scholarly journals Effects of Zn and Cd accumulation on structural and physiological characteristics of barley plants

2007 ◽  
Vol 19 (1) ◽  
pp. 15-22 ◽  
Author(s):  
Balaji B. Maruthi Sridhar ◽  
Fengxiang X. Han ◽  
Susan V. Diehl ◽  
David L. Monts ◽  
Yi Su

The objectives of this study were to identify the structural changes caused by Zn and Cd accumulation in shoots and roots of barley (Hordeum vulgare) plants; and to correlate metal accumulation with anatomical, physiological and morphological changes. Potted plants were exposed to metal treatments of Zn and Cd for 19 and 16 d respectively. Leaves, stems and roots were harvested to identify structural changes and analyze metal accumulation. Barley effectively accumulated Zn (up to 11283 mg kg-1) and Cd (up to 584 mg kg-1) in the shoots. Microscopic structural changes, such as a decrease in intercellular spaces, breakdown of vascular bundles, and shrinkage of palisade and epidermal cells, occurred in leaves, stems and roots of plants treated with high concentrations of Zn. Zinc accumulation also resulted in a significant decrease in water content, fresh weight, dry weight and plant height. Cadmium only caused structural changes in roots at the higher concentrations. Barley plants were able to accumulate significant amounts of Zn and Cd without exhibiting symptoms of phytotoxicity when the metal concentrations were relatively low.

1997 ◽  
Vol 48 (2) ◽  
pp. 147 ◽  
Author(s):  
G. M. Smith ◽  
C. L. White

We determined the effects of increased dietary concentrations of molybdenum and sulfur on the accumulation and tissue concentrations of cadmium in sheep, and compared them with effects on copper. Forty sheep, each weighing approximately 40 kg, were adjusted for 3 weeks to a basal diet of 80% wheaten chaff and 20% lupin seed containing (per kg dry weight) 0·016 mg Cd, 0·45 mg Mo, 3·4 mg Cu, and 1·9 g S. On Day 0 of treatment, 8 sheep were killed and the tissues analysed for trace minerals to provide a baseline value. The remaining sheep were divided into 4 dietary treatment groups: control (basal diet plus 4 mg Cd/kg), +Mo (control diet plus 15 mg Mo/kg), +S (control diet plus 4 g S/kg), +Mo+S (control diet+15 mg Mo+4 g S/kg). The treatment period lasted 80 days, after which sheep were killed for tissue samples. Sulfur alone reduced the accumulation of Cd in liver, kidney, and muscle by 60% compared with control sheep (P < 0·05). Molybdenum alone reduced Cd accumulation by 40% in liver and muscle (P < 0·05) and 30% in kidney (P = 0·09). When provided together (+Mo+S), the effect was equivalent to feeding with Mo alone, showing that Mo blocked the effect of S. Cadmium concentrations in whole kidneys for the 4 respective treatments were 6·40 ± 0· 7, 2·8 ± 0·3, 4·5 ± 0·8, and 5·0 ± 0·5 mg/kg fresh weight. The pre-treatment concentration was 0·7 ± 0·2 mg/kg. For Cu in blood and tissues, the effects of Mo and S treatment were consistent with the thiomolybdate hypothesis, and were quite different from those seen for Cd. Copper concentrations in whole kidney for the 4 treatments were 4·1 ± 0·1, 3·5 ± 0·2, 4·7 ± 0·3, and 22·4 ± 3·9 mg/kg fresh weight. The pre-treatment concentration was 4·1 ± 0·3 mg/kg. The results show that increased dietary levels of Mo and S reduce the accumulation of Cd in tissues, and the mechanisms of action differ from those involving Cu.


