Does long-term cadmium exposure influence the composition of pectic polysaccharides in the cell wall of Medicago sativa stems?

Accumulation of cadmium (Cd) shows a serious problem for the environment and poses a threat to plants. Plants employing various cellular and molecular mechanisms to limit Cd toxicity and alterations of the cell wall structure were observed upon Cd exposure. This study focuses on changes in the cell wall protein-enriched subproteome of alfalfa (Medicago sativa) leaves during long-term Cd exposure. Plants grew on Cd-contaminated soil (10 mg/kg dry weight (DW)) for an entire season. A targeted approach was used to sequentially extract cell wall protein-enriched fractions from the leaves and quantitative analyses were conducted with two-dimensional difference gel electrophoresis (2D DIGE) followed by protein identification with matrix-assisted laser desorption/ionization (MALDI) time-of-flight/time of flight (TOF/TOF) mass spectrometry. In 212 spots that showed a significant change in intensity upon Cd exposure a single protein was identified. Of these, 163 proteins are predicted to be secreted and involved in various physiological processes. Proteins of other subcellular localization were mainly chloroplastic and decreased in response to Cd, which confirms the Cd-induced disturbance of the photosynthesis. The observed changes indicate an active defence response against a Cd-induced oxidative burst and a restructuring of the cell wall, which is, however, different to what is observed in M. sativa stems and will be discussed.

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Changes of Renal Cadmium Accumulation Levels and Urinary Cadmium Excretion Levels Induced by Long-term Cadmium Exposure in Rats

Korean Journal of Occupational and Environmental Medicine ◽

10.35371/kjoem.1997.9.1.109 ◽

1997 ◽

Vol 9 (1) ◽

pp. 109

Author(s):

In Soon Song ◽

Yong Chae Cho ◽

Soo Young Kim ◽

Am Park ◽

Kyung Sun Son ◽

...

Keyword(s):

Cadmium Accumulation ◽

Cadmium Exposure ◽

Urinary Cadmium

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Ultrastructure of Medicago sativa rhizodermis cells over their early development

Biologia ◽

10.2478/s11756-008-0035-x ◽

2008 ◽

Vol 63 (2) ◽

Author(s):

Lucia Mikolajová ◽

Halina Vargová ◽

Zora Hanáčková ◽

Milada Čiamporová

Keyword(s):

Cell Wall ◽

Medicago Sativa ◽

Root Hair ◽

Phosphotungstic Acid ◽

Root Tip ◽

Cell Wall Polysaccharides ◽

Golgi Bodies ◽

Internalization Process ◽

Subcellular Level ◽

Root Hair Initiation

AbstractUltrastructure was investigated along the files of developing epidermal cells in the root tip of a model plant Medicago sativa, in which all rhizodermal cells are potential hair-forming trichoblasts. Differentiation at subcellular level was observed up to the stage of bulge initiation in the trichoblasts. Root hair initiation indicated by the emergence of bulges from trichoblasts was detected at various distances from the root tip and, it was independent of the trichoblast size.During rhizodermal cell differentiation, starch grains accumulated in the plastids. Nuclei located in the central part of the young, meristematic cells moved towards the inner periclinal wall as the central vacuole enlarged. The bulging region of the trichoblasts located opposite the nucleus and was rich in mitochondria, ER, ribosomes, and Golgi bodies, and contained also vesicles enclosing fibrillar material. This material responded positively to phosphotungstic acid, which was used for detection of cell wall polysaccharides. The cell wall thickness within the bulging domain was significantly lower than in other parts of trichoblasts. We suggest that internalization of cell wall polysaccharides occurs within the bulging area, contributing to local thinning of the cell wall and providing a source of osmotically active compounds for maintaining turgor in the trichoblast. Thus, the internalization process might be necessary for root hair outgrowth.

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Shearing force of alfalfa stems: Effects of genotype and year interactions

Canadian Journal of Animal Science ◽

10.4141/a97-120 ◽

1998 ◽

Vol 78 (4) ◽

pp. 719-722

Author(s):

A. D. Iwaasa ◽

K. A. Beauchemin ◽

S. N. Acharya ◽

J. G. Buchanan-Smith

Keyword(s):

Cell Wall ◽

Medicago Sativa ◽

Key Words ◽

Chemical Constituents ◽

Stem Segment ◽

Shearing Force ◽

Medicago Sativa L ◽

Genotype Clustering ◽

Force Characteristics

Shearing force of alfalfa (Medicago sativa L.) stems was measured to evaluate genotype-by-year interactions. Based on mean shearing force for each stem segment and genotype clustering criteria, several genotypes had similarly shearing forces among years. Therefore, selecting genotypes with desirable shearing force characteristics to improve digestibility or intake potential of forages may be possible. Key words: Genotype, environment, shearing force, cell wall chemical constituents

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The effects of long-term cadmium exposure on the growth and survival of juvenile bull trout (Salvelinus confluentus)

Aquatic Toxicology ◽

10.1016/s0166-445x(01)00233-8 ◽

2002 ◽

Vol 58 (3-4) ◽

pp. 165-174 ◽

Cited By ~ 52

Author(s):

J.A Hansen ◽

P.G Welsh ◽

J Lipton ◽

M.J Suedkamp

Keyword(s):

Cadmium Exposure ◽

Bull Trout ◽

Salvelinus Confluentus ◽

Growth And Survival

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Non-Occupational Cadmium Exposure is Emerging as a Major Cause of Cancer, Vascular Disorders, and Other Pathologies - A Long-term Controlled Trial of Supplementation with High-Dose Zinc, a Cadmium Antagonist, is Needed

