共查询到20条相似文献,搜索用时 31 毫秒
1.
Dechao Duan Cheng Peng Chen Xu Mingge Yu Lijuan Sun Natasha Worden Jiyan Shi Tiandou Hu 《Plant and Soil》2014,382(1-2):103-115
Background and aims
Metal species in rhizosphere soil profoundly influence their mobility and phytoavailability. Clarifying the speciation transformation of heavy metals helps understand their translocation and accumulation in plants.Methods
Single extraction, selective sequential extraction (SSE) and X-ray absorption near-edge structure (XANES) spectroscopy were employed to investigate the speciation transformation of lead (Pb) and its influence on metal accumulation in tea plants after the addition of tea polyphenols (TPs).Results
Pb content was decreased in young leaves and stems, whereas increased in roots, after TPs were amended to soil. Both SSE and XANES analysis suggested bioavailable Pb was transformed to organically bound Pb after the addition of TPs. The increased percentage of organically bound Pb might be fixed in the cell wall of plant root through a ternary complex formed between the Pb-organic matter complex and cell wall components. Therefore, Pb translocation from roots to young tissues was decreased.Conclusions
Pb phytoavailability change was driven by its speciation transformation after the addition of TPs. Combined SSE and XANES spectroscopy represent powerful tools to study metal speciation transformation in plant and soil systems. 相似文献2.
Catherine E. Stewart 《Plant and Soil》2012,351(1-2):31-46
Background
Ferns are an important plant group, and older phylogenies of non-polypod ferns contain relatively high concentrations of aliphatic leaf waxes, lignins, and tannins that could contribute to soil organic matter (SOM) biochemistry and stability.Methods
Pyrolysis gas-chromatography mass-spectrometry (py-GC/MS) analyzes biochemical fragments which can be related to lignin, polysaccharide, lipid, nitrogen (N)-bearing, non-lignin aromatics, and phenol source compounds. Thermochemolysis using tetramethylammonium hydroxide (TMAH) combined with py-GC/MS improves detection of lignin, cutin, and suberin-derived compounds. To examine the advantages and disadvantages of both methods for characterizing plant and soil biochemistry, we characterized non-polypod and polypod fern and angiosperm live tissues, roots and soils from the Kohala Mountains, Hawaii.Results
Py-GC/MS provided a broad biochemical overview of compound groups including lignin, polysaccharide, lipid, N-bearing, non-lignin aromatics and phenol groups while TMAH-py-GC/MS detailed lignin units and fatty acids at the expense of the other categories. TMAH-py-GC/MS provided more detailed data on lignin, cutin, suberin and tannin-derived compounds. Both methods detected differences in lignin units between species, although p-coumaric and ferulic acids, predominantly found in ferns, were only observed with TMAH-py-GC/MS.Conclusions
Both py-GC/MS and TMAH-py-GC/MS are methods to detect compound-specific plant biomarkers, but are most useful when combined for their complimentary results. 相似文献3.
David Solance Smith Jennifer A. Schweitzer Philip Turk Joseph K. Bailey Stephen C. Hart Stephen M. Shuster Thomas G. Whitham 《Plant and Soil》2012,352(1-2):243-251
Background and aims
Soils can act as agents of natural selection, causing differential fitness among genotypes and/or families of the same plant species, especially when soils have extreme physical or chemical properties. More subtle changes in soils, such as variation in microbial communities, may also act as agents of selection. We hypothesized that variation in soil properties within a single river drainage can be a selective gradient, driving local adaptation in plants.Methods
Using seeds collected from individual genotypes of Populus angustifolia James and soils collected from underneath the same trees, we use a reciprocal transplant design to test whether seedlings would be locally adapted to their parental soil type.Results
We found three patterns: 1. Soils from beneath individual genotypes varied in pH, soil texture, nutrient content, microbial biomass and the physiological status of microorganisms. 2. Seedlings grown in local soils experienced 2.5-fold greater survival than seedlings planted in non-local soils. 3. Using a composite of height, number of leaves and leaf area to measure plant growth, seedlings grew ~17.5% larger in their local soil than in non-local soil.Conclusions
These data support the hypothesis that variation in soils across subtle gradients can act as an important selective agent, causing differential fitness and local adaptation in plants. 相似文献4.
