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1.
The roots of date palm contain four cell wall‐bound phenolic acids identified as p‐hydroxybenzoic, p‐coumaric, ferulic and sinapic acids. The ferulic acid represents the major phenolic compound since it constitutes 48.2–55.8% of cell wall‐bound phenolic acids. All these phenolic acids were present in the resistant cultivar (BSTN) and the susceptible cultivar (JHL). However, the pre‐infection contents of p‐coumaric, ferulic and sinapic acids were greater in the resistant cultivar than in the susceptible one. For the contents of p‐hydroxybenzoic acid, there was no significant difference between the resistant cultivar and the susceptible cultivar. Similarly, the pre‐infection contents of lignin were approximately equal for both cultivars. Inoculation of the date palm roots by Fusarium oxysporum f. sp. albedinis induced important modifications to the contents of the cell wall‐bound phenolic compounds and lignin, which made it possible to distinguish between resistant and susceptible cultivars. The post‐infection contents of cell wall‐bound phenolic compounds underwent a rapid and intense increase with a maximum accumulation on the tenth day for p‐hydroxybenzoic acid (1.54 μmol/g), p‐coumaric acid (2.77 μmol/g) and ferulic acid (2.64 μmol/g) and on the fifteenth day for sinapic acid (1.85 μmol/g). The maximum contents accumulated in the resistant cultivar were greater than those in the susceptible cultivar, namely, 11 times for p‐hydroxybenzoic acid, 2.6 times for p‐coumaric acid, 1.8 times for ferulic acid and 12.3 times for sinapic acid. In the susceptible cultivar, p‐coumaric acid and ferulic acid contents also increased after inoculation although they did not reach the pre‐infection contents of the resistant cultivar. The contents of p‐hydroxybenzoic acid in the susceptible cultivar roots did not present post‐infection modification and those of sinapic acid decreased instead. The lignin contents increased in both cultivars with a maximum accumulation on the fifteenth day. However, the maximum contents accumulated in the resistant cultivar roots were 1.5 times greater than those of the susceptible cultivar. These results showed clear differences between the resistant BSTN and the susceptible JHL cultivars. The implication of cell wall‐bound phenolic compounds and lignin in the resistance of date palm to F. oxysporum f. sp. albedinis appears to be dependent on the speed and intensity of their accumulation with greater contents in the first stage of infection.  相似文献   

2.
Fusarium oxysporum f. sp. albedinis, the bayoud disease agent of date palm, grows on a mineral medium containing the cell walls of date palm roots as a sole carbohydrate source. The growth and development of pathogen under these conditions was related to the production of extracellular cell wall-degrading enzymes (CWDE): cellulases, polygalacturonases, polygalacturonate transeliminases, and pectinmethylesterases. The mycelial growth and the sporulation of pathogen were higher in the presence of cell walls of susceptible cultivars (BFG, JHL, BSK) than in the presence of those of resistant cultivars (IKL, SLY, BSTN). After 8 d of fungal culture, the activity of CWDE was equal whatever is the origin of the cell walls (resistant or susceptible cultivars). After 16 d of culture, the activity of these CWDE was higher when the parasite was cultivated on the cell walls of the susceptible cultivars than on those of the resistant cultivars. A positive correlation was observed between CWDE activities and the growth and the sporulation of F. oxysporum after 16 d of culture. These results clearly show a relation between the susceptibility/resistance of the cell walls of the roots of the date palm to the parasitic CWDE and the susceptibility/resistance of the cultivars.  相似文献   

3.
The study presents the comparative analyses of endogenous contents of auxin (IAA), cytokinins (CKs), polyamines (PAs), and phenolic acids (PhAs) in apical and basal parts of elm multiplicated shoots with regard to the organogenic potential. The shoot-forming capacity was higher in the apical part than in the basal part. However, the timing of root formation was in the apical type of explant significantly delayed (compared with the organogenic potential of basal part). Significantly higher contents of free bases, ribosides and ribotides of isopentenyl adenine, zeatin and dihydrozeatin that were found in the apical segments, might be considered as the most important factor affecting in vitro shoot formation. The content of endogenous free IAA was approximately three times higher in the basal shoot parts than in the apical parts. The amounts of putrescine and spermidine were higher in the apical part which generally contains less differentiated tissues than the basal part of shoot. The predominant PhA in both types of explants was caffeic acid, and concentrations of other PhAs decreased in the following order: p-coumaric, ferulic, sinapic, vanillic, chlorogenic, p-hydroxybenzoic and gallic acids. The contents of all determined PhAs in their free forms and higher contents of glycoside-bound p-coumaric, ferulic and sinapic acids, precursors for lignin biosynthesis, were found in the basal parts.  相似文献   

