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1.
Rhizobacteria (Pseudomonas sp. SB) assist phytoremediation of oily-sludge-contaminated soil by tall fescue (Testuca arundinacea L.) 总被引:1,自引:0,他引:1
Wuxing Liu Jianying Sun Linlin Ding Yongming Luo Mengfang Chen Caixian Tang 《Plant and Soil》2013,371(1-2):533-542
Background and aims
The objectives of this study were to examine the effect of direct inoculation of seeds with the rhizobacteria Pseudomonas sp. SB on the growth of tall fescue and phytodegradation efficiency in an oily-sludge-contaminated soil.Methods
SB isolated from rhizosphere soil of tall fescue was evaluated for their plant-growth-promoting characters and ability to produce biosurfactant. A pot experiment was conducted to study the effect of inoculation of SB on phytoremediation.Results
SB reduced the surface tension of culture media and produced indole acetic acid, siderophores, and 1-aminocyclopropane-1-carboxylate deaminase. Inoculation of SB increased shoot and root dry weights of tall fescue in oily-sludge-contaminated soil by 28 % and 19 %, respectively. Over 120 days, the content of total petroleum hydrocarbon in soil decreased by 33.9 %, 68.0 %, and 84.5 %, and of polycyclic aromatic hydrocarbons (PAHs) by 32.9 %, 40.9 %, and 46.2 %, respectively, in the no-plant control, tall fescue, and tall fescue + SB treatments. Inoculation of SB also increased the activity and biodiversity of soil microbial communities in the planted treatments.Conclusions
SB could produce biosurfactant and exhibited a number of characters of plant-growth-promoting rhizobacteria. Inoculation of SB to tall fescue led to more effective remediation of oily-sludge-contaminated soils. 相似文献2.
Background and aims
Climate change alters regional plant species distributions, creating new combinations of litter species and soil communities. Biogeographic patterns in microbial communities relate to dissimilarity in microbial community function, meaning novel litters to communities may decompose differently than predicted from their chemical composition. Therefore, the effect of a litter species in the biogeochemical cycle of its current environment may not predict patterns after migration. Under a tree migration sequence we test whether litter quality alone drives litter decomposition, or whether soil communities modify quality effects.Methods
Litter and soils were sampled across an elevation gradient of different overstory species where lower elevation species are predicted to migrate upslope. We use a common garden, laboratory microcosm design (soil community x litter environment) with single and mixed-species litters.Results
We find significant litter quality and microbial community effects (P?<?0.001), explaining 47 % of the variation in decomposition for mixed-litters.Conclusion
Soil community effects are driven by the functional breadth, or historical exposure, of the microbial communities, resulting in lower decomposition of litters inoculated with upslope communities. The litter x soil community interaction suggests that litter decomposition rates in forests of changing tree species composition will be a product of both litter quality and the recipient soil community. 相似文献3.
4.
Manon M. S. Richard Stéphanie Pflieger Mireille Sévignac Vincent Thareau Sophie Blanchet Yupeng Li Scott A. Jackson Valérie Geffroy 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2014,127(7):1653-1666
Key message
The Co - x anthracnose R gene of common bean was fine-mapped into a 58 kb region at one end of chromosome 1, where no canonical NB-LRR-encoding genes are present in G19833 genome sequence.Abstract
Anthracnose, caused by the phytopathogenic fungus Colletotrichum lindemuthianum, is one of the most damaging diseases of common bean, Phaseolus vulgaris. Various resistance (R) genes, named Co-, conferring race-specific resistance to different strains of C. lindemuthianum have been identified. The Andean cultivar JaloEEP558 was reported to carry Co-x on chromosome 1, conferring resistance to the highly virulent strain 100. To fine map Co-x, 181 recombinant inbred lines derived from the cross between JaloEEP558 and BAT93 were genotyped with polymerase chain reaction (PCR)-based markers developed using the genome sequence of the Andean genotype G19833. Analysis of RILs carrying key recombination events positioned Co-x at one end of chromosome 1 to a 58 kb region of the G19833 genome sequence. Annotation of this target region revealed eight genes: three phosphoinositide-specific phospholipases C (PI-PLC), one zinc finger protein and four kinases, suggesting that Co-x is not a classical nucleotide-binding leucine-rich encoding gene. In addition, we identified and characterized the seven members of common bean PI-PLC gene family distributed into two clusters located at the ends of chromosomes 1 and 8. Co-x is not a member of Co-1 allelic series since these two genes are separated by at least 190 kb. Comparative analysis between soybean and common bean revealed that the Co-x syntenic region, located at one end of Glycine max chromosome 18, carries Rhg1, a major QTL contributing to soybean cyst nematode resistance. The PCR-based markers generated in this study should be useful in marker-assisted selection for pyramiding Co-x with other R genes. 相似文献5.
