scholarly journals EFFECT OF TIME/TEMPERATURE TREATMENTS ON PHENYLALANINE AMMONIA-LYASE ACTIVITY AND DEVELOPMENT OF RUSSET SPOTTING IN ICEBERG LETTUCE

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1127c-1127
Author(s):  
M.A. Ritenour ◽  
M.E. Saltveit ◽  
M.J. Ahrens
Keyword(s):  
Phenylalanine Ammonia Lyase ◽  
Phenolic Content ◽  
Subjective Evaluation ◽  
Pal Activity ◽  
Iceberg Lettuce ◽  
Lyase Activity ◽  
Highly Correlated ◽  
Phenylalanine Ammonia Lyase Activity ◽  
Kinetics Of ◽  
Practical Implications

Russet spotting (RS) is an important postharvest disorder in Iceberg lettuce (Lactuca sativa L.). Previous studies showed that RS is induced by exposure to ∼5 ppm (ul/l) ethylene at ∼5C for 3 days and is characterized by the appearance of 1 to 2 mm diam. oval, brown sunken spots along the midrib. Increases in phenylalanine ammonia-lyase (PAL) activity and phenolic content are highly correlated with RS development. Ethylene-induced PAL activity is much less at higher (12C) or lower (0C) temperatures. In this study isolated whole leaves were exposed to a log series of ethylene concentrations from 0.1 to 10 ppm at temperatures from 0.0C to 20C for up to 8 days. Tissue was transferred among these various treatments to investigate the kinetics of PAL induction, activity and deactivation, phenolic accumulation, and RS development. A subjective evaluation was then made of RS development using a 1 to 9 scoring system in which 1 was no RS, and then PAL activity and phenolic content were measured. Preliminary results indicate that ethylene-induced PAL activity was decreased more rapidly upon transfer to temperatures above 10C than to 0.0C. Accumulation of phenolic compounds and development of RS paralleled each other, and were positively related to PAL activity. Practical implications of these results will be discussed.

scholarly journals Effects of Temperature on Ethylene-induced Phenylalanine Ammonia Lyase Activity and Russet Spotting in Harvested Iceberg Lettuce

1995 ◽  
Vol 120 (1) ◽  
pp. 84-87 ◽  
Author(s):  
M.A. Ritenour ◽  
M.J. Ahrens ◽  
M.E. Saltveit
Keyword(s):  
Phenolic Compounds ◽  
Phenylalanine Ammonia Lyase ◽  
Rapid Decrease ◽  
Effect Of Temperature ◽  
Pal Activity ◽  
Iceberg Lettuce ◽  
Lyase Activity ◽  
Lag Period ◽  
Effects Of Temperature ◽  
Phenylalanine Ammonia Lyase Activity

Experiments were conducted to study the effect of temperature on the ethylene inducibility of phenylalanine ammonia lyase (PAL, EC 4.3.1.5) activity and the development of russet spotting (RS) in Iceberg lettuce (Lactucu sutiva L.). Tissue exposed to ethylene and held at 15 or 20C showed earlier hut lower peaks in PAL activity than tissue held at 5C. Accumulation of total soluble phenolic compounds, and the development of RS paralleled increases in PAL activity after a short lag period. Lettuce tissue transferred from 5 to 15C after 1 to 3 days showed later hut higher peaks in PAL activity than tissue continuously held at 15C. Transferring ethylene-exposed tissue to 0C before RS symptoms developed greatly limited further rise in PAL activity and RS development. Discontinuing ethylene exposure after 4 days resulted in a rapid decrease in PAL activity. Lettuce tissue exposed to ethylene for 4 days and then transferred from 5 to 0C after the development of moderate RS symptoms showed no difference in RS after 8 days compared to tissue stored continuously at 5C.

Effects of Herbicides on Growth and Extractable Phenylalanine Ammonia-Lyase Activity in Light- and Dark-Grown Soybean (Glycine max) Seedlings

Weed Science ◽  
1981 ◽  
Vol 29 (4) ◽  
pp. 433-439 ◽  
Author(s):  
Robert E. Hoagland ◽  
Stephen O. Duke
Keyword(s):  
Glycine Max ◽  
Phenylalanine Ammonia Lyase ◽  
Dry Weight ◽  
Root Tip ◽  
Continuous Darkness ◽  
Soybean Seedlings ◽  
Pal Activity ◽  
Lyase Activity ◽  
Phenylalanine Ammonia Lyase Activity