2020 ◽  
Vol 63 (1) ◽  
pp. 22-29
Author(s):  
Jehan Bakht ◽  
Rafi Ullah ◽  
Mohammad Shafi

 The present study investigates the phyto-accumulation capacity of two cultivars of sunflower (Helianthus annuus L.) for heavy metals. Analysis of the data recorded ten weeks after sowing indicated that heavy metal application had significantly (p<0.05) affected all the parameters under study. Interaction of EDTA x cultivar and EDTA x cultivar x heavy metal had significantly (p<0.05) affected root fresh weight, root dry weight and heavy metal accumulation. EDTA application had significant (p<0.05) effect on heavy metal accumulation when data was noted ten weeks after sowing. The data also revealed that maximum plant height, number of leaves/plant, shoot fresh weight and dry weight, root fresh and dry weight was noted in control pots (0 mg/kg heavy metal). The suggested that maximum shoot fresh weight shoot dry weight, root fresh weight and root dry weight was noted in pots kept at control with San Sun-33 when applied with 5 mM EDTA. Similarly, maximum heavy metal accumulation was recorded in treatment sown of HiSun-33 applied with 5 mM EDTA and 50 mM chromium. Maximum root fresh weight was noted in control pots treated with 5 mM EDTA and planted with San Sun-33. Similarly, heavy metal accumulation was more in HiSun-33 treated with 50 mg/kg chromium and 5 mM EDTA. In terms of accumulation of heavy metals, HiSun-33 demonstrated better accumulation of the tested heavy metals then SanSun-33, anyhow the growth of SanSun-33 was better than HiSun-33 due to lesser accumulation of heavy metals.  


2016 ◽  
Vol 62 (2) ◽  
pp. 72-79 ◽  
Author(s):  
Beáta Piršelová ◽  
Roman Kuna ◽  
Peter Lukáč ◽  
Michaela Havrlentová

Abstract The influence of different concentrations of cadmium (Cd) ions (50 and 100 mg/kg soil) on growth, photosynthetic pigment content, Cd, and iron accumulation in faba bean (Vicia faba L. cv. Aštar) was studied under laboratory conditions. No significant changes were observed in the growth parameters of shoots (length, fresh, and dry weight). Both tested Cd doses resulted in decrease in root fresh weight by 31.7% and 28.68% and in dry weight by 32.2% and 33.33%, respectively. Increased accumulation of Cd was observed in roots (125- and 173-fold higher than in control) and shoots (125- and 150-fold higher than in control) as a result of applied doses of Cd. Increased accumulation of iron was detected in roots (1.45- and 1.69-fold higher than in control). Decrease in the content of chlorophyll a (by 25.52 and 24.83%, respectively) and chlorophyll b (by 6.90%) after application of Cd 100 as well as decrease in carotenoids (by 40.39 and 38.36%, respectively) was detected. Weak translocation of Cd from roots to shoots pointed to low phytoremediation potential of the tested bean variety in contaminated soil. However, the high tolerance of this cultivar, its relative fast growth, as well as priority of Cd accumulation in roots presume this plant species for phytostabilisation and revegetation of the Cd-contaminated soils.


1987 ◽  
Vol 14 (4) ◽  
pp. 463 ◽  
Author(s):  
P Boursier ◽  
J Lynch ◽  
A Lauchli ◽  
E Epstein

Chloride distribution in the blade, sheath and midrib of leaves was determined for several grasses in salinised field plots and in nutrient solutions at various NaCl levels in the greenhouse. Chloride preferentially accumulated in the sheaths relative to the blades in all grass species and varieties examined when Cl- concentrations were expressed on a dry weight basis, although to varying degrees. Substantial levels of Cl- sheath partitioning were obtained only for sorghum when Cl- con- centrations were expressed on a fresh weight basis. Partitioning of Cl- in sorghum leaves was found to be ion specific and resulted from a combination of the ability of sheath tissue to accumulate Cl- to high concentrations and blade tissue to regulate Cl- concentrations at moderate levels.


Author(s):  
A. Tilly Mándy ◽  
P. Honfi ◽  
É. Stefanovits-Bányai ◽  
I. D. Mosonyi ◽  
V. Köbli ◽  
...  

