Activity of phenylalanine ammonia-lyase, peroxidase and polyphenol oxidase in roots of banana (Musa acuminata AAA, cvs Grande Naine and Yangambi km5) before and after infection with Radopholus similis

Nematology ◽  
2006 ◽  
Vol 8 (2) ◽  
pp. 201-209 ◽  
Author(s):  
Nathalie Wuyts ◽  
Rony Swennen ◽  
Dirk De Waele
Keyword(s):  
Polyphenol Oxidase ◽  
Phenylalanine Ammonia Lyase ◽  
Phenylpropanoid Pathway ◽  
Musa Acuminata ◽  
Resistant Cultivar ◽  
Radopholus Similis ◽  
Wound Induction ◽  
Pal Activity ◽  
Before And After ◽  
Burrowing Nematode

AbstractPhenylpropanoids – phenolic compounds – take part in the wound and defence responses of plants and are frequently correlated with resistance. Enzymes directly or indirectly functional in the phenylpropanoid pathway are induced in plants in response to wounding and infection by pathogens, including sedentary endoparasitic nematodes. The activity of three of these enzymes, phenylalanine ammonia-lyase (PAL), peroxidase (PO) and polyphenol oxidase (PPO), was analysed in banana roots before and 1, 3 and 7 days after inoculation with the burrowing nematode Radopholus similis and in comparison with mechanically wounded roots. Constitutive activities of PAL, PO and PPO were lower in the resistant cv. Yangambi km5 (Musa acuminata AAA) than in the susceptible cv. Grande Naine (Musa acuminata AAA). During the experiment, levels increased to those of cv. Grande Naine, but only for R. similis-inoculated roots of cv. Yangambi km5 enzyme activities at 3 and 7 days after the onset of the experiment were values significantly higher than constitutive ones. At 7 days after the treatments, PO activity was significantly higher in wounded roots of cv. Grande Naine than in control and nematode-inoculated roots. The level of PAL activity in nematode-treated roots of cv. Yangambi km5 at 7 days after inoculation was 2.3-fold higher than control and wounded roots and up to six-fold higher than cv. Grande Naine roots. We concluded that PAL was induced in R. similis-inoculated roots of the resistant cultivar only and that this response was different from wound induction. For PO and PPO we concluded that levels in the resistant cultivar increased to those of the susceptible cultivar as a response to general stress in the plants during the experiment. Nevertheless, final levels of PO and PPO activity in R. similis-inoculated roots of the resistant cultivar were significantly higher than constitutive ones.

Effect of Fusarium oxysporum endophyte inoculation on the activities of phenylpropanoid pathway enzymes and Radopholus similis numbers in susceptible and tolerant East African Highland bananas

Nematology ◽  
2010 ◽  
Vol 12 (3) ◽  
pp. 469-480 ◽  
Author(s):  
Daniel Coyne ◽  
Thomas Dubois ◽  
Pamela Paparu ◽  
Altus Viljoen
Keyword(s):  
Wound Healing ◽  
Fusarium Oxysporum ◽  
Plant Defence ◽  
Constitutive Expression ◽  
Phenylpropanoid Pathway ◽  
Radopholus Similis ◽  
East African ◽  
Antagonistic Effects ◽  
Pal Activity ◽  
Burrowing Nematode

AbstractPhenylpropanoid pathway enzymes are involved in plant defence pathways leading to lignification, synthesis of secondary metabolites, such as salicylic acid and phytoalexins, wound healing and the oxidative burst. Endophytic non-pathogenic Fusarium oxysporum isolate V5w2 has been reported to show antagonistic effects against Radopholus similis in the screenhouse. An experiment was designed to study root biochemical changes (PAL, POX and PPO activities) and R. similis numbers in susceptible and tolerant bananas following inoculation with isolate V5w2. Constitutive expression of PAL and PPO were similar between the susceptible and tolerant cultivars, while constitutive POX activity was higher in the tolerant cultivar. PAL activity was suppressed in both cultivars 7 days after endophyte inoculation (7 dai), but was significantly up-regulated in the susceptible cv. Nabusa at 30 days post nematode challenge (dpnc) in endophyte-inoculated plants. In the tolerant cultivar, PAL activity was up-regulated in R. similis-challenged plants at 7 and 30 dpnc, irrespective of endophyte inoculation. POX and PPO were transiently up-regulated in cv. Nabusa 7 dai, exceeding levels observed in non-inoculated plants of the same cultivar. POX activity was up-regulated at 7 dpnc in endophyte-inoculated cv. Nabusa plants challenged with R. similis. In the tolerant cultivar, POX and PPO activities were similarly up-regulated in R. similis-challenged plants at 7 dpnc, irrespective of endophyte inoculation. The findings of this study implicate PAL, POX and PPO in banana defence against the root-burrowing nematode R. similis. Our findings further demonstrate the ability of endophytic F. oxysporum isolate V5w2 directly to induce POX and prime PAL in the susceptible cv. Nabusa for greater up-regulation following R. similis challenge.

