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1.
Aims
Iron (Fe) is an essential micronutrient, and plant available Fe is often limited in alkaline soils. Fe deficiency chlorosis decreases plant growth and yield. Identification of germplasm with high and low Fe use efficiency will allow studies to better understand the genetic components for breeding Fe efficient varieties.Methods
A screen using cucumber (Cucumis sativus) seedlings identified varieties that maintained contrasting levels of chlorophyll under Fe deficiency or limitation. A time course of mineral dynamics in cotyledons was conducted.Results
The variety Ashley had the highest chlorophyll under Fe deficiency and per unit Fe in the leaf, while the variety Miniature White had the lowest. Ashley also maintained higher chlorophyll when challenged with low Fe or bicarbonate, accumulated greater quantities of Fe, and had higher root ferric reductase activity. Cotyledons accumulated minerals for the first several days, then Fe, P, K, and Cu were remobilized. The Fe use efficient and inefficient varieties remobilized Fe and P on different timescales.Conclusions
Our results suggest that this screen can identify varieties for systems level studies that could elucidate factors needed for Fe use efficiency and remobilization of minerals. The time course indicated that cotyledon Fe stores did not contribute to seedling Fe use efficiency. 相似文献2.
Background and aims
Iron deficiency chlorosis (IDC) leads to severe leaf chlorosis, low photosynthetic rates, and yield reductions of several million metric tonnes each year. In order to devise breeding and genetic transformation programs that aim at generating high-yielding and IDC-tolerant soybean lines, it is necessary to better understand the mechanisms that enable tolerant plants to survive under Fe-limiting conditions.Methods
An in silico analysis in the USDA soybean collection allowed the identification of a set of novel efficient and inefficient soybean cultivars which can be used in future studies concerning IDC response. Plants were grown in iron deficient and iron sufficient conditions using a bicarbonate system and several IDC-related aspects were studied.Results
A new set of efficient and inefficient soybean lines were identified in silico, and their tolerance to IDC was confirmed under laboratorial conditions. New plant traits that are highly correlated to IDC scoring were identified: a negative correlation was found between SPAD values and stem weight, weight of the unifoliolates and iron concentration of the first unifoliolates was found; higher SPAD values were correlated with the amount of iron in the first trifoliate leaves. Our data also show that having higher concentrations of iron in the seeds provides increased resistance to IDC. No correlation was found between root iron reductase activity and chlorosis.Conclusions
Soybean differential chlorosis susceptibility between different accessions is linked to specific morpho-physiological parameters such as unifoliolate leaf size, stem weigh, concentration of iron in the seeds, and tissue iron partitioning. 相似文献3.
Roots from cuttings of grapevine rootstocks V. Berlandieri × V. rupestris 140 Ru, V. Berlandieri × V. riparia SO4, V. riparia × V. rupestris 101–14 and a V. vinifera cultivar (Pinot blanc), with a decreasing degree of chlorosis resistance, were excised and tested to quantify physiological and morphological parameters, as follows: 59Fe uptake from an FeEDTA solution; reducing capacity; root diameter and root hair occurrence.The most significant findings are that: a) 59Fe uptake and FeEDTA reduction decreased from the most chlorosis resistant rootstock (140 Ru) to the most susceptible one (101–14) and to Pinot blanc; b) 59Fe uptake and reducing capacity were closely related; c) iron uptake and reduction were closely related to the root diameter and root hair occurrence, within the rootstocks. 相似文献
4.
《Plant Physiology and Biochemistry》2007,45(5):315-322
Morpho-physiological responses to bicarbonate-induced Fe deficiency were investigated in five Vitis vinifera L. Tunisian varieties (Khamri, Blanc3, Arich Dressé, Beldi, and Balta4). One-month-old woody cuttings were cultivated for 85 days on a free calcareous soil irrigated with tap water containing increasing bicarbonate levels (0, 4, 8, 12, and 16 mM NaHCO3). After this screening, a second experiment compared root biochemical responses of two contrasting genotypes (tolerant-sensitive) dealing with bicarbonate-induced iron deprivation (20 μM Fe ± 10 mM HCO3−) for 75 days. Using morpho-physiological criteria, grapevine tolerance to HCO3−-induced Fe shortage appeared to be genotype-dependent: Balta4 and Beldi varieties showed the highest leaf-chlorosis score (especially at the extreme HCO3− levels), in contrast to Khamri variety. Growth parameters (shoot height, total leaf area, leaf number, and biomass production) as well as juvenile leaf chlorophyll content were also differently affected depending on both genotype and bicarbonate dose. At 16 mM HCO3−, Khamri was the less sensitive variety, contrasting with Balta4. On the other hand, chlorophyll content correlated positively with HCl-extractible Fe content of the juvenile leaves, suggesting that the grapevine response to iron deficiency may partly depend on to the plant ability to adequately supply young leaves with this element. Root biochemical responses revealed a relatively higher root acidification capacity in Khamri (tolerant) under Fe-deficiency while no significant changes occurred in Balta4 (sensitive). In addition, Fe(III)-reductase and phosphoenolpyruvate carboxylase (PEPC, EC 4.1.1.31) activities were strongly stimulated by Fe-deficiency in Khamri, while remaining constant in Balta4. These findings suggest that biochemical parameters may constitute reliable criteria for the selection of tolerant grapevine genotypes to iron chlorosis. 相似文献
5.