In recent work the effect of 5-aminolevulinic-acid (ALA) agent (commercial name Pentakeep-V) was examined on the chlorophyll content, growth and development of Saintpaulia ionantha. The newly re-rooted potted plants were irrigated or sprayed with 0.3‰ or 0.5‰ Pentakeep-V solution, and plus 30% long lasting fertilizer was added to half of the all treatments. Control plants were sprayed with tap water. Best result were obtained on the field of flowering. All the treatments promoted chlorophyll-content in the leaves especially spraying with 0.3‰concentration. Plants treated with Pentakeep-V in both concentrations and independently from the spraying or irrigation flowered more than two weeks earlier than control and those that got plus 30% fertilizer. Besides in the case of some treatments the diameter of leaf rosette, the number and surface size of leaves grew comparing to the control. The longlasting fertilizer had positive effect on the fresh weight but none of treatments had effect on the dry weight.


2021 ◽  
Vol 15 (1) ◽  
pp. 558-568
Author(s):  
Douglas Magno Guimarães ◽  
Brennda Lucy Freitas de Paula ◽  
Luciane Margalho Rodrigues ◽  
Hilton Túlio Costi ◽  
Hervé Louis Ghislain Rogez ◽  
...  

Background: The tooth bleaching treatment can cause structural changes in the surfaces of the teeth; these changes can increase the absorption of staining agents. Purpose: This study assessed surface morphological changes and predisposition to staining in dental enamel bleached with different hydrogen peroxide (HP) concentrations, with or without the use of a light source (LS). Methods: 25 bovine incisor specimens were divided into five groups (n = 5): Control- no treatment; HP35 - hydrogen peroxide 35%; HP35+LED - hydrogen peroxide 35% + light emission; HP20 - hydrogen peroxide 20%; and HP7 - hydrogen peroxide 7,5%. Twenty days after bleaching, the specimens were immersed in staining solutions four hours a day for 28 days. The morphological alterations of the bovine enamel surface were evaluated by means of scanning electron microscopy, X-ray dispersive energy spectroscopy and predisposition to the staining of the brightened enamel by means of colorimetry. Results: ANOVA with Tukey's test (p<0.05) showed that HP7 had the highest ΔL values (p=0.176) (brightest), with a better lightening effect. The bleached groups exhibited morphological changes in the enamel. The groups did not exhibit significant changes in oxygen, calcium, and phosphorus values (p=0.020). The presence or absence of light was not significant (p=0.007) for the predisposition to staining in bleached teeth. Conclusion: The time of exposure to the staining solution was significant for staining bovine dental enamel. High concentrations of HP were not necessary for achieving effective bleaching. HP caused an increase in enamel porosity and depressions. The light source did not influence bleaching.


1978 ◽  
Vol 56 (1) ◽  
pp. 123-131 ◽  
Author(s):  
J. E. Fox ◽  
T. F. McElligott ◽  
I. T. Beck

Glucose and water transport is depressed in the hamster jejunum in vivo by ethanol (4.8%) which also produced fluid-filled blebs at the tips of the villi. The epithelial cells over the blebs appeared stretched and cuboidal, the lateral intercellular spaces (LIS) were no longer recognizable, and the lacteals were closed. Forty-five minutes after discontinuation of the ethanol, water transport returned to normal while glucose transport remained depressed. At this time the villus structure had returned to normal. The blebs had disappeared, the LIS were again recognizable, and their appearance and number were similar to those in the control animals. Thus, the depression of water transport correlated with the obvious structural changes caused by ethanol; however, the depression of glucose absorption is associated with some effect of ethanol not evident by routine light microscopy.