scholarly journals Monitoring of the PAL Enzymatic Activity and Polyphenolic Compounds in Leaves and Fruits of Two Myrtle Cultivars during Maturation

Agriculture ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 389
Author(s):  
Silvia Medda ◽  
Leonarda Dessena ◽  
Maurizio Mulas
Keyword(s):  
Phenolic Compounds ◽  
Phenylalanine Ammonia Lyase ◽  
Raw Materials ◽  
Phenylpropanoid Pathway ◽  
Polyphenolic Compounds ◽  
Antioxidant Compounds ◽  
Total Polyphenols ◽  
Spectrophotometric Methods ◽  
Pal Activity ◽  
Potential Use

The leaves and berries of myrtle (Myrtus communis L.) are rich in phenolic compounds, such as phenolic acids, flavonoids, and flavanols. The richness of these antioxidant compounds allows the potential use of myrtle biomasses as raw materials for medicinal and functional food products. Most of the phenolic compounds originate from the phenylpropanoid pathway, where phenylalanine ammonia lyase (PAL) enzyme activates the first step. The objective of this research is to study the activity of PAL as related to accumulation in the myrtle fruits and leaves of some phenolic compounds in the period between blossom and full berry ripening. With this aim, we compared two model genotypes with different fruit coloration. In leaves and berries of two cultivars, ‘Giovanna’ with pigmented berries and ‘Grazia’ with white berries, the PAL activity and content of polyphenols, anthocyanins, flavonoids, and tannins were determined with spectrophotometric methods. PAL activity was quite constant in leaves and variable in berries: Greater in berries of ‘Giovanna’ than in those of ‘Grazia’ cultivar, and increasing from berry color-break to full ripening. In berries, a positive correlation between PAL and flavonoids (r = 0.44), and between PAL and anthocyanins (r = 0.69), as well as a negative correlation between PAL and total polyphenols (r = −0.471), were found.

scholarly journals 932 PB 530 PAL INDUCTION AND FRESH-CUT LETTUCE QUALITY

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 567f-567
Author(s):  
Gloria Lopez-Galvez ◽  
Mikal Saltveit ◽  
Marita Cantwel
Keyword(s):  
Fungal Infection ◽  
Lactuca Sativa ◽  
Phenylalanine Ammonia Lyase ◽  
Visual Quality ◽  
Wound Induction ◽  
Pal Activity ◽  
Iceberg Lettuce ◽  
Fresh Cut ◽  
Humidified Air ◽  
Kinetics Of

Phenylalanine ammonia-lyase (PAL) activity in iceberg lettuce (Lactuca sativa L.) is increased in response to several kinds of stress, including wounding, exposure to ethylene, and fungal infection. Ethylene-induced PAL activity is correlated with the discoloration and shelf-life of fresh cut lettuce (Couture et al. 1993. HortScience 28:723). The objective of this research was to further characterize the kinetics of wound-induced PAL in fresh cut lettuce. Leaves of different cvs were cut into salad pieces (1.5 × 3 cm), rinsed in chlorinated water, centrifuged manually, and placed into containers at 5 or 15C through which humidified air flowed. Samples were evaluated for overall visual quality and specific types of discoloration. Midrib tissue was also finely cut (1 × 0.5 cm) for enhanced wound-induction of PAL, which was assayed spectrophotometrically. The kinetics of PAL in midrib tissue of fine cut and salad cut lettuce were similar, with maximum activities obtained within 12-16 h at 15C and within 40-60 h at 5C. Maximum PAL levels in the fine cut lettuce were 1.5-2.0 times those observed in the salad cut pieces, and similar to those induced by ethylene. The usefulness of PAL as a predictor of the storage life of fresh cut lettuce depends on simplifying and expediting the PAL assay.

scholarly journals Role of Polyphenol Oxidase, Peroxidase, Phenylalanine Ammonia Lyase, Chlorogenic Acid, and Total Soluble Phenols in Resistance of Potatoes to Soft Rot

