Plant Lipoxygenase: Structure and Function

Siedow, James N.

doi:10.1146/annurev.pp.42.060191.001045

Cited by 695 publications

(436 citation statements)

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“…The expression of/ox genes in plants is developmentally regulated during plant growth (Siedow, 1991). Iox gene expression may also be induced by a series of other factors including hormonal treatment (jasmonic acid and ABA; Vick and Zimmermann, 1987), pathogen attack (Bostock eta/., 1992) and wounding (Geerts eta/., 1994).…”

Section: Discussionmentioning

confidence: 99%

Visualization of differential gene expression using a novel method of RNA fingerprinting based on AFLP: Analysis of gene expression during potato tuber development

Bachem¹,

Hoeven²,

et al. 1996

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SummaryUsing a highly synchronous in vitro tuberization system, in combination with an amplified restriction fragment polymorphism (AFLpt)-derived technique for RNA fingerprinting (cDNA-AFLPt), transcriptional changes at and around the time point of potato tuberization have been analyzed. The targeted expression analysis of a specific transcript coding for the major potato storage protein, patatin and a second transcript, coding for ADP-glucose pyrophosphorylase, a key gene in the starch biosynthetic pathway is described. This paper confirms that kinetics of expression revealed by cDNA-AFLP analysis are comparable to those found in Northern analysis. Furthermore, this paper reports the isolation and analysis of two tuberspecific transcript-derived fragments (TDFs) coding for the lipoxygenase enzyme, which are differentially induced around the time point of tuber formation. Analysis of the two Iox TDFs demonstrates that it is possible to dissect the expression modalities of individual transcripts, not independently detectable by Northern analysis. Finally, it is shown that using cDNA-AFLP, rapid and simple verification of band identity may be achieved. The results indicate that cDNA-AFLP is a broadly applicable technology for identifying developmentally regulated genes.

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Section: Discussionmentioning

confidence: 99%

Visualization of differential gene expression using a novel method of RNA fingerprinting based on AFLP: Analysis of gene expression during potato tuber development

Bachem¹,

Hoeven²,

et al. 1996

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“…Recently, the enzymatic specificity of this soybean LOX isoform (LOX4, synonymous to VLXA, vegetative lipoxygenase, isozyme A; gene family member Lox1:Gm:4) has been determined to preferentially produce (13S)-hydroxy linoleic acid (Fuller et al, 2001). The soybean LOX gene family consists of at least eight members (Siedow, 1991;Bunker et al, 1995). Since those isozymes that share the same substrate specificity are also structurally related (Fuller et al, 2001), one could speculate that the LOX4 probe would have detected transcripts of other 13-specific LOXs in our Northern blotting experiments.…”

Section: Discussionmentioning

confidence: 99%

The Role of Octadecanoids and Functional Mimics in Soybean Defense Responses

Fliegmann

Schüler

Boland

et al. 2003

Biological Chemistry

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Oxylipins of the jasmonate pathway and synthetic functional analogs have been analyzed for their elicitor-like activities in an assay based on the induced accumulation of glyceollins, the phytoalexins of soybean (Glycine max L.), in cell suspension cultures of this plant. Jasmonic acid (JA) and its methyl ester showed weak phytoalexin-inducing activity when compared to an early jasmonate biosynthetic precursor, 12-oxo-phytodienoic acid (OPDA), as well as to the bacterial phytotoxin coronatine and certain 6-substituted indanoyl-L-isoleucine methyl esters, which all were highly active. Interestingly, different octadecanoids and indanoyl conjugates induced the accumulation of transcripts of various defense-related genes to different degrees, indicating distinct induction competencies. Therefore, these signaling compounds and mimics were further analyzed for their effects on signal transduction elements, such as the transient enhancement of the cytosolic Ca 2 + concentration and MAP kinase activation, which are known to be initiated by a soybean pathogen-derived ␤-glucan elicitor. In contrast to the ␤-glucan elicitor, none of the other compounds tested triggered these early signaling elements. Moreover, endogenous levels of OPDA and JA in soybean cells were shown to be unaffected after treatment with ␤-glucans. Thus, OPDA and JA, which are functionally mimicked by coronatine and a variety of 6-substituted derivatives of indanoyl-L-isoleucine methyl ester, represent highly efficient signaling compounds of a lipid-based pathway not deployed in the ␤-glucan elicitor-initiated signal transduction.