Journal of Preventive Medicine ◽

10.21767/2572-5483.100001 ◽

2016 ◽

Vol 01 (01) ◽

Cited By ~ 1

Author(s):

Mark McCarty F ◽

James DiNicolantonio J

Keyword(s):

Controlled Trial ◽

Cadmium Exposure ◽

High Dose ◽

Vascular Disorders

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Cell-wall polysaccharides and glycoproteins of parenchymatous tissues of runner bean (Phaseolus coccineus)

Biochemical Journal ◽

10.1042/bj2690393 ◽

1990 ◽

Vol 269 (2) ◽

pp. 393-402 ◽

Cited By ~ 34

Author(s):

P Ryden ◽

R R Selvendran

Keyword(s):

Cell Wall ◽

Cell Walls ◽

Anion Exchange Chromatography ◽

Structural Features ◽

Good Evidence ◽

Exchange Chromatography ◽

Cell Wall Polysaccharides ◽

Pectic Polysaccharides ◽

Runner Bean ◽

Cellulose Residue

1. Polymers were solubilized from the cell walls of parenchyma from mature runner-bean pods with minimum degradation by successive extractions with cyclohexane-trans-1,2-diamine-NNN′N′-tetra-acetate (CDTA), Na2CO3 and KOH to leave the alpha-cellulose residue, which contained cross-linked pectic polysaccharides and Hyp-rich glycoproteins. These were solubilized with chlorite/acetic acid and cellulase. The polymers were fractionated by anion-exchange chromatography, and fractions were subjected to methylation analysis. 2. The pectic polysaccharides differed in their ease of extraction, and a small proportion were highly cross-linked. The bulk of the pectic polysaccharides solubilized by CDTA and Na2CO3 were less branched than those solubilized by KOH. There was good evidence that most of the pectic polysaccharides were not degraded during extraction. 3. The protein-containing fractions included Hyp-rich and Hyp-poor glycoproteins associated with easily extractable pectic polysaccharides, Hyp-rich glycoproteins solubilized with 4M-KOH+borate, the bulk of which were not associated with pectic polysaccharides, and highly cross-linked Hyp-rich glycoproteins. 4. Isodityrosine was not detected, suggesting that it does not have a (major) cross-linking role in these walls. Instead, it is suggested that phenolics, presumably linked to C-5 of 3,5-linked Araf residues of Hyp-rich glycoproteins, serve to cross-link some of the polymers. 5. There were two main types of xyloglucan, with different degrees of branching. The bulk of the less branched xyloglucans were solubilized by more-concentrated alkali. The anomeric configurations of the sugars in one of the highly branched xyloglucans were determined by 13C-n.m.r. spectroscopy. 6. The structural features of the cell-wall polymers and complexes are discussed in relation to the structure of the cell walls of parenchyma tissues.

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Aluminum toxicity in alfalfa ( Medicago sativa ) is alleviated by exogenous foliar IAA inducing reduction of Al accumulation in cell wall

Environmental and Experimental Botany ◽

10.1016/j.envexpbot.2017.03.018 ◽

2017 ◽

Vol 139 ◽

pp. 1-13 ◽

Cited By ~ 19

Author(s):

Shengyin Wang ◽

Shili Yuan ◽

Liantai Su ◽

Aimin Lv ◽

Peng Zhou ◽

...

Keyword(s):

Cell Wall ◽

Medicago Sativa ◽

Aluminum Toxicity

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Modification of Cell Wall Polysaccharides during Drying Process Affects Texture Properties of Apple Chips

Journal of Food Quality ◽

10.1155/2018/4510242 ◽

2018 ◽

Vol 2018 ◽

pp. 1-11 ◽

Cited By ~ 5

Author(s):

Min Xiao ◽

Jianyong Yi ◽

Jinfeng Bi ◽

Yuanyuan Zhao ◽

Jian Peng ◽

...

Keyword(s):

Cell Wall ◽

Structural Characteristics ◽

Volume Ratio ◽

Short Wave ◽

Cell Wall Polysaccharide ◽

Cell Wall Polysaccharides ◽

Rehydration Ratio ◽

Pectic Polysaccharides ◽

Texture Properties ◽

Instant Controlled Pressure Drop

The influences of hot air drying (AD), medium- and short-wave infrared drying (IR), instant controlled pressure drop drying (DIC), and vacuum freeze drying (FD) on cell wall polysaccharide modification were studied, and the relationship between the modifications and texture properties was analyzed. The results showed that the DIC treated apple chips exhibited the highest crispness (92) and excellent honeycomb-like structure among all the dried samples, whereas the FD dried apple chips had low crispness (10), the minimum hardness (17.4 N), and the highest volume ratio (0.76) and rehydration ratio (7.55). Remarkable decreases in the contents of total galacturonic acid and the amounts of water extractable pectin (WEP) were found in all the dried apple chips as compared with the fresh materials. The highest retention of WEP fraction (102.7 mg/g AIR) was observed in the FD dried apple chips, which may lead to a low structural rigidity and may be partially responsible for the lower hardness of the FD apple chips. In addition, the crispness of the apple chips obtained by DIC treatment, as well as AD and IR at 90°C, was higher than that of the samples obtained from the other drying processes, which might be due to the severe degradation of pectic polysaccharides, considering the results of the amounts of pectic fractions, the molar mass distribution, and concentrations of the WEP fractions. Overall, the data suggested that the modifications of pectic polysaccharides of apple chips, including the amount of the pectic fractions and their structural characteristics and the extent of degradation, significantly affect the texture of apple chips.

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