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1.
Role of roots in cadmium accumulation of two water spinach cultivars: reciprocal grafting and histochemical experiments 总被引:1,自引:0,他引:1
Junliang Xin Baifei Huang Junzhi Yang Zhongyi Yang Jiangang Yuan Yangxiu Mu 《Plant and Soil》2013,366(1-2):425-432
Background and Aims
Cultivars of water spinach (Ipomoea aquatica Forsk.) differ widely in their shoot cadmium (Cd) concentration. Previously, we suggested that low-Cd cultivars are better able to retain Cd in their roots and thus prevent root-to-shoot Cd translocation. In this study, we explored the roles of roots and shoots in Cd accumulation in a high-Cd (T308) and low-Cd cultivar (QLQ).Methods
We used reciprocal grafting to determine the importance of roots and shoots in Cd accumulation, and a dithizone histochemical method to investigate Cd distribution in the roots.Results
The T308 scion with QLQ rootstock accumulated less Cd than the shoot of non-grafted T308. The QLQ scion with T308 rootstock showed a significantly higher Cd concentration than that in the shoot of non-grafted QLQ. Cadmium induced thicker phellem formation in the main roots of QLQ than in those of T308 and only QLQ showed thickening of the outer cortex cell walls in lateral roots.Conclusions
Shoot Cd accumulation was primarily determined by root-to-shoot Cd translocation, not root Cd uptake. The thicker phellem and outer cortex cell walls in QLQ than in T308 may be one reason why QLQ roots were able to retain more Cd, and thus reducing Cd translocation to shoots. 相似文献2.
Junliang Xin Baifei Huang Zhongyi Yang Jiangang Yuan Yadong Zhang 《Plant and Soil》2013,372(1-2):431-444
Aims
Mechanisms of low cadmium (Cd) accumulations in cultivars of water spinach are poorly investigated. We aimed to improve understanding of the subcellular biochemical properties of the mechanisms involved.Methods
A pot experiment was conducted to investigate the subcellular distributions of Cd in lateral and main roots, stems, and young and old leaves of a high-Cd (T308) and a low-Cd cultivar (QLQ).Results
The ratio of main root:lateral roots Cd concentration in QLQ was lower (0.34–0.35) than that in T308 (0.39–0.55). The ratio of stem:main root Cd concentration in QLQ was much lower (0.60–0.73) than that in T308 (1.19–1.58). QLQ has higher capacity to sequester Cd in cell wall fractions of main and lateral roots than T308.Conclusions
The difference in shoot Cd concentration between QLQ and T308 is attributable to the difference in Cd translocation from lateral to main roots and from roots to the stem. Fixation of large amounts of Cd in old leaves is beneficial to protect young leaves from Cd toxicity. Cadmium immobilization by the cell wall is important in Cd detoxification, especially in main and lateral roots of QLQ and the shoot of T308. 相似文献3.
Aims
The current study aimed to assess the potential of peanut (Arachis hypogaea L.) for bioenergy production via phytoextraction in cadmium (Cd) -contaminated soils and screen appropriate cultivars for this approach.Methods
A life-cycle pot experiment was conducted to determine the biomass, seed yield, oil content and Cd accumulation of seven peanut cultivars under Cd concentration gradients of 0, 2, and 4 mg kg?1.Results
Peanut exhibits genotypic variations in Cd tolerance, seed production, oil content, and Cd accumulation. Exposure of plants to 2 and 4 mg kg?1 Cd did not inhibit shoot biomass, seed yield, and oil content for most of the cultivars tested. There are large amounts of Cd accumulated in the shoots. Although the seed Cd concentration of peanut was relatively high, the Cd concentration in seed oils was very low (0.04-0.08 mg kg?1). Among the cultivars, Qishan 208 showed significant Cd tolerance, high shoot biomass, high pod and seed yield, high seed oil content, considerable shoot Cd concentration, and the largest translocation factor and total Cd in shoots.Conclusions
The cultivation of peanut in Cd-contaminated farmland was confirmed to be feasible for bioenergy production via phytoextraction, and Qishan 208 is a good candidate for this approach. 相似文献4.
