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Sample records for aboveground plant tissues

  1. Studies on the sources of benzo[a]pyrene in grain and aboveground tissues of rice plants.

    PubMed

    Li, Peijun; Li, Xiaojun; Stagnitti, Frank; Zhang, Hairong; Lin, Xin; Zang, Shuyan; Zhuo, Junchen; Xiong, Xianzhe

    2009-02-15

    Rice plant pot experiments designed to identify benzo[a]pyrene (B[a]P) sources in plant tissues were conducted in an air-quality controlled greenhouse built to prevent contamination from B[a]P air pollution. Results from quartz sand cultures with control and 50, 100 and 500 microgkg(-1) of B[a]P treatments were compared with those from outdoor field experiments, in which rice plants were exposed to polluted air in the urban area of Shenyang, China. When B[a]P was strictly controlled in both air and quartz sand culture medium, the background values of B[a]P in rice plant tissues were uniformly very low. There was no significant difference of B[a]P contents of rice grain between control and treatments of B[a]P in controlled air quality trials. This indicated that the source of B[a]P in the rice grains is not from any B[a]P in the root culture media. The B[a]P content of rice grain, husk, and stem with leaf sampled from outdoor field was up to 7.33-, 9.21- and 27.10-fold higher than corresponding tissues from air-quality controlled conditions. This indicated that polluted air is the main source of B[a]P in aboveground tissues. Therefore control of B[a]P pollution in ambient air is of prime importance for improving the quality of cereal crops. PMID:18585859

  2. Fungal endophytes in aboveground tissues of desert plants: infrequent in culture, but highly diverse and distinctive symbionts.

    PubMed

    Massimo, Nicholas C; Nandi Devan, M M; Arendt, Kayla R; Wilch, Margaret H; Riddle, Jakob M; Furr, Susan H; Steen, Cole; U'Ren, Jana M; Sandberg, Dustin C; Arnold, A Elizabeth

    2015-07-01

    In hot deserts, plants cope with aridity, high temperatures, and nutrient-poor soils with morphological and biochemical adaptations that encompass intimate microbial symbioses. Whereas the root microbiomes of arid-land plants have received increasing attention, factors influencing assemblages of symbionts in aboveground tissues have not been evaluated for many woody plants that flourish in desert environments. We evaluated the diversity, host affiliations, and distributions of endophytic fungi associated with photosynthetic tissues of desert trees and shrubs, focusing on nonsucculent woody plants in the species-rich Sonoran Desert. To inform our strength of inference, we evaluated the effects of two different nutrient media, incubation temperatures, and collection seasons on the apparent structure of endophyte assemblages. Analysis of >22,000 tissue segments revealed that endophytes were isolated four times more frequently from photosynthetic stems than leaves. Isolation frequency was lower than expected given the latitude of the study region and varied among species a function of sampling site and abiotic factors. However, endophytes were very species-rich and phylogenetically diverse, consistent with less arid sites of a similar latitudinal position. Community composition differed among host species, but not as a function of tissue type, sampling site, sampling month, or exposure. Estimates of abundance, diversity, and composition were not influenced by isolation medium or incubation temperature. Phylogenetic analyses of the most commonly isolated genus (Preussia) revealed multiple evolutionary origins of desert-plant endophytism and little phylogenetic structure with regard to seasonality, tissue preference, or optimal temperatures and nutrients for growth in vitro. Together, these results provide insight into endophytic symbioses in desert-plant communities and can be used to optimize strategies for capturing endophyte biodiversity at regional scales. PMID

  3. Fungal endophytes in above-ground tissues of desert plants: infrequent in culture, but highly diverse and distinctive symbionts

    PubMed Central

    Massimo, Nicholas C.; Nandi Devan, MM; Arendt, Kayla R.; Wilch, Margaret H.; Riddle, Jakob M.; Furr, Susan H.; Steen, Cole; U'Ren, Jana M.; Sandberg, Dustin C.; Arnold, A. Elizabeth

    2015-01-01

    In hot deserts, plants cope with aridity, high temperatures, and nutrient-poor soils with morphological and biochemical adaptations that encompass intimate microbial symbioses. Whereas the root microbiomes of arid-land plants have received increasing attention, factors influencing assemblages of symbionts in above-ground tissues have not been evaluated for many woody plants that flourish in desert environments. We evaluated the diversity, host affiliations, and distributions of endophytic fungi associated with photosynthetic tissues of desert trees and shrubs, focusing on non-succulent woody plants in the species-rich Sonoran Desert. To inform our strength of inference, we evaluated the effects of two different nutrient media, incubation temperatures, and collection seasons on the apparent structure of endophyte assemblages. Analysis of >22,000 tissue segments revealed that endophytes were isolated four times more frequently from photosynthetic stems than leaves. Isolation frequency was lower than expected given the latitude of the study region, and varied among species a function of sampling site and abiotic factors. However, endophytes were very species-rich and phylogenetically diverse, consistent with less-arid sites of a similar latitudinal position. Community composition differed among host species, but not as a function of tissue type, sampling site, sampling month, or exposure. Estimates of abundance, diversity and composition were not influenced by isolation medium or incubation temperature. Phylogenetic analyses of the most commonly isolated genus (Preussia) revealed multiple evolutionary origins of desert-plant endophytism and little phylogenetic structure with regard to seasonality, tissue preference, or optimal temperatures and nutrients for growth in vitro. Together, these results provide insight into endophytic symbioses in desert plant communities, and can be used to optimize strategies for capturing endophyte biodiversity at regional scales. PMID

  4. Understanding cross-communication between aboveground and belowground tissues via transcriptome analysis of a sucking insect whitefly-infested pepper plants.

    PubMed

    Park, Yong-Soon; Ryu, Choong-Min

    2014-01-01

    Plants have developed defensive machinery to protect themselves against herbivore and pathogen attacks. We previously reported that aboveground whitefly (Bemisia tabaci Genn.) infestation elicited induced resistance in leaves and roots and influenced the modification of the rhizosphere microflora. In this study, to obtain molecular evidence supporting these plant fitness strategies against whitefly infestation, we performed a 300 K pepper microarray analysis using leaf and root tissues of pepper (Capsicum annuum L.) applied with whitefly, benzo-(1,2,3)-thiadiazole-7-carbothioic acid S-methyl ester (BTH), and the combination of BTH+whitefly. We defined differentially expressed genes (DEGs) as genes exhibiting more than 2-fold change (1.0 based on log2 values) in expression in leaves and roots in response to each treatment compared to the control. We identified a total of 16,188 DEGs in leaves and roots. Of these, 6685, 6752, and 4045 DEGs from leaf tissue and 6768, 7705, and 7667 DEGs from root tissue were identified in the BTH, BTH+whitefly, and whitefly treatment groups, respectively. The total number of DEGs was approximately two-times higher in roots than in whitefly-infested leaves subjected to whitefly infestation. Among DEGs, whitefly feeding induced salicylic acid and jasmonic acid/ethylene-dependent signaling pathways in leaves and roots. Several transporters and auxin-responsive genes were upregulated in roots, which can explain why biomass increase is facilitated. Using transcriptome analysis, our study provides new insights into the molecular basis of whitefly-mediated intercommunication between aboveground and belowground plant tissues and provides molecular evidence that may explain the alteration of rhizosphere microflora and root biomass by whitefly infestation. PMID:24309116

  5. Plant-mediated links between detritivores and aboveground herbivores

    PubMed Central

    Wurst, Susanne

    2013-01-01

    Most studies on plant-mediated above–belowground interactions focus on soil biota with direct trophic links to plant roots such as root herbivores, pathogens, and symbionts. Detritivorous soil fauna, though ubiquitous and present in high abundances and biomasses in soil, are under-represented in those studies. Understanding of their impact on plants is mainly restricted to growth and nutrient uptake parameters. Detritivores have been shown to affect secondary metabolites and defense gene expression in aboveground parts of plants, with potential impacts on aboveground plant–herbivore interactions. The proposed mechanisms range from nutrient mobilization effects and impacts on soil microorganisms to defense induction by passive or active ingestion of roots. Since their negative effects (disruption or direct feeding of roots) may be counterbalanced by their overall beneficial effects (nutrient mobilization), detritivores may not harm, but rather enable plants to respond to aboveground herbivore attacks in a more efficient way. Both more mechanistic and holistic approaches are needed to better understand the involvement of detritivores in plant-mediated above–belowground interactions and their potential for sustainable agriculture. PMID:24069027

  6. Contribution of aboveground plant respiration to carbon cycling in a Bornean tropical rainforet

    NASA Astrophysics Data System (ADS)

    Katayama, Ayumi; Tanaka, Kenzo; Ichie, Tomoaki; Kume, Tomonori; Matsumoto, Kazuho; Ohashi, Mizue; Kumagai, Tomo'omi

    2014-05-01

    Bornean tropical rainforests have a different characteristic from Amazonian tropical rainforests, that is, larger aboveground biomass caused by higher stand density of large trees. Larger biomass may cause different carbon cycling and allocation pattern. However, there are fewer studies on carbon allocation and each component in Bornean tropical rainforests, especially for aboveground plant respiration, compared to Amazonian forests. In this study, we measured woody tissue respiration and leaf respiration, and estimated those in ecosystem scale in a Bornean tropical rainforest. Then, we examined carbon allocation using the data of soil respiration and aboveground net primary production obtained from our previous studies. Woody tissue respiration rate was positively correlated with diameter at breast height (dbh) and stem growth rate. Using the relationships and biomass data, we estimated woody tissue respiration in ecosystem scale though methods of scaling resulted in different estimates values (4.52 - 9.33 MgC ha-1 yr-1). Woody tissue respiration based on surface area (8.88 MgC ha-1 yr-1) was larger than those in Amazon because of large aboveground biomass (563.0 Mg ha-1). Leaf respiration rate was positively correlated with height. Using the relationship and leaf area density data at each 5-m height, leaf respiration in ecosystem scale was estimated (9.46 MgC ha-1 yr-1), which was similar to those in Amazon because of comparable LAI (5.8 m2 m-2). Gross primary production estimated from biometric measurements (44.81 MgC ha-1 yr-1) was much higher than those in Amazon, and more carbon was allocated to woody tissue respiration and total belowground carbon flux. Large tree with dbh > 60cm accounted for about half of aboveground biomass and aboveground biomass increment. Soil respiration was also related to position of large trees, resulting in high soil respiration rate in this study site. Photosynthesis ability of top canopy for large trees was high and leaves for

  7. Aboveground insect herbivory increases plant competitive asymmetry, while belowground herbivory mitigates the effect

    PubMed Central

    Strengbom, Joachim; Viketoft, Maria; Bommarco, Riccardo

    2016-01-01

    Insect herbivores can shift the composition of a plant community, but the mechanism underlying such shifts remains largely unexplored. A possibility is that insects alter the competitive symmetry between plant species. The effect of herbivory on competition likely depends on whether the plants are subjected to aboveground or belowground herbivory or both, and also depends on soil nitrogen levels. It is unclear how these biotic and abiotic factors interactively affect competition. In a greenhouse experiment, we measured competition between two coexisting grass species that respond differently to nitrogen deposition: Dactylis glomerata L., which is competitively favoured by nitrogen addition, and Festuca rubra L., which is competitively favoured on nitrogen-poor soils. We predicted: (1) that aboveground herbivory would reduce competitive asymmetry at high soil nitrogen by reducing the competitive advantage of D. glomerata; and (2), that belowground herbivory would relax competition at low soil nitrogen, by reducing the competitive advantage of F. rubra. Aboveground herbivory caused a 46% decrease in the competitive ability of F. rubra, and a 23% increase in that of D. glomerata, thus increasing competitive asymmetry, independently of soil nitrogen level. Belowground herbivory did not affect competitive symmetry, but the combined influence of above- and belowground herbivory was weaker than predicted from their individual effects. Belowground herbivory thus mitigated the increased competitive asymmetry caused by aboveground herbivory. D. glomerata remained competitively dominant after the cessation of aboveground herbivory, showing that the influence of herbivory continued beyond the feeding period. We showed that insect herbivory can strongly influence plant competitive interactions. In our experimental plant community, aboveground insect herbivory increased the risk of competitive exclusion of F. rubra. Belowground herbivory appeared to mitigate the influence of

  8. Aboveground insect herbivory increases plant competitive asymmetry, while belowground herbivory mitigates the effect.

    PubMed

    Borgström, Pernilla; Strengbom, Joachim; Viketoft, Maria; Bommarco, Riccardo

    2016-01-01

    Insect herbivores can shift the composition of a plant community, but the mechanism underlying such shifts remains largely unexplored. A possibility is that insects alter the competitive symmetry between plant species. The effect of herbivory on competition likely depends on whether the plants are subjected to aboveground or belowground herbivory or both, and also depends on soil nitrogen levels. It is unclear how these biotic and abiotic factors interactively affect competition. In a greenhouse experiment, we measured competition between two coexisting grass species that respond differently to nitrogen deposition: Dactylis glomerata L., which is competitively favoured by nitrogen addition, and Festuca rubra L., which is competitively favoured on nitrogen-poor soils. We predicted: (1) that aboveground herbivory would reduce competitive asymmetry at high soil nitrogen by reducing the competitive advantage of D. glomerata; and (2), that belowground herbivory would relax competition at low soil nitrogen, by reducing the competitive advantage of F. rubra. Aboveground herbivory caused a 46% decrease in the competitive ability of F. rubra, and a 23% increase in that of D. glomerata, thus increasing competitive asymmetry, independently of soil nitrogen level. Belowground herbivory did not affect competitive symmetry, but the combined influence of above- and belowground herbivory was weaker than predicted from their individual effects. Belowground herbivory thus mitigated the increased competitive asymmetry caused by aboveground herbivory. D. glomerata remained competitively dominant after the cessation of aboveground herbivory, showing that the influence of herbivory continued beyond the feeding period. We showed that insect herbivory can strongly influence plant competitive interactions. In our experimental plant community, aboveground insect herbivory increased the risk of competitive exclusion of F. rubra. Belowground herbivory appeared to mitigate the influence of

  9. Plant genetic variation mediates an indirect ecological effect between belowground earthworms and aboveground aphids

    PubMed Central

    2014-01-01

    Background Interactions between aboveground and belowground terrestrial communities are often mediated by plants, with soil organisms interacting via the roots and aboveground organisms via the shoots and leaves. Many studies now show that plant genetics can drive changes in the structure of both above and belowground communities; however, the role of plant genetic variation in mediating aboveground-belowground interactions is still unclear. We used an earthworm-plant-aphid model system with two aphid species (Aphis fabae and Acyrthosiphon pisum) to test the effect of host-plant (Vicia faba) genetic variation on the indirect interaction between the belowground earthworms (Eisenia veneta) on the aboveground aphid populations. Results Our data shows that host-plant variety mediated an indirect ecological effect of earthworms on generalist black bean aphids (A. fabae), with earthworms increasing aphid growth rate in three plant varieties but decreasing it in another variety. We found no effect of earthworms on the second aphid species, the pea aphid (A. pisum), and no effect of competition between the aphid species. Plant biomass was increased when earthworms were present, and decreased when A. pisum was feeding on the plant (mediated by plant variety). Although A. fabae aphids were influenced by the plants and worms, they did not, in turn, alter plant biomass. Conclusions Previous work has shown inconsistent effects of earthworms on aphids, but we suggest these differences could be explained by plant genetic variation and variation among aphid species. This study demonstrates that the outcome of belowground-aboveground interactions can be mediated by genetic variation in the host-plant, but depends on the identity of the species involved. PMID:25331082

  10. Putative linkages between below- and aboveground mutualisms during alien plant invasions.

    PubMed

    Rodríguez-Echeverría, Susana; Traveset, Anna

    2015-01-01

    Evidence of the fundamental role of below-aboveground links in controlling ecosystem processes is mostly based on studies done with soil herbivores or mutualists and aboveground herbivores. Much less is known about the links between belowground and aboveground mutualisms, which have been studied separately for decades. It has not been until recently that these mutualisms-mycorrhizas and legume-rhizobia on one hand, and pollinators and seed dispersers on the other hand-have been found to influence each other, with potential ecological and evolutionary consequences. Here we review the mechanisms that may link these two-level mutualisms, mostly reported for native plant species, and make predictions about their relevance during alien plant invasions. We propose that alien plants establishing effective mutualisms with belowground microbes might improve their reproductive success through positive interactions between those mutualists and pollinators and seed dispersers. On the other hand, changes in the abundance and diversity of soil mutualists induced by invasion can also interfere with below-aboveground links for native plant species. We conclude that further research on this topic is needed in the field of invasion ecology as it can provide interesting clues on synergistic interactions and invasional meltdowns during alien plant invasions. PMID:26034049

  11. Putative linkages between below- and aboveground mutualisms during alien plant invasions

    PubMed Central

    Rodríguez-Echeverría, Susana; Traveset, Anna

    2015-01-01

    Evidence of the fundamental role of below–aboveground links in controlling ecosystem processes is mostly based on studies done with soil herbivores or mutualists and aboveground herbivores. Much less is known about the links between belowground and aboveground mutualisms, which have been studied separately for decades. It has not been until recently that these mutualisms—mycorrhizas and legume–rhizobia on one hand, and pollinators and seed dispersers on the other hand—have been found to influence each other, with potential ecological and evolutionary consequences. Here we review the mechanisms that may link these two-level mutualisms, mostly reported for native plant species, and make predictions about their relevance during alien plant invasions. We propose that alien plants establishing effective mutualisms with belowground microbes might improve their reproductive success through positive interactions between those mutualists and pollinators and seed dispersers. On the other hand, changes in the abundance and diversity of soil mutualists induced by invasion can also interfere with below–aboveground links for native plant species. We conclude that further research on this topic is needed in the field of invasion ecology as it can provide interesting clues on synergistic interactions and invasional meltdowns during alien plant invasions. PMID:26034049

  12. Facilitation and inhibition: changes in plant nitrogen and secondary metabolites mediate interactions between aboveground and belowground herbivores

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To date, it remains unclear how herbivore-induced changes in plant primary and secondary metabolites impact aboveground and belowground herbivore interactions. Here we report the effects of aboveground (adult) and belowground (larval) feeding by Bikasha collaris on nitrogen and secondary chemicals i...

  13. Plant diversity and functional groups affect Si and Ca pools in aboveground biomass of grassland systems.

    PubMed

    Schaller, Jörg; Roscher, Christiane; Hillebrand, Helmut; Weigelt, Alexandra; Oelmann, Yvonne; Wilcke, Wolfgang; Ebeling, Anne; Weisser, Wolfgang W

    2016-09-01

    Plant diversity is an important driver of nitrogen and phosphorus stocks in aboveground plant biomass of grassland ecosystems, but plant diversity effects on other elements also important for plant growth are less understood. We tested whether plant species richness, functional group richness or the presence/absence of particular plant functional groups influences the Si and Ca concentrations (mmol g(-1)) and stocks (mmol m(-2)) in aboveground plant biomass in a large grassland biodiversity experiment (Jena Experiment). In the experiment including 60 temperate grassland species, plant diversity was manipulated as sown species richness (1, 2, 4, 8, 16) and richness and identity of plant functional groups (1-4; grasses, small herbs, tall herbs, legumes). We found positive species richness effects on Si as well as Ca stocks that were attributable to increased biomass production. The presence of particular functional groups was the most important factor explaining variation in aboveground Si and Ca stocks (mmol m(-2)). Grass presence increased the Si stocks by 140 % and legume presence increased the Ca stock by 230 %. Both the presence of specific plant functional groups and species diversity altered Si and Ca stocks, whereas Si and Ca concentration were affected mostly by the presence of specific plant functional groups. However, we found a negative effect of species diversity on Si and Ca accumulation, by calculating the deviation between mixtures and mixture biomass proportions, but in monoculture concentrations. These changes may in turn affect ecosystem processes such as plant litter decomposition and nutrient cycling in grasslands. PMID:27164912

  14. Temporal variability in aboveground plant biomass decreases as spatial variability increases.

    PubMed

    McGranahan, Devan Allen; Hovick, Torre J; Elmore, R Dwayne; Engle, David M; Fuhlendorf, Samuel D; Winter, Stephen L; Miller, James R; Debinski, Diane M

    2016-03-01

    Ecological theory predicts that diversity decreases variability in ecosystem function. We predict that, at the landscape scale, spatial variability created by a mosaic of contrasting patches that differ in time since disturbance will decrease temporal variability in aboveground plant biomass. Using data from a multi-year study of seven grazed tallgrass prairie landscapes, each experimentally managed for one to eight patches, we show that increased spatial variability driven by spatially patchy fire and herbivory reduces temporal variability in aboveground plant biomass. This pattern is associated with statistical evidence for the portfolio effect and a positive relationship between temporal variability and functional group synchrony as predicted by metacommunity variability theory. As disturbance from fire and grazing interact to create a shifting mosaic of spatially heterogeneous patches within a landscape, temporal variability in aboveground plant biomass can be dampened. These results suggest that spatially heterogeneous disturbance regimes contribute to a portfolio of ecosystem functions provided by biodiversity, including wildlife habitat, fuel, and forage. We discuss how spatial patterns of disturbance drive variability within and among patches. PMID:27197382

  15. Plant systemic induced responses mediate interactions between root parasitic nematodes and aboveground herbivorous insects.

    PubMed

    Wondafrash, Mesfin; Van Dam, Nicole M; Tytgat, Tom O G

    2013-01-01

    Insects and nematodes are the most diverse and abundant groups of multicellular animals feeding on plants on either side of the soil-air interface. Several herbivore-induced responses are systemic, and hence can influence the preference and performance of organisms in other plant organs. Recent studies show that plants mediate interactions between belowground plant parasitic nematodes (PPNs) and aboveground herbivorous insects. Based on the knowledge of plant responses to pathogens, we review the emerging insights on plant systemic responses against root-feeding nematodes and shoot-feeding insects. We discuss the potential mechanisms of plant-mediated indirect interactions between both groups of organisms and point to gaps in our knowledge. Root-feeding nematodes can positively or negatively affect shoot herbivorous insects, and vice versa. The outcomes of the interactions between these spatially separated herbivore communities appear to be influenced by the feeding strategy of the nematodes and the insects, as well as by host plant susceptibility to both herbivores. The potential mechanisms for these interactions include systemic induced plant defense, interference with the translocation and dynamics of locally induced secondary metabolites, and reallocation of plant nutritional reserves. During evolution, PPNs as well as herbivorous insects have acquired effectors that modify plant defense responses and resource allocation patterns to their advantage. However, it is also known that plants under herbivore attack change the allocation of their resources, e.g., for compensatory growth responses, which may affect the performance of other organisms feeding on the plant. Studying the chemical and molecular basis of these interactions will reveal the molecular mechanisms that are involved. Moreover, it will lead to a better understanding of the ecological relevance of aboveground-belowground interactions, as well as support the development of sustainable pest management

  16. Plant Diversity Impacts Decomposition and Herbivory via Changes in Aboveground Arthropods

    PubMed Central

    Ebeling, Anne; Meyer, Sebastian T.; Abbas, Maike; Eisenhauer, Nico; Hillebrand, Helmut; Lange, Markus; Scherber, Christoph; Vogel, Anja; Weigelt, Alexandra; Weisser, Wolfgang W.

    2014-01-01

    Loss of plant diversity influences essential ecosystem processes as aboveground productivity, and can have cascading effects on the arthropod communities in adjacent trophic levels. However, few studies have examined how those changes in arthropod communities can have additional impacts on ecosystem processes caused by them (e.g. pollination, bioturbation, predation, decomposition, herbivory). Therefore, including arthropod effects in predictions of the impact of plant diversity loss on such ecosystem processes is an important but little studied piece of information. In a grassland biodiversity experiment, we addressed this gap by assessing aboveground decomposer and herbivore communities and linking their abundance and diversity to rates of decomposition and herbivory. Path analyses showed that increasing plant diversity led to higher abundance and diversity of decomposing arthropods through higher plant biomass. Higher species richness of decomposers, in turn, enhanced decomposition. Similarly, species-rich plant communities hosted a higher abundance and diversity of herbivores through elevated plant biomass and C:N ratio, leading to higher herbivory rates. Integrating trophic interactions into the study of biodiversity effects is required to understand the multiple pathways by which biodiversity affects ecosystem functioning. PMID:25226237

  17. Estimating aboveground biomass for broadleaf woody plants and young conifers in Sierra Nevada, California forests.

    USGS Publications Warehouse

    McGinnis, Thomas W.; Shook, Christine D.; Keeley, Jon E.

    2010-01-01

    Quantification of biomass is fundamental to a wide range of research and natural resource management goals. An accurate estimation of plant biomass is essential to predict potential fire behavior, calculate carbon sequestration for global climate change research, assess critical wildlife habitat, and so forth. Reliable allometric equations from simple field measurements are necessary for efficient evaluation of plant biomass. However, allometric equations are not available for many common woody plant taxa in the Sierra Nevada. In this report, we present more than 200 regression equations for the Sierra Nevada western slope that relate crown diameter, plant height, crown volume, stem diameter, and both crown diameter and height to the dry weight of foliage, branches, and entire aboveground biomass. Destructive sampling methods resulted in regression equations that accurately predict biomass from one or two simple, nondestructive field measurements. The tables presented here will allow researchers and natural resource managers to easily choose the best equations to fit their biomass assessment needs.

  18. Estimating aboveground biomass for broadleaf woody plants and young conifers in Sierra Nevada, California, forests

    USGS Publications Warehouse

    McGinnis, T.W.; Shook, C.D.; Keeley, J.E.

    2010-01-01

    Quantification of biomass is fundamental to a wide range of research and natural resource management goals. An accurate estimation of plant biomass is essential to predict potential fire behavior, calculate carbon sequestration for global climate change research, assess critical wildlife habitat, and so forth. Reliable allometric equations from simple field measurements are necessary for efficient evaluation of plant biomass. However, allometric equations are not available for many common woody plant taxa in the Sierra Nevada. In this report, we present more than 200 regression equations for the Sierra Nevada western slope that relate crown diameter, plant height, crown volume, stem diameter, and both crown diameter and height to the dry weight of foliage, branches, and entire aboveground biomass. Destructive sampling methods resulted in regression equations that accurately predict biomass from one or two simple, nondestructive field measurements. The tables presented here will allow researchers and natural resource managers to easily choose the best equations to fit their biomass assessment needs.

  19. Below-ground plant-fungus network topology is not congruent with above-ground plant-animal network topology.

    PubMed

    Toju, Hirokazu; Guimarães, Paulo R; Olesen, Jens M; Thompson, John N

    2015-10-01

    In nature, plants and their pollinating and/or seed-dispersing animals form complex interaction networks. The commonly observed pattern of links between specialists and generalists in these networks has been predicted to promote species coexistence. Plants also build highly species-rich mutualistic networks below ground with root-associated fungi, and the structure of these plant-fungus networks may also affect terrestrial community processes. By compiling high-throughput DNA sequencing data sets of the symbiosis of plants and their root-associated fungi from three localities along a latitudinal gradient, we uncovered the entire network architecture of these interactions under contrasting environmental conditions. Each network included more than 30 plant species and hundreds of mycorrhizal and endophytic fungi belonging to diverse phylogenetic groups. The results were consistent with the notion that processes shaping host-plant specialization of fungal species generate a unique linkage pattern that strongly contrasts with the pattern of above-ground plant-partner networks. Specifically, plant-fungus networks lacked a "nested" architecture, which has been considered to promote species coexistence in plant-partner networks. Rather, the below-ground networks had a conspicuous "antinested" topology. Our findings lead to the working hypothesis that terrestrial plant community dynamics are likely determined by the balance between above-ground and below-ground webs of interspecific interactions. PMID:26601279

  20. Plant systemic induced responses mediate interactions between root parasitic nematodes and aboveground herbivorous insects

    PubMed Central

    Wondafrash, Mesfin; Van Dam, Nicole M.; Tytgat, Tom O. G.

    2013-01-01

    Insects and nematodes are the most diverse and abundant groups of multicellular animals feeding on plants on either side of the soil–air interface. Several herbivore-induced responses are systemic, and hence can influence the preference and performance of organisms in other plant organs. Recent studies show that plants mediate interactions between belowground plant parasitic nematodes (PPNs) and aboveground herbivorous insects. Based on the knowledge of plant responses to pathogens, we review the emerging insights on plant systemic responses against root-feeding nematodes and shoot-feeding insects. We discuss the potential mechanisms of plant-mediated indirect interactions between both groups of organisms and point to gaps in our knowledge. Root-feeding nematodes can positively or negatively affect shoot herbivorous insects, and vice versa. The outcomes of the interactions between these spatially separated herbivore communities appear to be influenced by the feeding strategy of the nematodes and the insects, as well as by host plant susceptibility to both herbivores. The potential mechanisms for these interactions include systemic induced plant defense, interference with the translocation and dynamics of locally induced secondary metabolites, and reallocation of plant nutritional reserves. During evolution, PPNs as well as herbivorous insects have acquired effectors that modify plant defense responses and resource allocation patterns to their advantage. However, it is also known that plants under herbivore attack change the allocation of their resources, e.g., for compensatory growth responses, which may affect the performance of other organisms feeding on the plant. Studying the chemical and molecular basis of these interactions will reveal the molecular mechanisms that are involved. Moreover, it will lead to a better understanding of the ecological relevance of aboveground–belowground interactions, as well as support the development of sustainable pest

  1. Estimating aboveground biomass of broadleaved woody plants in the understory of Florida Keys pine forests

    USGS Publications Warehouse

    Sah, J.P.; Ross, M.S.; Koptur, S.; Snyder, J.R.

    2004-01-01

    Species-specific allometric equations that provide estimates of biomass from measured plant attributes are currently unavailable for shrubs common to South Florida pine rocklands, where fire plays an important part in shaping the structure and function of ecosystems. We developed equations to estimate total aboveground biomass and fine fuel of 10 common hardwood species in the shrub layer of pine forests of the lower Florida Keys. Many equations that related biomass categories to crown area and height were significant (p < 0.05), but the form and variables comprising the best model varied among species. We applied the best-fit regression models to structural information from the shrub stratum in 18 plots on Big Pine Key, the most extensive pine forest in the Keys. Estimates based on species-specific equations indicated clearly that total aboveground shrub biomass and shrub fine fuel increased with time since last fire, but the relationships were non-linear. The relative proportion of biomass constituted by the major species also varied with stand age. Estimates based on mixed-species regressions differed slightly from estimates based on species-specific models, but the former could provide useful approximations in similar forests where species-specific regressions are not yet available. ?? 2004 Elsevier B.V. All rights reserved.

  2. Plant-herbivore-carnivore interactions in cotton, Gossypium hirsutum: Linking belowground and aboveground

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We subjected cotton plants to 48 hours of leaf feeding by an insect larvae and 5 weeks of root feeding by a plant parasitic nematode to determine if typical plant tissue defenses and plant chemical volatiles (commonly attractive to predators of the insect larvae) are affected by the presence of both...

  3. The response of aboveground plant productivity to earlier snowmelt and summer warming in an Arctic ecosystem

    NASA Astrophysics Data System (ADS)

    Livensperger, C.; Steltzer, H.; Darrouzet-Nardi, A.; Sullivan, P.; Wallenstein, M. D.; Weintraub, M. N.

    2012-12-01

    Plant communities in the Arctic are undergoing changes in structure and function due to shifts in seasonality from changing winters and summer warming. These changes will impact biogeochemical cycling, surface energy balance, and functioning of vertebrate and invertebrate communities. To examine seasonal controls on aboveground net primary production (ANPP) in a moist acidic tundra ecosystem in northern Alaska, we shifted the growing season by accelerating snowmelt (using radiation absorbing shadecloth) and warming air and soil temperature (using 1 m2 open-top chambers), individually and in combination. After three years, we measured ANPP by harvesting up to 16 individual ramets, tillers and rhizomes for each of 7 plant species, including two deciduous shrubs, two graminoids, two evergreen shrubs and one forb during peak season. Our results show that ANPP per stem summed across the 7 species increased when snow melt occurred earlier. However, standing biomass, excluding current year growth, was also greater. The ratio of ANPP/standing biomass decreased in all treatments compared to the control. ANPP per unit standing biomass summed for the four shrub species decreases due to summer warming alone or in combination with early snowmelt; however early snowmelt alone did not lead to lower ANPP for the shrubs. ANPP per tiller or rhizome summed for the three herbaceous species increased in response to summer warming. Understanding the differential response of plants to changing seasonality will inform predictions of future Arctic plant community structure and function.

  4. Arbuscular mycorrhizal colonization, plant chemistry, and aboveground herbivory on Senecio jacobaea

    NASA Astrophysics Data System (ADS)

    Reidinger, Stefan; Eschen, René; Gange, Alan C.; Finch, Paul; Bezemer, T. Martijn

    2012-01-01

    Arbuscular mycorrhizal fungi (AMF) can affect insect herbivores by changing plant growth and chemistry. However, many factors can influence the symbiotic relationship between plant and fungus, potentially obscuring experimental treatments and ecosystem impacts. In a field experiment, we assessed AMF colonization levels of individual ragwort ( Senecio jacobaea) plants growing in grassland plots that were originally sown with 15 or 4 plant species, or were unsown. We measured the concentrations of carbon, nitrogen and pyrrolizidine alkaloids (PAs), and assessed the presence of aboveground insect herbivores on the sampled plants. Total AMF colonization and colonization by arbuscules was lower in plots sown with 15 species than in plots sown with 4 species and unsown plots. AMF colonization was positively related to the cover of oxeye daisy ( Leucanthemum vulgare) and a positive relationship between colonization by arbuscules and the occurrence of a specialist seed-feeding fly ( Pegohylemyia seneciella) was found. The occurrence of stem-boring, leaf-mining and sap-sucking insects was not affected by AMF colonization. Total PA concentrations were negatively related to colonization levels by vesicles, but did not differ among the sowing treatments. No single factor explained the observed differences in AMF colonization among the sowing treatments or insect herbivore occurrence on S. jacobaea. However, correlations across the treatments suggest that some of the variation was due to the abundance of one plant species, which is known to stimulate AMF colonization of neighbouring plants, while AMF colonization was related to the occurrence of a specialist insect herbivore. Our results thus illustrate that in natural systems, the ecosystem impact of AMF through their influence on the occurrence of specialist insects can be recognised, but they also highlight the confounding effect of neighbouring plant species identity. Hence, our results emphasise the importance of field

  5. Plant Tissue Culture Studies.

    ERIC Educational Resources Information Center

    Smith, Robert Alan

    Plant tissue culture has developed into a valid botanical discipline and is considered a key area of biotechnology, but it has not been a key component of the science curriculum because of the expensive and technical nature of research in this area. This manual presents a number of activities that are relatively easy to prepare and perform. The…

  6. Shifting grassland plant community structure drives positive interactive effects of warming and diversity on aboveground net primary productivity.

    PubMed

    Cowles, Jane M; Wragg, Peter D; Wright, Alexandra J; Powers, Jennifer S; Tilman, David

    2016-02-01

    Ecosystems worldwide are increasingly impacted by multiple drivers of environmental change, including climate warming and loss of biodiversity. We show, using a long-term factorial experiment, that plant diversity loss alters the effects of warming on productivity. Aboveground primary productivity was increased by both high plant diversity and warming, and, in concert, warming (≈1.5 °C average above and belowground warming over the growing season) and diversity caused a greater than additive increase in aboveground productivity. The aboveground warming effects increased over time, particularly at higher levels of diversity, perhaps because of warming-induced increases in legume and C4 bunch grass abundances, and facilitative feedbacks of these species on productivity. Moreover, higher plant diversity was associated with the amelioration of warming-induced environmental conditions. This led to cooler temperatures, decreased vapor pressure deficit, and increased surface soil moisture in higher diversity communities. Root biomass (0-30 cm) was likewise consistently greater at higher plant diversity and was greater with warming in monocultures and at intermediate diversity, but at high diversity warming had no detectable effect. This may be because warming increased the abundance of legumes, which have lower root : shoot ratios than the other types of plants. In addition, legumes increase soil nitrogen (N) supply, which could make N less limiting to other species and potentially decrease their investment in roots. The negative warming × diversity interaction on root mass led to an overall negative interactive effect of these two global change factors on the sum of above and belowground biomass, and thus likely on total plant carbon stores. In total, plant diversity increased the effect of warming on aboveground net productivity and moderated the effect on root mass. These divergent effects suggest that warming and changes in plant diversity are likely to have both

  7. Repressor-mediated tissue-specific gene expression in plants

    DOEpatents

    Meagher, Richard B.; Balish, Rebecca S.; Tehryung, Kim; McKinney, Elizabeth C.

    2009-02-17

    Plant tissue specific gene expression by way of repressor-operator complexes, has enabled outcomes including, without limitation, male sterility and engineered plants having root-specific gene expression of relevant proteins to clean environmental pollutants from soil and water. A mercury hyperaccumulation strategy requires that mercuric ion reductase coding sequence is strongly expressed. The actin promoter vector, A2pot, engineered to contain bacterial lac operator sequences, directed strong expression in all plant vegetative organs and tissues. In contrast, the expression from the A2pot construct was restricted primarily to root tissues when a modified bacterial repressor (LacIn) was coexpressed from the light-regulated rubisco small subunit promoter in above-ground tissues. Also provided are analogous repressor operator complexes for selective expression in other plant tissues, for example, to produce male sterile plants.

  8. Response of Plant Height, Species Richness and Aboveground Biomass to Flooding Gradient along Vegetation Zones in Floodplain Wetlands, Northeast China

    PubMed Central

    Lou, Yanjing; Pan, Yanwen; Gao, Chuanyu; Jiang, Ming; Lu, Xianguo; Xu, Y. Jun

    2016-01-01

    Flooding regime changes resulting from natural and human activity have been projected to affect wetland plant community structures and functions. It is therefore important to conduct investigations across a range of flooding gradients to assess the impact of flooding depth on wetland vegetation. We conducted this study to identify the pattern of plant height, species richness and aboveground biomass variation along the flooding gradient in floodplain wetlands located in Northeast China. We found that the response of dominant species height to the flooding gradient depends on specific species, i.e., a quadratic response for Carex lasiocarpa, a negative correlation for Calamagrostis angustifolia, and no response for Carex appendiculata. Species richness showed an intermediate effect along the vegetation zone from marsh to wet meadow while aboveground biomass increased. When the communities were analysed separately, only the water table depth had significant impact on species richness for two Carex communities and no variable for C. angustifolia community, while height of dominant species influenced aboveground biomass. When the three above-mentioned communities were grouped together, variations in species richness were mainly determined by community type, water table depth and community mean height, while variations in aboveground biomass were driven by community type and the height of dominant species. These findings indicate that if habitat drying of these herbaceous wetlands in this region continues, then two Carex marshes would be replaced gradually by C. angustifolia wet meadow in the near future. This will lead to a reduction in biodiversity and an increase in productivity and carbon budget. Meanwhile, functional traits must be considered, and should be a focus of attention in future studies on the species diversity and ecosystem function in this region. PMID:27097325

  9. Response of Plant Height, Species Richness and Aboveground Biomass to Flooding Gradient along Vegetation Zones in Floodplain Wetlands, Northeast China.

    PubMed

    Lou, Yanjing; Pan, Yanwen; Gao, Chuanyu; Jiang, Ming; Lu, Xianguo; Xu, Y Jun

    2016-01-01

    Flooding regime changes resulting from natural and human activity have been projected to affect wetland plant community structures and functions. It is therefore important to conduct investigations across a range of flooding gradients to assess the impact of flooding depth on wetland vegetation. We conducted this study to identify the pattern of plant height, species richness and aboveground biomass variation along the flooding gradient in floodplain wetlands located in Northeast China. We found that the response of dominant species height to the flooding gradient depends on specific species, i.e., a quadratic response for Carex lasiocarpa, a negative correlation for Calamagrostis angustifolia, and no response for Carex appendiculata. Species richness showed an intermediate effect along the vegetation zone from marsh to wet meadow while aboveground biomass increased. When the communities were analysed separately, only the water table depth had significant impact on species richness for two Carex communities and no variable for C. angustifolia community, while height of dominant species influenced aboveground biomass. When the three above-mentioned communities were grouped together, variations in species richness were mainly determined by community type, water table depth and community mean height, while variations in aboveground biomass were driven by community type and the height of dominant species. These findings indicate that if habitat drying of these herbaceous wetlands in this region continues, then two Carex marshes would be replaced gradually by C. angustifolia wet meadow in the near future. This will lead to a reduction in biodiversity and an increase in productivity and carbon budget. Meanwhile, functional traits must be considered, and should be a focus of attention in future studies on the species diversity and ecosystem function in this region. PMID:27097325

  10. Plant Tissues. Agricultural Lesson Plans.

    ERIC Educational Resources Information Center

    Southern Illinois Univ., Carbondale. Dept. of Agricultural Education and Mechanization.

    This lesson plan is intended for use in conducting classes on plant tissues. Presented first are an attention step and a series of questions and answers designed to convey general information about plant tissues and the effect of water and minerals on them. The following topics are among those discussed: reasons why water is important to plants,…

  11. Facilitation and inhibition: changes in plant nitrogen and secondary metabolites mediate interactions between above-ground and below-ground herbivores.

    PubMed

    Huang, Wei; Siemann, Evan; Yang, Xuefang; Wheeler, Gregory S; Ding, Jianqing

    2013-09-22

    To date, it remains unclear how herbivore-induced changes in plant primary and secondary metabolites impact above-ground and below-ground herbivore interactions. Here, we report effects of above-ground (adult) and below-ground (larval) feeding by Bikasha collaris on nitrogen and secondary chemicals in shoots and roots of Triadica sebifera to explain reciprocal above-ground and below-ground insect interactions. Plants increased root tannins with below-ground herbivory, but above-ground herbivory prevented this increase and larval survival doubled. Above-ground herbivory elevated root nitrogen, probably contributing to increased larval survival. However, plants increased foliar tannins with above-ground herbivory and below-ground herbivory amplified this increase, and adult survival decreased. As either foliar or root tannins increased, foliar flavonoids decreased, suggesting a trade-off between these chemicals. Together, these results show that plant chemicals mediate contrasting effects of conspecific larval and adult insects, whereas insects may take advantage of plant responses to facilitate their offspring performance, which may influence population dynamics. PMID:23902902

  12. Teaching Tips: Plant Tissue Testing.

    ERIC Educational Resources Information Center

    Osborne, Ed

    1991-01-01

    Plant tissue testing can be done to monitor plant nutrition levels during the growing season and diagnose nutrient deficiency problems. They can provide feedback on crop conditions and fertility needs. (Author)

  13. Effects of perchlorate on growth of four wetland plants and its accumulation in plant tissues.

    PubMed

    He, Hongzhi; Gao, Haishuo; Chen, Guikui; Li, Huashou; Lin, Hai; Shu, Zhenzhen

    2013-10-01

    Perchlorate contamination in water is of concern because of uncertainties about toxicity and health effects, impact on ecosystems, and possible indirect exposure pathways to humans. Therefore, it is very important to investigate the ecotoxicology of perchlorate and to screen plant species for phytoremediation. Effects of perchlorate (20, 200, and 500 mg/L) on the growth of four wetland plants (Eichhornia crassipes, Acorus calamus L., Thalia dealbata, and Canna indica) as well as its accumulation in different plant tissues were investigated through water culture experiments. Twenty milligrams per liter of perchlorate had no significant effects on height, root length, aboveground part weight, root weight, and oxidizing power of roots of four plants, except A. calamus, and increasing concentrations of perchlorate showed that out of the four wetland plants, only A. calamus had a significant (p<0.05) dose-dependent decrease in these parameters. When treated with 500 mg/L perchlorate, these parameters and chlorophyll content in the leaf of plants showed significant decline contrasted to control groups, except the root length of E. crassipes and C. indica. The order of inhibition rates of perchlorate on root length, aboveground part weight and root weight, and oxidizing power of roots was: A. calamus > C. indica > T. dealbata > E. crassipes and on chlorophyll content in the leaf it was: A. calamus > T. dealbata > C. indica > E. crassipes. The higher the concentration of perchlorate used, the higher the amount of perchlorate accumulation in plants. Perchlorate accumulation in aboveground tissues was much higher than that in underground tissues and leaf was the main tissue for perchlorate accumulation. The order of perchlorate accumulation content and the bioconcentration factor in leaf of four plants was: E. crassipes > C. indica > T. dealbata > A. calamus. Therefore, E. crassipes might be an ideal plant with high tolerance ability and accumulation ability for constructing

  14. The response of tundra plant biomass, above-ground production, nitrogen, and CO{sub 2} flux to experimental warming

    SciTech Connect

    Hobbie, S.E.; Chapin, F.S. III

    1998-07-01

    The authors manipulated air temperature in tussock tundra near Toolik Lake, Alaska, and determined the consequences for total plant biomass, aboveground net primary production (ANPP), ecosystem nitrogen (N) pools and N uptake, and ecosystem CO{sub 2} flux. After 3.5 growing seasons, in situ plastic greenhouses that raised air temperature during the growing season had little effect on total biomass, N content, or growing-season N uptake of the major plant and soil pools. Similarly, vascular ANPP and net ecosystem CO{sub 2} exchange did not change with warming, although net primary production of mosses decreased with warming. Such general lack of response supports the hypothesis that productivity in tundra is constrained by the indirect effects of cold temperatures rather than by cold growing-season temperatures per se. Despite no effect on net ecosystem CO{sub 2} flux, air warming stimulated early-season gross photosynthesis (GP) and ecosystem respiration (ER) throughout the growing season. This increased carbon turnover was probably associated with species-level responses to increased air temperature. Warming increased the aboveground biomass of the overstory shrub, dwarf birch (Betula nana), and caused a significant net redistribution of N from the understory evergreen shrub, Vaccinium vitis-idaea, to B. nana, despite no effects on soil temperature, total plant N, or N availability.

  15. Carbon dynamics in aboveground biomass of co-dominant plant species: related rather to leaf life span than to species

    NASA Astrophysics Data System (ADS)

    Ostler, Ulrike; Schleip, Inga; Lattanzi, Fernando A.; Schnyder, Hans

    2016-04-01

    This study investigates the role of individual organisms in whole ecosystem carbon (C) fluxes. It is currently unknown if different plant community members share the same or different kinetics of C pools in aboveground biomass, thereby adding (or not) variability to the first steps in ecosystem C cycling. We assessed the residence times in metabolic and non-metabolic (or structural) C pools and the allocation pattern of assimilated C in aboveground plant parts of four co-existing, co-dominant species from different functional groups in a temperate grassland community. For this purpose continuous, 14-16 day long 13CO2/12CO2-labeling experiments were performed in Sept. 2006, May 2007 and Sept. 2007, and the tracer kinetics were analysed with compartmental modeling. In all experimental periods, the species shared vastly similar residence times in metabolic C (5-8 d). In contrast, the residence times in non-metabolic C ranged from 20 to 58 d (except one outlier) and the fraction of fixed C allocated to the non-metabolic pool from 7 to 45%. These variations in non-metabolic C kinetics were not systematically associated with species or experimental periods, but exhibited close relationships with (independent estimates of) leaf life span, particularly in the grasses. This adds new meaning to leaf life span as a functional trait in the leaf and plant economics spectrum and its implication for C cycle studies in grassland and also forest systems. As the four co-dominant species accounted for ~80% of total community shoot biomass, we should also expect that the observed similarities in pool kinetics and allocation will scale up to similar relationships at the community level.

  16. A hyperspectral imaging system for an accurate prediction of the above-ground biomass of individual rice plants.

    PubMed

    Feng, Hui; Jiang, Ni; Huang, Chenglong; Fang, Wei; Yang, Wanneng; Chen, Guoxing; Xiong, Lizhong; Liu, Qian

    2013-09-01

    Biomass is an important component of the plant phenomics, and the existing methods for biomass estimation for individual plants are either destructive or lack accuracy. In this study, a hyperspectral imaging system was developed for the accurate prediction of the above-ground biomass of individual rice plants in the visible and near-infrared spectral region. First, the structure of the system and the influence of various parameters on the camera acquisition speed were established. Then the system was used to image 152 rice plants, which selected from the rice mini-core collection, in two stages, the tillering to elongation (T-E) stage and the booting to heading (B-H) stage. Several variables were extracted from the images. Following, linear stepwise regression analysis and 5-fold cross-validation were used to select effective variables for model construction and test the stability of the model, respectively. For the T-E stage, the R(2) value was 0.940 for the fresh weight (FW) and 0.935 for the dry weight (DW). For the B-H stage, the R(2) value was 0.891 for the FW and 0.783 for the DW. Moreover, estimations of the biomass using visible light images were also calculated. These comparisons showed that hyperspectral imaging performed better than the visible light imaging. Therefore, this study provides not only a stable hyperspectral imaging platform but also an accurate and nondestructive method for the prediction of biomass for individual rice plants. PMID:24089866

  17. Plant Host Species and Geographic Distance Affect the Structure of Aboveground Fungal Symbiont Communities, and Environmental Filtering Affects Belowground Communities in a Coastal Dune Ecosystem.

    PubMed

    David, Aaron S; Seabloom, Eric W; May, Georgiana

    2016-05-01

    Microbial symbionts inhabit tissues of all plants and animals. Their community composition depends largely on two ecological processes: (1) filtering by abiotic conditions and host species determining the environments that symbionts are able to colonize and (2) dispersal-limitation determining the pool of symbionts available to colonize a given host and community spatial structure. In plants, the above- and belowground tissues represent such distinct habitats for symbionts that we expect different effects of filtering and spatial structuring on their symbiont communities. In this study, we characterized above- and belowground communities of fungal endophytes--fungi living asymptomatically within plants--to understand the contributions of filtering and spatial structure to endophyte community composition. We used a culture-based approach to characterize endophytes growing in leaves and roots of three species of coastal beachgrasses in dunes of the USA Pacific Northwest. For leaves, endophyte isolation frequency and OTU richness depended primarily on plant host species. In comparison, for roots, both isolation frequency and OTU richness increased from the nutrient-poor front of the dune to the higher-nutrient backdune. Endophyte community composition in leaves exhibited a distance-decay relationship across the region. In a laboratory assay, faster growth rates and lower spore production were more often associated with leaf- than root-inhabiting endophytes. Overall, our results reveal a greater importance of biotic filtering by host species and dispersal-limitation over regional geographic distances for aboveground leaf endophyte communities and stronger effects of abiotic environmental filtering and locally patchy distributions for belowground root endophyte communities. PMID:26626912

  18. Plant-herbivore-carnivore interactions in cotton, Gossypium hirsutum: Linking belowground and aboveground

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Most studies on plant-herbivore interactions focus on either root or shoot herbivory in isolation, but above- and belowground herbivores may interact on a shared host plant. Cotton (Gossypium spp.) produces a variety of terpenoid aldehydes that exhibit toxicity to a wide range of herbivores and pat...

  19. Experimental Manipulation of Grassland Plant Diversity Induces Complex Shifts in Aboveground Arthropod Diversity

    PubMed Central

    Hertzog, Lionel R.; Meyer, Sebastian T.; Weisser, Wolfgang W.; Ebeling, Anne

    2016-01-01

    Changes in producer diversity cause multiple changes in consumer communities through various mechanisms. However, past analyses investigating the relationship between plant diversity and arthropod consumers focused only on few aspects of arthropod diversity, e.g. species richness and abundance. Yet, shifts in understudied facets of arthropod diversity like relative abundances or species dominance may have strong effects on arthropod-mediated ecosystem functions. Here we analyze the relationship between plant species richness and arthropod diversity using four complementary diversity indices, namely: abundance, species richness, evenness (equitability of the abundance distribution) and dominance (relative abundance of the dominant species). Along an experimental gradient of plant species richness (1, 2, 4, 8, 16 and 60 plant species), we sampled herbivorous and carnivorous arthropods using pitfall traps and suction sampling during a whole vegetation period. We tested whether plant species richness affects consumer diversity directly (i), or indirectly through increased productivity (ii). Further, we tested the impact of plant community composition on arthropod diversity by testing for the effects of plant functional groups (iii). Abundance and species richness of both herbivores and carnivores increased with increasing plant species richness, but the underlying mechanisms differed between the two trophic groups. While higher species richness in herbivores was caused by an increase in resource diversity, carnivore richness was driven by plant productivity. Evenness of herbivore communities did not change along the gradient in plant species richness, whereas evenness of carnivores declined. The abundance of dominant herbivore species showed no response to changes in plant species richness, but the dominant carnivores were more abundant in species-rich plant communities. The functional composition of plant communities had small impacts on herbivore communities, whereas

  20. Experimental Manipulation of Grassland Plant Diversity Induces Complex Shifts in Aboveground Arthropod Diversity.

    PubMed

    Hertzog, Lionel R; Meyer, Sebastian T; Weisser, Wolfgang W; Ebeling, Anne

    2016-01-01

    Changes in producer diversity cause multiple changes in consumer communities through various mechanisms. However, past analyses investigating the relationship between plant diversity and arthropod consumers focused only on few aspects of arthropod diversity, e.g. species richness and abundance. Yet, shifts in understudied facets of arthropod diversity like relative abundances or species dominance may have strong effects on arthropod-mediated ecosystem functions. Here we analyze the relationship between plant species richness and arthropod diversity using four complementary diversity indices, namely: abundance, species richness, evenness (equitability of the abundance distribution) and dominance (relative abundance of the dominant species). Along an experimental gradient of plant species richness (1, 2, 4, 8, 16 and 60 plant species), we sampled herbivorous and carnivorous arthropods using pitfall traps and suction sampling during a whole vegetation period. We tested whether plant species richness affects consumer diversity directly (i), or indirectly through increased productivity (ii). Further, we tested the impact of plant community composition on arthropod diversity by testing for the effects of plant functional groups (iii). Abundance and species richness of both herbivores and carnivores increased with increasing plant species richness, but the underlying mechanisms differed between the two trophic groups. While higher species richness in herbivores was caused by an increase in resource diversity, carnivore richness was driven by plant productivity. Evenness of herbivore communities did not change along the gradient in plant species richness, whereas evenness of carnivores declined. The abundance of dominant herbivore species showed no response to changes in plant species richness, but the dominant carnivores were more abundant in species-rich plant communities. The functional composition of plant communities had small impacts on herbivore communities, whereas

  1. Testing the generality of above-ground biomass allometry across plant functional types at the continent scale.

    PubMed

    Paul, Keryn I; Roxburgh, Stephen H; Chave, Jerome; England, Jacqueline R; Zerihun, Ayalsew; Specht, Alison; Lewis, Tom; Bennett, Lauren T; Baker, Thomas G; Adams, Mark A; Huxtable, Dan; Montagu, Kelvin D; Falster, Daniel S; Feller, Mike; Sochacki, Stan; Ritson, Peter; Bastin, Gary; Bartle, John; Wildy, Dan; Hobbs, Trevor; Larmour, John; Waterworth, Rob; Stewart, Hugh T L; Jonson, Justin; Forrester, David I; Applegate, Grahame; Mendham, Daniel; Bradford, Matt; O'Grady, Anthony; Green, Daryl; Sudmeyer, Rob; Rance, Stan J; Turner, John; Barton, Craig; Wenk, Elizabeth H; Grove, Tim; Attiwill, Peter M; Pinkard, Elizabeth; Butler, Don; Brooksbank, Kim; Spencer, Beren; Snowdon, Peter; O'Brien, Nick; Battaglia, Michael; Cameron, David M; Hamilton, Steve; McAuthur, Geoff; Sinclair, Jenny

    2016-06-01

    Accurate ground-based estimation of the carbon stored in terrestrial ecosystems is critical to quantifying the global carbon budget. Allometric models provide cost-effective methods for biomass prediction. But do such models vary with ecoregion or plant functional type? We compiled 15 054 measurements of individual tree or shrub biomass from across Australia to examine the generality of allometric models for above-ground biomass prediction. This provided a robust case study because Australia includes ecoregions ranging from arid shrublands to tropical rainforests, and has a rich history of biomass research, particularly in planted forests. Regardless of ecoregion, for five broad categories of plant functional type (shrubs; multistemmed trees; trees of the genus Eucalyptus and closely related genera; other trees of high wood density; and other trees of low wood density), relationships between biomass and stem diameter were generic. Simple power-law models explained 84-95% of the variation in biomass, with little improvement in model performance when other plant variables (height, bole wood density), or site characteristics (climate, age, management) were included. Predictions of stand-based biomass from allometric models of varying levels of generalization (species-specific, plant functional type) were validated using whole-plot harvest data from 17 contrasting stands (range: 9-356 Mg ha(-1) ). Losses in efficiency of prediction were <1% if generalized models were used in place of species-specific models. Furthermore, application of generalized multispecies models did not introduce significant bias in biomass prediction in 92% of the 53 species tested. Further, overall efficiency of stand-level biomass prediction was 99%, with a mean absolute prediction error of only 13%. Hence, for cost-effective prediction of biomass across a wide range of stands, we recommend use of generic allometric models based on plant functional types. Development of new species

  2. Longevity of contributions to SOC stocks from roots and aboveground plant litter below a Miscanthus plantation

    NASA Astrophysics Data System (ADS)

    Robertson, Andrew; Smith, Pete; Davies, Christian; Bottoms, Emily; McNamara, Niall

    2013-04-01

    Miscanthus is a lignocellulosic crop that uses the Hatch-Slack (C4) photosynthetic pathway as opposed to most C3 vegetation native to the UK. Miscanthus can be grown for a number of practical end-uses but recently interest has increased in its viability as a bioenergy crop; both providing a renewable source of energy and helping to limit climate change by improving the carbon (C) budgets associated with energy generation. Recent studies have shown that Miscanthus plantations may increase stocks of soil organic carbon (SOC), however the longevity and origin of this 'new' SOC must be assessed. Consequently, we combined an input manipulation experiment with physio-chemical soil fractionation to quantify new SOC and CO2 emissions from Miscanthus roots, decomposing plant litter and soil individually. Further, fractionation of SOC from the top 30 cm gave insight into the longevity of that SOC. In January 2009 twenty-five 2 m2 plots were set up in a three-year old 11 hectare Miscanthus plantation in Lincolnshire, UK; with five replicates of five treatments. These treatments varied plant input to the soil by way of controlled exclusion techniques. Treatments excluded roots only ("No Roots"), surface litter only ("No Litter"), both roots and surface litter ("No Roots or Litter") or had double the litter amount added to the soil surface ("Double Litter"). A fifth treatment was a control with undisturbed roots and an average amount of litter added. Monthly measurements of CO2 emissions were taken at the soil surface from each treatment between March 2009 and March 2013, and soil C from the top 30 cm was monitored in all plots over the same period. Miscanthus-derived SOC was determined using the isotopic discrimination between C4 plant matter and C3 soil, and soil fractionation was then used to establish the longevity of that Miscanthus-derived SOC. Ongoing results for CO2 emissions indicate a strong seasonal variation; litter decomposition forms a large portion of the CO2

  3. Recovery of aboveground plant biomass and productivity after fire in mesic and dry black spruce forests of interior Alaska

    USGS Publications Warehouse

    Mack, M.C.; Treseder, K.K.; Manies, K.L.; Harden, J.W.; Schuur, E.A.G.; Vogel, J.G.; Randerson, J.T.; Chapin, F. S., III

    2008-01-01

    Plant biomass accumulation and productivity are important determinants of ecosystem carbon (C) balance during post-fire succession. In boreal black spruce (Picea mariana) forests near Delta Junction, Alaska, we quantified aboveground plant biomass and net primary productivity (ANPP) for 4 years after a 1999 wildfire in a well-drained (dry) site, and also across a dry and a moderately well-drained (mesic) chronosequence of sites that varied in time since fire (2 to ???116 years). Four years after fire, total biomass at the 1999 burn site had increased exponentially to 160 ?? 21 g m-2 (mean ?? 1SE) and vascular ANPP had recovered to 138 ?? 32 g m-2 y -1, which was not different than that of a nearby unburned stand (160 ?? 48 g m-2 y-1) that had similar pre-fire stand structure and understory composition. Production in the young site was dominated by re-sprouting graminoids, whereas production in the unburned site was dominated by black spruce. On the dry and mesic chronosequences, total biomass pools, including overstory and understory vascular and non-vascular plants, and lichens, increased logarithmically (dry) or linearly (mesic) with increasing site age, reaching a maximum of 2469 ?? 180 (dry) and 4008 ?? 233 g m-2 (mesic) in mature stands. Biomass differences were primarily due to higher tree density in the mesic sites because mass per tree was similar between sites. ANPP of vascular and non-vascular plants increased linearly over time in the mesic chronosequence to 335 ?? 68 g m-2 y -1 in the mature site, but in the dry chronosequence it peaked at 410 ?? 43 g m-2 y-1 in a 15-year-old stand dominated by deciduous trees and shrubs. Key factors regulating biomass accumulation and production in these ecosystems appear to be the abundance and composition of re-sprouting species early in succession, the abundance of deciduous trees and shrubs in intermediate aged stands, and the density of black spruce across all stand ages. A better understanding of the controls

  4. Interrelated effects of mycorrhiza and free-living nitrogen fixers cascade up to aboveground herbivores

    PubMed Central

    Khaitov, Botir; Patiño-Ruiz, José David; Pina, Tatiana; Schausberger, Peter

    2015-01-01

    Aboveground plant performance is strongly influenced by belowground microorganisms, some of which are pathogenic and have negative effects, while others, such as nitrogen-fixing bacteria and arbuscular mycorrhizal fungi, usually have positive effects. Recent research revealed that belowground interactions between plants and functionally distinct groups of microorganisms cascade up to aboveground plant associates such as herbivores and their natural enemies. However, while functionally distinct belowground microorganisms commonly co-occur in the rhizosphere, their combined effects, and relative contributions, respectively, on performance of aboveground plant-associated organisms are virtually unexplored. Here, we scrutinized and disentangled the effects of free-living nitrogen-fixing (diazotrophic) bacteria Azotobacter chroococcum (DB) and arbuscular mycorrhizal fungi Glomus mosseae (AMF) on host plant choice and reproduction of the herbivorous two-spotted spider mite Tetranychus urticae on common bean plants Phaseolus vulgaris. Additionally, we assessed plant growth, and AMF and DB occurrence and density as affected by each other. Both AMF alone and DB alone increased spider mite reproduction to similar levels, as compared to the control, and exerted additive effects under co-occurrence. These effects were similarly apparent in host plant choice, that is, the mites preferred leaves from plants with both AMF and DB to plants with AMF or DB to plants grown without AMF and DB. DB, which also act as AMF helper bacteria, enhanced root colonization by AMF, whereas AMF did not affect DB abundance. AMF but not DB increased growth of reproductive plant tissue and seed production, respectively. Both AMF and DB increased the biomass of vegetative aboveground plant tissue. Our study breaks new ground in multitrophic belowground–aboveground research by providing first insights into the fitness implications of plant-mediated interactions between interrelated belowground fungi

  5. Drivers of variation in aboveground net primary productivity and plant community composition differe across a broad precipitation gradient

    Technology Transfer Automated Retrieval System (TEKTRAN)

    It has long been a goal of ecology to determine what factors drive variation in aboveground net primary production (ANPP). Total annual precipitation has been shown to be a strong predictor of ANPP across broad spatial scales, but a poor predictor at local scales. Here we aim to determine the amount...

