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An Arabidopsis thaliana lipoxygenase gene can be induced by pathogens, abscisic acid, and methyl jasmonate. 总被引:33,自引:11,他引:22 下载免费PDF全文
M A Melan X Dong M E Endara K R Davis F M Ausubel T K Peterman 《Plant physiology》1993,101(2):441-450
We isolated and characterized a 2.8-kb, full-length, Arabidopsis thaliana cDNA clone encoding a lipoxygenase. DNA sequence analysis showed that the deduced amino acid sequence of the Arabidopsis protein is 72 to 78% similar to that of legume seed lipoxygenases. DNA blot analysis indicated that Arabidopsis contains a single gene, LOX1, with appreciable homology to the cDNA clone. RNA blot analysis showed that the LOX1 gene is expressed in Arabidopsis leaves, roots, inflorescences, and young seedlings. LOX1 expression levels were highest in roots and young seedlings. In mature plants, LOX1 mRNA levels increased upon treatment with the stress-related hormones abscisic acid and methyl jasmonate and remained high for at least 96 h. Expression of the LOX1 gene was examined following infiltration of leaves with virulent (Psm ES4326) and avirulent (Pst MM1065) strains of Pseudomonas syringae. LOX1 mRNA levels were induced approximately 6-fold by both virulent and avirulent strains; however, the response to avirulent strains was much more rapid. Infiltration of leaves with Pst MM1065 resulted in maximal induction within 12 h, whereas maximal induction by Psm ES4326 did not occur until 48 h. When a cloned avr gene, avrRpt2, was transferred to Psm ES4326, LOX1 mRNA accumulated in a pattern similar to that observed for the avirulent strain Pst MM1065. 相似文献
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A gene encoding a chloroplast-targeted lipoxygenase in tomato leaves is transiently induced by wounding, systemin, and methyl jasmonate. 总被引:25,自引:4,他引:21 下载免费PDF全文
We investigated the relationship between the expression of lipoxygenase (LOX) genes and the systemin-dependent wound response in tomato (Lycopersicon esculentum) leaves. A polymerase chain reaction-based approach was used to isolate two tomato Lox cDNAs, called TomLoxC and TomLoxD. Both TomLOXC and TomLOXD amino acid sequences possess an N-terminal extension of about 60 residues that were shown by in vitro uptake to function as transit peptides, targeting these proteins into the chloroplast. Within 30 to 50 min following wounding or systemin or methyl jasmonate treatments, the TomLoxD mRNA level increased and reached a maximum between 1 and 2 h. TomLoxC mRNA was not detectable in leaves and was not found following wounding, but it was found in ripening fruits, indicating that the two tomato Lox genes are regulated in different tissues by different processes. The results suggest that the TomLoxD gene is up-regulated in leaves in response to wounding and encodes a chloroplast LOX that may play a role as a component of the octadecanoid defense-signaling pathway. 相似文献
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Lipoxygenase gene expression is modulated in plants by water deficit, wounding, and methyl jasmonate 总被引:23,自引:0,他引:23
Summary Two classes of lipoxygenase (LOX) cDNAs, designated loxA and loxB, were isolated from soybean. A third lipoxygenase cDNA, loxP1, was isolated from pea. The deduced amino acid sequences of loxA and loxB show 61–74% identity with those of soybean seed LOXs. loxA and loxB mRNAs are abundant in roots and non-growing regions of seedling hypocotyls. Lower levels of these mRNAs are found in hypocotyl growing regions. Exposure of soybean seedlings to water deficit causes a rapid increase in loxA and loxB mRNAs in the elongating hypocotyl region. Similarly, loxP1 mRNA levels increase rapidly when pea plants are wilted. loxA and loxB mRNA levels also increase in wounded soybean leaves, and these mRNAs accumulate in soybean suspension cultures treated with 20 M methyl jasmonate. These results demonstrate that LOX gene expression is modulated in response to water deficit and wounding and suggest a role for lipoxygenase in plant responses to these stresses. 相似文献
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Expression of cucumber lipid-body lipoxygenase in transgenic tobacco: lipid-body lipoxygenase is correctly targeted to seed lipid bodies 总被引:2,自引:0,他引:2
A particular isoform of lipoxygenase (LOX, EC 1.13.11.12) localized on lipid bodies has been shown by earlier investigations
to play a role during seed germination in initiating the mobilization of triacylglycerols. On lipid bodies of germinating
cucumber (Cucumis sativus L.) seedlings, the modification of linoleoyl moieties by this LOX precedes the hydrolysis of the ester bonds. We analyzed
the expression and intracellular location of this particular LOX form in leaves and seeds of tobacco (Nicotiana tabacum L.) transformed with one construct coding for cucumber lipid-body LOX and one construct coding for cucumber LOX fused with
a hemagglutinin epitope. In both tissues, the amount of lipid-body LOX was clearly detectable. Biochemical analysis revealed
that in mature seeds the foreign LOX was targeted to lipid bodies, and the preferred location of the LOX on lipid bodies was
verified by immunofluorescence microscopy. Cells of the endosperm and of the embryo exhibited fluorescence based on the immunodecoration
of LOX protein whereas very weak fluorescent label was visible in seeds of untransformed control plants. Further cytochemical
analysis of transformed plants showed that the LOX protein accumulated in the cytoplasm when green leaves lacking lipid bodies
were analyzed. Increased LOX activity was shown in young leaves of transformed plants by an increase in the amounts of endogenous
(2E)-hexenal and jasmonic acid.
