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1.
Iron Enhances Aluminum-induced Leaf Necrosis and Plant Growth Inhibition in Eucalyptus camaldulensis
The combined effects of excess Fe and Al on Eucalyptus camaldulensis Dehnh. were studied by investigating time course and visible symptoms of leaf necrosis, plant biomass, the status of some
antioxidants and pigments and nutrient concentrations. Seedlings were grown hydroponically in nutrient solutions containing
0 or 500 μM AlCl3, each with a FeSO4 range of 1, 12 and 120 μM at pH 4.2. Leaf necrosis and plant growth inhibition were induced by Al and enhanced by the increase in Fe concentration.
The process from the first appearance of necrotic spots to leaf death (shedding) of a leaf proceeded from a few days to about
20 days after the leaf had fully expanded. Either 120 μM Fe without Al or Al reduced plant growth to a similar extent but 120 μM Fe without Al did not cause leaf necrosis. In leaves, excess Fe (12 and 120 μM) without Al reduced concentration of ASC and GSH, while concentration of Fe, DHA and GSSG and DHA:ASC and GSSG:GSH ratios
tended to increase with the increase in Fe concentration in treatment solution with or without Al. At 1 μM Fe, Al increased concentration of DHA and DHA:ASC and GSSG:GSH ratios. Catalase activity in leaves reduced with the increase
in leaf Al concentration. At 1 μM Fe, Al greatly reduced concentrations of Fe and chlorophylls in leaves but increase two times Fe concentration in stems.
These suggest that the enhancement effects of Fe on Al-induced leaf necrosis and plant growth inhibition can be discussed
in context of the excess Fe itself weakens antioxidant capability of ASC–GSH cycle in leaves and greatly reduces plant growth;
and the increase in Fe accumulation in stems is involved in Al-induced leaf chlorosis. 相似文献
2.
Burnatowska-Hledin Maria Ebner Karl V. Mayor Gilbert H. 《Biological trace element research》1986,10(3):235-242
This study examines the effect on mitochondrial respiration and permeability of in vivo and in vitro aluminium (Al) exposure.
Rats were treated intraperitoneally with AlCl3 to achieve serum and liver Al concentrations comparable to those seen in Al-related disorders. Mitochondria isolated from
Al-treated rats had higher (p<0.01) Al concentration, lower (p<0.05) state 3 respiration, respiratory control (RCR), and ADP/O ratio (succinate substrate), and greater passive swelling
in 100 mM KCl or 200 mM NH4NO3 than controls. The in vitro addition of Al (0–180 μM) to mitochondria from normal rats also decreased (p<0.01) state 3 respiration, RCR, and ADP/O and stimulated passive swelling in KCl and NH4NO3 at 42–180 μM Al. These studies show that Al depresses mitochondrial energy metabolism and increases membrane permeability. The toxicity
associated with Al may be related to its effect on mitochondria. 相似文献
3.
