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Biological roles and biochemistry of lipoxygenase pathway
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... Nonanoic acid and hexanal were detected in high concentrations of the essential oils extracted using CP both orange and tangor. Hexanal, which is formed from linoleic acid via the lipoxygenase pathway (Gardner, 1995), is an important volatile compound that contributes to a green odor note (Gardner, 1995). It has been utilized in food and fragrance products to give fresh organoleptic note (Rouhi, 1999). ...
... Nonanoic acid and hexanal were detected in high concentrations of the essential oils extracted using CP both orange and tangor. Hexanal, which is formed from linoleic acid via the lipoxygenase pathway (Gardner, 1995), is an important volatile compound that contributes to a green odor note (Gardner, 1995). It has been utilized in food and fragrance products to give fresh organoleptic note (Rouhi, 1999). ...
Citrus fruits are largely consumed due to their unique and pleasant aromas. Citrus hybrids have been developed to enhance their flavors and bioactivities. Citrus aroma depends on the composition of the volatile compounds in citrus essential oils (CEOs), which are mostly located in the peels. During the extraction of CEOs, a specific series of chemical reactions occurred depending on the extraction methods (CP, cold pressing; HD, hydrodistillation), leading to variations in the composition of volatile compounds. In this study, the orange and the tangor which is a hybrid between C. reticulata × C. sinensis were investigated to compare the changes in volatile compounds based on the extraction methods. Results showed that the CP‐specific volatile compounds were sesquiterpenes, oxygenated monoterpenes, and fatty acid derivatives, while the HD‐specific volatile compounds were terpinyl cation derivatives, limonene, and 4‐vinylguaiacol. On the other hand, the contents of some volatile compounds ((E)‐ocimene, α‐terpinene, and α‐terpinolene) were affected by the Citrus species rather than by the extraction methods. In particular, during HD, terpinene‐4‐ol and 4‐vinylguiacol, known as off‐flavor compounds in citrus juice, were formed more abundantly in the orange than in the tangor. In conclusion, these results provide comprehensive data on essential oils, especially those derived from oranges and tangors, for selecting the appropriate extraction method for obtaining a higher yield and quality of citrus flavor.
... Lipooxygenase are enzymes which catalyze oxygenation of polyunsaturated fatty acids with one or several pentadiene units to hydroperoxy fatty acids which possess a range of biological functions such as diverse signal molecules, oxidants and modi ers of membrane structures [30][31]. Lipooxygenase are identi ed as an enzyme of early response in host pathogen interaction [31]. ...
... Lipooxygenase are enzymes which catalyze oxygenation of polyunsaturated fatty acids with one or several pentadiene units to hydroperoxy fatty acids which possess a range of biological functions such as diverse signal molecules, oxidants and modi ers of membrane structures [30][31]. Lipooxygenase are identi ed as an enzyme of early response in host pathogen interaction [31]. Con ict of interest: The authors declare that they have no con ict of interest. ...
Background Fusarium fujikuroi causing bakanae is one of the most significant pathogen of rice and much responsible for yield losses thereby emerging as a major risk to food security.
Methods In the present study transcriptomic analysis was conducted between two contrasting resistant (C101A51) and susceptible (Rasi) genotypes of rice with the combinations of C101A51 control (CC) vs C101A51 inoculated (CI); Rasi control (RC) vs Rasi inoculated (RI) and C101A51 inoculated (CI) vs Rasi inoculated (RI).
Results In CC vs CI commonly expressed genes were 12,764. Out of them 567 (4%) were significantly upregulated and 1399 (9%) genes were down regulated. For the RC vs RI 14, 333 (79%) genes were commonly expressed. For CI vs RI 13,662 (72%) genes commonly expressed. Cysteine proteinase inhibitor 10, disease resistance protein TAO1-like, oleosin 16 kDa-like, pathogenesis-related protein (PR1), (PR4), BTB/POZ and MATH domain-containing protein 5-like, alpha-amylase isozyme 3D-like (LOC4345814), were upregulated in resistant genotype C101A51. Whereas, GDSL esterase/lipase At5g33370, serine glyoxylate aminotransferase, CASP-like protein 2C1, WAT1-related protein At4g08290, Cytoplasmic linker associated proteins, xyloglucan endotransglucosylase/hydrolase protein and β-D xylosidase 7 were upregulated in susceptible genotype Rasi. Gene ontology analysis showed functions related to defence response (GO:0006952), regulation of plant hypersensitive type response (GO:0010363), Potassium ion transmembrane activity (GO:0015079), chloroplast (GO:0009507), response to wounding (GO:0009611), xylan biosynthetic process (GO:0045492) were upregulated in resistant genotype C101A51 under inoculated conditions.
