scholarly journals The lipoxygenase pathway in tulip (Tulipa gesneriana): detection of the ketol route

2000 ◽  
Vol 352 (2) ◽  
pp. 501-509 ◽  
Author(s):  
Alexander N. GRECHKIN ◽  
Lucia S. MUKHTAROVA ◽  
Mats HAMBERG
Keyword(s):  
Octadecadienoic Acid ◽  
Optical Purity ◽  
Cyclase Activity ◽  
Allene Oxide ◽  
Allene Oxide Synthase ◽  
Lipoxygenase Pathway ◽  
Tulipa Gesneriana ◽  
Tulip Bulbs ◽  
Oxide Synthase

The in vitro metabolism of [1-14C]linoleate, [1-14C]linolenate and their 9(S)-hydroperoxides was studied in cell-free preparations from tulip (Tulipa gesneriana) bulbs, leaves and flowers. Linoleate and its 9-hydroperoxide were converted by bulb and leaf preparations into three ketols: (12Z)-9-hydroxy-10-oxo-12-octadecadienoic acid (α-ketol), (11E)-10-oxo-13-hydroxy-11-octadecadienoic acid (γ-ketol) and a novel compound, (12Z)-10-oxo-11-hydroxy-12-octadecadienoic acid (10,11-ketol), in the approximate molar proportions of 10:3:1. The corresponding 15,16-dehydro α- and γ-ketols were the main metabolites of [1-14C]linolenate and its 9-hydroperoxide. Thus bulbs and leaves possessed 9-lipoxygenase and allene oxide synthase activities. Incubations with flower preparations gave α-ketol hydro(pero)xides as predominant metabolites. Bulb and leaf preparations possessed a novel enzyme activity, γ-ketol reductase, which reduces γ-ketol to 10-oxo-13-hydroxyoctadecanoic acid (dihydro-γ-ketol) in the presence of NADH. Exogenous linolenate 13(S)-hydroperoxide was converted mostly into chiral (9S,13S)-12-oxo-10-phytodienoate (99.5% optical purity) by bulb preparations, while [1-14C]linolenate was a precursor for ketols only. Thus tulip bulbs possess abundant allene oxide cyclase activity, the substrate for which is linolenate 13(S)-hydroperoxide, even though 13(S)-lipoxygenase products were not detectable in the bulbs. The majority of the cyclase activity was found in the microsomes (105g pellet). Cyclase activity was not found in the other tissues examined, but only in the bulbs. The ketol route of the lipoxygenase pathway, mediated by 9-lipoxygenase and allene oxide synthase activities, has not been detected previously in the vegetative organs of any plant species.

Lipoxygenase pathway in tulip: biosynthesis of ketols

2000 ◽  
Vol 28 (6) ◽  
pp. 851-853 ◽  
Author(s):  
A. N. Grechkin ◽  
L. S. Mukhtarova ◽  
M. Hamberg
Keyword(s):  
Octadecadienoic Acid ◽  
Allene Oxide ◽  
The Novel ◽  
Allene Oxide Synthase ◽  
Allene Oxide Cyclase ◽  
Lipoxygenase Pathway ◽  
Tulipa Gesneriana ◽  
Oxide Synthase

The metabolism in vitro of [1-14C]linoleate, [1-14C]linolenate and their 9(S)-hydroperoxides in tulip (Tulipa gesneriana) was found to be under the control of 9-lipoxygenase and allene oxide synthase, and directed towards α-ketol, γ-ketol and the novel compound (12Z)-10-oxo-11-hydroxy- 12-octadecadienoic acid (10,11-ketol). Potent activity of allene oxide cyclase (in bulbs) and a new enzyme, γ-ketol reductase (in bulbs and leaves), was detected. Metabolism in flowers is directed predominantly towards α-ketol hydroperoxide.

scholarly journals Detection of the First Epoxyalcohol Synthase/Allene Oxide Synthase (CYP74 Clan) in the Lancelet (Branchiostoma belcheri, Chordata)

2021 ◽  
Vol 22 (9) ◽  
pp. 4737
Author(s):  
Yana Y. Toporkova ◽  
Elena O. Smirnova ◽  
Natalia V. Lantsova ◽  
Lucia S. Mukhtarova ◽  
Alexander N. Grechkin
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Oxidative Metabolism ◽  
Octadecadienoic Acid ◽  
Cytochromes P450 ◽  
Allene Oxide ◽  
Allene Oxide Synthase ◽  
Branchiostoma Belcheri ◽  
Oxide Synthase ◽  
Fatty Acid Hydroperoxides