Aluminum effects on the morphological development of soybean (Glycine max (L.) Merr.) were characterized in greenhouse and growth chamber experiments. An Al-sensitive cultivar, ‘Ransom’, was grown
in an acid soil (Aeric Paleudult) adjusted to 3 levels of exchangeable Al. Lateral shoot development at the nodes of the main
stem was extensive in the limed soil containing 0.06 cmol(+) Alkg−1. However, lateral shoot length and weight were severely inhibited in the unlimed soil containing 2.19 cmol(+) Alkg−1, and in the unlimed soil amended to 2.63 cmol(+) Alkg−1 with AlCl3. This inhibition by the high Al/low pH condition was reversed by the exogenous application of a synthetic cytokinin 6-benzylaminopurine
(BA). The daily application of 20 μg mL−1 BA applied locally to the lateral meristems of plants grown in the unlimed soil stimulated lateral shoot growth substantially,
such that it was either comparable to or greater than that observed in the limed treatment without BA. Accumulation of K,
Ca, and Mg in lateral shoot branches was also stimulated by the local application of BA. The inhibitory effects of Al on lateral
shoot development were confirmed in solution culture. In addition, differential sensitivity to Al was evident among the primary
root, first order lateral roots, and second order lateral roots. The length of the primary root was only slightly decreased
by increasing concentrations of Al up to 30 μM. In contrast, the length of basipetally located first order lateral roots was restricted to greater extent; up to 50% by
30 μM Al. Second order lateral lengths were inhibited even more severely; up to 86% by 30 μM Al. Substantial evidence in the literature indicates that the root apex is a major site for the biosynthesis of cytokinin
that is supplied to shoots, and cellular function and development in this region of the root are impaired during Al toxic
conditions. This suggests that one mode of action by which Al may affect shoot growth is by inhibiting the synthesis and subsequent
translocation of cytokinin to the meristematic regions of the shoot. The present observation of a reversal of Al-inhibited
lateral shoot development by exogenously applied cytokinin supports this hypothesis. However, the inability of applied cytokinin
to counter the restriction imposed by Al on total shoot dry matter production implies the impairment by Al toxicity of other
root functions, such as ion and water transport, also played an important role in altering shoot morphology. 相似文献
4.
Henry D. Schreiber Andrew H. Jones Corinne M. Lariviere Kelly M. Mayhew Judith B. Cain 《Biometals》2011,24(6):1005-1015
Red, purple, and blue sepals on selected cultivars of Hydrangea macrophylla were analyzed for their aluminum content. This content was determined to be a function of the sepal color with red sepals
possessing 0–10 μg Al/g fresh sepal, purple sepals having 10–40 μg Al/g fresh sepal, and blue sepals containing greater than
40 μg Al/g fresh sepal. Accordingly, the threshold aluminum content needed to change H. macrophylla sepals from red to blue was about 40 μg Al/g fresh sepal. Higher aluminum concentrations were incorporated into the sepals,
but this additional aluminum did not affect the intensity or hue of the blue color. These observations agreed with a chemical
model proposing that the concentration of the blue Al3+-anthocyanin complex reached a maximum when a sufficient excess of aluminum was present. In addition, the visible absorbance
spectra of harvested red, purple, and blue sepals were duplicated by Al3+ and anthocyanin (delphinidin-3-glucoside) mixtures in this model chemical system. 相似文献
5.
Aluminum (Al) in the rhizosphere adversely affects plant nutrition and growth. Although many conifer species, and pitch pine
(Pinus rigida) in particular, have evolved on acidic soils where soluble Al is often high, controlled environment studies often indicate
that Al interferes with seedling growth and nutrient relations. Under normal field conditions, conifer roots grow in a symbiotic
relationship with ectomycorrhizal fungi, and this association may modulate the effects of Al on root physiology. To investigate
the influence of mycorrhizal infection on Al toxicity, pitch pine seedlings were grown with or without the ectomycorrhizal
symbiont Pisolithus tinctorius and were exposed to low levels of Al in sand culture. Aluminum at 50 μM reduced nonmycorrhizal seedling growth and increased foliar Al concentrations, but did not alter photosynthetic gas exchange
or other aspects of seedling nutrition. Nonmycorrhizal seedlings exposed to 200 μM Al exhibited decreased growth, increased transpiration rates, decreased water use efficiency, increased foliar Al and Na
levels, and reduced foliar P concentrations. Seedlings inoculated with P. tinctorius exhibited unaltered growth, physiological function, and ionic relations when exposed to Al. The fungal symbiont evidently
modulated ionic relations in the rhizosphere, reducing Al-P precipitation reactions, Al uptake, and subsequent root and shoot
tissue Al exposure. 相似文献
6.
