scholarly journals Betacyanin accumulation and guaiacol peroxidase activity in Beta vulgaris L. leaves following copper stress

2012 ◽  
Vol 81 (3) ◽  
pp. 193-201 ◽  
Author(s):  
Janet M. León Morales ◽  
Mario Rodríguez-Monroy ◽  
Gabriela Sepúlveda-Jiménez

The effect of copper stress on betacyanin accumulation and guaiacol peroxidase (GPOD) activity in leaves of different age was evaluated in red beet (<em>Beta vulgaris </em>L. var. Crosby Egyptian) plants. In hydroponic culture, plants were treated with 0.3 μM (control), 50 μM, 100 μM, and 250 μM of CuSO<sub>4</sub> for 6 days. Copper was taken up and accumulated in old roots but was not translocated to leaves. However in young leaves, the increase of lipid peroxidation and reduction of growth were evident from day 3 of copper exposure; whereas in old leaves, the lipid peroxidation and growth were the same from either copper-treated or control plants. In response to copper exposure, the betacyanin accumulation was evident in young leaves by day 3, and continued to increase until day 6. Betacyanin only were accumulated in old leaves until day 6, but the contents were from 4 to 5 times lower than those observed in young leaves at the same copper concentrations. GPOD activity increased 3.3- and 1.4-fold in young and old leaves from day 3 of copper treatment respectively, but only in the young leaves was sustained at the same level until day 6. Old roots shown betacyanin in the control plants, but the betacyanin level and growth were reduced with the copper exposure. In contrast, young roots emerged by copper effect also accumulated copper and showed the highest betacyanin content of all plant parts assayed. These results indicate that betacyanin accumulation and GPOD activity are defense responses to copper stress in actively growing organs.

2020 ◽  
Vol 48 (3) ◽  
pp. 1260-1275
Author(s):  
Malihe JAHANI ◽  
Ramazan Ali KHAVARI-NEJAD ◽  
Homa MAHMOODZADEH ◽  
Sara SAADATMAND

Interaction of nanoparticles (NPs) as a significant threat to ecosystems with biological processes of plants is very important. Here, the effects of cobalt oxide (Co3O4) NPs on some physio-biochemical characteristics of Brassica napus L. were investigated. The two-weeks seedlings were sprayed with different concentrations of Co3O4 NPs (0, 50, 100, 250, 500, 1000, 2000, and 4000 mg L-1). The results showed that this treatment significantly affected the fresh and dry weights, area, relative water content (RWC) and relative chlorophyll value (SPAD) of leaves. The highest reduction of growth and biomass indexes occurred at 4000 mg L-1 NPs. The content of H2O2 and electrolyte leakage (EL) increased respectively, after 100 and 250 mg L-1 of Co3O4 NPs and showed a maximum level at 4000 mg L-1. The activities of phenylalanine ammonia lyase (PAL), ascorbate peroxidase (APX) and superoxide dismutase (SOD) increased after 100 mg L-1 of Co3O4 NPs. However, tyrosine ammonia lyase (TAL) activity enhanced after 500 mg L-1. The catalase (CAT) activity and protein content decreased after 1000 mg L-1 of Co3O4 NPs. Application of concentrations higher than 500 mg L-1 of Co3O4 NPs induced polyphenol oxidase (PPO) activity but reduced glutathione reductase (GR). The activities of guaiacol peroxidase (GPX) and glutathione S-transferase (GST) increased at 250-1000 mg L-1 of Co3O4 NPs and then decreased. These results suggested that low concentrations of Co3O4 NPs induced a positive effect on growth parameters but high levels caused extensive oxidative damage and mediated defense responses by organization of phenolic compounds and antioxidative system.


2020 ◽  
pp. 147-159
Author(s):  
Thangavelu Muthukumar ◽  
Selvam Dinesh-Babu

Investigamos el efecto de varias concentraciones (0,0-5,0 ppm) de cadmio (Cd) en la capacidad de regeneración; las características morfológicas y la acumulación de Cd en los esquejes de tallo de la verdura de hoja Talinum portulacifolium cultivada en cultivo hidropónico. El Cd retrasó la brotación de los esquejes en un 7%, la callosidad en un 8% y el enraizamiento en un 38%. Las diferentes concentraciones de Cd afectaron significativamente a los pesos fresco y seco de las partes de la planta, excepto las raíces. La acumulación de Cd fue mayor en los tallos que en las hojas (2,22 vs 0,57 ppm). El índice de tolerancia calculado osciló entre el 59% y el 88%. Basándose en las observaciones, se concluyó que el Cd interfiere con la regeneración de los esquejes de tallo de T. portulacifolium e implica preocupación sobre el consumo y el uso terapéutico de esta hortaliza de hoja que crece en suelos contaminados. We investigated the effect of various concentrations (0.0-5.0 ppm) of cadmium (Cd) on the regeneration ability; morphological characteristics and Cd accumulation in the leafy vegetable Talinum portulacifolium stem cuttings grown in hydroponic culture. Cd delayed sprouting of stem cuttings by 7%, callusing by 8% and rooting by 38%. Different Cd concentrations significantly affected fresh and dry weight of plant parts except roots. Accumulation of Cd was more in the stems than in leaves (2.22 vs 0.57 ppm). The calculated tolerance index ranged from 59% to 88%. Based on the observations it was concluded that Cd interferes with the regeneration of T. portulacifolium stem cuttings and imply concerns on the consumption and therapeutic use of this leafy vegetable growing on polluted soils.


