Oxylipin pathway to jasmonates: biochemistry and biological significance

Hámberg, Mats; Gardner, Harold W.

doi:10.1016/0005-2760(92)90069-8

Cited by 244 publications

(150 citation statements)

References 212 publications

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“…For instance, methyl jasmonate (MeJA) is a fragrant compound initially identified from flowers of Jasminum grandiflorum (3), and that is ubiquitously distributed in the plant kingdom (4). MeJA and its free acid jasmonic acid (JA), collectively referred to as jasmonates, are important cellular regulators mediating diverse developmental processes, such as seed germination, flower and fruit development, leaf abscission, and senescence (5).…”

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Jasmonic acid carboxyl methyltransferase: A key enzyme for jasmonate-regulated plant responses

Seo

Song

Cheong

et al. 2001

Proc. Natl. Acad. Sci. U.S.A.

668

457

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Methyl jasmonate is a plant volatile that acts as an important cellular regulator mediating diverse developmental processes and defense responses. We have cloned the novel gene JMT encoding an S-adenosyl-L-methionine:jasmonic acid carboxyl methyltransferase (JMT) from Arabidopsis thaliana. Recombinant JMT protein expressed in Escherichia coli catalyzed the formation of methyl jasmonate from jasmonic acid with K m value of 38.5 M. JMT RNA was not detected in young seedlings but was detected in rosettes, cauline leaves, and developing flowers. In addition, expression of the gene was induced both locally and systemically by wounding or methyl jasmonate treatment. This result suggests that JMT can perceive and respond to local and systemic signals generated by external stimuli, and that the signals may include methyl jasmonate itself. Transgenic Arabidopsis overexpressing JMT had a 3-fold elevated level of endogenous methyl jasmonate without altering jasmonic acid content. The transgenic plants exhibited constitutive expression of jasmonate-responsive genes, including VSP and PDF1.2. Furthermore, the transgenic plants showed enhanced level of resistance against the virulent fungus Botrytis cinerea. Thus, our data suggest that the jasmonic acid carboxyl methyltransferase is a key enzyme for jasmonate-regulated plant responses. Activation of JMT expression leads to production of methyl jasmonate that could act as an intracellular regulator, a diffusible intercellular signal transducer, and an airborne signal mediating intra-and interplant communications.

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“…In addition, a cytoplasmic pathway has also been described (13). JA is then catabolized further to form its volatile counterpart MeJA and numerous conjugates (4).…”

mentioning

confidence: 99%

Jasmonic acid carboxyl methyltransferase: A key enzyme for jasmonate-regulated plant responses

Seo

Song

Cheong

et al. 2001

Proc. Natl. Acad. Sci. U.S.A.

668

457

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“…2 Although allene oxide has not proven to be an intermediate in the prostaglandin synthesis pathway (5), it may be linked to prostanoid type products such as clavulones and punaglandins of other corals (2,6,7). Allene oxides are very unstable epoxides; they readily hydrolyze into ketols, cyclopentenones, and other rearrangement products (8)(9)(10).…”

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Characterization of the Coral Allene Oxide Synthase Active Site with UV−Visible Absorption, Magnetic Circular Dichroism, and Electron Paramagnetic Resonance Spectroscopy: Evidence for Tyrosinate Ligation to the Ferric Enzyme Heme Iron