4.
Fungal laccase oxidized derivatives of hydroxycinnamic acid. The rates decreased in the order sinapic acid > ferulic acid ≥p-coumaric acid. The laccase oxidized sinapyl alcohol faster than coniferyl alcohol. The rates of oxidation of the hydroxycinnamic acid derivatives by an isoenzyme of peroxidase from horseradish decreased in the order p-coumaric acid > ferulic acid ≥ sinapic acid. The peroxidase oxidized coniferyl alcohol much faster than sinapyl alcohol. The laccase and the peroxidase predominantly oxidized (a) ferulic acid in a reaction mixture that contained p-coumaric acid and ferulic acid, (b) sinapic acid in a mixture of p-coumaric acid plus sinapic acid, and (c) sinapic acid in a mixture of ferulic acid plus sinapic acid. In a reaction mixture that contained both coniferyl and sinapyl alcohols, both fungal laccase and horseradish peroxidase predominantly oxidized sinapyl alcohol. From these results, it is concluded (1) that the p-hydroxyphenyl radical can oxidize guaiacyl and syringyl groups and produce their radicals and (2) that the guaiacyl radical can oxidize the syringyl group under formation of its radical; and that (3) in both cases the reverse reactions are very slow.  相似文献   

5.
1. Artificial lignins have been produced on potato parenchyma. 2. The methoxyl-free lignin and 4-hydroxy-3-methoxy (guaiacyl) lignins could be estimated by the sulphuric acid method but the 4-hydroxy-3,5-dimethoxy (syringyl) lignins could not. 3. Permanganate oxidation of isolated p-coumaric lignin gave 4-hydroxybenzoic acid, 4-hydroxyisophthalic acid and small amounts of hydroxytrimesic acid and 4-hydroxyphthalic acid. Ferulic lignin gave vanillic acid and 5-carboxyvanillic acid and also small amounts of 4-hydroxybenzoic acid and dehydrodivanillic acid. The sinapic lignin gave traces of syringic acid and of 4-hydroxybenzoic acid. 4. The p-coumaric lignin is a highly condensed polymer. The ferulic lignin is partly uncondensed and partly condensed through the 5-position like gymnosperm lignin. The sinapic lignin shows no evidence of condensation and is probably an ether-linked polymer.  相似文献   

6.
Treatment of vegetative parts of potato plants two weeks before the harvest with 0.2% 2-chloroethylphosphonic acid (CEPA) delayed the sprouting of tubers and increased the resistance of tubers to infections caused byPhytophthora infestans, Erwinia carotovora andFusarium spp. during the storage period. Levels of free, soluble ester- and glycoside-bound phenolic acids and cell wall-bound phenolics were determined in cortical parenchyma of tubers (periderm). The enhancement of phenolic acids in tubers from treated plants was caused primarily by the increase in the contents of free vanillic, caffeic andp-hydroxybenzoic acids and cell wall-bound ferulic, vanillic andp-coumaric acids.  相似文献   