Variation in cadmium accumulation and translocation among peanut cultivars as affected by iron deficiency 总被引:2,自引:0,他引:2
Purpose
The current study aimed to test the hypothesis that the variations in shoot Cd accumulation among peanut cultivars was ascribed to the difference in capacity of competition with Fe transport, xylem loading and transpiration.Methods
A hydroponics experiment was conducted to determine the plant biomass, gas exchange, and Cd accumulation in Fe-sufficient or -deficient plants of 12 peanut cultivars, at low Cd level (0.2 μM CdCl2).Results
Peanut varied among cultivars in morpho-physiological response to Cd stress as well as Cd accumulation, translocation and distribution. Qishan 208 and Xvhua 13 showed a higher capacity for accumulating Cd in their shoots. Fe deficiency increased the concentration and amount of Cd in plant organs, but decreased TF root to shoot and TF root to stem, while TF stem to leaf remained unaffected. Fe deficiency-induced increase rates of Cd concentration and total Cd amount in roots and leaves were negatively correlated with the values in Fe-sufficient plants. Transpiration rate was positively correlated with leaf Cd concentration, TF root to shoot, TF root to stem and TF stem to leaf.Conclusions
The difference in shoot Cd concentration among peanut cultivars was mainly ascribed to the difference in Fe transport system, xylem loading capacity and transpiration. 相似文献5.
6.
Background and aims
Irrigation strategies for glasshouse tomato are often based on solar radiation sums. However, due to new energy-saving climate control, current strategies might result in inappropriate irrigation. Because of the limited water buffering capacity of soilless growing media like rockwool, this could have adverse effects on fruit production and quality. We present an overview of tomato plant ecophysiological responses to substrate water availability to allow the evaluation of mechanistic hypotheses about internal plant water storage and depletion and reversible stem-fruit water transport.Methods
The hydraulic properties of the growing medium were determined and plant water uptake, stem and fruit diameter variations were studied.Results
A low substrate matric suction (?2 to ?3?kPa) had a significant effect on stem and fruit growth dynamics. The substrate water retention curve indicated a sharp decrease in hydraulic conductivity, limiting the water availability for plant roots significantly.Conclusions
The hydraulic properties of the growing medium are of utmost importance for plant water uptake, and should therefore be incorporated in plant models describing water flow. Internally stored water responds instantaneously to varying water availability and rates of water backflow from tomato fruits can be quite substantial. 相似文献7.
CaGLK2 regulates natural variation of chlorophyll content and fruit color in pepper fruit 总被引:1,自引:0,他引:1
Arnon Brand Yelena Borovsky Theresa Hill Khalis Afnan Abdul Rahman Aharon Bellalou Allen Van Deynze Ilan Paran 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2014,127(10):2139-2148
8.
Background and aims
Accumulation of Cd in the shoots of plants grown on Cd contaminated soils shows considerable variation. A previous preliminary experiment established that one major reason for this variation was the rate of Cd influx into the roots (mol Cd cm?2 root s?1). However, this experiment did not distinguish between solubilization of soil Cd on the one hand and difference in Cd uptake kinetics on the other. The main objectives of the present study were thus to characterize Cd uptake kinetics of plants continuously exposed to Cd concentrations similar to those encountered in soils. Furthermore we determined the factors responsible for differences in shoot Cd concentration such as net Cd influx, root area-shoot dry weight ratio, shoot growth rate and proportion of Cd translocated to the shoot.Materials and methods
Maize, sunflower, flax and spinach were grown in nutrient solution with five constant Cd concentrations varying from 0 to 1.0 μmol?L?1. Root and shoot parameters as well as Cd uptake were determined at two harvest dates and from these data Cd net influx and shoot growth rates were calculated.Results and conclusions
Cadmium uptake kinetics, i.e. the net Cd influx vs. Cd solution concentration followed a straight line. Its slope is the root absorbing power, α, $ \left( {\alpha ={{{\mathrm{Cd}\;\mathrm{net}\;\mathrm{influx}}} \left/ {{\mathrm{Cd}\;\mathrm{solution}\;\mathrm{concentration}}} \right.}} \right) $ . The α values of spinach and flax were about double that of maize and sunflower (5?×?10?6?cm?s?1 vs. 2.5?×?10?6?cm?s?1). Spinach and flax had a 3–5 times higher shoot Cd concentration than maize and sunflower. The difference in shoot Cd concentration was partly due to the higher Cd influx but also to a higher translocation of Cd from root to shoot and also to a slower shoot growth rate. 相似文献9.