  6. Plant Tissue Culture in a Bag.

    ERIC Educational Resources Information Center

    Beck, Mike

    2000-01-01

    Describes the use of an oven bag as a sterile chamber for culture initiation and tissue transfer. Plant tissue culture is an ideal tool for introducing students to plants, cloning, and experimental design. Includes materials, methods, discussion, and conclusion sections. (SAH)

  7. Plant tissue extraction for metabolomics.

    PubMed

    Roessner, Ute; Dias, Daniel Anthony

    2013-01-01

    Plants are not only important producers of foods and energy storages (e.g., sugars, carbohydrates, proteins, and fats) in the form of grains, fruits, and vegetables, they also provide many valuable products to human existence including wood, fibers, oils, resins, pigments, antioxidants, and sources of medicine. Most importantly in light of this book, plants have been a source of therapeutic and health promoting compounds throughout history. This chapter describes several essential considerations for the extraction process when aiming to study plant metabolism or to characterize the chemical composition of plant originated samples using metabolomics technologies. PMID:23963900

  8. Soil water content and patterns of allocation to below- and above-ground biomass in the sexes of the subdioecious plant Honckenya peploides

    PubMed Central

    Sánchez-Vilas, Julia; Bermúdez, Raimundo; Retuerto, Rubén

    2012-01-01

    Background and aims Dioecious plants often show sex-specific differences in growth and biomass allocation. These differences have been explained as a consequence of the different reproductive functions performed by the sexes. Empirical evidence strongly supports a greater reproductive investment in females. Sex differences in allocation may determine the performance of each sex in different habitats and therefore might explain the spatial segregation of the sexes described in many dimorphic plants. Here, an investigation was made of the sexual dimorphism in seasonal patterns of biomass allocation in the subdioecious perennial herb Honckenya peploides, a species that grows in embryo dunes (i.e. the youngest coastal dune formation) and displays spatial segregation of the sexes at the studied site. The water content in the soil of the male- and female-plant habitats at different times throughout the season was also examined. Methods The seasonal patterns of soil-water availability and biomass allocation were compared in two consecutive years in male and female H. peploides plants by collecting soil and plant samples in natural populations. Vertical profiles of below-ground biomass and water content were studied by sampling soil in male- and female-plant habitats at different soil depths. Key Results The sexes of H. peploides differed in their seasonal patterns of biomass allocation to reproduction. Males invested twice as much in reproduction than females early in the season, but sexual differences became reversed as the season progressed. No differences were found in above-ground biomass between the sexes, but the allocation of biomass to below-ground structures varied differently in depth for males and females, with females usually having greater below-ground biomass than males. In addition, male and female plants of H. peploides had different water-content profiles in the soil where they were growing and, when differences existed (usually in the upper layers of the

  9. Biotransformations with plant tissue cultures.

    PubMed

    Carew, D P; Bainbridge, T

    1976-01-01

    Suspension cultures of Catharanthus roseus, Apocynum cannabinum and Conium maculatum were examined for their capacity to transform aniline, anisole, acetanilide, benzoic acid and coumarin. None of the cultures transformed acetanilide but each produced acetanilide when fed aniline. All three cultures converted benzoic acid to its para-hydroxy derivative. Coumarin was selectively hydroxylated at the 7-position by Catharanthus and Conium and anisole was O-demethylated only by older Catharanthus tissue. PMID:1084950

  10. Potato tuber herbivory increases resistance to aboveground lepidopteran herbivores.

    PubMed

    Kumar, Pavan; Ortiz, Erandi Vargas; Garrido, Etzel; Poveda, Katja; Jander, Georg

    2016-09-01

    Plants mediate interactions between aboveground and belowground herbivores. Although effects of root herbivory on foliar herbivores have been documented in several plant species, interactions between tuber-feeding herbivores and foliar herbivores are rarely investigated. We report that localized tuber damage by Tecia solanivora (Guatemalan tuber moth) larvae reduced aboveground Spodoptera exigua (beet armyworm) and Spodoptera frugiperda (fall armyworm) performance on Solanum tuberosum (potato). Conversely, S. exigua leaf damage had no noticeable effect on belowground T. solanivora performance. Tuber infestation by T. solanivora induced systemic plant defenses and elevated resistance to aboveground herbivores. Lipoxygenase 3 (Lox3), which contributes to the synthesis of plant defense signaling molecules, had higher transcript abundance in T. solanivora-infested leaves and tubers than in equivalent control samples. Foliar expression of the hydroxycinnamoyl-CoA quinate hydroxycinnamoyl transferase (HQT) and 3-hydroxy-3-methylglutaryl CoA reductase I (HMGR1) genes, which are involved in chlorogenic acid and steroidal glycoalkaloid biosynthesis, respectively, also increased in response to tuber herbivory. Leaf metabolite profiling demonstrated the accumulation of unknown metabolites as well as the known potato defense compounds chlorogenic acid, α-solanine, and α-chaconine. When added to insect diet at concentrations similar to those found in potato leaves, chlorogenic acid, α-solanine, and α-chaconine all reduced S. exigua larval growth. Thus, despite the fact that tubers are a metabolic sink tissue, T. solanivora feeding elicits a systemic signal that induces aboveground resistance against S. exigua and S. frugiperda by increasing foliar abundance of defensive metabolites. PMID:27147449

  11. Content of lead and cadmium in aboveground plant organs of grasses growing on the areas adjacent to a route of big traffic.

    PubMed

    Jankowski, K; Ciepiela, A G; Jankowska, J; Szulc, W; Kolczarek, R; Sosnowski, J; Wiśniewska-Kadżajan, B; Malinowska, E; Radzka, E; Czeluściński, W; Deska, J

    2015-01-01

    The effect of traffic on the content of lead and cadmium in grass morphological parts-leaves, shoots, and inflorescences-was studied. The samples were taken on a part of the European route E30 (Siedlce by road). The following plants were tested: Dactylis glomerata, Arrhenatherum elatius, and Alopecurus pratensis. During the flowering of grasses, the plant material was collected at distances of 1, 5, 10, and 15 m from the edge of the road, on the strip of road with a length of 9 km. In the collected plant parts, the content of lead and cadmium using the atomic absorption spectroscopy (AAS) method was determined. The effect of distance from the road on the content of lead and cadmium was evaluated using regression equations. Average lead content in the above parts of tested grass species was 3.56, while cadmium 0.307 mg kg(-1) dry matter (DM). Lead content in plants of Alopecurus pratensis (average 4.11 mg kg(-1) DM) was significantly higher than in other grasses. The lowest cadmium content, significantly different from the other species, was found in plants of Arrhenatherum elatius (0.251 mg kg(-1) DM). Distance of sampling sites from the roadway significantly affects the differences in the content of cadmium and lead in plants. Analyzed aboveground plant organs of studied grasses were significantly different in contents of lead and cadmium. There were species differences in the proportions of cadmium concentration in various organs of plants. The obtained results indicate the possibility of species composition selection of grassland sward in areas with a higher risk of heavy metals associated with dust sedimentation. PMID:25292297

  12. Different bacterial communities in heat and gamma irradiation treated replant disease soils revealed by 16S rRNA gene analysis - contribution to improved aboveground apple plant growth?

    PubMed

    Yim, Bunlong; Winkelmann, Traud; Ding, Guo-Chun; Smalla, Kornelia

    2015-01-01

    Replant disease (RD) severely affects apple production in propagation tree nurseries and in fruit orchards worldwide. This study aimed to investigate the effects of soil disinfection treatments on plant growth and health in a biotest in two different RD soil types under greenhouse conditions and to link the plant growth status with the bacterial community composition at the time of plant sampling. In the biotest performed we observed that the aboveground growth of apple rootstock M26 plants after 8 weeks was improved in the two RD soils either treated at 50°C or with gamma irradiation compared to the untreated RD soils. Total community DNA was extracted from soil loosely adhering to the roots and quantitative real-time PCR revealed no pronounced differences in 16S rRNA gene copy numbers. 16S rRNA gene-based bacterial community analysis by denaturing gradient gel electrophoresis (DGGE) and 454-pyrosequencing revealed significant differences in the bacterial community composition even after 8 weeks of plant growth. In both soils, the treatments affected different phyla but only the relative abundance of Acidobacteria was reduced by both treatments. The genera Streptomyces, Bacillus, Paenibacillus, and Sphingomonas had a higher relative abundance in both heat treated soils, whereas the relative abundance of Mucilaginibacter, Devosia, and Rhodanobacter was increased in the gamma-irradiated soils and only the genus Phenylobacterium was increased in both treatments. The increased abundance of genera with potentially beneficial bacteria, i.e., potential degraders of phenolic compounds might have contributed to the improved plant growth in both treatments. PMID:26635733

  13. Pathways of Leymus chinensis Individual Aboveground Biomass Decline in Natural Semiarid Grassland Induced by Overgrazing: A Study at the Plant Functional Trait Scale.

    PubMed

    Li, Xiliang; Liu, Zhiying; Wang, Zhen; Wu, Xinhong; Li, Xinle; Hu, Jing; Shi, Hongxiao; Guo, Fenghui; Zhang, Yong; Hou, Xiangyang

    2015-01-01

    Natural grassland productivity, which is based on an individual plant's aboveground biomass (AB) and its interaction with herbivores, can obviously affect terrestrial ecosystem services and the grassland's agricultural production. As plant traits have been linked to both AB and ecosystem success, they may provide a useful approach to understand the changes in individual plants and grassland productivity in response to grazing on a generic level. Unfortunately, the current lack of studies on how plant traits affect AB affected by herbivores leaves a major gap in our understanding of the mechanism of grassland productivity decline. This study, therefore, aims to analyze the paths of overgrazing-induced decline in the individual AB of Leymus chinensis (the dominant species of meadow-steppe grassland in northern China) on a plant functional trait scale. Using a paired-sampling approach, we compared the differences in the functional traits of L. chinensis in long-term grazing-excluded and experimental grazing grassland plots over a continuous period of approximately 20 years (located in meadow steppe lands in Hailar, Inner Mongolia, China). We found a highly significant decline in the individual height and biomass (leaf, stem, and the whole plant) of L. chinensis as a result of overgrazing. Biomass allocation and leaf mass per unit area were significantly affected by the variation in individual size. Grazing clearly enhanced the sensitivity of the leaf-to-stem biomass ratio in response to variation in individual size. Moreover, using a method of standardized major axis estimation, we found that the biomass in the leaves, stems, and the plant as a whole had highly significant allometric scaling with various functional traits. Also, the slopes of the allometric equations of these relationships were significantly altered by grazing. Therefore, a clear implication of this is that grazing promotes an asymmetrical response of different plant functional traits to variation in

  14. Pathways of Leymus chinensis Individual Aboveground Biomass Decline in Natural Semiarid Grassland Induced by Overgrazing: A Study at the Plant Functional Trait Scale

    PubMed Central

    Wang, Zhen; Wu, Xinhong; Li, Xinle; Hu, Jing; Shi, Hongxiao; Guo, Fenghui; Zhang, Yong; Hou, Xiangyang

    2015-01-01

    Natural grassland productivity, which is based on an individual plant’s aboveground biomass (AB) and its interaction with herbivores, can obviously affect terrestrial ecosystem services and the grassland’s agricultural production. As plant traits have been linked to both AB and ecosystem success, they may provide a useful approach to understand the changes in individual plants and grassland productivity in response to grazing on a generic level. Unfortunately, the current lack of studies on how plant traits affect AB affected by herbivores leaves a major gap in our understanding of the mechanism of grassland productivity decline. This study, therefore, aims to analyze the paths of overgrazing-induced decline in the individual AB of Leymus chinensis (the dominant species of meadow-steppe grassland in northern China) on a plant functional trait scale. Using a paired-sampling approach, we compared the differences in the functional traits of L. chinensis in long-term grazing-excluded and experimental grazing grassland plots over a continuous period of approximately 20 years (located in meadow steppe lands in Hailar, Inner Mongolia, China). We found a highly significant decline in the individual height and biomass (leaf, stem, and the whole plant) of L. chinensis as a result of overgrazing. Biomass allocation and leaf mass per unit area were significantly affected by the variation in individual size. Grazing clearly enhanced the sensitivity of the leaf-to-stem biomass ratio in response to variation in individual size. Moreover, using a method of standardized major axis estimation, we found that the biomass in the leaves, stems, and the plant as a whole had highly significant allometric scaling with various functional traits. Also, the slopes of the allometric equations of these relationships were significantly altered by grazing. Therefore, a clear implication of this is that grazing promotes an asymmetrical response of different plant functional traits to variation

  15. Plant tissue optics: micro- and nanostructures

    NASA Astrophysics Data System (ADS)

    Lee, David W.

    2009-08-01

    Plants have evolved unusual tissue optical properties, not surprising as creatures of light. These are astonishingly sophisticated, involving both micro- and nanostructures. Microstructures refract, scatter, and channel light in plant tissues, to produce concentrations and gradients of light within, and to remove undesired portions of the electromagnetic spectrum. Nanostructures use the different refractive indices of both cellulosic walls and bi-lipid membranes to interfere with light, multiple layers producing intense constructive coloration and reduced fluxes within tissues. In a tropical sedge now under analysis, structures may include silica. Recently discovered surface diffraction gratings produce strong directionally sensitive coloration that assist in pollinator visitation. Although some of these properties have obvious applications, most await appreciation by creative scientists to produce new useful devices.

  16. Influence of the Wax Lake Delta sediment diversion on aboveground plant productivity and carbon storage in deltaic island and mainland coastal marshes

    NASA Astrophysics Data System (ADS)

    DeLaune, R. D.; Sasser, C. E.; Evers-Hebert, E.; White, J. R.; Roberts, H. H.

    2016-08-01

    Coastal Louisiana is experiencing a significant loss of coastal wetland area due to increasing sea level rise, subsidence, sediment starvation and marsh collapse. The construction of large scale Mississippi River sediment diversions is currently being planned in an effort to help combat coastal wetlands losses at a rate of >50 km-2 y-1. The Wax Lake Delta (WLD) is currently being used as a model for evaluating potential land gain from large scale diversions of Mississippi River water and sediment. In this study, we determine the impact of the WLD diversion on plant production at newly formed islands within the delta and adjacent, mainland freshwater marshes. Plant aboveground productivity, sediment nutrient status and short term accretion were measured at three locations on a transect at each of three fresh water marsh sites along Hog Bayou and at six newly formed emerging island sites in the delta. Spring flooding has resulted in a greater increase in plant production and consequently, greater carbon sequestration potential in adjacent mainland marshes compared to the newly formed island sites, which contain less total carbon (C), nitrogen (N), and phosphorus (P) in the sediment. While sediment diversions are predicted to create land, as seen in island formation in the WLD, the greatest benefit of river sediment diversions from a carbon credit perspective might be to the adjacent freshwater mainland marshes for several reasons. Both greater plant production and sediment C accumulation are two important factors for marsh stability, while perhaps even more critical, is the prevention of the loss of stored sediment C in the marsh profile. This stored C would be lost without the introduction of freshwater, nutrients and sediment through river sediment diversion efforts.

  17. Plant composition and the effects of temperature, soil moisture, and aboveground biomass on soil respiration in grassland

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Future changes in climate are likely to cause shifts in plant species composition. In grasslands, the growth form composition (i.e., grass/forb) and species diversity of vegetation are important controls on ecosystem carbon cycling because species and growth forms vary in their capacities for carbon...

  18. Lipid hydroperoxide levels in plant tissues.

    PubMed

    Griffiths, G; Leverentz, M; Silkowski, H; Gill, N; Sánchez-Serrano, J J

    2000-08-01

    Hydroperoxides are the primary oxygenated products of polyunsaturated fatty acids and are key intermediates in the octadecanoid signalling pathway in plants. Lipid hydroperoxides (LHPO) were determined spectrophotometrically based on their reaction with an excess of Fe(2+)at low pH in the presence of the dye xylenol orange. Triphenylphosphine-mediated hydroxide formation was used to authenticate the signal generated by the hydroperoxides. The method readily detected lipid peroxidation in Phaseolus: microsomes, senescing potato leaves and in a range of other plant tissues including Phaseolus hypocotyls (26+/-5 nmol g(-1) FW), Alstroemeria floral tissues (sepals 66+/-13 nmol g(-1) FW petals 49+/-6 nmol g(-1) FW), potato leaves (334+/-75 nmol g(-1) FW), broccoli florets (568+/-68 nmol g(-1) FW) and Chlamydomonas cells (602+/-40 nmol g(-1) FW). Relative to the total fatty acid content of the tissues, the % LHPO was within the range of 0.6-1.7% for all tissue types (photosynthetic and non-photosynthetic) and represents the basal oxidation level of membrane fatty acids in plant cells. In order to relate the levels of LHPO to specific signalling pathways, transgenic potato plant lines were used in which lipoxygenase (LOX) (responsible for hydroperoxide biosynthesis) and hydroperoxide lyase (a route of hydroperoxide degradation) activities were largely reduced by an antisense-mediated approach. While the LHPO levels were similar to wild type in the individual LOX antisensed plants, basal LHPO levels, by contrast, were elevated by 38% in transgenic potato leaves antisensed in hydroperoxide lyase, indicating a role for this enzyme in the maintenance of cellular levels of LHPOs. PMID:10944149

  19. Plant tissue and the color infrared record

    NASA Technical Reports Server (NTRS)

    Pease, R. W.

    1969-01-01

    Green plant tissue should not be considered as having a uniguely high near-infrared reflectance but rather a low visual reflectance. Leaf tissue without chloroplasts appears to reflect well both visual and near infrared wavelengths. The sensitometry of color infrared film is such that a spectral imbalance strongly favoring infrared reflection is necessary to yield a red record. It is the absorption of visual light by chlorophyll that creates the imbalance that makes the typical red record for plants possible. Reflectance measurements of leaves that have been chemically blanched or which have gone into natural chloride decline strongly suggests that it is the rise in the visual reflectance that is most important in removing the imbalance and degrading the red CIR record. The role of water in leaves appears to be that of rendering epidermal membranes translucent so that the underlying chlorophyll controls the reflection rather than the leaf surface.

  20. Preparation of genomic DNA from plant tissue.

    PubMed

    Richards, E; Reichardt, M; Rogers, S

    2001-05-01

    This unit describes two methods for preparing genomic DNA from plant tissue. In the first method, plant cells are lysed with ionic detergent, treated with protease, and subsequently purified by cesium chloride (CsCl) density gradient centrifugation. The second method is based upon a series of treatments with the nonionic detergent cetyltrimethylammonium bromide (CTAB) to lyse cells and purify nucleic acid. Nucleic acid is recovered from the final CTAB solution by isopropanol or ethanol precipitation. The first method, although somewhat more lengthy, results in highly purified nucleic acid. The second method requires fewer manipulations, results in very high yields (approximately 10-fold higher per gram fresh tissue depending on species and condition of starting material), and produces DNA that is less pure but nonetheless suitable in quality for use in many molecular biology manipulations. PMID:18265183

  1. Aboveground storage tank regulations

    SciTech Connect

    Geyer, W. )

    1993-01-01

    There are critical differences between the potential for environmental impact of aboveground and underground oil storage. For example, while leaks from underground storage tanks (USTs) seep into soil or aquifers, the concern with aboveground storage tanks (ASTs) is that an overfill or tank rupture can cause product to escape into a navigable stream and immediately create an oil spill pollution incident. The US Environmental Protection Agency (EPA) has very distinct programs outlining regulation parameters for each type of storage, including source of authority, regulatory cutoffs and exclusions, definitions, prevention and response requirements, and penalties, etc. Engineers considering changes or recommending a change in type of storage, particularly from a UST to an AST, need to be aware of existing federal regulations. Since the federal UST program began, remediation costs have skyrocketed as a result of the need to clean up leaking tank and piping sites, backfill and surrounding soil or groundwater. Compliance with federal and state UST regulations has not been cheap, and is expected to top $23 billion, according to some estimates. Partly as a result, market demand has shifted toward use of aboveground storage tanks, a trend that is expected to continue. Industry figures show a 100% increase in factory fabricated aboveground tank activity during the last four years.

  2. Histochemical detection of lead in plant tissues

    SciTech Connect

    Tung, G.; Temple, P.J.

    1996-06-01

    A histochemical staining technique using sodium rhodizonate was developed for detecting lead in living or preserved plant tissues. Sodium rhodizonate formed a bright scarlet-red precipitate with lead at pH 3.0, but showed no significant color responses with other metals. The precipitation of lead by this staining technique was confirmed by detection of lead in the red-stained precipitate with electron microscopy X-ray analysis. This histochemical technique for lead provided rapid, quantifiable, and unambiguous evidence for the accumulation and localization of lead in plant tissues. Soil-borne lead accumulated primarily in the roots, although at high concentrations, lead also accumulated at the ends of transpirational streams, particularly at hydathodes, trichomes, and the termini of xylem streams. Lead deposited from the atmosphere accumulated on the surface of conifer foliage and also appeared in or on cell walls of various internal cells and tissues. Lead concentrations in foliage and the color intensity of the stained deposits in spruce foliage decreased with distance from the lead source and increased with age of needles. No evidence of lead deposition inside cell contents was observed by this stain.

  3. Removal of dissolved metals by plant tissue

    SciTech Connect

    Scott, C.D. )

    1992-04-25

    Various types of microbial biomass have been shown to adsorb metals dissolved in aqueous media. It has now been demonstrated that certain plant tissues are also effective for this type of adsorption process. In particular, tomato and tobacco roots harvested from field-grown plants were shown to adsorb Sr from an aqueous solution of SrCl[sub 2]. Distribution coefficients in excess of 550 were measured and the adsorption isotherms at 25 C could be fitted to Langmuir-type expressions. The bioadsorbent could be regenerated and metals recovered by either a reduction in the pH to less than 2.0 or by use of a concentrated chloride salt solution.

  4. Impacts of cattle grazing on spatio-temporal variability of soil moisture and above-ground live plant biomass in mixed grasslands

    NASA Astrophysics Data System (ADS)

    Virk, Ravinder

    Areas with relatively high spatial heterogeneity generally have more biodiversity than spatially homogeneous areas due to increased potential habitat. Management practices such as controlled grazing also affect the biodiversity in grasslands, but the nature of this impact is not well understood. Therefore this thesis studies the impacts of variation in grazing on soil moisture and biomass heterogeneity. These are not only important in terms of management of protected grasslands, but also for designing an effective grazing system from a livestock management point of view. This research is a part of the cattle grazing experiment underway in Grasslands National Park (GNP) of Canada since 2006, as part of the adaptive management process for restoring ecological integrity of the northern mixed-grass prairie region. An experimental approach using field measurements and remote sensing (Landsat) was combined with modelling (CENTURY) to examine and predict the impacts of grazing intensity on the spatial heterogeneity and patterns of above-ground live plant biomass (ALB) in experimental pastures in a mixed grassland ecosystem. The field-based research quantified the temporal patterns and spatial variability in both soil moisture (SM) and ALB, and the influence of local intra-seasonal weather variability and slope location on the spatio-temporal variability of SM and ALB at field plot scales. Significant impacts of intra-seasonal weather variability, slope position and grazing pressure on SM and ALB across a range of scales (plot and local (within pasture)) were found. Grazing intensity significantly affected the ALB even after controlling for the effect of slope position. Satellite-based analysis extended the scale of interest to full pastures and the surrounding region to assess the effects of grazing intensity on the spatio-temporal pattern of ALB in mixed grasslands. Overall, low to moderate grazing intensity showed increase in ALB heterogeneity whereas no change in ALB

  5. Tissue-Culture Method of Cloning Rubber Plants

    NASA Technical Reports Server (NTRS)

    Ball, E. A.

    1983-01-01

    Guayule plant, a high-yield rubber plant cloned by tissue-culture method to produce multiple new plants that mature quickly. By adjusting culture medium, excised shoot tip produces up to 50 identical guayule plants. Varying concentration of cytokinin, single excised tip produces either 1 or several (up to 50) new plants.

  6. Drought and root herbivory interact to alter the response of above-ground parasitoids to aphid infested plants and associated plant volatile signals.

    PubMed

    Tariq, Muhammad; Wright, Denis J; Bruce, Toby J A; Staley, Joanna T

    2013-01-01

    Multitrophic interactions are likely to be altered by climate change but there is little empirical evidence relating the responses of herbivores and parasitoids to abiotic factors. Here we investigated the effects of drought on an above/below-ground system comprising a generalist and a specialist aphid species (foliar herbivores), their parasitoids, and a dipteran species (root herbivore).We tested the hypotheses that: (1) high levels of drought stress and below-ground herbivory interact to reduce the performance of parasitoids developing in aphids; (2) drought stress and root herbivory change the profile of volatile organic chemicals (VOCs) emitted by the host plant; (3) parasitoids avoid ovipositing in aphids feeding on plants under drought stress and root herbivory. We examined the effect of drought, with and without root herbivory, on the olfactory response of parasitoids (preference), plant volatile emissions, parasitism success (performance), and the effect of drought on root herbivory. Under drought, percentage parasitism of aphids was reduced by about 40-55% compared with well watered plants. There was a significant interaction between drought and root herbivory on the efficacy of the two parasitoid species, drought stress partially reversing the negative effect of root herbivory on percent parasitism. In the absence of drought, root herbivory significantly reduced the performance (e.g. fecundity) of both parasitoid species developing in foliar herbivores. Plant emissions of VOCs were reduced by drought and root herbivores, and in olfactometer experiments parasitoids preferred the odour from well-watered plants compared with other treatments. The present work demonstrates that drought stress can change the outcome of interactions between herbivores feeding above- and below-ground and their parasitoids, mediated by changes in the chemical signals from plants to parasitoids. This provides a new insight into how the structure of terrestrial communities may be

  7. Drought and Root Herbivory Interact to Alter the Response of Above-Ground Parasitoids to Aphid Infested Plants and Associated Plant Volatile Signals

    PubMed Central

    Tariq, Muhammad; Wright, Denis J.; Bruce, Toby J. A.; Staley, Joanna T.

    2013-01-01

    Multitrophic interactions are likely to be altered by climate change but there is little empirical evidence relating the responses of herbivores and parasitoids to abiotic factors. Here we investigated the effects of drought on an above/below-ground system comprising a generalist and a specialist aphid species (foliar herbivores), their parasitoids, and a dipteran species (root herbivore).We tested the hypotheses that: (1) high levels of drought stress and below-ground herbivory interact to reduce the performance of parasitoids developing in aphids; (2) drought stress and root herbivory change the profile of volatile organic chemicals (VOCs) emitted by the host plant; (3) parasitoids avoid ovipositing in aphids feeding on plants under drought stress and root herbivory. We examined the effect of drought, with and without root herbivory, on the olfactory response of parasitoids (preference), plant volatile emissions, parasitism success (performance), and the effect of drought on root herbivory. Under drought, percentage parasitism of aphids was reduced by about 40–55% compared with well watered plants. There was a significant interaction between drought and root herbivory on the efficacy of the two parasitoid species, drought stress partially reversing the negative effect of root herbivory on percent parasitism. In the absence of drought, root herbivory significantly reduced the performance (e.g. fecundity) of both parasitoid species developing in foliar herbivores. Plant emissions of VOCs were reduced by drought and root herbivores, and in olfactometer experiments parasitoids preferred the odour from well-watered plants compared with other treatments. The present work demonstrates that drought stress can change the outcome of interactions between herbivores feeding above- and below-ground and their parasitoids, mediated by changes in the chemical signals from plants to parasitoids. This provides a new insight into how the structure of terrestrial communities may

  8. Aboveground and belowground competition between willow Salix caprea its understory

    NASA Astrophysics Data System (ADS)

    Mudrák, Ondřej; Hermová, Markéta; Frouz, Jan

    2016-04-01

    The effects of aboveground and belowground competition with the willow S. caprea on its understory plant community were studied in unreclaimed post-mining sites. Belowground competition was evaluated by comparing (i) frames inserted into the soil that excluded woody roots (frame treatment), (ii) frames that initially excluded woody root growth but then allowed regrowth of the roots (open-frame treatment), and (iii) undisturbed soil (no-frame treatment). These treatments were combined with S. caprea thinning to assess the effect of aboveground competition. Three years after the start of the experiment, aboveground competition from S. caprea (as modified by thinning of the S. caprea canopy) had not affected understory biomass or species number but had affected species composition. In contrast, belowground competition significantly affected both the aboveground and belowground biomass of the understory. The aboveground biomass of the understory was greater in the frame treatment (which excluded woody roots) than in the other two treatments. The belowground biomass of the understory was greater in the frame than in the open-frame treatment. Unlike aboveground competition (light availability), belowground competition did not affect understory species composition. Our results suggest that S. caprea is an important component during plant succession on post-mining sites because it considerably modifies its understory plant community. Belowground competition is a major reason for the low cover and biomass of the herbaceous understory in S. caprea stands on post-mining sites.

  9. Biogenesis of Oxalate in Plant Tissues

    PubMed Central

    Chang, Chi-Cheng; Beevers, Harry

    1968-01-01

    Red beet root discs aerated in potassium phosphate for 2 to 3 days and young spinach leaves actively produce oxalate. A series of labeled compounds was supplied to each of these tissues to determine the extent of conversion to oxalate. Similar results were obtained with the 2 tissues except that in the leaf tissue glyoxylate and glycolate were outstandingly good precursors. Carbon from glucose, acetate, and particularly from some acids of the tricarboxylic acid cycle was recovered in oxalate. Extracts from both tissues were found to contain an enzyme which converts oxaloacetate to oxalate and acetate. The enzyme was partially purified and some of its properties are described. A pathway of oxalate synthesis which does not include glycolate or its oxidase is therefore proposed. PMID:16656975

  10. Forecasting annual aboveground net primary production in the intermountain west

    Technology Transfer Automated Retrieval System (TEKTRAN)

    For many land manager’s annual aboveground net primary production, or plant growth, is a key factor affecting business success, profitability and each land manager's ability to successfully meet land management objectives. The strategy often utilized for forecasting plant growth is to assume every y...

  11. Using Tissue Culture To Investigate Plant Cell Differentiation and Dedifferentiation.

    ERIC Educational Resources Information Center

    Bozzone, Donna M.

    1997-01-01

    Describes an experimental project that uses plant tissue culture techniques to examine cell differentiation in the carrot. Allows students to gain experience in some important techniques and to explore fundamental questions about cell differentiation. (DDR)

  12. Species and tissue type regulate long-term decomposition of brackish marsh plants grown under elevated CO2 conditions

    NASA Astrophysics Data System (ADS)

    Jones, Joshua A.; Cherry, Julia A.; McKee, Karen L.

    2016-02-01

    Organic matter accumulation, the net effect of plant production and decomposition, contributes to vertical soil accretion in coastal wetlands, thereby playing a key role in whether they keep pace with sea-level rise. Any factor that affects decomposition may affect wetland accretion, including atmospheric CO2 concentrations. Higher CO2 can influence decomposition rates by altering plant tissue chemistry or by causing shifts in plant species composition or biomass partitioning. A combined greenhouse-field experiment examined how elevated CO2 affected plant tissue chemistry and subsequent decomposition of above- and belowground tissues of two common brackish marsh species, Schoenoplectus americanus (C3) and Spartina patens (C4). Both species were grown in monoculture and in mixture under ambient (350-385 μL L-1) or elevated (ambient + 300 μL L-1) atmospheric CO2 conditions, with all other growth conditions held constant, for one growing season. Above- and belowground tissues produced under these treatments were decomposed under ambient field conditions in a brackish marsh in the Mississippi River Delta, USA. Elevated CO2 significantly reduced nitrogen content of S. americanus, but not sufficiently to affect subsequent decomposition. Instead, long-term decomposition (percent mass remaining after 280 d) was controlled by species composition and tissue type. Shoots of S. patens had more mass remaining (41 ± 2%) than those of S. americanus (12 ± 2%). Belowground material decomposed more slowly than that placed aboveground (62 ± 1% vs. 23 ± 3% mass remaining), but rates belowground did not differ between species. Increases in atmospheric CO2 concentration will likely have a greater effect on overall decomposition in this brackish marsh community through shifts in species dominance or biomass allocation than through effects on tissue chemistry. Consequent changes in organic matter accumulation may alter marsh capacity to accommodate sea-level rise through vertical

  13. Development of germ-free plants and tissue culture

    NASA Technical Reports Server (NTRS)

    Venketeswaran, S.

    1973-01-01

    The botanical program is reported for experiments performed at the Lunar Receiving Laboratory. Papers prepared during this program are listed. The studies reported include: tissues cultured on various mediums, nutritional studies, preparation of plant cultures for Apollo 15, and pine tissue cultures.

  14. Prediction of atmospheric δ13CO2 using fossil plant tissues

    SciTech Connect

    A. Hope Jahren; Arens, Nan Crystal; Harbeson, Stephanie A.

    2008-06-30

    To summarize the content: we presented the results of laboratory experiments designed to quantify the relationship between plant tissue δ13C and δ13CO2 values under varying environmental conditions, including differential pCO2 ranging from 1 to 3 times today’s levels. As predicted, plants grown under elevated pCO2 showed increased average biomass compared to controls grown at the same temperature. Across a very large range in δ13Ca (≈ 24 ‰) and pCO2 (≈ 740 ppmv) we observed a consistent correlation between δ13Ca and δ13Cp (p<0.001). We show an average isotopic depletion of -25.4 ‰ for above-ground tissue and -23.2 ‰ for below-ground tissue of Raphanus sativus L. relative to the composition of the atmosphere under which it formed. For both above- and below-ground tissue, grown at both ~23 °C and ~29 °C, correlation was strong and significant (r2 ≥ 0.98, p<0.001); variation in pCO2 level had little or no effect on this relationship.

  15. Consequences of long-term severe industrial pollution for aboveground carbon and nitrogen pools in northern taiga forests at local and regional scales.

    PubMed

    Manninen, Sirkku; Zverev, Vitali; Bergman, Igor; Kozlov, Mikhail V

    2015-12-01

    Boreal coniferous forests act as an important sink for atmospheric carbon dioxide. The overall tree carbon (C) sink in the forests of Europe has increased during the past decades, especially due to management and elevated nitrogen (N) deposition; however, industrial atmospheric pollution, primarily sulphur dioxide and heavy metals, still negatively affect forest biomass production at different spatial scales. We report local and regional changes in forest aboveground biomass, C and N concentrations in plant tissues, and C and N pools caused by long-term atmospheric emissions from a large point source, the nickel-copper smelter in Monchegorsk, in north-western Russia. An increase in pollution load (assessed as Cu concentration in forest litter) caused C to increase in foliage but C remained unchanged in wood, while N decreased in foliage and increased in wood, demonstrating strong effects of pollution on resource translocation between green and woody tissues. The aboveground C and N pools were primarily governed by plant biomass, which strongly decreased with an increase in pollution load. In our study sites (located 1.6-39.7 km from the smelter) living aboveground plant biomass was 76 to 4888 gm(-2), and C and N pools ranged 35-2333 g C m(-2) and 0.5-35.1 g N m(-2), respectively. We estimate that the aboveground plant biomass is reduced due to chronic exposure to industrial air pollution over an area of about 107,200 km2, and the total (aboveground and belowground) loss of phytomass C stock amounts to 4.24×10(13) g C. Our results emphasize the need to account for the overall impact of industrial polluters on ecosystem C and N pools when assessing the C and N dynamics in northern boreal forests because of the marked long-term negative effects of their emissions on structure and productivity of plant communities. PMID:26254064

  16. Commercializing plant tissue culture processes: economics, problems and prospects

    SciTech Connect

    Sahai, O.; Knuth, M.

    1985-03-01

    Novel tissue culture techniques and a range of process schemes may be considered for commercial production of plant derived drugs, chemicals, flavors and cosmetics. Plant cell immobilization, in conjunction with strain selection and product leakage, represents a major technological advancement, with significant economic implications. Conventional batch processes produce high value products at low production capacities, whereas continuous biocatalytic processes can potentially enable production of plant derived chemicals in the $20-$25/kg price range.

  17. Comparative Proteomics of Cannabis sativa Plant Tissues

    PubMed Central

    Raharjo, Tri J.; Widjaja, Ivy; Roytrakul, Sittiruk; Verpoorte, Robert

    2004-01-01

    Comparative proteomics of leaves, flowers, and glands of Cannabis sativa have been used to identify specific tissue-expressed proteins. These tissues have significantly different levels of cannabinoids. Cannabinoids accumulate primarily in the glands but can also be found in flowers and leaves. Proteins extracted from glands, flowers, and leaves were separated using two-dimensional gel electrophoresis. Over 800 protein spots were reproducibly resolved in the two-dimensional gels from leaves and flowers. The patterns of the gels were different and little correlation among the proteins could be observed. Some proteins that were only expressed in flowers were chosen for identification by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and peptide mass fingerprint database searching. Flower and gland proteomes were also compared, with the finding that less then half of the proteins expressed in flowers were also expressed in glands. Some selected gland protein spots were identified: F1D9.26-unknown prot. (Arabidopsis thaliana), phospholipase D beta 1 isoform 1a (Gossypium hirsutum), and PG1 (Hordeum vulgare). Western blotting was employed to identify a polyketide synthase, an enzyme believed to be involved in cannabinoid biosynthesis, resulting in detection of a single protein. PMID:15190082

  18. Triacylglycerol Metabolism, Function, and Accumulation in Plant Vegetative Tissues.

    PubMed

    Xu, Changcheng; Shanklin, John

    2016-04-29

    Oils in the form of triacylglycerols are the most abundant energy-dense storage compounds in eukaryotes, and their metabolism plays a key role in cellular energy balance, lipid homeostasis, growth, and maintenance. Plants accumulate oils primarily in seeds and fruits. Plant oils are used for food and feed and, increasingly, as feedstocks for biodiesel and industrial chemicals. Although plant vegetative tissues do not accumulate significant levels of triacylglycerols, they possess a high capacity for their synthesis, storage, and metabolism. The development of plants that accumulate oil in vegetative tissues presents an opportunity for expanded production of triacylglycerols as a renewable and sustainable bioenergy source. Here, we review recent progress in the understanding of triacylglycerol synthesis, turnover, storage, and function in leaves and discuss emerging genetic engineering strategies targeted at enhancing triacylglycerol accumulation in biomass crops. Such plants could potentially be modified to produce oleochemical feedstocks or nutraceuticals. PMID:26845499

  19. Different bacterial communities in heat and gamma irradiation treated replant disease soils revealed by 16S rRNA gene analysis – contribution to improved aboveground apple plant growth?

    PubMed Central

    Yim, Bunlong; Winkelmann, Traud; Ding, Guo-Chun; Smalla, Kornelia

    2015-01-01

    Replant disease (RD) severely affects apple production in propagation tree nurseries and in fruit orchards worldwide. This study aimed to investigate the effects of soil disinfection treatments on plant growth and health in a biotest in two different RD soil types under greenhouse conditions and to link the plant growth status with the bacterial community composition at the time of plant sampling. In the biotest performed we observed that the aboveground growth of apple rootstock M26 plants after 8 weeks was improved in the two RD soils either treated at 50°C or with gamma irradiation compared to the untreated RD soils. Total community DNA was extracted from soil loosely adhering to the roots and quantitative real-time PCR revealed no pronounced differences in 16S rRNA gene copy numbers. 16S rRNA gene-based bacterial community analysis by denaturing gradient gel electrophoresis (DGGE) and 454-pyrosequencing revealed significant differences in the bacterial community composition even after 8 weeks of plant growth. In both soils, the treatments affected different phyla but only the relative abundance of Acidobacteria was reduced by both treatments. The genera Streptomyces, Bacillus, Paenibacillus, and Sphingomonas had a higher relative abundance in both heat treated soils, whereas the relative abundance of Mucilaginibacter, Devosia, and Rhodanobacter was increased in the gamma-irradiated soils and only the genus Phenylobacterium was increased in both treatments. The increased abundance of genera with potentially beneficial bacteria, i.e., potential degraders of phenolic compounds might have contributed to the improved plant growth in both treatments. PMID:26635733

  20. 3D simulation of plant and living tissue superficial lesions

    NASA Astrophysics Data System (ADS)

    Bratchenko, Ivan A.; Sindyaeva, Alexandra R.; Zakharov, Valery P.

    2008-06-01

    The analytic schemes of calculated absorbed and scattered radiation spatial distribution in multilayer plant and living tissues and diagnostic of their physical state are presented. The correct realization of these tasks was obtained with 3D Monte Carlo simulation of optical radiation propagation through multiple scattering medium in TracePro environment. Analysis of simulation data was made by differential backscattering method, which allows to investigate general backscattered radiation dependences on optical and geometrical parameters of living tissue. It was shown that obtained results formed the basis for developing an algorithm of optical superficial inhomogeneous registration and spatial localization. Such diagnosis can be executed in tissues of any arbitrary surface structure. Designed scheme is intended to utilize in contactless macro diagnostics device. The same approach was used for simulation of optical spectra of healthy and diseased virtual leaves for plant tissue pathological changes revealing.

  1. The role of silicon in plant tissue culture.

    PubMed

    Sivanesan, Iyyakkannu; Park, Se Won

    2014-01-01

    Growth and morphogenesis of in vitro cultures of plant cells, tissues, and organs are greatly influenced by the composition of the culture medium. Mineral nutrients are necessary for the growth and development of plants. Several morpho-physiological disorders such as hooked leaves, hyperhydricity, fasciation, and shoot tip necrosis are often associated with the concentration of inorganic nutrient in the tissue culture medium. Silicon (Si) is the most abundant mineral element in the soil. The application of Si has been demonstrated to be beneficial for growth, development and yield of various plants and to alleviate various stresses including nutrient imbalance. Addition of Si to the tissue culture medium improves organogenesis, embryogenesis, growth traits, morphological, anatomical, and physiological characteristics of leaves, enhances tolerance to low temperature and salinity, protects cells and against metal toxicity, prevents oxidative phenolic browning and reduces the incidence of hyperhydricity in various plants. Therefore, Si possesses considerable potential for application in a wide range of plant tissue culture studies such as cryopreservation, organogenesis, micropropagation, somatic embryogenesis and secondary metabolites production. PMID:25374578

  2. The role of silicon in plant tissue culture

    PubMed Central

    Sivanesan, Iyyakkannu; Park, Se Won

    2014-01-01

    Growth and morphogenesis of in vitro cultures of plant cells, tissues, and organs are greatly influenced by the composition of the culture medium. Mineral nutrients are necessary for the growth and development of plants. Several morpho-physiological disorders such as hooked leaves, hyperhydricity, fasciation, and shoot tip necrosis are often associated with the concentration of inorganic nutrient in the tissue culture medium. Silicon (Si) is the most abundant mineral element in the soil. The application of Si has been demonstrated to be beneficial for growth, development and yield of various plants and to alleviate various stresses including nutrient imbalance. Addition of Si to the tissue culture medium improves organogenesis, embryogenesis, growth traits, morphological, anatomical, and physiological characteristics of leaves, enhances tolerance to low temperature and salinity, protects cells and against metal toxicity, prevents oxidative phenolic browning and reduces the incidence of hyperhydricity in various plants. Therefore, Si possesses considerable potential for application in a wide range of plant tissue culture studies such as cryopreservation, organogenesis, micropropagation, somatic embryogenesis and secondary metabolites production. PMID:25374578

  3. Transport of root-derived CO2 via the transpiration stream affects aboveground tree physiology

    NASA Astrophysics Data System (ADS)

    Bloemen, J.; McGuire, M. A.; Aubrey, D. P.; Teskey, R. O.; Steppe, K.

    2012-04-01

    Recent research on soil CO2 efflux has shown that belowground autotrophic respiration is largely underestimated using classical net CO2 flux measurements. Aubrey & Teskey (2009) found that in forest ecosystems a substantial portion of the CO2 released from root respiration remained within the root system and was transported aboveground in the stem via the transpiration stream. The magnitude of this upward movement of CO2 from belowground tissues suggested important implications for how we measure above- and belowground respiration. If a considerable fraction of root-respired CO2 is transported aboveground, where it might be fixed in woody and leaf tissues, then we are routinely underestimating the amount of C needed to sustain belowground tissues. In this study, we infused 13C labeled water into the base of field-grown poplar trees as a surrogate for root-respired CO2 to investigate the possible role of root-derived CO2 as substrate for carbon fixation. The label was transported upwards from the base of the tree toward the top. During its ascent, the 13C label was removed from the transpiration stream and fixed by chlorophyll-containing woody (young bark and xylem) and leaf (petiole) tissues. Moreover, based on 13C analysis of gas samples, we observed that up to 88 ± 0.10 % of the label applied was lost to the atmosphere by stem and branch efflux higher in the trees. Given that one-half of root-respired CO2 may follow this internal flux pathway (Aubrey & Teskey, 2009), we calculated that up to 44% of the root-respired CO2 could diffuse to the atmosphere once transported to the stem and branches. Thus, a large portion of CO2 that diffuses out of aboveground tissues may actually result from root respiration. Our results show that CO2 originating belowground can be transported internally to aboveground parts of trees, where it will have an important impact on tree physiology. Internal transport of CO2 indicates that the gas exchange approach to estimating above- and

  4. Effect of lunar materials on plant tissue culture.

    NASA Technical Reports Server (NTRS)

    Walkinshaw, C. H.; Venketeswaran, S.; Baur, P. S.; Croley, T. E.; Scholes, V. E.; Weete, J. D.; Halliwell, R. S.; Hall, R. H.

    1973-01-01

    Lunar material collected during the Apollo 11, 12, 14, and 15 missions has been used to treat 12 species of higher plant tissue cultures. Biochemical and morphological studies have been conducted on several of these species. Tobacco tissue cultures treated with 0.22 g of lunar material exhibited increased greening more complex chloroplasts, less cytoplasmic vacuolation and greater vesiculation. Pine tissue cultures reacted to treatment by an increased deposition of tannin-like materials. The percentage of dry weight and soluble protein was increased in cultures treated with either lunar or terrestrial rock materials.

  5. Constitutive and induced defenses to herbivory in above- and belowground plant tissues.

    PubMed

    Kaplan, Ian; Halitschke, Rayko; Kessler, André; Sardanelli, Sandra; Denno, Robert F

    2008-02-01

    A recent surge in attention devoted to the ecology of soil biota has prompted interest in quantifying similarities and differences between interactions occurring in above- and belowground communities. Furthermore, linkages that interconnect the dynamics of these two spatially distinct ecosystems are increasingly documented. We use a similar approach in the context of understanding plant defenses to herbivory, including how they are allocated between leaves and roots (constitutive defenses), and potential cross-system linkages (induced defenses). To explore these issues we utilized three different empirical approaches. First, we manipulated foliar and root herbivory on tobacco (Nicotiana tabacum) and measured changes in the secondary chemistry of above- and belowground tissues. Second, we reviewed published studies that compared levels of secondary chemistry between leaves and roots to determine how plants distribute putative defense chemicals across the above- and belowground systems. Last, we used meta-analysis to quantify the impact of induced responses across plant tissue types. In the tobacco system, leaf-chewing insects strongly induced higher levels of secondary metabolites in leaves but had no impact on root chemistry. Nematode root herbivores, however, elicited changes in both leaves and roots. Virtually all secondary chemicals measured were elevated in nematode-induced galls, whereas the impact of root herbivory on foliar chemistry was highly variable and depended on where chemicals were produced within the plant. Importantly, nematodes interfered with aboveground metabolites that have biosynthetic sites located in roots (e.g., nicotine) but had the opposite effect (i.e., nematodes elevated foliar expression) on chemicals produced in shoots (e.g., phenolics and terpenoids). Results from our literature review suggest that, overall, constitutive defense levels are extremely similar when comparing leaves with roots, although certain chemical classes (e

  6. MICROWAVE IRRADIATION FOR RAPID KILLING AND FIXING OF PLANT TISSUE

    EPA Science Inventory

    Irradiation by microwaves allow for rapid billing and fixing of plant tissue, with excellent cellular integrity for histological examination. One or two exposures to microwaves for three seconds in formalin/acetic acid/alcohol gave good preservation of nuclei, chloroplasts and ot...

  7. Analysis of chemical components from plant tissue samples

    NASA Technical Reports Server (NTRS)

    Laseter, J. L.

    1972-01-01

    Information is given on the type and concentration of sterols, free fatty acids, and total fatty acids in plant tissue samples. All samples were analyzed by gas chromatography and then by gas chromatography-mass spectrometry combination. In each case the mass spectral data was accumulated as a computer printout and plot. Typical gas chromatograms are included as well as tables describing test results.

  8. Mass recovery methods for trichloroethylene in plant tissue.

    SciTech Connect

    Gopalakrishnan, G.; Negri, M. C.; Werth, C. J.; Energy Systems; Univ. of Illionis

    2009-06-01

    Monitoring expenses form a significant fraction of the costs associated with remediation of contaminated soil and groundwater sites. A novel monitoring method that could result in significant cost savings is the use of plants as monitoring devices; previous work indicates that plant tissue samples, especially trunk (core) and branch samples, can be used to delineate soil and groundwater plumes at phytoremediation sites. An important factor in reducing the uncertainty associated with this sampling method is development of a technique to analyze, both consistently and accurately, the chemicals stored in plant tissue samples. The present research presents a simple, robust, and inexpensive technique to recover most of the contaminant in plant branch tissue, irrespective of the age or species of the plant. Trichloroethylene (TCE) was the chemical analyzed. A number of headspace and solvent extraction techniques in the literature were evaluated, including headspace extraction at different incubation times and temperatures and solvent extraction using hexane or hot methanol. Extraction using hot methanol was relatively fast, simple, and reliable; this method recovered more than 89% of the TCE present in branches of five different tree species.

  9. Dynamics of long-distance signaling via plant vascular tissues.

    PubMed

    Notaguchi, Michitaka; Okamoto, Satoru

    2015-01-01

    Plant vascular systems are constructed by specific cell wall modifications through which cells are highly specialized to make conduits for water and nutrients. Xylem vessels are formed by thickened cell walls that remain after programmed cell death, and serve as water conduits from the root to the shoot. In contrast, phloem tissues consist of a complex of living cells, including sieve tube elements and their neighboring companion cells, and translocate photosynthetic assimilates from mature leaves to developing young tissues. Intensive studies on the content of vascular flow fluids have unveiled that plant vascular tissues transport various types of gene product, and the transport of some provides the molecular basis for the long-distance communications. Analysis of xylem sap has demonstrated the presence of proteins in the xylem transpiration stream. Recent studies have revealed that CLE and CEP peptides secreted in the roots are transported to above ground via the xylem in response to plant-microbe interaction and soil nitrogen starvation, respectively. Their leucine-rich repeat transmembrane receptors localized in the shoot phloem are required for relaying the signal from the shoot to the root. These findings well-fit to the current scenario of root-to-shoot-to-root feedback signaling, where peptide transport achieves the root-to-shoot signaling, the first half of the signaling process. Meanwhile, it is now well-evidenced that proteins and a range of RNAs are transported via the phloem translocation system, and some of those can exert their physiological functions at their destinations, including roots. Thus, plant vascular systems may serve not only as conduits for the translocation of essential substances but also as long-distance communication pathways that allow plants to adapt to changes in internal and external environments at the whole plant level. PMID:25852714

  10. Effective half-lives of ¹³⁷Cs in giant butterbur and field horsetail, and the distribution differences of potassium and ¹³⁷Cs in aboveground tissue parts.