7.
Major cell wall-bound phenolic compounds were detected and identified in roots of tomato at different stages of growth. Alkaline hydrolysis of the cell wall material of the root tissues yielded ferulic acid as the major bulk of the phenolic compounds. Other phenolic compounds identified were 4-hydroxybenzoic acid, vanillic acid, 4-hydroxybenzaldehyde, vanillin and 4-coumaric acid. All the six phenolic acids were higher in very early stage of plant growth. Ferulic acid, 4-hydroxybenzoic acid and 4-coumaric acid exhibited a decreasing trend up to 60 days and then the content of these phenolic acids increased somewhat steadily towards the later stage of growth. Total phenolics, phenylalanine ammonia-lyase (PAL) activity and peroxidase (POD) activity were in tandem match with the occurrence pattern of the phenolic acids. Ferulic acid showed highest antifungal activity against tomato wilt pathogen Fusarium oxysporum f. sp. lycopersici. The results of this study may be interpreted to seek an explanation for high susceptibility of tomato plants at flowering stage to Fusarium wilt. It may also be concluded that greater amounts of ferulic acid in combination with other phenolics and higher level of PAL and POD activities after 60 days of growth may have a role in imparting resistance against Fusarium wilt at a late stage of plant growth.  相似文献   

8.
Cinnamic acid and its hydroxylated derivatives (p-coumaric, caffeic, ferulic and sinapic acids) are known allelochemicals that affect the seed germination and root growth of many plant species. Recent studies have indicated that the reduction of root growth by these allelochemicals is associated with premature cell wall lignification. We hypothesized that an influx of these compounds into the phenylpropanoid pathway increases the lignin monomer content and reduces the root growth. To confirm this hypothesis, we evaluated the effects of cinnamic, p-coumaric, caffeic, ferulic and sinapic acids on soybean root growth, lignin and the composition of p-hydroxyphenyl (H), guaiacyl (G) and syringyl (S) monomers. To this end, three-day-old seedlings were cultivated in nutrient solution with or without allelochemical (or selective enzymatic inhibitors of the phenylpropanoid pathway) in a growth chamber for 24 h. In general, the results showed that 1) cinnamic, p-coumaric, caffeic and ferulic acids reduced root growth and increased lignin content; 2) cinnamic and p-coumaric acids increased p-hydroxyphenyl (H) monomer content, whereas p-coumaric, caffeic and ferulic acids increased guaiacyl (G) content, and sinapic acid increased sinapyl (S) content; 3) when applied in conjunction with piperonylic acid (PIP, an inhibitor of the cinnamate 4-hydroxylase, C4H), cinnamic acid reduced H, G and S contents; and 4) when applied in conjunction with 3,4-(methylenedioxy)cinnamic acid (MDCA, an inhibitor of the 4-coumarate:CoA ligase, 4CL), p-coumaric acid reduced H, G and S contents, whereas caffeic, ferulic and sinapic acids reduced G and S contents. These results confirm our hypothesis that exogenously applied allelochemicals are channeled into the phenylpropanoid pathway causing excessive production of lignin and its main monomers. By consequence, an enhanced stiffening of the cell wall restricts soybean root growth.  相似文献   

9.
The synthesis of structured phenolic lipids by lipase-catalyzed transesterification of selected phenolic acids, including p-hydroxyphenyl acetic, p-coumaric, sinapic, ferulic and 3,4-dihydroxybenzoic acids, with triolein was investigated. The highest enzymatic activity (248?nmol esterified phenolic acid/g solid enzyme/min) and bioconversion (62%) was obtained for the transesterification of p-hydroxyphenyl acetic acid with triolein. In addition, the transesterification of p-coumaric with triolein resulted in a higher enzymatic activity (87?nmol esterified phenolic acid/g solid enzyme/min) and bioconversion (46%) than those obtained for the transesterfication of ferulic and sinapic acids. The results also showed that using p-hydroxyphenyl acetic, p-coumaric and ferulic acids as substrate, the maximum bioconversion of phenolic monoacylglycerols was close to that of phenolic diacylglycerols. Although p-coumaric acid had very low radical scavenging activity (2%) compared to that of ferulic acid (62%), the p-coumaroylated lipids demonstrated a higher scavenging potency (16%) than that of the feruloylated one (10%).  相似文献   