Boron uptake and translocation in some cotton cultivars 总被引:1,自引:0,他引:1
Julio C. Bogiani Thalita F. Sampaio Cassio H. Abreu-Junior Ciro A. Rosolem 《Plant and Soil》2014,375(1-2):241-253
Aims
Boron (B) is the most deficient micronutrient in cotton (Gossypium hirsutum L.). It is generally accepted that B is immobile in cotton phloem, but some cultivars could remobilize the nutrient. In order to further understand B uptake and mobility in various cotton cultivars two experiments were conducted.Methods
In experiment-1, cotton cultivars were grown in 10B enriched or natural abundance nutrient solutions for 4 weeks and transferred to nutrient solutions ranging from deficient to sufficient in B. In experiment-2 10B enriched boric acid was applied to cotton leaves and B mobilization was determined.Results
In deficient plants, B previously supplied to roots was remobilized from older to younger plant tissues, but the amount was insufficient to maintain growth. Boron deficiency symptoms appeared and progressed with time. Boron applied to leaves was taken up and remobilized within 24 h. Boron mobilization was higher to plant parts above the treated region.Conclusion
Boron uptake and mobilization was similar among cotton cultivars. Boron applied to cotton leaves shows a preferential translocation to younger tissues. Foliar sprays of B to cotton may be used to cope with a temporary deficiency, but to achieve full growth and development B must be available to cotton throughout the plant cycle. 相似文献10.
Non-destructive estimation of root mass using electrical capacitance on ten herbaceous species 总被引:1,自引:0,他引:1
Background and Aims
Characteristically baseline levels of Sb in the environment are low, but problematic local elevation trends arise from anthropogenic activities such as mining and incineration. Arsenic (analog of Sb) accumulation by rice can be reduced by iron (Fe) plaque. A hydroponic experiment was conducted to investigate whether Fe plaque could reduce the uptake and translocation of different Sb species in different rice cultivars.Methods
After Fe plaque on rice roots was induced in solution containing 0, 0.2, 0.4, 0.7, 1.2, 2.0?mM Fe2+ for 24?h, seedlings were transferred into nutrient solution with 20?μM Sb(V) or Sb(III) for 3?d.Results
About 60–80% (Sb(III) treatment) and 40–60% (Sb(V) treatment) of the total Sb accumulated in Fe plaque. There was a significant correlation between the concentrations of Sb and Fe on the root surface. A similar relationship was observed in roots and shoots. Cultivar (Jiahua 1) formed the most Fe plaque, had the highest Fe associated Sb sequestration but the lowest Sb concentration in the root interior.Conclusions
Fe plaque may act as a ‘buffer’ for Sb(V) and Sb(III) in the rhizosphere, and cultivars played an important role in the different species Sb uptake and translocation. 相似文献11.
Qian Zhou Yu-Chen Yang Chuang Shen Chun-Tao He Jian-Gang Yuan Zhong-Yi Yang 《Plant and Soil》2017,420(1-2):223-237
12.
Does radial oxygen loss and iron plaque formation on roots alter Cd and Pb uptake and distribution in rice plant tissues? 总被引:5,自引:0,他引:5
Background and Aims
Metal (e.g. Cd and Pb) pollution in agricultural soils and crops have aroused considerable attention in recent years. This study aimed to evaluate the effects of ROL and Fe plaque on Cd and Pb accumulation and distribution in the rice plant.Methods
A rhizobag experiment was employed to investigate the correlations among radial oxygen loss (ROL), Fe plaque formation and uptake and distribution of Cd and Pb in 25 rice cultivars.Results
Large differences between the cultivars were found in rates of ROL (1.55 to 6.88 mmol O2 kg?1 root d.w. h?1), Fe plaque formation (Fe: 6,117–48,167 mg kg?1; Mn: 127–1,089 mg kg?1), heavy metals in shoot (Cd: 0.13–0.35 mg kg?1; Pb: 4.8–8.1 mg kg?1) and root tissues (Cd: 1.1–3.5 mg kg?1; Pb: 45–199 mg kg?1), and in Fe plaque (Cd: 0.54–2.6 mg kg?1; Pb: 102–708 mg kg?1). Rates of ROL were positively correlated with Fe plaque formation and metal deposition on root surfaces, but negatively correlated with metal transfer factors of root/plaque and distributions in shoot and root tissues.Conclusions
ROL-induced Fe plaque promotes metal deposition on to root surfaces, leading to a limitation of Cd and Pb transfer and distribution in rice plant tissues. 相似文献13.