Xiao-lin Zhang Guang-lin Liu Tian-lai Li Ming-fang Qi Mei Mei Xiu-jun Lu 《Trees - Structure and Function》2014,28(3):859-870
Key message
This is the first reported proteomic analysis to study the dormancy breaking of Magnolia sieboldii seeds. Our results provide a fundamental reference for further studies on the regulation of protein expression during seed germination.Abstract
Magnolia sieboldii K. Koch is an ornamental tree. The deep dormancy of its seeds hinders its cultivation for economic purposes. The biochemical basis of the regulation of seed germination remains poorly understood. The present study aimed to identify differentially expressed proteins in germinated seeds of M. sieboldii using polyethylene glycol fractionation. In total, 59 differentially expressed protein spots from two-dimensional gel maps were detected, 33 of which were identified by mass spectrometry. They were assigned to eight functional classes on the basis of their putative biological functions: photosynthesis (3 %), chaperonin/heat shock protein (9 %), protein and amino acid synthesis (9 %), stress/defense (18 %), cytoskeleton structure (3 %), metabolism (18 %), hormone and polyamine (9 %) and storage proteins (31 %). Among the other functions, the effects of plant hormones on seed germination may be one of the most important functions in plant growth. Gibberellins and ethylene positively regulate seed germination. The activities of several hormone-associated proteins possibly influencing seed germination were increased. The characterization of these proteins will be of great help in identifying the molecular mechanism underlying seed germination. 相似文献6.
Sandy Sampaio Videira Michele de Cássia Pereira e Silva Péricles de Souza Galisa Armando Cavalcante Franco Dias Riitta Nissinen Vera Lúcia Baldani Divan Jan Dirk van Elsas José Ivo Baldani Joana Falcão Salles 《Plant and Soil》2013,373(1-2):737-754
Aims
Previous studies have shown that elephant grass is colonized by nitrogen-fixing bacterial species; however, these results were based on culture-dependent methods, an approach that introduces bias due to an incomplete assessment of the microbial community. In this study, we used culture-independent methods to survey the diversity of endophytes and plant-associated bacterial communities in five elephant grass genotypes used in bioenergy production.Methods
The plants of five genotypes of elephant grass were harvested from the experimental area of Embrapa Agrobiologia and divided into stem and root tissues. Total DNA and RNA were extracted from plant tissues and the bacterial communities were analyzed by DGGE and clone library of the 16S rRNA and nifH genes at both the cDNA and DNA levels.Results
Overall, the patterns based on DNA- and RNA-derived DGGE-profiles differed, especially within tissue samples. DNA-based DGGE indicated that both total bacterial and diazotrophic communities associated with roots (rhizoplane?+?endophytes) differed clearly from those obtained from stems (endophytes). These results were confirmed by the phylogenetic analyses of RNA-derived sequences of 16S rRNA (total bacteria; 586 sequences), but not for nifH (186). In fact, rarefaction analyses showed a higher diversity of diazotrophic organisms associated with stems than roots. Based on 16S rRNA sequences, the clone libraries were dominated by sequences affiliated to members of Leptotrix (12.8 %) followed by Burkholderia (9 %) and Bradyrhizobium (6.5 %), while most of the nifH clones were closely related to the genus Bradyrhizobium (26 %).Conclusions
Our results revealed an unexpectedly large diversity of metabolically active bacteria, providing new insights into the bacterial species predominantly found in association with elephant grass. Furthermore, these results can be very useful for the development of new strategies for selection of potential bacteria that effectively contribute to biological nitrogen fixation and enhance the sustainable production of elephant grass as bioenergy crop. 相似文献7.