Conclusions Real time PCR based validation of the selected DEGs showed that the qRT-PCR was consistent with the RNA-Seq results. This is the first transcriptomic study against bakanae disease of rice in Indian genotypes and will be helpful for the development of bakanae management strategies.
... Lipooxygenase are enzymes which catalyze oxygenation of polyunsaturated fatty acids with one or several pentadiene units to hydroperoxy fatty acids which possess a range of biological functions such as diverse signal molecules, oxidants and modifiers of membrane structures [34,35]. Lipooxygenase are identified as an enzyme of early response in host pathogen interaction [35]. ...
... Lipooxygenase are enzymes which catalyze oxygenation of polyunsaturated fatty acids with one or several pentadiene units to hydroperoxy fatty acids which possess a range of biological functions such as diverse signal molecules, oxidants and modifiers of membrane structures [34,35]. Lipooxygenase are identified as an enzyme of early response in host pathogen interaction [35]. For instance lipooxygenase expression is induced in rice cultivars upon infection by blast fungi, Magnaporthe grisea. ...
Background
Fusarium fujikuroi causing bakanae is one of the most significant pathogens of rice and much responsible for yield losses thereby emerging as a major risk to food security.
Methods
In the present study transcriptomic analysis was conducted between two contrasting resistant (C101A51) and susceptible (Rasi) genotypes of rice with the combinations of C101A51 control (CC) vs. C101A51 inoculated (CI); Rasi control (RC) vs. Rasi inoculated (RI) and C101A51 inoculated (CI) vs. Rasi inoculated (RI).
Results
In CC vs. CI commonly expressed genes were 12,764. Out of them 567 (4%) were significantly upregulated and 1399 (9%) genes were downregulated. For the RC vs. RI 14, 333 (79%) genes were commonly expressed. For CI vs. RI 13,662 (72%) genes were commonly expressed. Genes related to cysteine proteinase inhibitor 10, disease resistance protein TAO1-like, oleosin 16 kDa-like, pathogenesis-related protein (PR1), (PR4), BTB/POZ and MATH domain-containing protein 5-like, alpha-amylase isozyme were upregulated in resistant genotype C101A51. Whereas, genes related to GDSL esterase/lipase, serine glyoxylate aminotransferase, CASP-like protein 2C1, WAT1-related protein, Cytoplasmic linker associated proteins, xyloglucan endotransglucosylase/hydrolase protein and β-D xylosidase 7 were upregulated in susceptible genotype Rasi. Gene ontology analysis showed functions related to defence response (GO:0006952), regulation of plant hypersensitive type response (GO:0010363), Potassium ion transmembrane activity (GO:0015079), chloroplast (GO:0009507), response to wounding (GO:0009611), xylan biosynthetic process (GO:0045492) were upregulated in resistant genotype C101A51 under inoculated conditions.
Conclusion
Real time PCR based validation of the selected DEGs showed that the qRT-PCR was consistent with the RNA-Seq results. This is the first transcriptomic study against bakanae disease of rice in Indian genotypes. Further, functional studies on identified genes and their utilization through different methodology will be helpful for the development of bakanae disease management strategies.
... Soy lipoxygenase exhibits structural homology to human lipoxygenase. However, in plants, lipoxygenase metabolizes linoleic and linolenic acid, and in animals, lipoxygenase metabolizes arachidonic acid (Gardner, 1995). All lipoxygenases contain a single nonheme iron per molecule of enzyme. ...
... Soy lipoxygenase exhibits structural homology to human lipoxygenase. However, in plants, lipoxygenase metabolizes linoleic and linolenic acid, and in animals, lipoxygenase metabolizes arachidonic acid (Gardner, 1995). All lipoxygenases contain a single nonheme iron per molecule of enzyme. ...