De-Chun Liu Qiong Zeng Qing-Xun Ji Chuan-Fu Liu Shan-Bei Liu Yong Liu 《Plant cell reports》2012,31(12):2239-2246
Key message
The altered ultrastructure and composition of cuticular wax from ‘glossy Newhall’ (MT) fruits lead to its glossy phenotype.Abstract
A novel mutant derived from the wild-type (WT) ‘Newhall’ navel orange (Citrus sinensis [L.] Osbeck cv. Newhall), named ‘glossy Newhall’ (MT), which produced much more glossy fruits that were easily distinguishable from the WT fruits was characterized in this report. The total wax loads of both WT and MT fruits varied considerably during the fruit development. The most abundant wax fraction of WT mature fruits was triterpenoids, followed by aldehydes, alkanes, fatty acids, primary alcohol and cholesterol. The total wax load in MT mature fruits was reduced by 44.2?% compared with WT. Except for the minor wax components of primary alcohol and cholesterol, the amounts of all major wax fractions in MT mature fruits were decreased in varying degrees. The major reduction occurred in aldehydes that decreased 96.4?% and alkanes that decreased 81.9?%, which was consistent with scanning electron micrographs of MT mature fruit surfaces that showed a severe loss of wax crystals. Hence, aldehydes and alkanes were suggested to be required for wax crystal formation in ‘Newhall’ navel orange fruits. 相似文献14.
Cynthia Grant Don Flaten Mario Tenuta Sukhdev Malhi Wole Akinremi 《Plant and Soil》2013,372(1-2):221-233
Background and aims
Limited information is available on how cadmium (Cd) applied in phosphate fertilizer interacts with soil and environmental conditions over time to affect crop Cd concentrations.Methods
Field studies from 2002 to 2009 at seven locations evaluated the cumulative effects of P fertilizer rate and Cd concentration on seed Cd concentration of durum wheat (Triticum turgidum L.) and flax (Linum usitatissiumum L.).Results
Soil characteristics and environment affected Cd availability. Durum wheat grain Cd increased with P fertilizer rate but effect on flaxseed Cd concentration was smaller. Cadmium concentration in fertilizer had a greater effect on flaxseed than durum wheat Cd concentration. Seed Cd concentration of both crops was greatest with the highest rate P fertilizer containing the highest Cd concentration. There was not a strong cumulative effect of fertilization over the 8 years of the study, indicating attenuation of Cd availability over time.Conclusions
Cadmium in phosphate fertilizer increases Cd available for crop uptake, but crop Cd concentration is also affected by soil characteristics and annual environmental conditions. Type of crop produced and soil and environmental characteristics that affect phytoavailability must be taken into account when assessing the Cd risk from P fertilization. 相似文献15.
Junguo Bi Zhenghui Liu Zhaomiao Lin Md A. Alim Muhammad I. A. Rehmani Ganghua Li Qiangsheng Wang Shaohua Wang Yanfeng Ding 《Plant and Soil》2013,369(1-2):231-240
Background and aims
This study aims to investigate the effect of nitrogen (N) on grain phosphorus (P) accumulation in japonica rice.Methods
Six cultivars with contrasting agronomic traits were grown for 3 years (from 2008 to 2010) of field experiments under seven N treatments and 1 year (in 2010) of pot experiments with five N treatments to study the effect of N on grain phosphorus accumulation and to explore its physiological foundation.Results
Grain total P and phytic acid concentration showed a clearly decreasing trend as N rate increased for both field and pot experiments. Pot experiment revealed that application of N increase plant biomass, but tended to lower plant P uptake, especially for the split topdressing treatments. Both harvest index (HI) and P harvest index (PHI) increased with N rate, but PHI was consistently higher than HI, indicating the larger proportion of P translocation to grain than that of dry matter by N. Further, ratio of PHI/HI differed significantly among genotypes, but was stable across contrasting N treatments.Conclusions
The combination of decreased plant P uptake and dilution effect of increased grain yield by N is proposed as underlying mechanism of the decreased grain P concentration by high N. 相似文献16.