The present study was conducted to investigate the effects of enhanced Ca supply on Al toxicity in relation to cell wall properties
in two wheat (Triticum aestivum L.) cultivars differing in Al resistance. Seedlings of Al-tolerant Inia66 and Al-sensitive Kalyansona cultivars were grown
in complete nutrient solutions for 4 days then subjected to treatment solutions containing Al (0, 50 μM) and Ca (500, 2500 μM)
at pH 4.5 for 24 h. Root elongation was affected greatly by Al treatment in the Al-sensitive cultivar and a significant improvement
in root growth was observed with enhanced Ca supply during Al stress. Pectin and hemicellulose contents in the root cell walls
increased with Al stress, and this increase was more conspicuous in the Al-sensitive cultivar. The molecular mass of hemicellulosic
polysaccharides increased with Al treatment in the Al-sensitive cultivar and decreased with enhanced Ca supply. The increase
in the molecular mass of hemicellulosic polysaccharides was attributed to increased content of glucose, arabinose and xylose
in neutral sugars. Enhanced Ca supply slightly decreased the content of these components with Al stress. Aluminum treatment
increased the contents of ferulic and p-coumaric acid, especially in the Al-sensitive cultivar, by increasing peroxidase (POD, EC 1.11.1.7) and phenylalanine ammonia
lyase (PAL, EC 4.3.1.5) activity, whereas enhanced Ca supply during Al stress decreased the content of these components by
decreasing POD and PAL activity. These results suggest that the increased molecular mass of hemicellulosic polysaccharides
and phenolic compounds in the Al-sensitive cultivar with Al stress might have inhibited root elongation associated with cell
wall stiffening related to cross-linking among cell-wall polymers and lignin. Enhanced Ca supply might maintain the normal
synthesis of these materials even with Al stress. 相似文献
7.
Horiguchi T Ohta Y Nishikawa T Shiraishi F Shiraishi H Morita M 《Cell biology and toxicology》2008,24(6):553-562
To clarify how tributyltin (TBT) and triphenyltin (TPT) interact with the retinoid X receptor (RXR) to induce growth of male
sex organs in female gastropods, we treated female rock shells (Thais clavigera) with three different concentrations (0.1, 1, or 5 μg/g wet wt) of 9-cis-retinoic acid (9CRA) or with a single concentration (1 μg/g wet wt) of TBT, TPT, or fetal bovine serum (as a control). The
effects of each treatment were measured as the incidence of imposex, the length of the penis-like structure, and the vas deferens
sequence (VDS) index. 9CRA induced imposex in a dose-dependent manner; imposex incidence was significantly higher in the rock
shells that received 1 (P < 0.05) or 5 μg (P < 0.001) 9CRA than in the controls. After 1 month, the rock shells treated with 5 μg 9CRA exhibited substantial growth of
the penis-like structure that was not as evident in the other treated shells. The length of the structure differed between
the 0.1- and 5-μg 9CRA treatment groups (P < 0.05) but not between the 1- and 5-μg 9CRA treatment groups (P > 0.05). Compared with the control, the VDS index increased significantly in the 1- (P < 0.05) and 5-μg (P < 0.001) 9CRA groups. The penis-like structures behind the right tentacle in female rock shells treated with 5 μg 9CRA were
essentially the same as the penises and vasa deferentia of normal males and of TBT-treated or TPT-treated imposexed females.
These results further support the hypothesis that imposex in gastropods could be mediated by RXR. 相似文献
8.