Background and aims
Nanoscale zero-valent iron (nZVI) application is a promising technology for degradation of chlorinated contaminants in soil. Plants also play an important role in soil remediation and nZVI should not adversely affect plants growing on treated soils. Large amounts of DDT are still found in certain soils and means to remediate these soils are limited. Our aims were to investigate the effect of nZVI on DDT degradation and evaluate possible negative effects of nZVI on plants.Methods
Columns with spiked (20 mg DDT kg?1) soil were percolated with nZVI (1 g nZVI L?1) and leached with five pore volumes of water to assess leaching of nZVI and residual toxicity of leachates and soil to plants using seed germination and plant growth tests (barley, flax).Results
Addition of nZVI led to degradation of 45 % of the added DDT. Percolation with water significantly oxidized and transported iron through the columns. The first leachates had negative effects on plant development, but after leaching with 4 pore volumes, neither soil nor leachates affected plant negatively.Conclusions
nZVI is efficient for degradation of DDT and adverse effects of nZVI on plants seem ephemeral and are alleviated after oxidation mediated by percolating water. 相似文献5.
Background and aims
Soil drying leads to the generation of chemical signals in plants that regulate water use via control of the stomatal aperture. The aim of our work was to identify the presence and identity of potential chemical signals, their dynamics, and their relationship with transpiration rate during soil drying in hop (Humulus lupulus (L.)) plants.Methods
We used pressure chamber technique for measurement of shoot water potential and collection of shoot xylem sap. We analyzed concentrations of abscisic acid (ABA), nitrate, phosphate, sulphate and malate in sap and also the rate of whole plant transpiration.Results
Transpiration rate decreased prior to changes in shoot water potential. The concentration of ABA in xylem sap continuously increased from early to later stages of water stress, whereas in leaves it increased only at later stages. Shoot sap pH increased simultaneously with the decrease of transpiration rate. Xylem sap alkalization was in some cases accompanied by a decrease in nitrate concentration and an increase in malate concentration. Concentration of sulphate increased in xylem sap during drying and sulphate in combination with a higher ABA concentration enhanced stomatal closure.Conclusions
Several early chemical signals appear in sap of hop plants during soil drying and their impact on transpiration may vary according to the stage of soil drying. 相似文献6.
Physiological and genetic characterization of rice nitrogen fixer PGPR isolated from rhizosphere soils of different crops 总被引:1,自引:0,他引:1
Safiullah Habibi Salem Djedidi Kunlayakorn Prongjunthuek Md Firoz Mortuza Naoko Ohkama-Ohtsu Hitoshi Sekimoto Tadashi Yokoyoma 《Plant and Soil》2014,379(1-2):51-66
Aims
We aimed to identify plant growth-promoting rhizobacteria that could be used to develop a biofertilizer for rice.Methods
To obtain plant growth-promoting rhizobacteria, rhizosphere soils from different crops (rice, wheat, oats, crabgrass, maize, ryegrass, and sweet potato) were inoculated to rice plants. In total, 166 different bacteria were isolated and their plant growth-promoting traits were evaluated in terms of colony morphology, indole-3-acetic acid production, acetylene reduction activity, and phosphate solubilization activity. Moreover, genetic analysis was carried out to evaluate their phylogenetic relationships based on 16S rRNA sequence data.Results
Strains of Bacillus altitudinis, Pseudomonas monteilii, and Pseudomonas mandelii formed associations with rice plants and fixed nitrogen. A strain of Rhizobium daejeonense showed nitrogen fixation activity in an in vitro assay and in vivo. Strains of B. altitudinis and R. daejeonense derived from rice rhizosphere soil, strains of P. monteilii and Enterobacter cloacae derived from wheat rhizosphere soil, and a strain of Bacillus pumilus derived from maize rhizosphere soil significantly promoted rice plant growth.Conclusions
These methods are effective to identify candidate species that could be developed as biofertilizers for target crops. 相似文献7.