Plant Disease ◽  
2012 ◽  
Vol 96 (2) ◽  
pp. 186-192 ◽  
Author(s):  
Elizabeth Ngadze ◽  
David Icishahayo ◽  
Teresa A. Coutinho ◽  
Jacquie E. van der Waals
Keyword(s):  
Enzyme Activity ◽  
Chlorogenic Acid ◽  
Polyphenol Oxidase ◽  
Phenylalanine Ammonia Lyase ◽  
Soft Rot ◽  
Defense Responses ◽  
Bacterial Invasion ◽  
Pal Activity ◽  
Soluble Phenols

Pectobacterium atrosepticum, P. carotovorum subsp. brasiliensis, and Dickeya spp. cause soft rot of potato (Solanum tuberosum) worldwide. Plants respond to bacterial invasion by activating defense responses associated with accumulation of several enzymes and inhibitors, which prevent pathogen infection. This study focused on the role of polyphenol oxidase (PPO), peroxidase (POD), phenylalanine ammonia lyase (PAL), chlorogenic acid, and total soluble phenols in imparting resistance to soft rot pathogens. Seven and 11 varieties grown by farmers in South Africa and Zimbabwe, respectively, were used in the study. The results showed significantly higher (P < 0.001) enzyme activity of PPO and PAL as well as higher concentrations of chlorogenic acid and total soluble phenols in Vanderplank, Pentland Dell, M69/11, Romano, M59/20, and MondialZw. PAL activity increased significantly with time in all varieties, and the highest activity was recorded 8 h after cutting. The resistance of the varieties was correlated with high PPO and PAL enzyme activity as well as increased concentrations of chlorogenic acid and total soluble phenols. PPO, POD, and PAL activities increased significantly in wounded and inoculated tubers. These findings show that PAL, PPO, POD, chlorogenic acid, and total soluble phenols play a role in imparting resistance to potato soft rot infection.

scholarly journals Activity of Phenylalanine Ammonia-Lyase (PAL) and Concentrations of Anthocyanins and Phenolics in Developing Strawberry Fruit

1991 ◽  
Vol 116 (5) ◽  
pp. 865-869 ◽  
Author(s):  
Guiwen W. Cheng ◽  
Patrick J. Breen
Keyword(s):  
Phenylalanine Ammonia Lyase ◽  
Maximum Level ◽  
Phenylpropanoid Pathway ◽  
Fragaria X Ananassa ◽  
Strawberry Fruit ◽  
Pal Activity ◽  
Soluble Phenols ◽  
Phenolic Substances ◽  
Rapid Drop ◽  
Second Peak

Studies on regulation of production of phenolics in strawberry (Fragaria X ananassa Duch,) fruit were initiated by monitoring phenylalanine ammonia-lyase (PAL) activity and levels of anthocyanins, flavonoids, tannins, and other soluble phenols throughout fruit ontogeny in `Tillikum'. PAL catalyzes the first step in the biosynthesis of phenylpropanoids, which are further modified into a wide variety of phenolic compounds. Peak in PAL activity (1 mol· s-1 = 1 kat) of 90 pkat· mg-1 protein was detected at 5 and 27 days after anthesis (DAA), when fruit was green and nearly ripe, respectively. PAL activity was only ≈10% of peak values in the white berry stage, when. fruit growth was most rapid. The second peak in PAL activity was followed by a rapid drop, to nearly zero in red-ripe fruit at 30 DAA. Total soluble phenols reached a maximum level soon after anthesis, just before the first peak in PAL activity, then declined to a low constant value well in advance of fruit ripening. Similar changes were observed in levels of tannins and flavonoids that, at anthesis, accounted for 44% and 51% of the soluble phenols, respectively. The concentration of anthocyanin was very low throughout most of fruit development, but beginning at 23 DAA it increased from <0.03 to >0.53 mg·g-1 fresh weight in 3 days. This accumulation paralleled the second rise in PAL activity. Accordingly, strawberry fruit have a developmental-dependent expression of PAL activity and accumulation of phenolic substances derived from the phenylpropanoid pathway.

scholarly journals Control of Nematodes and Black Weevils in Plantains

1969 ◽  
Vol 67 (3) ◽  
pp. 270-277
Author(s):  
J. Román ◽  
D. Oramas ◽  
J. Green ◽  
A. Torres
Keyword(s):  
Puerto Rico ◽  
Chemical Control ◽  
Musa Acuminata ◽  
The Other ◽  
Cosmopolites Sordidus ◽  
Radopholus Similis ◽  
Burrowing Nematode ◽  
Effective Doses ◽  
Useful Life ◽  
Better Than

