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 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.

Role of Phenylalanine Ammonia Lyase and Polyphenol Oxidase in Host Resistance to Bacterial Wilt of Tomato

2009 ◽  
Vol 157 (9) ◽  
pp. 552-557 ◽  
Author(s):  
Shyanadrahalli Chandrashekaraiah Vanitha ◽  
Siddapura Ramachandrappa Niranjana ◽  
Sharanaiah Umesha
Keyword(s):  
Polyphenol Oxidase ◽  
Bacterial Wilt ◽  
Host Resistance ◽  
Phenylalanine Ammonia Lyase

Cuttings of the non-rooting rac tobacco mutant overaccumulate phenolic compounds

2002 ◽  
Vol 29 (1) ◽  
pp. 63 ◽  
Author(s):  
Odile Faivre-Rampant ◽  
Jean-Paul Charpentier ◽  
Claire Kevers ◽  
Jacques Dommes ◽  
Harry Van Onckelen ◽  
...  
Keyword(s):  
Chlorogenic Acid ◽  
Adventitious Roots ◽  
Phenylalanine Ammonia Lyase ◽  
Wild Type ◽  
Growth Limitation ◽  
Phenolic Contents ◽  
Pal Activity ◽  
Culture Cycle ◽  
Biochemical Analyses

The auxin and phenolic contents, as well as phenylalanine ammonia-lyase (PAL) activity, were determined in in vitro cultured shoots of the recalcitrant-to-root rac mutant of tobacco, and compared with wild-type shoots. The mutant and wild-type shoots showed similar auxin changes during the culture cycle, but with higher contents for the mutant. A transient peak of auxin (corresponding to the achievement of the rooting inductive phase) occurred at day 14 in both types of shoots, but earlier in the basal parts of the wild-type stems. The rac shoots contained more phenolics, corresponding with an increased PAL activity. The most abundant phenolic compound found in the two types of tobacco was chlorogenic acid, which was more abundant in the rac shoots. Rutin was also detected at a higher concentration in the mutant shoots. Basal parts of wild-type shoots treated with 10–3 M chlorogenic acid reacted by accumulating auxins and, unlike untreated controls, did not form adventitious roots. The relationships between these biochemical analyses in relation to the growth limitation of the rac mutant, and the inhibition of its root development, are discussed.

Resistance to downy mildew in pearl millet is associated with increased phenylalanine ammonia lyase activity

2005 ◽  
Vol 32 (3) ◽  
pp. 267 ◽  
Author(s):  
N. P. Geetha ◽  
K. N. Amruthesh ◽  
R. G. Sharathchandra ◽  
H. S. Shetty
Keyword(s):  
Enzyme Activity ◽  
Downy Mildew ◽  
Pearl Millet ◽  
Phenylalanine Ammonia Lyase ◽  
Cultured Cells ◽  
Enzyme Activation ◽  
Sclerospora Graminicola ◽  
Pathogen Infection ◽  
Pal Activity ◽  
Downy Mildew Disease

Phenylalanine ammonia lyase (PAL) activity was studied in pearl millet cultivars with different levels of resistance to the downy mildew disease caused by Sclerospora graminicola, an important oomycete pathogen. PAL activity was elevated in resistant host cultivar and decreased in susceptible cultivars following downy mildew pathogen infection. The enzyme activation varied between cultivars and was correlated with the degree of resistance to downy mildew disease. The induction of PAL as a response to pathogen inoculation was further corroborated by a time-course study in seedlings and cultured cells of pearl millet. The level of PAL activity was highest at 1.5 h in cultured cells and 4 h in seedlings of resistant host cultivar after inoculation with Sclerospora graminicola. Further studies on PAL activity in different tissues of seedlings showed highest enzyme activity in the young growing region of the root of the resistant host cultivars. The accumulation of wall-bound phenolics and lignin was higher in the resistant cultivar seedlings as evidenced by phloroglucinol–HCl staining and p-coumaric acid assay. The temporal changes in lignin concentration and the concentration of soluble phenolics were greater in root tissues of resistant cultivars than in those of susceptible cultivars. Treatment of resistant seedlings with a PAL inhibitor, α-aminooxy-β-phenylpropionic acid, resulted in the enhancement of the enzyme activity, whereas in the presence of 1 mm trans-cinnamic acid the pathogen-induced PAL was completely inhibited. Treatment of pearl millet seedlings with exogenously applied PAL inhibitors induced downy mildew disease susceptibility in the resistant pearl millet cultivar, consistent with direct involvement of PAL in downy mildew resistance. Results are discussed with respect to the presumed importance of host phenolic compounds and lignin accumulation and its relation to PAL activation as a response to the pathogen infection.