Dynamics of plant metal uptake and metal changes in whole soil and soil particle fractions during repeated phytoextraction 总被引:2,自引:0,他引:2
Aims
Phytoextration of metal polluted soils using hyperaccumulators is a promising technology but requires long term successive cropping. This study investigated the dynamics of plant metal uptake and changes in soil metals over a long remediation time.Methods
A soil slightly polluted with metals (S1) was mixed with highly polluted soil (S4) to give two intermediate pollution levels (S2, S3). The four resulting soils were repeatedly phyto-extracted using nine successive crops of Cd/Zn-hyperaccumulator Sedum plumbizincicola over a period of 4 years.Results
Shoot Cd concentration decreased with harvest time in all soils but shoot Zn declined in S1 only. Similar shoot Zn concentrations were found in S2, S3 and S4 although these soils differed markedly in metal availability, and their available metals decreased during phytoextraction. A possible explanation is that plant active acquisition ability served to maintain plant metal uptake. Plant uptake resulted in the largest decrease in the acid-soluble metal fraction followed by reducible metals. Oxidisable and residual fractions were less available to plants. The coarse soil particle fractions made the major contribution to metal decline overall than the fine fractions.Conclusion
Sedum plumbizincicola maintained long term metal uptake and the coarse soil particles played the most important role in phytoextraction. 相似文献8.
Background and Aims
Evidence shows that plants modify their microbial environment leading to the “crop rotation effect”, but little is known about the changes in rhizobacterial community structure and functionality associated with beneficial rotation effects.Methods
Polymerase chain reaction (PCR) and 454 GS FLX amplicon pyrosequencing were used to describe the composition of the rhizobacterial community evolving under the influence of pea, a growth promoting rotation crop, and the influence of three genotypes of chickpea, a plant known as an inferior rotation crop. The growth promoting properties of these rhizobacterial communities were tested on wheat in greenhouse assays.Results
The rhizobacterial communities selected by pea and the chickpea CDC Luna in 2008, a wet year, promoted durum wheat growth, but those selected by CDC Vanguard or CDC Frontier had no growth-promoting effect. In 2009, a dry year, the influence of plants was mitigated, indicated that moisture availability is a major driver of soil bacterial community dynamics.Conclusion
The effect of pulse crops on soil biological quality varies with the crop species and genotypes, and certain chickpea genotypes may induce positive rotation effects on wheat. The strength of a rotation effect on soil biological quality is modulated by the abundance of precipitation. 相似文献9.
Jan Schuerings Carl Beierkuhnlein Kerstin Grant Anke Jentsch Andrey Malyshev Josep Peñuelas Jordi Sardans Juergen Kreyling 《Plant and Soil》2013,371(1-2):559-572
Background and aims
Intermittently frozen ground in winter is expected to disappear over large areas in the temperate zone due to ongoing climate warming. The lack of soil frost influences plant soil interactions and needs to be studied in more detail.Methods
Winter soil frost was avoided by belowground heating wires in a field experiment over two subsequent winters in a temperate grassland. Soil respiration, soil nitrogen availability and plant performance (aboveground biomass, root length at two depth levels, greenness, nutrient content) were compared between “no-frost” and reference plots which underwent repeated freeze-thaw cycles in both winters.Results
Soil respiration increased in the “no-frost” treatment during the warming phase (+291 %). N-availability in the upper 10 cm of the soil profile was not affected, possibly due to increased plant N accumulation during winter (+163 %), increased plant N concentration (+18 %) and increased biomass production (+31.5 %) in the growing season. Translocation of roots into deeper soil layers without changes in total root length in response to the “no-frost” treatment, however, may be a sign of nutrient leaching.Conclusions
The cumulative effect on carbon cycling due to warmer soils therefore depends on the balance between increased winter carbon loss due to higher soil biotic activity and enhanced plant productivity with higher nutrient accumulation in the growing season. 相似文献10.