Received: 9 August 1999 / Accepted: 28 September 1999 相似文献
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Plants produce short‐chain aldehydes and hydroxy fatty acids, which are important industrial materials, through the lipoxygenase pathway. Based on the information that lipoxygenase activity is up‐regulated in tobacco leaves upon infection with tobacco mosaic virus (TMV), we introduced a melon hydroperoxide lyase (CmHPL) gene, a tomato peroxygenase (SlPXG) gene and a potato epoxide hydrolase (StEH) into tobacco leaves using a TMV‐based viral vector system to afford aldehyde and hydroxy fatty acid production. Ten days after infiltration, tobacco leaves infiltrated with CmHPL displayed high enzyme activities of 9‐LOX and 9‐HPL, which could efficiently transform linoleic acid into C9 aldehydes. Protein extracts prepared from 1 g of CmHPL‐infiltrated tobacco leaves (fresh weight) in combination with protein extracts prepared from 1 g of control vector‐infiltrated tobacco leaves (as an additional 9‐LOX source) produced 758 ± 75 μg total C9 aldehydes in 30 min. The yield of C9 aldehydes from linoleic acid was 60%. Besides, leaves infiltrated with SlPXG and StEH showed considerable enzyme activities of 9‐LOX/PXG and 9‐LOX/EH, respectively, enabling the production of 9,12,13‐trihydroxy‐10(E)‐octadecenoic acid from linoleic acid. Protein extracts prepared from 1 g of SlPXG‐infiltrated tobacco leaves (fresh weight) in combination with protein extracts prepared from 1 g of StEH‐infiltrated tobacco leaves produced 1738 ± 27 μg total 9,12,13‐trihydroxy‐10(E)‐octadecenoic acid isomers in 30 min. The yield of trihydroxyoctadecenoic acids from linoleic acid was 58%. C9 aldehydes and trihydroxy fatty acids could likely be produced on a larger scale using this expression system with many advantages including easy handling, time‐saving and low production cost. 相似文献
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Wenlian Deng W. Scott Grayburn Thomas R. Hamilton-Kemp Glenn B. Collins David F. Hildebrand 《Planta》1992,187(2):203-208
To assess the role of lipoxygenase (LOX; EC 1.13.11.12) in plants, we increased the expression of LOX in the tissues of Nicotiana tabacum L. cv. KY 14 by over-expression of the LOX2 gene from the soybean (Glycine max (L.) Merrill) embryo. The LOX2 cDNA was manipulated by replacing its 5-untranslated sequence with the translational enhancer of the alfalfa mosaic virus (AMV), and subcloned into a plant expression vector, 3 to a duplicated cauliflower mosaic virus 35S promoter. The AMV-LOX2 construct was transferred into tobacco using Agrobacterium tumefaciens strain A281. The LOX2 was expressed in transgenic tobacco calli, leaves of transgenic plants, and their seed progeny at levels up to 0.1–0.2% of the total extracted protein. The introduced LOX2 affected fatty-acid oxidative metabolism as evidenced by a 50–529% increase in C6-aldehyde production. The impact on C6-aldehyde formation was greater than the effect on production of fatty-acid hydroperoxides. This is consistent with other studies indicating the greater propensity of soybean embryo LOX2 in generating C6-aldehydes than that of other well-characterized LOX isozymes.Abbreviations AMV
alfalfa mosaic virus
- CaMV
cauliflower mosaic virus
- IEF
isoelectric focusing
- kDa
kilodalton
- LOX
lipoxygenase
- SDS-PAGE
sodium dodecyl sulfate-polyacrylamide gel electrophoresis
We thank Bernard Axelrod (Purdue University) for supplying the lipoxygenase 2 cDNA, and Arthur G. Hunt (University of Kentucky) for supplying the pKYLX712 and pBS/AMV. The advice of Arthur G. Hunt, Chris L. Schardl, Sadik Tuzun and Dwight Tomes is greatly appreciated, as is the technical assistance of Udaya Chand and Robert Versluys. 相似文献
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Isolation of lipoxygenase cDNA clones from pea nodule mRNA 总被引:4,自引:0,他引:4
Wisniewski Jean-Pierre Gardner Christopher D. Brewin Nicholas J. 《Plant molecular biology》1999,39(4):775-783