10.
A cell wall fraction isolated from epicotyls of Vigna angularis,which contained both ionically and covalently bound peroxidases,rapidly oxidized p-coumaric, caffeic and ferulic acids and slowlyoxidized sinapic acid. The oxidation of sinapic acid was greatlyenhanced in the presence of p-coumaric, caffeic or ferulic acid.Ascorbate (20 µM) inhibited the oxidation of ferulic acidby about 70% and completely inhibited the oxidation of p-coumaricand ferulic acids. The cell wall fraction was capable of bindingferulic and sinapic acids but not caffeic acid. p-Coumaric acidbound only slightly to cell walls. The oxidation of p-coumaricand ferulic acids by KCl-washed cell walls was inhibited byabout 60% and 10%, respectively, by 20 µM ascorbate, butthe oxidation of caffeic acid was completely inhibited by ascorbateat less than 20 µM. The oxidation of derivatives of hydroxycinnamicacid by peroxidases released from cell walls by washing with1 M KCl was completely inhibited by ascorbate. These resultssuggest that the inhibition by ascorbate depends on the substituentgroup of the phenyl ring of the derivatives of hydroxycinnamicacid when the oxidation reaction is catalyzed by cell wall-boundperoxidases and that the oxidation of sinapic acid is mediatedby phenoxyl radicals of derivatives of hydroxycinnamic acidother than sinapic acid. (Received December 2, 1993; Accepted March 3, 1994)  相似文献   

11.
Fusariosis, caused by the fungus Fusarium subglutinans f. sp. ananas (Syn. F. guttiforme), is one of the main phytosanitary threats to pineapple (Ananas comosus var. comosus). Identification of plant cell responses to pathogens is important in understanding the plant–pathogen relationship and establishing strategies to improve and select resistant cultivars. Studies of the structural properties and phenolic content of cell walls in resistant (Vitoria) and susceptible (Perola) pineapple cultivars, related to resistance to the fungus, were performed. The non-chlorophyll base of physiologically mature leaves was inoculated with a conidia suspension. Analyses were performed post-inoculation by light, atomic force, scanning and transmission electron microscopy, and measurement of cell wall-bound phenolic compounds. Non-inoculated leaves were used as controls to define the constitutive tissue characteristics. Analyses indicated that morphological differences, such as cell wall thickness, cicatrization process and lignification, were related to resistance to the pathogen. Atomic force microscopy indicated a considerable difference in the mechanical properties of the resistant and susceptible cultivars, with more structural integrity, associated with higher levels of cell wall-bound phenolics, found in the resistant cultivar. p-Coumaric and ferulic acids were shown to be the major phenolics bound to the cell walls and were found in higher amounts in the resistant cultivar. Leaves of the resistant cultivar had reduced fungal penetration and a faster and more effective cicatrization response compared to the susceptible cultivar.  相似文献   

12.
Summary Two different antibodies against bovine serum albumin (BSA)-p-coumaric acid-conjugates were produced and used to localize phenolic compounds in exines of pollen from different species,p-Coumaric acid (pC) was coupled to BSA either via the carboxy group (BSA-pC) or directly to the aromatic ring system (BSA-azopC). The polyclonal antibodies raised in rabbits were characterized by ELISA with homologous and heterologous antigens using turkey ovalbumin as carrier protein. The results showed that the two immune sera directed against BSA-pC and BSA-azo-pC, respectively, were specific forp-coumaric acid and structurally similar compounds. Only a very poor binding by acetic acid-ovalbumin-conjugates and no binding by turkey ovalbumin was detectable. The antibodies reacted with partially purified pollen walls and with highly purified exines. The intensity of the immune reaction was proved to be dependent upon the pollen source and the preparation of the pollen walls. Using light and electron microscopy, it was shown for the first time that, in the exines ofCucurbita maxima, antibody binding was predominantly observed in the region of the germ pore apertures, the outer foot layers, and in the micro- and macrospines. We conclude from this and other earlier published data that phenols are important structural compounds of sporopollenin.Abbrevations AA acetic acid - BA benzoic acid - BSA bovine serum albumin - BSA-azo-pC p-coumaric acid coupled in meta position to BSA by a diazo reaction - BSA-azo-pC I immune serum against BSA-azo-pC - BSA-pC p-coumaric acid coupled to BSA via the COOH-group - BSA-pC I immune serum against BSA-pC - FA ferulic acid - OVA ovalbunin from turkey - pC p-coumaric acid - pHY p-hydroxybenzoic acid - SA sinapic acid - SYA syringic acid - TAT TBS-azide-Tween-buffer - TFA trifluoroacetic acid - VA vanillic acid  相似文献   