Aims
This study aimed to determine whether white lupin adaptation to moderately calcareous soils could be enhanced by lime-tolerant plants and Bradyrhizobium strains.Methods
Fourteen landraces from Italy, Morocco and Egypt and some cultivars were grown in moderate-lime (ML) and low-lime (LL) soil with each of two inoculants, one commercial and one including three Bradyrhizobium strains well-nodulating under ML soil (isolated from other lupin species). Grain yield and above-ground biomass were assessed in large artificial environments that mimicked field conditions. Shoot, root and nodulation traits at onset of flowering were studied in a pot experiment.Results
ML soil severely reduced plant yield, growth and nodulation but increased the harvest index relative to LL. Top-yielding genotypes for grain yield displayed significant rank inversion across soil types (P < 0.05). Lime-tolerant genotypes reduced their nodulation in ML soil less than limesusceptible ones. Some landraces outperformed the reference lime-tolerant cultivar Giza 1 in ML soil. One Italian landrace had a lime-tolerant response across agricultural locations. The Moroccan inoculant provided greater nodulation, more shoot residues but similar grain yield in ML soil, and less grain and shoot residues in LL soil, compared with the commercial inoculant.Conclusions
Lupin adaptation to ML soil can be improved mainly through selection of lime-tolerant plants. 相似文献11.
Uptake of zinc and phosphorus by plants is affected by zinc fertiliser material and arbuscular mycorrhizas 总被引:2,自引:0,他引:2
Stephanie J. Watts-Williams Terence W. Turney Antonio F. Patti Timothy R. Cavagnaro 《Plant and Soil》2014,376(1-2):165-175
Background and Aims
Water solubility of zinc (Zn) fertilisers affects their plant availability. Further, simultaneous application of Zn and phosphorus (P) fertiliser can have antagonistic effects on plant Zn uptake. Arbuscular mycorrhizas (AM) can improve plant Zn and P uptake. We conducted a glasshouse experiment to test the effect of different Zn fertiliser materials, in conjunction with P fertiliser application, and colonisation by AM, on plant nutrition and biomass.Methods
We grew a mycorrhiza-defective tomato genotype (rmc) and its mycorrhizal wild-type progenitor (76R) in soil with six different Zn fertilisers ranging in water solubility (Zn sulphate, Zn oxide, Zn oxide (nano), Zn phosphate, Zn carbonate, Zn phosphate carbonate), and supplemental P. We measured plant biomass, Zn and P contents, mycorrhizal colonisation and water use efficiency.Results
Whereas water solubility of the Zn fertilisers was not correlated with plant biomass or Zn uptake, plant Zn and P contents differed among Zn fertiliser treatments. Plant Zn and P uptake was enhanced when supplied as Zn phosphate carbonate. Mycorrhizal plants took up more P than non-mycorrhizal plants; the reverse was true for Zn.Conclusions
Zinc fertiliser composition and AM have a profound effect on plant Zn and P uptake. 相似文献12.
13.
Utilizing pyrene-degrading endophytic bacteria to reduce the risk of plant pyrene contamination 总被引:5,自引:0,他引:5
Aims
Endophytic bacteria are ubiquitous in plants, but little information is available on the influence of endophytic bacteria on the uptake and metabolism of PAH by plants. Thus, we seek to investigate whether the colonization of a target plant by a PAH-degrading endophytic bacterium would improve the PAH metabolism of the plant and reduce the risk of plant PAH contamination.Methods
A pyrene-degrading endophyte was isolated from PAH-contaminated plants using enrichment culture. After root inoculation with the isolated bacterium, greenhouse container experiments were conducted. Pyrene residues in soil and plant samples were analyzed by HPLC.Results
A pyrene-degrading endophytic bacterium, Staphylococcus sp. BJ06, was isolated from Alopecurus aequalis and could degrade 56.0 % of pyrene (50 mg?·?L?1) within 15 days. BJ06 grew and degraded pyrene efficiently under environmental conditions. The bacterium significantly promoted ryegrass growth and pyrene removal from contaminated soil in container experiments. The pyrene concentrations in ryegrass roots and shoots in endophyte-inoculated planted soil were reduced by 31.01 % and 44.22 %, respectively, compared with endophyte-free planted soil.Conclusions
We have provided new perspectives on the regulation and control of plant uptake of organic contaminants with endophytic bacteria. The results of this study will be valuable to risk assessments of plant PAH contamination. 相似文献14.