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Summary Lipoxygenases (EC 1.13.11.12) catalyse the oxygenation of polyunsaturated fatty acids such as linoleic and arachidonic acid into reactive cis/trans hydroperoxidiene intermediates, which then serve as substrates for other enzymes leading to the production of a variety of secondary metabolites. In order to explore the characteristics of the individual lipoxygenase isoenzymes in more detail larger amounts of the pure enzymes are needed and their production in a heterologous host is therefore desirable. Full-length cDNAs encoding pea-seed lipoxygenase isoenzymes 2 and 3 were expressed in Saccharomyces cerevisiae with the aid of yeast-Escherichia coli shuttle vectors. Expression of the cDNA for lipoxygenase 2 under the control of the constitutive phosphoglycerate kinase (PGK) gene promoter yielded significant amounts of active enzyme inside the cell, both with yeast transformants carrying the cDNA gene on high-copy-number plasmids or integrated in chromosome V. Addition of the yeast invertase signal sequence in front of the pea lipoxygenase 3 yielded secreted active pea-seed lipoxygenase in the medium, but large amounts of inactive lipoxygenase 3 remained inside the yeast cell. Expression of the LOX3 cDNA can be achieved either constitutively with the PGK promoter or inducibly with the GAL1 promoter.
Correspondence to: B. Knust 相似文献
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Possible participation of the peroxidation system in the cultivar-race specificity was studied for the oat-crown rust system. The levels of lipid peroxidation and total lipoxygenase (LOX) activity were extensively increased in leaves of cv. Shokan l responding with resistance to race 226. One anionic and one cationic LOX isozyme was detected in the extract of Shokan 1 leaves inoculated with race 226. In addition, three anionic and one cationic isozymes were consistently found in the extract of uninoculated and compatible race 203-inoculated leaves. The blockage experiments with race 226-inoculated leaves using RNA and protein synthesis inhibitors indicated that the two LOX isozymes characteristic of the incompatible combination are de novo synthesized and their activity is causally linked to the resistance expression. Production of the two isozymes was also demonstrated in the five resistant Pc oat lines, but not in the two susceptible Pc lines. 相似文献
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Soybean seed lipoxygenase genes: molecular characterization and development of molecular marker assays 总被引:1,自引:0,他引:1
Julian M. Lenis Jason D. Gillman Jeong Dong Lee J. Grover Shannon Kristin D. Bilyeu 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2010,120(6):1139-1149
Soybean seeds contain three lipoxygenase (Lox) enzymes that are controlled by separate genes, Lox1, Lox2 and Lox3. Lipoxygenases play a role in the development of unpleasant flavors in foods containing soybean by oxidation of polyunsaturated
fatty acids. Null alleles for all three enzymes have been identified, lox1, lox2 and lox3, and are known to be inherited as simple recessive alleles. Previous studies determined that a missense mutation rendered
Lox2 inactive; however, the genetic cause of either lox1 or lox3 mutation was not known. The objectives of this study were the molecular characterization of both lox1 and lox3 mutant alleles and the development of molecular markers to accelerate breeding for Lox-free soybean varieties. We identified
two independent mutant alleles as the genetic causes of the lack of Lox1 in seeds of two lox1 mutant soybean lines. Similarly, a mutant allele that truncates Lox3 in a lox3 mutant soybean line was identified. Molecular markers were designed and confirmed to distinguish mutant, wild type, and heterozygous
individuals for Lox1, Lox2 and Lox3 genes. Genotype and Lox phenotype analysis showed a perfect association between the inheritance of homozygous lox mutant alleles and the lack of Lox activity. Molecular characterization of a seed-lipoxygenase-free soybean line led to the
discovery that an induced recombination event within the Lox1 gene was responsible for breaking the tight linkage in repulsion phase between mutant alleles at the Lox1 and Lox2 loci. The molecular resources developed in this work should accelerate the inclusion of the lipoxygenase-free trait in soybean
varieties. 相似文献