Hamdi El-Jendoubi Ernesto Igartua Javier Abadía Anunciación Abadía 《Plant and Soil》2012,354(1-2):121-139
Background and Aims
The possibility of using tree materials in early phenological stages, such as dormant buds and flowers, for the prognosis of Fe deficiency occurring later in the year has been studied in peach and pear trees.Methods
Thirty-two peach trees and thirty pear trees with different Fe chlorosis degrees were sampled in different commercial orchards. In peach, samples included flower buds, vegetative buds, bud wood, flowers and leaves at 60 and 120?days after full bloom (DAFB). In pear, samples included buds, bud wood, flowers and leaves at 60 and 120?days DAFB. Leaf chlorophyll was assessed (SPAD) at 60 and 120 DAFB. Sampling was repeated for 3–5?years depending on the materials. Mineral nutrients measured were N, P, K, Ca, Mg, Fe, Mn, Zn and Cu.Results
The relationships between the nutrient concentrations in the different materials and leaf SPAD were assessed using four different statistical approaches: i) comparison of means depending on the chlorosis level, ii) correlation analysis, iii) principal component analysis, and iv) stepwise multiple regression. In all cases, significant associations between nutrients and SPAD were found. The best-fit multiple regression curves obtained for the multi-year data set provided good prediction in individual years.Conclusions
Results found indicate that it is possible to carry out the prognosis of Fe chlorosis using early materials such as buds and flowers. The relationships obtained were different from those obtained in previous studies using a single orchard. The different methods of analysis used provided complementary data. 相似文献6.
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7.
Aims
This study evaluated how iron nutrition affect leaf anatomical and photosynthetic responses to low cadmium and its accumulation in peanut plants.Methods
Seedlings were treated with Cd (0 and 0.2 μM CdCl2) and Fe (0, 10, 25, 50 or 100 μM EDTA-Na2Fe) in hydroponic culture.Results
Cadmium accumulation is highest in Fe-deficient plants, and dramatically decreased with increasing Fe supply. The biomass, gas exchange, and reflectance indices were highest at 25 μM Fe2+ treatments, indicating the concentration is favorable for the growth of peanut plants. Both Fe deficiency and Cd exposure impair photosynthesis and reduce reflectance indices. However, they show different effects on leaf anatomical traits. Fe deficiency induces more and smaller stomata in the leaf surface, but does not affect the inner structure. Low Cd results in a thicker lamina with smaller stomata, thicker palisade and spongy tissues, and lower palisade to spongy thickness ratio. The stomatal length and length/width ratio in the upper epidermis, spongy tissue thickness, and palisade to spongy thickness ratio were closely correlated with net photosynthetic rate, stomatal conductance, and transpiration rate.Conclusions
Cd accumulation rather than Fe deficiency alters leaf anatomy that may increase water use efficiency but inhibit photosynthesis. 相似文献8.
Abscisic acid alleviates iron deficiency by promoting root iron reutilization and transport from root to shoot in Arabidopsis 总被引:1,自引:0,他引:1
Abscisic acid (ABA) has been demonstrated to be involved in iron (Fe) homeostasis, but the underlying mechanism is largely unknown. Here, we found that Fe deficiency induced ABA accumulation rapidly (within 6 h) in the roots of Arabidopsis. Exogenous ABA at 0.5 μM decreased the amount of root apoplastic Fe bound to pectin and hemicellulose, and increased the shoot Fe content significantly, thus alleviating Fe deficiency‐induced chlorosis. Exogenous ABA promoted the secretion of phenolics to release apoplastic Fe and up‐regulated the expression of AtNRAMP3 to enhance reutilization of Fe stored in the vacuoles, leading to a higher level of soluble Fe and lower ferric–chelate reductase (FCR) activity in roots. Treatment with ABA also led to increased Fe concentrations in the xylem sap, partially because of the up‐regulation of AtFRD3, AtYSL2 and AtNAS1, genes related to long‐distance transport of Fe. Exogenous ABA could not alleviate the chlorosis of abi5 mutant resulting from the significantly low expression of AtYSL2 and low transport of Fe from root to shoot. Taken together, our data support the conclusion that ABA is involved in the reutilization and transport of Fe from root to shoot under Fe deficiency conditions in Arabidopsis. 相似文献
9.