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“…LOs have been isolated and characterized from numerous mammalian and plant sources and are believed to occur ubiquitously throughout these two phyla (1)(2)(3). In mammalian organisms, there are multiple LOs with differing regio-and stereospecificity against their substrate, arachidonic acid (AA).…”

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confidence: 99%

Spectroscopic Characterization of Soybean Lipoxygenase-1 Mutants: the Role of Second Coordination Sphere Residues in the Regulation of Enzyme Activity

et al. 2003

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Lipoxygenases are non-heme iron enzymes, which catalyze the stereo-and regiospecific hydroperoxidation of unsaturated fatty acids. Spectroscopic studies on soybean lipoxygenase have shown that the ferrous form of the enzyme is a mixture of five-and six-coordinate species (40 and 60%, respectively). Addition of substrate leads to a purely six-coordinate form. A series of mutations in the second coordination sphere (Q697E, Q697N, Q495A, and Q495E) were generated, and the structures of the mutants were solved by crystallography [Tomchick et al. (2001) Biochemistry 40, 7509-7517]. While this study clearly showed the contribution of H-bond interactions between the first and the second coordination spheres in catalysis, no correlation with the coordination environment of the Fe II was observed. A recent study using density-functional theory [Lehnert and Solomon (2002) J. Biol. Inorg. Chem. 8, 294-305] indicated that coordination flexibility, involving the Asn694 ligand, is regulated via H-bond interactions. In this paper, we investigate the solution structures of the second coordination sphere mutants using CD and MCD spectroscopy since these techniques are more sensitive indicators of the first coordination sphere ligation of Fe II systems. Our data demonstrate that the iron coordination environment directly relates to activity, with the mutations that have the ability to form a five-coordinate/six-coordinate mixture being more active. We propose that the H-bond between the weak Asn694 ligand and the Gln697 plays a key role in the modulation of the coordination flexibility of Asn694, and thus, is crucial for the regulation of enzyme reactivity.Lipoxygenases (LOs) 1 are mononuclear non-heme iron dioxygenases that catalyze the stereo-and regiospecific hydroperoxidations of cis,cis-1,4 polyunsaturated pentadienyl containing fatty acids. LOs have been isolated and characterized from numerous mammalian and plant sources and are believed to occur ubiquitously throughout these two phyla (1-3). In mammalian organisms, there are multiple LOs with differing regio-and stereospecificity against their substrate, arachidonic acid (AA). The products of these reactions are further metabolized by an array of enzymes leading to the formation of two major classes of cell effector molecules, leukotrienes and lipoxins, which are mediators in anaphylactic and inflammatory disorders (4, 5). Additionally, LO products are involved in a variety of metabolic functions, including organelle degradation (6), transcription regulation (7), and possibly tumor cell metastasis (8). For plant LOs, the main substrates are linoleic acid (LA) and linolenic acid, which are further metabolized to plant hormones, such as jasmonic acid. These hormones are involved in a variety of metabolic functions including plant growth and development, senescence, and cellular response to wounding and infections by pathogens (1). Soybeans have three LO isoforms (sLO-1, sLO-2, and sLO-3), which have homologous sequences and molecular weights of ∼96 kDa (9). This...

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Plant Lipoxygenase: Structure and Function

Cited by 695 publications

References 60 publications

Visualization of differential gene expression using a novel method of RNA fingerprinting based on AFLP: Analysis of gene expression during potato tuber development

Visualization of differential gene expression using a novel method of RNA fingerprinting based on AFLP: Analysis of gene expression during potato tuber development

The Role of Octadecanoids and Functional Mimics in Soybean Defense Responses

Spectroscopic Characterization of Soybean Lipoxygenase-1 Mutants: the Role of Second Coordination Sphere Residues in the Regulation of Enzyme Activity

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