Stef Bokhorst David A. Wardle Marie-Charlotte Nilsson Michael J. Gundale 《Plant and Soil》2014,379(1-2):121-133
Aims
Plant species and functional groups are known to drive the community of belowground invertebrates but whether their effects are consistent across environmental gradients is less well understood. We aimed to determine if plant effects on belowground communities are consistent across a successional gradient in boreal forests of northern Sweden.Methods
We performed two plant removal experiments across ten stands that form a 364-year post-fire boreal forest chronosequence. Through the removal of plant functional groups (mosses or dwarf shrubs) and of individual species of dwarf shrubs, we aimed to determine if the effects of functional groups and species on the soil micro-arthropod community composition varied across this chronosequence.Results
Removal of mosses had a strong negative impact on the abundance and diversity of Collembola and Acari and this effect was consistent across the chronosequence. Only specific Oribatid families declined following dwarf-shrub species removals, with some of these responses being limited to old forest stands.Conclusions
Our results show that the impacts of plants on micro-arthropods is consistent across sites that vary considerably in their stage of post-fire ecosystem development, despite these stages differing greatly in plant productivity, fertility, humus accumulation and moss development. In addition, mosses are a much stronger driver of the micro-arthropod community than vascular plants. 相似文献15.
Aims
We investigated how rhizosphere factors (total rhizosphere, roots, arbuscular mycorrhizal fungal hyphae [AMF], and soil solution) and water availability affect interactions between neighboring Medicago sativa plants.Methods
A three-compartment mesocosm was used to test the effects of rhizosphere factors on plant–plant interactions. A relative interaction index (RII) was calculated to indicate whether effects of neighbor plant on target plant were positive or negative (facilitative or competitive). Isotope tracers were used to test whether AMF hyphae mediated competition for nitrogen (N) between target and neighbor plants.Results
The effects of rhizosphere factors on the interactions between neighboring M. sativa plants depended on water availability. The effects of total rhizosphere shifted RII from negative to positive as water availability increased. Interaction with the roots and rhizosphere soil solution of neighbor plants shifted RII from negative to positive as water availability increased but the opposite was true for AMF hyphae. AMF hyphae helped neighbor plants compete for 15N when water was available but not when water was limiting.Conclusions
The effect of total rhizosphere on plant–plant interaction of M. sativa shifted from competitive to facilitative as water availability increased. Competition was reduced by neighboring soil solution and roots but was increased by AMF hyphae. 相似文献16.
Soil microbial biomass and the fate of phosphorus during long-term ecosystem development 总被引:2,自引:0,他引:2
Benjamin L. Turner Hans Lambers Leo M. Condron Michael D. Cramer Jonathan R. Leake Alan E. Richardson Sally E. Smith 《Plant and Soil》2013,367(1-2):225-234
Background
Soil phosphorus availability declines during long-term ecosystem development on stable land surfaces due to a gradual loss of phosphorus in runoff and transformation of primary mineral phosphate into secondary minerals and organic compounds. These changes have been linked to a reduction in plant biomass as ecosystems age, but the implications for belowground organisms remain unknown.Methods
We constructed a phosphorus budget for the well-studied 120,000 year temperate rainforest chronosequence at Franz Josef, New Zealand. The budget included the amounts of phosphorus in plant biomass, soil microbial biomass, and other soil pools.Results
Soil microbes contained 68–78 % of the total biomass phosphorus (i.e. plant plus microbial) for the majority of the 120,000 year chronosequence. In contrast, plant phosphorus was a relatively small pool that occurred predominantly in wood. This points to the central role of the microbial biomass in determining phosphorus availability as ecosystems mature, yet also indicates the likelihood of strong competition between plants and saprotrophic microbes for soil phosphorus.Conclusions
This novel perspective on terrestrial biogeochemistry challenges our understanding of phosphorus cycling by identifying soil microbes as the major biological phosphorus pool during long-term ecosystem development. 相似文献17.