Tribulus terrestris fruit has been used as a traditional and popular medicine for the prevention and treatment of several diseases, including sexual dysfunction, atherosclerosis and hypertension. The aim of this study was to evaluate the antioxidant, lipoxygenase and α-glucosidase inhibitory activities of an ethanol extract from Brazilian T. terrestris and its fractions sequentially partitioned into n-hexane, dichloromethane, ethyl acetate and n-butanol. The antioxidant capacities were determined by DPPH and ABTS scavenging free radicals, chelating metal ions, reducing power and total antioxidant activity by using phosphomolybdenum. High-performance liquid chromatography with diode array detection (HPLC-DAD) fingerprint analysis and quantitation of total phenolics were performed on the samples. The dichloromethane fraction showed the most complex HPLC-DAD chemical profile. The ethyl acetate and butanol fractions revealed the best phenolic compound and flavonoid recovery from T. terrestris. Concerning antioxidant activity, the ethyl acetate fraction presented better capacity for scavenging DPPH, ABTS and hydroxyl radicals, reductive power, total antioxidant capacity (TAC) and α-glucosidase inhibitory activity than the other fractions. These results correlated closely with the levels of phenolic compounds and flavonoids. The hexane fraction showed the best metal chelating power and lipoxygenase inhibitory activity. The anti-diabetic and anti-inflammatory potential of Brazilian Tribulus terrestris depend on the method of preparation.
... These fatty acids are then subjected to oxidation by lipoxygenase or cyclooxygenase and the formation of endoperoxides or hydroperoxides, respectively takes place. These two compounds undergo a number of reactions to form long-chain fatty acids (Gardner 1995). ...
Food products undergo enzymatic and non-enzymatic browning due to reactions among amino acids and proteins with simple/complex carbohydrate, oxidized phenolic clusters, and oxidized fats/lipids leading to deterioration during processing and storage. Enzymatic browning occurs in fruits and vegetables when exposed to atmosphere during physical abrasions. Enzymes viz., polyphenol oxidase (PPO) and peroxidase (POD) are mainly responsible for this type of browning. PPO catalyzes the oxidation of the functional –OH group linked to the carbon atom of the benzene ring of monohydroxy phenols and dehydrogenation of o-dihydroxy phenols to o-quinones. The oxidation of phenolic compounds to quinones and the formation of melanin give dusky color to the foods. The POD uses H2O2 as a catalyst for the oxidation of phenolic compounds. The POD is allied to undesirable changes in flavor, texture, color, and the nutritional efficacy of foods. The level of PPO and POD varies in fruit and vegetable, and its content changes with maturity and senescence dependent upon the ratio of bounded and soluble enzymes. Non-enzymatic browning consists of a varied number of reactions such as Maillard reaction, chemical oxidation of phenols, maderization and caramelization. Possible methodologies to inhibit these browning reactions during food processing are described in this chapter.
... AFB 1 biosynthesis is affected by lipid oxidation, and interactions with linolenic and linoleic acids and their metabolites (De Luca et al., 1995). Linolenic and linoleic acids can be oxidized by plant-stress response lipoxygenase (LOX) (Gardner, 1995). Lipoxygenase isozymes catalyse the formation of hydroperoxy fatty acids which can be further metabolised by other plant enzymes to give a variety of jasmonic acid derivatives including methyl jasmonate (MeJA). ...
The evaluation of exposure to aflatoxins (AF) by measurement of the level of contamination in food is hampered due to the heterogeneous distribution of AF in food. Therefore, an alternative is to estimate the exposure using specific biological markers (biomarkers) based on an understanding of the metabolism of the albumin compound.(AF-alb) For in AF, the these blood. include This study aflatoxin-N7-guanine assessed the level in of the exposure urine, or to AFBAF in
... Plant's linoleic acid and 9-and 13-hydroperoxy fatty acids (9S-and 13S-HPODE oxylipin products) have a substantial effect on the differentiation processes of Aspergillus spp. Both 9S-and 13S-HPODE alter secondary metabolism in A. parasiticus and A. nidulans (Gardner, 1995;Burow et al., 1997). They also increase the production of the conidiospores in A. nidulans and A. flavus, and, in A. nidulans, elevate cAMP levels (Calvo et al., 1999;Affeldt et al., 2012). ...