Mechanism of Fe uptake by the leaf symplast: Is Fe inactivation in leaf a cause of Fe deficiency chlorosis? 总被引:5,自引:0,他引:5
The mechanism of iron (Fe) uptake from the leaf apoplast into leaf mesophyll cells was studied to evaluate the putative Fe
inactivation as a possible cause of Fe deficiency chlorosis. For this purpose, sunflower (Helianthus annuus L.) and faba bean
plants (Vicia faba L.) were precultured with varied Fe and bicarbonate (HCO
3
-
) supply in nutrient solution. After 2–3 weeks preculture, FeIII reduction and 59Fe uptake by leaf discs were measured in solutions with Fe supplied as citrate or synthetic chelates in darkness. The data
clearly indicate that FeIII reduction is a prerequisite for Fe uptake into leaf cells and that the Fe nutritional status of plants does not affect either
process. In addition, varied supply of Fe and HCO
3
-
to the root medium during preculture had no effect on pH of the xylem sap and leaf apoplastic fluid. A varied pH of the incubation
solution had no significant effect on FeIII reduction and Fe uptake by leaf discs in the physiologically relevant pH range of 5.0–6.0 as measured in the apoplastic leaf
fluid. It is concluded that Fe inactivation in the leaf apoplast is not a primary cause of Fe deficiency chlorosis induced
by bicarbonate.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
10.
Antonio Rafael Sánchez-Rodríguez María Carmen del Campillo José Torrent 《Plant and Soil》2013,373(1-2):31-42
Background and aims
The possible influence of phosphorus (P) on iron (Fe) deficiency chlorosis in susceptible plants needs elucidation. In this work, we tested the hypothesis that Fe chlorosis can be aggravated at high levels of P in the substrate.Methods
Chickpea, lupin and peanut (in a preliminary experiment), and lupin and sorghum (in a second, factorial experiment) were successively grown on artificial substrates consisting of mixtures of Fe oxide-coated sand (FOCS), calcium carbonate (calcite) sand (CCS) and quartz sand to which phosphate was added at different doses.Results
The proportion of FOCS in the substrate had a significant positive effect on leaf chlorophyll concentration (as estimated via SPAD) in all crops. In the factorial experiment, the SPAD value was negatively affected by the proportion of CCS in the dicot (lupin) but not in the monocot (sorghum). In the preliminary experiment, increasing the P dose generally had little effect on the SPAD of plants grown on the FOCS-rich substrate but a negative effect on those grown on the FOCS-poor substrate. In the factorial experiment, the P dose negatively affected SPAD in both lupin and sorghum.Conclusions
Iron acquisition by the plant is negatively influenced by P probably because the solubility of the Fe oxides decreases with increasing coverage of their surfaces by sorbed phosphate. 相似文献11.
The physiological and nutritional responses of seven different citrus rootstock seedlings to boron deficiency 总被引:2,自引:0,他引:2
Gao F. Zhou Shu A. Peng Yong Z. Liu Qing J. Wei Jia Han Md. Zahidul Islam 《Trees - Structure and Function》2014,28(1):295-307
Key message
Carrizo citrange was the most tolerant citrus rootstock to B-deficiency and some physiological performance could be attributed to the decreased mineral nutrient concentrations caused by B-deficiency.Abstract
Boron (B) is an essential microelement for normal growth and development in vascular plants, and adequate B nutrition is crucial for agricultural production. Although citrus plants are not classified as the most sensitive species to B-deficiency, the occurrence of B-deficiency has been reported in the major citrus producing countries of the world, including the east and south of China. In this study, in order to evaluate the effects of B-deficiency on plant growth, root-morphological traits, B and other nutritional responses of citrus rootstock and to investigate the relationship between this physiological performance and mineral nutrients seven common rootstock seedlings, including Trifoliate orange (TO), Carrizo citrange (CC), Chongyi tangerine (CT), Red tangerine (RT), Cleopatra mandarin (CM), Fragrant citrus (FC), and Sour orange (SO), were treated by B-deficiency (0 mg L?1) or moderate B (0.25 mg L?1). All the seedlings were grown in hydroponics situation with modified 1/2-strength Hoagland’s solution under greenhouse conditions for 10 weeks. The results showed that B-deficiency inhibited the growth and development of all tested citrus rootstocks, but substantial differences were observed among these rootstocks. Different visible symptoms were observed both in the leaf and root. Corking of the leaf veins and leaf yellowing symptoms were observed on all rootstock genotypes except on CC, which exhibited a little discoloration at the end of the experiment. In addition, root growth of the citrus seedlings were also decreased by B-deficiency, but the decreases were more obvious in TO and FC. It was worth noting that B-deficiency inhibited lateral root growth and development more significantly than tap root, but not in lateral root initiation. The different performance of these rootstock genotypes indicated that CC was the most tolerant while TO was the most sensitive to B-deficiency. In addition, under B-deficiency conditions, not only the B concentration, but also the other mineral nutrient concentrations were influenced, especially in Mg, Fe and Mn. This change in nutrient concentrations might partly contribute to the seedlings’ physiological performances under B-deficiency. 相似文献12.