    PubMed

    Tagami, Keiko; Uchida, Shigeo

    2015-03-01

    Concentrations of (137)Cs and (40)K in different tissues of edible wild herbaceous plants, that is, leaf blade and petiole for giant butterbur (Petasites japonicas (Siebold et Zucc.) Maxim.), and leaf, stem and strobilus for fertile shoot of field horsetail (Equisetum arvense L.) were measured in 2012-2014 to clarify the effect in Japan from the Fukushima Daiichi Nuclear Power Plant accident. The concentrations of (137)Cs decreased with time with effective half-lives of ca. 450 d and 360 d for giant butterbur and field horsetail, respectively. The ANOVA test revealed that (40)K and (137)Cs distributions in leaf blade and petiole for giant butterbur and leaf and stem for field horsetail were different. Therefore, other plants, leaf and stem for Japanese knotweed (Fallopia japonica (Houtt.) Ronse Decr.) and Canada goldenrod (Solidago canadensis L.), and leaf blade and petiole for gingko (Ginkgo biloba L.) and Someiyoshino cherry (Cerasus × yedoensis (Matsum.) A.V.Vassil. 'Somei-yoshino') were collected from the same sampling field and their (137)Cs and (40)K concentrations were compared to those in the giant butterbur and field horsetail parts. For (137)Cs, concentrations in leaf blade and leaf parts were 1.1-6.0 times higher than those in petiole and stem parts for all six plants. On the other hand, (40)K concentrations in leaf blade and leaf parts were 0.40-0.97 of those observed in petiole and stem parts. Discrimination ratios of (40)K/(137)Cs of leaf blade to petiole or leaf to stem were then calculated and they ranged from 0.09 to 0.57. These results suggested that Cs and K did not behave similarly in these plants. Thus, to understand the radiocesium fate in plants, K measurement results should not be used as an analog for Cs behavior although Cs is known to have a similar chemical reactivity to that of K. PMID:25588954

  11. Defined media for plant tissue culture: Final report

    SciTech Connect

    Good, N.E.

    1986-01-01

    This grant was for the purpose of developing improved plant tissue culture media. The rationale was to introduce the use of low pKa hydrogen ion buffers to stabilize pH and to introduce the use of slow release forms of the plant hormones, auxin and cytokinin, to provide the tissues with a constant supply of these essential factors. The zwittionic buffer, MES, proved useful for pH stabilization, while a wide range of indoleacetylamino acids provided a wide range of levels of available amino acids with consequent different levels of development of shoots, roots or callus. In general, some free indoleacetic acid in addition to the conjugate seemed necessary for organogenesis, but this phenomenon depended very much on the level of cytokinin. Time did not permit us to make any significant progress in the development of slow-release forms of cytokinins. 2 figs.

  12. Mechanical behaviour of plant tissues: composite materials or structures?

    PubMed

    Spatz, H; Köhler, L; Niklas, K J

    1999-12-01

    The mechanical characteristics of the strengthening tissue of young axes of Aristolochia macrophylla were studied in successive loading-unloading cycles in tension. Elastic, viscoelastic and plastic deformations could be distinguished. After the first cycle, the material was in a state different from its original state, to which it returned only partially and/or slowly. Internal 'microstructural' prestresses are considered as an explanation for the mechanical behaviour seen in Aristolochia macrophylla and several other plants. PMID:10562508

  13. Plant-Derived Human Collagen Scaffolds for Skin Tissue Engineering

    PubMed Central

    Willard, James J.; Drexler, Jason W.; Das, Amitava; Roy, Sashwati; Shilo, Shani; Shoseyov, Oded

    2013-01-01

    Tissue engineering scaffolds are commonly formed using proteins extracted from animal tissues, such as bovine hide. Risks associated with the use of these materials include hypersensitivity and pathogenic contamination. Human-derived proteins lower the risk of hypersensitivity, but possess the risk of disease transmission. Methods engineering recombinant human proteins using plant material provide an alternate source of these materials without the risk of disease transmission or concerns regarding variability. To investigate the utility of plant-derived human collagen (PDHC) in the development of engineered skin (ES), PDHC and bovine hide collagen were formed into tissue engineering scaffolds using electrospinning or freeze-drying. Both raw materials were easily formed into two common scaffold types, electrospun nonwoven scaffolds and lyophilized sponges, with similar architectures. The processing time, however, was significantly lower with PDHC. PDHC scaffolds supported primary human cell attachment and proliferation at an equivalent or higher level than the bovine material. Interleukin-1 beta production was significantly lower when activated THP-1 macrophages where exposed to PDHC electrospun scaffolds compared to bovine collagen. Both materials promoted proper maturation and differentiation of ES. These data suggest that PDHC may provide a novel source of raw material for tissue engineering with low risk of allergic response or disease transmission. PMID:23298216

  14. Plant-derived human collagen scaffolds for skin tissue engineering.

    PubMed

    Willard, James J; Drexler, Jason W; Das, Amitava; Roy, Sashwati; Shilo, Shani; Shoseyov, Oded; Powell, Heather M

    2013-07-01

    Tissue engineering scaffolds are commonly formed using proteins extracted from animal tissues, such as bovine hide. Risks associated with the use of these materials include hypersensitivity and pathogenic contamination. Human-derived proteins lower the risk of hypersensitivity, but possess the risk of disease transmission. Methods engineering recombinant human proteins using plant material provide an alternate source of these materials without the risk of disease transmission or concerns regarding variability. To investigate the utility of plant-derived human collagen (PDHC) in the development of engineered skin (ES), PDHC and bovine hide collagen were formed into tissue engineering scaffolds using electrospinning or freeze-drying. Both raw materials were easily formed into two common scaffold types, electrospun nonwoven scaffolds and lyophilized sponges, with similar architectures. The processing time, however, was significantly lower with PDHC. PDHC scaffolds supported primary human cell attachment and proliferation at an equivalent or higher level than the bovine material. Interleukin-1 beta production was significantly lower when activated THP-1 macrophages where exposed to PDHC electrospun scaffolds compared to bovine collagen. Both materials promoted proper maturation and differentiation of ES. These data suggest that PDHC may provide a novel source of raw material for tissue engineering with low risk of allergic response or disease transmission. PMID:23298216

  15. Classification of explosives transformation products in plant tissue

    SciTech Connect

    Larson, S.L.; Jones, R.P. . Waterways Experiment Station); Escalon, L.; Parker, D. )

    1999-06-01

    Explosives contamination in surface or groundwater used for the irrigation of food crops and phytoremediation of explosives-contaminated soil or water using plant-assisted biodegradation have brought about concerns as to the fate of explosives in plants. Liquid scintillation counting, high-performance liquid chromatography, and gel permeation chromatography were utilized to characterize explosives (hexahydro-1,3,5-trinitro-1,3,5-triazine and trinitrotoluene) and their metabolites in plant tissues obtained from three separate studies. Analyzing tissues of yellow nutsedge (Cyperus esculentus), corn (Zea mays), lettuce (Lacuta sativa), tomato (Lyopersicum esculentum), radish (Raphanus sativus), and parrot feather (Myriophyllum aquaticum) from three studies where exposure to explosives at nontoxic levels occurred showed that extensive transformation of the explosive contaminant occurred, variations were noted in uptake and transformation between terrestrial and aquatic plants, the products had significantly higher polarity and water solubility than the parent compounds, and the molecular sizes of the transformation products were significantly greater than those of the parent compounds.

  16. Species and tissue type regulate long-term decomposition of brackish marsh plants grown under elevated CO2 conditions

    USGS Publications Warehouse

    Jones, Joshua A; Cherry, Julia A; Mckee, Karen L.

    2016-01-01

    Organic matter accumulation, the net effect of plant production and decomposition, contributes to vertical soil accretion in coastal wetlands, thereby playing a key role in whether they keep pace with sea-level rise. Any factor that affects decomposition may affect wetland accretion, including atmospheric CO2 concentrations. Higher CO2 can influence decomposition rates by altering plant tissue chemistry or by causing shifts in plant species composition or biomass partitioning. A combined greenhouse-field experiment examined how elevated CO2 affected plant tissue chemistry and subsequent decomposition of above- and belowground tissues of two common brackish marsh species, Schoenoplectus americanus (C3) and Spartina patens (C4). Both species were grown in monoculture and in mixture under ambient (350-385 μL L-1) or elevated (ambient + 300 μL L-1) atmospheric CO2 conditions, with all other growth conditions held constant, for one growing season. Above- and belowground tissues produced under these treatments were decomposed under ambient field conditions in a brackish marsh in the Mississippi River Delta, USA. Elevated CO2 significantly reduced nitrogen content of S. americanus, but not sufficiently to affect subsequent decomposition. Instead, long-term decomposition (percent mass remaining after 280 d) was controlled by species composition and tissue type. Shoots of S. patens had more mass remaining (41 ± 2%) than those of S. americanus (12 ± 2 %). Belowground material decomposed more slowly than that placed aboveground (62 ± 1% vs. 23 ± 3% mass remaining), but rates belowground did not differ between species. Increases in atmospheric CO2concentration will likely have a greater effect on overall decomposition in this brackish marsh community through shifts in species dominance or biomass allocation than through effects on tissue chemistry. Consequent changes in organic matter accumulation may alter marsh capacity to accommodate sea-level rise

  17. New insights into Fe localization in plant tissues.

    PubMed

    Roschzttardtz, Hannetz; Conéjéro, Geneviève; Divol, Fanchon; Alcon, Carine; Verdeil, Jean-Luc; Curie, Catherine; Mari, Stéphane

    2013-01-01

    Deciphering cellular iron (Fe) homeostasis requires having access to both quantitative and qualitative information on the subcellular pools of Fe in tissues and their dynamics within the cells. We have taken advantage of the Perls/DAB Fe staining procedure to perform a systematic analysis of Fe distribution in roots, leaves and reproductive organs of the model plant Arabidopsis thaliana, using wild-type and mutant genotypes affected in iron transport and storage. Roots of soil-grown plants accumulate iron in the apoplast of the central cylinder, a pattern that is strongly intensified when the citrate effluxer FRD3 is not functional, thus stressing the importance of citrate in the apoplastic movement of Fe. In leaves, Fe level is low and only detected in and around vascular tissues. In contrast, Fe staining in leaves of iron-treated plants extends in the surrounding mesophyll cells where Fe deposits, likely corresponding to Fe-ferritin complexes, accumulate in the chloroplasts. The loss of ferritins in the fer1,3,4 triple mutant provoked a massive accumulation of Fe in the apoplastic space, suggesting that in the absence of iron buffering in the chloroplast, cells activate iron efflux and/or repress iron influx to limit the amount of iron in the cell. In flowers, Perls/DAB staining has revealed a major sink for Fe in the anthers. In particular, developing pollen grains accumulate detectable amounts of Fe in small-size intracellular bodies that aggregate around the vegetative nucleus at the binuclear stage and that were identified as amyloplasts. In conclusion, using the Perls/DAB procedure combined to selected mutant genotypes, this study has established a reliable atlas of Fe distribution in the main Arabidopsis organs, proving and refining long-assumed intracellular locations and uncovering new ones. This "iron map" of Arabidopsis will serve as a basis for future studies of possible actors of iron movement in plant tissues and cell compartments. PMID:24046774

  18. New insights into Fe localization in plant tissues

    PubMed Central

    Roschzttardtz, Hannetz; Conéjéro, Geneviève; Divol, Fanchon; Alcon, Carine; Verdeil, Jean-Luc; Curie, Catherine; Mari, Stéphane

    2013-01-01

    Deciphering cellular iron (Fe) homeostasis requires having access to both quantitative and qualitative information on the subcellular pools of Fe in tissues and their dynamics within the cells. We have taken advantage of the Perls/DAB Fe staining procedure to perform a systematic analysis of Fe distribution in roots, leaves and reproductive organs of the model plant Arabidopsis thaliana, using wild-type and mutant genotypes affected in iron transport and storage. Roots of soil-grown plants accumulate iron in the apoplast of the central cylinder, a pattern that is strongly intensified when the citrate effluxer FRD3 is not functional, thus stressing the importance of citrate in the apoplastic movement of Fe. In leaves, Fe level is low and only detected in and around vascular tissues. In contrast, Fe staining in leaves of iron-treated plants extends in the surrounding mesophyll cells where Fe deposits, likely corresponding to Fe-ferritin complexes, accumulate in the chloroplasts. The loss of ferritins in the fer1,3,4 triple mutant provoked a massive accumulation of Fe in the apoplastic space, suggesting that in the absence of iron buffering in the chloroplast, cells activate iron efflux and/or repress iron influx to limit the amount of iron in the cell. In flowers, Perls/DAB staining has revealed a major sink for Fe in the anthers. In particular, developing pollen grains accumulate detectable amounts of Fe in small-size intracellular bodies that aggregate around the vegetative nucleus at the binuclear stage and that were identified as amyloplasts. In conclusion, using the Perls/DAB procedure combined to selected mutant genotypes, this study has established a reliable atlas of Fe distribution in the main Arabidopsis organs, proving and refining long-assumed intracellular locations and uncovering new ones. This “iron map” of Arabidopsis will serve as a basis for future studies of possible actors of iron movement in plant tissues and cell compartments. PMID:24046774

  19. The role of activated charcoal in plant tissue culture.

    PubMed

    Thomas, T Dennis

    2008-01-01

    Activated charcoal has a very fine network of pores with large inner surface area on which many substances can be adsorbed. Activated charcoal is often used in tissue culture to improve cell growth and development. It plays a critical role in micropropagation, orchid seed germination, somatic embryogenesis, anther culture, synthetic seed production, protoplast culture, rooting, stem elongation, bulb formation etc. The promotary effects of AC on morphogenesis may be mainly due to its irreversible adsorption of inhibitory compounds in the culture medium and substancially decreasing the toxic metabolites, phenolic exudation and brown exudate accumulation. In addition to this activated charcoal is involved in a number of stimulatory and inhibitory activities including the release of substances naturally present in AC which promote growth, alteration and darkening of culture media, and adsorption of vitamins, metal ions and plant growth regulators, including abscisic acid and gaseous ethylene. The effect of AC on growth regulator uptake is still unclear but some workers believe that AC may gradually release certain adsorbed products, such as nutrients and growth regulators which become available to plants. This review focuses on the various roles of activated charcoal in plant tissue culture and the recent developments in this area. PMID:18786626

  20. Plant tissue analysis for explosive compounds in phytoremediation and phytoforensics.

    PubMed

    Karnjanapiboonwong, Adcharee; Mu, Ruipu; Yuan, Yuan; Shi, Honglan; Ma, Yinfa; Burken, Joel G

    2012-01-01

    Plant tissue analysis methods were evaluated for six explosive compounds to assess uptake and phytoforensic methods development to quantify explosives in plant to obtain the plant data for the evaluation of explosive contamination in soil and groundwater. Four different solvent mixtures containing acetonitrile or methanol were tested at variable extraction ratios to compare the extraction efficiency for six explosive compounds: 2,4,6-trinitrotoluene (TNT), pentaerythritoltetranitrate (PETN), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), 2-amino-4,6-dinitrotoluene (2ADNT), and 2,4-Dinitroanisole (DNAN), in Laurel Willow (Salix pentandra) stem and range grass Big Bluestem (Andropogon gerardii) using LC-MS/MS. Plant tissues were spiked with 500 ng/g of explosives and extracted using ultrasonically-assisted solvent extraction. With the ratio of fresh plant mass to solvent volume of 1:20 for willow and 1:40 for big bluestem grass, results indicated that all explosives in willow except HMX were extracted at higher than 73.3% by using 20 mL of methanol, 50:50 (v/v) methanol:water, or acetonitrile, whereas HMX was extracted with the highest recovery of 61.3% by 20 mL of acetonitrile. In big bluestem grass, the most effective solvents were 20 mL of either methanol or 50:50 (v/v) methanol:water for PETN extraction with a recovery of higher than 101.2% and 20 mL of 50:50 (v/v) methanol:water for HMX, RDX, TNT, 2ADNT, and DNAN extraction with a recovery of 83.8%, 104.4%, 97.5%, 80.7%, and 108.2%, respectively. However, unlike methanol and acetonitrile, 50:50 (v/v) methanol:water provided no problem of leading or split peak in chromatogram; therefore, it was preferred in the test and performed a method validation. Results indicated that 50:50 (v/v) methanol:water provided good repeatability and recovery and method detection limits at 0.5-20 ng/g fresh weight or 8.8-61.3 ng/g dry weight. Overall, results suggested that

  1. High resolution mass spectrometry imaging of plant tissues: towards a plant metabolite atlas.

    PubMed

    Bhandari, Dhaka Ram; Wang, Qing; Friedt, Wolfgang; Spengler, Bernhard; Gottwald, Sven; Römpp, Andreas

    2015-11-21

    Mass spectrometry (MS) imaging provides spatial and molecular information for a wide range of compounds. This tool can be used to investigate metabolic changes in plant physiology and environmental interactions. A major challenge in our study was to prepare tissue sections that were compatible with high spatial resolution analysis and therefore dedicated sample preparation protocols were established and optimized for the physicochemical properties of all major plant organs. We combined high spatial resolution (5 μm), in order to detect cellular features, and high mass accuracy (<2 ppm root mean square error), for molecular specificity. Mass spectrometry imaging experiments were performed in positive and negative ion mode. Changes in metabolite patterns during plant development were investigated for germination of oilseed rape. The detailed localization of more than 90 compounds allowed assignment to metabolic processes and indicated possible functions in plant tissues. The 'untargeted' nature of MS imaging allows the detection of marker compounds for the physiological status, as demonstrated for plant-pathogen interactions. Our images show excellent correlation with optical/histological examination. In contrast to previous MS imaging studies of plants, we present a complete workflow that covers multiple species, such as oilseed rape, wheat seed and rice. In addition, different major plant organs and a wide variety of compound classes were analyzed. Thus, our method could be used to develop a plant metabolite atlas as a reference to investigate systemic and local effects of pathogen infection or environmental stress. PMID:26462298

  2. Aboveground Tree Growth Varies with Belowground Carbon Allocation in a Tropical Rainforest Environment

    PubMed Central

    Raich, James W.; Clark, Deborah A.; Schwendenmann, Luitgard; Wood, Tana E.

    2014-01-01

    Young secondary forests and plantations in the moist tropics often have rapid rates of biomass accumulation and thus sequester large amounts of carbon. Here, we compare results from mature forest and nearby 15–20 year old tree plantations in lowland Costa Rica to evaluate differences in allocation of carbon to aboveground production and root systems. We found that the tree plantations, which had fully developed, closed canopies, allocated more carbon belowground - to their root systems - than did mature forest. This increase in belowground carbon allocation correlated significantly with aboveground tree growth but not with canopy production (i.e., leaf fall or fine litter production). In contrast, there were no correlations between canopy production and either tree growth or belowground carbon allocation. Enhanced allocation of carbon to root systems can enhance plant nutrient uptake, providing nutrients beyond those required for the production of short-lived tissues such as leaves and fine roots, and thus enabling biomass accumulation. Our analyses support this deduction at our site, showing that enhanced allocation of carbon to root systems can be an important mechanism promoting biomass accumulation during forest growth in the moist tropics. Identifying factors that control when, where and for how long this occurs would help us to improve models of forest growth and nutrient cycling, and to ascertain the role that young forests play in mitigating increased atmospheric carbon dioxide. PMID:24945351

  3. In situ hybridization for the detection of rust fungi in paraffin embedded plant tissue sections

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rust fungi infect a wide range of plant species making them of particular interest to plant pathologists. In order to study the interactions between these important pathogenic fungi and their host plants it is useful to be able to differentiate fungal tissue from plant tissue. This can be accomplish...

  4. NADPH Oxidase-Dependent Superoxide Production in Plant Reproductive Tissues.

    PubMed

    Jiménez-Quesada, María J; Traverso, José Á; Alché, Juan de Dios

    2016-01-01

    In the life cycle of a flowering plant, the male gametophyte (pollen grain) produced in the anther reaches the stigmatic surface and initiates the pollen-pistil interaction, an important step in plant reproduction, which ultimately leads to the delivery of two sperm cells to the female gametophyte (embryo sac) inside the ovule. The pollen tube undergoes a strictly apical expansion characterized by a high growth rate, whose targeting should be tightly regulated. A continuous exchange of signals therefore takes place between the haploid pollen and diploid tissue of the pistil until fertilization. In compatible interactions, theses processes result in double fertilization to form a zygote (2n) and the triploid endosperm. Among the large number of signaling mechanisms involved, the redox network appears to be particularly important. Respiratory burst oxidase homologs (Rbohs) are superoxide-producing enzymes involved in a broad range of processes in plant physiology. In this study, we review the latest findings on understanding Rboh activity in sexual plant reproduction, with a particular focus on the male gametophyte from the anther development stages to the crowning point of fertilization. Rboh isoforms have been identified in both the male and female gametophyte and have proven to be tightly regulated. Their role at crucial points such as proper growth of pollen tube, self-incompatibility response and eventual fertilization is discussed. PMID:27066025

  5. NADPH Oxidase-Dependent Superoxide Production in Plant Reproductive Tissues

    PubMed Central

    Jiménez-Quesada, María J.; Traverso, José Á.; Alché, Juan de Dios

    2016-01-01

    In the life cycle of a flowering plant, the male gametophyte (pollen grain) produced in the anther reaches the stigmatic surface and initiates the pollen–pistil interaction, an important step in plant reproduction, which ultimately leads to the delivery of two sperm cells to the female gametophyte (embryo sac) inside the ovule. The pollen tube undergoes a strictly apical expansion characterized by a high growth rate, whose targeting should be tightly regulated. A continuous exchange of signals therefore takes place between the haploid pollen and diploid tissue of the pistil until fertilization. In compatible interactions, theses processes result in double fertilization to form a zygote (2n) and the triploid endosperm. Among the large number of signaling mechanisms involved, the redox network appears to be particularly important. Respiratory burst oxidase homologs (Rbohs) are superoxide-producing enzymes involved in a broad range of processes in plant physiology. In this study, we review the latest findings on understanding Rboh activity in sexual plant reproduction, with a particular focus on the male gametophyte from the anther development stages to the crowning point of fertilization. Rboh isoforms have been identified in both the male and female gametophyte and have proven to be tightly regulated. Their role at crucial points such as proper growth of pollen tube, self-incompatibility response and eventual fertilization is discussed. PMID:27066025

  6. Aboveground insect infestation attenuates belowground Agrobacterium-mediated genetic transformation.

    PubMed

    Song, Geun Cheol; Lee, Soohyun; Hong, Jaehwa; Choi, Hye Kyung; Hong, Gun Hyong; Bae, Dong-Won; Mysore, Kirankumar S; Park, Yong-Soon; Ryu, Choong-Min

    2015-07-01

    Agrobacterium tumefaciens causes crown gall disease. Although Agrobacterium can be popularly used for genetic engineering, the influence of aboveground insect infestation on Agrobacterium induced gall formation has not been investigated. Nicotiana benthamiana leaves were exposed to a sucking insect (whitefly) infestation and benzothiadiazole (BTH) for 7 d, and these exposed plants were inoculated with a tumorigenic Agrobacterium strain. We evaluated, both in planta and in vitro, how whitefly infestation affects crown gall disease. Whitefly-infested plants exhibited at least a two-fold reduction in gall formation on both stem and crown root. Silencing of isochorismate synthase 1 (ICS1), required for salicylic acid (SA) synthesis, compromised gall formation indicating an involvement of SA in whitefly-derived plant defence against Agrobacterium. Endogenous SA content was augmented in whitefly-infested plants upon Agrobacterium inoculation. In addition, SA concentration was three times higher in root exudates from whitefly-infested plants. As a consequence, Agrobacterium-mediated transformation of roots of whitefly-infested plants was clearly inhibited when compared to control plants. These results suggest that aboveground whitefly infestation elicits systemic defence responses throughout the plant. Our findings provide new insights into insect-mediated leaf-root intra-communication and a framework to understand interactions between three organisms: whitefly, N. benthamiana and Agrobacterium. PMID:25676198

  7. Response of plant nutrient stoichiometry to fertilization varied with plant tissues in a tropical forest

    PubMed Central

    Mo, Qifeng; Zou, Bi; Li, Yingwen; Chen, Yao; Zhang, Weixin; Mao, Rong; Ding, Yongzhen; Wang, Jun; Lu, Xiankai; Li, Xiaobo; Tang, Jianwu; Li, Zhian; Wang, Faming

    2015-01-01

    Plant N:P ratios are widely used as indices of nutrient limitation in terrestrial ecosystems, but the response of these metrics in different plant tissues to altered N and P availability and their interactions remains largely unclear. We evaluated changes in N and P concentrations, N:P ratios of new leaves (<1 yr), older leaves (>1 yr), stems and mixed fine roots of seven species after 3-years of an N and P addition experiment in a tropical forest. Nitrogen addition only increased fine root N concentrations. P addition increased P concentrations among all tissues. The N × P interaction reduced leaf and stem P concentrations, suggesting a negative effect of N addition on P concentrations under P addition. The reliability of using nutrient ratios as indices of soil nutrient availability varied with tissues: the stoichiometric metrics of stems and older leaves were more responsive indicators of changed soil nutrient availability than those of new leaves and fine roots. However, leaf N:P ratios can be a useful indicator of inter-specific variation in plant response to nutrients availability. This study suggests that older leaf is a better choice than other tissues in the assessment of soil nutrient status and predicting plant response to altered nutrients using nutrients ratios. PMID:26416169

  8. Response of plant nutrient stoichiometry to fertilization varied with plant tissues in a tropical forest.

    PubMed

    Mo, Qifeng; Zou, Bi; Li, Yingwen; Chen, Yao; Zhang, Weixin; Mao, Rong; Ding, Yongzhen; Wang, Jun; Lu, Xiankai; Li, Xiaobo; Tang, Jianwu; Li, Zhian; Wang, Faming

    2015-01-01

    Plant N:P ratios are widely used as indices of nutrient limitation in terrestrial ecosystems, but the response of these metrics in different plant tissues to altered N and P availability and their interactions remains largely unclear. We evaluated changes in N and P concentrations, N:P ratios of new leaves (<1 yr), older leaves (>1 yr), stems and mixed fine roots of seven species after 3-years of an N and P addition experiment in a tropical forest. Nitrogen addition only increased fine root N concentrations. P addition increased P concentrations among all tissues. The N × P interaction reduced leaf and stem P concentrations, suggesting a negative effect of N addition on P concentrations under P addition. The reliability of using nutrient ratios as indices of soil nutrient availability varied with tissues: the stoichiometric metrics of stems and older leaves were more responsive indicators of changed soil nutrient availability than those of new leaves and fine roots. However, leaf N:P ratios can be a useful indicator of inter-specific variation in plant response to nutrients availability. This study suggests that older leaf is a better choice than other tissues in the assessment of soil nutrient status and predicting plant response to altered nutrients using nutrients ratios. PMID:26416169

  9. Temperature dependence of 1H NMR relaxation time, T2, for intact and neoplastic plant tissues

    NASA Astrophysics Data System (ADS)

    Lewa, Czesław J.; Lewa, Maria

    Temperature dependences of the spin-spin proton relaxation time, T2, have been shown for normal and tumorous tissues collected from kalus culture Nicotiana tabacum and from the plant Kalanchoe daigremontiana. For neoplastic plant tissues, time T2 was increased compared to that for intact plants, a finding similar to that for animal and human tissues. The temperature dependences obtained were compared to analogous relations observed with animal tissues.

  10. Cocowood Fibrovascular Tissue System—Another Wonder of Plant Evolution

    PubMed Central

    González, Oswaldo M.; Nguyen, Khoi A.

    2016-01-01

    The coconut palm (Cocos nucifera L.) stem tissue (referred to as cocowood in this study) is a complex fibrovascular system that is made up of fibrovascular bundles embedded into a parenchymatous ground tissue. The complex configuration of fibrovascular bundles along with the non-uniform distribution of the material properties likely allow senile coconut stems to optimize their biomechanical performance per unit mass (i.e., mechanical efficiency) and grow into tall, slender, and very flexible plants with minimum resources of biomass and water. For the first time, to the best of the authors' knowledge, this paper examines, from the integral (i.e., stem structure) and macroscopic (i.e., tissue structure) levels of hierarchy, the characteristic triple helix formation depicted by the fibrovascular bundles within the monocotyledon cocowood. The natural course of the tangential orientation of the axial fibrovascular bundles is mapped for the whole cocowood structure by quantifying 264 cocowood discs, corresponding to 41 senile coconut palms estimated to be >70 years old. The observed variations were modeled in this paper by simple equations that partially enabled characterization of the cocowood fibrovascular tissue system. Furthermore, 11 finite element analyses (FEA) were performed over a three dimensional (3D) finite element (FE) model resembling a characteristic coconut palm stem of 25 m in height to analyze the biomaterial reactions produced by the progressive deviation of the tangential fibrovascular bundles on the cocowood mechanical response (i.e., on the material compressive strength and the bending stiffness). The analyses in this study were carried out for the critical wind speed of 23 m/s (i.e., Gale tornado according to the Fujita tornado scale). For each analysis, the characteristic average maxima degree of orientation of the cocowood fibrovascular bundles was varied from 0° to 51°. The acquired results provided a deep understanding of the cocowood optimum

  11. Cocowood Fibrovascular Tissue System-Another Wonder of Plant Evolution.

    PubMed

    González, Oswaldo M; Nguyen, Khoi A

    2016-01-01

    The coconut palm (Cocos nucifera L.) stem tissue (referred to as cocowood in this study) is a complex fibrovascular system that is made up of fibrovascular bundles embedded into a parenchymatous ground tissue. The complex configuration of fibrovascular bundles along with the non-uniform distribution of the material properties likely allow senile coconut stems to optimize their biomechanical performance per unit mass (i.e., mechanical efficiency) and grow into tall, slender, and very flexible plants with minimum resources of biomass and water. For the first time, to the best of the authors' knowledge, this paper examines, from the integral (i.e., stem structure) and macroscopic (i.e., tissue structure) levels of hierarchy, the characteristic triple helix formation depicted by the fibrovascular bundles within the monocotyledon cocowood. The natural course of the tangential orientation of the axial fibrovascular bundles is mapped for the whole cocowood structure by quantifying 264 cocowood discs, corresponding to 41 senile coconut palms estimated to be >70 years old. The observed variations were modeled in this paper by simple equations that partially enabled characterization of the cocowood fibrovascular tissue system. Furthermore, 11 finite element analyses (FEA) were performed over a three dimensional (3D) finite element (FE) model resembling a characteristic coconut palm stem of 25 m in height to analyze the biomaterial reactions produced by the progressive deviation of the tangential fibrovascular bundles on the cocowood mechanical response (i.e., on the material compressive strength and the bending stiffness). The analyses in this study were carried out for the critical wind speed of 23 m/s (i.e., Gale tornado according to the Fujita tornado scale). For each analysis, the characteristic average maxima degree of orientation of the cocowood fibrovascular bundles was varied from 0° to 51°. The acquired results provided a deep understanding of the cocowood optimum

  12. Extraction of DNA from plant and fungus tissues in situ

    PubMed Central

    2012-01-01

    Background When samples are collected in the field and transported to the lab, degradation of the nucleic acids contained in the samples is frequently observed. Immediate extraction and precipitation of the nucleic acids reduces degradation to a minimum, thus preserving accurate sequence information. An extraction method to obtain high quality DNA in field studies is described. Findings DNA extracted immediately after sampling was compared to DNA extracted after allowing the sampled tissues to air dry at 21°C for 48 or 72 hours. While DNA extracted from fresh tissues exhibited little degradation, DNA extracted from all tissues exposed to 21°C air for 48 or 72 hours exhibited varying degrees of degradation. Yield was higher for extractions from fresh tissues in most cases. Four microcentrifuges were compared for DNA yield: one standard electric laboratory microcentrifuge (max rcf = 16,000×g), two battery-operated microcentrifuges (max rcf = 5,000 and 3,000 ×g), and one manually-operated microcentrifuge (max rcf = 120×g). Yields for all centrifuges were similar. DNA extracted under simulated field conditions was similar in yield and quality to DNA extracted in the laboratory using the same equipment. Conclusions This CTAB (cetyltrimethylammonium bromide) DNA extraction method employs battery-operated and manually-operated equipment to isolate high quality DNA in the field. The method was tested on plant and fungus tissues, and may be adapted for other types of organisms. The method produced high quality DNA in laboratory tests and under simulated field conditions. The field extraction method should prove useful for working in remote sites, where ice, dry ice, and liquid nitrogen are unavailable; where degradation is likely to occur due to the long distances between the sample site and the laboratory; and in instances where other DNA preservation and transportation methods have been unsuccessful. It may be possible to adapt this method for genomic

  13. Aboveground Whitefly Infestation Modulates Transcriptional Levels of Anthocyanin Biosynthesis and Jasmonic Acid Signaling-Related Genes and Augments the Cope with Drought Stress of Maize

    PubMed Central

    Park, Yong-Soon; Bae, Dong-Won; Ryu, Choong-Min

    2015-01-01

    Up to now, the potential underlying molecular mechanisms by which maize (Zea mays L.) plants elicit defense responses by infestation with a phloem feeding insect whitefly [Bemisia tabaci (Genn.)] have been barely elucidated against (a)biotic stresses. To fill this gap of current knowledge maize plants were infested with whitefly and these plants were subsequently assessed the levels of water loss. To understand the mode of action, plant hormone contents and the stress-related mRNA expression were evaluated. Whitefly-infested maize plants did not display any significant phenotypic differences in above-ground tissues (infested site) compared with controls. By contrast, root (systemic tissue) biomass was increased by 2-fold by whitefly infestation. The levels of endogenous indole-3-acetic acid (IAA), jasmonic acid (JA), and hydrogen peroxide (H2O2) were significantly higher in whitefly-infested plants. The biosynthetic or signaling-related genes for JA and anthocyanins were highly up-regulated. Additionally, we found that healthier plants were obtained in whitefly-infested plants under drought conditions. The weight of whitefly-infested plants was approximately 20% higher than that of control plants at 14 d of drought treatment. The drought tolerance-related genes, ZmbZIP72, ZmSNAC1, and ZmABA1, were highly expressed in the whitefly-infected plants. Collectively, our results suggest that IAA/JA-derived maize physiological changes and correlation of H2O2 production and water loss are modulated by above-ground whitefly infestation in maize plants. PMID:26630288

  14. Aboveground Whitefly Infestation Modulates Transcriptional Levels of Anthocyanin Biosynthesis and Jasmonic Acid Signaling-Related Genes and Augments the Cope with Drought Stress of Maize.

    PubMed

    Park, Yong-Soon; Bae, Dong-Won; Ryu, Choong-Min

    2015-01-01

    Up to now, the potential underlying molecular mechanisms by which maize (Zea mays L.) plants elicit defense responses by infestation with a phloem feeding insect whitefly [Bemisia tabaci (Genn.)] have been barely elucidated against (a)biotic stresses. To fill this gap of current knowledge maize plants were infested with whitefly and these plants were subsequently assessed the levels of water loss. To understand the mode of action, plant hormone contents and the stress-related mRNA expression were evaluated. Whitefly-infested maize plants did not display any significant phenotypic differences in above-ground tissues (infested site) compared with controls. By contrast, root (systemic tissue) biomass was increased by 2-fold by whitefly infestation. The levels of endogenous indole-3-acetic acid (IAA), jasmonic acid (JA), and hydrogen peroxide (H2O2) were significantly higher in whitefly-infested plants. The biosynthetic or signaling-related genes for JA and anthocyanins were highly up-regulated. Additionally, we found that healthier plants were obtained in whitefly-infested plants under drought conditions. The weight of whitefly-infested plants was approximately 20% higher than that of control plants at 14 d of drought treatment. The drought tolerance-related genes, ZmbZIP72, ZmSNAC1, and ZmABA1, were highly expressed in the whitefly-infected plants. Collectively, our results suggest that IAA/JA-derived maize physiological changes and correlation of H2O2 production and water loss are modulated by above-ground whitefly infestation in maize plants. PMID:26630288

  15. The correlations between system treatment efficiencies and aboveground emergent macrophyte nutrient removal for the Hsin-Hai Bridge phase II constructed wetland.

    PubMed

    Ko, Chun-Han; Lee, Tsai-Ming; Chang, Fang-Chih; Liao, Shu-Ping

    2011-05-01

    This study investigated the correlations between the system treatment efficiencies and total nitrogen (TN) and total phosphorus (TP) accumulations of aboveground tissues of the wetland macrophytes of Hsin-Hai Bridge phase II constructed wetland. Among 19 emergent macrophytes studied, the optimal TN contents, 3.82% and 3.52% (w/w) were found for water spinach (Ipomoea aquatica) and Ludwigia x taiwanensis; while the optimal TP contents were found for the above two macrophytes at 0.64% and 0.83% (w/w). The accumulations of total plant TN and TP uptakes increased from 213 to 403 kg and 41 to 75 kg from March 2007 to the peak at September 2007, respectively. The TN ratios between plant tissue accumulations and the removals from the influents were 1.57%, 2.76%, 1.51% and 3.2% from March 2007 to March 2008. In the same period, the TP ratios between plant tissue accumulations and the removals from influents were 1.71%, 8.0%, 0.58% and 10.1%. The roles of the uptakes by aboveground portions of emergent macrophytes in system nutrient removals from the influents were more significant during growth seasons. PMID:21106369

  16. Root growth dynamics linked to aboveground growth in walnuts (Juglans regia L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background and Aims: Examination of belowground plant responses to canopy and soil moisture manipulation is scant compared to that aboveground but needed to understand whole plant responses to environmental factors. Plasticity in the seasonal timing and vertical distribution of root growth in respon...

  17. How-To-Do-It: Using Cauliflower to Demonstrate Plant Tissue Culture.

    ERIC Educational Resources Information Center

    Haldeman, Janice H.; Ellis, Jane P.

    1988-01-01

    Presents techniques used for disinfestation of plant material, preparation of equipment and media, and laboratory procedures for tissue culture using cauliflower. Details methods for preparing solutions and plant propagation by cloning. (CW)

  18. [Spatial distribution of aboveground biomass of shrubs in Tianlaochi catchment of the Qilian Mountains].

    PubMed

    Liang, Bei; Di, Li; Zhao, Chuan-Yan; Peng, Shou-Zhang; Peng, Huan-Hua; Wang, Chao

    2014-02-01

    This study estimated the spatial distribution of the aboveground biomass of shrubs in the Tianlaochi catchment of Qilian Mountains based on the field survey and remote sensing data. A relationship model of the aboveground biomass and its feasibly measured factors (i. e. , canopy perimeter and plant height) was built. The land use was classified by object-oriented technique with the high resolution image (GeoEye-1) of the study area, and the distribution of shrub coverage was extracted. Then the total aboveground biomass of shrubs in the study area was estimated by the relationship model with the distribution of shrub coverage. The results showed that the aboveground biomass of shrubs in the study area was 1.8 x 10(3) t and the aboveground biomass per unit area was 1598.45 kg x m(-2). The distribution of shrubs mainly was at altitudes of 3000-3700 m, and the aboveground biomass of shrubs on the sunny slope (1.15 x 10(3) t) was higher than that on the shady slope (0.65 x 10(3) t). PMID:24830234

  19. Techniques for Short and Long-Term Preservation of Plant Tissues and Organs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Preservation of plant tissues can be accomplished using a range of technologies. Whole plants or plant parts from temperate regions can usually be stored under cool to cold conditions for several months to a year. For example, whole strawberry plants can be held at 4°C for up to 6 months. In vitro...

  20. Belowground ABA boosts aboveground production of DIMBOA and primes induction of chlorogenic acid in maize.

    PubMed

    Erb, Matthias; Gordon-Weeks, Ruth; Flors, Victor; Camañes, Gemma; Turlings, Ted C J; Ton, Jurriaan

    2009-07-01

    Plants are important mediators between above- and belowground herbivores. Consequently, interactions between root and shoot defenses can have far-reaching impacts on entire food webs. We recently reported that infestation of maize roots by larvae of the beetle Diabrotica virgifera virgifera induced shoot resistance against herbivores and pathogens. Root herbivory also enhanced aboveground DIMBOA and primed for enhanced induction of chlorogenic acid, two secondary metabolites that have been associated with plant stress resistance. Interestingly, the plant hormone abscisic acid (ABA) emerged as a putative long-distance signal in the regulation of these systemic defenses. In this addendum, we have investigated the role of root-derived ABA in aboveground regulation of DIMBOA and the phenolic compounds chlorogenic acid, caffeic and ferulic acid. Furthermore, we discuss the relevance of ABA in relation to defense against the leaf herbivore Spodoptera littoralis. Soil-drench treatment with ABA mimicked root herbivore-induced accumulation of DIMBOA in the leaves. Similarly, ABA mimicked aboveground priming of chlorogenic acid production, causing augmented induction of this compound after subsequent shoot attack by S. littoralis caterpillars. These findings confirm our notion that ABA acts as an important signal in the regulation of aboveground defenses during belowground herbivory. However, based on our previous finding that ABA alone is not sufficient to trigger aboveground resistance against S. littoralis caterpillars, our results also suggest that the ABA-inducible effects on DIMBOA and chlorogenic acid are not solely responsible for root herbivore-induced resistance against S. littoralis. PMID:19820311

  1. Conjugation in Agrobacterium tumefaciens in the absence of plant tissue.

    PubMed Central

    Levin, R A; Farrand, S K; Gordon, M P; Nester, E W

    1976-01-01

    A general, reliable conjugation system for Agrobacterium tumefaciens in the absence of plant tissue is described in which A. tumefaciens can serve either as the donor or recipient of plasmid deoxyribonucleic acid with reasonable efficiency. Plasmid RP4 was transferred from Escherichia coli to A. tumefaciens and from strain of A. tumefaciens. Both RP4 and the A. tumefaciens virulence-associated plasmids were detected by alkaline sucrose gradients in A. tumefaciens strains A6 and C58 after mating with E. coli J53(RP4). The pathogenicity (tumor foramtion) of strains A6 and C58 and the sensitivity of strain C58 to bacteriocin 84 were unaffected by the acquistion of RP4 by the Agrobacterium strains. Plasmid R1drd-19 was not transferred to A. tumefaciens. Transformation experiments with plasmid deoxyribonucleic acid were unsuccessful, even though, in the case of RP4, conjugation studies showed taht the deoxyribonucleic acid was compatible with that of the recipient strains. PMID:783141

  2. Plant intentionality and the phenomenological framework of plant intelligence

    PubMed Central

    Marder, Michael

    2012-01-01

    This article aims to bridge phenomenology and the study of plant intelligence with the view to enriching both disciplines. Besides considering the world from the perspective of sessile organisms, it would be necessary, in keeping with the phenomenological framework, to rethink (1) the meaning of being-sessile and being-in-a-place; (2) the concepts of sentience and attention; (3) how aboveground and underground environments appear to plants; (4) the significance of modular development for our understanding of intelligence; and (5) the concept of communication within and between plants and plant tissues. What emerges from these discussions is the image of a mind embodied in plant life. PMID:22951403

  3. Aboveground storage tanks: Understanding the rules

    SciTech Connect

    Kitchen, T.; McCallion, J.

    1995-10-01

    Facility owners and operators using aboveground tanks for storing or processing hazardous wastes or oils must follow Environmental Protection Agency (EPA) or Occupational Safety and Health Administration (OSHA) regulations, or they risk heavy fines and penalties. Every facility storing more than 1320 gallons of hazardous waste or oil aboveground or more than 660 gallons in a single tank are required to have a spill prevention control and countermeasures plan. Given in the article is a table of aboveground tank standards under various agencies or acts. The subject and location of these regulations from the EPA, OSHA, Resource Conservation and Recovery Act (RCRA), Underwriter`s Laboratory (UL), the American Petroleum Institute (API), and the American Society of Mechanical Engineers (ASME) cover various aspects of tank construction and safety. Understanding and complying with the codes and regulations can be arduous, but the rewards in safety and environmental stewardship and the potential savings in fines make the effort worthwhile.

  4. Stachyose synthesis in source leaf tissues of the CAM plant Xerosicyos danguyi H. Humb

    SciTech Connect

    Madore, M.A.; Mitchell, D.E.; Boyd, C.M. )

    1988-07-01

    Leaf tissues from Xerosicyos danguyi H. Humb., a succulent member of the Cucurbitaceae, were found to possess both galactinol synthase activity and the capacity for photosynthetic production of stachyose, the phloem transport oligosaccahride common to other nonsucculent cucurbits, the amounts of stachyose isolated from leaf tissues, and the extractable activity of galactinol synthase, were somewhat higher in leaf tissues obtained from plants operating in the Crassulacean acid metabolism (CAM) mode (well watered plants) compared to leaf tissues from plants operating in the CAM-idling mode (water-stressed plants). In contrast, in leaf discs, the photosynthetic incorporation of label into stachyose following pulse labeling with {sup 14}CO{sub 2} was similar for stressed and for nonstressed tissues. Stachyose could be extracted from, and was synthesized photosynthetically by, leaf discs which contained no vascular tissues, indicating that synthesis of stachyose can occur in photosynthetic mesophyll cells of Xerosicyos.

  5. Translocation of radiocesium from stems and leaves of plants and the effect on radiocesium concentrations in newly emerged plant tissues.

    PubMed

    Tagami, Keiko; Uchida, Shigeo; Ishii, Nobuyoshi; Kagiya, Shigeo

    2012-09-01

    An accident occurred at the Fukushima Dai-ichi Nuclear Power Plant in March 2011 at which time large amounts of radionuclides were released into the atmosphere and the sea. In early May 2011, it was found that newly emerged tea (Camellia sinensis) leaves contained radiocesium, both (134)Cs and (137)Cs in some areas more than 300 km away from the Fukushima plant. To understand the mechanisms of radiocesium transfer to newly emerged tissues (shoots, leaves and fruits) of other plants in the future, radiocesium concentrations in newly emerged leaves of 14 plant species collected from the sampling areas in and near National Institute of Radiological Sciences in Chiba, Japan. The studied plant types were: (1) herbaceous plants, (2) woody plants with no old leaves at the time of the March accident, and (3) woody plants with old leaves out before the accident. About 40-50 d after the start of the accident, newly emerged leaves from woody plant with old leaves tended to show higher values than other woody or herbaceous plants. Concentrations of radiocesium in newly emerged tissues of trees decreased with time, but they did not decrease to the level of herbaceous plants. The type of the plant and presence of old leaves at the time of the heavy deposition period affected the radiocesium concentrations in newly emerged tissues. PMID:22027214

  6. Using Peat Pellets in Liquid Media to Root Sunflower Tissue Culture Plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Traditional plant breeding is often limited by the genetic diversity within a species. The use of biotechnology allows introducing into a plant, specific traits that come from the same or another plant species. In this paper, we focus on tissue culture of sunflower (Helianthus annus L., Asteraceae...

  7. Stimulation of the Salicylic Acid Pathway Aboveground Recruits Entomopathogenic Nematodes Belowground.

    PubMed

    Filgueiras, Camila Cramer; Willett, Denis S; Junior, Alcides Moino; Pareja, Martin; Borai, Fahiem El; Dickson, Donald W; Stelinski, Lukasz L; Duncan, Larry W

    2016-01-01

    Plant defense pathways play a critical role in mediating tritrophic interactions between plants, herbivores, and natural enemies. While the impact of plant defense pathway stimulation on natural enemies has been extensively explored aboveground, belowground ramifications of plant defense pathway stimulation are equally important in regulating subterranean pests and still require more attention. Here we investigate the effect of aboveground stimulation of the salicylic acid pathway through foliar application of the elicitor methyl salicylate on belowground recruitment of the entomopathogenic nematode, Steinernema diaprepesi. Also, we implicate a specific root-derived volatile that attracts S. diaprepesi belowground following aboveground plant stimulation by an elicitor. In four-choice olfactometer assays, citrus plants treated with foliar applications of methyl salicylate recruited S. diaprepesi in the absence of weevil feeding as compared with negative controls. Additionally, analysis of root volatile profiles of citrus plants receiving foliar application of methyl salicylate revealed production of d-limonene, which was absent in negative controls. The entomopathogenic nematode S. diaprepesi was recruited to d-limonene in two-choice olfactometer trials. These results reinforce the critical role of plant defense pathways in mediating tritrophic interactions, suggest a broad role for plant defense pathway signaling belowground, and hint at sophisticated plant responses to pest complexes. PMID:27136916

  8. Stimulation of the Salicylic Acid Pathway Aboveground Recruits Entomopathogenic Nematodes Belowground

    PubMed Central

    Filgueiras, Camila Cramer; Willett, Denis S.; Junior, Alcides Moino; Pareja, Martin; Borai, Fahiem El; Dickson, Donald W.; Stelinski, Lukasz L.; Duncan, Larry W.

    2016-01-01

    Plant defense pathways play a critical role in mediating tritrophic interactions between plants, herbivores, and natural enemies. While the impact of plant defense pathway stimulation on natural enemies has been extensively explored aboveground, belowground ramifications of plant defense pathway stimulation are equally important in regulating subterranean pests and still require more attention. Here we investigate the effect of aboveground stimulation of the salicylic acid pathway through foliar application of the elicitor methyl salicylate on belowground recruitment of the entomopathogenic nematode, Steinernema diaprepesi. Also, we implicate a specific root-derived volatile that attracts S. diaprepesi belowground following aboveground plant stimulation by an elicitor. In four-choice olfactometer assays, citrus plants treated with foliar applications of methyl salicylate recruited S. diaprepesi in the absence of weevil feeding as compared with negative controls. Additionally, analysis of root volatile profiles of citrus plants receiving foliar application of methyl salicylate revealed production of d-limonene, which was absent in negative controls. The entomopathogenic nematode S. diaprepesi was recruited to d-limonene in two-choice olfactometer trials. These results reinforce the critical role of plant defense pathways in mediating tritrophic interactions, suggest a broad role for plant defense pathway signaling belowground, and hint at sophisticated plant responses to pest complexes. PMID:27136916

  9. Rapid and simple isolation of vascular, epidermal and mesophyll cells from plant leaf tissue.

    PubMed

    Endo, Motomu; Shimizu, Hanako; Araki, Takashi

    2016-08-01

    To understand physiological phenomena at the tissue level, elucidation of tissue-specific molecular functions in vivo is required. As an example of the current state of affairs, many genes in plants have been reported to have discordant levels of expression between bulk tissues and the specific tissues in which the respective gene product is principally functional. The principal challenge in deciphering such tissue-specific functions lies in separating tissues with high spatiotemporal resolution to evaluate accurate gene expression profiles. Here, we provide a simple and rapid tissue isolation protocol to isolate all three major leaf tissues (mesophyll, vasculature and epidermis) from Arabidopsis within 30 min with high purity. On the basis of the different cell-to-cell connectivities of tissues, the mesophyll isolation is achieved by making protoplasts, and the vasculature and epidermis isolation is achieved through sonication and enzymatic digestion of leaves. We have successfully tested the protocol on several other plant species, including crop plants such as soybean, tomato and wheat. Furthermore, isolated tissues can be used not only for tissue-specific transcriptome assays but also potentially for tissue-specific proteome and methylome assays. PMID:27388555

  10. Below-ground herbivory limits induction of extrafloral nectar by above-ground herbivores

    PubMed Central

    Huang, Wei; Siemann, Evan; Carrillo, Juli; Ding, Jianqing

    2015-01-01

    Background and Aims Many plants produce extrafloral nectar (EFN), and increase production following above-ground herbivory, presumably to attract natural enemies of the herbivores. Below-ground herbivores, alone or in combination with those above ground, may also alter EFN production depending on the specificity of this defence response and the interactions among herbivores mediated through plant defences. To date, however, a lack of manipulative experiments investigating EFN production induced by above- and below-ground herbivory has limited our understanding of how below-ground herbivory mediates indirect plant defences to affect above-ground herbivores and their natural enemies. Methods In a greenhouse experiment, seedlings of tallow tree (Triadica sebifera) were subjected to herbivory by a specialist flea beetle (Bikasha collaris) that naturally co-occurs as foliage-feeding adults and root-feeding larvae. Seedlings were subjected to above-ground adults and/or below-ground larvae herbivory, and EFN production was monitored. Key Results Above- and/or below-ground herbivory significantly increased the percentage of leaves with active nectaries, the volume of EFN and the mass of soluble solids within the nectar. Simultaneous above- and below-ground herbivory induced a higher volume of EFN and mass of soluble solids than below-ground herbivory alone, but highest EFN production was induced by above-ground herbivory when below-ground herbivores were absent. Conclusions The induction of EFN production by below-ground damage suggests that systemic induction underlies some of the EFN response. The strong induction by above-ground herbivory in the absence of below-ground herbivory points to specific induction based on above- and below-ground signals that may be adaptive for this above-ground indirect defence. PMID:25681822

  11. Therapeutically important proteins from in vitro plant tissue culture systems.

    PubMed

    Doran, Pauline M

    2013-01-01

    Plant cells cultured in liquid medium in bioreactors are now being used commercially to produce biopharmaceutical proteins. The emergence of in vitro plant cell culture as a production vehicle reflects the importance of key biosafety and biocontainment concerns affecting the competitiveness of alternative systems such as mammalian cell culture and agriculture. Food plant species are particularly attractive as hosts for in vitro protein production: the risk of transgene escape and food chain contamination is eliminated using containment facilities, while regulatory approval for oral delivery of drugs may be easier than if non-edible species were used. As in whole plants, proteolysis in cultured plant cells can lead to significant degradation of foreign proteins after synthesis; however, substantial progress has been made to counter the destructive effects of proteases in plant systems. Although protein secretion into the culture medium is advantageous for product recovery and purification, measures are often required to minimise extracellular protease activity and product losses due to irreversible surface adsorption. Disposable plastic bioreactors, which are being used increasingly in mammalian cell bioprocessing, are also being adopted for plant cell culture to allow rapid scale-up and generation of saleable product. This review examines a range of technical and regulatory issues affecting the choice of industrial production platform for foreign proteins, and assesses progress in the development of in vitro plant systems for biopharmaceutical production. PMID:23210789

  12. Bacterial Communities Associated with Different Anthurium andraeanum L. Plant Tissues

    PubMed Central

    Sarria-Guzmán, Yohanna; Chávez-Romero, Yosef; Gómez-Acata, Selene; Montes-Molina, Joaquín Adolfo; Morales-Salazar, Eleacin; Dendooven, Luc; Navarro-Noya, Yendi E.

    2016-01-01

    Plant-associated microbes have specific beneficial functions and are considered key drivers for plant health. The bacterial community structure of healthy Anthurium andraeanum L. plants was studied by 16S rRNA gene pyrosequencing associated with different plant parts and the rhizosphere. A limited number of bacterial taxa, i.e., Sinorhizobium, Fimbriimonadales, and Gammaproteobacteria HTCC2089 were enriched in the A. andraeanum rhizosphere. Endophytes were more diverse in the roots than in the shoots, whereas all shoot endophytes were found in the roots. Streptomyces, Flavobacterium succinicans, and Asteroleplasma were only found in the roots, Variovorax paradoxus only in the stem, and Fimbriimonas 97%-OTUs only in the spathe, i.e., considered specialists, while Brevibacillus, Lachnospiraceae, Pseudomonas, and Pseudomonas pseudoalcaligenes were generalist and colonized all plant parts. The anaerobic diazotrophic bacteria Lachnospiraceae, Clostridium sp., and Clostridium bifermentans colonized the shoot system. Phylotypes belonging to Pseudomonas were detected in the rhizosphere and in the substrate (an equiproportional mixture of soil, cow manure, and peat), and dominated the endosphere. Pseudomonas included nine 97%-OTUs with different patterns of distribution and phylogenetic affiliations with different species. P. pseudoalcaligenes and P. putida dominated the shoots, but were also found in the roots and rhizosphere. P. fluorescens was present in all plant parts, while P. resinovorans, P. denitrificans, P. aeruginosa, and P. stutzeri were only detected in the substrate and rhizosphere. The composition of plant-associated bacterial communities is generally considered to be suitable as an indicator of plant health. PMID:27524305

  13. Capturing Plant Metabolome with Direct-Immersion in Vivo Solid Phase Microextraction of Plant Tissues.

    PubMed

    Risticevic, Sanja; Souza-Silva, Erica A; DeEll, Jennifer R; Cochran, Jack; Pawliszyn, Janusz

    2016-01-19

    For the first time, an in vivo sampling mode of direct immersion-solid phase microextraction (DI-SPME) was employed to capture the metabolome of living plant specimens, using apple (Malus × domestica Borkh.) as a model system. Metabolites were extracted from apple tissues and introduced by thermal desorption into a comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry instrument. The feasibility of this sampling approach, based on exploitation of microextraction principles, including negligible depletion of free analyte concentrations, solventless sampling and sample preparation, and on-site compatibility, was determined in global metabolite analysis. Rather than adopting an approach of traditional sample preparation, requiring metabolism quenching and laborious sample preparation, the objective of the study was to capture the metabolome in vivo, evaluate the feasibility of the approach to provide unbiased extraction coverage, and compare analytical precision when different SPME sampling modes are employed. The potential of in vivo DI-SPME in quantitative plant metabolomics was assessed by evaluating changes in metabolic fingerprints in response to fruit maturation. The in vivo SPME sampling approach has been demonstrated as capable of sampling living systems with high reproducibility, considering that nearly 50% of hundreds of evaluated compounds included in the determination of analytical performance met the 15% RSD FDA criterion. Esters were extracted with high repeatability (% RSD for hexyl butanoate and butyl butanoate of 16.5 and 5.9, respectively, from 9 determinations in 3 apples) and found to be upregulated in response to apple fruit maturation. PMID:26666307

  14. Mass Spectrometric Analysis of Cytokinins in Plant Tissues 1

    PubMed Central

    Palni, Lok Man S.; Summons, Roger E.; Letham, David S.