13.
Cell walls from suspension cultures of parsley (Petroselinum crispum L.) induced with a fungal elicitor contained hydroxycinnamoyl ester groups presumably not bound to pectic polysaccharides. Extracts from these cells were separated into a range of low-molecular-weight compounds containing esterified ferulic and p-coumaric acid as well as glucose and some arabinose. Similar compounds also accumulated extracellularly in elicited cultures but only in the presence of the peroxidase inhibitor ascorbate, suggesting that they may represent the exported precursors for cell wall hydroxycinnamic acids. From cultures elicited in the presence of ascorbate, alkali released from the cell walls more ferulic, p-coumaric and p-hydroxybenzoic acid, as well as p-hydroxybenzaldehyde and vanillin, indicating that the corresponding wall phenolics can all become further cross-linked. Received: 6 September 1996 / Revision received: 10 March 1997 / Accepted: 10 April 1997  相似文献   

14.
Phenylalanine ammonia-lyase (PAL) activity, 11 phenolic acids and lignin accumulation in Matricaria chamomilla roots exposed to low (3 μM) and high (60 and 120 μM) levels of cadmium (Cd) or copper (Cu) for 7 days were investigated. Five derivatives of cinnamic acid (chlorogenic, p-coumaric, caffeic, ferulic and sinapic acids) and six derivatives of benzoic acid (protocatechuic, vanillic, syringic, p-hydroxybenzoic, salicylic acids and protocatechuic aldehyde) were detected. Accumulation of glycoside-bound phenolics (revealed by acid hydrolysis) was enhanced mainly towards the end of the experiment, being more expressive in Cu-treated roots. Interestingly, chlorogenic acid was extremely elevated by the highest Cu dose (21-fold higher than control) suggesting its involvement in antioxidative protection. All compounds, with the exception of chlorogenic acid, were detected in the cell wall bound fraction, but only benzoic acids were found in the ester-bound fraction (revealed by alkaline hydrolysis). Soluble phenolics were present in substantially higher amounts in Cu-treated roots and more Cu was retained there in comparison to Cd. Cu strongly elevated PAL activity (by 5.4- and 12.1-fold in 60 and 120 μM treatment, respectively) and lignin content (by 71 and 148%, respectively) after one day of treatment, indicating formation of a barrier against metal entrance. Cd had slighter effects, supporting its non-redox active properties. Taken together, different forms of phenolic metabolites play an important role in chamomile tolerance to metal excess and participate in active antioxidative protection.  相似文献   

15.
It was found that when Rhodotorula rubra IFO 0911 was grown in a phenylalanine medium, benzoic acid and p-hydroxybenzoic acid besides cinnamic acid were formed in the cultured both. The conversions of cinnamic acid into benzoic acid and of benzoic acid into p-hydroxybenzoic acid, and the degradation of p-hydroxybenzoic acid were demonstrated in intact cells of Rhodotorula rubra. These activities were observed in the cells grown on various media, including the medium containing no phenylalanine, and were found to be distributed widely in Rhodotorula. The cells of Rhodotorula rubra were also able to degrade p-coumaric acid, 3,4-dihydroxybenzoic acid (protocatechuic acid), p-hydroxyphenyl-acetic acid, 3-methoxy-4-hydroxycinnamic acid (ferulic acid) and 3-methoxy-4-hydroxybenzoic acid (vanillic acid). From these results, the metabolic pathways for phenylalanine and tyrosine in Rhodotorula were discussed.  相似文献   