Species of the highly diverse fungal genus Aspergillus are well-known agricultural pests and, most importantly, producers of various mycotoxins threatening food safety worldwide. Mycotoxins are studied predominantly from the perspectives of human and livestock health. Meanwhile, their roles are far less known in nature. However, to understand the factors behind mycotoxin production, the roles of the toxins of the Aspergilli must be understood from a complex ecological perspective, taking mold–plant, mold–microbe, and mold–animal interactions into account.
The Aspergilli may switch between saprophytic and pathogenic lifestyles, and the production of secondary metabolites, such as mycotoxins, may vary according to these fungal ways of life. Recent studies highlighted the complex ecological network of soil microbiotas determining the niches that Aspergilli can fill in. Interactions with the soil microbiota and soil macro-organisms determine the role of secondary metabolite production to a great extent. While, upon infection of plants, metabolic communication including fungal secondary metabolites like aflatoxins, gliotoxin, patulin, cyclopiazonic acid, ochratoxin, influences the fate of both the invader and the host.
In this review, the role of mycotoxin producing Aspergillus species and their interactions in the ecosystem are discussed. We intend to highlight the complexity of the roles of the main toxic secondary metabolites as well as their fate in natural environments and agriculture, a field that still has important knowledge gaps.
... However, not all of these processes take place when a fruit is freshly-cut. For example, in the case of the apple, as in most of similar type of fruits, the main enzymatic system activated to produce aromatic compounds is lipoxygenase (LOX) pathway (Gardner 1995;Sanz et al. 1997). LOX is dioxygenase that catalyses the oxygenation of polyunsaturated fatty acids containing cis-penta-1,4-diene fraction, and the product is conjugated diene (cis,trans)-hydroperoxide (Espino-Díaz et al. 2016;Hamberg and Samuelsson 1967;Holman et al. 1969). ...
The review presents typical pathways of artefacts generation from the plant and honey phytochemicals: (a) cutting of the fresh plant material (with or without characteristic aroma release); (b) drying process of the plant material; (c) distillation or extraction; (d) thermal processing; (e) storage; (f) gas chromatography and mass spectrometry analysis. Major reactions of artefacts formation were presented (oxidation, hydrolysis, H2O addition, degradation, rearrangement, others) in order to point out general mechanisms of the artefacts formation that could occur in any sample containing particular phytochemical molecular structures. Degradation of phytochemicals and formation of the artefacts depends on several chemical and external factors (such as temperature, water, light, accessibility to atmospheric oxygen, chemical composition, compound structures, or presence of impurities). Most common examples of volatile artefacts generation were presented. Detail analysis, based on different preparative methods, should be performed as a part of the analytical toolbox to obtain more complete understanding on the artefacts formation.
Controlling the enzyme activity shows potential for significant contributions to the pre−/postharvest food industry. In this chapter, the physicochemical factors of plasma mainly in terms of reactive species, taking into account electric fields, and the effects of each element on enzyme activity are discussed. The mechanism will be discussed from multiple angles, centring on conformational changes in proteins. Appropriate plasma control based on quantitative studies on the enzymatic activity and protein conformation of each plasma-induced factor has the potential to greatly contribute to innovative agricultural applications.
The metabolization of trans-2-hexenal - one of the main components of plant wound gases with antibiotic activity - was investigated for 5 different isolates of Botrytis cinerea PERS. The transformation products as well as the kinetics of their formation were analyzed.
Isolates exclusively mycelium forming (Bc 1 and Bc 13) transformed tr-2-hexenal into tr-2- hexenol, while sporulating isolates (Bc 3, Bc 9 and Bc 10) converted tr-2-hexenal to hexanol-1.
Basically the metabolization of tr-2-hexenal proceeded in the same way via the aqueous phase as in the gas phase.
The transformation products tr-2-hexenol and hexanol-1 showed significantly lower toxicity against the tested B. cinerea isolates than tr-2-hexenal. In each isolate the end product of tr-2- hexenal conversion had the weakest inhibitory activity. The transformation reactions thus represent detoxification mechanisms for these fungi.