    1983-01-01

    The cytokinin complex of Datura innoxia Mill. crown gall tissue was purified by ion exchange, Sephadex LH-20 chromatography and reversed-phase high performance liquid chromatography. By gas chromatography-mass spectrometry using 2H-labeled compounds, the following cytokinins were identified in the basic fraction eluting from a cation exchange column: zeatin, zeatin riboside, dihydrozeatin, dihydrozeatin riboside, their corresponding O-glucosides, 7- and 9-glucosides of zeatin, 9-glucoside of dihydrozeatin, isopentenyladenine, and isopentenyladenosine. Zeatin riboside 5′-monophosphate was the major cytokinin nucleotide in the tissue. In addition, dihydrozeatin riboside and isopentenyladenosine were identified in the nucleotide fraction following enymic degradation. PMID:16663099

  15. Survival of cultured plant cells grafted into the subcutaneous tissue of rats (preliminary report).

    PubMed

    Lozoya, X; Madrazo, I; Guizar, G; Villarreal, M L; Grijalva, I; Salgado, H; Boijseauneau, E; Ibarra, A; Arias-Castro, C; Rodríguez-Mendiola, M A

    1995-01-01

    To evaluate the survival of plant tissue in an animal environment, cultured calli from a Mexican medicinal plant (Mimosa tenuiflora Poir.) were transplanted under sterile conditions into the subcutaneous tissue of rats. Microscopic studies of grafted areas were carried out at the 30th, 60th and 120th days after transplantation. Histological evidence of plant graft survival was found in specimens of all groups. during the first month of subcutaneous grafting a moderate inflammatory reaction around the callus was observed characterized by the presence of polymorphonuclear cells and some macrophages and the formation of a fibrous capsule. Nevertheless, the plant grafts remained viable and a decrease of the inflammatory reaction around the callus was observed in the specimens during the following months. In the fourth month specimens the formation of blood vessels inside the grafted plant tissue was observed. Once removed from rats, plant tissues showed high viability according to the fluorescein test. These calli were then transferred to the original in vitro medium showing growth capacity during the following weeks. These results demonstrate, for the first time, that cultivated cells of higher plants survive in an animal environment, suggesting the possibility to utilize pharmacologically active plant transplants in animals, a technique proposed here as inter-regni transplants. Further studies are required to explore this new field of research that opens numerous questions about plant-animal cellular interaction. PMID:7711454

  16. Life cycle specialization of filamentous pathogens - colonization and reproduction in plant tissues.

    PubMed

    Haueisen, Janine; Stukenbrock, Eva H

    2016-08-01

    Filamentous plant pathogens explore host tissues to obtain nutrients for growth and reproduction. Diverse strategies for tissue invasion, defense manipulation, and colonization of inter and intra-cellular spaces have evolved. Most research has focused on effector molecules, which are secreted to manipulate plant immunity and facilitate infection. Effector genes are often found to evolve rapidly in response to the antagonistic host-pathogen co-evolution but other traits are also subject to adaptive evolution during specialization to the anatomy, biochemistry and ecology of different plant hosts. Although not directly related to virulence, these traits are important components of specialization but little is known about them. We present and discuss specific life cycle traits that facilitate exploration of plant tissues and underline the importance of increasing our insight into the biology of plant pathogens. PMID:27153045

  17. Deer browsing delays succession by altering aboveground vegetation and belowground seed banks.

    PubMed

    DiTommaso, Antonio; Morris, Scott H; Parker, John D; Cone, Caitlin L; Agrawal, Anurag A

    2014-01-01

    Soil seed bank composition is important to the recovery of natural and semi-natural areas from disturbance and serves as a safeguard against environmental catastrophe. White-tailed deer (Odocoileus virginianus) populations have increased dramatically in eastern North America over the past century and can have strong impacts on aboveground vegetation, but their impacts on seed bank dynamics are less known. To document the long-term effects of deer browsing on plant successional dynamics, we studied the impacts of deer on both aboveground vegetation and seed bank composition in plant communities following agricultural abandonment. In 2005, we established six 15 × 15 m fenced enclosures and paired open plots in recently followed agricultural fields near Ithaca, NY, USA. In late October of each of six years (2005-2010), we collected soil from each plot and conducted seed germination cycles in a greenhouse to document seed bank composition. These data were compared to measurements of aboveground plant cover (2005-2008) and tree density (2005-2012). The impacts of deer browsing on aboveground vegetation were severe and immediate, resulting in significantly more bare soil, reduced plant biomass, reduced recruitment of woody species, and relatively fewer native species. These impacts persisted throughout the experiment. The impacts of browsing were even stronger on seed bank dynamics. Browsing resulted in significantly decreased overall species richness (but higher diversity), reduced seed bank abundance, relatively more short-lived species (annuals and biennials), and fewer native species. Both seed bank richness and the relative abundance of annuals/biennials were mirrored in the aboveground vegetation. Thus, deer browsing has long-term and potentially reinforcing impacts on secondary succession, slowing succession by selectively consuming native perennials and woody species and favoring the persistence of short-lived, introduced species that continually recruit from an

  18. Deer Browsing Delays Succession by Altering Aboveground Vegetation and Belowground Seed Banks

    PubMed Central

    DiTommaso, Antonio; Morris, Scott H.; Parker, John D.; Cone, Caitlin L.; Agrawal, Anurag A.

    2014-01-01

    Soil seed bank composition is important to the recovery of natural and semi-natural areas from disturbance and serves as a safeguard against environmental catastrophe. White-tailed deer (Odocoileus virginianus) populations have increased dramatically in eastern North America over the past century and can have strong impacts on aboveground vegetation, but their impacts on seed bank dynamics are less known. To document the long-term effects of deer browsing on plant successional dynamics, we studied the impacts of deer on both aboveground vegetation and seed bank composition in plant communities following agricultural abandonment. In 2005, we established six 15×15 m fenced enclosures and paired open plots in recently fallowed agricultural fields near Ithaca, NY, USA. In late October of each of six years (2005–2010), we collected soil from each plot and conducted seed germination cycles in a greenhouse to document seed bank composition. These data were compared to measurements of aboveground plant cover (2005–2008) and tree density (2005–2012). The impacts of deer browsing on aboveground vegetation were severe and immediate, resulting in significantly more bare soil, reduced plant biomass, reduced recruitment of woody species, and relatively fewer native species. These impacts persisted throughout the experiment. The impacts of browsing were even stronger on seed bank dynamics. Browsing resulted in significantly decreased overall species richness (but higher diversity), reduced seed bank abundance, relatively more short-lived species (annuals and biennials), and fewer native species. Both seed bank richness and the relative abundance of annuals/biennials were mirrored in the aboveground vegetation. Thus, deer browsing has long-term and potentially reinforcing impacts on secondary succession, slowing succession by selectively consuming native perennials and woody species and favoring the persistence of short-lived, introduced species that continually recruit

  19. Sample Preparation for Mass Spectrometry Imaging of Plant Tissues: A Review

    PubMed Central

    Dong, Yonghui; Li, Bin; Malitsky, Sergey; Rogachev, Ilana; Aharoni, Asaph; Kaftan, Filip; Svatoš, Aleš; Franceschi, Pietro

    2016-01-01

    Mass spectrometry imaging (MSI) is a mass spectrometry based molecular ion imaging technique. It provides the means for ascertaining the spatial distribution of a large variety of analytes directly on tissue sample surfaces without any labeling or staining agents. These advantages make it an attractive molecular histology tool in medical, pharmaceutical, and biological research. Likewise, MSI has started gaining popularity in plant sciences; yet, information regarding sample preparation methods for plant tissues is still limited. Sample preparation is a crucial step that is directly associated with the quality and authenticity of the imaging results, it therefore demands in-depth studies based on the characteristics of plant samples. In this review, a sample preparation pipeline is discussed in detail and illustrated through selected practical examples. In particular, special concerns regarding sample preparation for plant imaging are critically evaluated. Finally, the applications of MSI techniques in plants are reviewed according to different classes of plant metabolites. PMID:26904042

  20. ETHYLMERCURY: FORMATION IN PLANT TISSUES AND RELATION TO METHYLMERCURY FORMATION

    EPA Science Inventory

    Seedlings of the common dwarf garden pea, Pisum sativum, cv. Little Marvel, exposed to elemental mercury vapor formed both methylmercury and ethylmercury in all parts of the plant. Concentrations of both organomercury compounds fluctuated considerably over a 48-hour exposure peri...

  1. Plant Tissue Preparation for the Detection of an Endophytic Fungus In Planta.

    PubMed

    McKinnon, Aimee C

    2016-01-01

    The identification of fungal endophytes often relies on culturing isolates from surface-sterilized plant tissue. However, molecular techniques have enabled the rapid detection and identification of targeted endophyte species, and next-generation sequencing technology provides an opportunity to obtain comprehensive information on endophytic communities, directly from plant tissue. In order to achieve accurate detection from internal tissues, surface microbes and associated deoxyribonucleic acid (DNA) must be eliminated, with particular consideration for the type of plant tissue and the efficacy of the surface sterilization procedure used. The methodology described later was developed specifically for detection of DNA from the entomopathogenic fungal endophyte Beauveria bassiana (Vuillemin) (Ascomycota: Hypocreales) in various tissues of Zea mays (L.). However, the protocol may be easily applied to other fungi and bacterial endophytes. Included is a stringent sodium hypochlorite-based surface sterilization protocol for plant material in preparation for polymerase chain reaction (PCR) to detect target DNA within plant tissue. Included are a treatment for dealing with surface DNA contamination and a novel procedure for assessing the efficacy of surface sterilization using PCR. PMID:27565499

  2. Impact of a pulsed electric field on damage of plant tissues: effects of cell size and tissue electrical conductivity.

    PubMed

    Ben Ammar, J; Lanoisellé, J-L; Lebovka, N I; Van Hecke, E; Vorobiev, E

    2011-01-01

    Efficiency of pulsed electric field (PEF) induced permeabilization at 293 K in selected fruit and vegetable plant tissues (apple, potato, carrot, courgette, orange, and banana) at electric field strength (E) of 400 V·cm(-1), 1000 V·cm(-1) and pulse duration (t(p)) of 1000 μs was studied experimentally. The mean cell radius (〈r〉) was within 30 to 60 μm, and the ratio of electrical conductivities of the intact and damaged tissues (σ(i)/σ(d)) was within 0.07 to 0.79 for the studied tissues. Electroporation theory predicts higher damage for tissue with larger cells; however, the direct correlation between PEF damage efficiency and size of cell was not always observed. To explain this anomaly, a theoretical Monte Carlo model was developed and checked for parameters typical for potato tissue. The model showed a strong dependence of PEF damage efficiency and power consumption (W) on σ(i)/σ(d) ratio. The optimum value of electric field strength (E(opt)) was an increasing function of σ(i)/σ(d), and plant tissues with high σ(i)/σ(d) ratio (σ(i)/σ(d) ≈ 1) required application of a rather strong field (for example, E(opt) ≈ 3000 V·cm(-1) for σ(i)/σ(d) ≈ 0.8). However, the PEF treatment at a lower field (E ≈ 400 V·cm(-1)) allowed regulation of the selectivity of damage of cells in dependence of their size. A good qualitative correspondence between experimental data and simulation results were observed. PMID:21535680

  3. Monovinyl and Divinyl Protochlorophyllide Pools in Etiolated Tissues of Higher Plants 1

    PubMed Central

    Shioi, Yuzo; Takamiya, Ken-ichiro

    1992-01-01

    The composition of chlorophyll-precursor pigments, particularly the contents of monovinyl (MV) and divinyl (DV) protochlorophyllides (Pchlides), in etiolated tissues of higher plants were determined by polyethylene-column HPLC (Y. Shioi, S. I. Beale [1987] Anal Biochem 162: 493-499), which enables the complete separation of these pigments. DV-Pchlide was ubiquitous in etiolated tissue of higher plants. From the analyses of 24 plant species belonging to 17 different families, it was shown that the concentration of DV-Pchlide was strongly dependent on the plant species and the age of the plants. The ratio of DV-Pchlide to MV-Pchlide in high DV-Pchlide plants such as cucumber and leaf mustard decreased sharply with increasing age. Levels of DV-Pchlide in Gramineae plants were considerably lower at all ages compared with those of other plants. Etiolated tissues of higher plants such as barley and corn were, therefore, good sources of MV-Pchlide. Absorption spectra of the purified MV- and DV-Pchlides in ether are presented and compared. PMID:16653119

  4. Improved method for HPLC analysis of polyamines, agmatine and aromatic monoamines in plant tissue

    NASA Technical Reports Server (NTRS)

    Slocum, R. D.; Flores, H. E.; Galston, A. W.; Weinstein, L. H.

    1989-01-01

    The high performance liquid chromatographic (HPLC) method of Flores and Galston (1982 Plant Physiol 69: 701) for the separation and quantitation of benzoylated polyamines in plant tissues has been widely adopted by other workers. However, due to previously unrecognized problems associated with the derivatization of agmatine, this important intermediate in plant polyamine metabolism cannot be quantitated using this method. Also, two polyamines, putrescine and diaminopropane, also are not well resolved using this method. A simple modification of the original HPLC procedure greatly improves the separation and quantitation of these amines, and further allows the simulation analysis of phenethylamine and tyramine, which are major monoamine constituents of tobacco and other plant tissues. We have used this modified HPLC method to characterize amine titers in suspension cultured carrot (Daucas carota L.) cells and tobacco (Nicotiana tabacum L.) leaf tissues.

  5. Cloning higher plants from aseptically cultured tissues and cells

    NASA Technical Reports Server (NTRS)

    Krikorian, A. D.

    1982-01-01

    A review of aseptic culture methods for higher plants is presented, which focuses on the existing problems that limit or prevent the full realization of cloning plants from free cells. It is shown that substantial progress in clonal multiplication has been made with explanted stem tips or lateral buds which can be stimulated to produce numerous precocious axillary branches. These branches can then be separated or subdivided and induced to root in order to yield populations of genetically and phenotypically uniorm plantlets. Similarly, undifferentiated calluses can sometimes be induced to form shoots and/or roots adventitiously. Although the cell culture techniques required to produce somatic embryos are presently rudimentary, steady advances are being made in learning how to stimulate formation of somatic or adventive embryos from totipotent cells grown in suspension cultures. It is concluded that many problems exist in the producing and growing of totipotent or morphogenetically competent cell suspensions, but the potential benefits are great.

  6. Surviving freezing in plant tissues by oomycetous snow molds.

    PubMed

    Murakami, Ryo; Yajima, Yuka; Kida, Ken-ichi; Tokura, Katsuyuki; Tojo, Motoaki; Hoshino, Tamotsu

    2015-04-01

    Oomyceteous snow molds, Pythium species, were reported to be less tolerant to chilling and freezing temperatures than other snow mold taxa. However, Pythium species are often found to be pathogenic on mosses in Polar Regions. We investigated the frost resistance of Pythium species from Temperate (Hokkaido, Japan) and Subantarctic Regions. Free mycelia and hyphal swellings, structures for survival, of Pythium iwayamai and Pythium paddicum lost viability within freeze-thaw 3 cycles; however, mycelia in host plants survived the treatment. It was reported that fungi in permafrost are characterized both by the presence of natural cryoprotectants in these ecotopes and by the ability to utilize their inherent mechanisms of protection. It is conceivable that plant substrates or derivatives thereof are natural cryoprotectants, enabling them to provide advantageous conditions to microorganisms under freezing conditions. Our results are the first to experimentally support this hypothesis. PMID:25661659

  7. Role of proteolytic enzymes in degradation of plant tissues

    SciTech Connect

    Lewosz, J.; Kelman, A.; Sequeira, L.

    1991-01-01

    Strain SR 394 of Erwinia carotovora (Ecc) produced proteases constitutively in all media tested. Growth of Ecc and production of protease were enhanced significantly by the presence of poetic materials and/or plant call walls in the test media. After electrofocusing, one major and one minor protease bands, at PI 4.8 and PI 5.1, respectively, were detected. Only one band of 43 kDa was detected on SDS gels. Only one protease band was detected in SDS gels of infected plant extracts. This protease was purified to homogeneity. It in a highly thermostable metal protease; it degrades gelatin, soluble collagen and hide powderazure, shows weak activity on casein and azocasein, but does not degrade insoluble collagen or elastin.

  8. Polyphosphoinositides are present in plant tissue culture cells

    SciTech Connect

    Boss, W.F.; Massel, M.O.

    1985-11-15

    Polyphosphoinositides have been isolated from wild carrot cells grown in suspension culture. This is the first report of polyphosphoinositides in plant cells. The phospholipids were identified by comigration with known standards on thin-layer plates. After overnight labeling of the cells with myo-(2-/sup 3/H) inositol, the phosphoinositides as percent recovered inositol were 93% phosphatidylinositol., 3.7% lysophosphatidylinositol, 1.7% phosphatidylinositol monophosphate, 0.8% phosphatidylinositol bisphosphate.

  9. Demonstration of the economic feasibility of plant tissue culture for jojoba (Simmondsia chinensis) and Euphorbia spp

    SciTech Connect

    Sluis, C.

    1980-09-01

    The economic feasibility of plant tissue culture was demonstrated as applied to two plants: jojoba (Simmondsia chinensis) and Euphorbia spp. The gopher weed (Euphorbia lathyris) was selected as the species of Euphorbia to research due to the interest in this plant as a potential source of hydrocarbon-like compounds. High yield female selections of jojoba were chosen from native stands and were researched to determine the economic feasibility of mass producing these plants via a tissue culture micropropagation program. The female jojoba selection was successfully mass produced through tissue culture. Modifications in initiation techniques, as well as in multiplication media and rooting parameters, were necessary to apply the tissue culture system, which had been developed for juvenile seedling tissue, to mature jojobas. Since prior attempts at transfer of tissue cultured plantlets were unsuccessful, transfer research was a major part of the project and has resulted in a system for transfer of rooted jojoba plantlets to soil. Euphorbia lathyris was successfully cultured using shoot tip cultures. Media and procedures were established for culture initiation, multiplication of shoots, callus induction and growth, and root initiation. Well-developed root systems were not attained and root initiation percentages should be increased if the system is to become commercially feasible.

  10. The study of plant tissue by digital microscopy methods

    NASA Astrophysics Data System (ADS)

    Chirskaya, V. V.; Margaryants, N. B.; Zhukova, E. V.

    2014-09-01

    Results of the study of potato tuber (Solanum tuberosum L.) periderm with the use of digital microscopy methods are considered. A light microscope was used for diagnostics of periderm surface and recording of the images of studied sections. High-resolving full-field optical coherence microscopy ensured obtaining tomograms images of periderm texture in depth. The scanning depth was 32 μm. Tomograms (B-scans) of surfaces with normal structure of periderm upper layer in the area of mechanic damage of external protective tissues and also in the area of growth caused by a fungal disease are presented. Tomograms resolution by depth and in lateral directions is 1 μm.

  11. Plant tissue hybrid electrode for determination of phosphate and fluoride

    SciTech Connect

    Schubert, F.; Renneberg, R.; Scheller, F.W.; Kirstein, L.

    1984-08-01

    A biosensor for inorganic phosphate and fluoride has been developed by coupling a potato (Solanum tuberosum) tissue slice and immobilized glucose oxidase with a Clark oxygen electrode. Measurement is based on the inhibition by either ion of potato acid phosphates catalyzed glucose 6-phosphate hydrolysis. The precision is 1.7% and 6.5% and the lower detection limit 2.5 X 10/sup -5/ M and 1 X 10/sup -4/ M for phosphate and fluoride, respectively. For phosphate determination the hybrid sensor is stable for 28 days or 300 assays. With a higher limit of detection the sensor can be applied in a commercial enzyme electrode based device. Its application for phosphate determination in fertilizer and urine samples is described.

  12. Experimental investigation of buried tritium in plant and animal tissues

    SciTech Connect

    Kim, S. B.; Workman, W. J. G.; Davis, P. A.

    2008-07-15

    Buried exchangeable tritium appears as part of organically bound tritium (OBT) in the traditional experimental determination of OBT. Since buried tritium quickly exchanges with hydrogen atoms in the body following ingestion, assuming that it is part of OBT rather than part of tritiated water (HTO) could result in a significant overestimate of the ingestion dose. This paper documents an experimental investigation into the existence, amount and significance of buried tritium in plant and fish samples. OBT concentrations in the samples were determined in the traditional way and also following denaturing with five chemical solutions that break down large molecules and expose buried tritium to exchange with free hydrogen atoms. A comparison of the OBT concentrations before and after denaturing, together with the concentration of HTO in the supernatant obtained after denaturing, suggests that buried OBT may exist but makes up less than 5% of the OBT concentration in plants and at most 20% of the OBT concentration in fish. The effects of rinse time and rinse water volumes were investigated to optimize the removal of exchangeable OBT from the samples. (authors)

  13. Shifts in Aboveground Biomass Allocation Patterns of Dominant Shrub Species across a Strong Environmental Gradient

    PubMed Central

    Kumordzi, Bright B.; Gundale, Michael J.; Nilsson, Marie-Charlotte; Wardle, David A.

    2016-01-01

    Most plant biomass allocation studies have focused on allocation to shoots versus roots, and little is known about drivers of allocation for aboveground plant organs. We explored the drivers of within-and between-species variation of aboveground biomass allocation across a strong environmental resource gradient, i.e., a long-term chronosequence of 30 forested islands in northern Sweden across which soil fertility and plant productivity declines while light availability increases. For each of the three coexisting dominant understory dwarf shrub species on each island, we estimated the fraction of the total aboveground biomass produced year of sampling that was allocated to sexual reproduction (i.e., fruits), leaves and stems for each of two growing seasons, to determine how biomass allocation responded to the chronosequence at both the within-species and whole community levels. Against expectations, within-species allocation to fruits was least on less fertile islands, and allocation to leaves at the whole community level was greatest on intermediate islands. Consistent with expectations, different coexisting species showed contrasting allocation patterns, with the species that was best adapted for more fertile conditions allocating the most to vegetative organs, and with its allocation pattern showing the strongest response to the gradient. Our study suggests that co-existing dominant plant species can display highly contrasting biomass allocations to different aboveground organs within and across species in response to limiting environmental resources within the same plant community. Such knowledge is important for understanding how community assembly, trait spectra, and ecological processes driven by the plant community vary across environmental gradients and among contrasting ecosystems. PMID:27270445

  14. Shifts in Aboveground Biomass Allocation Patterns of Dominant Shrub Species across a Strong Environmental Gradient.

    PubMed

    Kumordzi, Bright B; Gundale, Michael J; Nilsson, Marie-Charlotte; Wardle, David A

    2016-01-01

    Most plant biomass allocation studies have focused on allocation to shoots versus roots, and little is known about drivers of allocation for aboveground plant organs. We explored the drivers of within-and between-species variation of aboveground biomass allocation across a strong environmental resource gradient, i.e., a long-term chronosequence of 30 forested islands in northern Sweden across which soil fertility and plant productivity declines while light availability increases. For each of the three coexisting dominant understory dwarf shrub species on each island, we estimated the fraction of the total aboveground biomass produced year of sampling that was allocated to sexual reproduction (i.e., fruits), leaves and stems for each of two growing seasons, to determine how biomass allocation responded to the chronosequence at both the within-species and whole community levels. Against expectations, within-species allocation to fruits was least on less fertile islands, and allocation to leaves at the whole community level was greatest on intermediate islands. Consistent with expectations, different coexisting species showed contrasting allocation patterns, with the species that was best adapted for more fertile conditions allocating the most to vegetative organs, and with its allocation pattern showing the strongest response to the gradient. Our study suggests that co-existing dominant plant species can display highly contrasting biomass allocations to different aboveground organs within and across species in response to limiting environmental resources within the same plant community. Such knowledge is important for understanding how community assembly, trait spectra, and ecological processes driven by the plant community vary across environmental gradients and among contrasting ecosystems. PMID:27270445

  15. Enhanced electroporation in plant tissues via low frequency pulsed electric fields: influence of cytoplasmic streaming.

    PubMed

    Asavasanti, Suvaluk; Stroeve, Pieter; Barrett, Diane M; Jernstedt, Judith A; Ristenpart, William D

    2012-01-01

    Pulsed electric fields (PEF) are known to be effective at permeabilizing plant tissues. Prior research has demonstrated that lower pulse frequencies induce higher rates of permeabilization, but the underlying reason for this response is unclear. Intriguingly, recent microscopic observations with onion tissues have also revealed a correlation between PEF frequency and the subsequent speed of intracellular convective motion, i.e., cytoplasmic streaming. In this paper, we investigate the effect of cytoplasmic streaming on the efficacy of plant tissue permeabilization via PEF. Onion tissue samples were treated with Cytochalasin B, a known inhibitor of cytoplasmic streaming, and changes in cellular integrity and viability were measured over a wide range of frequencies and field strengths. We find that at low frequencies (f < 1 Hz), the absence of cytoplasmic streaming results in a 19% decrease in the conductivity disintegration index compared with control samples. Qualitatively, similar results were observed using a microscopic cell viability assay. The results suggest that at low frequencies convection plays a statistically significant role in distributing more conductive fluid throughout the tissue, making subsequent pulses more efficacious. The key practical implication is that PEF pretreatment at low frequency can increase the rate of tissue permeabilization in dehydration or extraction processes, and that the treatment will be most effective when cytoplasmic streaming is most active, i.e., with freshly prepared plant tissues. PMID:22246974

  16. Marking and retention of harlequin bug, Murgantia histrionica (Hahn) (Hemiptera: Pentatomidae), on pheromone baited and unbaited plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Harlequin bug (HB) is an important pest of cole crops in the USA. The sap-sucking adults and nymphs feed on aboveground plant tissues, and can seriously damage the host. Current control measures on cole crops target mainly lepidopteran pests, and the products generally used do not control harlequin ...

  17. A Protocol for Rapid, Measurable Plant Tissue Culture Using Stem Disc Meristem Micropropagation of Garlic ("Allium Sativum L.")

    ERIC Educational Resources Information Center

    Peat, Gerry; Jones, Meriel

    2012-01-01

    Plant tissue culture is becoming an important technique for the mass propagation of plants. Problems with existing techniques, such as slow growth and contamination, have restricted the practical work in plant tissue culture carried out in schools. The new protocol using garlic meristematic stem discs explained in this article addresses many of…

  18. Root herbivore effects on aboveground multitrophic interactions: patterns, processes and mechanisms.

    PubMed

    Soler, Roxina; Van der Putten, Wim H; Harvey, Jeffrey A; Vet, Louise E M; Dicke, Marcel; Bezemer, T Martijn

    2012-06-01

    In terrestrial food webs, the study of multitrophic interactions traditionally has focused on organisms that share a common domain, mainly above ground. In the last two decades, it has become clear that to further understand multitrophic interactions, the barrier between the belowground and aboveground domains has to be crossed. Belowground organisms that are intimately associated with the roots of terrestrial plants can influence the levels of primary and secondary chemistry and biomass of aboveground plant parts. These changes, in turn, influence the growth, development, and survival of aboveground insect herbivores. The discovery that soil organisms, which are usually out of sight and out of mind, can affect plant-herbivore interactions aboveground raised the question if and how higher trophic level organisms, such as carnivores, could be influenced. At present, the study of above-belowground interactions is evolving from interactions between organisms directly associated with the plant roots and shoots (e.g., root feeders - plant - foliar herbivores) to interactions involving members of higher trophic levels (e.g., parasitoids), as well as non-herbivorous organisms (e.g., decomposers, symbiotic plant mutualists, and pollinators). This multitrophic approach linking above- and belowground food webs aims at addressing interactions between plants, herbivores, and carnivores in a more realistic community setting. The ultimate goal is to understand the ecology and evolution of species in communities and, ultimately how community interactions contribute to the functioning of terrestrial ecosystems. Here, we summarize studies on the effects of root feeders on aboveground insect herbivores and parasitoids and discuss if there are common trends. We discuss the mechanisms that have been reported to mediate these effects, from changes in concentrations of plant nutritional quality and secondary chemistry to defense signaling. Finally, we discuss how the traditional

  19. Observations on the measurement of total antimony and antimony species in algae, plant and animal tissues.

    PubMed

    Foster, S; Maher, W; Krikowa, F; Telford, K; Ellwood, M

    2005-12-01

    This paper describes our experiences with undertaking measurements of total antimony and antimony speciation in algae, plant and animal tissues. Digestion with nitric acid alone is suitable to release antimony from animal tissues. When organisms have high silica contents, e.g. some plants and algae, the addition of tetrafluorboric acid is required to dissolve silica as some antimony is retained by silica in extracts. Antimony in digested extracts is present as Sb5+ and hydride generation procedures can be used to determine total antimony concentrations, as total antimony in extracts will not be under estimated. Relatively non-aggressive solvents such as water, dilute nitric acid, sodium hydroxide and enzymes remove highly variable amounts of antimony (2-84%) from algae, plant and animal tissues. Addition of Sb3+ and Sb5+ to NIST CRM 1572 Citrus Leaves, pre- and post-extraction with water showed that Sb3+ is oxidised to Sb5+ while Sb5+ is redistributed amongst binding sites giving rise to artefacts. DOLT-2 and algae extracts indicated the presence of only inorganic antimony. A moss sample had inorganic antimony and a number of unknown antimony species in extracts. Future studies should explore the nature of the binding of antimony in tissues as solvents commonly used to extract metals and metalloids from algae, plant and animal tissues are not appropriate. PMID:16307074

  20. A fully automatable enzymatic method for DNA extraction from plant tissues

    PubMed Central

    Manen, Jean-François; Sinitsyna, Olga; Aeschbach, Lorène; Markov, Alexander V; Sinitsyn, Arkady

    2005-01-01

    Background DNA extraction from plant tissues, unlike DNA isolation from mammalian tissues, remains difficult due to the presence of a rigid cell wall around the plant cells. Currently used methods inevitably require a laborious mechanical grinding step, necessary to disrupt the cell wall for the release of DNA. Results Using a cocktail of different carbohydrases, a method was developed that enables a complete digestion of the plant cell walls and subsequent DNA release. Optimized conditions for the digestion reaction minimize DNA shearing and digestion, and maximize DNA release from the plant cell. The method gave good results in 125 of the 156 tested species. Conclusion In combination with conventional DNA isolation techniques, the new enzymatic method allows to obtain high-yield, high-molecular weight DNA, which can be used for many applications, including genome characterization by AFLP, RAPD and SSR. Automation of the protocol (from leaf disks to DNA) is possible with existing workstations. PMID:16269076

  1. Lignin oxidation product and carbohydrate composition of plant tissues from the south-eastern united states

    NASA Astrophysics Data System (ADS)

    Alberts, James J.; Price, Mary T.; Lewis, Sharon

    1991-09-01

    Twenty-one samples of woody and non-woody angiosperm and gymnosperm tissue from plants dominant in south-eastern U.S. coastal ecosystems were analysed for the distribution of CuO oxidation products and neutral monosaccharides derived from acid hydrolysis of the tissues. Phenolic oxidation products gave the same general distributions as reported for plant species in the Pacific north-west, Buzzards Bay, MA, and the western Gulf of Mexico regions of the U.S. However, monosaccharides derived from these plants had generally lower total yields and wider ranges of weight % distributions than the plants from the other regions. Thus, the phenolic oxidation products appear to be a valid indicator of terrestrial carbon source terms across a wide geographical and climatic area; however, neutral monosaccharide distributions must be used with caution when determining source term.

  2. Plant development. Integration of growth and patterning during vascular tissue formation in Arabidopsis.

    PubMed

    De Rybel, Bert; Adibi, Milad; Breda, Alice S; Wendrich, Jos R; Smit, Margot E; Novák, Ondřej; Yamaguchi, Nobutoshi; Yoshida, Saiko; Van Isterdael, Gert; Palovaara, Joakim; Nijsse, Bart; Boekschoten, Mark V; Hooiveld, Guido; Beeckman, Tom; Wagner, Doris; Ljung, Karin; Fleck, Christian; Weijers, Dolf

    2014-08-01

    Coordination of cell division and pattern formation is central to tissue and organ development, particularly in plants where walls prevent cell migration. Auxin and cytokinin are both critical for division and patterning, but it is unknown how these hormones converge upon tissue development. We identify a genetic network that reinforces an early embryonic bias in auxin distribution to create a local, nonresponding cytokinin source within the root vascular tissue. Experimental and theoretical evidence shows that these cells act as a tissue organizer by positioning the domain of oriented cell divisions. We further demonstrate that the auxin-cytokinin interaction acts as a spatial incoherent feed-forward loop, which is essential to generate distinct hormonal response zones, thus establishing a stable pattern within a growing vascular tissue. PMID:25104393

  3. On the genetic control of planar growth during tissue morphogenesis in plants.

    PubMed

    Enugutti, Balaji; Kirchhelle, Charlotte; Schneitz, Kay

    2013-06-01

    Tissue morphogenesis requires extensive intercellular communication. Plant organs are composites of distinct radial cell layers. A typical layer, such as the epidermis, is propagated by stereotypic anticlinal cell divisions. It is presently unclear what mechanisms coordinate cell divisions relative to the plane of a layer, resulting in planar growth and maintenance of the layer structure. Failure in the regulation of coordinated growth across a tissue may result in spatially restricted abnormal growth and the formation of a tumor-like protrusion. Therefore, one way to approach planar growth control is to look for genetic mutants that exhibit localized tumor-like outgrowths. Interestingly, plants appear to have evolved quite robust genetic mechanisms that govern these aspects of tissue morphogenesis. Here we provide a short summary of the current knowledge about the genetics of tumor formation in plants and relate it to the known control of coordinated cell behavior within a tissue layer. We further portray the integuments of Arabidopsis thaliana as an excellent model system to study the regulation of planar growth. The value of examining this process in integuments was established by the recent identification of the Arabidopsis AGC VIII kinase UNICORN as a novel growth suppressor involved in the regulation of planar growth and the inhibition of localized ectopic growth in integuments and other floral organs. An emerging insight is that misregulation of central determinants of adaxial-abaxial tissue polarity can lead to the formation of spatially restricted multicellular outgrowths in several tissues. Thus, there may exist a link between the mechanisms regulating adaxial-abaxial tissue polarity and planar growth in plants. PMID:22983223

  4. 49 CFR 195.307 - Pressure testing aboveground breakout tanks.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... (incorporated by reference, see § 195.3). (d) For aboveground atmospheric pressure breakout tanks constructed of... 49 Transportation 3 2014-10-01 2014-10-01 false Pressure testing aboveground breakout tanks. 195... SAFETY TRANSPORTATION OF HAZARDOUS LIQUIDS BY PIPELINE Pressure Testing § 195.307 Pressure...

  5. 49 CFR 195.307 - Pressure testing aboveground breakout tanks.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... (incorporated by reference, see § 195.3). (d) For aboveground atmospheric pressure breakout tanks constructed of... 49 Transportation 3 2011-10-01 2011-10-01 false Pressure testing aboveground breakout tanks. 195... SAFETY TRANSPORTATION OF HAZARDOUS LIQUIDS BY PIPELINE Pressure Testing § 195.307 Pressure...

  6. 49 CFR 195.307 - Pressure testing aboveground breakout tanks.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... (incorporated by reference, see § 195.3). (d) For aboveground atmospheric pressure breakout tanks constructed of... 49 Transportation 3 2010-10-01 2010-10-01 false Pressure testing aboveground breakout tanks. 195... SAFETY TRANSPORTATION OF HAZARDOUS LIQUIDS BY PIPELINE Pressure Testing § 195.307 Pressure...

  7. 49 CFR 195.307 - Pressure testing aboveground breakout tanks.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... (incorporated by reference, see § 195.3). (d) For aboveground atmospheric pressure breakout tanks constructed of... 49 Transportation 3 2012-10-01 2012-10-01 false Pressure testing aboveground breakout tanks. 195... SAFETY TRANSPORTATION OF HAZARDOUS LIQUIDS BY PIPELINE Pressure Testing § 195.307 Pressure...

  8. 49 CFR 195.307 - Pressure testing aboveground breakout tanks.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... (incorporated by reference, see § 195.3). (d) For aboveground atmospheric pressure breakout tanks constructed of... 49 Transportation 3 2013-10-01 2013-10-01 false Pressure testing aboveground breakout tanks. 195... SAFETY TRANSPORTATION OF HAZARDOUS LIQUIDS BY PIPELINE Pressure Testing § 195.307 Pressure...

  9. Landfill impacts on aquatic plant communities and tissue metal levels at Indiana Dunes National Lakeshore

    SciTech Connect

    Stewart, P.M.; Scribailo, R.W.

    1995-12-31

    One important environmental issue facing Northwest Indiana and park management at Indiana Dunes National Lakeshore (INOU) is the contamination of water, sediment and biota by persistent toxic substances. Aquatic plant communities were used to evaluate the water/organismal quality of the Grand Calumet Lagoons and two dunal ponds (pannes) at Gary, Indiana, which are partially located in the Miller Woods Unit of INDU. The lagoon is divided into several areas, the USX Lagoon is located between sections of a large industrial landfill (steel slag and other material). The Marquette Lagoon is located further away from the landfill and tends to be upgradient from the landfill. The West Panne (WP) is located next to the landfill, while the East Panne (EP) is separated from the landfill and the WP by a high dune ridge. Plant populations shift toward fewer submergent aquatics, with a higher abundance of tolerant taxa in the western section of the USX Lagoon. These differences are supported by cluster analysis. Heavy metals in root tissue of Scirpus americanus and other plant species from the pannes were significantly higher than those found in shoots. Shoot tissue metal levels in plants collected from the lagoons were higher than root tissue metal levels. The WP site has the most elevated tissue metal levels for most metals assayed, while the EP site shows similar contaminant levels. The plant distributions observed and tissue metal concentrations measured suggest that INDU`s aquatic plant community has been affected by the industrial landfill and that there exists a hydrological connection between the ponds.

  10. Belowground induction by Delia radicum or phytohormones affect aboveground herbivore communities on field-grown broccoli

    PubMed Central

    Pierre, S. P.; Dugravot, S.; Hervé, M. R.; Hassan, H. M.; van Dam, N. M.; Cortesero, A. M.

    2013-01-01

    Induced plant defence in response to phytophagous insects is a well described phenomenon. However, so far little is known about the effect of induced plant responses on subsequently colonizing herbivores in the field. Broccoli plants were induced in the belowground compartment using (i) infestation by the root-herbivore Delia radicum, (ii) root application of jasmonic acid (JA) or (iii) root application of salicylic acid (SA). The abundance of D. radicum and six aboveground herbivores displaying contrasting levels of host specialization were surveyed for 5 weeks. Our study showed that the response of herbivores was found to differ from one another, depending on the herbivore species, its degree of specialization and the root treatment. The abundance of the root herbivore D. radicum and particularly the number of emerging adults was decreased by both phytohormone treatments, while the number of D. radicum eggs was increased on conspecific infested plants. The root infestation exhibited moderate effects on the aboveground community. The abundance of the aphid Brevicoryne brassicae was strongly increased on D. radicum infested plants, but the other species were not impacted. Root hormone applications exhibited a strong effect on the abundance of specialist foliar herbivores. A higher number of B. brassicae and Pieris brassicae and a lower number of Plutella xylostella were found on JA treated plants. On SA treated plants we observed a decrease of the abundance of B. brassicae, Pi. rapae, and P. xylostella. Surprisingly, generalist species, Mamestra brassicae and Myzus persicae were not affected by root induction treatments. Finally, root treatments had no significant effect on either glucosinolate (GLS) profiles of the heads or on plant quality parameters. These results are discussed from the perspective of below- aboveground interactions and adaptations of phytophagous insects to induced plant responses according to their trophic specialization level. PMID:23970888

  11. Carbon Fluxes between Primary Metabolism and Phenolic Pathway in Plant Tissues under Stress

    PubMed Central

    Caretto, Sofia; Linsalata, Vito; Colella, Giovanni; Mita, Giovanni; Lattanzio, Vincenzo

    2015-01-01

    Higher plants synthesize an amazing diversity of phenolic secondary metabolites. Phenolics are defined secondary metabolites or natural products because, originally, they were considered not essential for plant growth and development. Plant phenolics, like other natural compounds, provide the plant with specific adaptations to changing environmental conditions and, therefore, they are essential for plant defense mechanisms. Plant defensive traits are costly for plants due to the energy drain from growth toward defensive metabolite production. Being limited with environmental resources, plants have to decide how allocate these resources to various competing functions. This decision brings about trade-offs, i.e., promoting some functions by neglecting others as an inverse relationship. Many studies have been carried out in order to link an evaluation of plant performance (in terms of growth rate) with levels of defense-related metabolites. Available results suggest that environmental stresses and stress-induced phenolics could be linked by a transduction pathway that involves: (i) the proline redox cycle; (ii) the stimulated oxidative pentose phosphate pathway; and, in turn, (iii) the reduced growth of plant tissues. PMID:26556338

  12. Regional contingencies in the relationship between aboveground Bbomass and litter in the world’s grasslands

    USGS Publications Warehouse

    O’Halloran, Lydia R.; Borer, Elizabeth T.; Seabloom, Eric W.; MacDougall, Andrew S.; Cleland, Elsa E.; McCulley, Rebecca L.; Hobbie, Sarah; Harpole, W. Stan; DeCrappeo, Nicole M.; Chu, Cheng-Jin; Bakker, Jonathan D.; Davies, Kendi F.; Du, Guozhen; Firn, Jennifer; Hagenah, Nicole; Hofmockel, Kirsten S.; Knops, Johannes M.H.; Li, Wei; Melbourne, Brett A.; Morgan, John W.; Orrock, John L.; Prober, Suzanne M.; Stevens, Carly J.

    2013-01-01

    Based on regional-scale studies, aboveground production and litter decomposition are thought to positively covary, because they are driven by shared biotic and climatic factors. Until now we have been unable to test whether production and decomposition are generally coupled across climatically dissimilar regions, because we lacked replicated data collected within a single vegetation type across multiple regions, obfuscating the drivers and generality of the association between production and decomposition. Furthermore, our understanding of the relationships between production and decomposition rests heavily on separate meta-analyses of each response, because no studies have simultaneously measured production and the accumulation or decomposition of litter using consistent methods at globally relevant scales. Here, we use a multi-country grassland dataset collected using a standardized protocol to show that live plant biomass (an estimate of aboveground net primary production) and litter disappearance (represented by mass loss of aboveground litter) do not strongly covary. Live biomass and litter disappearance varied at different spatial scales. There was substantial variation in live biomass among continents, sites and plots whereas among continent differences accounted for most of the variation in litter disappearance rates. Although there were strong associations among aboveground biomass, litter disappearance and climatic factors in some regions (e.g. U.S. Great Plains), these relationships were inconsistent within and among the regions represented by this study. These results highlight the importance of replication among regions and continents when characterizing the correlations between ecosystem processes and interpreting their global-scale implications for carbon flux. We must exercise caution in parameterizing litter decomposition and aboveground production in future regional and global carbon models as their relationship is complex.

  13. Improved allometric models to estimate the aboveground biomass of tropical trees.

    PubMed

    Chave, Jérôme; Réjou-Méchain, Maxime; Búrquez, Alberto; Chidumayo, Emmanuel; Colgan, Matthew S; Delitti, Welington B C; Duque, Alvaro; Eid, Tron; Fearnside, Philip M; Goodman, Rosa C; Henry, Matieu; Martínez-Yrízar, Angelina; Mugasha, Wilson A; Muller-Landau, Helene C; Mencuccini, Maurizio; Nelson, Bruce W; Ngomanda, Alfred; Nogueira, Euler M; Ortiz-Malavassi, Edgar; Pélissier, Raphaël; Ploton, Pierre; Ryan, Casey M; Saldarriaga, Juan G; Vieilledent, Ghislain

    2014-10-01

    Terrestrial carbon stock mapping is important for the successful implementation of climate change mitigation policies. Its accuracy depends on the availability of reliable allometric models to infer oven-dry aboveground biomass of trees from census data. The degree of uncertainty associated with previously published pantropical aboveground biomass allometries is large. We analyzed a global database of directly harvested trees at 58 sites, spanning a wide range of climatic conditions and vegetation types (4004 trees ≥ 5 cm trunk diameter). When trunk diameter, total tree height, and wood specific gravity were included in the aboveground biomass model as covariates, a single model was found to hold across tropical vegetation types, with no detectable effect of region or environmental factors. The mean percent bias and variance of this model was only slightly higher than that of locally fitted models. Wood specific gravity was an important predictor of aboveground biomass, especially when including a much broader range of vegetation types than previous studies. The generic tree diameter-height relationship depended linearly on a bioclimatic stress variable E, which compounds indices of temperature variability, precipitation variability, and drought intensity. For cases in which total tree height is unavailable for aboveground biomass estimation, a pantropical model incorporating wood density, trunk diameter, and the variable E outperformed previously published models without height. However, to minimize bias, the development of locally derived diameter-height relationships is advised whenever possible. Both new allometric models should contribute to improve the accuracy of biomass assessment protocols in tropical vegetation types, and to advancing our understanding of architectural and evolutionary constraints on woody plant development. PMID:24817483

  14. Cadmium uptake in above-ground parts of lettuce (Lactuca sativa L.).

    PubMed

    Tang, Xiwang; Pang, Yan; Ji, Puhui; Gao, Pengcheng; Nguyen, Thanh Hung; Tong, Yan'an

    2016-03-01

    Because of its high Cd uptake and translocation, lettuce is often used in Cd contamination studies. However, there is a lack of information on Cd accumulation in the above-ground parts of lettuce during the entire growing season. In this study, a field experiment was carried out in a Cd-contaminated area. Above-ground lettuce parts were sampled, and the Cd content was measured using a flame atomic absorption spectrophotometer (AAS). The results showed that the Cd concentration in the above-ground parts of lettuce increased from 2.70 to 3.62mgkg(-1) during the seedling stage, but decreased from 3.62 to 2.40mgkg(-1) during organogenesis and from 2.40 to 1.64mgkg(-1) during bolting. The mean Cd concentration during the seedling stage was significantly higher than that during organogenesis (a=0.05) and bolting (a=0.01). The Cd accumulation in the above-ground parts of an individual lettuce plant could be described by a sigmoidal curve. Cadmium uptake during organogenesis was highest (80% of the total), whereas that during bolting was only 4.34%. This research further reveals that for Rome lettuce: (1) the highest Cd content of above-ground parts occurred at the end of the seedling phase; (2) the best harvest time with respect to Cd phytoaccumulation is at the end of the organogenesis stage; and (3) the organogenesis stage is the most suitable time to enhance phytoaccumulation efficiency by adjusting the root:shoot ratio. PMID:26685781

  15. DNA Changes in Tissues Entrapped in Plant Resins (the Precursors of Amber)

    NASA Astrophysics Data System (ADS)

    Rogers, S. O.; Langenegger, K.; Holdenrieder, O.

    There have been many reports characterizing DNA from amber, which is a fossil version of plant resin. Here we report an investigation of the effects of plant resin (from Pseudotsuga menziesii) and drying conditions on the preservation of DNA in biological tissues. We examined the degree of degradation of the DNA by agarose gel electrophoresis of extracted DNA, by polymerase chain reaction, and by DNA sequencing. The plant resin alone appeared to cause little or no damage to DNA. Tissue immersed in plant resin that dried rapidly (exposed to sunlight) contained DNA with little apparent damage. Tissue immersed in the resin that was dried slowly (in shade without sunlight) contained DNA with some degradation (3.5% nucleotide changes). The tissue that was immersed in the resin that was constantly hydrated (by immersion in water) yielded DNA that was severely damaged (50-62% nucleotide changes). Transversions outnumbered transitions in these samples by a ratio of 1.4 : 1. A piece of Baltic amber immersed in water for 5days appeared to be impervious to the water. Thus amber inclusions that initially dried rapidly have the potential to yield undamaged DNA. Those that dried slowly may contain damaged DNA and may be unsuitable for phylogenetic and other studies.

  16. Microwave-Assisted Solvent Extraction and Analysis of Shikimic Acid from Plant Tissues

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A simple method using microwave-assisted extraction (MWAE) using water as the extraction solvent was developed for the determination of shikimic acid in plant tissue of Brachiaria decumbens Stapf, an important Poaceae forage and weed species widely spread in agricultural and non-agricultural areas t...

  17. An Alternative Gelling Agent for Culture and Studies of Nematodes, Bacteria, Fungi, and Plant Tissues

    PubMed Central

    Ko, M. P.; Van Gundy, S. D.

    1988-01-01

    Pluronic F127 polyol, a block copolymer of propylene oxide and ethylene oxide, was studied as an alternative to agar in culture media for nematodes, bacteria, fungi, actinomycetes, and plant tissues or seedlings, At a polyol concentration of 20% w/v, the culture media, semi-solid at room temperature (22 C) but liquid at lower temperatures, had minimal effects on the test organisms. Most of the fungi and bacteria grew as well in 20% polyol as in 1.5% agar media; however, various species of nematodes and plant seedlings or tissues exhibited differential sensitivities to different concentrations of the polyol. In cases where the organisms were unaffected, the polyol media had certain advantages over agar, including greater transparency and less contamination under nonaseptic conditions. Polyol media have potentially greater ease for recovery of embedded organisms or tissues inside the media by merely shifting to lower temperatures. PMID:19290241

  18. An Improved Method for Using Electrolyte Leakage to Assess Membrane Competence in Plant Tissues 1

    PubMed Central

    Whitlow, Thomas H.; Bassuk, Nina L.; Ranney, Thomas G.; Reichert, Deborah L.

    1992-01-01

    A new expression for ion leakage from plant tissue, the tissue ionic conductance (gTi), is compared with electrical conductivity (EC) and a commonly used damage index (Id) to test the ability of each expression to correctly describe leakiness in two model systems representing examples of physiological processes with well-known effects on membrane permeability. In experiments in which drought-acclimated leaves were compared with nonacclimated leaves and senescing leaves were compared with nonsenescing leaves, Id contradicted our expectation that acclimated tissue would be less leaky than nonacclimated tissue, and gTi and EC confirmed this expectation. In a comparison of senescing and nonsenescing tissue, Id again contradicted our expectation that senescing tissue would be more leaky than nonsenescing, and EC and gTi were confirming. Using a diffusion analysis approach, we show that Id fails to account for variation in the concentration gradient between the tissue and the bathing solution and variation in the surface area through which efflux occurs. Furthermore, because Id is a parameter that relates treatment performance to control performance as a percentage value, it distorts the actual differences among treatments. The resulting artifacts lead to a presentation of membrane integrity which is probably incorrect. EC is a more direct measurement of net ion efflux and appears to be less vulnerable to artifact. However, because gTi is the only expression that explicitly includes chemical driving force and tissue surface area, it is the most reliable of the three expressions. PMID:16668614

  19. Light-regulated, tissue-specific immunophilins in a higher plant.

    PubMed

    Luan, S; Albers, M W; Schreiber, S L

    1994-02-01

    In addition to their application in organ transplantation, immunosuppressive drugs are valuable tools for studying signal transduction in eukaryotic cells. Using affinity chromatography, we have purified immunosuppressive drug receptors (immunophilins) from fava bean. Proteins belonging to both major classes of the immunophilin family identified from animal sources [FK506- and rapamycin-binding proteins (FKBPs) and cyclophilins] were present in this higher plant. FKBP13, the most abundant FKBP family member in leaf tissues, was not detected in root tissues, whereas other FKBPs were present in both tissues. While the abundance of cyclophilin A in leaves was similar to that in roots, cyclophilin B/C was expressed at a much higher level in leaf tissues than in root tissues. Subcellular localization of immunophilins in mesophyll cells showed that chloroplasts contained FKBP13 and cyclophilin B/C but not other members, which explains the preferential expression of these two proteins in leaves over roots. The abundance of chloroplast-localized immunophilins, FKBP13 and cyclophilin B/C, was regulated by light. Although etiolated leaves produced detectable levels of cyclophilin B/C, they did not express FKBP13. Illumination of etiolated plants dramatically increased the expression of both FKBP13 and cyclophilin B/C. The light-induced expression of FKBP13 is closely correlated with the accumulation of chlorophyll in the leaf tissue. Our findings suggest that FKBP13 and cyclophilin B/C may play a specific role in chloroplasts. PMID:7508125

  20. A critical evaluation of sample extraction techniques for enhanced proteomic analysis of recalcitrant plant tissues.

    PubMed

    Saravanan, Ramu S; Rose, Jocelyn K C

    2004-09-01

    Most published proteomics studies of bulk plant tissues use a procedure in which proteins are precipitated with trichloroacetic acid (TCA) and acetone (TCA-A), but few attempts have been made to contrast this approach in a systematic way with alternative methods against a spectrum of tissues. To address this, TCA-A was compared with another acetone-based protocol (TCA-B) or a phenol (Phe)-based method, targeting a range of tomato tissues and three species of fruits that contain high levels of contaminating compounds: banana, avocado and orange. The Phe method gave a higher protein yield and typically greater resolution and spot intensity, particularly with extracts from tissues containing high levels of soluble polysaccharides. The methods also generated remarkably different two-dimensional gel electrophoresis (2-DE) protein spot patterns. Peptide mass fingerprinting was used to identify polypeptides that were common to multiple extracts or uniquely present in one extract type. While no clear pattern emerged to explain the basis for the differential protein extraction, it was noted that the Phe method showed enhanced extraction of glycoproteins. These results suggest that the Phe protocol is highly effective with more recalcitrant tissues and that a combination of TCA-A and Phe methods provides enhanced 2-DE based proteomic analyses of most plant tissues. PMID:15352226

  1. Lactococcus lactis Metabolism and Gene Expression during Growth on Plant Tissues

    PubMed Central

    Golomb, Benjamin L.

    2014-01-01

    Lactic acid bacteria have been isolated from living, harvested, and fermented plant materials; however, the adaptations these bacteria possess for growth on plant tissues are largely unknown. In this study, we investigated plant habitat-specific traits of Lactococcus lactis during growth in an Arabidopsis thaliana leaf tissue lysate (ATL). L. lactis KF147, a strain originally isolated from plants, exhibited a higher growth rate and reached 7.9-fold-greater cell densities during growth in ATL than the dairy-associated strain L. lactis IL1403. Transcriptome profiling (RNA-seq) of KF147 identified 853 induced and 264 repressed genes during growth in ATL compared to that in GM17 laboratory culture medium. Genes induced in ATL included those involved in the arginine deiminase pathway and a total of 140 carbohydrate transport and metabolism genes, many of which are involved in xylose, arabinose, cellobiose, and hemicellulose metabolism. The induction of those genes corresponded with L. lactis KF147 nutrient consumption and production of metabolic end products in ATL as measured by gas chromatography-time of flight mass spectrometry (GC-TOF/MS) untargeted metabolomic profiling. To assess the importance of specific plant-inducible genes for L. lactis growth in ATL, xylose metabolism was targeted for gene knockout mutagenesis. Wild-type L. lactis strain KF147 but not an xylA deletion mutant was able to grow using xylose as the sole carbon source. However, both strains grew to similarly high levels in ATL, indicating redundancy in L. lactis carbohydrate metabolism on plant tissues. These findings show that certain strains of L. lactis are well adapted for growth on plants and possess specific traits relevant for plant-based food, fuel, and feed fermentations. PMID:25384484

  2. Plant nutrients do not covary with soil nutrients under changing climatic conditions

    NASA Astrophysics Data System (ADS)

    Luo, Wentao; Elser, James J.; Lü, Xiao-Tao; Wang, Zhengwen; Bai, Edith; Yan, Caifeng; Wang, Chao; Li, Mai-He; Zimmermann, Niklaus E.; Han, Xingguo; Xu, Zhuwen; Li, Hui; Wu, Yunna; Jiang, Yong

    2015-08-01

    Nitrogen (N) and phosphorus (P) play vital roles in plant growth and development. Yet how climate regimes and soil fertility influence plant N and P stoichiometry is not well understood, especially in the belowground plant parts. Here we investigated plant aboveground and belowground N and P concentrations ([N] and [P]) and their stoichiometry in three dominant genera along a 2200 km long climatic gradient in northern China. Results showed that temperature explained more variation of [N] and [P] in C4 plants, whereas precipitation exerted a stronger influence on [N] and [P] in C3 plants. Both plant aboveground and belowground [N] and [P] increased with decreasing precipitation, and increasing temperatures yet were negatively correlated with soil [N] and [P]. Plant N:P ratios were unrelated with all climate and soil variables. Plant aboveground and belowground [N] followed an allometric scaling relationship, but the allocation of [P] was isometric. These results imply that internal processes stabilize plant N:P ratios and hence tissue N:P ratios may not be an effective parameter for predicting plant nutrient limitation. Our results also imply that past positive relationships between plant and nutrient stocks may be challenged under changing climatic conditions. While any modeling would need to be able to replicate currently observed relationships, it is conceivable that some relationships, such as those between temperature or rainfall and carbon:nutrient ratios, should be different under changing climatic conditions.