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.

scholarly journals Induction of Chitinase, β-1,3-Glucanase, and Phenylalanine Ammonia Lyase in Peach Fruit by UV-C Treatment

2003 ◽  
Vol 93 (3) ◽  
pp. 349-355 ◽  
Author(s):  
Ahmed El Ghaouth ◽  
Charles L. Wilson ◽  
Ann M. Callahan
Keyword(s):  
Phenylalanine Ammonia Lyase ◽  
Defense Responses ◽  
Peach Fruit ◽  
Rapid Induction ◽  
Pal Activity ◽  
Induction Kinetic ◽  
Elicitor Treatment ◽  
Kinetic Pattern ◽  
A Minor ◽  
Uv C

Treatment of peach fruit with UV-C light caused a rapid induction of chitinase, β-1,3-glucanase, and phenylalanine ammonia lyase (PAL) activities starting 6 h after treatment and reaching maximum levels at 96 h after treatment. By 96 h after UV-C treatment, chitinase, β-1,3-glucanase, and PAL activities in UV-C-treated fruit were over twofold above the levels observed for the control. In nontreated control fruit, no apparent increase in chitinase and β-1,3-glucanase activities was detected but a minor increase in PAL activity was seen. The transient increase in chitinase, β-1,3-glucanase, and PAL activities in UV-C-treated fruit was preceded by a gradual activation of the corresponding genes. UV-C-treated fruit showed an increase in accumulation of β-1,3-glucanase and chitinase mRNAs at 3 h after treatment, which peaked approximately 96 h posttreatment. A similar induction kinetic pattern was observed for PAL mRNA in response to UV-C treatment, except the induction started 6 h after UV-C treatment. These results show that the response of peach fruit to elicitor treatment is similar to that seen in other plant-elicitors interactions and suggests the involvement of peach biochemical defense responses in UV-C-mediated disease resistance.

Differential Responses of Potato Cell Suspensions to a Culture Filtrate of Phytophthora infestans

1997 ◽  
Vol 52 (5-6) ◽  
pp. 333-338 ◽  
Author(s):  
M. F. M. Awan ◽  
U. Maciejewska ◽  
K. Kleczkowski ◽  
B. Wielgat
Keyword(s):  
Phytophthora Infestans ◽  
Culture Filtrate ◽  
Phenylalanine Ammonia Lyase ◽  
Solanum Tuberosum L ◽  
Defense Responses ◽  
Cell Suspensions ◽  
Plant Defense Responses ◽  
Polygenic Resistance ◽  
Pal Activity ◽  
Potato Cell

Abstract General (polygenic) resistance of plant hosts to an attack by a range of pathogens is an important feature of plant defense responses against the infection. In search of biochemical markers defining this resistance, cell suspensions derived from leaves of potato (Solanum tuberosum L .) cvs. Tarpan and Bzura that are polygenically susceptible and resistant to Phytophthora infestans, respectively, were inoculated with culture filtrate (CF) of the fungus. Cell suspension of Tarpan responded to CF treatment by a higher extracellular alkalinization and more significant reduction in their viability and growth than those of the Bzura cultivar. The stimulation of phenylalanine ammonia-lyase (PAL ) activity but not of β-1,3-glucanase, was significantly higher in CF treated Bzura cells than in Tarpan ones. The obtained results suggest that sensitivity to the fungal toxins and variation of PAL activity may represent useful markers for the evaluation of polygenic resistance in potato.

scholarly journals Regulation of Pear Color Development in Relation to Activity of Flavonoid Enzymes

2004 ◽  
Vol 129 (1) ◽  
pp. 6-12 ◽  
Author(s):  
W.J. Steyn ◽  
D.M. Holcroft ◽  
S.J.E. Wand ◽  
G. Jacobs
Keyword(s):  
Enzyme Activity ◽  
Fruit Development ◽  
Low Temperatures ◽  
Skin Color ◽  
Phenylalanine Ammonia Lyase ◽  
Effect Of Temperature ◽  
Immature Fruit ◽  
Pal Activity ◽  
Color Development ◽  
Red Color

Changes in activity of phenylalanine ammonia-lyase (PAL) and UDPGalactose: flavonoid-3-o-glycosyltransferase (UFGT) during the development of pear (Pyrus communis L.) fruit and in response to cold fronts were assessed and related to changes in red color. Red and blushed pear cultivars attained maximum redness and highest anthocyanin concentrations in immature fruit. Red color generally faded toward harvest. UFGT activity increased over fruit development and was apparently not limiting to color development. However, the fading of red color and the decreasing level of phenolic compounds toward harvest might relate to decreasing PAL activity. Skin color and enzyme activity in the red pear `Bon Rouge' displayed little responsiveness to low temperatures. In contrast, low temperatures increased red color and activity of both PAL and UFGT in the blushed pear `Rosemarie'. Consistent with the general pigmentation pattern described above, the effect of temperature on enzyme activity was much greater early during fruit development than in the week before harvest.

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.

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