Numerous studies have demonstrated induction of proteins in plant tissues by wounding and infestations by various pests and pathogens. Lipoxygenase (LOX) is among the proteins that has been found to be induced by pathogens, but detailed information on the induction of LOX has not been reported. We have found a large (up to 10-fold) increase in LOX activity upon wounding of soybean (Glycine max L. Merr.) leaves and variable increases due to feeding of the twospotted spider mite. This induction in LOX activity was reflected in increases in amounts of both LOX protein and transcripts suggesting that the induction was at the transcriptional level. LOX activity was also found to be increased in unwounded leaves from plants with wounded leaves lower on the stem indicating that translocatable factors can cause remote induction of LOX activity.
In cucumber cotyledons, both C6- and C9- aldehyde were formed via hydroperoxide (HPO) lyase activity. Because it has not been elucidated whether these activities are attributed to one enzyme which can cleave both 13-and 9-HPO or to two or more enzymes each of which specifically cleaves 13-or 9-HPO , an attempt to separate HPO lyase activity was done. Ion exchange chromatography separated this activity into two fractions, one of which specifically cleaved 13-hydroperoxylinoleic acid and the other specifically cleaved the 9-isomer. 13-HPO-specific activity was most active at pH 8.0 and 9-HPO-specific one was at pH 6.5. SH -reagents inhibited both the lyases but to different extents.
When taro tubers (Colocasia antiquorum Schott) were inoculated by a taro strain (compatible or pathogenic) or a sweet potato strain (incompatible or non-pathogenic) of Ceratocystis fimbriata, lipid peroxidation, which was measured by the thiobarubituric acid reaction, took place to a similar magnitude and with a similar course in both kinds of tubers. Throughout the incubation period, no generation of superoxide anions (O2⁻) due to inoculation by either strain was detected in the tubers. The activities of phospholipase A2 and lipoxygenase changed in a manner accounting for the production of lipid peroxides observed in taro tubers inoculated by both strains. The sweet potato and taro strains had similar sensitivity to the toxicity of peroxides of linolenic acid and lipid peroxides from inoculated taro tubers. These results suggested that lipid peroxide produced by the host plant was involved in the early host-parasite interaction in this system. © 1990, Japan Society for Bioscience, Biotechnology, and Agrochemistry. All rights reserved.
When taro tubers (Colocasia antiquorum Schott) were inoculated by a taro strain (compatible or pathogenic) or a sweet potato strain (incompatible or non-pathogenic) of Ceratocystis fimbriata, lipid peroxidation, which was measured by the thiobarubituric acid reaction, took place to a similar magnitude and with a similar course in both kinds of tubers. Throughout the incubation period, no generation of superoxide anions (02) due to inoculation by either strain was detected in the tubers. The activities of phospholipase A2 and lipoxygenase changed in a manner accounting for the production of lipid peroxides observed in taro tubers inoculated by both strains. The sweet potato and taro strains had similar sensitivity to the toxicity of peroxides of linolenic acid and lipid peroxides from inoculated taro tubers. These results suggested that lipid peroxide produced by the host plant was involved in the early host-parasite interaction in this system. © 1990 by the Japan Society for Bioscience, Biotechnology, and Agrochemistry. All rights reserved.
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.
13-Hydroperoxides (ROOH) and 13-hydroxides (ROH) of both linoleic and linolenic acids rapidly increased after inoculating press-injured spots of rice leaves with Pyricularia oryzae. The highest concentrations of ROOH and ROH were reached within 24 hr after inoculating with P. oryzae. On the contrary, the production of momilactone A, a terpenoid rice phytoalexin, began 24 hr after inoculating with P. oryzae, while the momilactone A level peaked at 96 hr after the inoculation. The 13-hydroperoxides and 13-hydroxides of linoleic and linolenic acids can thus induce phytoalexins production. Quinacrine, an inhibitor of phospholipase A2, and the lipoxygenase inhibitor, nor-dihydroguaiaretic acid (NDGA), inhibited not only the production of ROOH and ROH, but also any phytoalexin accumulation following invasion by P. oryzae. Chlorogenic acid, by inhibiting the peroxidase of rice plants, inhibited the production of ROH and the rice phytoalexins accompanying an accumulation of ROOH. These data suggest that the oxyge...