The CYP74 clan cytochromes (P450) are key enzymes of oxidative metabolism of polyunsaturated fatty acids in plants, some Proteobacteria, brown and green algae, and Metazoa. The CYP74 enzymes, including the allene oxide synthases (AOSs), hydroperoxide lyases, divinyl ether synthases, and epoxyalcohol synthases (EASs) transform the fatty acid hydroperoxides to bioactive oxylipins. A novel CYP74 clan enzyme CYP440A18 of the Asian (Belcher’s) lancelet (Branchiostoma belcheri, Chordata) was biochemically characterized in the present work. The recombinant CYP440A18 enzyme was active towards all substrates used: linoleate and α-linolenate 9- and 13-hydroperoxides, as well as with eicosatetraenoate and eicosapentaenoate 15-hydroperoxides. The enzyme specifically converted α-linolenate 13-hydroperoxide (13-HPOT) to the oxiranyl carbinol (9Z,11R,12R,13S,15Z)-11-hydroxy-12,13-epoxy-9,15-octadecadienoic acid (EAS product), α-ketol, 12-oxo-13-hydroxy-9,15-octadecadienoic acid (AOS product), and cis-12-oxo-10,15-phytodienoic acid (AOS product) at a ratio of around 35:5:1. Other hydroperoxides were converted by this enzyme to the analogous products. In contrast to other substrates, the 13-HPOT and 15-HPEPE yielded higher proportions of α-ketols, as well as the small amounts of cyclopentenones, cis-12-oxo-10,15-phytodienoic acid and its higher homologue, dihomo-cis-12-oxo-3,6,10,15-phytotetraenoic acid, respectively. Thus, the CYP440A18 enzyme exhibited dual EAS/AOS activity. The obtained results allowed us to ascribe a name “B. belcheri EAS/AOS” (BbEAS/AOS) to this enzyme. BbEAS/AOS is a first CYP74 clan enzyme of Chordata species possessing AOS activity.

scholarly journals Developing a platform for production of the oxylipin KODA 9-hydroxy-10-oxo-octadecadienoic acid in plants

2021 ◽  
Author(s):  
Yuta Ihara ◽  
Takayuki Wakamatsu ◽  
Mineyuki Yokoyama ◽  
Daisuke Maezawa ◽  
Hiroyuki Ohta ◽  
...  
Keyword(s):  
Crop Production ◽  
Aquatic Plant ◽  
Octadecadienoic Acid ◽  
Ectopic Expression ◽  
Allene Oxide ◽  
Allene Oxide Synthase ◽  
Leaf Extracts ◽  
Oxide Synthase ◽  
Endogenous Lipids

Abstract KODA (9-hydroxy-10-oxo-12(Z),15(Z)-octadecadienoic acid) is a plant oxylipin involved in recovery from stress. As an agrichemical, KODA helps maintain crop production under various environmental stresses. In plants, KODA is synthesized from α-linolenic acids via 9-lipoxygenase (9-LOX) and allene oxide synthase (AOS), although the amount is usually low except in the free-floating aquatic plant Lemna paucicostata. To improve KODA biosynthetic yield in other plants such as Nicotiana benthamiana and Arabidopsis thaliana, we developed a system to overproduce KODA in vivo via ectopic expression of L. paucicostata 9-LOX and AOS. The transient expression in N. benthamiana showed that the expression of these two genes is sufficient to produce KODA in leaves. However, stable expression of 9-LOX and AOS (with consequent KODA production) in Arabidopsis plants succeeded only when the two proteins were localized in plastids or the endoplasmic reticulum/lipid droplets. Although only small amounts of KODA could be detected in leaf extracts of transgenic Nicotiana or Arabidopsis plants, subsequent incubation of the extracts increased KODA abundance over time. Therefore, KODA production in transgenic plants stably expressing 9-LOX and AOS requires specific subcellular localization of these two enzymes and incubation of leaf crude extracts, which liberates α-linolenic acid via breakdown of endogenous lipids.

scholarly journals Wounding stimulates ALLENE OXIDE SYNTHASE gene and increases the level of jasmonic acid in Ipomoea nil cotyledons

2016 ◽  
Vol 85 (1) ◽  
Author(s):  
Emilia Wilmowicz ◽  
Agata Kućko ◽  
Kamil Frankowski ◽  
Barbara Zabrocka-Nowakowska ◽  
Katarzyna Panek ◽  
...  
Keyword(s):  
Jasmonic Acid ◽  
Stress Responses ◽  
Allene Oxide ◽  
Allene Oxide Synthase ◽  
Lipoxygenase Pathway ◽  
Ipomoea Nil ◽  
Evolutionarily Conserved ◽  
Strong Stimulation ◽  
Oxide Synthase

<em>Allene oxide synthase</em> (<em>AOS</em>) encodes the first enzyme in the lipoxygenase pathway, which is responsible for jasmonic acid (JA) formation. In this study we report the molecular cloning and characterization of <em>InAOS</em> from <em>Ipomoea nil</em>. The full-length gene is composed of 1662 bp and encodes for 519 amino acids. The predicted InAOS contains PLN02648 motif, which is evolutionarily conserved and characteristic for functional enzymatic proteins. We have shown that wounding led to a strong stimulation of the examined gene activity in cotyledons and an increase in JA level, which suggest that this compound may be a modulator of stress responses in <em>I. nil</em>.

