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1.
Eleven horizons of acidic soils in mid-Wales developed from Lower Palaeozoic sedimentary rocks were examined. Selective extraction of Al and Si provided evidence against the occurrence of significant quantities of poorly ordered Al-silicates. Fe0 was weakly correlated with Al0 , but very closely correlated with Al0 minus Al extracted by cold 5% Na2 CO3 , implying that poorly ordered Al occurs in part as a substituent in Fe oxide and in part in a form unassociated with Fe oxide. Support for this was obtained by analysis of oxide fractions concentrated from aqueous suspensions by sequential ultracentrifugation and through the examination of synthetic Al-substituted Fe oxides. Fe oxide containing Al substituted at an almost constant level was the dominant constituent of the poorly ordered fraction in four of the five Bs horizons examined. The occurrence of Al in this form is an important mechanism by which Al is retained in aerobic but highly acidic Bs horizons. 相似文献
2.
Xiaoyu LI Jiaju LIU Yuting ZHANG Jixiang LIN Chunsheng MU 《Soil Science and Plant Nutrition》2009,55(5):680-684
Effects of salt (NaCl : Na2 SO4 ) and alkali (NaHCO3 : Na2 CO3 ) stresses on the contents of inorganic ions and organic solutes in wheat shoots were compared to explore the physiological responses and adaptive strategies of wheat to these stresses. Wheat significantly accumulated Na+ and simultaneously accumulated Cl− , soluble sugars and proline to maintain osmotic and ionic balance under salt stress. Compared with salt stress, the high pH from alkali stress enhanced Na+ accumulation and affected the absorption of inorganic anions. To maintain ionic and osmotic balance, wheat accumulated organic acids, soluble sugars and proline. The accumulation of Cl− and organic acids was the main difference in the physiological responses and adaptive mechanisms to salt and alkali stresses, respectively. 相似文献
3.
Keitaro Tanoi Junko Hojo Kazutoshi Suzuki Yoshitake Hayashi Hiroki Nishiyama Tomoko M. Nakanishi 《Soil Science and Plant Nutrition》2005,51(5):715-717
We investigate the effect of Al on K+ uptake by rice roots. Potassium-38 (38 K), a positron emitting nuclide (the half-life: 7.61 min), was used to trace K+ behavior. When a rice root was treated with 10μM Al for 24 h, the uptake of 38 K in the root was increased in the range of 1 to 2 cm from the root tip compared with that of the control sample. Because the root continued to grow without showing any damage of plasma membrane during the Al treatment, it was suggested that the 38 K uptake was not occurred through diffusion into the cells. The uptake of 38 K in both treatments, with/without Al, was decreased by VO4 3- (inhibitor of H+ -ATPase on plasma membrane) and DNP (H+ ionophore) treatment, which suggested that the K+ uptake was performed through an active transport, such as H+ :K+ transport or H+ gradient promoted by an Al treatment. 相似文献
4.
【目的】研究镉(Cd)处理下水稻根系细胞壁果胶对Cd胁迫的响应,进一步深化Cd安全水稻材料根系细胞壁Cd的固持机制。【方法】以Cd安全水稻材料D62B为研究对象,普通材料Luhui17为对照进行水培试验。设4个Cd质量浓度处理：0 mg/L (CK)、0.5 mg/L (Cd0.5)、1.0 mg/L (Cd1)、2.0 mg/L (Cd2)。在水稻分蘖期采集根系样品,分析细胞壁多糖中果胶、半纤维1、半纤维2以及残渣部分的Cd含量,测定果胶糖醛酸含量、果胶酯化度、果胶甲酯酶(PME)活性、根系过氧化氢(H2O2)含量以及细胞壁过氧化物酶(POD)活性,进而分析根系细胞壁果胶对Cd的响应特征。【结果】1) Cd胁迫下,D62B和Luhui17根系细胞壁果胶合成增加,根系细胞壁低酯化和高酯化果胶糖醛酸含量均表现为D62B高于Luhui17。Cd处理下D62B根系细胞壁低酯化和高酯化果胶糖醛酸含量较对照分别增加了13.21%～71.82%和22.10%～64.27%,Luhui17分别增加了24.14%～137.86%和13.12%～41.26%。... 相似文献
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6.