Atefeh Ramezanian A. Sigrun Dahlin Colin D. Campbell Stephen Hillier Birgitta Mannerstedt-Fogelfors Ingrid Öborn 《Plant and Soil》2013,367(1-2):419-436
Background and Aims
Rising costs and pressure on supplies of commercial mineral fertilizers and increasing markets for organically produced foods and feeds have led to a growing interest in soil amendments to supply plant nutrients. Rockdust is a by-product of quarrying and its effectiveness to supply plants with nutrients has been a contested issue and there have been no assessments of its effect on soil biota other than plants. The aim of this study was to assess the effect of a commercially-available volcanic rockdust application on crop growth and element concentrations for a wide range of macro and microelements and the response of soil microbial communities to rockdust due to the potential alteration in soil mineralogy.Methods
A three-year controlled outdoor-growing experiment was conducted on three different soil types with two wheat cultivars in the first year following rockdust application and with forage species in the third year.Results
Our results show that the tested rockdust had no positive or negative effect on plant growth or nutrient composition. In addition, the microbial response to added substrates, a sensitive measure of changes in soil environment, were unaltered by the rockdust.Conclusions
As the rockdust had no nutrient or toxic effect it can probably be considered as an inert material which at least causes no harm but equally has no demonstrable ecological or agricultural benefit. 相似文献18.
Arbuscular mycorrhizas and their role in plant growth, nitrogen interception and soil gas efflux in an organic production system 总被引:2,自引:0,他引:2
Background and aims
Roots and mycorrhizas play an important role in not only plant nutrient acquisition, but also ecosystem nutrient cycling.Methods
A field experiment was undertaken in which the role of arbuscular mycorrhizas (AM) in the growth and nutrient acquisition of tomato plants was investigated. A mycorrhiza defective mutant of tomato (Solanum lycopersicum L.) (named rmc) and its mycorrhizal wild type progenitor (named 76R) were used to control for the formation of AM. The role of roots and AM in soil N cycling was studied by injecting a 15N-labelled nitrate solution into surface soil at different distances from the 76R and rmc genotypes of tomato, or in plant free soil. The impacts of mycorrhizal and non-mycorrhizal root systems on soil greenhouse gas (CO2 and 14+15N2O and 15N2O) emissions, relative to root free soils, were also studied.Results
The formation of AM significantly enhanced plant growth and nutrient acquisition, including interception of recently applied NO 3 ? . Whereas roots caused a small but significant decrease in 15N2O emissions from soils at 23?h after labeling, compared to the root-free treatment, arbuscular mycorrhizal fungi (AMF) had little effect on N2O emissions. In contrast soil CO2 emissions were higher in plots containing mycorrhizal root systems, where root biomass was also greater.Conclusions
Taken together, these data indicate that roots and AMF have an important role to play in plant nutrient acquisition and ecosystem N cycling. 相似文献19.
Akula Nookaraju Shashank K. Pandey Takeshi Fujino Ju Young Kim Mi Chung Suh Chandrashekhar P. Joshi 《Plant cell reports》2014,33(7):1041-1052
Key message
We report a novel approach for enhanced accumulation of fatty acids and triacylglycerols for utilization as biodiesel in transgenic tobacco stems through xylem-specific expression of Arabidopsis DGAT1 and LEC2 genes.Abstract
The use of plant biomass for production of bioethanol and biodiesel has an enormous potential to revolutionize the global bioenergy outlook. Several studies have recently been initiated to genetically engineer oil production in seeds of crop plants to improve biodiesel production. However, the “food versus fuel” issues have also sparked some studies for enhanced accumulation of oils in vegetative tissues like leaves. But in the case of bioenergy crops, use of woody stems is more practical than leaves. Here, we report the enhanced accumulation of fatty acids (FAs) and triacylglycerols (TAGs) in stems of transgenic tobacco plants expressing Arabidopsis diacylglycerol acyltransferase 1 (DGAT1) and LEAFY COTYLEDON2 (LEC2) genes under a developing xylem-specific cellulose synthase promoter from aspen trees. The transgenic tobacco plants accumulated significantly higher amounts of FAs in their stems. On an average, DGAT1 and LEC2 overexpression showed a 63 and 80 % increase in total FA production in mature stems of transgenic plants over that of controls, respectively. In addition, selected DGAT1 and LEC2 overexpression lines showed enhanced levels of TAGs in stems with higher accumulation of 16:0, 18:2 and 18:3 TAGs. In LEC2 lines, the relative mRNA levels of the downstream genes encoding plastidic proteins involved in FA synthesis and accumulation were also elevated. Thus, here, we provide a proof of concept for our approach of enhancing total energy yield per plant through accumulation of higher levels of FAs in transgenic stems for biodiesel production. 相似文献20.