Effect of triethylenepentaminehexaacetic acid on the renal damage in cadmium-treated Syrian hamsters 总被引:2,自引:0,他引:2
Toshiaki Shibasaki Q. -Y. Xu Iwao Ohno Fumio Ishimoto Osamu Sakai 《Biological trace element research》1995,50(2):157-165
Cadmium (Cd)-induced nephropathy was treated by triethylene-pentaminehexaacetic acid (TTHA) in male Syrian hamsters. Hamsters
injected three times a week with 3 mg/kg body wt CdCl2 showed proteinuria, urinaryN-acetyl-β-d-inglucosaminidase (NAG), and fractional excretion of sodium (FENa) when compared to saline-injected control. Cd-treated hamsters
injected ip with TTHA 10 mg/kg body wt five times a week showed reduction of renal damage, including reductions in urinary
protein (from 6.7±2.2 to 4.3±0.5 mg/d) and NAG (0.17±0.06 to 0.04±0.02 U/d). Urinary excretion of Cd was significantly increased
(from 87±51.3 to 3052±1485 mg/L) by TTHA administration. Cd concentration in renal cortical tissue was slightly reduced (26.4±3.0
to 21.8±2.7 mg/g. protein). Excretion of malondialdehyde (MDA) was increased only in Cd-injected hamsters (to 2.1±1.6 nM/L), and elevated MDA in renal cortical tissue was not reduced by the administration of TTHA (1041±105 vs 1104±358 nM/g protein). Glutathione (GSH) concentration in the renal cortex was significantly elevated after Cd administration and further
increased after TTHA administration (5.5±2.1 to 9.8±2.0 μg/50 mg protein). There were no marked effects on creatinine clearance
(Ccr) and hematocrit. Moreover, renal morphological changes were improved significantly by treatment with TTHA.
We demonstrated the efficacy of TTHA in the treatment of Cd-induced nephropathy in hamsters. Although the precise mechanism
of the TTHA effects on Cd-induced nephropathy has not been elucidated, it might involve GSH reducing the elevated MDA concentration
in renal tissue. 相似文献
9.
Hawkes WC Richter BD Alkan Z Souza EC Derricote M Mackey BE Bonnel EL 《Biological trace element research》2008,122(2):107-121
The essential nutrient selenium is required in microgram amounts [recommended dietary allowance (RDA) = 55 μg/day, 699 nmol/day]
and has a narrow margin of safety (upper tolerable intake limit = 400 μg/day, 5 μmol/day). We conducted a randomized placebo-controlled
study of high-selenium yeast, the form used in most supplements (300 μg/day, 3.8 μmol/day), administered to 42 free-living
healthy men for 48 weeks. Dietary intakes of selenium, macronutrients, and micronutrients were not different between groups
and did not change during the study. Supplementation more than doubled urinary selenium excretion from 69 to 160 μg/day (876
to 2,032 nmol/day). Urinary excretion was correlated with recent selenium intake estimated from 3-day diet records: urinary
selenium excretion = 42 μg/day (533 nmol/day) + 0.132 × dietary selenium intake, p < 0.001. Dietary selenium intake was not significantly correlated with the other indicators of selenium status, presumably
because urinary selenium excretion reflected recent intake, and tissue selenium was homeostatically controlled. After 48 weeks
of supplementation, plasma selenium was increased 60% from 142 to 228 μg/l (1.8 to 2.9 μmol/l), and erythrocyte selenium was
approximately doubled from 261 to 524 μg/l (3.3 to 6.6 μmol/l). Selenium concentrations increased more modestly in hair (56%)
and platelets (42%). Platelets were the only blood component in which glutathione peroxidase activity was significantly related
to selenium content. Selenium levels decreased rapidly after the end of supplementation, and there were no significant differences
in selenium status indicators between groups by week 96. The absorption, distribution, and excretion of selenium from high-Se
yeast were similar to selenium in foods. 相似文献
10.
Wayne Chris Hawkes Calvin C. Willhite Kimberly A. Craig Stanley T. Omaye Douglas N. Cox Wai Nang Choy Andrew G. Hendrickx 《Biological trace element research》1992,35(3):281-297
Forty pregnant long-tailed macaques were treated daily for 30 d with 0, 25, 150 or 300 μg selenium as L-selenomethionine/kg
body weight. Erythrocyte and plasma selenium and glutathione peroxidase specific activities, hair and fecal selenium, and
urinary selenium excretion were increased by and were linearly related to L-selenomethionine dose. Hair selenium was most
sensitive to L-selenomethionine dose, with an 84-fold increase in the 300 μg selenium/(kg-d) group relative to controls (r=0.917). Daily urinary selenium excretion (80-fold,r=0.958), plasma selenium (22-fold,r=0.885), erythrocyte selenium (24-fold,r=0.920), and fecal selenium (18-fold,r=0.911) also responded strongly to L-selenomethionine. Erythrocyte and plasma glutathione peroxidase specific activities increased
154% and 69% over controls, respectively. Toxicity was associated with erythrocyte selenium >2.3 μg/mL, plasma selenium >2.8
μg/mL, and hair selenium >27 μg/g. Plasma, erythrocyte, and hair selenium concentrations may be useful for monitoring and
preventing the toxicity of L-selenomethionine administered to humans in cancer chemoprevention trials. 相似文献
11.