Background and aims
Dominance of C4 grasses has been proposed as a means of increasing soil organic carbon (SOC) sequestration in restored tallgrass prairies. However, this hypothesis has not been tested on long time scales and under realistic (e.g. N-limited) environmental conditions. We sampled a restoration in southern Illinois 33 years after establishment to determine the effects of varying plant communities on SOC sequestration in the top 50 cm of soil.Methods
SOC, total nitrogen (TN), and the stable isotopic composition of SOC (δ13C) were used to calculate SOC sequestration rates, N storage, and the relative contributions of C3 vs. C4 plant communities as a function of soil depth.Results
While both a forb-dominated and a mixed forb-grass plant community showed positive sequestration rates (0.56?±?0.13 and 0.27?±?0.10 Mg C ha?1 yr?1, respectively), a C4 grass-dominated community showed SOC losses after 33 years of restoration (?0.31?±?0.08 Mg C ha?1 yr?1). Soil δ13C values were significantly more negative for forb-dominated plant communities, increasing the confidence that plant communities were stable over time and an important contributor to differences in SOC stocks among transects.Conclusion
These results suggest that functional diversity may be necessary to sustain sequestration rates on the scale of decades, and that dominance of C4 grasses, favored by frequent burning, may lead to SOC losses over time. 相似文献8.
A. Cruz-Hernández A. Tomasini-Campocosio L. J. Pérez-Flores F. J. Fernández-Perrino M. Gutiérrez-Rojas 《Plant and Soil》2013,362(1-2):261-270
Background and aims
The selective inoculation of specific hydrocarbon-degrading microbes into the plant rhizosphere offers a useful means for remediating hydrocarbon-contaminated soils. The effect of inoculating a seed-borne filamentous fungus (Lewia sp.) on hydrocarbon removal by Festuca arundinacea and its growth was studied on perlite (model soil) and soil, both spiked with hydrocarbons.Methods
A hydrocarbon mixture (1,500 mg kg?1) of two polycyclic aromatic hydrocarbons (PAH), phenanthrene and pyrene, blended with hexadecane (1.0:0.5:0.5 weight) was used. Greenhouse experiments were carried out for 45 days. Inoculated and non-inoculated plants were grown in dark cylindrical glass pots containing perlite or soil.Results
Inoculation with Lewia sp. stimulated (100 %) root growth in spiked perlite. Inoculated plants showed higher phenanthrene removal (100 %) compared to non-inoculated plants in perlite and soil. Pyrene removal by inoculated plants was 37-fold higher than that by non-inoculated plants in perlite; in soil, pyrene removal by inoculated plants (97.9 %) differed significantly from that of non-inoculated plants (91.4 %). Accumulation of pyrene in roots (530.9 mg kg?1 of dry roots) was promoted in perlite.Conclusions
Our results demonstrate that Lewia sp. (endophytic fungus) improved the efficiency of PAH removal by F. arundinacea, on both perlite and soil, stimulating pyrene accumulation in roots. 相似文献9.