The burrowing nematode, Radopholus similis, and the black weevil, Cosmopolites sordidus, are the most important economic pests of plantain, Musa acuminata x M. balbisiana, AAB, in Puerto Rico. Research carried out by this Station has demonstrated that chemical control of nematodes increases plantain production and the useful life of the plantation. Similar results have not been obtained with the black weevil even when research has been conducted toward this goal. Several nematicide-insecticides for the control of both pests have been tested. At the Fortuna Substation five pesticides were evaluated: Carbofuran 5G and 10G, Fensulfothion 15G, Ethoprop 10G, and Aldicarb 10G. Carbofuran 5G was evaluated at the rate of 42 g/plant applied every 4 months. The other pesticides were evaluated at 56 g/plant applied every 6 months. At the Corozal Substation Aldicarb 10G was evaluated at 4 doses (10, 15, 30, 45 g/plant) applied every 4 and 6 months. Carbofuran 10G at 56 g/plant applied every 6 months was included for comparison. At the Fortuna Substation, where only one crop was harvested with no significant differences in yields, the majority of the pesticide treatments controlled the nematodes. The black weevil was controlled only with Aldicarb, Ethoprop, and Fensulfothion. At Corozal, where two crops were harvested, all treatments were significantly better than the control; with the control of nematodes and weevils there was an increase in yield and suckers. The most effective doses and frequencies for the control of both pests were Aldicarb 10G at the rate of 30 and 45 g/plant applied every 4 months and at 30 g applied every 6 months.

scholarly journals Phenylalanine Ammonia-lyase Inhibitors Do Not Prevent Russet Spotting Lesion Development in Lettuce Midribs

1998 ◽  
Vol 123 (4) ◽  
pp. 687-691 ◽  
Author(s):  
Galen Peiser ◽  
Gloria López-Gálvez ◽  
Marita Cantwell ◽  
Mikal E. Saltveit
Keyword(s):  
Phenolic Compounds ◽  
Phenylalanine Ammonia Lyase ◽  
Phenylpropanoid Pathway ◽  
Aminooxyacetic Acid ◽  
Physiological Disorder ◽  
Phenolic Metabolism ◽  
Pal Activity ◽  
Iceberg Lettuce ◽  
Tartaric Acids ◽  
Lyase Activity

Russet spotting is a physiological disorder of lettuce (Lactuca sativa L.) caused by exposure to hormonal levels (<1 μL·L-1) of ethylene in air at ≈5 °C. Enhanced phenolic metabolism and the accumulation of phenolic compounds accompany the appearance of brown, oval lesions on the leaf midrib. Phenylalanine ammonia-lyase (PAL) is the first committed enzyme in the phenylpropanoid pathway. Three inhibitors of PAL activity [2-aminoindan-2-phosphonic acid (AIP), α-aminooxyacetic acid (AOA), and α-aminooxi-β-phenylpropionic acid (AOPP)] greatly reduced the accumulation of phenolic compounds and browning of lesions. At a concentration of 50 μm, AIP inhibited the formation of chlorogenic and dicaffeoyl tartaric acids in cut midribs of iceberg lettuce by 92% and 98%, respectively. AIP competitively inhibited PAL activity from a lettuce midrib homogenate with an apparent Ki of 22 nm. While the formation of phenolic compounds was strongly inhibited by AIP, the number of lesions associated with russet spotting was not affected. Only the color of the lesions was affected by AIP. In control midribs the russet spotting lesions were brown while those in the AIP-treated midribs were initially olive green and after 3 to 7 days these lesions turned the characteristic brown color. No tyrosine ammonia-lyase activity was detected in a homogenate of lettuce midrib tissue. These results indicate that the early development of russet spotting lesions is independent of the increase in PAL activity and phenolic compounds rather than an effect of these increases as previously suggested. However, accumulation of phenolic compounds does contribute to the subsequent browning symptoms indicative of russet spotting.

scholarly journals Activation of phenylpropanoid pathway in legume plants exposed to heavy metals. Part I. Effects of cadmium and lead on phenylalanine ammonia-lyase gene expression, enzyme activity and lignin content.

2011 ◽  
Vol 58 (2) ◽  
Author(s):  
Sylwia Pawlak-Sprada ◽  
Magdalena Arasimowicz-Jelonek ◽  
Magdalena Podgórska ◽  
Joanna Deckert
Keyword(s):  
Heavy Metals ◽  
Phenylalanine Ammonia Lyase ◽  
Lignin Content ◽  
Mrna Level ◽  
Transcript Level ◽  
Phenylpropanoid Pathway ◽  
Lupinus Luteus ◽  
Pal Activity ◽  
Species Specific ◽  
Cadmium And Lead