  3. Detection and Quantitation of Octopine in Normal Plant Tissue and in Crown Gall Tumors

    PubMed Central

    Johnson, Roosevelt; Guderian, Ronald H.; Eden, Francine; Chilton, Mary-Dell; Gordon, Milton P.; Nester, Eugene W.

    1974-01-01

    Octopine has been detected in normal tobacco leaf and stem tissue, normal sunflower stem tissue, pinto bean leaves, and normal tobacco callus tissue in culture. Octopine was identified in extracts by means of electrophoresis and chromatography in several solvent systems. Tobacco and sunflower tumor lines induced by various strains of Agrobacterium tumefaciens were found to contain from 1 to 240 times as much octopine as the normal plant tissues examined. Several strains of A. tumefaciens produce undifferentiated tobacco tumors containing high levels of octopine, but produce undifferentiated sunflower tumors containing normal levels of octopine and high levels of arginine. Further, strain CGIC of A. tumefaciens produces in tobacco an undifferentiated tumor which contains high levels of octopine and a teratoma which contains normal levels of octopine. This evidence shows that there is no consistent relationship between the causative strain of A. tumefaciens and the octopine content of the resulting crown gall tumor. PMID:16592142

  4. Isolation of viable multicellular glands from tissue of the carnivorous plant, Nepenthes.

    PubMed

    Rottloff, Sandy; Mithöfer, Axel; Müller, Ute; Kilper, Roland

    2013-01-01

    Many plants possess specialized structures that are involved in the production and secretion of specific low molecular weight compounds and proteins. These structures are almost always localized on plant surfaces. Among them are nectaries or glandular trichomes. The secreted compounds are often employed in interactions with the biotic environment, for example as attractants for pollinators or deterrents against herbivores. Glands that are unique in several aspects can be found in carnivorous plants. In so-called pitcher plants of the genus Nepenthes, bifunctional glands inside the pitfall-trap on the one hand secrete the digestive fluid, including all enzymes necessary for prey digestion, and on the other hand take-up the released nutrients. Thus, these glands represent an ideal, specialized tissue predestinated to study the underlying molecular, biochemical, and physiological mechanisms of protein secretion and nutrient uptake in plants. Moreover, generally the biosynthesis of secondary compounds produced by many plants equipped with glandular structures could be investigated directly in glands. In order to work on such specialized structures, they need to be isolated efficiently, fast, metabolically active, and without contamination with other tissues. Therefore, a mechanical micropreparation technique was developed and applied for studies on Nepenthes digestion fluid. Here, a protocol is presented that was used to successfully prepare single bifunctional glands from Nepenthes traps, based on a mechanized microsampling platform. The glands could be isolated and directly used further for gene expression analysis by PCR techniques after preparation of RNA. PMID:24378909

  5. Plant Tissue Culture Development and Biotechnology, Chapter 10: Molecular Tools for Studying Plant Genetic Diversity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The ubiquitous nature of DNA is a central theme for all biology. The nucleus of each cell that makes up an organism contains genomic DNA, which is the blueprint for life. The differential expression of genes within each cell gives rise to different tissues, organs and, ultimately, different organism...

  6. A new conceptual model on the fate and controls of fresh and pyrolized plant litter decomposition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The leaching of dissolved organic matter (DOM) from fresh and pyrolyzed aboveground plant inputs to the soil is a major pathway by which decomposing aboveground plant material contributes to soil organic matter formation. Understanding how aboveground plant input chemical traits control the partiti...

  7. A method for routine measurements of total sugar and starch content in woody plant tissues.

    PubMed

    Chow, Pak S; Landhäusser, Simon M

    2004-10-01

    Several extraction and measurement methods currently employed in the determination of total sugar and starch contents in plant tissues were investigated with the view to streamline the process of total sugar and starch determination. Depending on the type and source of tissue, total sugar and starch contents estimated from samples extracted with 80% hot ethanol were significantly greater than from samples extracted with a methanol:chloroform:water solution. The residual ethanol did not interfere with the sugar and starch determination, rendering the removal of ethanol from samples unnecessary. The use of phenol-sulfuric acid with a phenol concentration of 2% provided a relatively simple and reliable colorimetric method to quantify the total soluble-sugar concentration. Performing parallel sugar assays with and without phenol was more useful for accounting for the interfering effects of other substances present in plant tissue than using chloroform. For starch determination, an enzyme mixture of 1000 U alpha-amylase and 5 U amyloglucosidase digested starch in plant tissue samples more rapidly and completely than previously recommended enzyme doses. Dilute sulfuric acid (0.005 N) was less suitable for starch digestion than enzymatic hydrolysis because the acid also broke down structural carbohydrates, resulting in overestimates of starch content. After the enzymatic digestion of starch, the glucose hydrolyzate obtained was measured with a peroxidase-glucose oxidase/o-dianisidine reagent; absorbance being read at 525 nm after the addition of sulfuric acid. With the help of this series of studies, we developed a refined and shortened method suitable for the rapid measurement of total sugar and starch contents in woody plant tissues. PMID:15294759

  8. Wounding in the plant tissue: the defense of a dangerous passage

    PubMed Central

    Savatin, Daniel V.; Gramegna, Giovanna; Modesti, Vanessa; Cervone, Felice

    2014-01-01

    Plants are continuously exposed to agents such as herbivores and environmental mechanical stresses that cause wounding and open the way to the invasion by microbial pathogens. Wounding provides nutrients to pathogens and facilitates their entry into the tissue and subsequent infection. Plants have evolved constitutive and induced defense mechanisms to properly respond to wounding and prevent infection. The constitutive defenses are represented by physical barriers, i.e., the presence of cuticle or lignin, or by metabolites that act as toxins or deterrents for herbivores. Plants are also able to sense the injured tissue as an altered self and induce responses similar to those activated by pathogen infection. Endogenous molecules released from wounded tissue may act as Damage-Associated Molecular Patterns (DAMPs) that activate the plant innate immunity. Wound-induced responses are both rapid, such as the oxidative burst and the expression of defense-related genes, and late, such as the callose deposition, the accumulation of proteinase inhibitors and of hydrolytic enzymes (i.e., chitinases and gluganases). Typical examples of DAMPs involved in the response to wounding are the peptide systemin, and the oligogalacturonides, which are oligosaccharides released from the pectic component of the cell wall. Responses to wounding take place both at the site of damage (local response) and systemically (systemic response) and are mediated by hormones such as jasmonic acid, ethylene, salicylic acid, and abscisic acid. PMID:25278948

  9. Permeabilization of plant tissues by monopolar pulsed electric fields: effect of frequency.

    PubMed

    Asavasanti, Suvaluk; Ristenpart, William; Stroeve, Pieter; Barrett, Diane M

    2011-01-01

    Pulsed electric fields (PEF) nonthermally induce cell membrane permeabilization and thereby improve dehydration and extraction efficiencies in food plant materials. Effects of electrical field strength and number of pulses on plant tissue integrity have been studied extensively. Two previous studies on the effect of pulse frequency, however, did not provide a clear view: one study suggested no effect of frequency, while the other found a greater impact on tissue integrity at lower frequency. This study establishes the effect of pulse frequency on integrity of onion tissues. Changes in electrical characteristics, ion leakage, texture parameters, and percent weight loss were quantified for a wide range of pulse frequencies under conditions of fixed field strength and pulse number. Optical microscopy and viable-cell staining provided direct visualization of effects on individual cells. The key finding is that lower frequencies (f < 1 Hz) cause more damage to tissue integrity than higher frequencies (f = 1 to 5000 Hz). Intriguingly, the optical microscopy observations demonstrate that the speed of intracellular convective motion (that is, cytoplasmic streaming) following PEF application is strongly correlated with PEF frequency. We provide the first in situ visualization of the intracellular consequence of PEF at different frequencies in a plant tissue. We hypothesize that cytoplasmic streaming plays a significant role in moving conductive ionic species from permeabilized cells to the intercellular space between plant cells, making subsequent pulses more efficacious at sufficiently low frequencies. The results suggest that decreasing the pulse frequency in PEF may minimize the number of pulses needed to achieve a desired amount of permeabilization, thus lowering the total energy consumption. Practical Application: PEF cause pores to be formed in plant cell membranes, thereby improve moisture removal and potential extraction of desirable components. This study used in

  10. New insights into the dynamics of vacuum impregnation of plant tissues and its metabolic consequences.

    PubMed

    Galindo, Federico Gómez; Yusof, Noor Liyana

    2015-04-01

    The complex and highly interconnected intercellular air spaces of plant tissues occupied by gas or native liquid has offered the possibility for impregnation with a wide range of compounds. In food processing, the development of vacuum impregnation has allowed a controlled way to introduce these compounds to the tissue structure aiming at modifying structural, nutritional, and/or functional properties as well as improving the processability of fruits and vegetables. In the last 10 years, more than 100 research articles have been published on the topic and significant insights had been gained including improved understanding of mechanisms for mass transfer as well as the development of new, fascinating industrial applications. In the recent years, our knowledge on these aspects has increased by bringing new exploration technologies for studying the impregnation of porous materials and plant cell physiology approaches to bear on the topic. The aim of this paper is to highlight some of these exciting advances. PMID:24917465

  11. The effect of chemical processing on the δ 13C value of plant tissue

    NASA Astrophysics Data System (ADS)

    Van de Water, Peter K.

    2002-04-01

    The effect of standard processing techniques on the δ 13C value of plant tissue was tested using species representing the three photosynthetic pathways, including angiosperms and gymnosperms within the C 3 taxonomic division. The species include Cowania mexicana (C 3 angiosperm), Juniperus osteosperma (C 3 gymnosperm), Opuntia spp. (crassulacean acid metabolism [CAM] angiosperm), and Atriplex canescens (C 4 angiosperm). Each species is represented by 5 plants collected at two different sites, for a total of 10 samples. The samples were processed to whole plant tissue, holocellulose, α-cellulose, and nitrocellulose. An additional process was added with the discovery of residual Ca-oxalate crystals in holocellulose samples. Both C 3 species show δ 13C values becoming 13C enriched with increased processing. The CAM representative shows the opposite trend, with 13C depletion during the progression of treatments. The greatest range of values and most inconsistent trends occur in the C 4 representative. Removal of the Ca-oxalate fraction resulted in different mean weight percentages and δ 13C values among the species. Calculated δ 13C values of the Ca-oxalate crystals show depletion from the tissue values in the two C 3 species and enrichment in the C 4 and CAM representatives. The C. mexicana samples show the greatest change between the tissue and Ca-oxalates (7.3‰) but the least mean weight percentage (11%), whereas A. canescens shows the greatest overall change, with a -2.8‰ isotopic shift and over 48% mean weight percentage. Variability within the samples undergoing each treatment remained relatively unchanged even with increased cellulose purity. This paper provides estimates of isotopic offsets necessary to correct from one treatment to another. Significant differences in δ 13C among different treatments confirm the need to state the tissue fraction analyzed when reporting δ 13C results.

  12. Tandem high-pressure freezing and quick freeze substitution of plant tissues for transmission electron microscopy.

    PubMed

    Bobik, Krzysztof; Dunlap, John R; Burch-Smith, Tessa M

    2014-01-01

    Since the 1940s transmission electron microscopy (TEM) has been providing biologists with ultra-high resolution images of biological materials. Yet, because of laborious and time-consuming protocols that also demand experience in preparation of artifact-free samples, TEM is not considered a user-friendly technique. Traditional sample preparation for TEM used chemical fixatives to preserve cellular structures. High-pressure freezing is the cryofixation of biological samples under high pressures to produce very fast cooling rates, thereby restricting ice formation, which is detrimental to the integrity of cellular ultrastructure. High-pressure freezing and freeze substitution are currently the methods of choice for producing the highest quality morphology in resin sections for TEM. These methods minimize the artifacts normally associated with conventional processing for TEM of thin sections. After cryofixation the frozen water in the sample is replaced with liquid organic solvent at low temperatures, a process called freeze substitution. Freeze substitution is typically carried out over several days in dedicated, costly equipment. A recent innovation allows the process to be completed in three hours, instead of the usual two days. This is typically followed by several more days of sample preparation that includes infiltration and embedding in epoxy resins before sectioning. Here we present a protocol combining high-pressure freezing and quick freeze substitution that enables plant sample fixation to be accomplished within hours. The protocol can readily be adapted for working with other tissues or organisms. Plant tissues are of special concern because of the presence of aerated spaces and water-filled vacuoles that impede ice-free freezing of water. In addition, the process of chemical fixation is especially long in plants due to cell walls impeding the penetration of the chemicals to deep within the tissues. Plant tissues are therefore particularly challenging, but

  13. OBLIQUE VIEW WITH ABOVEGROUND PORTION IN THE FOREGROUND. VIEW FACING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    OBLIQUE VIEW WITH ABOVE-GROUND PORTION IN THE FOREGROUND. VIEW FACING SOUTHWEST - U.S. Naval Base, Pearl Harbor, Ford Island 5-Inch Antiaircraft Battery, Battery Command Center, Ford Island, Pearl City, Honolulu County, HI

  14. NORTH ELEVATION WITH GRADUATED MEASURING POLE. ABOVEGROUND PORTION IS ON ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    NORTH ELEVATION WITH GRADUATED MEASURING POLE. ABOVE-GROUND PORTION IS ON THE LEFT. VIEW FACING SOUTH - U.S. Naval Base, Pearl Harbor, Ford Island 5-Inch Antiaircraft Battery, Battery Command Center, Ford Island, Pearl City, Honolulu County, HI

  15. PROVEN ALTERNATIVES FOR ABOVEGROUND TREATMENT OF ARSENIC IN GROUNDWATER

    EPA Science Inventory

    This report was prepared as an issue paper for the EPA Engineering Forum, summarizes experiences with proven aboveground treatment alternatives for arsenic in groundwater, and provides information on their relative performance and cost. The four technologies reviewed are: preci...

  16. Tissue culture system using a PANDA ring resonator and wavelength router for hydroponic plant.

    PubMed

    Kamoldilok, Surachart; Suwanpayak, Nathaporn; Suttirak, Saisudawan; Yupapin, Preecha P

    2012-06-01

    A novel system of nanofluidics trapping and delivery, which is known as a tissue culture system is proposed. By using the intense optical pulse(i.e., a soliton pulse) and a system constructed by a liquid core waveguide, the optical vortices (gradient optical fields/wells) can be generated, where the trapping tools in the same way as the optical tweezers in the PANDA ring resonator can be formed. By controlling the suitable parameters, the intense optical vortices can be generated within the PANDA ring resonator, in which the nanofluidics can be trapped and moved (transported) dynamically within the Tissue culture system(a wavelength router), which can be used for tissue culture and delivery in the hydroponic plant system. PMID:22411055

  17. A Transcriptome-Based Characterization of Habituation in Plant Tissue Culture1[W

    PubMed Central

    Pischke, Melissa S.; Huttlin, Edward L.; Hegeman, Adrian D.; Sussman, Michael R.

    2006-01-01

    For the last 50 years, scientists have recognized that varying ratios of the plant hormones cytokinin and auxin induce plant cells to form particular tissues: undifferentiated calli, shoot structures, root structures, or a whole plant. Proliferation of undifferentiated callus tissue, greening, and the formation of shoot structures are all cytokinin-dependent processes. Habituation refers to a naturally occurring phenomenon whereby callus cultures, upon continued passage, lose their requirement for cytokinin. Earlier studies of calli with a higher-than-normal cytokinin content indicate that overproduction of cytokinin by the culture tissues is a possible explanation for this acquired cytokinin independence. A transcriptome-based analysis of a well established habituated Arabidopsis (Arabidopsis thaliana) cell culture line was undertaken, to explore genome-wide expression changes underlying the phenomenon of habituation. Increased levels of expression of the cytokinin receptor CRE1, as well as altered levels of expression of several other genes involved in cytokinin signaling, indicated that naturally acquired deregulation of cytokinin-signaling components could play a previously unrecognized role in habituation. Up-regulation of several cytokinin oxidases, down-regulation of several known cytokinin-inducible genes, and a lack of regulation of the cytokinin synthases indicated that increases in hormone concentration may not be required for habituation. In addition, up-regulation of the homeodomain transcription factor FWA, transposon-related elements, and several DNA- and chromatin-modifying enzymes indicated that epigenetic changes contribute to the acquisition of cytokinin habituation. PMID:16489130

  18. Quantitative images of metals in plant tissues measured by laser ablation inductively coupled plasma mass spectrometry

    NASA Astrophysics Data System (ADS)

    Becker, J. S.; Dietrich, R. C.; Matusch, A.; Pozebon, D.; Dressler, V. L.

    2008-11-01

    Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was used for quantitative imaging of toxic and essential elements in thin sections (thickness of 30 or 40 μm) of tobacco plant tissues. Two-dimensional images of Mg, Fe, Mn, Zn, Cu, Cd, Rh, Pt and Pb in leaves, shoots and roots of tobacco were produced. Sections of the plant tissues (fixed onto glass slides) were scanned by a focused beam of a Nd:YAG laser in a laser ablation chamber. The ablated material was transported with argon as carrier gas to the ICP ion source at a quadrupole ICP-MS instrument. Ion intensities of the investigated elements were measured together with 13C +, 33S + and 34S + within the entire plant tissue section. Matrix matching standards (prepared using powder of dried tobacco leaves) were used to constitute calibration curves, whereas the regression coefficient of the attained calibration curves was typically 0.99. The variability of LA-ICP-MS process, sample heterogeneity and water content in the sample were corrected by using 13C + as internal standard. Quantitative imaging of the selected elements revealed their inhomogeneous distribution in leaves, shoots and roots.

  19. Asymmetric reduction of prochiral ketones to chiral alcohols catalyzed by plants tissue.

    PubMed

    Yang, Zhong-Hua; Zeng, Rong; Yang, Gai; Wang, Yu; Li, Li-Zhen; Lv, Zao-Sheng; Yao, Man; Lai, Bin

    2008-09-01

    As an important organic compound, chiral alcohols are the key chiral building blocks to many single enantiomer pharmaceuticals. Asymmetric reduction of the corresponding prochiral ketones to produce the chiral alcohols by biocatalysis is one of the most promising routes. Asymmetric reduction of different kinds of non-natural prochiral ketones catalyzed by various plants tissue was studied in this work. Acetophenone, 4'-chloroacetophenone and ethyl 4-chloroacetoacetate were chosen as the model substrates for simple ketone, halogen-containing aromatic ketone and beta-ketoesters, respectively. Apple (Malus pumila), carrot (Daucus carota), cucumber (Cucumis sativus), onion (Allium cepa), potato (Soanum tuberosum), radish (Raphanus sativus) and sweet potato (Ipomoea batatas) were chosen as the biocatalysts. It was found that these kinds of prochiral ketoness could be reduced by these plants tissue with high enantioselectivity. Both R- and S-form configuration chiral alcohols could be obtained. The e.e. and chemical yield could reach about 98 and 80% respectively for acetophenone and 4'-chloroacetophenone reduction reaction with favorable plant tissue. And the e.e. and yield for ethyl 4-chloroacetoacetate reduction reaction was about 91 and 45% respectively. PMID:18548304

  20. Spatial organization and correlation properties quantify structural changes on mesoscale of parenchymatous plant tissue

    NASA Astrophysics Data System (ADS)

    Valous, N. A.; Delgado, A.; Drakakis, K.; Sun, D.-W.

    2014-02-01

    The study of plant tissue parenchyma's intercellular air spaces contributes to the understanding of anatomy and physiology. This is challenging due to difficulty in making direct measurements of the pore space and the complex mosaic of parenchymatous tissue. The architectural complexity of pore space has shown that single geometrical measurements are not sufficient for characterization. The inhomogeneity of distribution depends not only on the percentage content of phase, but also on how the phase fills the space. The lacunarity morphometric, as multiscale measure, provides information about the distribution of gaps that correspond to degree of spatial organization in parenchyma. Additionally, modern theories have suggested strategies, where the focus has shifted from the study of averages and histograms to the study of patterns in data fluctuations. Detrended fluctuation analysis provides information on the correlation properties of the parenchyma at different spatial scales. The aim is to quantify (with the aid of the aforementioned metrics), the mesostructural changes—that occur from one cycle of freezing and thawing—in the void phase of pome fruit parenchymatous tissue, acquired with X-ray microcomputed tomography. Complex systems methods provide numerical indices and detailed insights regarding the freezing-induced modifications upon the arrangement of cells and voids. These structural changes have the potential to lead to physiological disorders. The work can further stimulate interest for the analysis of internal plant tissue structures coupled with other physico-chemical processes or phenomena.

  1. Spatial organization and correlation properties quantify structural changes on mesoscale of parenchymatous plant tissue

    SciTech Connect

    Valous, N. A.; Delgado, A.; Sun, D.-W.; Drakakis, K.

    2014-02-14

    The study of plant tissue parenchyma's intercellular air spaces contributes to the understanding of anatomy and physiology. This is challenging due to difficulty in making direct measurements of the pore space and the complex mosaic of parenchymatous tissue. The architectural complexity of pore space has shown that single geometrical measurements are not sufficient for characterization. The inhomogeneity of distribution depends not only on the percentage content of phase, but also on how the phase fills the space. The lacunarity morphometric, as multiscale measure, provides information about the distribution of gaps that correspond to degree of spatial organization in parenchyma. Additionally, modern theories have suggested strategies, where the focus has shifted from the study of averages and histograms to the study of patterns in data fluctuations. Detrended fluctuation analysis provides information on the correlation properties of the parenchyma at different spatial scales. The aim is to quantify (with the aid of the aforementioned metrics), the mesostructural changes—that occur from one cycle of freezing and thawing—in the void phase of pome fruit parenchymatous tissue, acquired with X-ray microcomputed tomography. Complex systems methods provide numerical indices and detailed insights regarding the freezing-induced modifications upon the arrangement of cells and voids. These structural changes have the potential to lead to physiological disorders. The work can further stimulate interest for the analysis of internal plant tissue structures coupled with other physico-chemical processes or phenomena.

  2. Ecological studies on the revegetation process of surface coal mined areas in North Dakota. 6. Relationship between cover and aboveground biomass. Final report Aug 75-Jun 82

    SciTech Connect

    Schimmelpfennig, D.K.

    1982-06-01

    Assessment of revegetation success on mined lands is a difficult, time consuming task and has been the subject of a number of controversies. Present regulations require that both plant cover and aboveground plant biomass be measured for use in making that assessment. Of these two variables, biomass is the most time consuming to measure and requires destructive sampling, a most undesirable, requirement on fragile, recently revegetated areas. A study was done to evaluate the predictability of aboveground biomass production on revegetated mined sites and adjacent native prairies using plant cover estimates made with the point frame method. A positive, statistically significant correlation was demonstrated between plant cover and aboveground biomass regardless of the community type, species composition, diversity or level of biomass production. However, the latter did have their effects on the relationship and must be accounted for in any predictive equations.

  3. Changes in fatty acid composition in plant tissues expressing a mammalian delta9 desaturase.

    PubMed

    Moon, H; Hazebroek, J; Hildebrand, D F

    2000-05-01

    Plant tissues expressing a mammalian stearoyl-CoA delta9 desaturase were reported to accumulate delta9 hexadecenoic acid (16:1), normally very minor in most plant tissues. The transgenic plants were thoroughly analyzed for alterations of individual lipids in different subcellular sites. Western blot analysis indicated that the animal desaturase was targeted to the microsomes. The delta9 16:1 was incorporated into both the sn-1 and sn-2 positions of all the major membrane lipids tested, indicating that the endoplasmic reticulum acyltransferases do not exclude unsaturated C16 fatty acids from the sn-2 position. In addition to increases in monounsaturated and decreases in saturated fatty acids, accumulation of 16:1 was accompanied by a reduction in 18:3 in all the lipids tested except phosphatidylglycerol, and increases in 18:2 in phospholipids. Total C16 fatty acid content in the galactolipids of the transgenics was significantly higher than that in the control, but those in the phospholipids were unchanged. In transgenics, delta11 18:1 was detected in the sn-1 position of the lipids tested except phosphatidylinositol and phosphatidylserine. Introduction of the animal desaturase, controlled by a seed-specific phaseolin promoter, into soybean somatic embryo resulted in a significant reduction in saturated fatty acids. Such effects were greater in cotyledons than hypocotyl-radicles. This study demonstrated that the animal desaturase can be used to decrease the levels of saturated fatty acids in a crop plant. PMID:10907781

  4. Protocol: a fast and simple in situ PCR method for localising gene expression in plant tissue

    PubMed Central

    2014-01-01

    Background An important step in characterising the function of a gene is identifying the cells in which it is expressed. Traditional methods to determine this include in situ hybridisation, gene promoter-reporter fusions or cell isolation/purification techniques followed by quantitative PCR. These methods, although frequently used, can have limitations including their time-consuming nature, limited specificity, reliance upon well-annotated promoters, high cost, and the need for specialized equipment. In situ PCR is a relatively simple and rapid method that involves the amplification of specific mRNA directly within plant tissue whilst incorporating labelled nucleotides that are subsequently detected by immunohistochemistry. Another notable advantage of this technique is that it can be used on plants that are not easily genetically transformed. Results An optimised workflow for in-tube and on-slide in situ PCR is presented that has been evaluated using multiple plant species and tissue types. The protocol includes optimised methods for: (i) fixing, embedding, and sectioning of plant tissue; (ii) DNase treatment; (iii) in situ RT-PCR with the incorporation of DIG-labelled nucleotides; (iv) signal detection using colourimetric alkaline phosphatase substrates; and (v) mounting and microscopy. We also provide advice on troubleshooting and the limitations of using fluorescence as an alternative detection method. Using our protocol, reliable results can be obtained within two days from harvesting plant material. This method requires limited specialized equipment and can be adopted by any laboratory with a vibratome (vibrating blade microtome), a standard thermocycler, and a microscope. We show that the technique can be used to localise gene expression with cell-specific resolution. Conclusions The in situ PCR method presented here is highly sensitive and specific. It reliably identifies the cellular expression pattern of even highly homologous and low abundance

  5. Cellulase activity screening using pure carboxymethylcellulose: application to soluble cellulolytic samples and to plant tissue prints.

    PubMed

    Johnsen, Hanne R; Krause, Kirsten

    2014-01-01

    Reliable, rapid and inexpensive detection of cellulolytic enzymes that can be used for a wide variety of biological and environmental samples are currently in high demand. Here, a new cellulase detection protocol is described that circumvents problems observed with popular agar-based methods by exploiting the ability of carboxymethylcellulose (CMC) to form gel-like surfaces on its own. These pure CMC-layers are sensitive to cellulolytic degradation and stainable by Gram's iodine without showing unwelcome reactions with other enzymes. The staining intensity negatively correlates with the enzyme activity and can be used for quantification. Cellulase activities are not obstructed by high sugar contents (e.g., in plant material) which limit the applicability of other quantification methods, making our new method particularly attractive for screening of plant extracts. A useful variant of this new method is its applicability to plant tissue prints for spatial mapping of the cellulolytic activity in a zymogram-like fashion. PMID:24413752

  6. Herbivory reduces plant interactions with above- and belowground antagonists and mutualists.

    PubMed

    Barber, Nicholas A; Adler, Lynn S; Theis, Nina; Hazzard, Ruth V; Kiers, E Toby

    2012-07-01

    Herbivores affect plants through direct effects, such as tissue damage, and through indirect effects that alter species interactions. Interactions may be positive or negative, so indirect effects have the potential to enhance or lessen the net impacts of herbivores. Despite the ubiquity of these interactions, the indirect pathways are considerably less understood than the direct effects of herbivores, and multiple indirect pathways are rarely studied simultaneously. We placed herbivore effects in a comprehensive community context by studying how herbivory influences plant interactions with antagonists and mutualists both aboveground and belowground. We manipulated early-season aboveground herbivore damage to Cucumis sativus (cucumber, Cucurbitaceae) and measured interactions with subsequent aboveground herbivores, root-feeding herbivores, pollinators, and arbuscular mycorrhizal fungi (AMF). We quantified plant growth and reproduction and used an enhanced pollination treatment to determine if plants were pollen limited. Increased herbivory reduced interactions with both antagonists and mutualists. Plants with high levels of early herbivory were significantly less likely to suffer leaf damage later in the summer and tended to be less attacked by root herbivores. Herbivory also reduced pollinator visitation, likely due to fewer and smaller flowers, and reduced AMF colonization. The net effect of herbivory on plant growth and reproduction was strongly negative, but lower fruit and seed production were not due to reduced pollinator visits, because reproduction was not pollen limited. Although herbivores influenced interactions between plants and other organisms, these effects appear to be weaker than the direct negative effects of early-season tissue loss. PMID:22919903

  7. Aboveground-belowground biodiversity linkages differ in early and late successional temperate forests

    PubMed Central

    Li, Hui; Wang, Xugao; Liang, Chao; Hao, Zhanqing; Zhou, Lisha; Ma, Sam; Li, Xiaobin; Yang, Shan; Yao, Fei; Jiang, Yong

    2015-01-01

    Understanding ecological linkages between above- and below-ground biota is critical for deepening our knowledge on the maintenance and stability of ecosystem processes. Nevertheless, direct comparisons of plant-microbe diversity at the community level remain scarce due to the knowledge gap between microbial ecology and plant ecology. We compared the α- and β- diversities of plant and soil bacterial communities in two temperate forests that represented early and late successional stages. We documented different patterns of aboveground-belowground diversity relationships in these forests. We observed no linkage between plant and bacterial α-diversity in the early successional forest, and even a negative correlation in the late successional forest, indicating that high bacterial α-diversity is not always linked to high plant α-diversity. Beta-diversity coupling was only found at the late successional stage, while in the early successional forest, the bacterial β-diversity was closely correlated with soil property distances. Additionally, we showed that the dominant competitive tree species in the late successional forest may play key roles in driving forest succession by shaping the soil bacterial community in the early successional stage. This study sheds new light on the potential aboveground-belowground linkage in natural ecosystems, which may help us understand the mechanisms that drive ecosystem succession. PMID:26184121

  8. Aboveground-belowground biodiversity linkages differ in early and late successional temperate forests.

    PubMed

    Li, Hui; Wang, Xugao; Liang, Chao; Hao, Zhanqing; Zhou, Lisha; Ma, Sam; Li, Xiaobin; Yang, Shan; Yao, Fei; Jiang, Yong

    2015-01-01

    Understanding ecological linkages between above- and below-ground biota is critical for deepening our knowledge on the maintenance and stability of ecosystem processes. Nevertheless, direct comparisons of plant-microbe diversity at the community level remain scarce due to the knowledge gap between microbial ecology and plant ecology. We compared the α- and β- diversities of plant and soil bacterial communities in two temperate forests that represented early and late successional stages. We documented different patterns of aboveground-belowground diversity relationships in these forests. We observed no linkage between plant and bacterial α-diversity in the early successional forest, and even a negative correlation in the late successional forest, indicating that high bacterial α-diversity is not always linked to high plant α-diversity. Beta-diversity coupling was only found at the late successional stage, while in the early successional forest, the bacterial β-diversity was closely correlated with soil property distances. Additionally, we showed that the dominant competitive tree species in the late successional forest may play key roles in driving forest succession by shaping the soil bacterial community in the early successional stage. This study sheds new light on the potential aboveground-belowground linkage in natural ecosystems, which may help us understand the mechanisms that drive ecosystem succession. PMID:26184121

  9. Aboveground-belowground biodiversity linkages differ in early and late successional temperate forests

    NASA Astrophysics Data System (ADS)

    Li, Hui; Wang, Xugao; Liang, Chao; Hao, Zhanqing; Zhou, Lisha; Ma, Sam; Li, Xiaobin; Yang, Shan; Yao, Fei; Jiang, Yong

    2015-07-01

    Understanding ecological linkages between above- and below-ground biota is critical for deepening our knowledge on the maintenance and stability of ecosystem processes. Nevertheless, direct comparisons of plant-microbe diversity at the community level remain scarce due to the knowledge gap between microbial ecology and plant ecology. We compared the α- and β- diversities of plant and soil bacterial communities in two temperate forests that represented early and late successional stages. We documented different patterns of aboveground-belowground diversity relationships in these forests. We observed no linkage between plant and bacterial α-diversity in the early successional forest, and even a negative correlation in the late successional forest, indicating that high bacterial α-diversity is not always linked to high plant α-diversity. Beta-diversity coupling was only found at the late successional stage, while in the early successional forest, the bacterial β-diversity was closely correlated with soil property distances. Additionally, we showed that the dominant competitive tree species in the late successional forest may play key roles in driving forest succession by shaping the soil bacterial community in the early successional stage. This study sheds new light on the potential aboveground-belowground linkage in natural ecosystems, which may help us understand the mechanisms that drive ecosystem succession.

  10. Topographically mediated controls on aboveground biomass across a mediterranean-type landscape

    NASA Astrophysics Data System (ADS)

    Dahlin, K.; Asner, G. P.; Field, C. B.

    2009-12-01

    Aboveground biomass accumulation is a useful metric for evaluating habitat restoration and ecosystem services projects, in addition to being a robust measure of carbon sequestration. However, at the landscape scale non-anthropogenic controls on biomass accumulation are poorly understood. In this study we combined field measurements, high resolution data from the NASA JPL Airborne Visible/Infrared Imaging Spectrometer (AVIRIS), and the Carnegie Airborne Observatory (CAO) airborne light detection and ranging (lidar) system to create a comprehensive map of aboveground biomass across a patchy mediterranean-type landscape (Jasper Ridge Biological Preserve, Stanford, CA). Candidate explanatory variables (e.g. slope, elevation, incident solar radiation) were developed using a geologic map and a digital elevation model derived from the lidar data. Finally, candidate variables were tested, and a model was produced to predict aboveground biomass from environmental data. Though many of the explanatory variables have only indirect effects on plant growth, the model permits inferences to be made about the relative importance of light, water, temperature, and edaphic characteristics on carbon accumulation in mediterranean-type systems.

  11. Aboveground vertebrate and invertebrate herbivore impact on net N mineralization in subalpine grasslands.

    PubMed

    Risch, Anita C; Schotz, Martin; Vandegehuchte, Martijn L; Van Der Putten, Wim H; Duyts, Henk; Raschein, Ursina; Gwiazdowicz, Dariusz J; Busse, Matt D; Page-dumroese, Deborah S; Zimmermann, Stephan

    2015-12-01

    Aboveground herbivores have strong effects on grassland nitrogen (N) cycling. They can accelerate or slow down soil net N mineralization depending on ecosystem productivity and grazing intensity. Yet, most studies only consider either ungulates or invertebrate herbivores, but not the combined effect of several functionally different vertebrate and invertebrate herbivore species or guilds. We assessed how a diverse herbivore community affects net N mineralization in subalpine grasslands. By using size-selective fences, we progressively excluded large, medium, and small mammals, as well as invertebrates from two vegetation types, and assessed how the exclosure types (ET) affected net N mineralization. The two vegetation types differed in long-term management (centuries), forage quality, and grazing history and intensity. To gain a more mechanistic understanding of how herbivores affect net N mineralization, we linked mineralization to soil abiotic (temperature; moisture; NO3-, NH4+, and total inorganic N concentrations/pools; C, N, P concentrations; pH; bulk density), soil biotic (microbial biomass; abundance of collembolans, mites, and nematodes) and plant (shoot and root biomass; consumption; plant C, N, and fiber content; plant N pool) properties. Net N mineralization differed between ET, but not between vegetation types. Thus, short-term changes in herbivore community composition and, therefore, in grazing intensity had a stronger effect on net N mineralization than long-term management and grazing history. We found highest N mineralization values when only invertebrates were present, suggesting that mammals had a negative effect on net N mineralization. Of the variables included in our analyses, only mite abundance and aboveground plant biomass explained variation in net N mineralization among ET. Abundances of both mites and leaf-sucking invertebrates were positively correlated with aboveground plant biomass, and biomass increased with progressive exclusion

  12. Application of GC-MS for the detection of lipophilic compounds in diverse plant tissues

    PubMed Central

    Lytovchenko, Anna; Beleggia, Romina; Schauer, Nicolas; Isaacson, Tal; Leuendorf, Jan E; Hellmann, Hanjo; Rose, Jocelyn KC; Fernie, Alisdair R

    2009-01-01

    Background The concept of metabolite profiling has been around for decades and technical innovations are now enabling it to be carried out on a large scale with respect to the number of both metabolites measured and experiments carried out. However, studies are generally confined to polar compounds alone. Here we describe a simple method for lipophilic compounds analysis in various plant tissues. Results We choose the same preparative and instrumental platform for lipophilic profiling as that we routinely use for polar metabolites measurements. The method was validated in terms of linearity, carryover, reproducibility and recovery rates, as well as using various plant tissues. As a first case study we present metabolic profiling of Arabidopsis root and shoot tissue of wild type (C24) and mutant (rsr4-1) plants deficient on vitamin B6. We found significant alterations in lipid constituent contents, especially in the roots, which were characterised by dramatic increases in several fatty acids, thus providing further hint for the role of pyridoxine in oxidative stress and lipid peroxidation. The second example is the lipophilic profiling of red and green tomato fruit cuticles of wild type (Alisa Craig) and the DFD (delayed fruit deterioration) mutant, which we compared and contrasted with the more focused wax analysis of these plants reported before. Conclusion We can rapidly and reliably detect and quantify over 40 lipophilic metabolites including fatty acids, fatty alcohols, alkanes, sterols and tocopherols. The method presented here affords a simple and rapid, yet robust complement to previously validated methods of polar metabolite profiling by gas-chromatography mass-spectrometry. PMID:19393072

  13. Complete genome sequence of the plant growth-promoting endophyte Burkholderia phytofirmans strain PsJN.

    PubMed

    Weilharter, Alexandra; Mitter, Birgit; Shin, Maria V; Chain, Patrick S G; Nowak, Jerzy; Sessitsch, Angela

    2011-07-01

    Burkholderia phytofirmans PsJN(T) is able to efficiently colonize the rhizosphere, root, and above-ground plant tissues of a wide variety of genetically unrelated plants, such as potatoes, canola, maize, and grapevines. Strain PsJN shows strong plant growth-promoting effects and was reported to enhance plant vigor and resistance to biotic and abiotic stresses. Here, we report the genome sequence of this strain, which indicates the presence of multiple traits relevant for endophytic colonization and plant growth promotion. PMID:21551308

  14. In situ detection of salicylic acid binding sites in plant tissues.

    PubMed

    Liu, Jing-Wen; Deng, Da-Yi; Yu, Ying; Liu, Fang-Fei; Lin, Bi-Xia; Cao, Yu-Juan; Hu, Xiao-Gang; Wu, Jian-Zhong

    2015-02-01

    The determination of hormone-binding sites in plants is essential in understanding the mechanisms behind hormone function. Salicylic acid (SA) is an important plant hormone that regulates responses to biotic and abiotic stresses. In order to label SA-binding sites in plant tissues, a quantum dots (QDs) probe functionalized with a SA moiety was successfully synthesized by coupling CdSe QDs capped with 3-mercaptopropionic acid (MPA) to 4-amino-2-hydroxybenzoic acid (PAS), using 1-ethyl-3-(3-dimethyllaminopropyl) carbodiimide (EDC) as the coupling agent. The probe was then characterized by dynamic light scattering and transmission electron microscopy, as well as UV/vis and fluorescence spectrophotometry. The results confirmed the successful conjugation of PAS to CdSe QDs and revealed that the conjugates maintained the properties of the original QDs, with small core diameters and adequate dispersal in solution. The PAS-CdSe QDs were used to detect SA-binding sites in mung bean and Arabidopsis thaliana seedlings in vitro and in vivo. The PAS-CdSe QDs were effectively transported into plant tissues and specifically bound to SA receptors in vivo. In addition, the effects of the PAS-CdSe QDs on cytosolic Ca(2+) levels in the tips of A. thaliana seedlings were investigated. Both SA and PAS-CdSe QDs had similar effects on the trend in cytosolic-free Ca(2+) concentrations, suggesting that the PAS-CdSe QDs maintained the bioactivity of SA. To summarize, PAS-CdSe QDs have high potential as a fluorescent probe for the in vitro/in vivo labeling and imaging of SA receptors in plants. PMID:24833131

  15. Biological Warfare of the Spiny Plant Introducing Pathogenic Microorganisms into Herbivore's Tissues.

    PubMed

    Halpern, Malka; Waissler, Avivit; Dror, Adi; Lev-Yadun, Simcha

    2011-01-01

    Recently, it has been proposed that plants which have spines, thorns, and prickles use pathogenic aerobic and anaerobic bacteria, as well as pathogenic fungi, for defense against herbivores, especially vertebrates. Their sharp defensive appendages may inject various pathogenic agents into the body of the herbivores by piercing the outer defensive layer of the skin in a type of biological warfare. Here, we review data regarding the various bacterial taxa found on spines, as well as the medical literature regarding infections by bacteria and fungi related to spine injuries. We also present new evidence that, concerning the microbial flora, spines belonging to the palm tree Washingtonia filifera are probably a different habitat than the nondefensive green photosynthetic leaf surfaces. In addition, many plant species have microscopic internal and external spines (raphids and silica needles) which can also wound large herbivores as well as insects and other small invertebrate herbivores that usually attack in between large spines, prickles, and thorns. The large spines and sharp microscopic structures may inject not only the microorganisms that inhabit them into the herbivore's tissues, but also those preexisting on the skin surface or inside the digestive system of the herbivores and on the surface of nonspiny plant parts. A majority of the spiny plants visually advertise their spiny nature, a characteristic known as aposematism (warning coloration). The pathogenic microorganisms may sometimes be much more dangerous than the physical wounds inflicted by the spines. In accordance, we suggest that the possible cooperation or even just the random association of spines with pathogenic microorganisms contributed to the evolution of aposematism in spiny plants and animals. The role of these sharp defensive structures in inserting pathogenic viruses into the tissues of herbivores was never studied systematically and deserves special attention. PMID:21459195

  16. Application of the chloramphenicol acetyltransferase (CAT) diffusion assay to transgenic plant tissues.

    PubMed

    Peach, C; Velten, J

    1992-02-01

    Chloramphenicol acetyltransferase (CAT) activity was quantified in crude extracts from tobacco callus tissues using a modification of a previously reported diffusion assay. We describe here the alterations necessary in applying this rapid and simple assay procedure to plant materials. Due to the high concentration of nonspecific oxidases present in most plant tissues, some type of protective agent is required to maintain enzyme activity. We have tested beta-mercaptoethanol, cysteine, dithiothreitol, ascorbic acid and polyvinyl pyrrolidone as protective agents within the initial extraction buffer. We also investigated the effect of heat (60 degrees C, 10 min) and 5 mM EDTA on CAT activity. The highest CAT activity was obtained using 5 mM cysteine plus 5 mM EDTA in 40 mM Tris-HCl (pH 7.8) as the initial extraction buffer followed by a heat treatment. Using this buffer, CAT activity was stable on ice for more than two hours. In our hands, total acetyl-coenzyme A concentration within the assay mixture was found to be saturating at 250 microM and the Km determined to be 100 microM. Assays performed using the same crude plant extract indicate that 1) duplicate assays show less than 1.5% variation in activities and 2) CAT activity increases linearly with respect to volume of extract used. PMID:1616705

  17. Cellular Force Microscopy for in Vivo Measurements of Plant Tissue Mechanics1[W][OA

    PubMed Central

    Routier-Kierzkowska, Anne-Lise; Weber, Alain; Kochova, Petra; Felekis, Dimitris; Nelson, Bradley J.; Kuhlemeier, Cris; Smith, Richard S.

    2012-01-01

    Although growth and morphogenesis are controlled by genetics, physical shape change in plant tissue results from a balance between cell wall loosening and intracellular pressure. Despite recent work demonstrating a role for mechanical signals in morphogenesis, precise measurement of mechanical properties at the individual cell level remains a technical challenge. To address this challenge, we have developed cellular force microscopy (CFM), which combines the versatility of classical microindentation techniques with the high automation and resolution approaching that of atomic force microscopy. CFM’s large range of forces provides the possibility to map the apparent stiffness of both plasmolyzed and turgid tissue as well as to perform micropuncture of cells using very high stresses. CFM experiments reveal that, within a tissue, local stiffness measurements can vary with the level of turgor pressure in an unexpected way. Altogether, our results highlight the importance of detailed physically based simulations for the interpretation of microindentation results. CFM’s ability to be used both to assess and manipulate tissue mechanics makes it a method of choice to unravel the feedbacks between mechanics, genetics, and morphogenesis. PMID:22353572

  18. Increased tumor homing and tissue penetration of the filamentous plant viral nanoparticle Potato virus X

    PubMed Central

    Shukla, Sourabh; Ablack, Amber L.; Wen, Amy M.; Lee, Karin L.; Lewis, John D.; Steinmetz, Nicole F.

    2012-01-01

    Nanomaterials with elongated architectures have been shown to possess differential tumor homing properties compared to their spherical counterparts. Here, we investigate whether this phenomenon is mirrored by plant viral nanoparticles that are filamentous (Potato virus X) or spherical (Cowpea mosaic virus). Our studies demonstrate that Potato virus X (PVX) and Cowpea mosaic virus (CPMV) show distinct biodistribution profiles and differ in their tumor homing and penetration efficiency. Analogous to what is seen with inorganic nanomaterials, PVX shows enhanced tumor homing and tissue penetration. Human tumor xenografts exhibit higher uptake of PEGylated filamentous PVX compared to CPMV, particularly in the core of the tumor. This is supported by immunohistochemical analysis of the tumor sections, which indicates greater penetration and accumulation of PVX within the tumor tissues. The enhanced tumor homing and retention properties of PVX along with its higher payload carrying capacity makes it a potentially superior platform for applications in cancer drug delivery and imaging applications. PMID:22731633

  19. MODIS Based Estimation of Forest Aboveground Biomass in China

    PubMed Central

    Sun, Yan; Wang, Tao; Zeng, Zhenzhong; Piao, Shilong

    2015-01-01

    Accurate estimation of forest biomass C stock is essential to understand carbon cycles. However, current estimates of Chinese forest biomass are mostly based on inventory-based timber volumes and empirical conversion factors at the provincial scale, which could introduce large uncertainties in forest biomass estimation. Here we provide a data-driven estimate of Chinese forest aboveground biomass from 2001 to 2013 at a spatial resolution of 1 km by integrating a recently reviewed plot-level ground-measured forest aboveground biomass database with geospatial information from 1-km Moderate-Resolution Imaging Spectroradiometer (MODIS) dataset in a machine learning algorithm (the model tree ensemble, MTE). We show that Chinese forest aboveground biomass is 8.56 Pg C, which is mainly contributed by evergreen needle-leaf forests and deciduous broadleaf forests. The mean forest aboveground biomass density is 56.1 Mg C ha−1, with high values observed in temperate humid regions. The responses of forest aboveground biomass density to mean annual temperature are closely tied to water conditions; that is, negative responses dominate regions with mean annual precipitation less than 1300 mm y−1 and positive responses prevail in regions with mean annual precipitation higher than 2800 mm y−1. During the 2000s, the forests in China sequestered C by 61.9 Tg C y−1, and this C sink is mainly distributed in north China and may be attributed to warming climate, rising CO2 concentration, N deposition, and growth of young forests. PMID:26115195

  20. MODIS Based Estimation of Forest Aboveground Biomass in China.

    PubMed

    Yin, Guodong; Zhang, Yuan; Sun, Yan; Wang, Tao; Zeng, Zhenzhong; Piao, Shilong

    2015-01-01

    Accurate estimation of forest biomass C stock is essential to understand carbon cycles. However, current estimates of Chinese forest biomass are mostly based on inventory-based timber volumes and empirical conversion factors at the provincial scale, which could introduce large uncertainties in forest biomass estimation. Here we provide a data-driven estimate of Chinese forest aboveground biomass from 2001 to 2013 at a spatial resolution of 1 km by integrating a recently reviewed plot-level ground-measured forest aboveground biomass database with geospatial information from 1-km Moderate-Resolution Imaging Spectroradiometer (MODIS) dataset in a machine learning algorithm (the model tree ensemble, MTE). We show that Chinese forest aboveground biomass is 8.56 Pg C, which is mainly contributed by evergreen needle-leaf forests and deciduous broadleaf forests. The mean forest aboveground biomass density is 56.1 Mg C ha-1, with high values observed in temperate humid regions. The responses of forest aboveground biomass density to mean annual temperature are closely tied to water conditions; that is, negative responses dominate regions with mean annual precipitation less than 1300 mm y-1 and positive responses prevail in regions with mean annual precipitation higher than 2800 mm y-1. During the 2000s, the forests in China sequestered C by 61.9 Tg C y-1, and this C sink is mainly distributed in north China and may be attributed to warming climate, rising CO2 concentration, N deposition, and growth of young forests. PMID:26115195

  1. Plant Tissues in 3D via X-Ray Tomography: Simple Contrasting Methods Allow High Resolution Imaging

    PubMed Central

    Staedler, Yannick M.; Masson, David; Schönenberger, Jürg

    2013-01-01

    Computed tomography remains strongly underused in plant sciences despite its high potential in delivering detailed 3D phenotypical information because of the low X-ray absorption of most plant tissues. Existing protocols to study soft tissues display poor performance, especially when compared to those used on animals. More efficient protocols to study plant material are therefore needed. Flowers of Arabidopsis thaliana and Marcgravia caudata were immersed in a selection of contrasting agents used to treat samples for transmission electron microscopy. Grayscale values for floral tissues and background were measured as a function of time. Contrast was quantified via a contrast index. The thick buds of Marcgravia were scanned to determine which contrasting agents best penetrate thick tissues. The highest contrast increase with cytoplasm-rich tissues was obtained with phosphotungstate, whereas osmium tetroxide and bismuth tatrate displayed the highest contrast increase with vacuolated tissues. Phosphotungstate also displayed the best sample penetration. Furthermore, infiltration with phosphotungstate allowed imaging of all plants parts at a high resolution of 3 µm, which approaches the maximum resolution of our equipment: 1.5 µm. The high affinity of phosphotungstate for vasculature, cytoplasm-rich tissue, and pollen causes these tissues to absorb more X-rays than the surrounding tissues, which, in turn, makes these tissues appear brighter on the scan data. Tissues with different brightness can then be virtually dissected from each other by selecting the bracket of grayscale to be visualized. Promising directions for the future include in silico phenotyping and developmental studies of plant inner parts (e.g., ovules, vasculature, pollen, and cell nuclei) via virtual dissection as well as correlations of quantitative phenotypes with omics datasets. Therefore, this work represents a crucial improvement of previous methods, allowing new directions of research to be

  2. Plant tissues in 3D via X-ray tomography: simple contrasting methods allow high resolution imaging.

    PubMed

    Staedler, Yannick M; Masson, David; Schönenberger, Jürg

    2013-01-01

    Computed tomography remains strongly underused in plant sciences despite its high potential in delivering detailed 3D phenotypical information because of the low X-ray absorption of most plant tissues. Existing protocols to study soft tissues display poor performance, especially when compared to those used on animals. More efficient protocols to study plant material are therefore needed. Flowers of Arabidopsis thaliana and Marcgravia caudata were immersed in a selection of contrasting agents used to treat samples for transmission electron microscopy. Grayscale values for floral tissues and background were measured as a function of time. Contrast was quantified via a contrast index. The thick buds of Marcgravia were scanned to determine which contrasting agents best penetrate thick tissues. The highest contrast increase with cytoplasm-rich tissues was obtained with phosphotungstate, whereas osmium tetroxide and bismuth tatrate displayed the highest contrast increase with vacuolated tissues. Phosphotungstate also displayed the best sample penetration. Furthermore, infiltration with phosphotungstate allowed imaging of all plants parts at a high resolution of 3 µm, which approaches the maximum resolution of our equipment: 1.5 µm. The high affinity of phosphotungstate for vasculature, cytoplasm-rich tissue, and pollen causes these tissues to absorb more X-rays than the surrounding tissues, which, in turn, makes these tissues appear brighter on the scan data. Tissues with different brightness can then be virtually dissected from each other by selecting the bracket of grayscale to be visualized. Promising directions for the future include in silico phenotyping and developmental studies of plant inner parts (e.g., ovules, vasculature, pollen, and cell nuclei) via virtual dissection as well as correlations of quantitative phenotypes with omics datasets. Therefore, this work represents a crucial improvement of previous methods, allowing new directions of research to be

  3. Factors Affecting the Extraction of Intact Ribonucleic Acid from Plant Tissues Containing Interfering Phenolic Compounds

    PubMed Central

    Newbury, H. John; Possingham, John V.

    1977-01-01

    Using conventional methods it is impossible to extract RNA as uncomplexed intact molecules from the leaves of grapevines (Vitis vinifera L.) and from a number of woody perennial species that contain high levels of reactive phenolic compounds. A procedure involving the use of high concentrations of the chaotropic agent sodium perchlorate prevents the binding of phenolic compounds to RNA during extraction. Analyses of the phenolics present in plant tissues used in these experiments indicate that there is a poor correlation between the total phenolic content and the complexing of RNA. However, qualitative analyses suggest that proanthocyanidins are involved in the tanning of RNA during conventional extractions. PMID:16660134

  4. Development of Plant Gene Vectors for Tissue-Specific Expression Using GFP as a Reporter Gene

    NASA Technical Reports Server (NTRS)

    Jackson, Jacquelyn; Egnin, Marceline; Xue, Qi-Han; Prakash, C. S.

    1997-01-01

    Reporter genes are widely employed in plant molecular biology research to analyze gene expression and to identify promoters. Gus (UidA) is currently the most popular reporter gene but its detection requires a destructive assay. The use of jellyfish green fluorescent protein (GFP) gene from Aequorea Victoria holds promise for noninvasive detection of in vivo gene expression. To study how various plant promoters are expressed in sweet potato (Ipomoea batatas), we are transcriptionally fusing the intron-modified (mGFP) or synthetic (modified for codon-usage) GFP coding regions to these promoters: double cauliflower mosaic virus 35S (CaMV 35S) with AMV translational enhancer, ubiquitin7-intron-ubiquitin coding region (ubi7-intron-UQ) and sporaminA. A few of these vectors have been constructed and introduced into E. coli DH5a and Agrobacterium tumefaciens EHA105. Transient expression studies are underway using protoplast-electroporation and particle bombardment of leaf tissues.

  5. Picosecond time-gated microscopy of UV-damaged plant tissue

    NASA Astrophysics Data System (ADS)

    Rehman, S.; Lukins, Philip B.

    2002-04-01

    We demonstrate that picosecond time-gated fluorescence microscopy can be used to monitor subtle changes in the kinetics and spatial distribution of perturbations to the molecular and cellular structure of plant tissue caused by ultraviolet radiation. Single-molecule experiments on Photosystem II and chloroplast preparations give picosecond fluorescence decay kinetics that are similar to those obtained previously on bulk samples. For green plant leaves, localized and well-defined cellular structure is seen for normal material whereas relatively diffuse and non-specific features are seen after UV-irradiation indicating significant UV-induced rupture of the cellular structure. The changes in the chlorophyll fluorescence decay kinetics indicate uncoupling of chlorophyll molecules in the light-harvesting system leading to inhibition of energy reorganization and transfer in the antennae and subsequent exciton transfer to the reaction centers.

  6. Lasting effects of climate disturbance on perennial grassland above-ground biomass production under two cutting frequencies.