et al. 2001

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Coral allene oxide synthase (AOS), a hemoprotein with weak sequence homology to catalase, is the N-terminal domain of a naturally occurring fusion protein with an 8R-lipoxygenase. AOS converts 8R-hydroperoxyeicosatetraenoic acid to the corresponding allene oxide. The UV-visible absorption and magnetic circular dichroism spectra of ferric AOS and of its cyanide and azide complexes, and the electron paramagnetic resonance spectra of native AOS (high-spin, g ) 6.56, 5.22, 2.00) and of its cyanide adduct (low-spin, g ) 2.86, 2.24, 1.60) closely resemble the corresponding spectra of bovine liver catalase (BLC). These results provide strong evidence for tyrosinate ligation to the heme iron of AOS as has been established for catalases. On the other hand, the positive circular dichroism bands in the Soret region for all three derivatives of ferric AOS are almost the mirror image of those in catalase. In addition, the cyanide affinity of native AOS (K d ) 10 mM at pH 7) is about 3 orders of magnitude lower than that of BLC. Thus, while these results conclusively support a common tyrosinate-ligated heme in AOS as in catalase, significant differences exist in the interaction between their respective heme prosthetic groups and protein environments, and in the access of small molecules to the heme iron.Interest in the enzymology underlying the high prostaglandin content of the Caribbean sea whip coral, Plexaura homomalla, has been the impetus for several biochemical investigations. Arachidonic acid is metabolized in extracts of P. homomalla and related corals by a lipoxygenase (LOX) 1 pathway that appeared initially to relate to the production of cyclopentenone prostaglandins (1, 2). An 8R-lipoxygenase converts arachidonic acid to 8R-hydroperoxyeicosatetraenoic acid (8R-HPETE), and the fatty acid hydroperoxide is then enzymatically dehydrated to an allene oxide, an epoxide with a propensity to cyclize to cyclopentenone derivatives. Brash et al., in 1997, isolated the cDNA of an 8R-lipoxygenase from P. homomalla and found it to occur with an extra sequence in the open reading frame that encodes the allene oxide synthase (AOS) (3). This natural fusion protein in coral consists of a LOX C-terminal domain (79 kDa) and an AOS N-terminal domain (43 kDa). The truncated (AOS) construct catalyzes an identical reaction to the AOS domain in the fusion protein, converting 8R-HPETE solely to the allene oxide. The truncated construct exhibits very high turnover number (1400/s) (4), although, due to the weaker expression of the fusion protein in E. coli, the comparable values for the fusion protein remain to be determined. 2 Although allene oxide has not proven to be an intermediate in the prostaglandin synthesis pathway (5), it may be linked to prostanoid type products such as clavulones and punaglandins of other corals (2,6,7). Allene oxides are very unstable epoxides; they readily hydrolyze into ketols, cyclopentenones, and other rearrangement products (8-10).The production of allene oxides from fatty acid hydroperoxides also ...

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“…One of the most thoroughly studied mediators is JA. JA appears to play an important role in developmental processes such as flowering, tuberization, fruit ripening, storage, and tendril coiling (Hamberg and Gardner, 1992;Sembdner and Parthier, 1993). Furthermore, JA has attracted much attention because of its structural and biosynthetic similarity to the arachidonic acid-derived signals of the prostaglandin and leukotriene type in animals, suggesting a possible functional analogy in host defense reactions (Vick and Zimmerman, 1983;Bergey et al, 1996).…”

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Induction of 12-Oxo-Phytodienoic Acid in Wounded Plants and Elicited Plant Cell Cultures

Parchmann¹,

Gundlach²,

Mueller³

1997

Plant Physiology

128

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Jasmonic acid (jA) is rapidly biosynthesized from a-linolenic acid in plants upon contact with pathogens or wounding, and triggers gene activation, leading to the synthesis of defensive secondary metabolites and proteins. Despite the recent finding that its precursor, 1 2-0x0-phytodienoic acid (PDA), is a more powerful inducer of gene activation, interest has focused so far almost exclusively on jA.A validated negative chemical ionization-gas chromatography-mass spectrometry method has been developed that allows the simultaneous quantification of endogenous 1 2-0x0-PDA and JA in plant tissues. In six out of eight plant species tested maximal levels of 12-0x0-PDA exceeded peak levels of JA by approximately 3-to 5-fold after elicitation with a yeast cell wall preparation or when plants were wounded. These experiments support the hypothesis that 12-0x0-PDA acts as the predominant jasmonate signal in most plants, whereas JA remains an active metabolite of its precursor. Furthermore, JA but not 12-0x0-PDA was shown to be secreted into the medium from cultured plant cells, suggesting that jA may also act as an intercellular signal.

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Oxylipin pathway to jasmonates: biochemistry and biological significance

Cited by 244 publications

References 212 publications

Jasmonic acid carboxyl methyltransferase: A key enzyme for jasmonate-regulated plant responses

Jasmonic acid carboxyl methyltransferase: A key enzyme for jasmonate-regulated plant responses

Characterization of the Coral Allene Oxide Synthase Active Site with UV−Visible Absorption, Magnetic Circular Dichroism, and Electron Paramagnetic Resonance Spectroscopy: Evidence for Tyrosinate Ligation to the Ferric Enzyme Heme Iron

Induction of 12-Oxo-Phytodienoic Acid in Wounded Plants and Elicited Plant Cell Cultures

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