16.
We investigated the effect of elicitation on cell wall strengthening in eggplant roots caused by 6 elicitors viz., chitosan (CH), salicylic acid (SA), methyl jasmonate, methyl salicylate and vitamins B2 and B12. Analysis of phenolic metabolites from eggplant roots by HPLC revealed presence of 6 major cell wall-bound phenolic compounds. They were 4-hydroxybenzoic acid (4-HBA), vanillic acid (VA), 4-hydroxybenzaldehyde (4-HBAld), vanillin (VAN), 4-coumaric acid (4-CA) and ferulic acid (FA). In eggplant roots, the concentrations of FA, VA and 4-HBA were 188.71, 113.64 and 109.42 μg/g DW, respectively, and they were higher than those of 4-HBAld, VAN and 4-CA. When elicited roots were analyzed by HPLC, quantitative differences could be clearly discerned in the amount of the phenolic compounds. After 48 h post-elicitation (hpe) in the presence of CH, the increase in 4-HBA, 4-CA and FA contents in cell wall was 2.6-, 2.8- and 3.0-fold, respectively, compared with control. After 72 hpe, in the presence of SA, the increase in 4-HBA, 4-CA and FA levels was 3.5-, 2.9- and 3.8-fold, respectively, compared with the control. As the elicitors have specific receptors in plants, it may be possible to utilize CH and SA for inducing resistance against important diseases in eggplant.  相似文献   

17.
The objective of this research was to investigate how ferulic and p-coumaric acids affect lipid and fatty acid composition during canola (Brassica napus L.) seed germination. Data showed that both compounds increased total lipid and fatty acid contents in the cotyledons during germination. The largest accumulation in lipids occurred at 1.0 mM p-coumaric acid with an increase in all unsaturated fatty acids. The results suggest that allelochemicals interfere in canola seed germination by reducing lipid mobilization.  相似文献   

18.
The latex of Hevea brasiliensis; clone PR 107, contains from 160 to 1100 μg total phenolics per ml. This wide variability is associated with season, tapping system and application or not of a stimulant (Ethrel). The following aglycones have been identified in hydrolysed extracts: vanillic, salicyclic, syringic, gentisic, p- and m-hydroxybenzoic and protocatechuic acids; scopoletin, aesculetin and coumarin; ferulic, sinapic, caffeic, o- and p-coumaric acids; quercetin and kaempferol; tyrosine and dihydroxyphenylalanine. Flavans and condensed tannins are also present in latex.  相似文献   

19.
Hydroxycinnamates are among the most widely distributed plant phenylpropanoids present in the free, conjugated-soluble and insoluble-bound forms. This review will focus on the occurrence, in vitro and in vivo antioxidant activities of ferulic, coumaric, caffeic and sinapic acids and their derivatives. Hydroxycinnamates are found in almost all food groups though they are abundant in cereals, legumes, oilseeds, fruits, vegetables and beverages and render antioxidant activity by scavenging hydroxyl radical, superoxide radical anion, several organic radicals, peroxyl radical, peroxinitrite and singlet oxygen, among others. Further, their antioxidant activity as chain breaking antioxidants and reducing agents is also notable. Ferulic acid and its derivatives such as ferulic acid ethyl ester, ferulic acid dehydrodimers, feruloyl glycosides and curcumin have demonstrated potent antioxidant activity in both in vitro and in vivo systems. Similarly, caffeic acid and some of its derivatives such as caffeic acid phenethyl ester, rosmarinic acid, and chlorogenic acid exhibit antioxidant activity. The highest antioxidant activity was observed for caffeic acid whereas p-coumaric acid had the least effect among major hydroxycinnamic acids. The importance of structural effects on the potency of antioxidant activity of hydroxycinnamates is discussed. While this review also shows the existence of substantial body of evidences for in vitro antioxidant activity of hydroxycinnamates, there is a clear gap for in vivo information, particularly for sinapic and p-coumaric acids and their derivatives. The role of grains, fruits, vegetables and red wine in disease risk reduction and health promotion could partly be attributed to their constituent hydroxycinnamates.  相似文献   

20.
Six anthocyanins were isolated from cell suspension cultures of an Afghan cultivar of Daucus carota by PC or HPLC. The structures of these compounds were elucidated by spectroscopic methods as cyanidin 3-O-lathyroside, cyanidin 3-O-(2'-O-beta-D-xylopyranosyl-6'-O-beta-D-glucopyranosyl-beta-D- galactopyranoside), and the latter acylated with 4-coumaric, ferulic, 4-hydroxybenzoic or sinapic acid. Unusual 1H NMR chemical shifts and 1H NOE data indicate an intramolecular copigmentation of the aglycone with these aromatic residues.  相似文献   

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