Lina Zhen Gaowen Yang Haijun Yang Yongliang Chen Nan Liu Yingjun Zhang 《Plant and Soil》2014,375(1-2):127-136
Background and aims
Nitrogen (N) deposition usually alters plant community structure and reduces plant biodiversity in grasslands. Seedling recruitment is essential for maintaining species richness and determines plant community composition. Arbuscular mycorrhizal fungi (AMF) are widespread symbiotic fungi and could facilitate seedling establishment. Here we conducted an experiment to address whether the influence of AMF on seedling recruitment depends on N addition and plant species.Methods
Leymus chinensis were cultivated for 5 months in the microcosms that were inoculated with or without AMF at five N addition rates. Seeds of three main species (two C3 grasses and one non-N2-fixing forb) of the Eurasian steppe were sown to the 5-month-old microcosms. Seedling establishment was estimated by shoot biomass, N and P contents 7 weeks after seedling germination.Results
AMF promoted seedlings recruitment of two C3 grasses at addition rates above 0.5 g N m?2. In contrast, seedling recruitment of the non-N2-fixing forb was increased by AMF at addition rates below 0.5 g N m?2 but was decreased above 2.5 g N m?2.Conclusions
These results partly explain why N addition favored the dominance of grasses over forbs in perennial grassland communities. Our study indicates that AMF have the potential to influence plant community composition by mediating revegetation in the face of N deposition. 相似文献10.
C. Becerra-Castro Á. Prieto-Fernández P. S. Kidd N. Weyens B. Rodríguez-Garrido M. Touceda-González M. J. Acea J. Vangronsveld 《Plant and Soil》2013,362(1-2):247-260
Background and aims
Microbe-assisted phytoremediation is particularly effective for organic pollutants. The leguminous shrub Cytisus striatus (Hill) Rothm. has been proposed as a candidate species for the rhizoremediation of hexachlorocyclohexane (HCH)-contaminated sites. The aim of this study was to improve the performance of this species using microbial inoculants.Methods
C. striatus was grown in substrates contaminated with 0, 10 and 35 mg HCH kg?1 for 8 weeks. Plants were either not inoculated (NI), or inoculated with the endophyte Rhodococcus erythropolis ET54b and the HCH-degrader Sphingomonas sp. D4 (isolated from a HCH-contaminated soil) on their own or in combination (ET, D4 and ETD4).Results
Inoculation with both bacterial strains (ETD4) resulted in decreased HCH phytotoxicity and improved plant growth. HCH-exposed plants inoculated with ETD4 presented a 120–160 % increase in root, and 140–160 % increase in shoot biomass, and led to a decrease in the activities of enzymes involved in anti-oxidative defence. APOD activity was reduced by up to 37 % in shoot tissues and 25 % in root tissues, and corresponding activities of SOD were reduced by up to 35 % and 30 %. HCH dissipation was enhanced in the presence of C. striatus but no significant effect of microbial inoculants was observed.Conclusions
Inoculating C. striatus with this combination of bacterial strains is a promising approach for the remediation of HCH-contaminated sites. 相似文献11.
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12.
Erik den Boer Ningwen W. Zhang Koen Pelgrom Richard G. F. Visser Rients E. Niks Marieke J. W. Jeuken 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2013,126(12):2995-3007
Key message
Three regions with quantitative resistance to downy mildew of non-host and wild lettuce species, Lactuca saligna , disintegrate into seventeen sub-QTLs with plant-stage-dependent effects, reducing or even promoting the infection.Abstract
Previous studies on the genetic dissection of the complete resistance of wild lettuce, Lactuca saligna, to downy mildew revealed 15 introgression regions that conferred plant stage dependent quantitative resistances (QTLs). Three backcross inbred lines (BILs), carrying an individual 30–50 cM long introgression segment from L. saligna in a cultivated lettuce, L. sativa, background, reduced infection by 60–70 % at young plant stage and by 30–50 % at adult plant stage in field situations. We studied these three quantitative resistances in order to narrow down their mapping interval and determine their number of loci, either single or multiple. We performed recombinant screenings and developed near isogenic lines (NILs) with smaller overlapping L. saligna introgressions (substitution mapping). In segregating introgression line populations, recombination was suppressed up to 17-fold compared to the original L. saligna × L. sativa F 2 population. Recombination suppression depended on the chromosome region and was stronger suppressed at the smallest introgression lengths. Disease evaluation of the NILs revealed that the resistance of all three BILs was not explained by a single locus but by multiple sub-QTLs. The 17 L. saligna-derived sub-QTLs had a smaller and plant stage dependent resistance effect, some segments reducing; others even promoting downy mildew infection. Implications for lettuce breeding are outlined. 相似文献13.