Root porosity, radial oxygen loss and iron plaque on roots of wetland plants in relation to zinc tolerance and accumulation 总被引:2,自引:0,他引:2
Background and aims
Wetland plants have been widely used in constructed wetlands for the clean-up of metal-contaminated waters. This study investigated the relationship between rate of radial oxygen loss (ROL), root porosity, Zn uptake and tolerance, Fe plaque formation in wetland plants.Methods
A hydroponic experiment and a pot trial with Zn-contaminated soil were conducted to apply different Zn level treatments to various emergent wetland plants.Results
Significant differences were found between plants in their root porosities, rates of ROL, Zn uptake and Zn tolerance indices in the hydroponic experiment, and concentrations of Fe and Mn on roots and in the rhizosphere in the pot trial. There were significant positive correlations between root porosities, ROL rates, Zn tolerance, Zn, Fe and Mn concentrations on roots and in the rhizosphere. Wetland plants with higher root porosities and ROL tended to have more Fe plaque, higher Zn concentrations on roots and in their rhizospheres, and were more tolerant of Zn toxicity.Conclusions
Our results suggest that ROL and root porosity play very important roles in Fe plaque formation, Zn uptake and tolerance, and are useful criteria for selecting wetland plants for the phytoremediation of Zn-contaminated waters and soils/sediments. 相似文献13.
14.
15.
Background and aims
Liming is considered normal agricultural practise for remediating soil acidity and improving crop productivity; however recommended lime applications can reduce yield. We tested the hypothesis that elevated xylem sap Ca2+ limited gas exchange of Phaseolus vulgaris L. and Pisum sativum L. plants that exhibited reduced shoot biomass and leaf area when limed.Methods
We used Scholander and whole-plant pressure chamber techniques to collect root and leaf xylem sap, a calcium-specific ion-selective electrode to measure xylem sap Ca2+, infra-red gas analysis to measure gas exchange of limed and unlimed (control) plants, and a detached leaf transpiration bioassay to determine stomatal sensitivity to Ca2+.Results
Liming reduced shoot biomass, leaf area and leaf gas exchange in both species. Root xylem sap Ca2+ concentration was only increased in P. vulgaris and not in P. sativum. Detached leaves of both species required 5 mM Ca2+ supplied to via the transpiration stream to induce stomatal closure, however, maximum in vivo xylem sap Ca2+ concentrations of limed plants was only 1.7 mM and thus not high enough to influence stomata.Conclusion
We conclude that an alternative xylem-borne antitranspirant other than Ca2+ decreases gas exchange of limed plants. 相似文献16.
Nicholas G. Paltridge Lachlan J. Palmer Paul J. Milham Georgia E. Guild James C. R. Stangoulis 《Plant and Soil》2012,361(1-2):251-260
Background and aims
Rice (Oryza sativa L.) and pearl millet (Pennisetum glaucum L.) biofortification breeding programs require accurate and convenient methods to identify nutrient dense genotypes. The aim of this study was to investigate energy-dispersive X-ray fluorescence spectrometry (EDXRF) for the measurement of zinc (Zn) and iron (Fe) concentration in whole grain rice and pearl millet.Methods
Grain samples were obtained from existing biofortification breeding programs. Reference Zn and Fe concentrations obtained by inductively-coupled plasma-optical emission spectroscopy (ICP-OES) were used to calibrate the EDXRF instrument. Calibration was performed with 24 samples and separate calibrations were developed for rice and pearl millet. To validate calibrations, EDXRF analyses were conducted on an additional 40 samples of each species.Results
EDXRF results were highly correlated with ICP-OES values for both Zn and Fe in both species (r2?=?0.79 to 0.98). EDXRF predicted Zn and Fe in rice to within 1.9 and 1.6?mg?kg?1 of ICP-OES values, and Zn and Fe in pearl millet to within 7.6 and 12.5?mg?kg?1 of ICP-OES values, at a 95% confidence level.Conclusion
EDXRF offers a convenient, economical tool for screening Zn and Fe concentration in rice and pearl millet biofortification breeding programs. 相似文献17.