    PubMed

    Zwicke, Marine; Alessio, Giorgio A; Thiery, Lionel; Falcimagne, Robert; Baumont, René; Rossignol, Nicolas; Soussana, Jean-François; Picon-Cochard, Catherine

    2013-11-01

    Climate extremes can ultimately reshape grassland services such as forage production and change plant functional type composition. This 3-year field research studied resistance to dehydration and recovery after rehydration of plant community and plant functional types in an upland perennial grassland subjected to climate and cutting frequency (Cut+, Cut-) disturbances by measuring green tissue percentage and above-ground biomass production (ANPP). In year 1, a climate disturbance gradient was applied by co-manipulating temperature and precipitation. Four treatments were considered: control and warming-drought climatic treatment, with or without extreme summer event. In year 2, control and warming-drought treatments were maintained without extreme. In year 3, all treatments received ambient climatic conditions. We found that the grassland community was very sensitive to dehydration during the summer extreme: aerial senescence reached 80% when cumulated climatic water balance fell to -156 mm and biomass declined by 78% at the end of summer. In autumn, canopy greenness and biomass totally recovered in control but not in the warming-drought treatment. However ANPP decreased under both climatic treatments, but the effect was stronger on Cut+ (-24%) than Cut- (-15%). This decline was not compensated by the presence of three functional types because they were negatively affected by the climatic treatments, suggesting an absence of buffering effect on grassland production. In the following 2 years, lasting effects of climate disturbance on ANPP were observable. The unexpected stressful conditions of year 3 induced a decline in grassland production in the Cut+ control treatment. The fact that this treatment cumulated higher (45%) N export over the 3 years suggests that N plays a key role in ANPP stability. As ANPP in this mesic perennial grassland did not show engineering resilience, long-term experimental manipulation is needed. Infrequent mowing appears more

  7. Electrophysiological model of intact and processed plant tissues: cell disintegration criteria.

    PubMed

    Angersbach, A; Heinz, V; Knorr, D

    1999-01-01

    Frequency versus conductivity relationships of food cell system, based on impedance measurements as characterized by polarization effects of the Maxwell-Wagner type at intact membrane interfaces, are presented. The electrical properties of a biological membrane (represented as a resistor and capacitor) are responsible for the dependence of the total conductivity of the cell system on the alternating current frequency. Based on an equivalent circuit model of a single plant cell, the electrical conductivity spectrum of the cell system in intact plant tissue (potato, carrot, banana, and apple) was determined in a frequency range between 3 kHz and 50 MHz. The electrical properties of a cell system with different ratios of intact/ruptured cells could also be predicted on the basis of a description of a cell system consisting of elementary layers with regularly distributed intact and ruptured cells as well as of extracellular compartments. This simple determination of the degree of cell permeabilization (cell disintegration index, p(o)) is based upon electric conductivity changes in the cell sample. For accurate calculations of p(o), the sample conductivities before and after treatment, obtained at low- (f(l)) and high-frequency (f(h)) ranges of the so-called beta-dispersion, were used. In this study with plant cell systems, characteristic conductivities used were measured at frequencies f(l) = 3 kHz and f(h) = 12.5 MHz. The disintegration index was used to analyze the degree of cell disruption after different treatments (such as mechanical disruption, heating, freeze-thaw cycles, application of electric field pulses, and enzymatic treatment) of the plant tissues. PMID:10441367

  8. Ecosystem engineering and manipulation of host plant tissues by the insect borer Oncideres albomarginata chamela.

    PubMed

    Calderón-Cortés, Nancy; Uribe-Mú, Claudia A; Martínez-Méndez, A Karen; Escalera-Vázquez, Luis H; Cristobal-Pérez, E Jacob; García-Oliva, Felipe; Quesada, Mauricio

    2016-01-01

    Ecosystem engineering by insect herbivores occurs as the result of structural modification of plants manipulated by insects. However, only few studies have evaluated the effect of these modifications on the plant responses induced by stem-borers that act as ecosystem engineers. In this study, we evaluated the responses induced by the herbivory of the twig-girdler beetle Oncideres albomarginata chamela (Cerambycidae: Lamiinae) on its host plant Spondias purpurea (Anacardiaceae), and its relationship with the ecosystem engineering process carried out by this stem-borer. Our results demonstrated that O. albomarginata chamela branch removal induced the development of lateral branches increasing the resources needed for the development of future insect generations, of its own offspring and of many other insect species. Detached branches represent habitats with high content of nitrogen and phosphorous, which eventually can be incorporated into the ecosystem, increasing nutrient cycling efficiency. Consequently, branch removal and the subsequent plant tissue regeneration induced by O. albomarginata chamela represent key mechanisms underlying the ecosystem engineering process carried out by this stem-borer, which enhances arthropod diversity in the ecosystem. PMID:26654885

  9. Two micro-scale protocols for the isolation of DNA from polysaccharide-rich plant tissue.

    PubMed

    Shepherd, Lara D; McLay, Todd G B

    2011-03-01

    The high polysaccharide content of some plant species hinders the successful isolation of their DNA. As an alternative to the macro-extraction methods previously published for polysaccharide-rich plants, we present two techniques (STE/CTAB and HEPES/CTAB), which are performed in microcentrifuge tubes. These protocols are suitable for small amounts of silica gel-preserved plant tissue such as are commonly available from endangered plants. The critical step to remove polysaccharides was performing initial washes in either STE (0.25 M sucrose, 0.03 M Tris, 0.05 M EDTA) or HEPES (2% β-mercaptoethanol, 0.2% PVP, 0.1 M HEPES, pH 8.0) buffer. Precipitating the DNA at room temperature with isopropanol also aided in decreasing polysaccharide co-precipitation. Of the two protocols we present the STE/CTAB method has the advantages of being more cost-effective and avoiding the use of the hazardous chemical β-mercaptoethanol. PMID:20927638

  10. Biomanufacturing of protective antibodies and other therapeutics in edible plant tissues for oral applications.

    PubMed

    Juarez, Paloma; Virdi, Vikram; Depicker, Ann; Orzaez, Diego

    2016-09-01

    Although plant expression systems used for production of therapeutic proteins have the advantage of being scalable at a low price, the downstream processing necessary to obtain pure therapeutic molecules is as expensive as for the traditional Chinese hamster ovary (CHO) platforms. However, when edible plant tissues (EPTs) are used, there is no need for exhaustive purification, because they can be delivered orally as partially purified formulations that are safe for consumption. This economic benefit is especially interesting when high doses of recombinant proteins are required throughout the treatment/prophylaxis period, as is the case for antibodies used for oral passive immunization (OPI). The secretory IgA (SIgA) antibodies, which are highly abundant in the digestive tract and mucosal secretions, and thus the first choice for OPI, have only been successfully produced in plant expression systems. Here, we cover most of the up-to-date examples of EPT-produced pharmaceuticals, including two examples of SIgA aimed at oral delivery. We describe the benefits and drawbacks of delivering partially purified formulations and discuss a number of practical considerations and criteria to take into account when using plant expression systems, such as subcellular targeting, protein degradation, glycosylation patterns and downstream strategies, all crucial for improved yield, high quality and low cost of the final product. PMID:26873071

  11. Expression of a ricin toxin B subunit: insulin fusion protein in edible plant tissues.

    PubMed

    Carter, James E; Odumosu, Oludare; Langridge, William H R

    2010-02-01

    Onset of juvenile Type 1 diabetes (T1D) occurs when autoreactive lymphocytes progressively destroy the insulin-producing beta-cells in the pancreatic Islets of Langerhans. The increasing lack of insulin and subsequent onset of hyperglycemia results in increased damage to nerves, blood vessels, and tissues leading to the development of a host of severe disease symptoms resulting in premature morbidity and mortality. To enhance restoration of normoglycemia and immunological homeostasis generated by lymphocytes that mediate the suppression of autoimmunity, the non-toxic B chain of the plant AB enterotoxin ricin (RTB), a castor bean lectin binding a variety of epidermal cell receptors, was genetically linked to the coding region of the proinsulin gene (INS) and expressed as a fusion protein (INS-RTB) in transformed potato plants. This study is the first documented example of a plant enterotoxin B subunit linked to an autoantigen and expressed in transgenic plants for enhanced immunological suppression of T1D autoimmunity. PMID:19898971

  12. Developing a generalized allometric equation for aboveground biomass estimation

    NASA Astrophysics Data System (ADS)

    Xu, Q.; Balamuta, J. J.; Greenberg, J. A.; Li, B.; Man, A.; Xu, Z.

    2015-12-01

    A key potential uncertainty in estimating carbon stocks across multiple scales stems from the use of empirically calibrated allometric equations, which estimate aboveground biomass (AGB) from plant characteristics such as diameter at breast height (DBH) and/or height (H). The equations themselves contain significant and, at times, poorly characterized errors. Species-specific equations may be missing. Plant responses to their local biophysical environment may lead to spatially varying allometric relationships. The structural predictor may be difficult or impossible to measure accurately, particularly when derived from remote sensing data. All of these issues may lead to significant and spatially varying uncertainties in the estimation of AGB that are unexplored in the literature. We sought to quantify the errors in predicting AGB at the tree and plot level for vegetation plots in California. To accomplish this, we derived a generalized allometric equation (GAE) which we used to model the AGB on a full set of tree information such as DBH, H, taxonomy, and biophysical environment. The GAE was derived using published allometric equations in the GlobAllomeTree database. The equations were sparse in details about the error since authors provide the coefficient of determination (R2) and the sample size. A more realistic simulation of tree AGB should also contain the noise that was not captured by the allometric equation. We derived an empirically corrected variance estimate for the amount of noise to represent the errors in the real biomass. Also, we accounted for the hierarchical relationship between different species by treating each taxonomic level as a covariate nested within a higher taxonomic level (e.g. species < genus). This approach provides estimation under incomplete tree information (e.g. missing species) or blurred information (e.g. conjecture of species), plus the biophysical environment. The GAE allowed us to quantify contribution of each different

  13. 3D Reconstruction of Frozen Plant Tissue: a unique histological analysis to image post-freeze responses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Winter hardiness in plants is the result of a complex interaction between genes, the tissue where those genes are expressed and the environment. The light microscope is a valuable tool to understand this complexity which will ultimately help researchers improve the tolerance of plants to freezing st...

  14. A global analysis of parenchyma tissue fractions in secondary xylem of seed plants.

    PubMed

    Morris, Hugh; Plavcová, Lenka; Cvecko, Patrick; Fichtler, Esther; Gillingham, Mark A F; Martínez-Cabrera, Hugo I; McGlinn, Daniel J; Wheeler, Elisabeth; Zheng, Jingming; Ziemińska, Kasia; Jansen, Steven

    2016-03-01

    Parenchyma is an important tissue in secondary xylem of seed plants, with functions ranging from storage to defence and with effects on the physical and mechanical properties of wood. Currently, we lack a large-scale quantitative analysis of ray parenchyma (RP) and axial parenchyma (AP) tissue fractions. Here, we use data from the literature on AP and RP fractions to investigate the potential relationships of climate and growth form with total ray and axial parenchyma fractions (RAP). We found a 29-fold variation in RAP fraction, which was more strongly related to temperature than with precipitation. Stem succulents had the highest RAP values (mean ± SD: 70.2 ± 22.0%), followed by lianas (50.1 ± 16.3%), angiosperm trees and shrubs (26.3 ± 12.4%), and conifers (7.6 ± 2.6%). Differences in RAP fraction between temperate and tropical angiosperm trees (21.1 ± 7.9% vs 36.2 ± 13.4%, respectively) are due to differences in the AP fraction, which is typically three times higher in tropical than in temperate trees, but not in RP fraction. Our results illustrate that both temperature and growth form are important drivers of RAP fractions. These findings should help pave the way to better understand the various functions of RAP in plants. PMID:26551018

  15. Development of a fluorescent in situ hybridization (FISH) technique for visualizing CGMMV in plant tissues.

    PubMed

    Shargil, D; Zemach, H; Belausov, E; Lachman, O; Kamenetsky, R; Dombrovsky, A

    2015-10-01

    Cucumber green mottle mosaic virus (CGMMV), which belongs to the genus Tobamovirus, is a major pathogen of cucurbit crops grown indoors and in open fields. Currently, immunology (e.g., ELISA) and molecular amplification techniques (e.g., RT-PCR) are employed extensively for virus detection in plant tissues and commercial seed lots diagnostics. In this study, a fluorescent in situ hybridization (FISH) technique, using oligonucleotides whose 5'-terminals were labeled with red cyanine 3 (Cy3) or green fluorescein isothiocyanate (FITC), was developed for the visualization of the pathogen in situ. This simple and reliable method allows detection and localization of CGMMV in the vegetative and reproductive tissues of cucumber and melon. When this technique was applied in male flowers, anther tissues were found to be infected; whereas the pollen grains were found to be virus-free. These results have meaningful epidemiological implications for the management of CGMMV, particularly with regard to virus transfer via seed and the role of insects as CGMMV vectors. PMID:26231788

  16. Robotics and dynamic image analysis for studies of gene expression in plant tissues.

    PubMed

    Hernandez-Garcia, Carlos M; Chiera, Joseph M; Finer, John J

    2010-01-01

    Gene expression in plant tissues is typically studied by destructive extraction of compounds from plant tissues for in vitro analyses. The methods presented here utilize the green fluorescent protein (gfp) gene for continual monitoring of gene expression in the same pieces of tissues, over time. The gfp gene was placed under regulatory control of different promoters and introduced into lima bean cotyledonary tissues via particle bombardment. Cotyledons were then placed on a robotic image collection system, which consisted of a fluorescence dissecting microscope with a digital camera and a 2-dimensional robotics platform custom-designed to allow secure attachment of culture dishes. Images were collected from cotyledonary tissues every hour for 100 hours to generate expression profiles for each promoter. Each collected series of 100 images was first subjected to manual image alignment using ImageReady to make certain that GFP-expressing foci were consistently retained within selected fields of analysis. Specific regions of the series measuring 300 x 400 pixels, were then selected for further analysis to provide GFP Intensity measurements using ImageJ software. Batch images were separated into the red, green and blue channels and GFP-expressing areas were identified using the threshold feature of ImageJ. After subtracting the background fluorescence (subtraction of gray values of non-expressing pixels from every pixel) in the respective red and green channels, GFP intensity was calculated by multiplying the mean grayscale value per pixel by the total number of GFP-expressing pixels in each channel, and then adding those values for both the red and green channels. GFP Intensity values were collected for all 100 time points to yield expression profiles. Variations in GFP expression profiles resulted from differences in factors such as promoter strength, presence of a silencing suppressor, or nature of the promoter. In addition to quantification of GFP intensity, the

  17. Effect of plant harvesting on the performance of constructed wetlands during winter: radial oxygen loss and microbial characteristics.

    PubMed

    Wang, Qian; Xie, Huijun; Zhang, Jian; Liang, Shuang; Ngo, Huu Hao; Guo, Wenshan; Liu, Chen; Zhao, Congcong; Li, Hao

    2015-05-01

    The aboveground tissue of plants is important for providing roots with constant photosynthetic resources. However, the aboveground biomass is usually harvested before winter to maintain the permanent removal of nutrients. In this work, the effects of harvest on plants' involvement in oxygen input as well as in microbial abundance and activity were investigated in detail. Three series of constructed wetlands with integrated plants ("unharvested"), harvested plants ("harvested"), and fully cleared plants ("cleared") were set up. Better performance was found in the unharvested units, with the radial oxygen loss (ROL) rates ranging from 0.05 to 0.59 μmol O₂/h/plant, followed by the harvested units that had relatively lower ROL rates (0.01 to 0.52 μmol O₂/h/plant). The cleared units had the lowest removal efficiency, which had no rhizome resources from the plants. The microbial population and activity were highest in the unharvested units, followed by the harvested and cleared units. Results showed that bacterial abundances and enhanced microbial activity were ten times higher on root surfaces compared with sands. These results indicate that late autumn harvesting of the aboveground biomass exhibited negative effects on plant ROL as well as on the microbial population and activity during the following winter. PMID:25520204

  18. Belowground interactions with aboveground consequences: Invasive earthworms and arbuscular mycorrhizal fungi.

    PubMed

    Paudel, Shishir; Longcore, Travis; MacDonald, Beau; McCormick, Melissa K; Szlavecz, Katalin; Wilson, Gail W T; Loss, Scot R

    2016-03-01

    A mounting body of research suggests that invasive nonnative earthworms substantially alter microbial communities, including arbuscular mycorrhizal fungi (AMF). These changes to AMF can cascade to affect plant communities and vertebrate populations. Despite these research advances, relatively little is known about (1) the mechanisms behind earthworms' effects on AMF and (2) the factors that determine the outcomes of earthworm-AMF interactions (i.e., whether AMF abundance is increased or decreased and subsequent effects on plants). We predict that AMF-mediated effects of nonnative earthworms on ecosystems are nearly universal because (1) AMF are important components of most terrestrial ecosystems, (2) nonnative earthworms have become established in nearly every type of terrestrial ecosystem, and (3) nonnative earthworms, due to their burrowing and feeding behavior, greatly affect AMF with potentially profound concomitant effects on plant communities. We highlight the multiple direct and indirect effects of nonnative earthworms on plants and review what is currently known about the interaction between earthworms and AMF. We also illustrate how the effects of nonnative earthworms on plant-AMF mutualisms can alter the structure and stability of aboveground plant communities, as well as the vertebrate communities relying on these habitats. Integrative studies that assess the interactive effects of earthworms and AMF can provide new insights into the role that belowground ecosystem engineers play in altering aboveground ecological processes. Understanding these processes may improve our ability to predict the structure of plant and animal communities in earthworm-invaded regions and to develop management strategies that limit the numerous undesired impacts of earthworms. PMID:27197388

  19. Development of Rapid Isothermal Amplification Assays for Detection of Phytophthora spp. in Plant Tissue.

    PubMed

    Miles, Timothy D; Martin, Frank N; Coffey, Michael D

    2015-02-01

    Several isothermal amplification techniques recently have been developed that are tolerant of inhibitors present in many plant extracts, which can reduce the need for obtaining purified DNA for running diagnostic assays. One such commercially available technique that has similarities with real-time polymerase chain reaction (PCR) for designing primers and a labeled probe is recombinase polymerase amplification (RPA). This technology was used to develop two simple and rapid approaches for detection of Phytophthora spp.: one genus-specific assay multiplexed with a plant internal control and the other species-specific assays for Phytophthora ramorum and P. kernoviae. All assays were tested for sensitivity (ranging from 3 ng to 1 fg of DNA) and specificity using DNA extracted from more than 136 Phytophthora taxa, 21 Pythium spp., 1 Phytopythium sp., and a wide range of plant species. The lower limit of linear detection using purified DNA was 200 to 300 fg of DNA in all pathogen RPA assays. Six different extraction buffers were tested for use during plant tissue maceration and the assays were validated in the field by collecting 222 symptomatic plant samples from over 50 different hosts. Only 56 samples were culture positive for Phytophthora spp. whereas 91 were positive using the Phytophthora genus-specific RPA test and a TaqMan real-time PCR assay. A technique for the generation of sequencing templates from positive RPA amplifications to confirm species identification was also developed. These RPA assays have added benefits over traditional technologies because they are rapid (results can be obtained in as little as 15 min), do not require DNA extraction or extensive training to complete, use less expensive portable equipment than PCR-based assays, and are significantly more specific than current immunologically based methods. This should provide a rapid, field-deployable capability for pathogen detection that will facilitate point-of-sample collection processing

  20. Impact of Lupinus leucophyllous on the nitrogen budgets of semi-arid plant communities

    SciTech Connect

    Hinds, W.T.; Hinds, N.R.

    1982-10-01

    In the semi-arid grassland on the Arid Lands Ecology Reserve on the Hanford Site in south-central Washington State, three legume flushes occurred in the past decade. Estimates of leguminous nitrogen in both native and disturbed vegetation after a flush showed that nitrogen in the legume (above-ground) doubled the amount of nitrogen associated with vascular plant tissues. 21 references, 2 tables.

  1. Potential of Chilopsis Linearis for Gold Phytomining: Using XAS to Determine Gold Reduction And Nanoparticle Formation Within Plant Tissues

    SciTech Connect

    E, Rodriguez; Parsons, J.G.; Peralta-Videa, J.R.; Cruz-Jiminez, G.; Romera-Gonzalez, J.; Sanchez-Salcido, B.E.; Saupe, G.B.; Duarte-Gardea, M.; Gardea-Torresdey, J.L.

    2009-06-04

    This study reports on the capability of the desert plant Chilopsis linearis (Cav.) Sweet (desert willow) to uptake gold (Au) from gold-enriched media at different plant-growth stages. Plants were exposed to 20, 40, 80, 160, and 320 mg Au L{sup -1} in agar-based growing media for 13, 18, 23, and 35 d. The Au content and oxidation state of Au in the plants were determined using an inductively coupled plasma/optical emission spectrometer (ICP/OES) and X-ray absorption spectroscopy (XAS), respectively. Gold concentrations ranging from 20 to 80 mg Au L{sup -1} did not significantly affect Chilopsis linearis plant growth. The concentration of gold in the plants increased as the age of the plant increased. The Au concentrations in leaves for the 20, 40, 80, and 160 mg Au L{sup -1} treatments were 32, 60, 62, and 179 mg Au kg{sup -1} dry weight mass, respectively, demonstrating the gold uptake capability of desert willow. The XAS data indicated that desert willow produced gold nanoparticles within plant tissues. Plants exposed to 160 mg Au L{sup -1} formed nanoparticles that averaged approximately 8, 35, and 18 in root, stem, and leaves, respectively. It was observed that the average size of the Au nanoparticles formed by the plants is related to the total Au concentration in tissues and their location in the plant.

  2. Effect of Thermal and Nonthermal Processing on Textural Quality of Plant Tissues.

    PubMed

    Ranganathan, Kumar; Subramanian, Vijayalakshmi; Shanmugam, Nadanasabapathi

    2016-12-01

    In the current fast revolving world, the consumption of processed food is increasing drastically. The population who depend on these processed foods are also cautious about the quality and safety of what they consume. This being the case, in order to satisfy the consumer it is the responsibility of the researcher and the manufacturer to check what happens to food on processing. Plant-derived foods such as fruits and vegetables are sensitive producers which are to be handled cautiously through each steps involved in processing, starting from harvest to storage, processing to package, transportation to distribution, till it reaches the consumer. During processing, the plant materials, which are made up of complex structural components such as lignin, cellulose, pectin, etc. undergo changes which has its effect on the quality attributes of the final product. Texture is an important quality parameter of all the sensory properties. The relation between the structure of the plant tissue and the texture of the final product is reviewed in this paper comprehensively. PMID:26046712

  3. Biological effect of radiation-degraded alginate on flower plants in tissue culture.

    PubMed

    Le, Q Luan; Nguyen, Q Hien; Nagasawa, Naotsugu; Kume, Tamikazu; Yoshii, Fumio; Nakanishi, Tomoko M

    2003-12-01

    Alginate with a weight-average molecular mass (Mw) of approx. 9.04 x 10(5) Da was irradiated at 10-200 kGy in 4% (w/v) aqueous solution. The degraded alginate product was used to study its effectiveness as a growth promoter for plants in tissue culture. Alginate irradiated at 75 kGy with an Mw of approx. 1.43 x 10(4) Da had the highest positive effect in the growth of flower plants, namely limonium, lisianthus and chrysanthemum. Treatment of plants with irradiated alginate at concentrations of 30-200 mg/l increased the shoot multiplication rate from 17.5 to 40.5% compared with control. In plantlet culture, 100 mg/l irradiated alginate supplementation enhanced shoot height (9.7-23.2%), root length (9.7-39.4%) and fresh biomass (8.1-19.4%) of chrysanthemum, lisianthus and limonium compared with that of the untreated control. The survival ratios of the transferred flower plantlets treated with irradiated alginate were almost the same as the control value under greenhouse conditions. However, better growth was attained for the treated plantlets. PMID:12901723

  4. Volatile profiling of aromatic traditional medicinal plant, Polygonum minus in different tissues and its biological activities.

    PubMed

    Ahmad, Rafidah; Baharum, Syarul Nataqain; Bunawan, Hamidun; Lee, Minki; Mohd Noor, Normah; Rohani, Emelda Roseleena; Ilias, Norashikin; Zin, Noraziah Mohamad

    2014-01-01

    The aim of this research was to identify the volatile metabolites produced in different organs (leaves, stem and roots) of Polygonum minus, an important essential oil producing crop in Malaysia. Two methods of extraction have been applied: Solid Phase Microextraction (SPME) and hydrodistillation coupled with Gas Chromatography-Mass Spectrometry (GC-MS). Approximately, 77 metabolites have been identified and aliphatic compounds contribute significantly towards the aroma and flavour of this plant. Two main aliphatic compounds: decanal and dodecanal were found to be the major contributor. Terpenoid metabolites were identified abundantly in leaves but not in the stem and root of this plant. Further studies on antioxidant, total phenolic content, anticholinesterase and antimicrobial activities were determined in the essential oil and five different extracts. The plant showed the highest DPPH radical scavenging activity in polar (ethanol) extract for all the tissues tested. For anti-acetylcholinesterase activity, leaf in aqueous extract and methanol extract showed the best acetylcholinesterase inhibitory activities. However, in microbial activity, the non-polar extracts (n-hexane) showed high antimicrobial activity against Methicillin-resistant Staphylococcus aureus (MRSA) compared to polar extracts. This study could provide the first step in the phytochemical profiles of volatile compounds and explore the additional value of pharmacology properties of this essential oil producing crop Polygonum minus. PMID:25420073

  5. A Method for Preparing Difficult Plant Tissues for Light and Electron Microscopy.

    PubMed

    Clode, Peta L

    2015-08-01

    Although the advent of microwave technologies has both improved and accelerated tissue processing for microscopy, there still remain many limitations in conventional chemical fixation, dehydration, embedding, and sectioning, particularly with regard to plant materials. The Proteaceae, a family of plants widely distributed in the Southern Hemisphere and well adapted to harsh climates and nutrient-poor soils, is a perfect example; the complexity of Proteaceae leaves means that almost no ultrastructural data are available as these are notoriously difficult to both infiltrate and section. Here, a step-by-step protocol is described that allows for the successful preparation of Banksia prionotes (Australian Proteaceae) leaves for both light and transmission electron microscopy. The method, which applies a novel combination of vibratome sectioning, microwave processing and vacuum steps, and the utilization of an ultra low viscosity resin, results in highly reproducible, well-preserved, sectionable material from which very high-quality light and electron micrographs can be obtained. With this, cellular ultrastructure from the level of a leaf through to organelle substructure can be studied. This approach will be widely applicable, both within and outside of the plant sciences, and can be readily adapted to meet specific sample requirements and imaging needs. PMID:26189464

  6. Nitrate dynamics in natural plants: insights based on the concentration and natural isotope abundances of tissue nitrate

    PubMed Central

    Liu, Xue-Yan; Koba, Keisuke; Makabe, Akiko; Liu, Cong-Qiang

    2014-01-01

    The dynamics of nitrate (NO−3), a major nitrogen (N) source for natural plants, has been studied mostly through experimental N addition, enzymatic assay, isotope labeling, and genetic expression. However, artificial N supply may not reasonably reflect the N strategies in natural plants because NO−3 uptake and reduction may vary with external N availability. Due to abrupt application and short operation time, field N addition, and isotopic labeling hinder the elucidation of in situ NO−3-use mechanisms. The concentration and natural isotopes of tissue NO−3 can offer insights into the plant NO−3 sources and dynamics in a natural context. Furthermore, they facilitate the exploration of plant NO−3 utilization and its interaction with N pollution and ecosystem N cycles without disturbing the N pools. The present study was conducted to review the application of the denitrifier method for concentration and isotope analyses of NO−3 in plants. Moreover, this study highlights the utility and advantages of these parameters in interpreting NO−3 sources and dynamics in natural plants. We summarize the major sources and reduction processes of NO−3 in plants, and discuss the implications of NO−3 concentration in plant tissues based on existing data. Particular emphasis was laid on the regulation of soil NO−3 and plant ecophysiological functions in interspecific and intra-plant NO−3 variations. We introduce N and O isotope systematics of NO−3 in plants and discuss the principles and feasibilities of using isotopic enrichment and fractionation factors; the correlation between concentration and isotopes (N and O isotopes: δ18O and Δ17O); and isotope mass-balance calculations to constrain sources and reduction of NO−3 in possible scenarios for natural plants are deliberated. Finally, we offer a preliminary framework of intraplant δ18O-NO−3 variation, and summarize the uncertainties in using tissue NO−3 parameters to interpret plant NO−3 utilization

  7. Large-scale spatial variation in plant δ2H and δ18O - altitude, longitude and tissue type effects

    NASA Astrophysics Data System (ADS)

    West, J. B.

    2012-12-01

    A critical component of the hydrologic cycle response to climatic variation and directional change at multiple scales is the role of vegetation. Plants modulate biological activities at short and long time scales in response to climate drivers like precipitation, including changing stomatal conductance and the spatial deployment of leaf and root biomass. Over longer time periods, species replacement and changes in dominant plant form (e.g., herbaceous versus woody) also have important effects on hydrologic pathways and the magnitudes of hydrologic fluxes along those pathways. The isotopic composition of plant tissues provides an important recorder of the dynamics of these interactions. While this is the case, important questions remain about the primary drivers of plant tissue hydrogen and oxygen isotope ratio variation and how to develop improved, realistic mechanistic models of plant tissue variation in δ2H and δ18O, thus limiting the inferences that can be drawn from isotopic variation in plant tissues. In particular, the relative strengths of climatic drivers versus physiologically-based variation remain the subject of significant debate. I report here on work designed to better understand how plants record this variation in plant tissues across relatively large spatial scales. A transect (approximately 1900 km long) was established from the Continental Divide in North America (at approximately 39° N latitude) to the Coast Range. Leaf, branch, and tree core samples of Pseudotsuga menziesii were collected across the transect. At each location along the transect, samples were collected from at least three elevations and on the western and eastern slopes of the target mountain range. Significant variation in δ2H and δ18O was observed and the relative effects of the drivers at multiple scales (within-site elevation and aspect and across the longitudinal transect) will be discussed in the context of current models of plant cellulose isotopic composition.

  8. Interactions between herbivory and warming in aboveground biomass production of arctic vegetation

    PubMed Central

    Pedersen, Christian; Post, Eric

    2008-01-01

    Background Many studies investigating the ecosystem effects of global climate change have focused on arctic ecosystems because the Arctic is expected to undergo the earliest and most pronounced changes in response to increasing global temperatures, and arctic ecosystems are considerably limited by low temperatures and permafrost. In these nutrient limited systems, a warmer climate is expected to increase plant biomass production, primarily through increases in shrubs over graminoids and forbs. But, the influence of vertebrate and invertebrate herbivores has been largely absent in studies investigating the effects of vegetation responses to climate change, despite the fact that herbivory can have a major influence on plant community composition, biomass and nutrient cycling. Here, we present results from a multi-annual field experiment investigating the effects of vertebrate herbivory on plant biomass response to simulated climate warming in arctic Greenland. Results The results after four years of treatments did not give any clear evidence of increased biomass of shrubs in response climate warming. Nor did our study indicate that vertebrate grazing mediated any increased domination of shrubs over other functional plant groups in response to warming. However, our results indicate an important role of insect outbreaks on aboveground biomass. Intense caterpillar foraging from a two-year outbreak of the moth Eurois occulta during two growing seasons may have concealed any treatment effects. However, there was some evidence suggesting that vertebrate herbivores constrain the biomass production of shrubs over graminoids and forbs. Conclusion Although inconclusive, our results were likely constrained by the overwhelming influence of an unexpected caterpillar outbreak on aboveground biomass. It is likely that the role of large vertebrate herbivores in vegetation response to warming will become more evident as this experiment proceeds and the plant community recovers from

  9. Quantifying Annual Aboveground Net Primary Production in the Intermountain West

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As part of a larger project, methods were developed to quantify current year growth on grasses, forbs, and shrubs. Annual aboveground net primary production (ANPP) data are needed for this project to calibrate results from computer simulation models and remote-sensing data. Measuring annual ANPP of ...

  10. Parameters affecting the efficient delivery of mesoporous silica nanoparticle materials and gold nanorods into plant tissues by the biolistic method.

    PubMed

    Martin-Ortigosa, Susana; Valenstein, Justin S; Sun, Wei; Moeller, Lorena; Fang, Ning; Trewyn, Brian G; Lin, Victor S-Y; Wang, Kan

    2012-02-01

    Applying nanotechnology to plant science requires efficient systems for the delivery of nanoparticles (NPs) to plant cells and tissues. The presence of a cell wall in plant cells makes it challenging to extend the NP delivery methods available for animal research. In this work, research is presented which establishes an efficient NP delivery system for plant tissues using the biolistic method. It is shown that the biolistic delivery of mesoporous silica nanoparticle (MSN) materials can be improved by increasing the density of MSNs through gold plating. Additionally, a DNA-coating protocol is used based on calcium chloride and spermidine for MSN and gold nanorods to enhance the NP-mediated DNA delivery. Furthermore, the drastic improvement of NP delivery is demonstrated when the particles are combined with 0.6 μm gold particles during bombardment. The methodology described provides a system for the efficient delivery of NPs into plant cells using the biolistic method. PMID:22174078

  11. Increased plant growth and copper uptake of host and non-host plants by metal-resistant and plant growth-promoting endophytic bacteria.

    PubMed

    Sun, Leni; Wang, Xiaohan; Li, Ya

    2016-05-01

    The effects of inoculation with two metal-resistant and plant growth-promoting endophytic bacteria (Burkholderia sp. GL12 and Bacillus megaterium JL35) were evaluated on the plant growth and Cu uptake in their host Elsholtzia splendens and non-host Brassica napus plants grown in natural Cu-contaminated soil. The two strains showed a high level of ACC deaminase activities. In pot experiments, inoculation with strain GL12 significantly increased root and above-ground tissue dry weights of both plants, consequently increasing the total Cu uptake of E. splendens and Brassica napus by 132% and 48.2% respectively. Inoculation with strain JL35 was found to significantly increase not only the biomass of B. napus, consequently increasing the total Cu uptake of B. napus by 31.3%, but Cu concentration of E. splendens for above-ground tissues by 318% and roots by 69.7%, consequently increasing the total Cu uptake of E. splendens by 223%. The two strains could colonize the rhizosphere soils and root interiors of both plants. Notably, strain JL35 could colonize the shoot tissues and significantly increase the translocation factors and bioaccumulation factors of E. splendens. These results suggested that Burkholderia sp. GL12 and B. megaterium JL35 were valuable bacterial resource which had the potential in improving the efficiency of Cu phytoextraction by E. splendens and B. napus in a natural Cu-contaminated soil. PMID:26587767

  12. Nanoparticles as Smart Treatment-delivery Systems in Plants: Assessment of Different Techniques of Microscopy for their Visualization in Plant Tissues

    PubMed Central

    González-Melendi, P.; Fernández-Pacheco, R.; Coronado, M. J.; Corredor, E.; Testillano, P. S.; Risueño, M. C.; Marquina, C.; Ibarra, M. R.; Rubiales, D.; Pérez-de-Luque, A.

    2008-01-01

    Background and Aims The great potential of using nanodevices as delivery systems to specific targets in living organisms was first explored for medical uses. In plants, the same principles can be applied for a broad range of uses, in particular to tackle infections. Nanoparticles tagged to agrochemicals or other substances could reduce the damage to other plant tissues and the amount of chemicals released into the environment. To explore the benefits of applying nanotechnology to agriculture, the first stage is to work out the correct penetration and transport of the nanoparticles into plants. This research is aimed (a) to put forward a number of tools for the detection and analysis of core-shell magnetic nanoparticles introduced into plants and (b) to assess the use of such magnetic nanoparticles for their concentration in selected plant tissues by magnetic field gradients. Methods Cucurbita pepo plants were cultivated in vitro and treated with carbon-coated Fe nanoparticles. Different microscopy techniques were used for the detection and analysis of these magnetic nanoparticles, ranging from conventional light microscopy to confocal and electron microscopy. Key Results Penetration and translocation of magnetic nanoparticles in whole living plants and into plant cells were determined. The magnetic character allowed nanoparticles to be positioned in the desired plant tissue by applying a magnetic field gradient there; also the graphitic shell made good visualization possible using different microscopy techniques. Conclusions The results open a wide range of possibilities for using magnetic nanoparticles in general plant research and agronomy. The nanoparticles can be charged with different substances, introduced within the plants and, if necessary, concentrated into localized areas by using magnets. Also simple or more complex microscopical techniques can be used in localization studies. PMID:17998213

  13. [Aboveground architecture and biomass distribution of Quercus variabilis].

    PubMed

    Yu, Bi-yun; Zhang, Wen-hui; Hu, Xiao-jing; Shen, Jia-peng; Zhen, Xue-yuan; Yang, Xiao-zhou

    2015-08-01

    The aboveground architecture, biomass and its allocation, and the relationship between architecture and biomass of Quercus variabilis of different diameter classes in Shangluo, south slope of Qinling Mountains were researched. The results showed that differences existed in the aboveground architecture and biomass allocation of Q. variabilis of different diameter classes. With the increase of diameter class, tree height, DBH, and crown width increased gradually. The average decline rate of each diameter class increased firstly then decreased. Q. variabilis overall bifurcation ratio and stepwise bifurcation ratio increased then declined. The specific leaf areas of Q. variabilis of all different diameter classes at vertical direction were 0.02-0.03, and the larger values of leaf mass ratio, LAI and leaf area ratio at vertical direction in diameter level I , II, III appeared in the middle and upper trunk, while in diameter level IV, V, VI, they appeared in the central trunk, with the increase of diameter class, there appeared two peaks in vertical direction, which located in the lower and upper trunk. The trunk biomass accounted for 71.8%-88.4% of Q. variabilis aboveground biomass, while the branch biomass accounted for 5.8%-19.6%, and the leaf biomass accounted for 4.2%-8.6%. With the increase of diameter class, stem biomass proportion of Q. variabilis decreased firstly then increased, while the branch and leaf biomass proportion showed a trend that increased at first then decreased, and then increased again. The aboveground biomass of Q. variabilis was significantly positively correlated to tree height, DBH, crown width and stepwise bifurcation ratio (R2:1), and positively related to the overall bifurcation ratio and stepwise bifurcation ratio (R3:2), but there was no significant correlation. Trunk biomass and total biomass aboveground were negatively related to the trunk decline rate, while branch biomass and leaf biomass were positively related to trunk decline

  14. Assessing aboveground tropical forest biomass using Google Earth canopy images.

    PubMed

    Ploton, Pierre; Pélissier, Raphaël; Proisy, Christophe; Flavenot, Théo; Barbier, Nicolas; Rai, S N; Couteron, Pierre

    2012-04-01

    Reducing Emissions from Deforestation and Forest Degradation (REDD) in efforts to combat climate change requires participating countries to periodically assess their forest resources on a national scale. Such a process is particularly challenging in the tropics because of technical difficulties related to large aboveground forest biomass stocks, restricted availability of affordable, appropriate remote-sensing images, and a lack of accurate forest inventory data. In this paper, we apply the Fourier-based FOTO method of canopy texture analysis to Google Earth's very-high-resolution images of the wet evergreen forests in the Western Ghats of India in order to (1) assess the predictive power of the method on aboveground biomass of tropical forests, (2) test the merits of free Google Earth images relative to their native commercial IKONOS counterparts and (3) highlight further research needs for affordable, accurate regional aboveground biomass estimations. We used the FOTO method to ordinate Fourier spectra of 1436 square canopy images (125 x 125 m) with respect to a canopy grain texture gradient (i.e., a combination of size distribution and spatial pattern of tree crowns), benchmarked against virtual canopy scenes simulated from a set of known forest structure parameters and a 3-D light interception model. We then used 15 1-ha ground plots to demonstrate that both texture gradients provided by Google Earth and IKONOS images strongly correlated with field-observed stand structure parameters such as the density of large trees, total basal area, and aboveground biomass estimated from a regional allometric model. Our results highlight the great potential of the FOTO method applied to Google Earth data for biomass retrieval because the texture-biomass relationship is only subject to 15% relative error, on average, and does not show obvious saturation trends at large biomass values. We also provide the first reliable map of tropical forest aboveground biomass predicted

  15. The safety assessment of food ingredients derived from plant cell, tissue and organ cultures: a review.

    PubMed

    Murthy, Hosakatte Niranjana; Georgiev, Milen I; Park, So-Young; Dandin, Vijayalaxmi S; Paek, Kee-Yoeup

    2015-06-01

    Plant cell, tissue and organ cultures (PCTOC) have become an increasingly attractive alternative for the production of various high molecular weight molecules which are used as flavourings, fragrances, colouring agents and food additives. Although PCTOC products are cultivated in vitro in a contamination free environment, the raw material produced from PCTOC may contain many components apart from the target compound. In some cases, PCTOC raw materials may also carry toxins, which may be naturally occurring or accumulated during the culture process. Assessment of the safety of PCTOC products is, therefore, a priority of the biotech industries involved in their production. The safety assessment involves the evaluation of starting material, production process and the end product. Before commercialisation, PCTOC products should be evaluated for their chemical and biological properties, as well as for their toxicity. In this review, measures and general criteria for biosafety evaluation of PCTOC products are addressed and thoroughly discussed. PMID:25624252

  16. Simultaneous isolation of intact mitochondria and chloroplasts from a single pulping of plant tissue.

    PubMed

    Rödiger, Anja; Baudisch, Bianca; Klösgen, Ralf Bernd

    2010-05-15

    Isolated organelles are suitable tools for the investigation of organelle function. However, if the properties of different organelles are to be compared, analysis is generally impeded by the fact that the organelles are isolated independently from each other from different specimens, different tissues or even different plants, i.e. the organelles have been exposed to different conditions during growth and development. Here we describe a method to isolate intact chloroplasts and mitochondria simultaneously from a single pulping of pea leaves, which results in organelles with an essentially identical physiological background. The functionality of the isolated chloroplasts and mitochondria is demonstrated by protein transport experiments, which yield results identical to those obtained with independently isolated organelles. With slight modifications, the method is also successfully applied to organelles from potato and spinach, which implies that it may be generally applicable to organelles from many different species. PMID:20045215

  17. Isolation of functional RNA from plant tissues rich in phenolic compounds.

    PubMed

    Schneiderbauer, A; Sandermann, H; Ernst, D

    1991-08-15

    A method for the isolation of RNA from different tissues of trees (seedlings, saplings, and adult trees) is described. Using this procedure it is possible to remove large amounts of disturbing polyphenolic compounds from nucleic acids. The method involves an acetone treatment of the freeze-dried and powdered plant material, the use of high salt concentrations in the extraction buffer and an aqueous two-phase system. These steps were combined with the conventional phenol/chloroform extraction and CsCl centrifugation. The method has been successfully applied to the isolation and purification of RNA from pine (Pinus sylvestris L. and Pinus mugo Turr.), Norway spruce (Picea abies L.), and beech (Fagus sylvatica L.). The functional quality of RNA extracted by this procedure has been characterized by its uv spectrum, by agarose gel electrophoresis with ethidium bromide staining, Northern blot hybridization, and in vitro translation. PMID:1719845

  18. Application of SEM and EDX in studying biomineralization in plant tissues.

    PubMed

    He, Honghua; Kirilak, Yaowanuj

    2014-01-01

    This chapter describes protocols using formalin-acetic acid-alcohol (FAA) to fix plant tissues for studying biomineralization by means of scanning electron microscopy (SEM) and qualitative energy-dispersive X-ray microanalysis (EDX). Specimen preparation protocols for SEM and EDX mainly include fixation, dehydration, critical point drying (CPD), mounting, and coating. Gold-coated specimens are used for SEM imaging, while gold- and carbon-coated specimens are prepared for qualitative X-ray microanalyses separately to obtain complementary information on the elemental compositions of biominerals. During the specimen preparation procedure for SEM, some biominerals may be dislodged or scattered, making it difficult to determine their accurate locations, and light microscopy is used to complement SEM studies. Specimen preparation protocols for light microscopy generally include fixation, dehydration, infiltration and embedding with resin, microtome sectioning, and staining. In addition, microwave processing methods are adopted here to speed up the specimen preparation process for both SEM and light microscopy. PMID:24357384

  19. Regeneration of whole fertile plants from 30,000-y-old fruit tissue buried in Siberian permafrost

    PubMed Central

    Yashina, Svetlana; Gubin, Stanislav; Maksimovich, Stanislav; Yashina, Alexandra; Gakhova, Edith; Gilichinsky, David

    2012-01-01

    Whole, fertile plants of Silene stenophylla Ledeb. (Caryophyllaceae) have been uniquely regenerated from maternal, immature fruit tissue of Late Pleistocene age using in vitro tissue culture and clonal micropropagation. The fruits were excavated in northeastern Siberia from fossil squirrel burrows buried at a depth of 38 m in undisturbed and never thawed Late Pleistocene permafrost sediments with a temperature of −7 °C. Accelerator mass spectrometry (AMS) radiocarbon dating showed fruits to be 31,800 ± 300 y old. The total γ-radiation dose accumulated by the fruits during this time was calculated as 0.07 kGy; this is the maximal reported dose after which tissues remain viable and seeds still germinate. Regenerated plants were brought to flowering and fruiting and they set viable seeds. At present, plants of S. stenophylla are the most ancient, viable, multicellular, living organisms. Morphophysiological studies comparing regenerated and extant plants obtained from modern seeds of the same species in the same region revealed that they were distinct phenotypes of S. stenophylla. The first generation cultivated from seeds obtained from regenerated plants progressed through all developmental stages and had the same morphological features as parent plants. The investigation showed high cryoresistance of plant placental tissue in permafrost. This natural cryopreservation of plant tissue over many thousands of years demonstrates a role for permafrost as a depository for an ancient gene pool, i.e., preexisting life, which hypothetically has long since vanished from the earth's surface, a potential source of ancient germplasm, and a laboratory for the study of rates of microevolution. PMID:22355102

  20. Exploring the possibility of estimating the aboveground biomass of Vallisneria spiralis L. using Landsat TM image in Dahuchi, Jiangxi Province, China

    NASA Astrophysics Data System (ADS)

    Wu, Guofeng; de Leeuw, Jan; Skidmore, Andrew K.; Prins, Herbert H. T.; Liu, Yaolin

    2005-10-01

    The provision of food to breeding and migrating waterfowl is one of the major functions of submerged aquatic vegetation in shallow lakes. Vallisneria spiralis L. is a submerged aquatic plant species widely distributed within Jiangxi Poyang Lake National Nature Reserve, China. More than 95% of the world population of the endangered Siberian crane as well as significant numbers of Bewick's swan and swan goose over winter in this area, while foraging on the tubers of Vallisneria. The objective of this paper was to explore the possibility of estimating the aboveground biomass of Vallisneria in Dahuchi Lake using Landsat TM image. The relations between aboveground biomass and the bands of a Landsat TM image and their derived variables were investigated using uni- and multivariate linear and non-linear regression models. The results revealed significant but very weak relations between aboveground biomass and the remotely sensed variables. Hence Landsat TM imagery offered little potential to predict aboveground biomass of Vallisneria in this particular region. Possible reasons which could have caused these results were discussed, including: 1) the possible influence of suspended matter in the water; 2) the less accurate field sampling; 3) the limitations of spatial and spectral resolutions of Landsat TM image; 4) the methods used are not appropriate; 5) the homogeneously spatial distribution of aboveground biomass. We propose considering two alternative methods to improve the estimation of aboveground biomass of Vallisneria. First of all, results might be improved while combining alternative data sources (hyperspectral or high spatial resolution images) with innovative methods and more accurate sampling data; Secondly we propose assessing aboveground biomass while using productivity simulation models of submerged aquatic vegetation integrated with geographic information system (GIS) and remote sensing.

  1. Characterisation of antioxidants in photosynthetic and non-photosynthetic leaf tissues of variegated Pelargonium zonale plants.

    PubMed

    Vidović, M; Morina, F; Milić-Komić, S; Vuleta, A; Zechmann, B; Prokić, Lj; Veljović Jovanović, S

    2016-07-01

    Hydrogen peroxide is an important signalling molecule, involved in regulation of numerous metabolic processes in plants. The most important sources of H2 O2 in photosynthetically active cells are chloroplasts and peroxisomes. Here we employed variegated Pelargonium zonale to characterise and compare enzymatic and non-enzymatic components of the antioxidative system in autotrophic and heterotrophic leaf tissues at (sub)cellular level under optimal growth conditions. The results revealed that both leaf tissues had specific strategies to regulate H2 O2 levels. In photosynthetic cells, the redox regulatory system was based on ascorbate, and on the activities of thylakoid-bound ascorbate peroxidase (tAPX) and catalase. In this leaf tissue, ascorbate was predominantly localised in the nucleus, peroxisomes, plastids and mitochondria. On the other hand, non-photosynthetic cells contained higher glutathione content, mostly located in mitochondria. The enzymatic antioxidative system in non-photosynthetic cells relied on the ascorbate-glutathione cycle and both Mn and Cu/Zn superoxide dismutase. Interestingly, higher content of ascorbate and glutathione, and higher activities of APX in the cytosol of non-photosynthetic leaf cells compared to the photosynthetic ones, suggest the importance of this compartment in H2 O2 regulation. Together, these results imply different regulation of processes linked with H2 O2 signalling at subcellular level. Thus, we propose green-white variegated leaves as an excellent system for examination of redox signal transduction and redox communication between two cell types, autotrophic and heterotrophic, within the same organ. PMID:26712503

  2. In vivo monitoring of seeds and plant-tissue water absorption using optical coherence tomography and optical coherence microscopy

    NASA Astrophysics Data System (ADS)

    Sapozhnikova, Veronika V.; Kutis, Irina S.; Kutis, Sergey D.; Kuranov, Roman V.; Gelikonov, Grigory V.; Shabanov, Dmitry V.; Kamensky, Vladislav A.

    2004-07-01

    First experimental results on OCT imaging of internal structure of plant tissues and in situ OCT monitoring of plant tissue regeneration at different water supply are reported. Experiments for evaluating OCT capabilities were performed on Tradescantia. The investigation of seeds swelling was performed on wheat seeds (Triticum L.), barley seeds (Hordeum L.), long-fibred flax seeds (Linum usitatissimum L.) and cucumber seeds (Cucumis sativus L.). These OCT images correlate with standard microscopy data from the same tissue regions. Seeds were exposed to a low-intensity physical factor-the pulsed gradient magnetic field (GMF) with pulse duration 0.1 s and maximum amplitude 5 mT (4 successive pulses during 0.4 s). OCT and OCM enable effective monitoring of fast reactions in plants and seeds at different water supply.

  3. Net changes in aboveground woody carbon stock in western juniper woodlands, 1946-1998

    NASA Astrophysics Data System (ADS)

    Strand, Eva K.; Vierling, Lee A.; Smith, Alistair M. S.; Bunting, Stephen C.

    2008-03-01

    Although regional increases in woody plant cover in semiarid ecosystems have been identified as a worldwide phenomenon affecting the global carbon budget, quantifying the impact of these vegetation shifts on C pools and fluxes is challenging. Challenges arise because woody encroachment is governed by ecological processes that occur at fine spatial resolutions (1-10 m) and, in many cases, at slow (decadal-scale) temporal rates over large areas. We therefore analyzed time series aerial photography, which exhibits both the necessary spatial precision and temporal extent, to quantify the expansion of western juniper into sagebrush steppe landscapes in southwestern Idaho. We established upper and lower bounds of aboveground woody carbon change across the landscape via two-dimensional spatial wavelet analysis, image texture analysis, and field data collection. Forty-eight 100-ha blocks across a 330,000-ha region were stratified by topography, soil characteristics, and land stewardship for analyses. Across the area we estimate aboveground woody carbon accumulation rates of 3.3 gCm-2yr-1 and 10.0 gCm-2yr-1 using the wavelet and texture method, respectively, during the time period 1946-1998. Carbon accumulation rates were significantly affected by soil properties and were highly dependent on the spatial and temporal scales of analysis. For example, at a 100-ha scale the aboveground carbon accumulation varied from -1.7 to 9.9 gCm-2yr-1, while at the 1-ha scale the range of variability increased to -11 to 22 gCm-2yr-1. These values are an order of magnitude lower than those previously suggested due to woody encroachment, highlighting the need for examining multiple spatial scales when accounting for changes in terrestrial carbon storage.

  4. Fate of polycyclic aromatic hydrocarbons in plant-soil systems: Plant responses to a chemical stress in the root zone

    SciTech Connect

    Hoylman, A.M.; Walton, B.T.

    1994-01-01

    Under laboratory conditions selected to maximize root uptake, plant tissue distribution of PAH-derived {sup 14}C was largely limited to root tissue of Malilotus alba. These results suggest that plant uptake of PAHs from contaminated soil via roots, and translocation to aboveground plant tissues (stems and leaves), is a limited mechanism for transport into terrestrial food chains. However, these data also indicate that root surface sorption of PAHs may be important for plants grown in soils containing elevated concentration PAHs. Root surface sorption of PAHs may be an important route of exposure for plants in soils containing elevated concentrations of PAHS. Consequently, the root-soil interface may be the site of plant-microbial interactions in response to a chemical stress. In this study, evidence of a shift in carbon allocation to the root zone of plants exposed to phenanthrene and corresponding increases in soil respiration and heterotrophic plate counts provide evidence of a plant-microbial response to a chemical stress. The results of this study establish the importance of the root-soil interface for plants growing in PAH contaminated soil and indicate the existence of plant-microbial interactions in response to a chemical stress. These results may provide new avenues of inquiry for studies of plant toxicology, plant-microbial interactions in the rhizosphere, and environmental fates of soil contaminants. In addition, the utilization of plants to enhance the biodegradation of soil contaminants may require evaluation of plant physiological changes and plant shifts in resource allocation.

  5. Aboveground production does not increase after ten years of elevated CO2 in the Mojave Desert

    NASA Astrophysics Data System (ADS)

    Newingham, B. A.; Vanier, C. H.; Charlet, D.; Zitzer, S. F.; Smith, S. D.

    2011-12-01

    Elevated atmospheric CO2 ([CO2]) is assumed to increase primary production, particularly in desert systems through stimulatory effects on plant water-use efficiency. We examined the effects of elevated [CO2] at the Nevada Desert FACE (Free-air CO2 Enrichment) Facility (NDFF) in an intact Mojave Desert ecosystem. At the NDFF, ambient and elevated [CO2] levels were 360 and 550 μmol mol-1 [CO2], respectively. CO2 treatments were applied continuously from 1997-2007 in intact plots 25 m in diameter. While other studies focused on soil and root responses to elevated [CO2], our study focused on aboveground production of annuals and perennial plants. In 1997, diameters and heights of all perennial individuals were recorded and mapped. In 2007, diameters and heights were re-measured and aboveground biomass was harvested for every mapped perennial individual. Harvest data were used to construct regressions for twenty perennial species to predict starting biomass based on diameters and heights. Annual plants were harvested yearly at peak biomass from permanent transects. We found no significant effect of elevated [CO2] on total perennial plant biomass or cover at the end of the experiment. Regardless of [CO2] treatment, perennial cover increased while total biomass did not change over the ten years of the experiment. Perennial biomass allocation to vegetative, twig and woody biomass was not differentially affected by elevated [CO2], although leaf area index increased under elevated [CO2]. Similarly, there was no consistent elevated [CO2] effect on yearly production of annual (ephemeral) plants, although an exotic grass (Bromus madritensis subsp. rubens) exhibited a higher relative stimulation in production at elevated [CO2] than did native dicot and grass species. Other studies in our research group have shown that increases in production are only seen in wet years during the ten-year period of CO2 treatments at the NDFF, and so future effects of rising [CO2] may primarily

  6. Multi-scale simulation of plant tissue deformation using a model for individual cell mechanics.

    PubMed

    Ghysels, P; Samaey, G; Tijskens, B; Van Liedekerke, P; Ramon, H; Roose, D

    2009-01-01

    We present a micro-macro method for the simulation of large elastic deformations of plant tissue. At the microscopic level, we use a mass-spring model to describe the geometrical structure and basic properties of individual plant cells. The macroscopic domain is discretized using standard finite elements, in which the macroscopic material properties (the stress-strain relation) are not given in analytical form, but are computed using the microscopic model in small subdomains, called representative volume elements (RVEs), centered around the macroscopic quadrature points. The boundary conditions for these RVEs are derived from the macroscopic deformation gradient. The computation of the macroscopic stress tensor is based on the definition of virial stress, as defined in molecular dynamics. The anisotropic Eulerian elasticity tensor is estimated using a forward finite difference approximation for the Truesdell rate of the Cauchy stress tensor. We investigate the influence of the size of the RVE and the boundary conditions. This multi-scale method converges to the solution of the full microscopic simulation, for both globally and adaptively refined finite element meshes, and achieves a significant speedup compared to the full microscopic simulation. PMID:19321921

  7. Micro-scale elemental partition in tissues of the aquatic plant Lemna minor L. exposed to highway drainage water

    NASA Astrophysics Data System (ADS)

    Mendes Godinho, R.; Raimundo, J.; Vale, C.; Anes, B.; Brito, P.; Alves, L. C.; Pinheiro, T.

    2013-07-01

    In the scope of a monitoring program to assess the environmental impact of automobile traffic over one main bridge in Lisbon, both water and duckweed (Lemna minor L.) were sampled from the road drainage tanks and analyzed for chemical elements. Plants uptake Cr, Mn, Cu, and Zn metals from rain water draining the bridge road. Nuclear microprobe elemental maps of cryosections of L. minor tissues showed that incorporated elements were internalized in fronds of the plant. This approach at micrometer level allows a better knowledge of the elemental tissue partitioning in this biomonitor organism.

  8. A multi-tissue genome-scale metabolic modeling framework for the analysis of whole plant systems

    PubMed Central

    Gomes de Oliveira Dal'Molin, Cristiana; Quek, Lake-Ee; Saa, Pedro A.; Nielsen, Lars K.

