereoisomers of 1-Amino-2-Ethylcyclopropane-1-Carboxylic Acid in Carnation Petals. PLANT PHYSIOLOGY 1986; 80:1045-7. [PMID: 16664717 PMCID: PMC1075254 DOI: 10.1104/pp.80.4.1045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The ability of carnation petals (Dianthus caryophyllus L. cv White Sim) of different ages to convert the cis and trans isomers of 1-amino-2-ethylcyclopropane-1-carboxylic acid (AEC) to 1-butene was studied. Young petals, which produce ethylene at a low rate, convert both cis- and trans-AEC to 1-butene with low efficiency and at equal rates. In senescing petals, the rate of conversion of cis-AEC remains low, but there is a marked increase in the rate of trans-AEC conversion. Thus there is a clear evidence of stereodiscrimination between the isomers. Stimulating the rate of senescence by treatment with either 1-aminocyclopropane-1-carboxylic acid or ethylene further increases the rate of trans-AEC conversion. Delaying of petal senescence by silver thiosulphate or aminooxyacetic acid inhibits the rise in trans-AEC conversion.
Collapse
Affiliation(s)
- Z Adam
- Department of Ornamental Horticulture, The Hebrew University of Jerusalem, Rehovot 76100, Israel
| | | |
Collapse
|