M. Wilhelm J. Hoelzer K. Luebbers G. Stoehr C. Ohmann 《Journal of trace elements in medicine and biology》2001,14(4):223-227
Aluminum (Al) is a well known contaminant of intravenous solutions. The aim of the present study was the estimation of the aluminum load in patients of an intensive care unit (ICU). 15 patients with normal renal function took part. The study period was 15 days. Al was measured in serum, 24h-urine and 132 samples of parenterals. Daily Al doses were recorded. Al balance was calculated on the basis of the iatrogenic Al dose and renal Al excretion. Al analysis was performed by graphite furnace atomic absorption spectrometry (AAS) with Zeeman background correction under careful quality control. Solutions with Al levels >100 μg/l were: calcium salts, additives for parenteral nutrition solutions, antibiotics, acetylcysteine, triflupromazine, catecholamines and colloids. The Al content of solutions for parenteral nutrition ranged from 4.3 to 69 μg/l. Al doses amounted to 46 – 456 (median 119) μg/d, equivalent to 0.7 to 6.5 (median 1.7) μg/kg b.w. Renal Al excretion ranged from 10.5 to 723.1 μg/d (median 53 μg/d). These amounts partly exceeded the maximal dose (2 μg/kg b.w. per day), recommended by ASPEN/ASCN. Despite of the highly elevated renal Al excretion the median serum concentration of Al was only moderately increased (6.1 μg/l; range: <1.5 to 23.6 μg/l). However, calculations on the basis of the iatrogenic Al dose and renal Al excretion resulted in a net Al uptake (median) of 61 μg/d (maximum: 291 μg/d). Al amounts of this magnitude must be considered potentially harmful in ICU patients, especially with impaired renal function. Parenteral therapy resulted in a considerable Al dose with a positive Al balance in ICU patients. Threshold values for Al contamination of parenterally administered drugs and solutions should be established. 相似文献
12.
Hubert F. Loyke 《Biological trace element research》1992,33(1-3):129-133
With reports of either no change or reduction of blood pressure, the relationship between selenium and blood pressure has
not been clear. Normal Se values are not available for the Sprague Dawley (SD) rat or in the young and adult rat with various
models of experimental hypertension. This study measured serum Se levels in the young and adult normotensive (NT), Grollman
renal hypertensive (RH), and Okamoto-Aoki spontaneous hypertensive rats (SHR). The young animals have statistically significant
(P<0.001) lower Se values as measured by the fluorometric method than those found at adulthood. Selenium levels were found to
be altered in the adult SHR animals when compared with the RH and NT animals. The serum Se value for the normotensive SD rat
was found to be 65.0±3.5 μg/dL, and for the two experimental models, 63.7±4.6 μg/dL for the RH, whereas the SHR level was
elevated to 75.04±4.8 μg/dL (P<0.001). Elevated serum Se values in the adult SHR animals suggests an altered metabolism in SHR animals. 相似文献
13.