Dörte Randewig Domenica Hamisch Monika Eiblmeier Christian Boedecker Jürgen Kreuzwieser Ralf R. Mendel Robert Hänsch Cornelia Herschbach Heinz Rennenberg 《Trees - Structure and Function》2014,28(2):399-411
Key Message
The critical level for SO 2 susceptibility of Populus × canescens is approximately 1.2 μL L ?1 SO 2 . Both sulfite oxidation and sulfite reduction and assimilation contribute to SO 2 detoxification.Abstract
In the present study, uptake, susceptibility and metabolism of SO2 were analyzed in the deciduous tree species poplar (Populus × canescens). A particular focus was on the significance of sulfite oxidase (SO) for sulfite detoxification, as SO has been characterized as a safety valve for SO2 detoxification in herbaceous plants. For this purpose, poplar plants were exposed to different levels of SO2 (0.65, 0.8, 1.0, 1.2 μL L?1) and were characterized by visible injuries and at the physiological level. Gas exchange parameters (stomatal conductance for water vapor, CO2 assimilation, SO2 uptake) of the shoots were compared with metabolite levels (sulfate, thiols) and enzyme activities [SO, adenosine 5′-phosphosulfate reductase (APR)] in expanding leaves (80–90 % expanded). The critical dosage of SO2 that confers injury to the leaves was 1.2 μL L?1 SO2. The observed increase in sulfur containing compounds (sulfate and thiols) in the expanding leaves strongly correlated with total SO2 uptake of the plant shoot, whereas SO2 uptake rate was strongly correlated with stomatal conductance for water vapor. Furthermore, exposure to high concentration of SO2 revealed channeling of sulfite through assimilatory sulfate reduction that contributes in addition to SO-mediated sulfite oxidation to sulfite detoxification in expanding leaves of this woody plant species. 相似文献14.
15.
Aims
Root elongation tests are sensitive bioassays for testing metal toxicity in nutrient solutions. The metal speciation and, hence, metal exposure conditions are little controlled in the traditional set-up. A resin buffered solution system was developed to overcome this issue.Methods
Barley (Hordeum vulgare L.) root elongation was tested in aerated 140 mL solution batch systems supplied with 3.3 g Dowex resin for two plants. Copper toxicity was measured in presence or absence of the resin (+R/?R) and in presence or absence of a metal complexing ligand (+NTA; nitrilotriacetic acid/?NTA). In addition, the toxicity in the traditional set without resin and with daily solution replacement was included as a reference.Results
Metal desorption from the resin is fast in these systems (k?=?0.82 h?1). Total dissolved Cu roughly halved during 4 days in ?R/?NTA systems due to uptake, while it increased by 30 % in the +R/?NTA, probably due to complexation reactions by root-derived molecules. The toxicity (50 % reduction in root length, EC50) of the initial free Cu2+ was equal in all resin or chelate buffered systems and in the solutions with daily replacement, whereas this threshold was significantly larger in the ?R/?NTA due to Cu2+ uptake and complexation reactions.Conclusion
The resin method is a convenient system for high throughput screening of metal toxicity and avoids uncertainties in metal speciation inherent to chelator buffered systems. Details are given how to prepare the resin to obtain a target metal ion activity. 相似文献16.