Effects of 16 herbicides representing 14 herbicide classes on growth and extractable phenylalanine ammonia-lyase (PAL, EC 4.3.1.5) were examined in light- and dark-grown soybean [Glycine max(L.) Merr. ‘Hill’] seedlings. High purity (96 to 100%) herbicides were supplied via aqueous culture at various concentrations: 0.5 mM amitrole (3-amino-s-triazole), 0.1 mM atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine], 0.07 mM diclofop-methyl {methyl ester of 2-[4-(2,4-dichlorophenoxy)phenoxy] propanoicacid}, 0.5 mM DSMA (disodium methanearsonate), 0.2 mM fenuron (1,1-dimethyl-3-phenylurea), 0.05 mM fluridone {1-methyl-3-phenyl-[3-(trifluoromethyl)phenyl]-4(1H)-pyridinone}, 0.5 mM MH (1,2-dihydro-3,6-pyridazinedione), 0.5 mM metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5(4H)-one], 1.8 μM nitralin [4-(methylsulfonyl)-2,6-dinitro-N,N-dipropylaniline], 0.5 mM norflurazon [4-chloro-5-(methylamino)-2-(α,α,α-trifluoro-m-tolyl)-3(2H)-pyridazinone], 0.05 mM paraquat (1,1′-dimethyl-4,4′-bipyridinium ion), 0.15 mM perfluidone {1,1,1-trifluoro-N-[2-methyl-4-(phenylsulfonyl)phenyl] methanesulfonamide}, 0.2 mM propanil (3′,4′-dichloropropionanilide), 0.1 mM propham (isopropyl carbanilate), 0.5 mM TCA (trichloroacetic acid), and 0.05 mM 2,4-D [(2,4-dichlorophenoxy)acetic acid]. Dark-grown soybean seedlings (3-day-old) were transferred to control solutions (2 mM CaSO4) or to herbicide solutions (in 2 mM CaSO4) and grown at 25 C in continuous white light (200 μE•m-2•s-1) or continuous darkness until harvested 24 or 48 h after transfer. After 48 h, growth (fresh weight, dry weight, elongation) was inhibited by most of the chemicals. Other signs of toxicity (necrosis, secondary root stunting, and root tip swelling) were noted for some treatments. Roots were most affected, although hypocotyls were generally not changed. Hypocotyl elongation was stimulated by atrazine, fluridone, and norflurazon after 48 h light. Extractable PAL activity from soybean axes was decreased by atrazine, fenuron, metribuzin, norflurazon, propanil, propham, and 2,4-D. Amitrole and paraquat were the only herbicides that increased extractable PAL activity. Other compounds tested had no effect on the enzyme. None of the herbicides significantly affected in vitro PAL activity.

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.

Effects of DPX-4189 (2-chloro-N-(4-methoxy-6-methyl-1,3,5-triazin-2-yl)aminocarbonyl)benzenesulfonamide) on anthocyanin synthesis, phenylalanine ammonia lyase activity, and ethylene production in soybean hypocotyls

1982 ◽  
Vol 60 (6) ◽  
pp. 741-745 ◽  
Author(s):  
Jeffrey C. Suttle ◽  
Donald R. Schreiner
Keyword(s):  
Ethylene Production ◽  
Phenylalanine Ammonia Lyase ◽  
Anthocyanin Synthesis ◽  
Anthocyanin Content ◽  
Anthocyanin Accumulation ◽  
Soybean Seedlings ◽  
Pal Activity ◽  
Lyase Activity ◽  
Endogenous Ethylene ◽  
Phenylalanine Ammonia Lyase Activity

The effects of the herbicide DPX-4189 (2-chloro-N-((4-methoxy-6-methyl-1,3,5-triazin-2-yl)aminocarbonyl)benzenesulfonamide) on anthocyanin accumulation, phenylalanine ammonia lyase (PAL) activity, and ethylene production in seedlings of soybean (Glycine max L.) were investigated. Application of 1 μg DPX-4189 per plant led to an increase in anthocyanin content in soybean hypocotyls. The increase in anthocyanin content became evident 4 days after application of the herbicide. Accompanying the increase in anthocyanin content was an eightfold increase in extractable PAL activity. An increase in endogenous ethylene evolution also accompanied the increase in anthocyanin content. Application of silver nitrate (an inhibitor of ethylene action) to herbicide-treated seedlings did not prevent the increase in anthocyanin content. Application of 2-chloroethylphosphonic acid (an ethylene-releasing compound) to soybean seedlings stimulated PAL activity but had no effect on anthocyanin content. These results indicated that ethylene did not play a role in DPX-4189 mediated anthocyanin accumulation.