Aluminum (Al) inhibits root growth in acidic soil, but the site of action of Al remains unclear. We investigated whether the
rate of Al accumulation correlates to Al-indeced rapid root growth inhibition in rice seedlings (Oryza sativa L. cv. Youngnam). Growth of roots was significantly inhibited by 100 μM AICI3, as early as 1 h after the treatment. The inhibition of root growth was strongly dependent on Al concentration (l50 = 20 (μM) and Al-exposure time (l50 = 23 min at 25 μM Al) in a solution of 10 mM KCI and 1 mM CaCl2 buffered by 10 mM Mes/KOH (pH 4.5). Using ICPES, massive uptake of Al by roots was observed even at 15 min treatment of 25
μM Al. The kinetics of Al uptake by the roots closely corresponded to the inhibitory effects of Al on root growth. When the
roots of seedlings were exposed to 50 (μM Al for 1 h, then sectioned and stained with hematoxylin, all cell types of the roots
showed the presence of Al in the cytoplasm. These results indicate that Al was rapidly taken up into the root cells and thereby
reduced root growth. 相似文献
14.
Dennis B. Lazof Magaly Rincón Thomas W. Rufty Charles T. Mackown Thomas E. Carter 《Plant and Soil》1994,164(2):291-297
A study was conducted to examine aluminum (Al) exclusion by roots of two differentially tolerant soybean (Glycine max L. Merr.) lines, Pl-416937 (Al-tolerant) and Essex (Al-sensitive). Following exposure to 80μM Al for up to 2 h, roots were rinsed with a 10 mM potassium citrate solution and rapidly dissected to allow estimation of intracellular Al accumulation in morphologically
distinct root regions. Using 10 min exposures to 300μM
15NO3
− and dissection, accompanying effects on NO3
− uptake were measured. With Al exposures of 20 min or 2 h, there was greater Al accumulation in all root regions of Essex
than in those of Pl-416937. The genotypic difference in Al accumulation was particularly apparent at the root apex, both in
the tip and in the adjacent root cap and mucilage. Exposure of roots to Al inhibited the uptake of 15NO3
− to a similar extent in all root regions. The results are consistent with Al exclusion from cells in the root apical region
being an important mechanism of Al tolerance. 相似文献
15.
Two groups of 16 rats each were fed the same diet with 12.9 ppm Zn. Nine days after each animal was injected with65Zn for assessing fecal zinc of endogenous origin, zinc intake and excretion were determined for a six-day period at the age
of about five (group I) and nine (II) weeks. At mean growth rates of 5.1 and 5.2 g/day, food consumption per gram of gain
was 2.01 g in group I vs 2.86 g in II. Overall, zinc retention amounted to 21 vs 25 μg Zn/g of gain. Apparent absorption averaged
92 vs 74% of Zn intake (132 vs 189 μg/day), while true absorption averaged 98 vs 92%. It was concluded that endogenous fecal
zinc excretion was limited to the indispensable loss (F
em) in group I (7 μg/day), while it exceeded this minimum loss in group II (33 μg/day). True retention, which reflected total
zinc utilization (true absorption times metabolic efficiency), was derived from apparent absorption plusF
em (11 μg/day for group II according to the greater metabolic body size of the rats). It averaged 98% of Zn intake in group
I vs 80% in group II. The mean metabolic efficiency was 100% vs 87%. The conclusion was that these marked differences between
age groups in utilizing the dietary zinc reflected the efficient homeostatic adjustments in absorption and endogenous excretion
of zinc to the respective zinc supply status. 相似文献
16.