Jean-Marc Custos Christian Moyne Tiphaine Treillon Thibault Sterckeman 《Plant and Soil》2014,374(1-2):497-512
Background and aims
Chelant-enhanced phytoextraction has given variable and often unexplained experimental results. This work was carried out to better understand the mechanisms of Cd plant uptake in the presence of EDTA and to evaluate the contributions of Cd-EDTA complexes to the uptake.Method
A 1-D mechanistic model was implemented, which described the free Cd2+ root absorption, the dissociation and the direct absorption of the Cd-EDTA complexes. It was used to explain Cd uptake by maize in hydroponics and in soil.Results
In hydroponics, the addition of EDTA caused a decrease in Cd uptake by maize, particularly when the ratio of total EDTA ([EDTA] T ) to total Cd ([Cd] T ) was greater than 1. At [Cd] T = 1 μM, when [EDTA] T /[Cd] T < 1, the model indicated that Cd uptake was predominantly due to the absorption of free Cd2+, whose pool was replenished by the dissociation of Cd-EDTA. When [EDTA] T /[Cd] T > 1, the low Cd uptake was mostly due to Cd-EDTA absorption. In soil spiked with 5 mg Cd kg?1, Cd uptake was not affected by the various EDTA additions, because of the buffering capacity of the soil solid phase.Conclusions
Addition of EDTA to soil increases Cd solubility but dissociation of Cd-EDTA limits the availability of the free Cd2+ at the root surface, which finally reduces the plant uptake of the metal. 相似文献17.
Fabian Koeslin-Findeklee Andreas Meyer Andreas Girke Katrin Beckmann Walter J. Horst 《Plant and Soil》2014,384(1-2):347-362
Aims
Winter oilseed rape (Brassica napus L.) cultivation causes high nitrogen (N) balance surpluses. The breeding and cultivation of N-efficient cultivars (high grain yield under low N supply) can contribute to the reduction of the crop-specific N surpluses. Comparing line cultivars with hybrids and dwarfs the hypothesis was tested if stay-green into reproductive growth contributes to superior N efficiency of hybrids and dwarfs.Methods
The present work comprised two years field experiments with ten line, five hybrid and three dwarf cultivars and hydroponic experiments with three hybrid and nine line cultivars.Results
Hybrids were superior in yield formation independent of the N supply. The greater N efficiency of the hybrids was related to a higher N uptake until maturity, but not to stay-green. This was in agreement with a hydroponic experiment in which the hybrids were particularly responsive in N starvation-induced leaf senescence of older leaves as revealed by SPAD, photosynthesis and the expression of the senescence-specific cysteine protease gene SAG12-1. Additionally, hybrids were characterized by an efficient N retranslocation from vegetative to reproductive plant organs in combination with a lower grain-N concentration.Conclusions
Both, N uptake and N utilization efficiency were decisive for the superior N efficiency of the hybrids. 相似文献18.
19.
Aims
The main aim of this study was to validate the HYDRUS-2D model for the simulation of Cd, Cu, Pb and Zn transport within a soil column and their accumulation by willows.Methods
A simulation of metal transport and uptake by willow was implemented using the HYDRUS-2D code. Two scenarios of the column experiment were compared: soil (C) and soil with planted willows (V). Seeping water, soil water content and actual transpiration were measured. Metal contents in soil water and willows were analysed.Results
The single-porosity model (applied for isotropic soil media) was sufficient for scenario C. The single-porosity (applied for anisotropic soil media) and dual-porosity models (characterizing non-equilibrium water flow) were explored in scenario V. Measured cumulative Cd and Zn uptake showed a 20- and 10-times higher accumulation, respectively, in comparison with the modelled ones. On the other hand, modelled cumulative Pb uptake was reduced by reducing the maximum value of the root uptake concentration c Root .Conclusions
The HYDRUS-2D program was usable for modelling of Cd, Cu, Pb and Zn transport and their willow uptake. Additionally, consideration of dual-porosity soil media as well as anisotropy was suitable for the experiment with roots presence in the soil. 相似文献20.
Predicting zinc bioavailability to wheat improves by integrating pH dependent nonlinear root surface adsorption 总被引:1,自引:0,他引:1
Andreas Duffner Ellis Hoffland Liping Weng Sjoerd E. A. T. M. van der Zee 《Plant and Soil》2013,373(1-2):919-930