Yoshitake Hayashi Keitaro Tanoi Hiroyuki Nishiyama Tomoko M. Nakanishi 《Soil Science and Plant Nutrition》2005,51(5):729-731
To study the mechanisms of Al tolerance in rice, we focused on the change of rhizosphere pH. The 4-d seedlings were treated with Al solution (0, 10, 50 mM) for 24 h. Then each sample was put on an agarose gel including bromocresol green, so that the color of the gel indicated pH change. During 2-h contact, the pH of rhizosphere was decreased gradually, especially for Al-treated samples, showing the specific pH profiles along the root axis. Pretreatment of sample plants with a decoupling reagent 2,4-dinitrophenol (DNP) or a plasma membrane H+ -ATPase inhibitor Na3 VO4 did not decrease rhizosphere pH. Therefore, it was suggested that the H+ secretion activity was involved with Al-tolerant mechanisms of rice. 相似文献
7.
Carbon, Al and Fe (Cpyr , Alpyr and Fepyr ) were extracted with 0.1 m Na4 P2 O7 from 26 A horizon samples of tropical Thai and temperate Korean soils (Ultisols, Alfisols, Oxisols and Inceptisols). The soils, except for one Thai Inceptisol, had similar total C (0.35–3.29%) and Cpyr /total C ratios (0.20–0.41). There were approximately linear relationships between total C or Cpyr and clay content; two groups of soils gave different linear relationships. A curvilinear relationship between Cpyr and (Al + Fe)pyr (milli-atom kg−1 ) that can be approximated by an equation: Cpyr = 53 (Alpyr + Fepyr )1/2 – 24 was also found for most Thai and Korean soils. The above relationships indicated that total C and Cpyr would be close to zero at zero clay or zero (Al + Fe)pyr . It was inferred that clay-humus interaction has a primary importance in the determination of humus content in red and yellow soils in tropical and temperate regions and that the main role of clay is to supply Al and Fe that complex and stabilize humus against microbial degradation. 相似文献
8.
We compared the effects of saline stress (9:1 molar ratio of NaCl : Na2 SO4 , pH 6.44–6.65) and alkaline stress (9:1 molar ratio of NaHCO3 : Na2 CO3 , pH 8.71–8.89) on the germination, growth, photosynthesis, ionic balance and activity of anti-oxidant enzymes of Lathyrus quinquenervius to elucidate the physiological adaptive mechanism of plants to alkaline stress (high pH). The results showed that, at a low stress intensity, the effects of saline stress and alkaline stress on L. quinquenervius were similar. Compared with saline stress, high alkaline stress intensity clearly inhibited germination, growth, photosynthesis and root system activity, and led to a sharp increase in Na+ and an ion imbalance in the shoots, as well as enhanced H2 O2 and malondialdehyde content, resulting in severe intracellular oxidative stress. The results indicated that the accumulation of organic acid was a central adaptive mechanism by which L. quinquenervius maintained intracellular ionic balance under alkaline stress. Lathyrus quinquenervius may enhance organic acid synthesis to remedy the shortage of negative charge resulting from the massive influx of Na+ and decreased inorganic anions. In addition, saline stress and low alkaline stress slightly enhanced the activities of superoxide dismutase (SOD) and ascorbate peroxidase (APX), but did not affect catalase (CAT) activity. However, strong alkaline stress significantly enhanced the activities of SOD and APX, and reduced CAT activity. We propose that enhancing the activities of SOD and APX may be a vital mechanism by which L. quinquenervius resists oxidative stress caused by alkaline stress. 相似文献
9.
小麦根尖细胞壁对铝的吸附/解吸特性及其与耐铝性的关系 总被引：6，自引：0，他引：6
研究了耐铝性明显差异的2个小麦基因型西矮麦1号(耐性)和辐84系(敏感)根系对铝毒胁迫的反应与根尖细胞壁组分以及细胞壁对铝的吸附和解吸的关系。结果表明,30mol/L.AlCl3可迅速抑制小麦根系伸长,但对辐84系根系伸长的抑制更为明显,且小麦根系相对伸长率随着铝浓度的提高而急剧降低。在30mol/L.AlCl3处理24h后,西矮麦1号根系伸长的抑制率为33.3%,而辐84系根系伸长的抑制率高达70.9%。小麦距根尖0～10.mm根段的铝含量和细胞壁中果胶糖醛酸含量显著高于10～20.mm根段,且前者对铝的累积吸附量明显大于后者;在0～10.mm根段,敏感基因型果胶含量高于耐性基因型,其根尖含铝量及根尖细胞壁对铝的吸附量都要大于后者。采用1.0.mol/L.NH3.H2O对细胞壁预处理2.h降低果胶甲基酯化程度后,耐性和敏感基因型根尖细胞壁对铝的累积吸附量分别降低了17.1%和20.9%,但对铝的累积解吸率没有影响。由此可见,小麦根尖是铝毒的主要位点,细胞壁果胶含量和果胶甲基酯化程度可能是导致不同小麦基因型根尖细胞壁对铝吸附量、铝积累量的差异及其对铝毒胁迫反应的差异的重要原因。 相似文献
10.