Eighteen metals were estimated in the scalp hair samples from cancer patients (n = 111) and normal donors (n = 113). Nitric acid–perchloric acid wet digestion procedure was used for the quantification of the selected metals by flame
atomic absorption spectrophotometry. In the scalp hair of cancer patients, highest average levels were found for Ca (861 μg/g),
followed by Na (672 μg/g), Zn (411 μg/g), Mg (348 μg/g), Fe (154 μg/g), Sr (129 μg/g), and K (116 μg/g), whereas in comparison,
the dominant metals in the scalp hair of normal donors were Ca (568 μg/g), Zn (177 μg/g), Mg (154 μg/g), Fe (110 μg/g), and
Na (103 μg/g). The concentrations of Ca, Cd, Co, Cr, Fe, K, Mg, Mn, Na, Ni, Pb, Sb, Sr, and Zn were notably higher in the
hair of cancer patients as compared with normal donors, which may lead to a number of physiological disorders. Strong positive
correlations were found in Mn–Pb (0.83), Cd–Cr (0.82), Cd–Li (0.57), Fe–Pb (0.56), and Fe–Mn (0.55) in the hair of cancer
patients whereas Na–Cd, Li–Cr, Li–Co, Co–Cd, Li–Cd, Na–Co, Na–Li, Ca–Mg and Na–Cr exhibited strong relationships (r > 0.50) in the hair of normal donors. Principal Component Analysis (PCA) of the data revealed seven PCs, both for cancer
patients and normal donors, but with significantly different loadings. Cluster Analysis (CA) was also used to support the
PCA results. The study evidenced significantly different pattern of metal distribution in the hair of cancer patients in comparison
with normal donors. The role of trace metals in carcinogenesis was also discussed. 相似文献
17.
Ultrastructure and elemental composition of the eggshell of Reeve’s pheasant ( Syrmaticus reevesii )
Chang Chongyan Zhang Zhengwan Chen Xiaoduan Liu Jinying Sun Quanhui 《Frontiers of Biology in China》2007,2(3):340-344
The eggshell of Reeve’s pheasant (Syrmaticus reevesii) collected from the Dongzhai National Nature Reserve in Henan Province, China was studied. By using scanning electron microscopy
and inductively coupled plasma (ICP) spectrometry, the ultrastructure and elemental composition of the eggshell was determined.
The study showed that the average thickness of the surface layer of crystals, the palisade and cone layer, and the eggshell
membrane were 20.8, 220.8 and 62.5 μm, respectively, accounting for 6.8%, 72.6% and 20.6% of the total thickness of the eggshell.
There were many vesicular holes in the palisade layer with an average diameter of 0.32 ± 0.08 μm (n = 30). The function of these holes might be significant to air exchange. The shape of the eggshell pore on the surface layer
of crystals is round or elliptical. The fracture surface of the pore is funnel-shaped. Some granules filled the upper part
of the eggshell pores. The content of 21 elements in the eggshell of wild and captive Reeve’s pheasants was compared and presented.
It indicated that among the elements that made up the eggshell of the wild pheasant, the content of Ca, Mg, P and S was much
higher, ω > 1 mg/g, with ω (Ca) being higher than 40% of the eggshell. The contents of Na, Si, Sr, K and Al were ω = 0.1–1 mg/g, while Fe, Zn, Pb, Mn, Cu, V and Ti had lower concentrations (ω = 1–100 μg/g). The ω of Ni, Cr, Co, Se, Cd were lower than 1 μg/g. The elemental composition in the eggshell of the captive Reeve’s pheasant kept
in the Dongzhai National Natural Reserve was significantly different from that of the wild species, with a difference of over
20% on S, Cu, Fe, Al, Mn, Si, Sr, Se and Cr. The lower intake of Fe, Mn, Si and Sr on the one hand and the higher intake of
S, Cu, Al and Cr on the other hand might be responsible for the low fertility of captive Reeve’s pheasants in the Dongzhai
National Nature Reserve. In order to ensure that the pheasants are receiving the proper amount of nutrition and to improve
their breeding success, the amount of certain elements in the food should be adjusted.
Translated from Journal of Beijing Normal University (Natural Science), 2006, 42(1): 78–82 [译自: 北京师范大学学报 (自然科学版)] 相似文献
18.