    2015-01-01

    Genome scale metabolic modeling has traditionally been used to explore metabolism of individual cells or tissues. In higher organisms, the metabolism of individual tissues and organs is coordinated for the overall growth and well-being of the organism. Understanding the dependencies and rationale for multicellular metabolism is far from trivial. Here, we have advanced the use of AraGEM (a genome-scale reconstruction of Arabidopsis metabolism) in a multi-tissue context to understand how plants grow utilizing their leaf, stem and root systems across the day-night (diurnal) cycle. Six tissue compartments were created, each with their own distinct set of metabolic capabilities, and hence a reliance on other compartments for support. We used the multi-tissue framework to explore differences in the “division-of-labor” between the sources and sink tissues in response to: (a) the energy demand for the translocation of C and N species in between tissues; and (b) the use of two distinct nitrogen sources (NO−3 or NH+4). The “division-of-labor” between compartments was investigated using a minimum energy (photon) objective function. Random sampling of the solution space was used to explore the flux distributions under different scenarios as well as to identify highly coupled reaction sets in different tissues and organelles. Efficient identification of these sets was achieved by casting this problem as a maximum clique enumeration problem. The framework also enabled assessing the impact of energetic constraints in resource (redox and ATP) allocation between leaf, stem, and root tissues required for efficient carbon and nitrogen assimilation, including the diurnal cycle constraint forcing the plant to set aside resources during the day and defer metabolic processes that are more efficiently performed at night. This study is a first step toward autonomous modeling of whole plant metabolism. PMID:25657653

  9. Inter-organ defense networking: Leaf whitefly sucking elicits plant immunity to crown gall disease caused by Agrobacterium tumefaciens.

    PubMed

    Park, Yong-Soon; Ryu, Choong-Min

    2015-01-01

    Plants have elaborate defensive machinery to protect against numerous pathogens and insects. Plant hormones function as modulators of defensive mechanisms to maintain plant resistance to natural enemies. Our recent study suggests that salicylic acid (SA) is the primary phytohormone regulating plant responses to Agrobacterium tumefaciens infection. Tobacco (Nicotiana benthamiana Domin.) immune responses against Agrobacterium-mediated crown gall disease were activated by exposure to the sucking insect whitefly, which stimulated SA biosynthesis in aerial tissues; in turn, SA synthesized in aboveground tissues systemically modulated SA secretion in root tissues. Further investigation revealed that endogenous SA biosynthesis negatively modulated Agrobacterium-mediated plant genetic transformation. Our study provides novel evidence that activation of the SA-signaling pathway mediated by a sucking insect infestation has a pivotal role in subsequently attenuating Agrobacterium infection. These results demonstrate new insights into interspecies cross-talking among insects, plants, and soil bacteria. PMID:26357873

  10. Inter-organ defense networking: Leaf whitefly sucking elicits plant immunity to crown gall disease caused by Agrobacterium tumefaciens

    PubMed Central

    Park, Yong-Soon; Ryu, Choong-Min

    2015-01-01

    Plants have elaborate defensive machinery to protect against numerous pathogens and insects. Plant hormones function as modulators of defensive mechanisms to maintain plant resistance to natural enemies. Our recent study suggests that salicylic acid (SA) is the primary phytohormone regulating plant responses to Agrobacterium tumefaciens infection. Tobacco (Nicotiana benthamiana Domin.) immune responses against Agrobacterium-mediated crown gall disease were activated by exposure to the sucking insect whitefly, which stimulated SA biosynthesis in aerial tissues; in turn, SA synthesized in aboveground tissues systemically modulated SA secretion in root tissues. Further investigation revealed that endogenous SA biosynthesis negatively modulated Agrobacterium-mediated plant genetic transformation. Our study provides novel evidence that activation of the SA-signaling pathway mediated by a sucking insect infestation has a pivotal role in subsequently attenuating Agrobacterium infection. These results demonstrate new insights into interspecies cross-talking among insects, plants, and soil bacteria. PMID:26357873

  11. Uncertainty Analysis in Large Area Aboveground Biomass Mapping

    NASA Astrophysics Data System (ADS)

    Baccini, A.; Carvalho, L.; Dubayah, R.; Goetz, S. J.; Friedl, M. A.

    2011-12-01

    Satellite and aircraft-based remote sensing observations are being more frequently used to generate spatially explicit estimates of aboveground carbon stock of forest ecosystems. Because deforestation and forest degradation account for circa 10% of anthropogenic carbon emissions to the atmosphere, policy mechanisms are increasingly recognized as a low-cost mitigation option to reduce carbon emission. They are, however, contingent upon the capacity to accurately measures carbon stored in the forests. Here we examine the sources of uncertainty and error propagation in generating maps of aboveground biomass. We focus on characterizing uncertainties associated with maps at the pixel and spatially aggregated national scales. We pursue three strategies to describe the error and uncertainty properties of aboveground biomass maps, including: (1) model-based assessment using confidence intervals derived from linear regression methods; (2) data-mining algorithms such as regression trees and ensembles of these; (3) empirical assessments using independently collected data sets.. The latter effort explores error propagation using field data acquired within satellite-based lidar (GLAS) acquisitions versus alternative in situ methods that rely upon field measurements that have not been systematically collected for this purpose (e.g. from forest inventory data sets). A key goal of our effort is to provide multi-level characterizations that provide both pixel and biome-level estimates of uncertainties at different scales.

  12. Below-ground plant–fungus network topology is not congruent with above-ground plant–animal network topology

    PubMed Central

    Toju, Hirokazu; Guimarães, Paulo R.; Olesen, Jens M.; Thompson, John N.

    2015-01-01

    In nature, plants and their pollinating and/or seed-dispersing animals form complex interaction networks. The commonly observed pattern of links between specialists and generalists in these networks has been predicted to promote species coexistence. Plants also build highly species-rich mutualistic networks below ground with root-associated fungi, and the structure of these plant–fungus networks may also affect terrestrial community processes. By compiling high-throughput DNA sequencing data sets of the symbiosis of plants and their root-associated fungi from three localities along a latitudinal gradient, we uncovered the entire network architecture of these interactions under contrasting environmental conditions. Each network included more than 30 plant species and hundreds of mycorrhizal and endophytic fungi belonging to diverse phylogenetic groups. The results were consistent with the notion that processes shaping host-plant specialization of fungal species generate a unique linkage pattern that strongly contrasts with the pattern of above-ground plant–partner networks. Specifically, plant–fungus networks lacked a “nested” architecture, which has been considered to promote species coexistence in plant–partner networks. Rather, the below-ground networks had a conspicuous “antinested” topology. Our findings lead to the working hypothesis that terrestrial plant community dynamics are likely determined by the balance between above-ground and below-ground webs of interspecific interactions. PMID:26601279

  13. An intact cuticle in distal tissues is essential for the induction of systemic acquired resistance in plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Systemic acquired resistance (SAR) immunizes distal tissues of plants against secondary infections. We report that an acyl carrier protein, ACP4, is essential for perception but not generation of the SAR signal in Arabidopsis. A mutation in acp4 reduces the fatty acid flux, resulting in impaired cut...

  14. Chromium localization in plant tissues of Lycopersicum esculentum Mill using ICP-MS and ion microscopy (SIMS)

    NASA Astrophysics Data System (ADS)

    Mangabeira, Pedro Antonio; Gavrilov, Konstantin L.; Almeida, Alex-Alan Furtado de; Oliveira, Arno Heeren; Severo, Maria Isabel; Rosa, Tiago Santana; Silva, Delmira da Costa; Labejof, Lise; Escaig, Françoise; Levi-Setti, Riccardo; Mielke, Marcelo Schramm; Loustalot, Florence Grenier; Galle, Pierre

    2006-03-01

    High-resolution imaging secondary ion mass spectrometry (HRI-SIMS) in combination with inductively coupled plasma mass spectrometry (ICP-MS) were utilised to determine specific sites of chromium concentration in tomato plant tissues (roots, stems and leaves). The tissues were obtained from plants grown for 2 months in hydroponic conditions with Cr added in a form chromium salt (CrCl 3·6H 2O) to concentrations of 25 and 50 mg/L. The chemical fixation procedure used permit to localize only insoluble or strongly bound Cr components in tomato plant tissue. In this work no quantitative SIMS analysis was made. HRI-SIMS analysis revealed that the transport of chromium is restricted to the vascular system of roots, stems and leaves. No Cr was detected in epidermis, palisade parenchyma and spongy parenchyma cells of the leaves. The SIMS-300 spectra obtained from the tissues confirm the HRI-SIMS observations. The roots, and especially walls of xylem vessels, were determined as the principal site of chromium accumulation in tomato plants.

  15. Evolutionary and tissue-specific control of expression of multiple acyl-carrier protein isoforms in plants and bacteria.

    PubMed

    Battey, J F; Ohlrogge, J B

    1990-02-01

    We have examined the occurrence of multiple acyl-carrier protein (ACP), isoforms in evolutionarily diverse species of higher and lower plants. Isoforms were resolved by native polyacrylamide gel electrophoresis (PAGE), and were detected by Western blotting or fluorography of [(3)H]-palmitate-labelled ACPs. Multiple isoforms of ACP were found in leaf tissue of the monocotyledons Avena sativa and Hordeum vulgare and dicotyledons Arabidopsis thaliana, Cuphea wrightii, and Brassica napus. Lower vascular plants including the lycopod Selaginella krausseriana, the gymnosperms Ephedra sp. and Dioon edule, the ferns Davallia feejensis and Marsilea sp. and the most primitive known extant vascular plant, Psilotum nudum, were all found to have multiple ACP isoforms, as were the nonvascular liverworts, Lunularia sp. and Marchantia sp. and the moss, Polytrichum sp. Therefore, the development of ACP isoforms appears to have occurred early in plant evolution. However, we could detect only a single electrophoretic form of ACP in the unicellular algae Chlamydomonas reinhardtii and Dunaliella tertiolecta and the photosynthetic cyanobacteria Synechocystis strain 6803 and Agmnellum quadruplicatum. Thus, multiple forms of ACP do not occur in all photosynthetic organisms but may be associated with multicellular plants. We have also examined tissue specificity and light control over the expression of ACP isoforms. The relative abundance of multiple forms of ACP in leaf of Spinacia and Avena was altered very little by light. Rather, the different patterns of ACP isoforms were primarily dependent on the tissue type. PMID:24202013

  16. Development and Application of a High-Resolution Imaging Mass Spectrometer for the Study of Plant Tissues.

    PubMed

    Takahashi, Katsutoshi; Kozuka, Toshiaki; Anegawa, Aya; Nagatani, Akira; Mimura, Tetsuro

    2015-07-01

    Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI) or imaging mass spectrometry (imaging MS) has been a powerful tool to map the spatial distribution of molecules on the surface of biological materials. This technique has frequently been applied to animal tissue slices for the purpose of mapping proteins, peptides, lipids, sugars or small metabolites to find disease-specific biomarkers or to study drug metabolism. Recently, it has also been applied to intact plant tissues or thin slices thereof using commercial mass spectrometers. The present work is concerned with the refinement of MALDI/laser desorption/ionization (LDI)-Fourier transform ion cyclotron resonance (FTICR)-MS incorporating certain specific features namely, ultra-high mass resolution (>100,000), ultra-high molecular mass accuracy (<1 p.p.m.) and high spatial resolution (<10 µm) for imaging MS of plant tissues. Employing an in-house built mass spectrometer, the imaging MS analysis of intact Arabidopsis thaliana tissues, namely etiolated seedlings and roots of seedlings, glued to a small transparent ITO (indium tin oxide)-coated conductive glass was performed. A matrix substance was applied to the vacuum-dried intact tissues by sublimation prior to the imaging MS analysis. The images of various small metabolites representing their two-dimensional distribution on the dried intact tissues were obtained with or without different matrix substances. The effects of MALDI matrices on the ionization of small metabolites during imaging MS acquisition are discussed. PMID:26063395

  17. Aboveground total and green biomass of dryland shrub derived from terrestrial laser scanning

    NASA Astrophysics Data System (ADS)

    Olsoy, Peter J.; Glenn, Nancy F.; Clark, Patrick E.; Derryberry, DeWayne R.

    2014-02-01

    Sagebrush (Artemisia tridentata), a dominant shrub species in the sagebrush-steppe ecosystem of the western US, is declining from its historical distribution due to feedbacks between climate and land use change, fire, and invasive species. Quantifying aboveground biomass of sagebrush is important for assessing carbon storage and monitoring the presence and distribution of this rapidly changing dryland ecosystem. Models of shrub canopy volume, derived from terrestrial laser scanning (TLS) point clouds, were used to accurately estimate aboveground sagebrush biomass. Ninety-one sagebrush plants were scanned and sampled across three study sites in the Great Basin, USA. Half of the plants were scanned and destructively sampled in the spring (n = 46), while the other half were scanned again in the fall before destructive sampling (n = 45). The latter set of sagebrush plants was scanned during both spring and fall to further test the ability of the TLS to quantify seasonal changes in green biomass. Sagebrush biomass was estimated using both a voxel and a 3-D convex hull approach applied to TLS point cloud data. The 3-D convex hull model estimated total and green biomass more accurately (R2 = 0.92 and R2 = 0.83, respectively) than the voxel-based method (R2 = 0.86 and R2 = 0.73, respectively). Seasonal differences in TLS-predicted green biomass were detected at two of the sites (p < 0.001 and p = 0.029), elucidating the amount of ephemeral leaf loss in the face of summer drought. The methods presented herein are directly transferable to other dryland shrubs, and implementation of the convex hull model with similar sagebrush species is straightforward.

  18. In situ fluorescence labelling of jasmonic acid binding sites in plant tissues with cadmium-free quantum dots.

    PubMed

    Liao, Qiumei; Yu, Ying; Cao, Yujuan; Lin, Bixia; Wei, Jingjing

    2015-02-01

    The fluorescence labelling of plant hormone binding sites is an important analytical technique in research on the molecular mechanisms of plant hormone activities. The authors synthesised a jasmonic acid (JA)-conjugated ZnS:Mn quantum dot (QD) probe, with a cubic structure and average hydrodynamic sizes of about 17.0 nm. The maximum fluorescence emission of the probe was recorded at about 585 nm. The probe was used for fluorescence labelling of JA binding sites in mung bean seedling tissues. Analysis revealed that the probe exhibited high selectivity to JA binding sites and good performance in eliminating interference from background fluorescence in plant tissues. In addition, the probe did not exhibit any apparent biotoxicity, and is much more suitable than probes constructed from CdTe QDs for the analysis of biological samples. PMID:25650324

  19. Studies on the medicinal properties of Solanum chrysotrichum in tissue culture: I. Callus formation and plant induction from axillary buds.

    PubMed

    Villarreal, M L; Muñoz, J

    1991-01-01

    A tissue culture method is described for micropropagation and callus formation from Solanum chrysotricum axillary bud explants in Murashige and Skoog's (MS) medium, supplemented with various growth regulators. Induction of rooted plants were initiated only when indol-3 acetic acid (IAA) was present as an auxin in combination with either of two cytokinins: kinetin (KN) or benzyladenine (BA); however, the combination of IAA (0.1 mg.lt.-1) + BA (0.2 mg.lt.-1) was found to be best suited for morphogenesis purposes. Alternatively, callus tissue formation was influenced in presence of naphthalene acetic acid; which in combination with kinetin (NAA 0.1 mg.lt.-1 + KN 0.2 mg.lt.-1) exhibit the best response studied. The plant material obtained by this procedure is proposed for pharmacological and chemical studies of this important antimycotic plant remedy. PMID:1819987

  20. Plants as biofactories: glyphosate-induced production of shikimic acid and phenolic antioxidants in wounded carrot tissue.

    PubMed

    Becerra-Moreno, Alejandro; Benavides, Jorge; Cisneros-Zevallos, Luis; Jacobo-Velázquez, Daniel A

    2012-11-14

    The use of plants to produce chemical compounds with pharmaceutical and nutraceutical applications has intensified in recent years. In this regard, genetic engineering is the most commonly used tool to generate crop lines with enhanced concentrations of desirable chemicals. However, growing genetically modified plants is still limited because they are perceived as potential biological hazards that can create an ecological imbalance. The application of postharvest abiotic stresses on plants induces the accumulation of secondary metabolites and thus can be used as an alternative to genetic modification. The present project evaluated the feasibility of producing shikimic acid (SA) and phenolic compounds (PC) in wounded carrots ( Daucus carota ) treated with glyphosate. The spray application of a concentrated glyphosate solution on wounded carrot tissue increased the concentrations of SA and chlorogenic acid by ∼1735 and ∼5700%, respectively. The results presented herein demonstrate the potential of stressed carrot tissue as a biofactory of SA and PC. PMID:23101679

  1. Direct DNA extraction method of an obligate parasitic fungus from infected plant tissue.

    PubMed

    Liu, L; Wang, C L; Peng, W Y; Yang, J; Lan, M Q; Zhang, B; Li, J B; Zhu, Y Y; Li, C Y

    2015-01-01

    Powdery mildew and rust fungi are obligate parasites that cannot live without host organisms. They are difficult to culture in synthetic medium in the laboratory. Genomic DNA extraction is one of the basic molecular techniques used to study the genetic structure of populations. In this study, 2 different DNA extraction methods, Chelex-100 and cetyltrimethylammonium bromide (CTAB), were used to extract DNA from euonymus powdery mildew and Puccinia striiformis f. sp Tritici. Polymerase chain reaction was carried out with a race-specific-marker rDNA-internal transcribed spacer sequence. Both DNA extraction methods were compared and analyzed. The results showed that both Chelex-100 and CTAB were effective for extracting genomic DNA from infected plant tissue. However, less DNA was required for the Chelex-100 method than for the CTAB method, and the Chelex-100 method involved fewer steps, was simpler and safer, and did not require organic solvents compared to the CTAB method. DNA quality was evaluated by polymerase chain reaction, and the results showed that genomic DNA extracted using the Chelex-100 method was better than that using CTAB method, and was sufficient for studying the genetic structure of population. PMID:26782502

  2. Infrared microspectroscopic imaging of plant tissues: spectral visualization of Triticum aestivum kernel and Arabidopsis leaf microstructure

    PubMed Central

    Warren, Frederick J; Perston, Benjamin B; Galindez-Najera, Silvia P; Edwards, Cathrina H; Powell, Prudence O; Mandalari, Giusy; Campbell, Grant M; Butterworth, Peter J; Ellis, Peter R

    2015-01-01

    Infrared microspectroscopy is a tool with potential for studies of the microstructure, chemical composition and functionality of plants at a subcellular level. Here we present the use of high-resolution bench top-based infrared microspectroscopy to investigate the microstructure of Triticum aestivum L. (wheat) kernels and Arabidopsis leaves. Images of isolated wheat kernel tissues and whole wheat kernels following hydrothermal processing and simulated gastric and duodenal digestion were generated, as well as images of Arabidopsis leaves at different points during a diurnal cycle. Individual cells and cell walls were resolved, and large structures within cells, such as starch granules and protein bodies, were clearly identified. Contrast was provided by converting the hyperspectral image cubes into false-colour images using either principal component analysis (PCA) overlays or by correlation analysis. The unsupervised PCA approach provided a clear view of the sample microstructure, whereas the correlation analysis was used to confirm the identity of different anatomical structures using the spectra from isolated components. It was then demonstrated that gelatinized and native starch within cells could be distinguished, and that the loss of starch during wheat digestion could be observed, as well as the accumulation of starch in leaves during a diurnal period. PMID:26400058

  3. Tissue Culture Study of The Medicinal Plant Leek (Allium Ampeloprasum L)

    PubMed Central

    Monemi, Mohammad Bagher; Kazemitabar, S. Kamal; Bakhshee Khaniki, Gholamreza; Yasari, Esmaeil; Sohrevardi, Firouzeh; Pourbagher, Roghayeh

    2014-01-01

    Persian shallot, also called leek (Allium ampeloprasum), is a monocotyledon plant of the lily family (Liliaceae). It belongs to the genus Allium, has a characteristic taste and morphological features, making it to be considered as one of the popular herbal medicine. This research was conducted with the purpose of obtaining optimal conditions for tissue culture of Persian shallot and comparing its active ingredient production in vitro versus in vivo. In this study, the auxin 2, 4–D and benzyl aminopurine- 6 (BAP) hormones, each at two concentrations (0.5 and 0.1 mg/ L) and Kin at 0.5 mg/ L were used in the format of a randomized complete block design in three replications. Results showed that the best culture media for callus formation for leaf and seed explants were the MS cultures with the hormonal compositions (0.5 mg/ L of 2, 4– D, 0.1 mg/ L of BAP) and (0.5 mg/ L of Kin and 0.1 mg/ L of 2, 4– D). Identification of the chemical composition of the essential oils, extracted either from leek callus or leaf was carried out using GC mass analysis. Twenty one compounds were detected in the GC mass spectra, seven of which constitutv about 51.5% of the total amount of compounds present in the essential oils were identified. Our data demonstrate that the leek essential oil constituents as well as callus formation can be affected by culture medium condition. PMID:25035862

  4. Infrared microspectroscopic imaging of plant tissues: spectral visualization of Triticum aestivum kernel and Arabidopsis leaf microstructure.

    PubMed

    Warren, Frederick J; Perston, Benjamin B; Galindez-Najera, Silvia P; Edwards, Cathrina H; Powell, Prudence O; Mandalari, Giusy; Campbell, Grant M; Butterworth, Peter J; Ellis, Peter R

    2015-11-01

    Infrared microspectroscopy is a tool with potential for studies of the microstructure, chemical composition and functionality of plants at a subcellular level. Here we present the use of high-resolution bench top-based infrared microspectroscopy to investigate the microstructure of Triticum aestivum L. (wheat) kernels and Arabidopsis leaves. Images of isolated wheat kernel tissues and whole wheat kernels following hydrothermal processing and simulated gastric and duodenal digestion were generated, as well as images of Arabidopsis leaves at different points during a diurnal cycle. Individual cells and cell walls were resolved, and large structures within cells, such as starch granules and protein bodies, were clearly identified. Contrast was provided by converting the hyperspectral image cubes into false-colour images using either principal component analysis (PCA) overlays or by correlation analysis. The unsupervised PCA approach provided a clear view of the sample microstructure, whereas the correlation analysis was used to confirm the identity of different anatomical structures using the spectra from isolated components. It was then demonstrated that gelatinized and native starch within cells could be distinguished, and that the loss of starch during wheat digestion could be observed, as well as the accumulation of starch in leaves during a diurnal period. PMID:26400058

  5. Tissue culture study of the medicinal plant leek (allium ampeloprasum L).

    PubMed

    Monemi, Mohammad Bagher; Kazemitabar, S Kamal; Bakhshee Khaniki, Gholamreza; Yasari, Esmaeil; Sohrevardi, Firouzeh; Pourbagher, Roghayeh

    2014-01-01

    Persian shallot, also called leek (Allium ampeloprasum), is a monocotyledon plant of the lily family (Liliaceae). It belongs to the genus Allium, has a characteristic taste and morphological features, making it to be considered as one of the popular herbal medicine. This research was conducted with the purpose of obtaining optimal conditions for tissue culture of Persian shallot and comparing its active ingredient production in vitro versus in vivo. In this study, the auxin 2, 4-D and benzyl aminopurine- 6 (BAP) hormones, each at two concentrations (0.5 and 0.1 mg/ L) and Kin at 0.5 mg/ L were used in the format of a randomized complete block design in three replications. Results showed that the best culture media for callus formation for leaf and seed explants were the MS cultures with the hormonal compositions (0.5 mg/ L of 2, 4- D, 0.1 mg/ L of BAP) and (0.5 mg/ L of Kin and 0.1 mg/ L of 2, 4- D). Identification of the chemical composition of the essential oils, extracted either from leek callus or leaf was carried out using GC mass analysis. Twenty one compounds were detected in the GC mass spectra, seven of which constitutv about 51.5% of the total amount of compounds present in the essential oils were identified. Our data demonstrate that the leek essential oil constituents as well as callus formation can be affected by culture medium condition. PMID:25035862

  6. An UPLC-MS/MS method for highly sensitive high-throughput analysis of phytohormones in plant tissues

    PubMed Central

    2012-01-01

    Background Phytohormones are the key metabolites participating in the regulation of multiple functions of plant organism. Among them, jasmonates, as well as abscisic and salicylic acids are responsible for triggering and modulating plant reactions targeted against pathogens and herbivores, as well as resistance to abiotic stress (drought, UV-irradiation and mechanical wounding). These factors induce dramatic changes in phytohormone biosynthesis and transport leading to rapid local and systemic stress responses. Understanding of underlying mechanisms is of principle interest for scientists working in various areas of plant biology. However, highly sensitive, precise and high-throughput methods for quantification of these phytohormones in small samples of plant tissues are still missing. Results Here we present an LC-MS/MS method for fast and highly sensitive determination of jasmonates, abscisic and salicylic acids. A single-step sample preparation procedure based on mixed-mode solid phase extraction was efficiently combined with essential improvements in mobile phase composition yielding higher efficiency of chromatographic separation and MS-sensitivity. This strategy resulted in dramatic increase in overall sensitivity, allowing successful determination of phytohormones in small (less than 50 mg of fresh weight) tissue samples. The method was completely validated in terms of analyte recovery, sensitivity, linearity and precision. Additionally, it was cross-validated with a well-established GC-MS-based procedure and its applicability to a variety of plant species and organs was verified. Conclusion The method can be applied for the analyses of target phytohormones in small tissue samples obtained from any plant species and/or plant part relying on any commercially available (even less sensitive) tandem mass spectrometry instrumentation. PMID:23173950

  7. A phloem-limited fijivirus induces the formation of neoplastic phloem tissues that house virus multiplication in the host plant.

    PubMed

    Shen, Jiangfeng; Chen, Xian; Chen, Jianping; Sun, Liying

    2016-01-01

    A number of phloem-limited viruses induce the development of tumours (enations) in the veins of host plants, but the relevance of tumour induction to the life cycle of those viruses is unclear. In this study, we performed molecular and structural analyses of tumours induced by rice black-streaked dwarf virus (RBSDV, genus Fijivirus) infection in maize plants. The transcript level of the maize cdc2 gene, which regulates the cell cycle, was highly elevated in tumour tissues. Two-dimensional electrophoresis identified 25 cellular proteins with altered accumulation in the tumour tissues. These proteins are involved in various metabolic pathways, including photosynthesis, redox, energy pathways and amino acid synthesis. Histological analysis indicated that the tumours predominantly originated from hyperplastic growth of phloem, but those neoplastic tissues have irregular structures and cell arrangements. Immunodetection assays and electron microscopy observations indicated that in the shoots, RBSDV is confined to phloem and tumour regions and that virus multiplication actively occurs in the tumour tissue, as indicated by the high accumulation of non-structural proteins and formation of viroplasms in the tumour cells. Thus, the induction of tumours by RBSDV infection provides a larger environment that is favourable for virus propagation in the host plant. PMID:27432466

  8. A phloem-limited fijivirus induces the formation of neoplastic phloem tissues that house virus multiplication in the host plant

    PubMed Central

    Shen, Jiangfeng; Chen, Xian; Chen, Jianping; Sun, Liying

    2016-01-01

    A number of phloem-limited viruses induce the development of tumours (enations) in the veins of host plants, but the relevance of tumour induction to the life cycle of those viruses is unclear. In this study, we performed molecular and structural analyses of tumours induced by rice black-streaked dwarf virus (RBSDV, genus Fijivirus) infection in maize plants. The transcript level of the maize cdc2 gene, which regulates the cell cycle, was highly elevated in tumour tissues. Two-dimensional electrophoresis identified 25 cellular proteins with altered accumulation in the tumour tissues. These proteins are involved in various metabolic pathways, including photosynthesis, redox, energy pathways and amino acid synthesis. Histological analysis indicated that the tumours predominantly originated from hyperplastic growth of phloem, but those neoplastic tissues have irregular structures and cell arrangements. Immunodetection assays and electron microscopy observations indicated that in the shoots, RBSDV is confined to phloem and tumour regions and that virus multiplication actively occurs in the tumour tissue, as indicated by the high accumulation of non-structural proteins and formation of viroplasms in the tumour cells. Thus, the induction of tumours by RBSDV infection provides a larger environment that is favourable for virus propagation in the host plant. PMID:27432466

  9. Aboveground allometric models for freeze-affected black mangroves (Avicennia germinans): equations for a climate sensitive mangrove-marsh ecotone.

    PubMed

    Osland, Michael J; Day, Richard H; Larriviere, Jack C; From, Andrew S

    2014-01-01

    Across the globe, species distributions are changing in response to climate change and land use change. In parts of the southeastern United States, climate change is expected to result in the poleward range expansion of black mangroves (Avicennia germinans) at the expense of some salt marsh vegetation. The morphology of A. germinans at its northern range limit is more shrub-like than in tropical climes in part due to the aboveground structural damage and vigorous multi-stem regrowth triggered by extreme winter temperatures. In this study, we developed aboveground allometric equations for freeze-affected black mangroves which can be used to quantify: (1) total aboveground biomass; (2) leaf biomass; (3) stem plus branch biomass; and (4) leaf area. Plant volume (i.e., a combination of crown area and plant height) was selected as the optimal predictor of the four response variables. We expect that our simple measurements and equations can be adapted for use in other mangrove ecosystems located in abiotic settings that result in mangrove individuals with dwarf or shrub-like morphologies including oligotrophic and arid environments. Many important ecological functions and services are affected by changes in coastal wetland plant community structure and productivity including carbon storage, nutrient cycling, coastal protection, recreation, fish and avian habitat, and ecosystem response to sea level rise and extreme climatic events. Coastal scientists in the southeastern United States can use the identified allometric equations, in combination with easily obtained and non-destructive plant volume measurements, to better quantify and monitor ecological change within the dynamic, climate sensitive, and highly-productive mangrove-marsh ecotone. PMID:24971938

  10. Aboveground Allometric Models for Freeze-Affected Black Mangroves (Avicennia germinans): Equations for a Climate Sensitive Mangrove-Marsh Ecotone

    PubMed Central

    Osland, Michael J.; Day, Richard H.; Larriviere, Jack C.; From, Andrew S.

    2014-01-01

    Across the globe, species distributions are changing in response to climate change and land use change. In parts of the southeastern United States, climate change is expected to result in the poleward range expansion of black mangroves (Avicennia germinans) at the expense of some salt marsh vegetation. The morphology of A. germinans at its northern range limit is more shrub-like than in tropical climes in part due to the aboveground structural damage and vigorous multi-stem regrowth triggered by extreme winter temperatures. In this study, we developed aboveground allometric equations for freeze-affected black mangroves which can be used to quantify: (1) total aboveground biomass; (2) leaf biomass; (3) stem plus branch biomass; and (4) leaf area. Plant volume (i.e., a combination of crown area and plant height) was selected as the optimal predictor of the four response variables. We expect that our simple measurements and equations can be adapted for use in other mangrove ecosystems located in abiotic settings that result in mangrove individuals with dwarf or shrub-like morphologies including oligotrophic and arid environments. Many important ecological functions and services are affected by changes in coastal wetland plant community structure and productivity including carbon storage, nutrient cycling, coastal protection, recreation, fish and avian habitat, and ecosystem response to sea level rise and extreme climatic events. Coastal scientists in the southeastern United States can use the identified allometric equations, in combination with easily obtained and non-destructive plant volume measurements, to better quantify and monitor ecological change within the dynamic, climate sensitive, and highly-productive mangrove-marsh ecotone. PMID:24971938

  11. Aboveground allometric models for freeze-affected black mangroves (Avicennia germinans): equations for a climate sensitive mangrove-marsh ecotone

    USGS Publications Warehouse

    Osland, Michael J.; Day, Richard H.; Larriviere, Jack C.; From, Andrew S.

    2014-01-01

    Across the globe, species distributions are changing in response to climate change and land use change. In parts of the southeastern United States, climate change is expected to result in the poleward range expansion of black mangroves (Avicennia germinans) at the expense of some salt marsh vegetation. The morphology of A. germinans at its northern range limit is more shrub-like than in tropical climes in part due to the aboveground structural damage and vigorous multi-stem regrowth triggered by extreme winter temperatures. In this study, we developed aboveground allometric equations for freeze-affected black mangroves which can be used to quantify: (1) total aboveground biomass; (2) leaf biomass; (3) stem plus branch biomass; and (4) leaf area. Plant volume (i.e., a combination of crown area and plant height) was selected as the optimal predictor of the four response variables. We expect that our simple measurements and equations can be adapted for use in other mangrove ecosystems located in abiotic settings that result in mangrove individuals with dwarf or shrub-like morphologies including oligotrophic and arid environments. Many important ecological functions and services are affected by changes in coastal wetland plant community structure and productivity including carbon storage, nutrient cycling, coastal protection, recreation, fish and avian habitat, and ecosystem response to sea level rise and extreme climatic events. Coastal scientists in the southeastern United States can use the identified allometric equations, in combination with easily obtained and non-destructive plant volume measurements, to better quantify and monitor ecological change within the dynamic, climate sensitive, and highly-productive mangrove-marsh ecotone.

  12. A Rapid Technique for the Estimation of Polynucleotide Adenylyltransferase and Ribonucleic Acid Polymerase in Plant Tissues 1

    PubMed Central

    Walter, Trevor J.; Mans, Rusty J.

    1975-01-01

    Nucleic acid-dependent polynucleotide adenylytransferase (EC 2.7.7.19) and ribonucleic acid polymerase (EC 2.7.7.6) have been partially purified from maize tissues (Zea mays L.) utilizing ammonium sulfate precipitation and batch diethylaminoethylcellulose chromatography. The technique is applicable to the simultaneous processing of up to eight samples of plant tissue and affords a rapid and reproducible means of assaying these two enzymes from small quantities of kernels or seedlings. The kinetic characteristics of the partially purified enzymes resemble those from more extensively purified preparations. PMID:16659402

  13. Ricinosomes: an organelle for developmentally regulated programmed cell death in senescing plant tissues

    NASA Astrophysics Data System (ADS)

    Gietl, C.; Schmid, M.

    2001-02-01

    This review describes aspects of programmed cell death (PCD). Present research maps the enzymes involved and explores the signal transduction pathways involved in their synthesis. A special organelle (the ricinosome) has been discovered in the senescing endosperm of germinating castor beans (Ricinus communis) that develops at the beginning of PCD and delivers large amounts of a papain-type cysteine endopeptidase (CysEP) in the final stages of cellular disintegration. Castor beans store oil and proteins in a living endosperm surrounding the cotyledons. These stores are mobilized during germination and transferred into the cotyledons. PCD is initiated after this transfer is complete. The CysEP is synthesized in the lumen of the endoplasmic reticulum (ER) where it is retained by its C-terminal KDEL peptide as a rather inactive pro-enzyme. Large number of ricinosomes bud from the ER at the same time as the nuclear DNA is characteristically fragmented during PCD. The mitochondria, glyoxysomes and ribosomes are degraded in autophagic vacuoles, while the endopeptidase is activated by removal of the propeptide and the KDEL tail and enters the cytosol. The endosperm dries and detaches from the cotyledons. A homologous KDEL-tailed cysteine endopeptidase has been found in several senescing tissues; it has been localized in ricinosomes of withering day-lily petals and dying seed coats. Three genes for a KDEL-tailed cysteine endopeptidase have been identified in Arabidopsis. One is expressed in senescing ovules, the second in the vascular vessels and the third in maturing siliques. These genes open the way to exploring PCD in plants.

  14. Molecular Dissection of The Cellular Mechanisms Involved In Nickel Hyperaccumulation in Plants

    SciTech Connect

    David E. Salt

    2002-04-08

    Hyperaccumulator plant species are able to accumulate between 1-5% of their biomass as metal. However, these plants are often small, slow growing, and do not produce a high biomass. Phytoextraction, a cost-effective, in situ, plant based approach to soil remediation takes advantage of the remarkable ability of hyperaccumulating plants to concentrate metals from the soil and accumulate them in their harvestable, above-ground tissues. However, to make use of the valuable genetic resources identified in metal hyperaccumulating species, it will be necessary to transfer this material to high biomass rapidly growing crop plants. These plants would then be ideally suited to the phytoremediation process, having the ability to produce large amount of metal-rich plant biomass for rapid harvest and soil cleanup. Although progress is being made in understanding the genetic basis of metal hyperaccumulation a more complete understanding will be necessary before we can take full advantage of the genetic potential of these plants.

  15. Human and environmental controls over aboveground carbon storage in Madagascar

    PubMed Central

    2012-01-01

    Background Accurate, high-resolution mapping of aboveground carbon density (ACD, Mg C ha-1) could provide insight into human and environmental controls over ecosystem state and functioning, and could support conservation and climate policy development. However, mapping ACD has proven challenging, particularly in spatially complex regions harboring a mosaic of land use activities, or in remote montane areas that are difficult to access and poorly understood ecologically. Using a combination of field measurements, airborne Light Detection and Ranging (LiDAR) and satellite data, we present the first large-scale, high-resolution estimates of aboveground carbon stocks in Madagascar. Results We found that elevation and the fraction of photosynthetic vegetation (PV) cover, analyzed throughout forests of widely varying structure and condition, account for 27-67% of the spatial variation in ACD. This finding facilitated spatial extrapolation of LiDAR-based carbon estimates to a total of 2,372,680 ha using satellite data. Remote, humid sub-montane forests harbored the highest carbon densities, while ACD was suppressed in dry spiny forests and in montane humid ecosystems, as well as in most lowland areas with heightened human activity. Independent of human activity, aboveground carbon stocks were subject to strong physiographic controls expressed through variation in tropical forest canopy structure measured using airborne LiDAR. Conclusions High-resolution mapping of carbon stocks is possible in remote regions, with or without human activity, and thus carbon monitoring can be brought to highly endangered Malagasy forests as a climate-change mitigation and biological conservation strategy. PMID:22289685

  16. Growth of plant tissue cultures in simulated lunar soil: Implications for a lunar base CELSS (Controlled Ecological Life Support System)

    NASA Technical Reports Server (NTRS)

    Venketeswaran, S.

    1988-01-01

    Experiments were carried out on plant tissue cultures, seed germination, seedling development and plants grown on Simulated Lunar Soil to evaluate the potential of future development of lunar based agriculture. The studies done to determine the effect of the placement of SLS on tissue cultures showed no adverse effect of SLS on tissue cultures. Although statistically insignificant, SLS in suspension showed a comparatively higher growth rate. Observations indicate the SLS, itself cannot support calli growth but was able to show a positive effect on growth rate of calli when supplemented with MS salts. This positive effect related to nutritive value of the SLS was found to have improved at high pH levels, than at the recommended low pH levels for standard media. Results from seed germination indicated that there is neither inhibitory, toxicity nor stimulatory effect of SLS, even though SLS contains high amounts of aluminum compounds compared to earth soil. Analysis of seeding development and growth data showed significant reduction in growth rate indicating that, SLS was a poor growth medium for plant life. This was confirmed by the studies done with embryos and direct plant growth on SLS. Further observations attributed this poor quality of SLS is due to it's lack of essential mineral elements needed for plant growth. By changing the pH of the soil, to more basic conditions, the quality of SLS for plant growth could be improved up to a significant level. Also it was found that the quality of SLS could be improved by almost twice, by external supply of major mineral elements, directly to SLS.

  17. Selenium concentrations in water and plant tissues of a newly formed arid wetland in Las Vegas, Nevada.

    PubMed

    Pollard, James; Cizdziel, James; Stave, Krystyna; Reid, Michelle

    2007-12-01

    There is concern that elevated levels of selenium found in the source water of a newly formed wetland park in Las Vegas, Nevada, may have detrimental effects on local wildlife. In this study, we collected and analyzed water samples monthly for a three year period from the inflow and outflow of the system. We also gathered dominant aquatic plants and selected terrestrial plants and analyzed the water and plant tissues (root, shoot, leaf and flower) for selenium by high resolution Inductively Coupled Plasma Mass Spectrometer. Except for storm events and the introduction of an alternative low selenium content source water during summer low-flow conditions, selenium in the water was relatively stable. The concentration in the outflow tended to be slightly lower than the inflow. Concentrations of selenium in the dominant plant taxa in this wetlands were typical of ecosystems in the western United States and varied by taxa, tissue type, localized conditions (e.g., contact with selenium-laden water), and to a lesser extent, seasons. Selenium in the aquatic plant spiny naiad (Najas marina) was relatively high and may pose an ecological risk to wildlife during the late spring and summer. Additional work is underway investigating aquatic food chain accumulations of selenium as well as mass balance of selenium in the system. PMID:17394092

  18. Manipulation of lignin composition in plants using a tissue-specific promoter

    DOEpatents

    Chapple, Clinton C. S.

    2003-08-26

    The present invention relates to methods and materials in the field of molecular biology, the manipulation of the phenylpropanoid pathway and the regulation of proteins synthesis through plant genetic engineering. More particularly, the invention relates to the introduction of a foreign nucleotide sequence into a plant genome, wherein the introduction of the nucleotide sequence effects an increase in the syringyl content of the plant's lignin. In one specific aspect, the invention relates to methods for modifying the plant lignin composition in a plant cell by the introduction there into of a foreign nucleotide sequence comprising at issue specific plant promoter sequence and a sequence encoding an active ferulate-5-hydroxylase (F5H) enzyme. Plant transformants harboring an inventive promoter-F5H construct demonstrate increased levels of syringyl monomer residues in their lignin, rendering the polymer more readily delignified and, thereby, rendering the plant more readily pulped or digested.

  19. Inhibition of phenylpropanoid biosynthesis in Artemisia annua L.: a novel approach to reduce oxidative browning in plant tissue culture.

    PubMed

    Jones, Andrew Maxwell Phineas; Saxena, Praveen Kumar

    2013-01-01

    Oxidative browning is a common and often severe problem in plant tissue culture systems caused by the accumulation and oxidation of phenolic compounds. The current study was conducted to investigate a novel preventative approach to address this problem by inhibiting the activity of the phenylalanine ammonia lyase enzyme (PAL), thereby reducing the biosynthesis of phenolic compounds. This was accomplished by incorporating 2-aminoindane-2-phosphonic acid (AIP), a competitive PAL inhibitor, into culture media of Artemisia annua as a model system. Addition of AIP into culture media resulted in significant reductions in visual tissue browning, a reduction in total phenol content, as well as absorbance and autoflourescence of tissue extracts. Reduced tissue browning was accompanied with a significant increase in growth on cytokinin based medium. Microscopic observations demonstrated that phenolic compounds accumulated in discrete cells and that these cells were more prevalent in brown tissue. These cells were highly plasmolyzed and often ruptured during examination, demonstrating a mechanism in which phenolics are released into media in this system. These data indicate that inhibiting phenylpropanoid biosynthesis with AIP is an effective approach to reduce tissue browning in A. annua. Additional experiments with Ulmus americana and Acer saccharum indicate this approach is effective in many species and it could have a wide application in systems where oxidative browning restricts the development of biotechnologies. PMID:24116165

  20. Inhibition of Phenylpropanoid Biosynthesis in Artemisia annua L.: A Novel Approach to Reduce Oxidative Browning in Plant Tissue Culture

    PubMed Central

    Jones, Andrew Maxwell Phineas; Saxena, Praveen Kumar

    2013-01-01

    Oxidative browning is a common and often severe problem in plant tissue culture systems caused by the accumulation and oxidation of phenolic compounds. The current study was conducted to investigate a novel preventative approach to address this problem by inhibiting the activity of the phenylalanine ammonia lyase enzyme (PAL), thereby reducing the biosynthesis of phenolic compounds. This was accomplished by incorporating 2-aminoindane-2-phosphonic acid (AIP), a competitive PAL inhibitor, into culture media of Artemisia annua as a model system. Addition of AIP into culture media resulted in significant reductions in visual tissue browning, a reduction in total phenol content, as well as absorbance and autoflourescence of tissue extracts. Reduced tissue browning was accompanied with a significant increase in growth on cytokinin based medium. Microscopic observations demonstrated that phenolic compounds accumulated in discrete cells and that these cells were more prevalent in brown tissue. These cells were highly plasmolyzed and often ruptured during examination, demonstrating a mechanism in which phenolics are released into media in this system. These data indicate that inhibiting phenylpropanoid biosynthesis with AIP is an effective approach to reduce tissue browning in A. annua. Additional experiments with Ulmus americana and Acer saccharum indicate this approach is effective in many species and it could have a wide application in systems where oxidative browning restricts the development of biotechnologies. PMID:24116165

  1. Implications for pesticide delivery and insecticide selection using chemical analysis of plant tissue and efficacy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Applications studies have demonstrated the difficulty in uniformly delivering pesticide across and through plant canopies. Systemic insecticides are often used for management of insect pests because their movement through a plant can provide protection in difficult to treat parts of plants. Insect...

  2. Closure Report for Corrective Action Unit 134: Aboveground Storage Tanks, Nevada Test Site, Nevada

    SciTech Connect

    NSTec Environmental Restoration

    2009-06-30

    Corrective Action Unit (CAU) 134 is identified in the Federal Facility Agreement and Consent Order (FFACO) as “Aboveground Storage Tanks” and consists of the following four Corrective Action Sites (CASs), located in Areas 3, 15, and 29 of the Nevada Test Site: · CAS 03-01-03, Aboveground Storage Tank · CAS 03-01-04, Tank · CAS 15-01-05, Aboveground Storage Tank · CAS 29-01-01, Hydrocarbon Stain

  3. The Effect of Plant Tissue and Vaccine Formulation on the Oral Immunogenicity of a Model Plant-Made Antigen in Sheep

    PubMed Central

    Pelosi, Assunta; Piedrafita, David; De Guzman, Giorgio; Shepherd, Robert; Hamill, John D.; Meeusen, Els; Walmsley, Amanda M.

    2012-01-01

    Antigen-specific antibody responses against a model antigen (the B subunit of the heat labile toxin of enterotoxigenic Escherichia coli, LTB) were studied in sheep following oral immunisation with plant-made and delivered vaccines. Delivery from a root-based vehicle resulted in antigen-specific immune responses in mucosal secretions of the abomasum and small intestine and mesenteric lymph nodes. Immune responses from the corresponding leaf-based vaccine were more robust and included stimulation of antigen-specific antibodies in mucosal secretions of the abomasum. These findings suggest that oral delivery of a plant bioencapsulated antigen can survive passage through the rumen to elicit mucosal and systemic immune responses in sheep. Moreover, the plant tissue used as the vaccine delivery vehicle affects the magnitude of these responses. PMID:23285224

  4. Fate of polycyclic aromatic hydrocarbons in plant-soil systems: Plant responses to a chemical stress in the root zone

    SciTech Connect

    Hoylman, A.M.

    1993-01-01

    Plant uptake and translocation of polycyclic aromatic hydrocarbons (PAHs) from soil was investigated to explore plant-microbial interactions in response to a chemical stress in the root zone. Plant uptake of individual PAHs was examined under laboratory conditions which maximized root exposure. White sweetclover, Melilotus alba, was grown in soils dosed with [sup 14]C-naphthalene, -phenanthrene, -pyrene, and -fluoranthene. The highest [sup 14]C concentrations were associated with roots, with decreasing concentrations observed in stems and leaves; however, the greatest percentage of recoverable [sup 14]C remained in the soil ([ge]86%) for all four PAHs. No evidence of bioaccumulation of the individual PAHs was found in M. alba over a 5-day exposure period. Root uptake and translocation of PAHs from soil to aboveground plant tissues proved to be a limited mechanism for PAH transport into terrestrial food chains. However, root surface sorption of PAHs may be important for plants in soils containing elevated concentrations of PAHs. Consequently, the root-soil interface may be important for plant-microbial interactions in response to a chemical stress. [sup 14]CO[sub 2] pulse-labeling studies provide evidence of a shift in [sup 14]C-allocation from aboveground tissue to the root zone when plants were exposed simultaneously to phenanthrene in soil. In addition, soil respiration and heterotrophic plate counts of rhizosphere microorganisms increased in plants exposed to phenanthrene as compared to controls. This study demonstrates the importance of the root-soil interface for plants growing in PAH contaminated soil and provides supportive evidence for a plant-microbial defense response to chemical toxicants in the root zone. Lipophilic toxicants in soils may reach high concentrations in the root zone, but rhizosphere microbial communities under the influence of the plant may reduce the amount of the compound that is actually taken up by the root.

  5. Chemical defenses promote persistence of the aquatic plant Micranthemum umbrosum.

    PubMed

    Parker, John D; Collins, Dwight O; Kubanek, Julia; Sullards, M Cameron; Bostwick, David; Hay, Mark E

    2006-04-01

    Five of the most common macrophytes from an aquaculture facility with high densities of the herbivorous Asian grass carp (Ctenopharyngodon idella) were commonly unpalatable to three generalist consumers-grass carp and the native North American crayfishes Procambarus spiculifer and P. acutus. The rooted vascular plant Micranthemum umbrosum comprised 89% of the total aboveground plant biomass and was unpalatable to all three consumers as fresh tissues, as homogenized pellets, and as crude extracts. Bioassay-guided fractionation of the crude extract from M. umbrosum led to four previously known compounds that each deterred feeding by at least one consumer: 3,4,5-trimethoxyallylbenzene (1) and three lignoids: beta-apopicropodophyllin (2); (-)-(3S,4R,6S)-3-(3',4'-methylenedioxy-alpha-hydroxybenzyl)-4-(3'',4''-dimethoxybenzyl)butyrolactone (3); and (-)-hibalactone (4). None of the remaining four macrophytes produced a chemically deterrent extract. A 16-mo manipulative experiment showed that the aboveground biomass of M. umbrosum was unchanged when consumers were absent, but the biomass of Ludwigia repens, a plant that grass carp preferentially consumed over M. umbrosum, increased over 300-fold. Thus, selective feeding by grass carp effectively eliminates most palatable plants from this community and promotes the persistence of the chemically defended M. umbrosum, suggesting that plant defenses play critical yet understudied roles in the structure of freshwater plant communities. PMID:16586032

  6. Rhizospheric Bacterial Strain Brevibacterium casei MH8a Colonizes Plant Tissues and Enhances Cd, Zn, Cu Phytoextraction by White Mustard

    PubMed Central

    Płociniczak, Tomasz; Sinkkonen, Aki; Romantschuk, Martin; Sułowicz, Sławomir; Piotrowska-Seget, Zofia

    2016-01-01

    Environmental pollution by heavy metals has become a serious problem in the world. Phytoextraction, which is one of the plant-based technologies, has attracted the most attention for the bioremediation of soils polluted with these contaminants. The aim of this study was to determine whether the multiple-tolerant bacterium, Brevibacterium casei MH8a isolated from the heavy metal-contaminated rhizosphere soil of Sinapis alba L., is able to promote plant growth and enhance Cd, Zn, and Cu uptake by white mustard under laboratory conditions. Additionally, the ability of the rifampicin-resistant spontaneous mutant of MH8a to colonize plant tissues and its mechanisms of plant growth promotion were also examined. In order to assess the ecological consequences of bioaugmentation on autochthonous bacteria, the phospholipid fatty acid (PLFA) analysis was used. The MH8a strain exhibited the ability to produce ammonia, 1-amino-cyclopropane-1-carboxylic acid deaminase, indole 3-acetic acid and HCN but was not able to solubilize inorganic phosphate and produce siderophores. Introduction of MH8a into soil significantly increased S. alba biomass and the accumulation of Cd (208%), Zn (86%), and Cu (39%) in plant shoots in comparison with those grown in non-inoculated soil. Introduced into the soil, MH8a was able to enter the plant and was found in the roots and leaves of inoculated plants thus indicating its endophytic features. PLFA analysis revealed that the MH8a that was introduced into soil had a temporary influence on the structure of the autochthonous bacterial communities. The plant growth-promoting features of the MH8a strain and its ability to enhance the metal uptake by white mustard and its long-term survival in soil as well as its temporary impact on autochthonous microorganisms make the strain a suitable candidate for the promotion of plant growth and the efficiency of phytoextraction. PMID:26909087

  7. Rhizospheric Bacterial Strain Brevibacterium casei MH8a Colonizes Plant Tissues and Enhances Cd, Zn, Cu Phytoextraction by White Mustard.

    PubMed

    Płociniczak, Tomasz; Sinkkonen, Aki; Romantschuk, Martin; Sułowicz, Sławomir; Piotrowska-Seget, Zofia

    2016-01-01

    Environmental pollution by heavy metals has become a serious problem in the world. Phytoextraction, which is one of the plant-based technologies, has attracted the most attention for the bioremediation of soils polluted with these contaminants. The aim of this study was to determine whether the multiple-tolerant bacterium, Brevibacterium casei MH8a isolated from the heavy metal-contaminated rhizosphere soil of Sinapis alba L., is able to promote plant growth and enhance Cd, Zn, and Cu uptake by white mustard under laboratory conditions. Additionally, the ability of the rifampicin-resistant spontaneous mutant of MH8a to colonize plant tissues and its mechanisms of plant growth promotion were also examined. In order to assess the ecological consequences of bioaugmentation on autochthonous bacteria, the phospholipid fatty acid (PLFA) analysis was used. The MH8a strain exhibited the ability to produce ammonia, 1-amino-cyclopropane-1-carboxylic acid deaminase, indole 3-acetic acid and HCN but was not able to solubilize inorganic phosphate and produce siderophores. Introduction of MH8a into soil significantly increased S. alba biomass and the accumulation of Cd (208%), Zn (86%), and Cu (39%) in plant shoots in comparison with those grown in non-inoculated soil. Introduced into the soil, MH8a was able to enter the plant and was found in the roots and leaves of inoculated plants thus indicating its endophytic features. PLFA analysis revealed that the MH8a that was introduced into soil had a temporary influence on the structure of the autochthonous bacterial communities. The plant growth-promoting features of the MH8a strain and its ability to enhance the metal uptake by white mustard and its long-term survival in soil as well as its temporary impact on autochthonous microorganisms make the strain a suitable candidate for the promotion of plant growth and the efficiency of phytoextraction. PMID:26909087

  8. Down-regulation of tissue N:P ratios in terrestrial plants by elevated CO2.

    PubMed

    Deng, Qi; Hui, Dafeng; Luo, Yiqi; Elser, James; Wang, Ying-ping; Loladze, Irakli; Zhang, Quanfa; Dennis, Sam

    2015-12-01

    Increasing atmospheric CO2 concentrations generally alter element stoichiometry in plants. However, a comprehensive evaluation of the elevated CO2 impact on plant nitrogen: phosphorus (N:P) ratios and the underlying mechanism has not been conducted. We synthesized the results from 112 previously published studies using meta-analysis to evaluate the effects of elevated CO2 on the N:P ratio of terrestrial plants and to explore the underlying mechanism based on plant growth and soil P dynamics. Our results show that terrestrial plants grown under elevated CO2 had lower N:P ratios in both above- and belowground biomass across different ecosystem types. The response ratio for plant N:P was negatively correlated with the response ratio for plant growth in croplands and grasslands, and showed a stronger relationship for P than for N. In addition, the CO2-induced down-regulation of plant N:P was accompanied by 19.3% and 4.2% increases in soil phosphatase activity and labile P, respectively, and a 10.1% decrease in total soil P. Our results show that down-regulation of plant N:P under elevated CO2 corresponds with accelerated soil P cycling. These findings should be useful for better understanding of terrestrial plant stoichiometry in response to elevated CO2 and of the underlying mechanisms affecting nutrient dynamics under climate change. PMID:26909440

  9. Down-regulation of tissue N:P ratios in terrestrial plants by elevated CO2

    NASA Astrophysics Data System (ADS)

    Deng, Q.; Hui, D.; Luo, Y.; Elser, J. J.; Wang, Y.; Loladze, I.; Zhang, Q.; Dennis, S.

    2015-12-01

    Increasing atmospheric CO2 concentrations generally alter element stoichiometry in plants. However, a comprehensive evaluation of the elevated CO2 impact on plant nitrogen:phosphorus (N:P) ratios and the underlying mechanism has not been conducted. We synthesized the results from 112 previously published studies using meta-analysis to evaluate the effects of elevated CO2 on the N:P ratio of terrestrial plants and to explore the underlying mechanism based on plant growth and soil P dynamics. Our results show that terrestrial plants grown under elevated CO2 had lower N:P ratios in both above- and below-ground biomass across different ecosystem types. The response ratio for plant N:P was negatively correlated with the response ratio for plant growth in croplands and grasslands, and showed a stronger relationship for P than for N. In addition, the CO2-induced down-regulation of plant N:P was accompanied by 19.3% and 4.2% increases in soil phosphatase activity and labile P, respectively, and a 10.1% decrease in total soil P. Our results show that down-regulation of plant N:P under elevated CO2 corresponds with accelerated soil P cycling. These findings should be useful for better understanding of terrestrial plant stoichiometry in response to elevated CO2 and of the underlying mechanisms affecting nutrient dynamics under climate change.

  10. Carbon Flow and Metabolic Specialization in the Tissue Layers of the Crassulacean Acid Metabolism Plant, Peperomia camptotricha1

    PubMed Central

    Nishio, John N.; Ting, Irwin P.

    1987-01-01

    Leaves of Peperomia camptotricha contain three distinct upper tissue layers and a one-cell thick lower epidermis. Light and dark CO2 fixation rates and the activity of ribulose bisphosphate carboxylase/oxygenase and several C4 enzymes were determined in the three distinct tissue layers. The majority of the C4 enzyme activity and dark CO2 fixation was associated with the spongy mesophyll, including the lower epidermis; and the least activity was found in the median palisade mesophyll. In contrast, the majority of the C3 activity, that is ribulose bisphosphate carboxylase/oxygenase and light CO2 fixation, was located in the palisade mesophyll. In addition, the diurnal flux in titratable acidity was greatest in the spongy mesophyll and lowest in the palisade mesophyll. The spatial separation of the C3 and C4 phases of carbon fixation in P. camptotricha suggests that this Crassulacean acid metabolism plant may have low photorespiratory rates when it exhibits daytime gas exchange (that is, when it is well watered). The results also indicate that this plant may be on an evolutionary path between a true Crassulacean acid metabolism plant and a true C4 plant. PMID:16665487

  11. Short Communication An efficient method for simultaneous extraction of high-quality RNA and DNA from various plant tissues.