Key message
Frequent cloud immersion events result in direct uptake of cloud water and improve plant water potentials during daylight hours in saplings of two dominant cloud forest species.Abstract
In ecosystems with frequent cloud immersion, the influence on plant water balance can be important. While cloud immersion can reduce plant water loss via transpiration, recent advances in methodology have suggested that many species also absorb water directly into leaves (foliar water uptake). The current study examines foliar water uptake and its influence on daily plant water balance in tree species of the endangered spruce–fir forest of the southern Appalachian Mountains, USA. These mountain-top communities are considered relic, boreal forests that may have persisted because of the benefits of frequent cloud immersion. We examined changes in needle water content, xylem water potentials, and stable isotope values in saplings of the two dominant tree species, Abies fraseri and Picea rubens before and after a 24 h period of experimental cloud immersion. Both species exhibited foliar water uptake following immersion, evidenced by substantial changes in stable isotope values of extracted needle water that reflected the composition of the fog water. In addition, total needle water content improved 3.7–6.4 % following experimental submersion and xylem water potentials were significantly greater (up to 0.33 MPa) in cloud-immersed plants over control plants. These results indicate that foliar water uptake may be an adaptive strategy for utilizing cloud water and improving overall tree vigor in these most southerly distributed boreal species. 相似文献17.
Anna Lúcia Mourad Henrique Luvison Gomes da Silva Júlio César Batista Nogueira 《The International Journal of Life Cycle Assessment》2014,19(4):968-976
Purpose
Many companies around the world have been challenged to make their products in a more sustainable way in the last decade in order to minimize their environmental impacts. Klabin, the largest producer, exporter, and recycler of paper in Brazil, has made great efforts to exchange old for new and more efficient equipment to produce cellulose packaging materials. The objective of this study was to measure the benefits of modernization of its plant located in the southern region of the country for manufacturing carrier board/folding box board (CB/FBB) and kraftliner paper (KP).Methods
The goal established was analyzed through a cradle-to-gate life cycle assessment methodology.Results and discussion
The modernization carried out has led to several improvements such as the reductions measured by the functional units of 1,000 kg of CB/FBB and 1,000 kg of KP, respectively, of energy consumption (21 and 3 %), water (8.5 % for CB/FBB only), wood (6.6 and 7.2 %), and land use (6.9 and 7.1 %). The environmental impact categories (according to CML 2001) that have suffered greater reductions are human toxicity (68 and 69 %), abiotic depletion (59 and 28 %), and global warming potential (51 and 9 %) for the same reference units.Conclusions
The results achieved clearly show the importance of renewing industrial plant in order to achieve better environmental performance and also provide a historical inventory perspective for the company to establish future targets for improvement. 相似文献18.
Rasha Kalih Hans Peter Maurer Bernd Hackauf Thomas Miedaner 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2014,127(7):1527-1536
Key message
The rye-derived dwarfing gene Ddw1 on chromosome 5R acts in triticale in considerably reducing plant height, increasing FHB severity and delaying heading stage.Abstract
Triticale, an amphiploid hybrid between durum wheat and rye, is an European cereal mainly grown in Germany, France, Poland, and Belarus for feeding purposes. Dwarfing genes might further improve the genetic potential of triticale concerning lodging resistance and yield. However, they might have pleiotropic effects on other, agronomically important traits including Fusarium head blight. Therefore, we analyzed a population of 199 doubled haploid (DH) lines of the cross HeTi117-06 × Pigmej for plant height, heading stage, and FHB severity across 2 locations and 2 years. The most prominent QTL was detected on chromosome 5R explaining 48, 77, and 71 % of genotypic variation for FHB severity, plant height, and heading stage, respectively. The frequency of recovery in cross validation was ≥90 % for all three traits. Because the markers that detect dwarfing gene Ddw1 in rye are also in our population the most closely linked markers, we assume that this major QTL resembles Ddw1. For FHB severity two, for plant height three, and for heading stage five additional QTL were detected. Caused by the considerable genetic variation for heading stage and FHB severity within the progeny with the dwarfing allele, short-strawed, early heading and FHB-resistant lines can be developed when population size is large enough. 相似文献19.
Purple-leaved Ficus lyrata plants produced by overexpressing a grapevine VvMybA1 gene 总被引:1,自引:0,他引:1
Jietang Zhao Zhijian T. Li Juan Chen Richard J. Henny Dennis J. Gray Jianjun Chen 《Plant cell reports》2013,32(11):1783-1793