Changes in L-phenylalanine ammonia-lyase activity and isoflavone phytoalexins accumulation in soybean seedlings infected with Sclerotinia sclerotiorum

2013 ◽  
Vol 8 (9) ◽  
pp. 921-929
Author(s):  
Djordje Malenčić ◽  
Jelena Cvejić ◽  
Vesna Tepavčević ◽  
Mira Bursać ◽  
Biljana Kiprovski ◽  
...  
Keyword(s):  
Glycine Max ◽  
Sclerotinia Sclerotiorum ◽  
Phenylalanine Ammonia Lyase ◽  
Soybean Seedlings ◽  
Soybean Cultivars ◽  
Pal Activity ◽  
Isoflavone Content ◽  
Lyase Activity ◽  
Glycine Max L ◽  
Phenylalanine Ammonia Lyase Activity

AbstractSoybean [Glycine max (L.) Merr.] cultivars (Meli, Alisa, Sava and 1511/99) were grown up to V1 phase (first trifoliate and one node above unifoliate) and then inoculated with Sclerotinia sclerotiorum (Lib.) de Bary under controlled conditions. Changes in L-phenylalanine ammonia-lyase (PAL) activity and isoflavone phytoalexins were recorded 12, 24, 48 and 72 h after the inoculation. Results showed an increase in PAL activity in all four examined soybean cultivars 48 h after the inoculation, being the highest in Alisa (2-fold higher). Different contents of total daidzein, genistein, glycitein and coumestrol were detected in all samples. Alisa and Sava increased their total isoflavone content (33.9% and 6.2% higher than control, respectively) as well as 1511/99, although 48 h after the inoculation its content decreased significantly. Meli exhibited the highest rate of coumestrol biosynthesis (72 h after the inoculation) and PAL activity (48 h after the inoculation). All investigated cultivars are invariably susceptible to this pathogen. Recorded changes could point to possible differences in mechanisms of tolerance among them.

scholarly journals Indole-3-acetic Acid (IAA) Content and Axillary Bud Development in Relation to Russet Spotting in Harvested Iceberg Lettuce

1996 ◽  
Vol 121 (3) ◽  
pp. 543-547 ◽  
Author(s):  
Mark A. Ritenour ◽  
Ellen G. Sutter ◽  
David M. Williams ◽  
Mikal E. Saltveit
Keyword(s):  
Phenylalanine Ammonia Lyase ◽  
Axillary Bud ◽  
Poor Correlation ◽  
Bud Development ◽  
Pal Activity ◽  
Iceberg Lettuce ◽  
Harvest Dates ◽  
Highly Correlated ◽  
Growing Conditions ◽  
Indole 3 Acetic Acid

This study was undertaken to determine if endogenous IAA content and axillary bud development correlate with phenylalanine ammonia-lyase (PAL) induction and russet spotting (RS) susceptibility among RS susceptible and resistant cultivars of Iceberg lettuce (Lactuca sativa L.). Final levels of ethylene-induced PAL activity and RS development were highly correlated among cultivars, field conditions, and harvest dates. Harvested Iceberg lettuce midribs contained relatively low amounts of free IAA (maximum of 5.2 ng·g-1 fresh weight). There was poor correlation between free IAA content in lettuce leaf midribs and final RS development among all cultivars, growing conditions, and harvest dates. Axillary bud development, as measured by the number of visible buds per head, bud weight, or bud length, were not significantly correlated with final RS development or midrib IAA content. Cultivars with higher initial free IAA content lost much of their IAA after 8 days storage at 5C in air ± ethylene.

Relationships Between Phenylalanine Ammonia-Lyase Activity and Physiological Responses of Soybean (Glycine max) Seedlings to Herbicides

Weed Science ◽  
1983 ◽  
Vol 31 (6) ◽  
pp. 845-852 ◽  
Author(s):  
Robert E. Hoagland ◽  
Stephen O. Duke
Keyword(s):  
Glycine Max ◽  
Soluble Protein ◽  
Phenylalanine Ammonia Lyase ◽  
Soybean Seedlings ◽  
Chemical Treatments ◽  
Pal Activity ◽  
Lyase Activity ◽  
Phenylalanine Ammonia Lyase Activity ◽  
Dichlorophenoxy Acetic Acid