Vegetable soybeam germplasm was screened for its tolerance to 0, 50 and 100 μM Al in solution culture. Plants were inoculated with prescreened acid-Al tolerantBradyrhizobium japonicum strain USDA 110 and a localRhizobium isolate SM867. Aluminum concentrations of 0, 50, and 100 μM affected the root lengths of all germplasm lines in the first few weeks of their growth. At 100 μM, the plants had severely stunted roots throughout the growing period of 35 days, but at 50 μM the initial stunting of the roots was overcome after the third week of growth, and there were no significant differences
between the root lengths of these plants and of the controls. The appearance of the first nodule was delayed for 2–3 and 4–5
days at 50 μM and 100 μM Al, respectively. There was a significant reduction in nodule numbers and acetylene reduction activity (ARA) at 100 μM Al. At 50 μM Al, even though the number of nodules was decreased significantly, nodules were larger in size, so there was no significant
reduction in nodule fresh weight and ARA. No significant differences in nitrogen fixing abilities of the soybean lines were
observed between the twoRhizobium strains. Germplasm line Kahala showed the greatest tolerance to 50 μM Al, and Kahala, Kim and Wolverine tolerated 100 μM Al better than other germplasm lines. 相似文献
19.
Fusarium toxins are secondary metabolites produced byfungi of these genera in many commodities under certain conditions. A study was carried out to investigate the co-occurrence of
zearalenone (ZEN), deoxynivalenol (DON) and fumonisins (FB1 and FB2) in 52 samples of mixed-feed for poultry contaminated withFusarium verticillioides. The zearalenone and deoxynivalenol were checked using immunoaffinity column and the extraction of fumonisin was performed
by strong anion exchange (SAX) solid phase column. Detection and quantification were determined by high performance liquid
chromatography (HPLC). The limit of detection was 5 μg/kg for ZEN, 100 μg/kg for DON and 50 and 100 μg/kg for FB1 and FB2 respectively.Fusarium toxins were detected in 20 samples. Sixteen samples were positive for ZEN (30.7%) presenting levels that ranged from 7.4
μg/kg to 61.4 μg/kg (mean=27.0 μg/kg). 13.5% of the samples presented contaminations of DON, with levels ranging from 100.0
μg/kg to 253 μg/kg (mean=l18.07 μg/kg). FB1 was detected in 19.2% of samples, with levels ranging from 50.0 μg/kg to 110.0 μg/kg (mean=73.6 μg/kg). FB2 was not detected
in any sample. In positive samples simultaneously contamination with two or three mycotoxins were detected in 9 of them (17.3%). 相似文献
20.
Summary In anaesthetized adult female rats, the influence of epidermal growth factor (EGF) on renal amino acid handling was investigated in glutamine, arginine (both 50 mg/100 g b. wt. per hour), or alanine (90 mg/ 100 g b. wt. per hour) loaded animals. Continuous infusions of the three amino acids were followed by an increase in the fractional excretion (FE) of the administered amino acids as well as of the other endogenous amino acids. Under load conditions (alanine, arginine or glutamine), EGF pretreatment (8g/100g b. wt. subcutaneously for 8 days, twice daily 8 a.m. and 4 p.m.) was followed by a stimulation of renal amino acid reabsorption. The increase in the fractional excretion of the administered amino acids was significantly lower than in non-EGF-treated rats. These changes in amino acid transport were connected with a significant reduction of GFR after EGF pretreatment (0.96 ± 0.10 vs. 0.62 ± 0.07 ml/min X 100 g b. wt.) and a distinct increase in sodium excretion (2.98 ± 0.55 vs. 4.97 ± 0.71val/100 g b. wt. X 20 min). After loading with p-aminohippurate (PAH; 200mg/100g b. wt.), PAH excretion in EGF rats was increased by about 20%, whereas urinary protein excretion was lower in EGF pretreated rats (control: 0.45 ± 0.04 vs. EGF: 0.18 ± 0.03 mg/ 100 g b. wt. X 20 min). The PAH load reduced amino acid reabsorption as a sign of overloading of renal tubular transport capacity, but in EGF pretreated animals the amino acid excretion was only slightly increased under these conditions. Furthermore, EGF pretreatment depressed normal kidney weight gain significantly (874 ± 18 vs. 775 ± 32mg/100g b. wt.). EGF can improve the renal tubular transport capacity, but, compared to well-known stimulators of renal transport like dexamethasone or tri-iodothyronine, its effect is only of a moderate degree. 相似文献