Nicholas G. Paltridge Paul J. Milham J. Ivan Ortiz-Monasterio Govindan Velu Zarina Yasmin Lachlan J. Palmer Georgia E. Guild James C. R. Stangoulis 《Plant and Soil》2012,361(1-2):261-269
Background and aims
Crop biofortification programs require fast, accurate and inexpensive methods of identifying nutrient dense genotypes. This study investigated energy-dispersive X-ray fluorescence spectrometry (EDXRF) for the measurement of zinc (Zn), iron (Fe) and selenium (Se) concentrations in whole grain wheat.Methods
Grain samples were obtained from existing biofortification programs. Reference Zn, Fe and Se concentrations were obtained using inductively coupled plasma optical emission spectrometry (ICP-OES) and/or inductively coupled plasma mass spectrometry (ICP-MS). One set of 25 samples was used to calibrate for Zn (19–60?mg?kg–1) and Fe (26–41?mg?kg–1), with 25 further samples used to calibrate for Se (2–31?mg?kg–1 ). Calibrations were validated using an additional 40–50 wheat samples.Results
EDXRF limits of quantification (LOQ) were estimated as 7, 3 and 2?mg?kg–1 for Zn, Fe, and Se, respectively. EDXRF results were highly correlated with ICP-OES or -MS values. Standard errors of EDXRF predictions were ±2.2?mg Zn kg–1, ±2.6?mg Fe kg–1, and ±1.5?mg Se kg–1.Conclusion
EDXRF offers a fast and economical method for the assessment of Zn, Fe and Se concentration in wheat biofortification programs. 相似文献18.
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19.
A. A. Belimov N. V. Malkov J. V. Puhalsky V. E. Tsyganov K. B. Bodyagina V. I. Safronova K.-J. Dietz I. A. Tikhonovich 《Biologia Plantarum》2018,62(3):543-550
Elucidation of mechanisms underlying plant tolerance to cadmium, a widespread toxic soil pollutant, and accumulation of Cd in plants are urgent tasks. For this purposes, the pea (Pisum sativum L.) mutant SGECdt (obtained by treatment of the laboratory pea line SGE with ethylmethane sulfonate) was reciprocally grafted with the parental line SGE, and four scion/rootstock combinations were obtained: SGE/SGE, SGECdt/SGECdt, SGE/SGECdt, and SGECdt/SGE. They were grown in hydroponics in the presence of 1 μM CdCl2 for 30 d. The SGE and SGECdt scions on the SGECdt rootstock had a higher root and shoot biomass and an elevated root and shoot Cd content compared with the grafts having SGE rootstock. Only the grafts with the SGE rootstock showed chlorosis and roots demonstrating symptoms of Cd toxicity. The content of nutrient elements in roots (Fe, K, Mg, Mn, Na, P, and Zn) was higher in the grafts having the SGECdt rootstock, and three elements, namely Ca, Fe, and Mn, were efficiently transported by the SGECdt root to the shoot of these grafts. The content of other measured elements (K, Mg, Na, P, and Zn) was similar in the root and shoot in all the grafts. Then, the non-grafted plants were grown in the presence of Cd and subjected to deficit or excess concentrations of Ca, Fe, or Mn. Exclusion of these elements from the nutrient solution retained or increased differences between SGE and SGECdt in growth response to Cd toxicity, whereas excess of Ca, Fe, or Mn decreased or eliminated such differences. The obtained results assign a principal role of roots to realizing the increased Cd-tolerance and Cdaccumulation in the SGECdt mutant. Efficient translocation of Ca, Fe, and Mn from roots to shoots appeared to counteract Cd toxicity, although Cd was actively taken up by roots and accumulated in shoots. 相似文献
20.
Rita M. Godinho Carlos Vale Miguel Caetano Luis C. Alves Teresa Pinheiro 《Plant and Soil》2014,376(1-2):129-137