The effects of 16 herbicides from 14 different chemical classes on levels of soluble protein, hydroxyphenolics, anthocyanin, and chlorophyll were determined in light- and dark-grown soybean [Glycine max(L.) Merr. ‘Hill’] seedlings. Growth-reducing concentrations of the herbicides were supplied to 3-day-old dark-grown soybean seedlings in liquid culture. Soluble protein (per axis) was reduced by fluridone {1-methyl-3-phenyl-5-[3-(trifluoromethyl)phenyl]-4(1H)-pyridinone}, paraquat (1,1′-dimethyl-4,4′-bipyridinium ion), perfluidone {1,1,1-trifluoro-N-[2-methyl-4-(phenylsulfonyl)phenyl] methanesulfonamide}, and propanil (3′,4′-dichloropropionanilide) 24 or 48 h after treatment. In light-grown plants, soluble hydroxyphenolic compound levels were decreased on a per axis basis after 48 h by all chemical treatments except by atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine], the methyl ester of diclofop {2-[4-(2,4-dichlorophenoxy)phenoxy] propanoate}, DSMA (disodium methanearsonate), fluridone, MH (1,2-dihydro-3,6-pyridazinedione), nitralin [4-(methylsulfonyl)-2,6-dinitro-N,N-dipropylaniline], TCA (trichloroacetic acid), and 2,4-D [(2,4-dichlorophenoxy)acetic acid]. Total chlorophyll content in hypocotyls of these seedlings was decreased by fluridone, metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5 (4H)-one], norflurazon [4-chloro-5-(methylamino)-2-(α,α,α-trifluoro-m-tolyl)-3 (2H)-pyridazinone], paraquat, and 2,4-D, but others had no significant effect. Anthocyanin accumulation in hypocotyls of 48-h light-grown seedlings was decreased by atrazine, fenuron (1,1-dimethyl-3-phenylurea), metribuzin, norflurazon, paraquat, propanil, and propham (isopropyl carbanilate). Phenylalanine ammonia-lyase (PAL) activity (previously reported work) was positively correlated with anthocyanin levels in tissues after treatment with these 16 herbicides, but not with glyphosate [N-(phosphonomethyl)glycine]. There was, however, no correlation between extractable PAL activity and chlorophyll, soluble hydroxyphenolic compounds, or soluble protein content. These results indicated that extracted PAL activities usually reflect relative in vivo activities and that PAL activity is limiting to phenylpropanoid synthesis in vivo.

scholarly journals Novel oligosaccharides isolated from Fusarium oxysporum L. rapidly induce PAL activity in Rubus cells.

2004 ◽  
Vol 51 (3) ◽  
pp. 625-634 ◽  
Author(s):  
Mihai Nita-Lazar ◽  
Alain Heyraud ◽  
Claude Gey ◽  
Isabelle Braccini ◽  
Yvette Lienart
Keyword(s):  
Fusarium Oxysporum ◽  
Defense Response ◽  
Phenylalanine Ammonia Lyase ◽  
Fast Atom Bombardment ◽  
Alkaline Treatment ◽  
Size Exclusion ◽  
Pal Activity ◽  
Exclusion Chromatography ◽  
Lyase Activity ◽  
Phenylalanine Ammonia Lyase Activity

Activation of the phenolic pathway is known to be part of a defense response against cell wall-derived elicitors from pathogens. Many examples of a defense response by increasing the synthesis of phenolic compound against the elicitor were demonstrated in the past, but the elicitor structure has so far been poorly characterized. Our results indicate that a disaccharide fraction containing the following structure: alpha-D-mannopyranosyl (1-->2)alpha/beta-D-glucopyranosyl and alpha-D-mannopyranosyl (1-->x) inositol, isolated from Fusarium oxysporum L., promotes rapid and transient phenylalanine ammonia lyase activity in Rubus fructicosus cells at nanomolar concentration. The disaccharides were isolated by size-exclusion chromatography directly from extracts obtained by alkaline treatment of F. oxysporum mycelium. Their structure was determined by 500-MHz-1H-NMR spectroscopy combined with methylation analysis and fast atom bombardment mass spectrometry.

scholarly journals Estimating Phenylalanine Ammonia-lyase Activity in Common Beans Inoculated with Sclerotinia sclerotiorum

HortScience ◽  
1993 ◽  
Vol 28 (9) ◽  
pp. 937-938 ◽  
Author(s):  
Phillip N. Miklas ◽  
Kenneth F. Grafton ◽  
Phillip E. McClean
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Phenylalanine Ammonia Lyase ◽  
White Mold ◽  
Breeding Line ◽  
Common Beans ◽  
Pal Activity ◽  
Lyase Activity ◽  
Physiological Resistance ◽  
Phenylalanine Ammonia Lyase Activity ◽  
Whole Plants

We investigated the partial physiological resistance (PPR) of common beans (Phaseolus vulgaris L.) to white mold disease caused by Sclerotinia sclerotiorum (Lib.) deBary. The activity of phenylalanine ammonia-lyase (PAL) was measured in detached stems inoculated with a growing mycelium of the pathogen. Noninoculated detached stems and whole plants were included as controls. Five bean cultivars-Upland, Bunsi, Sierra, UI-114, and Montcalm-and one breeding line-NY 5394-were tested; all varied in PPR to white mold disease. Greater PAL activity in the resistant NY 5394 than in the susceptible `Upland' suggests that PAL activity may be involved in the PPR of common beans to S. sclerotiorum.

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