Abstract. The success of organic cropping systems depends on symbiotic N2 fixation by leguminous crops, and it is important to explore new management systems to improve the nitrogen input through N2 fixation. During two growing seasons the possible advantage of growing fababean ( Vicia faba L.) in ridges was studied in comparison to the traditional method on flat soil. Differences in soil physical parameters resulted in a significantly greater microbial activity and a deeper root system at the flowering stage when grown in the ridge than on the flat. Consequently, the amount of fixed N at flowering was significantly greater in ridges than in flat soil. However, during the period from flowering until harvest, when the major part of the N uptake and N2 fixation took place, the differences between the treatments disappeared. Average values for the growing season of fluorescein diacetate hydrolysis, arylamidase activity and arylsulphatase activity were significantly greater in the ridge than on the flat, and the microbial biomass-C, derived from substrate induced respiration (SIR), was on average 232 and 223 μg C g−1 soil in the ridge and on the flat, respectively. Measured total-N uptake, including root N (0–30 cm depth), ranged from 206 to 247 kg N ha−1 , of which 182–201 kg N ha−1 was fixed N. From 154 to 173 kg N ha−1 was removed in grain resulting in a soil-N balance of +28 kg N ha−1 in both years. However, by including estimates of total root N and rhizodeposition-N the soil-N balance ranged from +52 to +62 kg N ha−1 . 相似文献
11.
Olga Babourina Konstantin Voltchanskii Ian Newman Zed Rengel 《Soil Science and Plant Nutrition》2005,51(5):733-736
Potassium transport was investigated in the root elongation zone of Arabidopsis seedlings during the first minutes of Al3+ exposure, using the non-invasive MIFE microelectrode technique. To prevent pH changes during Al3+ application, and to separate aluminium from acidic stress, plants were pre-treated with 5 mM homoPIPES before addition of AlCl3 (pH 4.2). The 30-min treatment with 50 or 500 μM AlCl3 led to a significant increase in K+ efflux in solutions containing 100 μM CaCl2 . This efflux was suppressed by high concentrations of Ca2+ (10 mM) in the bathing solution. Our results suggest that elevated external Ca2+ activities can sustain K+ influx in the root elongation zone during Al3+ exposure either by maintaining [Ca2+ ]cyt or by affecting Al3+ uptake across the plasma membrane. 相似文献
12.
Plasma Membrane Lipids Are the Powerful Components for Early Stage Aluminum Tolerance in Triticale 总被引：1，自引：0，他引：1
Tadao Wagatsuma Satoru Ishikawa Matsuo Uemura Wataru Mitsuhashi Takeshi Kawamura Md. Shahadat Hossain Khan Keitarou Tawaraya 《Soil Science and Plant Nutrition》2005,51(5):701-704
The order of aluminum (Al) tolerance in triticale lines (ST2>ST22) after re-elongation in an Al-free 0.2 mM calcium (Ca) solution for 9 h (Ca period) following 1 h pretreatment with 20 μM Al (Al period) agreed with that after 24 h of Al treatment. Permeability of the plasma membrane (PM) of root-tip cells after the Ca period was significantly increased in Al-sensitive ST22. Al was accumulated more heavily in the root-tip portion of ST22 than in that of ST2, although similar amounts of malic and citric acid anions were released from both triticale lines. We established a new system examining lipid permeability using synthesized nylon-2,8 ultrathin and porous capsules trapped previously with 0.1% (w/v) methylene blue solution and coated thereafter with PM lipid isolated from root tips by a newly developed technique. Permeability of the PM lipid measured with time in 0.2 mM Ca with or without 50 μM Al photometrically ( A 680 ) was significantly greater in Al-sensitive ST22 after 5 min of Al treatment. This is the first report to directly show the primary and early role of PM lipid in Al tolerance in triticale. 相似文献
13.