Author(s):  
A.J. Mia ◽  
L.X. Oakford ◽  
T. Yorio

The amphibian urinary bladder has been used as a ‘model’ system for studies of the mechanism of action of antidiuretic hormone (ADH) in stimulating transepithelial water flow. The increase in water permeability is accompanied by morphological changes that include the stimulation of apical microvilli, mobilization of microtubules and microfilaments and vesicular membrane fusion events . It has been shown that alterations in the cytosolic calcium concentrations can inhibit ADH transmembrane water flow and induce alterations in the epithelial cell cytomorphology, including the cytoskeletal system . Recently, the subapical granules of the granular cell in the amphibian urinary bladder have been shown to contain high concentrations of calcium, and it was suggested that these cytoplasmic constituents may act as calcium storage sites for intracellular calcium homeostasis. The present study utilizes the calcium antagonist, verapamil, to examine the effect of calcium deprivation on the cytomorphological features of epithelial cells from amphibian urinary bladder, with particular emphasis on subapical granule and microfilament distribution.


2020 ◽  
Author(s):  
Katie Mae Wilson ◽  
Aurora Burkus-Matesevac ◽  
Samuel Maddox ◽  
Christopher Chouinard

β-methylamino-L-alanine (BMAA) has been linked to the development of neurodegenerative (ND) symptoms following chronic environmental exposure through water and dietary sources. The brains of those affected by this condition, often referred to as amyotrophic lateral sclerosis-parkinsonism-dementia complex (ALS-PDC), have exhibited the presence of plaques and neurofibrillary tangles (NFTs) from protein aggregation. Although numerous studies have sought to better understand the correlation between BMAA exposure and onset of ND symptoms, no definitive link has been identified. One prevailing hypothesis is that BMAA acts a small molecule ligand, complexing with critical proteins in the brain and reducing their function. The objective of this research was to investigate the effects of BMAA exposure on the native structure of ubiquitin. We hypothesized that formation of a Ubiquitin+BMAA noncovalent complex would alter the protein’s structure and folding and ultimately affect the ubiquitinproteasome system (UPS) and the unfolded protein response (UPR). Ion mobility-mass spectrometry revealed that at sufficiently high concentrations BMAA did in fact form a noncovalent complex with ubiquitin, however similar complexes were identified for a range of additional amino acids. Collision induced unfolding (CIU) was used to interrogate the unfolding dynamics of native ubiquitin and these Ubq-amino acid complexes and it was determined that complexation with BMAA led to a significant alteration in native protein size and conformation, and this complex required considerably more energy to unfold. This indicates that the complex remains more stable under native conditions and this may indicate that BMAA has attached to a critical binding location.


2020 ◽  
Author(s):  
Katie Mae Wilson ◽  
Aurora Burkus-Matesevac ◽  
Samuel Maddox ◽  
Christopher Chouinard

β-methylamino-L-alanine (BMAA) has been linked to the development of neurodegenerative (ND) symptoms following chronic environmental exposure through water and dietary sources. The brains of those affected by this condition, often referred to as amyotrophic lateral sclerosis-parkinsonism-dementia complex (ALS-PDC), have exhibited the presence of plaques and neurofibrillary tangles (NFTs) from protein aggregation. Although numerous studies have sought to better understand the correlation between BMAA exposure and onset of ND symptoms, no definitive link has been identified. One prevailing hypothesis is that BMAA acts a small molecule ligand, complexing with critical proteins in the brain and reducing their function. The objective of this research was to investigate the effects of BMAA exposure on the native structure of ubiquitin. We hypothesized that formation of a Ubiquitin+BMAA noncovalent complex would alter the protein’s structure and folding and ultimately affect the ubiquitinproteasome system (UPS) and the unfolded protein response (UPR). Ion mobility-mass spectrometry revealed that at sufficiently high concentrations BMAA did in fact form a noncovalent complex with ubiquitin, however similar complexes were identified for a range of additional amino acids. Collision induced unfolding (CIU) was used to interrogate the unfolding dynamics of native ubiquitin and these Ubq-amino acid complexes and it was determined that complexation with BMAA led to a significant alteration in native protein size and conformation, and this complex required considerably more energy to unfold. This indicates that the complex remains more stable under native conditions and this may indicate that BMAA has attached to a critical binding location.


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