2006 ◽  
Vol 131 (1) ◽  
pp. 110-117 ◽  
Author(s):  
D. Mark Hodges ◽  
Gene E. Lester

The consumption of netted muskmelons (Cucumis melo L. Reticulatus group) has raised health concerns due to pathogenic bacteria attaching to sites on the netted rind inaccessible to sanitation. The purpose of this study was to compare 1) the enzymic and nonenzymic antioxidant capacity between representative cultivars of netted muskmelon and both green- and orange-fleshed honey dew muskmelons during storage for 17 days and 2) levels of non-nutrient phytochemicals between these genotypes in consideration of ultimately substituting netted orange-fleshed with non-netted orange-fleshed muskmelon. Netted muskmelon (`Cruiser'), green-fleshed (`Honey Brew'), and orange-fleshed (`Orange Dew') muskmelons were harvested in Texas at the beginning (21 May) and at the end (11 June) of the production season in 2004. Fruit were analyzed immediately (day 0) or stored simulating retail conditions for 7 or 14 days at 7 °C and 95% ± 2% relative humidity plus 3 days at 21 °C. Both `Orange Dew' and `Honey Brew' non-netted cultivars evinced similar and less lipid peroxidation, and hence postharvest senescence, during the 17-day storage period than the netted muskmelon `Cruiser'. In comparison with `Cruiser', `Orange Dew' generally exhibited higher concentrations of ß-carotene and phenolics and, with few exceptions, higher activities of the antioxidant enzymes ascorbate peroxidase (AsPX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), catalase (CAT), guaiacol peroxidase (POX), and superoxide dismutase (SOD). Higher AsPX and SOD activities in both `Orange Dew' and `Honey Brew' appear to confer a greater resistance to lipid peroxidation in these muskmelon genotypes than to the netted `Cruiser'. `Orange Dew' also appears to be a healthier food choice not only due to its lack of a netted rind which could potentially harbour human illness-related pathogens, but also that it is superior to both `Cruiser' and `Honey Brew' in overall beta-carotene and phenolic levels.


Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1472
Author(s):  
Brigitta Tóth ◽  
Csaba Juhász ◽  
Maryke Labuschagne ◽  
Makoena Joyce Moloi

The recent study was conducted to examine the influence of acidic soil on the activities of ascorbate (APX) and guaiacol peroxidase (POD), proline, protein as well as malon-dialdehyde (MDA) content, in two commercial spring wheat cultivars (PAN3497 and SST806) at different growth stages (tillering and grain filling). A cultivar effect was significant only for MDA content, while the treatment effect was highly significant for proline, protein, and MDA. The sampling time effect was significant for most characteristics. MDA, antioxidative capacity, as well as protein content increased with maturity. At grain filling, MDA and proline contents were significantly higher at pH 5 than pH 6 and 7 for both cultivars, with the highest content in SST806. Similarly, SST806 had significantly higher APX and POD when growing at pH 5. There were no significant differences in protein content at grain filling between either genotype or treatments affected by low pH. This study showed that growth stage and soil pH influence the rate of lipid peroxidation as well as the antioxidative capacity of wheat, with a larger effect at grain filling, at pH 5. Although SST806 had higher proline, POD, and APX content than PAN3497 at this growth stage, this coincided with a very high MDA content. This shows that the high antioxidative capacity observed here, was not associated with a reduction of lipid peroxidation under low soil pH. Further research should, therefore, be done to establish the role of the induced antioxidant system in association with growth and yield in wheat.


Ecotoxicology ◽  
2019 ◽  
Vol 28 (9) ◽  
pp. 1075-1084 ◽  
Author(s):  
Cristiana Vaz ◽  
Fernando Afonso ◽  
Marisa Barata ◽  
Laura Ribeiro ◽  
Pedro Pousão-Ferreira ◽  
...  

Ecotoxicology ◽  
2019 ◽  
Vol 28 (8) ◽  
pp. 938-948 ◽  
Author(s):  
Laura Mincarelli ◽  
Luca Tiano ◽  
John Craft ◽  
Fabio Marcheggiani ◽  
Costantino Vischetti

1934 ◽  
Vol 11 (5) ◽  
pp. 582-588 ◽  
Author(s):  
T. Johnson ◽  
O. Johnson

In Part I of these studies it has been shown that the rapidly growing tissues of the wheat plant are more susceptible to stem rust than the older tissues. An attempt was made to discover if a physiological or chemical basis could be found for the difference in reaction of the young and older tissues.Analyses were made to determine the sugar content of young (susceptible) and older (resistant) tissues of four wheat varieties resistant in the adult stage and of the corresponding plant parts of three wheat varieties which in the adult stage showed little or no resistance to rust. The young tissues comprised the young leaves still enfolded by the uppermost sheaths and the young stems below the uppermost node; the older tissues were represented by the fully developed upper leaves and their adherent sheaths. The analyses showed a considerably higher content of sugars in the young than in the older tissues of the seven varieties tested. The difference was particularly great in the content of reducing sugars but rather slight in the disaccharide content (expressed as invert sugar). However, as all the varieties, irrespective of resistance or susceptibility to rust in the adult stage, showed much the same difference in the sugar content of their young and older tissues, it does not seem likely that there is any direct relation between sugar content and reaction to rust.


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