Yu-Seon KIM Won PARK Hai NIAN Takayuki SASAKI Bunichi EZAKI Young-Seok JANG Gap-Chae CHUNG Hyun-Jong BAE Sung-Ju AHN 《Soil Science and Plant Nutrition》2010,56(1):140-149
Seventeen soybean cultivars were screened to discern differences in aluminum (Al) sensitivity. The Sowon (Al-tolerant) and Poongsan (Al-sensitive) cultivars were selected for further study by simple growth measurement. Aluminum-induced root growth inhibition was significantly higher in the Poongsan cultivar than in the Sowon cultivar, although the differences depended on the Al concentration (0, 25, 50, 75 or 100 μmol L–1 ) and the amount of exposure (0, 3, 6, 12 or 24 h). Damage occurred preferentially in the root apex. High-sensitivity growth measurements using India ink implicated the central elongation zone located 2–3 mm from the root apex. The Al content was lower 0–5 mm from the root apices in the Sowon cultivar than in the apices of the Poongsan cultivar when exposed to 50 μmol L–1 Al for 12 h. Furthermore, the citric acid exudation rate was more than twofold higher in the Sowon cultivar. Protein production of plasma membrane (PM) H+ -ATPase from the root apices (0–5 mm) was upregulated in the presence of Al for 24 h in both cultivars. This activity, however, decreased in both cultivars treated with Al and the Poongsan cultivar was more severely affected. We propose that Al-induced growth inhibition is correlated with changes in PM H+ -ATPase activity, which is linked to the exudation of citric acid in the root apex. 相似文献
14.
S. C. JARVIS 《European Journal of Soil Science》1987,38(3):443-451
The cation composition of solutions and leachates from small-diameter laboratory soil columns was examined over a 23-week period after the addition of lime (0, 3 and 6 t ha–1 ) and/or nitrogen fertilizer (0 or 200 kg N ha–1 ) to an acid soil (pH 4.2). Water was applied at regular intervals to the surface of the columns and 17 leachate samples collected. Initially, the pH of the leachate was high (6.6) in all treatments (including those without lime) but fell rapidly to approach a steady value of 3.8. Large losses of calcium occurred from all columns; the total equivalent amounts of lime lost ranged from 0.88 (no addition) to 2.38 (with added lime) t CaCO3 ha–1 High concentrations of aluminium (181–325 μM) were present in leachates from all treatments; the addition of 200 kg N ha–1 increased the leaching of Al by 94%; addition of lime also increased the amounts of Al leached (by 52%).
The pH of the soil solution (separated by centrifugation) was influenced by treatment, especially in the top 0–40 mm of the column. Aluminium concentration was related to pH, but the form of the relationship differed amongst the treatments. 相似文献
The pH of the soil solution (separated by centrifugation) was influenced by treatment, especially in the top 0–40 mm of the column. Aluminium concentration was related to pH, but the form of the relationship differed amongst the treatments. 相似文献
15.
Muthiah Edward Raja Somanahalli C. Anil Kumar Sri Y. Raju 《Soil Science and Plant Nutrition》2005,51(5):751-754
Boron deficiency is a major production constraint of Mango cv Alphonso in western coast, Maharashtra, India. The soils are sandy-loam, light, acidic in reaction and receive high annual precipitation of above 2,500 mm. The leaf and soil B status was low with an average of 23 and 0.25 mg kg−1 respectively. About 60% of the orchards were found to be deficient in B. The B adsorption study using Langmuir adsorption isotherm revealed that the adsorption capacity of B by these soils was low with an average adsorption maxima (b) of 16.62 μg g−1 and bonding energy constant ( K ) of 0.09 mL μg−1 making soil B susceptible to leaching. The Mango leaf N status was in excess range, which aggravated B deficiency through growth dilution. A significant negative correlation was observed between leaf B and leaf N (statistically significant at 1% level (p=0.01)). The free Al status of the soils was found to be fairly high, and its detrimental effect on root growth was observed which led to inefficient absorption of limited soil B by roots. The climatic conditions of Konkan like high humidity, high temperature and long sunshine hours also favored widespread incidence of B deficiency, low yield and poor quality. The response of Mango cv Alphonso to the B application was found to be more in foliar than in soil application. 相似文献
16.
