scholarly journals 638 PB 366 EFFECTS OF PHENOLIC METABOLISM ON SUSCEPTIBILITY OF PEACH ROOTSTOCKS TO NEMATODES

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 524b-524
Author(s):  
Yuan Yongbing ◽  
A. M. Simeone ◽  
P. Cappelini

Peach rootstocks Rancho Resistant (RR) and GF 677 are resistant and susceptible to nematodes, respectively. One-year-old seedlings of RR, GF677 and their reciprocal grafts were inoculated with 10,000 larvae. Both inoculated and control plants were harvested at intervals for assay. Phenylalanine ammonia lyase (PAL) activity and soluble phenol content were enhanced in both RR and GF677 after inoculation, but RR always had a 2-fold higher peroxidase (PO) activity than GF677. When GF677 was grafted on RR, the resistance of RR was not altered. When RR was grafted onto GF677, the number of galls on the plant were 66% and 77% less than on GF677 2 weeks and 2 months after inoculation, respectively. However, no interaction was found in the reciprocal graft. The results showed that higher soluble phenol content and PAL activity induced by nematode attack were common features of RR and GF677, and a positive relation between PO activity and resistance to nematode existed in the two rootstocks.

Weed Science ◽  
1989 ◽  
Vol 37 (6) ◽  
pp. 743-747 ◽  
Author(s):  
Robert E. Hoagland

Three-day-old soybean seedlings were treated with acifluorfen via liquid culture [50 μM in dark, 1 μM in light (200 μE·m–2·s–1)]. Root elongation in the dark was inhibited only slightly (6%) after 96 h. In the light, acifluorfen inhibited root elongation after 48 h; after 96 h, inhibition was 32%. Hypocotyl length was not affected in either the light or dark. Soluble hydroxyphenolic content per axis was unaffected in the dark but was reduced by about 13 to 25% at 24 to 96 h in the light. Extractable phenylalanine ammonia-lyase (PAL, EC 4.3.1.5) activity per axis was unaltered by herbicide in the dark. A brief transient increase in PAL activity (4 to 24 h) in axes of light-grown seedlings in the presence of acifluorfen was followed by reduced enzyme levels compared to light-grown controls at 72 and 96 h. Although light is required for maximal herbicide action, there was no effect on anthocyanin or chlorophyll accumulation or on the chlorophyll a/b ratio in hypocotyls or light-grown seedlings.


HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1131B-1131
Author(s):  
Mikal Saltveit ◽  
Youngjun Choi ◽  
Francisco Tomás-Barberán

A wound signal originates at the site of injury in lettuce [Lactucasativa (L.)] leaf tissue and propagates into adjacent tissue where it induces a number of physiological responses that include increased phenolic metabolism with the de novo synthesis of phenylalanine ammonia lyase (PAL, EC 4.3.1.5), the synthesis and accumulation of soluble phenolic compounds (e.g., chlorogenic acid), and subsequent tissue browning. Exposing excised mid-rib leaf tissue to vapors (20 μmol·g-1 FW) or aqueous solutions (100 mm) of n-alcohols inhibited this wound-induced tissue browning by 40% and 60%, respectively. Effectiveness of the alcohol increased linearly from ethanol to the seven-carbon heptanol, and then was lost for the longer n-alcohols 1-octanol and 1-nonanol. The 2- and 3-isomers of the effective alcohols did not significantly reduce wound-induced phenolic accumulation at optimal 1-alcohol concentrations, but significant reductions did occur at much higher concentrations (100 μmol·g-1 FW) of the 2-, and 3-isomers. The active n-alcohols were maximally effective when applied during the first 2 h after excision, and were ineffective if applied 12 h after excision. Phospholipase D (PLD) and its product phosphatidic acid (PA) are thought to initiate the oxylipin pathway that culminates in the production of jasmonic acid, and PLD is specifically inhibited by 1-butanol, but not by 2- or 3-butanol. These results suggest that PLD, PA, and the oxylipin pathway may be involved in producing the wound signal responsible for increased wound-induced PAL activity, phenolic accumulation, and browning in fresh-cut lettuce leaf tissue.


1998 ◽  
Vol 123 (4) ◽  
pp. 687-691 ◽  
Author(s):  
Galen Peiser ◽  
Gloria López-Gálvez ◽  
Marita Cantwell ◽  
Mikal E. Saltveit

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.


HortScience ◽  
1990 ◽  
Vol 25 (11) ◽  
pp. 1356H-1357 ◽  
Author(s):  
Hendrik van Gorsel ◽  
Adel A. Kader

Internal breakdown (IB) is the limiting factor in the storage and postharvest handling of stone fruits. The symptoms of IB appear when fruits are kept for prolonged periods at temperatures below 10C and include leatheriness, mealiness, browning and bleeding of the flesh, and failure to ripen normally. We investigated the changes in phenolic compounds associated with IB of stone fruits. Twenty-eight phenolic compounds were separated by HPLC. Ten of these components were significantly affected by chilling temperatures. The concentration of six phenols changed in response to ripening after chilling temperatures, parallel to the appearance of IB symptoms. Most phenols showed a concentration gradient from the inside to the outside of the fruit, Comparison between peach cultivars showed characteristic differences in phenol metabolism during ripening. In both cultivars the most predominant phenol, chlorogenic acid, showed little change in concentration during storage. The structure of key phenolic compounds will be determined in order to elucidate the biochemical relationship between the phenols and the related enzymes. In this respect, a method was developed to detect phenylalanine ammonia-lyase (PAL) activity in peach fruit.


HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 526C-526
Author(s):  
Julio G. Loaiza-Velarde ◽  
Mikal E. Saltveit

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.


Author(s):  
Antonia Raya-Tena ◽  
María Isabel Fernández-San-Martin ◽  
Jaume Martin-Royo ◽  
Rocío Casañas ◽  
Glòria Sauch-Valmaña ◽  
...  

The association between physical illness and depression implies a poorer management of chronic disease and a lower response to antidepressant treatments. Our study evaluates the effectiveness of a psychoeducational group intervention led by Primary Care (PC) nurses, aimed at patients of this kind. It is a randomized, multicenter clinical trial with intervention (IG) and control groups (CG), blind response variables, and a one year follow-up. The study included 380 patients ≥50 years of age from 18 PC teams. The participants presented depression (BDI-II > 12) and a physical comorbidity: diabetes mellitus type 2, ischemic heart disease, chronic obstructive pulmonary disease, and/or asthma. The IG (n = 204) received the psychoeducational intervention (12 weekly sessions of 90 min), and the CG (n = 176) had standard care. The patients were evaluated at baseline, and at 4 and 12 months. The main outcome measures were clinical remission of depressive symptoms (BDI-II ≤ 13) and therapeutic response (reduction of depressive symptoms by 50%). Remission was not significant at four months. At 12 months it was 53.9% in the IG and 41.5% in the CG. (OR = 0.61, 95% CI, 0.49–0.76). At 4 months the response in the IG (OR = 0.59, 95% CI, 0.44–0.78) was significant, but not at 12 months. The psychoeducational group intervention led by PC nurses for individuals with depression and physical comorbidity has been shown to be effective for remission at long-term and for therapeutic response at short-term.


Electronics ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1208
Author(s):  
Francisco Alonso ◽  
Mireia Faus ◽  
Cristina Esteban ◽  
Sergio A. Useche

Technological devices are becoming more and more integrated in the management and control of traffic in big cities. The population perceives the benefits provided by these systems, and, therefore, citizens usually have a favorable opinion of them. However, emerging countries, which have fewer available infrastructures, could present a certain lack of trust. The objective of this work is to detect the level of knowledge and predisposition towards the use of new technologies in the transportation field of the Dominican Republic. For this study, the National Survey on Mobility was administered to a sample of Dominican citizens, proportional to the ONE census and to sex, age and province. The knowledge of ITS topics, as well as the use of mobile applications for mobility, are scarce; however, there was a significant increase that can be observed in only one year. Moreover, technology is, in general, positively assessed for what concerns the improvement of the traffic field, even though there is a lack of predisposition to provide one’s personal data, which is necessary for these devices. The process of technological development in the country must be backed up by laws that protect the citizens’ privacy. Thus, technologies that can improve road safety, mobility and sustainability can be implemented in the country.


Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 572
Author(s):  
Domenico Dalessandri ◽  
Marino Bindi ◽  
Francesca Massetti ◽  
Gaetano Isola ◽  
Marco Migliorati ◽  
...  

The risk of developing white spot lesions (WSLs) after orthodontic treatment with lingual brackets is generally considered lower than with labial ones, even if plaque accumulation is frequently higher due to the increased difficulty level in oral hygiene maintenance. In this prospective clinical study, selective enamel etching technique effectiveness in reducing plaque accumulation and WSLs was tested. Thirty patients were bonded with a split-mouth approach: two randomly selected opposite quadrants were used as the test sides, using customized plastic etching guides, and the other two as control sides, applying traditional direct etching methods. The plaque presence around the braces was recorded after 1, 3, 6, and 12 months according to a lingual plaque accumulation index (LPAI), as was the presence of WSLs. PAI measured values were significantly higher in the control sides during the observation period. Test and control sides differed significantly for new WSL onset only after 12 months of treatment. Therefore, the present research demonstrated that this guided enamel etching technique allowed for significant reduction in plaque accumulation around the lingual brackets and reduced onset of white spots after one year of treatment.


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Sonja Gadzovska Simic ◽  
Oliver Tusevski ◽  
Stéphane Maury ◽  
Alain Delaunay ◽  
Claude Joseph ◽  
...  

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.


2015 ◽  
Vol 73 (8) ◽  
pp. 648-654 ◽  
Author(s):  
Marcos C. Lange ◽  
Norberto L. Cabral ◽  
Carla H. C. Moro ◽  
Alexandre L. Longo ◽  
Anderson R. Gonçalves ◽  
...  

Aims To measure the incidence and mortality rates of ischemic stroke (IS) subtypes in Joinville, Brazil. Methods All first-ever IS patients that occurred in Joinville from January 2005 to December 2006 were identified. The IS subtypes were classified by the TOAST criteria, and the patients were followed-up for one year after IS onset. Results The age-adjusted incidence per 100,000 inhabitants was 26 (17-39) for large-artery atherosclerosis (LAA), 17 (11-27) for cardioembolic (CE), 29 (20-41) for small vessel occlusion (SVO), 2 (0.6-7) for stroke of other determined etiology (OTH) and 30 (20-43) for stroke of undetermined etiology (UND). The 1-year mortality rate per 100,000 inhabitants was 5 (2-11) for LAA, 6 (3-13) for CE, 1 (0.1-6) for SVO, 0.2 (0-0.9) for OTH and 9 (4-17) for UND. Conclusion In the population of Joinville, the incidences of IS subtypes were similar to those found in other populations. These findings highlight the importance of better detection and control of atherosclerotic risk factors.


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