Species-specific changes in expression of phenylalanine ammonia-lyase (PAL) and lignin content were detected in roots of soybean (Glycine max L.) and lupine (Lupinus luteus L.) seedlings treated with different concentrations of cadmium (Cd(2+), 0-25 mg/l) or lead (Pb(2+), 0-350 mg/l). The stimulatory effect of both metals was observed in mRNA coding for PAL in soybean. In the case of lupine, changes of PAL mRNA level were dependent on the metal used: Cd(2+) caused a decrease, whereas Pb(2+) an increase of PAL transcript level. The activity of PAL was enhanced in both plant species at higher metal concentrations (15-25 mg/l of Cd(2+) or 150-350 mg/l of Pb(2+)); however it was not directly correlated with PAL mRNA. This suggests a transcriptional and posttranscriptional control of PAL expression under heavy metals stress. In soybean, Cd(2+) or Pb(2+) treatment increased lignin content, while in lupine the effect was opposite. The decreased lignin accumulation in lupine roots in response to heavy metals, despite an increased PAL activity, suggests that the activated phenylpropanoid pathway was involved in the synthesis of secondary metabolites other than lignin.

scholarly journals 473 Beneficial Effect of Heat-shock Treatments on Lettuce Applied before and after Wounding

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 526C-526
Author(s):  
Julio G. Loaiza-Velarde ◽  
Mikal E. Saltveit
Keyword(s):  
Heat Shock ◽  
Beneficial Effect ◽  
Phenylalanine Ammonia Lyase ◽  
Storage Temperature ◽  
Hot Water ◽  
Phenolic Metabolism ◽  
Chemical Damage ◽  
Pal Activity ◽  
Before And After ◽  
Water Treatments

Changes in phenolic metabolism are induced by minimally processing, which ultimately leads to the browning of lettuce tissue. Phenylalanine ammonia-lyase (PAL, EC 4.3.1.5.) is greatly influenced by storage temperature. Evaluation of PAL activity at temperatures going from 0 to 25 °C showed that peaks occurred sooner at higher temperatures but at lower levels. Heat-shock treatments (50 °C, 90 s) have a protective effect against browning, help to retain greenness of tissue, and decrease the production of phenolics when applied either after or before wounding. To achieve a considerable, beneficial effect from hot water treatments applied after wounding these should not be delayed more than 36 h. The best results for heat-shock treatments before wounding occurred when applied at ≈12 h before cutting the tissue. Although cycloheximide did reduce PAL activity in a similar pattern as heat-shock treatments, it did not prevent browning itself. Cycloheximide seems to cause some sort of chemical damage that promotes the browning of lettuce tissue. When cycloheximide was applied in combination with heat-shock treatments browning did not occur.

scholarly journals Effects of Polysaccharide Elicitors on Secondary Metabolite Production and Antioxidant Response inHypericum perforatumL. Shoot Cultures

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Sonja Gadzovska Simic ◽  
Oliver Tusevski ◽  
Stéphane Maury ◽  
Alain Delaunay ◽  
Claude Joseph ◽  
...  
Keyword(s):  
Phenylalanine Ammonia Lyase ◽  
Hypericum Perforatum ◽  
Total Phenolics ◽  
Antioxidant Properties ◽  
Redox System ◽  
Antioxidant Response ◽  
Defense Responses ◽  
Shoot Cultures ◽  
Significant Suppression ◽  
Pal Activity

The effects of polysaccharide elicitors such as chitin, pectin, and dextran on the production of phenylpropanoids (phenolics and flavonoids) and naphtodianthrones (hypericin and pseudohypericin) inHypericum perforatumshoot cultures were studied. Nonenzymatic antioxidant properties (NEAOP) and peroxidase (POD) activity were also observed in shoot extracts. The activities of phenylalanine ammonia lyase (PAL) and chalcone-flavanone isomerase (CHFI) were monitored to estimate channeling in phenylpropanoid/flavonoid pathways of elicited shoot cultures. A significant suppression of the production of total phenolics and flavonoids was observed in elicited shoots from day 14 to day 21 of postelicitation. This inhibition of phenylpropanoid production was probably due to the decrease in CHFI activity in elicited shoots. Pectin and dextran promoted accumulation of naphtodianthrones, particularly pseudohypericin, within 21 days of postelicitation. The enhanced accumulation of naphtodianthrones was positively correlated with an increase of PAL activity in elicited shoots. All tested elicitors induced NEAOP at day 7, while chitin and pectin showed increase in POD activity within the entire period of postelicitation. The POD activity was in significantly positive correlation with flavonoid and hypericin contents, suggesting a strong perturbation of the cell redox system and activation of defense responses in polysaccharide-elicitedH. perforatumshoot cultures.

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