scholarly journals Poplar Allene Oxide Synthase 1 Gene Promoter Drives Rapid and Localized Expression by Wounding

2021 ◽  
pp. 16-28
Author(s):  
Bin Lei ◽  
Christopher J. Frost ◽  
Tao Xu ◽  
Joshua R. Herr ◽  
John E. Carlson ◽  
...  
Keyword(s):  
Expression Patterns ◽  
Regulation Of Gene Expression ◽  
Gene Promoter ◽  
Allene Oxide ◽  
Allene Oxide Synthase ◽  
Lipoxygenase Pathway ◽  
Binding Motifs ◽  
Inducible Promoters ◽  
Essential Enzyme ◽  
Oxide Synthase

Promoters play critical roles in controlling the transcription of genes and are important as tools to drive heterologous expression for biotechnological applications. In addition to core transcription factor-binding motifs that assist in the binding of RNA polymerases, there are specific nucleotide sequences in a promoter region to allow regulation of gene expression. The allene oxide synthase (AOS) gene family are cytochrome P450s that are responsive to a variety of environmental stress, making them good candidates for the discovery of inducible promoters. Populus AOS homologs separate phylogenetically into two clades. Based on the 19 promoter motifs with significant abundance differences between the two clades, Clade I AOS genes are likely more responsive to hormones, salt, and pathogen, whereas clade II homologs are likely inducible by water stress. In this study, an upstream promoter from a Clade I poplar AOS encoding gene (AOS1) was cloned and used to drive the expression of a ß-glucuronidase (GUS) gene in Arabidopsis. AOS is an essential enzyme in the lipoxygenase pathway that is responsible for the production of many non-volatile oxylipins in plants, including the jasmonates, which are regulatory phytohormones coordinating a variety of biological and stress response functions. Consistent with AOS transcript expression patterns, we found that the poplar AOS1 promoter drives rapid and localized expression by wounding. The study provides insight on the responsive elements in the poplar AOS promoters, but more importantly identifies a strong wound-inducible and localized promoter for future applications.

scholarly journals Specific Adduction of Plant Lipid Transfer Protein by an Allene Oxide Generated by 9-Lipoxygenase and Allene Oxide Synthase

2006 ◽  
Vol 281 (51) ◽  
pp. 38981-38988 ◽  
Author(s):  
Bénédicte Bakan ◽  
Mats Hamberg ◽  
Ludivine Perrocheau ◽  
Daniel Maume ◽  
Hélène Rogniaux ◽  
...  
Keyword(s):  
Lipid Transfer Protein ◽  
Allene Oxide ◽  
Allene Oxide Synthase ◽  
Lipid Transfer ◽  
Plant Lipid ◽  
Transfer Protein ◽  
Oxide Synthase

scholarly journals Functional Characterization of An Allene Oxide Synthase Involved in Biosynthesis of Jasmonic Acid and Its Influence on Metabolite Profiles and Ethylene Formation in Tea (Camellia sinensis) Flowers

2018 ◽  
Vol 19 (8) ◽  
pp. 2440 ◽  
Author(s):  
Qiyuan Peng ◽  
Ying Zhou ◽  
Yinyin Liao ◽  
Lanting Zeng ◽  
Xinlan Xu ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Jasmonic Acid ◽  
Camellia Sinensis ◽  
Allene Oxide ◽  
Allene Oxide Synthase ◽  
Tea Leaves ◽  
Ethylene Formation ◽  
Horticultural Crops ◽  
Metabolite Profiles ◽  
Oxide Synthase

Jasmonic acid (JA) is reportedly involved in the interaction between insects and the vegetative parts of horticultural crops; less attention has, however, been paid to its involvement in the interaction between insects and the floral parts of horticultural crops. Previously, we investigated the allene oxide synthase 2 (AOS2) gene that was found to be the only JA synthesis gene upregulated in tea (Camellia sinensis) flowers exposed to insect (Thrips hawaiiensis (Morgan)) attacks. In our present study, transient expression analysis in Nicotiana benthamiana plants confirmed that CsAOS2 functioned in JA synthesis and was located in the chloroplast membrane. In contrast to tea leaves, the metabolite profiles of tea flowers were not significantly affected by 10 h JA (2.5 mM) treatment as determined using ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry, and gas chromatography-mass spectrometry. Moreover, JA treatment did not significantly influence ethylene formation in tea flowers. These results suggest that JA in tea flowers may have different functions from JA in tea leaves and other flowers.

scholarly journals Jasmonates: what ALLENE OXIDE SYNTHASE does for plants

2019 ◽  
Vol 70 (13) ◽  
pp. 3373-3378 ◽  
Author(s):  
Edward E Farmer ◽  
Alain Goossens
Keyword(s):  
Allene Oxide ◽  
Allene Oxide Synthase ◽  
Oxide Synthase
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