The aim was to determine whether the addition of F to an acid soil reduces the concentration of free Al3+ and other forms that have been shown to be toxic to plants. The ability of two different extracts to reflect Al speciation in the soil solution was also investigated. Addition of F (0-5.2μmolg−1 ) to an acid soil (pH 4.15, soil solution) increased the pH and total concentrations of Al and F in the soil solution whereas Al3+ remained constant or decreased. Soil solution pH, total soluble Al and Al extracted by 0.01 m CaCl2 are not good predictors of the likelihood of aluminium toxicity in soils containing soluble fluoride. 相似文献
17.
The role of root border cells in aluminum resistance of pea (Pisum sativum) grown in mist culture 总被引：1，自引：0，他引：1
Min Yu Renfang Shen Jiayou Liu Rongfu Chen Miaomiao Xu Yong Yang Hongdong Xiao Huizhen Wang Huoyan Wang Changquan Wang 《植物养料与土壤学杂志》2009,172(4):528-534
Root border cells are considered to contribute to aluminum (Al) resistance by protecting the root apex from Al toxicity. In the present study, the responses of root apices of pea (Pisum sativum) to Al exposure in mist culture with border cells stripped off or not were compared. Inhibition of root elongation, induction of callose synthesis, and accumulation of Al were more pronounced in root apices stripped from border cells. Aluminum application led to higher Al concentrations in border cells than in root apices. The same trend was found for Al contents in cell walls of border cells compared to root apices. The analysis of cell‐wall pectin indicated that the concentrations of total sugars, uronic acids, and 2‐keto‐3‐deoxyoctonic acid (KDO) were higher in border cells than in root apices, especially when exposed to Al. Together, these results suggest that root border cells enhance the Al resistance of root apices by immobilizing Al in their cell‐wall pectin, thus protecting the root apex. 相似文献
18.
Salvador LD Suganuma T Kitahara K Tanoue H Ichiki M 《Journal of agricultural and food chemistry》2000,48(8):3448-3454
The cell wall materials (CWMs) from sweetpotato (Ipomoea batatas cv. Kokei 14), cassava (Manihot esculenta), and potato (Solanum tuberosum cv. Danshaku) and commercial sweetpotato fiber as well as their polysaccharide fractions were analyzed for sugar composition by the high-performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD) method. The separation of arabinose and rhamnose, and xylose and mannose, by this method has been improved using a CarboPac PA 10 column. Pretreatment of the CWMs and cellulose fractions with 12 M H(2)SO(4) was required for complete hydrolysis to occur. Commercial sweetpotato fiber was found to be mainly composed of glucose (88.4%), but small amounts of other sugars were also detected. Among the root crops, sweetpotato CWM had the highest amount of pectin and galacturonic acid. Fucose was detected only in cassava CWM and its hemicellulose fraction, while galactose was present in the highest amount in potato CWM. Among the polysaccharide fractions, it was only in the hemicellulose fraction where significant differences in the sugar composition, especially in the galactose content, were observed among the root crops. 相似文献
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20.
F. P. C. Blamey C. J. Asher D. C. Edwards G. L. Kerven 《Journal of plant nutrition》2013,36(4):555-562
Little is known about the primary effects of aluminum (Al) in reducing root growth. However, the sorption of Al by the root cell wall, particularly by calcium (Ca) pectate, has been suggested as being important in the expression of Al toxicity in plants. To overcome problems arising from the close proximity of root cell components that may react with Al, a synthetic Ca pectate membrane was prepared as a model system for Al studies. Solution containing 1 mM Ca (as CaCl2) was passed through the membrane, and the flow rate measured. Solution containing 29 μM Al (as AlCl3) and 1 mM Ca reduced solution flow rate by > 80% from c. 3.5 to c. 0.6 mL/min within 2 min, with a further slight decline over the next 4 min. The Al concentration in solution proximate to the inlet side of the membrane decreased to 15 μM within 10 min, and only 3 μM Al was measured in solution that had passed through the membrane. These results suggest that an important primary effect of toxic Al is a reduction in water movement into the root, with consequent effects on water relations in the plant. 相似文献