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 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.

Expression of allene oxide synthase and allene oxide cyclase in the interactions between pea and fungal pathogens

2003 ◽  
Vol 69 (6) ◽  
pp. 351-357 ◽  
Author(s):  
Yasuhiro Ishiga ◽  
Yoshishige Inagaki ◽  
Kazuhiro Toyoda ◽  
Tomonori Shiraishi ◽  
Yuki Ichinose
Keyword(s):  
Fungal Pathogens ◽  
Allene Oxide ◽  
Allene Oxide Synthase ◽  
Allene Oxide Cyclase ◽  
Oxide Synthase

scholarly journals Allene oxide synthase, allene oxide cyclase and jasmonic acid levels in Lotus japonicus nodules

PLoS ONE ◽  
2018 ◽  
Vol 13 (1) ◽  
pp. e0190884 ◽  
Author(s):  
Anna Zdyb ◽  
Marco G. Salgado ◽  
Kirill N. Demchenko ◽  
Wolfram G. Brenner ◽  
Małgorzata Płaszczyca ◽  
...  
Keyword(s):  
Jasmonic Acid ◽  
Lotus Japonicus ◽  
Allene Oxide ◽  
Allene Oxide Synthase ◽  
Allene Oxide Cyclase ◽  
Oxide Synthase

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 Identification of Jasmonic Acid Biosynthetic Genes in Sweet Cherry and Expression Analysis in Four Ancient Varieties from Tuscany

2019 ◽  
Vol 20 (14) ◽  
pp. 3569 ◽  
Author(s):  
Roberto Berni ◽  
Giampiero Cai ◽  
Xuan Xu ◽  
Jean-Francois Hausman ◽  
Gea Guerriero
Keyword(s):  
Jasmonic Acid ◽  
Sweet Cherry ◽  
Allene Oxide ◽  
Allene Oxide Synthase ◽  
Allene Oxide Cyclase ◽  
Sweet Cherries ◽  
Genes Encoding ◽  
Oxide Synthase ◽  
Ja Signaling ◽  
The Impact

Sweet cherries are non-climacteric fruits whose early development is characterized by high levels of the phytohormone jasmonic acid (JA). Important parameters, such as firmness and susceptibility to cracking, can be affected by pre- and postharvest treatments of sweet cherries with JA. Despite the impact of JA on sweet cherry development and fruit characteristics, there are no studies (to the best of our knowledge) identifying the genes involved in the JA biosynthetic pathway in this species. We herein identify the sweet cherry members of the lipoxygenase family (13-LOX); allene oxide synthase, allene oxide cyclase and 12-oxo-phytodienoic acid reductase 3, as well as genes encoding the transcriptional master regulator MYC2. We analyze their expression pattern in four non-commercial Tuscan varieties (‘Carlotta’, ‘Maggiola’, ‘Morellona’, ‘Crognola’) having different levels of bioactives (namely phenolics). The highest differences are found in two genes encoding 13-LOX in the variety ‘Maggiola’ and one MYC2 isoform in ‘Morellona’. No statistically-significant variations are instead present in the allene oxide synthase, allene oxide cyclase and 12-oxo-phytodienoic acid reductase 3. Our data pave the way to follow-up studies on the JA signaling pathway in these ancient varieties, for example in relation to development and post-harvest storage.

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>.

Sign in / Sign up

Export Citation Format

Share Document