    PubMed

    Oliveira, R R; Viana, A J C; Reátegui, A C E; Vincentz, M G A

    2015-01-01

    Determination of gene expression is an important tool to study biological processes and relies on the quality of the extracted RNA. Changes in gene expression profiles may be directly related to mutations in regulatory DNA sequences or alterations in DNA cytosine methylation, which is an epigenetic mark. Correlation of gene expression with DNA sequence or epigenetic mark polymorphism is often desirable; for this, a robust protocol to isolate high-quality RNA and DNA simultaneously from the same sample is required. Although commercial kits and protocols are available, they are mainly optimized for animal tissues and, in general, restricted to RNA or DNA extraction, not both. In the present study, we describe an efficient and accessible method to extract both RNA and DNA simultaneously from the same sample of various plant tissues, using small amounts of starting material. The protocol was efficient in the extraction of high-quality nucleic acids from several Arabidopsis thaliana tissues (e.g., leaf, inflorescence stem, flower, fruit, cotyledon, seedlings, root, and embryo) and from other tissues of non-model plants, such as Avicennia schaueriana (Acanthaceae), Theobroma cacao (Malvaceae), Paspalum notatum (Poaceae), and Sorghum bicolor (Poaceae). The obtained nucleic acids were used as templates for downstream analyses, such as mRNA sequencing, quantitative real time-polymerase chain reaction, bisulfite treatment, and others; the results were comparable to those obtained with commercial kits. We believe that this protocol could be applied to a broad range of plant species, help avoid technical and sampling biases, and facilitate several RNA- and DNA-dependent analyses. PMID:26782533

  12. Costs of jasmonic acid induced defense in aboveground and belowground parts of corn (Zea mays L.).

    PubMed

    Feng, Yuanjiao; Wang, Jianwu; Luo, Shiming; Fan, Huizhi; Jin, Qiong

    2012-08-01

    Costs of jasmonic acid (JA) induced plant defense have gained increasing attention. In this study, JA was applied continuously to the aboveground (AG) or belowground (BG) parts, or AG plus BG parts of corn (Zea mays L.) to investigate whether JA exposure in one part of the plant would affect defense responses in another part, and whether or not JA induced defense would incur allocation costs. The results indicated that continuous JA application to AG parts systemically affected the quantities of defense chemicals in the roots, and vice versa. Quantities of DIMBOA and total amounts of phenolic compounds in leaves or roots generally increased 2 or 4 wk after the JA treatment to different plant parts. In the first 2 wk after application, the increase of defense chemicals in leaves and roots was accompanied by a significant decrease of root length, root surface area, and root biomass. Four weeks after the JA application, however, no such costs for the increase of defense chemicals in leaves and roots were detected. Instead, shoot biomass and root biomass increased. The results suggest that JA as a defense signal can be transferred from AG parts to BG parts of corn, and vice versa. Costs for induced defense elicited by continuous JA application were found in the early 2 wk, while distinct benefits were observed later, i.e., 4 wk after JA treatment. PMID:22744011

  13. Further studies of specimen volume changes during processing for SEM: including some plant tissue.

    PubMed

    Boyde, A; Boyde, S

    1980-01-01

    The dimensions of specimens undergoing preparation for examination in the SEM were measured throughout the preparative sequence or at various important stages. The tissues studied included 15-day mouse embryo limbs (MEL), small blocks of adult mouse liver and brain, and potato tuber. The animal tissues were fixed in 3% glutaraldehyde (GA) in 0.15M cacodylate buffer, and the potatoe tissue in 2% GA in water. The effects of various secondary fixation and other treatments were investigated. The results show that lithium salts cause a reduction in the shrinkage of MEL in 100% ethanol but this effect was not significant in the other tissues investigated, and did not persist in specimens stored after critical point drying (CPD). All CPD specimens were shrunken. However postosmication and treatment with uranyl acetate (UAc) and cetyl pyridinium chloride (CPC) all reduced specimen shrinkage in 100% ethanol and after critical point drying. The volume gains with Os + UAc and Os + CPC are both very significant, but it was found that these larger specimens shrank more on storage. Thus rapid examination in the SEM is recommended. Ethanol and Freon 113 were compared as intermediate fluids and it was found that ethanol-CO2 critical point dried specimens shrank more before and after CPD than Freon 113-CO2 specimens. The latter technique is, therefore, to be recommended. Potato tissue shrinks in 30% ethanol, whereas animal tissues all swell in this concentration. The potato tissue also shrank very litte on critical point drying in contrast to the animal tissue specimens. PMID:6999595

  14. Variability Between Vials of Cryopreserved Shoot Tips from Tissue Cultured Plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    At the USDA-ARS National Center for Genetic Resources Preservation, cryopreservation is used as a method of long-term storage of valuable plant genetic resources from vegetatively-propagated crop plants. The main germplasm collections for vegetatively-propagated crops are maintained as field planti...

  15. Three-dimensional reconstruction of frozen and thawed plant tissues from microscopic images

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Histological analysis of frozen and thawed plants has been conducted for many years but the observation of individual sections only provides a 2 dimensional representation of a 3 dimensional phenomenon. Most techniques for viewing internal plant structure in 3 dimensions is either low in resolution...

  16. EXTRACTION AND DETERMINATION OF SELECTED POLYCYCLIC AROMATIC HYDROCARBONS IN PLANT TISSUES

    EPA Science Inventory

    A procedure has been developed for analysis of plant material for polycyclic aromatic hydrocarbons (PAHs). Sonication is used to extract the PAHs from homogenized plant material into acetonitrile and then the PAHs are partitioned into pentane. The pentane extract is fractionated ...

  17. Application of supercritical CO2 for extraction of polyisoprenoid alcohols and their esters from plant tissues[S

    PubMed Central

    Jozwiak, Adam; Brzozowski, Robert; Bujnowski, Zygmunt; Chojnacki, Tadeusz; Swiezewska, Ewa

    2013-01-01

    In this study, a method of supercritical fluid extraction (SFE) with carbon dioxide of polyisoprenoids from plant photosynthetic tissues is described. SFE was an effective extraction method for short- and medium-chain compounds with even higher yield than that observed for the “classical extraction” method with organic solvents. Moreover, SFE-derived extracts contained lower amounts of impurities (e.g., chlorophylls) than those obtained by extraction of the same tissue with organic solvents. Elevated temperature and extended extraction time of SFE resulted in a higher rate of extraction of long-chain polyisoprenoids. Ethanol cofeeding did not increase the extraction efficiency of polyisoprenoids; instead, it increased the content of impurities in the lipid extract. Optimization of SFE time and temperature gives the opportunity of prefractionation of complex polyisoprenoid mixtures accumulated in plant tissues. Extracts obtained with application of SFE are very stable and free from organic solvents and can further be used directly in experimental diet supplementation or as starting material for preparation of semisynthetic polyisoprenoid derivatives, e.g., polyisoprenoid phosphates. PMID:23673976

  18. Seasonal availability of edible underground and aboveground carbohydrate resources to human foragers on the Cape south coast, South Africa

    PubMed Central

    Cowling, Richard M.; Potts, Alastair J.; Marean, Curtis W.

    2016-01-01

    The coastal environments of South Africa’s Cape Floristic Region (CFR) provide some of the earliest and most abundant evidence for the emergence of cognitively modern humans. In particular, the south coast of the CFR provided a uniquely diverse resource base for hunter-gatherers, which included marine shellfish, game, and carbohydrate-bearing plants, especially those with Underground Storage Organs (USOs). It has been hypothesized that these resources underpinned the continuity of human occupation in the region since the Middle Pleistocene. Very little research has been conducted on the foraging potential of carbohydrate resources in the CFR. This study focuses on the seasonal availability of plants with edible carbohydrates at six-weekly intervals over a two-year period in four vegetation types on South Africa’s Cape south coast. Different plant species were considered available to foragers if the edible carbohydrate was directly (i.e. above-ground edible portions) or indirectly (above-ground indications to below-ground edible portions) visible to an expert botanist familiar with this landscape. A total of 52 edible plant species were recorded across all vegetation types. Of these, 33 species were geophytes with edible USOs and 21 species had aboveground edible carbohydrates. Limestone Fynbos had the richest flora, followed by Strandveld, Renosterveld and lastly, Sand Fynbos. The availability of plant species differed across vegetation types and between survey years. The number of available USO species was highest for a six-month period from winter to early summer (Jul–Dec) across all vegetation types. Months of lowest species’ availability were in mid-summer to early autumn (Jan–Apr); the early winter (May–Jun) values were variable, being highest in Limestone Fynbos. However, even during the late summer carbohydrate “crunch,” 25 carbohydrate bearing species were visible across the four vegetation types. To establish a robust resource landscape

  19. Dynamics of aboveground carbon stocks in a selectively logged tropical forest.

    PubMed

    Blanc, Lilian; Echard, Marion; Herault, Bruno; Bonal, Damien; Marcon, Eric; Chave, Jérôme; Baraloto, Christopher

    2009-09-01

    The expansion of selective logging in tropical forests may be an important source of global carbon emissions. However, the effects of logging practices on the carbon cycle have never been quantified over long periods of time. We followed the fate of more than 60 000 tropical trees over 23 years to assess changes in aboveground carbon stocks in 48 1.56-ha plots in French Guiana that represent a gradient of timber harvest intensities, with and without intensive timber stand improvement (TSI) treatments to stimulate timber tree growth. Conventional selective logging led to emissions equivalent to more than a third of aboveground carbon stocks in plots without TSI (85 Mg C/ha), while plots with TSI lost more than one-half of aboveground carbon stocks (142 Mg C/ha). Within 20 years of logging, plots without TSI sequestered aboveground carbon equivalent to more than 80% of aboveground carbon lost to logging (-70.7 Mg C/ha), and our simulations predicted an equilibrium aboveground carbon balance within 45 years of logging. In contrast, plots with intensive TSI are predicted to require more than 100 years to sequester aboveground carbon lost to emissions. These results indicate that in some tropical forests aboveground carbon storage can be recovered within half a century after conventional logging at moderate harvest intensities. PMID:19769089

  20. The determination of 22 natural brassinosteroids in a minute sample of plant tissue by UHPLC-ESI-MS/MS.

    PubMed

    Tarkowská, Danuše; Novák, Ondřej; Oklestkova, Jana; Strnad, Miroslav

    2016-09-01

    The triterpenoid plant hormones brassinosteroids (BRs) are believed to influence almost every aspect of plant growth and development. We have developed a sensitive mass spectrometry-based method for the simultaneous profiling of twenty-two naturally occurring brassinosteroids including biosynthetic precursors and the majority of biologically active metabolites. Using ultra-high performance liquid chromatographic (UHPLC) analysis, the run time was reduced up to three times (to 9 min) in comparison to standard HPLC BRs analyses, the retention time stability was improved to 0.1-0.2 % RSD and the injection accuracy was increased to 1.1-4.9 % RSD. The procedures for extraction and for two-step purification based on solid-phase extraction (SPE) were optimised in combination with subsequent UHPLC analysis coupled to electrospray ionisation tandem mass spectrometry (ESI-MS/MS) using Brassica flowers and Arabidopsis plant tissue extracts. In multiple reaction monitoring (MRM) mode, the average detection limit for BRs analysed was close to 7 pg, and the linear range covered up to 3 orders of magnitude. The low detection limits for this broad range of BR metabolites enabled as little as 50 mg of plant tissue to be used for quantitative analyses. The results of determinations exploiting internal standards showed that this approach provides a high level of practicality, reproducibility and recovery. The method we have established will enable researchers to gain a better understanding of the dynamics of the biosynthesis and metabolism of brassinosteroids and their modes of action in plant growth and development. PMID:27531032

  1. Diversity and Above-Ground Biomass Patterns of Vascular Flora Induced by Flooding in the Drawdown Area of China's Three Gorges Reservoir

    PubMed Central

    Wang, Qiang; Yuan, Xingzhong; Willison, J.H.Martin; Zhang, Yuewei; Liu, Hong

    2014-01-01

    Hydrological alternation can dramatically influence riparian environments and shape riparian vegetation zonation. However, it was difficult to predict the status in the drawdown area of the Three Gorges Reservoir (TGR), because the hydrological regime created by the dam involves both short periods of summer flooding and long-term winter impoundment for half a year. In order to examine the effects of hydrological alternation on plant diversity and biomass in the drawdown area of TGR, twelve sites distributed along the length of the drawdown area of TGR were chosen to explore the lateral pattern of plant diversity and above-ground biomass at the ends of growing seasons in 2009 and 2010. We recorded 175 vascular plant species in 2009 and 127 in 2010, indicating that a significant loss of vascular flora in the drawdown area of TGR resulted from the new hydrological regimes. Cynodon dactylon and Cyperus rotundus had high tolerance to short periods of summer flooding and long-term winter flooding. Almost half of the remnant species were annuals. Species richness, Shannon-Wiener Index and above-ground biomass of vegetation exhibited an increasing pattern along the elevation gradient, being greater at higher elevations subjected to lower submergence stress. Plant diversity, above-ground biomass and species distribution were significantly influenced by the duration of submergence relative to elevation in both summer and previous winter. Several million tonnes of vegetation would be accumulated on the drawdown area of TGR in every summer and some adverse environmental problems may be introduced when it was submerged in winter. We conclude that vascular flora biodiversity in the drawdown area of TGR has dramatically declined after the impoundment to full capacity. The new hydrological condition, characterized by long-term winter flooding and short periods of summer flooding, determined vegetation biodiversity and above-ground biomass patterns along the elevation gradient in

  2. Evaluating lidar point densities for effective estimation of aboveground biomass

    USGS Publications Warehouse

    Wu, Zhuoting; Dye, Dennis G.; Stoker, Jason; Vogel, John M.; Velasco, Miguel G.; Middleton, Barry R.

    2016-01-01

    The U.S. Geological Survey (USGS) 3D Elevation Program (3DEP) was recently established to provide airborne lidar data coverage on a national scale. As part of a broader research effort of the USGS to develop an effective remote sensing-based methodology for the creation of an operational biomass Essential Climate Variable (Biomass ECV) data product, we evaluated the performance of airborne lidar data at various pulse densities against Landsat 8 satellite imagery in estimating above ground biomass for forests and woodlands in a study area in east-central Arizona, U.S. High point density airborne lidar data, were randomly sampled to produce five lidar datasets with reduced densities ranging from 0.5 to 8 point(s)/m2, corresponding to the point density range of 3DEP to provide national lidar coverage over time. Lidar-derived aboveground biomass estimate errors showed an overall decreasing trend as lidar point density increased from 0.5 to 8 points/m2. Landsat 8-based aboveground biomass estimates produced errors larger than the lowest lidar point density of 0.5 point/m2, and therefore Landsat 8 observations alone were ineffective relative to airborne lidar for generating a Biomass ECV product, at least for the forest and woodland vegetation types of the Southwestern U.S. While a national Biomass ECV product with optimal accuracy could potentially be achieved with 3DEP data at 8 points/m2, our results indicate that even lower density lidar data could be sufficient to provide a national Biomass ECV product with accuracies significantly higher than that from Landsat observations alone.

  3. Using spontaneous photon emission to image lipid oxidation patterns in plant tissues.

    PubMed

    Birtic, Simona; Ksas, Brigitte; Genty, Bernard; Mueller, Martin J; Triantaphylidès, Christian; Havaux, Michel

    2011-09-01

    Plants, like almost all living organisms, spontaneously emit photons of visible light. We used a highly sensitive, low-noise cooled charge coupled device camera to image spontaneous photon emission (autoluminescence) of plants. Oxidative stress and wounding induced a long-lasting enhancement of plant autoluminescence, the origin of which is investigated here. This long-lived phenomenon can be distinguished from the short-lived chlorophyll luminescence resulting from charge recombinations within the photosystems by pre-adapting the plant to darkness for about 2 h. Lipids in solvent were found to emit a persistent luminescence after oxidation in vitro, which exhibited the same time and temperature dependence as plant autoluminescence. Other biological molecules, such as DNA or proteins, either did not produce measurable light upon oxidation or they did produce a chemiluminescence that decayed rapidly, which excludes their significant contribution to the in vivo light emission signal. Selective manipulation of the lipid oxidation levels in Arabidopsis mutants affected in lipid hydroperoxide metabolism revealed a causal link between leaf autoluminescence and lipid oxidation. Addition of chlorophyll to oxidized lipids enhanced light emission. Both oxidized lipids and plants predominantly emit light at wavelengths higher than 600 nm; the emission spectrum of plant autoluminescence was shifted towards even higher wavelengths, a phenomenon ascribable to chlorophyll molecules acting as luminescence enhancers in vivo. Taken together, the presented results show that spontaneous photon emission imaged in plants mainly emanates from oxidized lipids. Imaging of this signal thus provides a simple and sensitive non-invasive method to selectively visualize and map patterns of lipid oxidation in plants. PMID:21595761

  4. LogSpin: a simple, economical and fast method for RNA isolation from infected or healthy plants and other eukaryotic tissues

    PubMed Central

    2012-01-01

    Background Rapid RNA extraction is commonly performed with commercial kits, which are very expensive and can involve toxic reagents. Most of these kits can be used with healthy plant tissues, but do not produce consistently high-quality RNA from necrotic fungus-infected tissues or fungal mycelium. Findings We report on the development of a rapid and relatively inexpensive method for total RNA extraction from plants and fungus-infected tissues, as well as from insects and fungi, based on guanidine hydrochloride buffer and common DNA extraction columns originally used for the extraction and purification of plasmids and cosmids. Conclusions The proposed method can be used reproducibly for RNA isolation from a variety of plant species. It can also be used with infected plant tissue and fungal mycelia, which are typically recalcitrant to standard nucleic acid extraction procedures. PMID:22260178

  5. The regeneration of epidermal cells of Saintpaulia leaves as a new plant-tissue system for cellular radiation biology.

    PubMed

    Engels, F M; van der Laan, F M; Leenhouts, H P; Chadwick, K H

    1980-09-01

    Investigation of the nucleus of epidermal cells of the petioles of Saintpaulia leaves by cytofluorimetry revealed that all cells are in a non-cycling pre DNA synthesis phase. Cultivation of dissected leaves results in a synchronous regeneration process of a defined number of cells. Five days after onset of cultivation the cells reach the first mitosis. The nuclear development during the regeneration process is described. Irradiation of the leaves results in a directly visible inhibition of this regenerating capability which is used to quantify cell survival in a tissue. The data show that the radiation response has a similar shape to that of the survival of single cells in culture. This response can be observed before the first mitosis of the cells and its application as a new plant tissue system for cellular radiation research is discussed. PMID:7012060

  6. Analysis of S-methylmethionine and S-adenosylmethionine in plant tissue by a dansylation, Dual-isotope method

    SciTech Connect

    Macnicol, P.K.

    1986-10-01

    A method is presented for determining the levels of S-methylmethionine (MeMet) and S-adenosylmethionine (AdoMet) in the same plant tissue sample, utilizing readily available equipment. The bottom limit of sensitivity, ca. 100 pmol, can be lowered if required. A trichloracetic acid homogenate of the tissue is supplemented with (carboxyl-/sup 14/C)MeMet and (carboxyl-/sup 14/C)AdoMet. After separation of MeMet and AdoMet from each other and from endogenous homoserine on a phosphocellulose column, the two fractions are heat treated at appropriate pH values to liberate (/sup 14/C)homoserine. Quantitation is via the /sup 3/H//sup 14/C ratio of (/sup 3/H)dansyl-(/sup 14/C)homoserine isolated by thin-layer chromatography. The method is validated with pea cotyledon, corn root, and cauliflower leaf.

  7. Tissue culture and generation of autotetraploid plants of Sophora flavescens Aiton

    PubMed Central

    Kun-Hua, Wei; Shan-Lin, Gao; He-Ping, Huang

    2010-01-01

    Background: Sophora flavescens Aiton is an important medicinal plant in China. Early in vitro researches of S. flavescens were focused on callus induction and cell suspension culture, only a few were concerned with in vitro multiplication. Objective: To establish and optimize the rapid propagation technology of S. flavescens and to generate and characterize polyploid plants of S. flavescens. Materials and Methods: The different concentrations of 6-benzylaminopurine (BAP), indole-3-acetic acid (IAA) and kinetin (KT) were used to establish and screen the optimal rapid propagation technology of S. flavescens by orthogonal test; 0.2% colchicine solution was used to induce polyploid plants and the induced buds were identified by root-tip chromosome determination and stomatal apparatus observation. Results: A large number of buds could be induced directly from epicotyl and hypocotyl explants on the Murashige and Skoog medium (MS; 1962) supplemented with 1.4–1.6 mg/l 6-benzylaminopurine (BAP) and 0.3 mg/l indole-3-acetic acid (IAA). More than 50 lines of autotetraploid plants were obtained. The chromosome number of the autotetraploid plantlet was 2n = 4× = 36. All tetraploid plants showed typical polyploid characteristics. Conclusion: Obtained autotetraploid lines will be of important genetic and breeding value and can be used for further selection and plant breeding. PMID:21120030

  8. Responses of Soil Bacterial Communities to Nitrogen Deposition and Precipitation Increment Are Closely Linked with Aboveground Community Variation.

    PubMed

    Li, Hui; Xu, Zhuwen; Yang, Shan; Li, Xiaobin; Top, Eva M; Wang, Ruzhen; Zhang, Yuge; Cai, Jiangping; Yao, Fei; Han, Xingguo; Jiang, Yong

    2016-05-01

    It has been predicted that precipitation and atmospheric nitrogen (N) deposition will increase in northern China; yet, ecosystem responses to the interactive effects of water and N remain largely unknown. In particular, responses of belowground microbial community to projected global change and their potential linkages to aboveground macro-organisms are rarely studied. In this study, we examined the responses of soil bacterial diversity and community composition to increased precipitation and multi-level N deposition in a temperate steppe in Inner Mongolia, China, and explored the diversity linkages between aboveground and belowground communities. It was observed that N addition caused the significant decrease in bacterial alpha-diversity and dramatic changes in community composition. In addition, we documented strong correlations of alpha- and beta-diversity between plant and bacterial communities in response to N addition. It was found that N enriched the so-called copiotrophic bacteria, but reduced the oligotrophic groups, primarily by increasing the soil inorganic N content and carbon availability and decreasing soil pH. We still highlighted that increased precipitation tended to alleviate the effects of N on bacterial diversity and dampen the plant-microbe connections induced by N. The counteractive effects of N addition and increased precipitation imply that even though the ecosystem diversity and function are predicted to be negatively affected by N deposition in the coming decades; the combination with increased precipitation may partially offset this detrimental effect. PMID:26838999

  9. Grazing effects on aboveground primary production and root biomass of early-seral, mid-seral, and undisturbed semiarid grassland

    USGS Publications Warehouse

    Milchunas, D.G.; Vandever, M.W.

    2013-01-01

    Annual/perennial and tall/short plant species differentially dominate early to late successional shortgrass steppe communities. Plant species can have different ratios of above-/below-ground biomass distributions and this can be modified by precipitation and grazing. We compared grazing effects on aboveground production and root biomass in early- and mid-seral fields and undisturbed shortgrass steppe. Production averaged across four years and grazed and ungrazed treatments were 246, 134, and 102 g m−2 yr−1 for the early-, mid-seral, and native sites, respectively, while root biomass averaged 358, 560, and 981 g m−2, respectively. Early- and mid-seral communities provided complimentary forage supplies but at the cost of root biomass. Grazing increased, decreased, or had no effect on aboveground production in early-, mid-seral, and native communities, and had no effect on roots in any. Grazing had some negative effects on early spring forage species, but not in the annual dominated early-seral community. Dominant species increased with grazing in native communities with a long evolutionary history of grazing by large herbivores, but had no effects on the same species in mid-seral communities. Effects of grazing in native communities in a region cannot necessarily be used to predict effects at other seral stages.

  10. Bog Plant Tissue Chemistry as Indicators of Regionally Elevated Atmospheric N and S Deposition in the Alberta Oil Sands Region

    NASA Astrophysics Data System (ADS)

    Wieder, R.; Vile, M. A.; Scott, K. D.; Vitt, D. H.; Quinn, J.

    2011-12-01

    Nitrogen oxide and sulfur oxide emission from ongoing development of oil sands in northern Alberta results in regionally elevated atmospheric deposition of N and S in an area where background deposition of both N and S is exceptionally low (less than 1 kg/ha/yr). Because bogs, which represent major landforms in the Alberta oil sands region, are believed to be N-limited and potentially sensitive to S inputs, we have been investigating the effects of elevated N deposition on C, N, and S cycling in bogs, as well as the potential of bogs to serve as monitors of N and S deposition. Toward this latter end, we have measured seasonal variation (5 sampling dates between June and October 2009) concentrations of N and S, as well as δ15N value, in leaf tissues (Picea mariana (ectomycorrhizal); Ledum groenlandicum, Oxycoccos microcarpon, Vaccinium vitis-idaea (ericoid mycorrhizal); Rubus chamaemorus, and Smilacina trifolia (nonmycorrhizal), Sphagnum (S. fuscum, S. capillifolium, S. magellanicum, S. angustifolium) moss capitula (top 1-cm of plant) and lichens (Cladina mitis and Evernia mesomorpha) at 5 bogs at distances ranging from 14 to 300 km from the heart of the oil sands mining area. Averaged across all sites and sampling dates, N concentrations in ectomycorrhizal, ericoid mycorrhizal, nonmycorrhizal, Sphagnum, and lichens was 8.6 + 0.2, 11.9 + 0.2, 26.3 + 0.6, 10.2 + 0.1, 7.2 + 0.2 mg/g, respectively; δ15N values were -10.3 + 0.1, -6.0 + 0.1, 1.7 + 0.2, -5.3 + 0.1, -4.7 + 0.1 mg/g, respectively, and S concentrations were 1.07 + 0.2, 1.31 + 0.2, 1.94 + 0.6, 1.46 + 0.2, 1.11 + 0.3 mg/g, respectively. Plant functional groups and individual species behaved differently with respect to both seasonal variation and site differences, often with significant interactions when analyzed using two-way analyses of variance. Some species exhibited seasonal variation in some aspects

  11. The signature of seeds in resurrection plants: a molecular and physiological comparison of desiccation tolerance in seeds and vegetative tissues.

    PubMed

    Illing, Nicola; Denby, Katherine J; Collett, Helen; Shen, Arthur; Farrant, Jill M

    2005-11-01

    Desiccation-tolerance in vegetative tissues of angiosperms has a polyphyletic origin and could be due to 1) appropriation of the seed-specific program of gene expression that protects orthodox seeds against desiccation, and/or 2) a sustainable version of the abiotic stress response. We tested these hypotheses by comparing molecular and physiological data from the development of orthodox seeds, the response of desiccation-sensitive plants to abiotic stress, and the response of desiccation-tolerant plants to extreme water loss. Analysis of publicly-available gene expression data of 35 LEA proteins and 68 anti-oxidant enzymes in the desiccation-sensitive Arabidopsis thaliana identified 13 LEAs and 4 anti-oxidants exclusively expressed in seeds. Two (a LEA6 and 1-cys-peroxiredoxin) are not expressed in vegetative tissues in A. thaliana, but have orthologues that are specifically activated in desiccating leaves of Xerophyta humilis. A comparison of antioxidant enzyme activity in two desiccation-sensitive species of Eragrostis with the desiccation-tolerant E. nindensis showed equivalent responses upon initial dehydration, but activity was retained at low water content in E. nindensis only. We propose that these antioxidants are housekeeping enzymes and that they are protected from damage in the desiccation-tolerant species. Sucrose is considered an important protectant against desiccation in orthodox seeds, and we show that sucrose accumulates in drying leaves of E. nindensis, but not in the desiccation-sensitive Eragrostis species. The activation of "seed-specific" desiccation protection mechanisms (sucrose accumulation and expression of LEA6 and 1-cys-peroxiredoxin genes) in the vegetative tissues of desiccation-tolerant plants points towards acquisition of desiccation tolerance from seeds. PMID:21676829

  12. Increased plant sterol deposition in vascular tissue characterizes patients with severe aortic stenosis and concomitant coronary artery disease.

    PubMed

    Luister, Alexandra; Schött, Hans Frieder; Husche, Constanze; Schäfers, Hans-Joachim; Böhm, Michael; Plat, Jogchum; Gräber, Stefan; Lütjohann, Dieter; Laufs, Ulrich; Weingärtner, Oliver

    2015-07-01

    The aim of the study was to evaluate the relationship between phytosterols, oxyphytosterols, and other markers of cholesterol metabolism and concomitant coronary artery disease (CAD) in patients with severe aortic stenosis who were scheduled for elective aortic valve replacement. Markers of cholesterol metabolism (plant sterols and cholestanol as markers of cholesterol absorption and lathosterol as an indicator of cholesterol synthesis) and oxyphytosterols were determined in plasma and aortic valve tissue from 104 consecutive patients with severe aortic stenosis (n=68 statin treatment; n=36 no statin treatment) using gas chromatography-flame ionization and mass spectrometry. The extent of CAD was determined by coronary angiography prior to aortic valve replacement. Patients treated with statins were characterized by lower plasma cholesterol, cholestanol, and lathosterol concentrations. However, statin treatment did not affect the sterol concentrations in cardiovascular tissue. The ratio of campesterol-to-cholesterol was increased by 0.46±0.34μg/mg (26.0%) in plasma of patients with CAD. The absolute values for the cholesterol absorption markers sitosterol and campesterol were increased by 18.18±11.59ng/mg (38.8%) and 11.40±8.69ng/mg (30.4%) in the tissues from patients with documented CAD compared to those without concomitant CAD. Campesterol oxides were increased by 0.06±0.02ng/mg (17.1%) in the aortic valve cusps and oxidized sitosterol-to-cholesterol ratios were up-regulated by 0.35±0.2ng/mg (22.7%) in the plasma of patients with CAD. Of note, neither cholestanol nor the ratio of cholestanol-to-cholesterol was associated with CAD. Patients with concomitant CAD are characterized by increased deposition of plant sterols, but not cholestanol in aortic valve tissue. Moreover, patients with concomitant CAD were characterized by increased oxyphytosterol concentrations in plasma and aortic valve cusps. PMID:25814070

  13. Growth of plant tissue cultures in simulated lunar soil: Implications for a lunar base Controlled Ecological Life Support System (CELSS)

    NASA Technical Reports Server (NTRS)

    Venketeswaran, S.

    1987-01-01

    Experiments to determine whether plant tissue cultures can be grown in the presence of simulated lunar soil (SLS) and the effect of simulated lunar soil on the growth and morphogenesis of such cultures, as well as the effect upon the germination of seeds and the development of seedlings were carried out . Preliminary results on seed germination and seedling growth of rice and calli growth of winged bean and soybean indicate that there is no toxicity or inhibition caused by SLS. SLS can be used as a support medium with supplements of certain major and micro elements.

  14. Phylogenic diversity and tissue specificity of fungal endophytes associated with the pharmaceutical plant, Stellera chamaejasme L. revealed by a cultivation-independent approach.

    PubMed

    Jin, Hui; Yang, Xiaoyan; Lu, Dengxue; Li, Chunjie; Yan, Zhiqiang; Li, Xiuzhuang; Zeng, Liming; Qin, Bo

    2015-10-01

    The fungal endophytes associated with medicinal plants have been demonstrated as a reservoir with novel natural products useful in medicine and agriculture. It is desirable to explore the species composition, diversity and tissue specificity of endophytic fungi that inhabit in different tissues of medicinal plants. In this study, a culture-independent survey of fungal diversity in the rhizosphere, leaves, stems and roots of a toxic medicinal plant, Stellera chamaejasme L., was conducted by sequence analysis of clone libraries of the partial internal transcribed spacer region. Altogether, 145 fungal OTUs (operational taxonomic units), represented by 464 sequences, were found in four samples, of these 109 OTUs (75.2 %) belonging to Ascomycota, 20 (13.8 %) to Basidiomycota, 14 (9.7 %) to Zygomycota, 1 (0.7 %) to Chytridiomycota, and 1 (0.7 %) to Glomeromycota. The richness and diversity of fungal communities were strongly influenced by plant tissue environments, and the roots are associated with a surprisingly rich endophyte community. The endophyte assemblages associated with S. chamaejasme were strongly shaped by plant tissue environments, and exhibited a certain degree of tissue specificity. Our results suggested that a wide variety of fungal assemblages inhabit in S. chamaejasme, and plant tissue environments conspicuously influence endophyte community structure. PMID:26194722

  15. Microautoradiography of Water-Soluble Compounds in Plant Tissue after Freeze-Drying and Pressure Infiltration with Epoxy Resin

    PubMed Central

    Vogelmann, Thomas C.; Dickson, Richard E.

    1982-01-01

    It is difficult to retain and localize radioactive, water-soluble compounds within plant cells. Existing techniques retain water-soluble compounds with varying rates of efficiency and are limited to processing only a few samples at one time. We developed a modified pressure infiltration technique for the preparation of microautoradiographs of 14C-labeled, water-soluble compounds in plant tissue. Samples from cottonwood (Populus deltoides Bartr. ex Marsh.) labeled with 14C were excised, quick frozen in liquid N2, freeze-dried at −50°C, and pressure-infiltrated with epoxy resin without intermediate solvents or prolonged incubation times. The technique facilitates the mass processing of samples for microautoradiography, gives good cellular retention of labeled water-soluble compounds, and is highly reproducible. Images Fig. 2 PMID:16662542

  16. Evaluation of two-dimensional electrophoresis and liquid chromatography – tandem mass spectrometry for tissue-specific protein profiling of laser-microdissected plant samples

    SciTech Connect

    Schad, Martina; Lipton, Mary S.; Giavalisco, Patrick; Smith, Richard D.; Kehr, Julia

    2005-07-14

    Laser microdissection (LM) allows the collection of homogeneous tissue- and cell specific plant samples. The employment of this technique with subsequent protein analysis has thus far not been reported for plant tissues, probably due to the difficulties associated with defining a reasonable cellular morphology and, in parallel, allowing efficient protein extraction from tissue samples. The relatively large sample amount needed for successful proteome analysis is an additional issue that complicates protein profiling on a tissue- or even cell-specific level. In contrast to transcript profiling that can be performed from very small sample amounts due to efficient amplification strategies, there is as yet no amplification procedure for proteins available. In the current study, we compared different tissue preparation techniques prior to LM/laser pressure catapulting (LMPC) with respect to their suitability for protein retrieval. Cryosectioning was identified as the best compromise between tissue morphology and effective protein extraction. After collection of vascular bundles from Arabidopsis thaliana stem tissue by LMPC, proteins were extracted and subjected to protein analysis, either by classical two-dimensional gel electrophoresis (2-DE), or by high-efficiency liquid chromatography (LC) in conjunction with tandem mass spectrometry (MS/MS). Our results demonstrate that both methods can be used with LMPC collected plant material. But because of the significantly lower sample amount required for LC-MS/MS than for 2-DE, the combination of LMPC and LC-MS/MS has a higher potential to promote comprehensive proteome analysis of specific plant tissues.

  17. Fixing and sectioning tissue from the plant Kalanchoë daigremontiana.

    PubMed

    Garcês, Helena; Sinha, Neelima

    2009-10-01

    Tissue samples from Kalanchoë daigremontiana can be fixed for scanning electron microscopy (SEM), histology, and in situ hybridization using several common steps described in this protocol. All steps should be performed in the same manner for all three methods unless otherwise noted. PMID:20147046

  18. DISEASE DEVELOPMENT AND SYMPTOM EXPRESSION OF XANTHOMONAS AXONOPODIS PV. CITRI IN VARIOUS CITRUS PLANT TISSUES.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Experimental inoculations of Xanthomonas axonopodis pv. citri (Xac) in different tissues of Tahiti lime and Pineapple sweet orange were conducted monthly under natural conditions in Réunion Island. The interactions between a set of environmental and epidemic variables associated with disease express...

  19. Cell shapes and patterns as quantitative indicators of tissue stress in the plant epidermis.

    PubMed

    Kim, Sangwoo; Hilgenfeldt, Sascha

    2015-10-01

    In a confluent, single-cell tissue layer, we show that cell shapes and statistics correlate directly with the tissue's mechanical properties, described by an energy functional with generic interfacial terms only. Upon increasing the cohesive component of the model, we observe a clear transition from a tense state with isotropic cells to a relaxed state with anisotropic cells. Signatures of the transition are present in the interfacial mechanics, the domain geometry, and the domain statistics, thus linking all three fields of study. This transition persists for all cell size distributions, but its exact position is crucially dependent on fluctuations in the parameter values of the functional (quenched disorder). The magnitude of fluctuations can be matched to the observed shape distribution of cells, so that visual observation of cell shapes and statistics provides information about the mechanical state of the tissue. Comparing with experimental data from the Cucumis epidermis, we find that the system is located right at the transition, allowing the tissue to relieve most of the local stress while maintaining integrity. PMID:26264286

  20. A simple method for comparing fungal biomass in infected plant tissues.

    PubMed

    Ayliffe, Michael; Periyannan, Sambasivam K; Feechan, Angela; Dry, Ian; Schumann, Ulrike; Wang, Ming-Bo; Pryor, Anthony; Lagudah, Evans

    2013-06-01

    Plant phenotypes resistant and susceptible to fungal pathogens are usually scored using qualitative, subjective methods that are based upon disease symptoms or by an estimation of the amount of visible fungal growth. Given that plant resistance genes often confer partial resistance to fungal pathogens, a simple, sensitive, nonsubjective quantitative method for measuring pathogen growth would be highly advantageous. This report describes an in planta quantitative assay for fungal biomass based upon detection of chitin using wheat germ agglutinin conjugated to a fluorophore. Using this assay, the growth of wheat rust pathogens on wheat was assayed and the additivity of several adult plant and seedling resistance genes to Puccinia striiformis, P. graminis, and P. triticina was assayed on both glasshouse- and field-grown material. The assay can discriminate between individual rust pustules on a leaf segment or, alternatively, compare fungal growth on field plots. The quantification of Erysiphe necator (powdery mildew) growth on Vitis vinifera (grapevine) is also demonstrated, with resistant and susceptible cultivars readily distinguished. Given that chitin is a major cell wall component of many plant fungal pathogens, this robust assay will enable simple and accurate measurement of biomass accumulation in many plant-fungus interactions. PMID:23405866

  1. Secondary Ion Mass Spectrometry (SIMS) Microscopy as an Imaging Tool for Physiological Studies II. SIMS Microscopy of Plant Tissues

    NASA Astrophysics Data System (ADS)

    Grignon, Nicole; Halpern, Sylvain; Jeusset, Josette; Fragu, Philippe

    1996-06-01

    Serious difficulties are encountered when SIMS analysis is applied to plant cells because of the cells' basic organization. In most plant cells, the cytoplasm is present as a thin layer that surrounds a large central vacuole, and is surrounded externally by a porous semi-rigid cell wall. Due to the high internal hydrostatic pressure typical of plant cells, large-scale solute redistribution may occur when tissues are excised. Relatively small solute decompartmentation is sufficient to collapse the native solute gradients between the cytoplasm and the adjacent compartments, due to the small volume of the former. For these reasons, most of the SIMS analyses in plant cells have been performed on elements bound to non-diffusible structures such as proteins, cell wall polymers, or in dry seeds. Sample preparation remains a limiting factor when imaging the distribution of soluble compounds. Cryotechniques have generated considerable interest to circumvent these problems. Cryofixation followed by cryosectioning would a priori be the best procedure, but encouraging results indicate that cryofixation followed by cryosubstitution is an interesting alternative.

  2. Analysis of laser-induced fluorescence spectra of in vitro plant tissue cultures

    NASA Astrophysics Data System (ADS)

    Muñoz-Muñoz, Ana Celia; Gutiérrez-Pulido, Humberto; Rodríguez-Domínguez, José Manuel; Gutiérrez-Mora, Antonia; Rodríguez-Garay, Benjamín; Cervantes-Martínez, Jesús

    2007-04-01

    We demonstrate the effectiveness of laser-induced fluorescence (LIF) for monitoring the development and stress detection of in vitro tissue cultures in a nondestructive and noninvasive way. The changes in LIF spectra caused by the induction of organogenesis, the increase of the F690/F740 ratio as a result of the stress originated in the organogenic explants due to shoot emergence, and the relationship between fluorescence spectra and shoot development were detected by LIF through closed containers of Saintpaulia ionantha.

  3. Development of rapid isothermal amplification assays for Phytophthora species from plant tissue

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several isothermal amplification techniques recently have been developed that are tolerant of inhibitors present in many plant extracts, which can reduce the need for obtaining purified DNA for running diagnostic assays. One such commercially available technique that has similarities with real time ...

  4. Mercury Concentrations in Plant Tissues as Affected by FGDG Application to Soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flue Gas Desulfurization Gypsum (FGDG) is produced by reducing sulfur dioxide emissions from themo-electric coal-fired power plants. The most common practice of FGDG production may trap some of the Mercury (Hg) present in the coal that normally would escape as vapor in the stack gases. Concern for t...

  5. Spatio-Temporal Imaging of Promoter Activity in Intact Plant Tissues.

    PubMed

    Xiong, Tou Cheu; Sanchez, Frédéric; Briat, Jean-François; Gaymard, Frédéric; Dubos, Christian

    2016-01-01

    Localization and quantification of expression levels of genes help to determine their function. Localization of gene expression is often achieved through the study of their promoter activity. Three main reporter genes β-glucuronidase (GUS), green fluorescent protein (GFP), and luciferase (LUC) have been intensively used to characterize promoter activities, each having its own specificities and advantages. Among them, the LUC reporter gene is best suitable for the analysis of the promoter activity of genes in intact living plants. Here, we describe a LUC-based method that allows to precisely localize and quantify promoter activity at the whole plant level, and to study the mechanisms that are involved in long-distance regulation of gene expression in Arabidopsis thaliana. Imaging LUC signals with a low-light CCD camera allows monitoring promoter activity in time and space in the transgenic plant harboring the promoter fused with the LUC gene. In addition, it allows quantifying change of promoter activities in plant during several hours. PMID:27557763

  6. Extraction and analysis of inositols and other carbohydrates from soybean plant tissues

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An outstanding characteristic of soybean plants is their ability to produce large amounts of the carbohydrate pinitol. Pinitol and the closely related inositols are currently undergoing widespread investigation for their biological and nutritional value. These and all the carbohydrates are typical...

  7. Proton-dependent coniferin transport, a common major transport event in differentiating xylem tissue of woody plants.

    PubMed

    Tsuyama, Taku; Kawai, Ryo; Shitan, Nobukazu; Matoh, Toru; Sugiyama, Junji; Yoshinaga, Arata; Takabe, Keiji; Fujita, Minoru; Yazaki, Kazufumi

    2013-06-01

    Lignin biosynthesis is an essential physiological activity of vascular plants if they are to survive under various environmental stresses on land. The biosynthesis of lignin proceeds in the cell wall by polymerization of precursors; the initial step of lignin polymerization is the transportation of lignin monomers from the cytosol to the cell wall, which is critical for lignin formation. There has been much debate on the transported form of the lignin precursor, either as free monolignols or their glucosides. In this study, we performed biochemical analyses to characterize the membrane transport mechanism of lignin precursors using angiosperms, hybrid poplar (Populus sieboldii × Populus grandidentata) and poplar (Populus sieboldii), as well gymnosperms, Japanese cypress (Chamaecyparis obtusa) and pine (Pinus densiflora). Membrane vesicles prepared from differentiating xylem tissues showed clear ATP-dependent transport activity of coniferin, whereas less than 4% of the coniferin transport activity was seen for coniferyl alcohol. Bafilomycin A1 and proton gradient erasers markedly inhibited coniferin transport in hybrid poplar membrane vesicles; in contrast, vanadate had no effect. Cis-inhibition experiments suggested that this transport activity was specific for coniferin. Membrane fractionation of hybrid poplar microsomes demonstrated that transport activity was localized to the tonoplast- and endomembrane-rich fraction. Differentiating xylem of Japanese cypress exhibited almost identical transport properties, suggesting the involvement of a common endomembrane-associated proton/coniferin antiport mechanism in the lignifying tissues of woody plants, both angiosperms and gymnosperms. PMID:23585651

  8. Modeling aboveground biomass of Tamarix ramosissima in the Arkansas River Basin of Southeastern Colorado, USA

    USGS Publications Warehouse

    Evangelista, P.; Kumar, S.; Stohlgren, T.J.; Crall, A.W.; Newman, G.J.

    2007-01-01

    Predictive models of aboveground biomass of nonnative Tamarix ramosissima of various sizes were developed using destructive sampling techniques on 50 individuals and four 100-m2 plots. Each sample was measured for average height (m) of stems and canopy area (m2) prior to cutting, drying, and weighing. Five competing regression models (P < 0.05) were developed to estimate aboveground biomass of T. ramosissima using average height and/or canopy area measurements and were evaluated using Akaike's Information Criterion corrected for small sample size (AICc). Our best model (AICc = -148.69, ??AICc = 0) successfully predicted T. ramosissima aboveground biomass (R2 = 0.97) and used average height and canopy area as predictors. Our 2nd-best model, using the same predictors, was also successful in predicting aboveground biomass (R2 = 0.97, AICc = -131.71, ??AICc = 16.98). A 3rd model demonstrated high correlation between only aboveground biomass and canopy area (R2 = 0.95), while 2 additional models found high correlations between aboveground biomass and average height measurements only (R2 = 0.90 and 0.70, respectively). These models illustrate how simple field measurements, such as height and canopy area, can be used in allometric relationships to accurately predict aboveground biomass of T. ramosissima. Although a correction factor may be necessary for predictions at larger scales, the models presented will prove useful for many research and management initiatives.

  9. Wavelet analysis for aboveground biomass estimate in temperate deciduous forests

    NASA Astrophysics Data System (ADS)

    Wei, Xiao-Fang

    2008-10-01

    The ever-increasing concentration of anthropogenic greenhouse gases (CO2, CH4, and CFCs) has been identified as a likely (greater than 90% confidence) cause of the observed increase of global mean temperatures since the mid-20th century (IPCC, 2007). The effect of human-induced climate change could be unprecedented and far-reaching. Carbon sequestration into trees and forests is an effective and inexpensive way for mitigating the CO2 level in the atmosphere. Hence, accurate measurement of biomass will be of great importance to global carbon cycle and climate change. This study performed a wavelet-based forest aboveground biomass estimation approach in a temperate deciduous forest, the Hoosier National Forest, in Indiana. Wavelet analysis, specifically two-dimensional discrete wavelet transform (DWT) was applied to ASTER images to obtain wavelet coefficients (WCs), which were correlated with forest inventory data using multiple linear regression analysis to investigate the relationship. Different mother wavelets and level of decomposition were tested. Moreover, vegetation indices, RATIO, normalized difference vegetation index (NDVI), and principal component analyses (PCA) were computed and correlated with field biomass measurements. The results indicate that wavelet coefficients correlate better with field biomass data than vegetation indices. For level one decomposition, the correlation coefficients are 0.3 to 0.5, while 0.1-0.3 for vegetation indices; for level two decomposition, the overall R value increased by 0.2, and for level three, the R value can be increased to 0.6-0.7. Meanwhile, tree per acre and basal area were also examined and correlated with field measurements. This study demonstrates that wavelet-based biomass estimation could be a very promising approach for solving the uncertainty between reflectance value from satellite images and forest biomass and therefore providing better biomass estimation; however, further research is needed for identifying

  10. The major plant-derived cannabinoid Δ(9)-tetrahydrocannabinol promotes hypertrophy and macrophage infiltration in adipose tissue.

    PubMed

    Wong, A; Gunasekaran, N; Hancock, D P; Denyer, G S; Meng, L; Radford, J L; McGregor, I S; Arnold, J C

    2012-02-01

    Synthetic cannabinoid receptor agonists activate lipoprotein lipase and the formation of lipid droplets in cultured adipocytes. Here we extend this work by examining whether Δ(9)-tetrahydrocannabinol (THC), a major plant-derived cannabinoid, increases adipocyte size in vivo. Further, possibly as a consequence of hypertrophy, we hypothesize that THC exposure promotes macrophage infiltration into adipose tissue, an inflammatory state observed in obese individuals. Rats repeatedly exposed to THC in vivo had reduced body weight, fat pad weight, and ingested less food over the drug injection period. However, THC promoted adipocyte hypertrophy that was accompanied by a significant increase in cytosolic phosphoenolpyruvate carboxykinase (PEPCK-C) expression, an enzyme important in packaging triglycerides. We also showed that THC induced macrophage infiltration and increased expression of the inflammatory cytokine tumor necrosis factor alpha (TNF-α) in adipose tissue but did not induce apoptosis as measured by TUNEL staining. That THC increased adipocyte cell size in the absence of greater food intake, body weight and fat provides a unique model to explore mechanisms underlying changes in adipocyte size associated with a mild inflammatory state in fat tissue. PMID:22189757

  11. Tissue specific and abiotic stress regulated transcription of histidine kinases in plants is also influenced by diurnal rhythm.

    PubMed

    Singh, Anupama; Kushwaha, Hemant R; Soni, Praveen; Gupta, Himanshu; Singla-Pareek, Sneh L; Pareek, Ashwani

    2015-01-01

    Two-component system (TCS) is one of the key signal sensing machinery which enables species to sense environmental stimuli. It essentially comprises of three major components, sensory histidine kinase proteins (HKs), histidine phosphotransfer proteins (Hpts), and response regulator proteins (RRs). The members of the TCS family have already been identified in Arabidopsis and rice but the knowledge about their functional indulgence during various abiotic stress conditions remains meager. Current study is an attempt to carry out comprehensive analysis of the expression of TCS members in response to various abiotic stress conditions and in various plant tissues in Arabidopsis and rice using MPSS and publicly available microarray data. The analysis suggests that despite having almost similar number of genes, rice expresses higher number of TCS members during various abiotic stress conditions than Arabidopsis. We found that the TCS machinery is regulated by not only various abiotic stresses, but also by the tissue specificity. Analysis of expression of some representative members of TCS gene family showed their regulation by the diurnal cycle in rice seedlings, thus bringing-in another level of their transcriptional control. Thus, we report a highly complex and tight regulatory network of TCS members, as influenced by the tissue, abiotic stress signal, and diurnal rhythm. The insights on the comparative expression analysis presented in this study may provide crucial leads toward dissection of diverse role(s) of the various TCS family members in Arabidopsis and rice. PMID:26442025

  12. Tissue specific and abiotic stress regulated transcription of histidine kinases in plants is also influenced by diurnal rhythm

    PubMed Central

    Singh, Anupama; Kushwaha, Hemant R.; Soni, Praveen; Gupta, Himanshu; Singla-Pareek, Sneh L.; Pareek, Ashwani

    2015-01-01

    Two-component system (TCS) is one of the key signal sensing machinery which enables species to sense environmental stimuli. It essentially comprises of three major components, sensory histidine kinase proteins (HKs), histidine phosphotransfer proteins (Hpts), and response regulator proteins (RRs). The members of the TCS family have already been identified in Arabidopsis and rice but the knowledge about their functional indulgence during various abiotic stress conditions remains meager. Current study is an attempt to carry out comprehensive analysis of the expression of TCS members in response to various abiotic stress conditions and in various plant tissues in Arabidopsis and rice using MPSS and publicly available microarray data. The analysis suggests that despite having almost similar number of genes, rice expresses higher number of TCS members during various abiotic stress conditions than Arabidopsis. We found that the TCS machinery is regulated by not only various abiotic stresses, but also by the tissue specificity. Analysis of expression of some representative members of TCS gene family showed their regulation by the diurnal cycle in rice seedlings, thus bringing-in another level of their transcriptional control. Thus, we report a highly complex and tight regulatory network of TCS members, as influenced by the tissue, abiotic stress signal, and diurnal rhythm. The insights on the comparative expression analysis presented in this study may provide crucial leads toward dissection of diverse role(s) of the various TCS family members in Arabidopsis and rice. PMID:26442025

  13. Two-Photon Sensing and Imaging of Endogenous Biological Cyanide in Plant Tissues Using Graphene Quantum Dot/Gold Nanoparticle Conjugate.

    PubMed

    Wang, Lili; Zheng, Jing; Yang, Sheng; Wu, Cuichen; Liu, Changhui; Xiao, Yue; Li, Yinhui; Qing, Zhihe; Yang, Ronghua

    2015-09-01

    One main source of cyanide (CN(-)) exposure for mammals is through the plant consumption, and thus, sensitive and selective CN(-) detection in plants tissue is a significant and urgent work. Although various fluorescence probes have been reported for CN(-) in water and mammalian cells, the detection of endogenous biological CN(-) in plant tissue remains to be explored due to the high background signal and large thickness of plant tissue that hamper the effective application of traditional one-photo excitation. To address these issues, we developed a new two-photo excitation (TPE) nanosensor using graphene quantum dots (GQDs)/gold nanoparticle (AuNPs) conjugate for sensing and imaging endogenous biological CN(-). With the benefit of the high quenching efficiency of AuNPs and excellent two-photon properties of GQDs, our sensing system can achieve a low detection limit of 0.52 μM and deeper penetration depth (about 400 μm) without interference from background signals of a complex biological environment, thus realizing sensing and imaging of CN(-) in different types of plant tissues and even monitoring CN(-) removal in food processing. To the best of our knowledge, this is the first time for fluorescent sensing and imaging of CN(-) in plant tissues. Moreover, our design also provides a new model scheme for the development of two-photon fluorescent nanomaterial, which is expected to hold great potential for food processing and safety testing. PMID:26264405

  14. Inducibility of chemical defences by two chewing insect herbivores in pine trees is specific to targeted plant tissue, particular herbivore and defensive trait.

    PubMed

    Moreira, Xoaquín; Lundborg, Lina; Zas, Rafael; Carrillo-Gavilán, Amparo; Borg-Karlson, Anna-Karin; Sampedro, Luis

    2013-10-01

    There is increasing evidence that plants can react to biotic aggressions with highly specific responses. However, few studies have attempted to jointly investigate whether the induction of plant defences is specific to a targeted plant tissue, plant species, herbivore identity, and defensive trait. Here we studied those factors contributing to the specificity of induced defensive responses in two economically important pine species against two chewing insect pest herbivores. Juvenile trees of Pinus pinaster and P. radiata were exposed to herbivory by two major pest threats, the large pine weevil Hylobius abietis (a bark-feeder) and the pine processionary caterpillar Thaumetopoea pityocampa (a folivore). We quantified in two tissues (stem and needles) the constitutive (control plants) and herbivore-induced concentrations of total polyphenolics, volatile and non-volatile resin, as well as the profile of mono- and sesquiterpenes. Stem chewing by the pine weevil increased concentrations of non-volatile resin, volatile monoterpenes, and (marginally) polyphenolics in stem tissues. Weevil feeding also increased the concentration of non-volatile resin and decreased polyphenolics in the needle tissues. Folivory by the caterpillar had no major effects on needle defensive chemistry, but a strong increase in the concentration of polyphenolics in the stem. Interestingly, we found similar patterns for all these above-reported effects in both pine species. These results offer convincing evidence that induced defences are highly specific and may vary depending on the targeted plant tissue, the insect herbivore causing the damage and the considered defensive compound. PMID:23768645

  15. Fluorescence in situ hybridizations (FISH) for the localization of viruses and endosymbiotic bacteria in plant and insect tissues.

    PubMed

    Kliot, Adi; Kontsedalov, Svetlana; Lebedev, Galina; Brumin, Marina; Cathrin, Pakkianathan Britto; Marubayashi, Julio Massaharu; Skaljac, Marisa; Belausov, Eduard; Czosnek, Henryk; Ghanim, Murad

    2014-01-01

    Fluorescence in situ hybridization (FISH) is a name given to a variety of techniques commonly used for visualizing gene transcripts in eukaryotic cells and can be further modified to visualize other components in the cell such as infection with viruses and bacteria. Spatial localization and visualization of viruses and bacteria during the infection process is an essential step that complements expression profiling experiments such as microarrays and RNAseq in response to different stimuli. Understanding the spatiotemporal infections with these agents complements biological experiments aimed at understanding their interaction with cellular components. Several techniques for visualizing viruses and bacteria such as reporter gene systems or immunohistochemical methods are time-consuming, and some are limited to work with model organisms and involve complex methodologies. FISH that targets RNA or DNA species in the cell is a relatively easy and fast method for studying spatiotemporal localization of genes and for diagnostic purposes. This method can be robust and relatively easy to implement when the protocols employ short hybridizing, commercially-purchased probes, which are not expensive. This is particularly robust when sample preparation, fixation, hybridization, and microscopic visualization do not involve complex steps. Here we describe a protocol for localization of bacteria and viruses in insect and plant tissues. The method is based on simple preparation, fixation, and hybridization of insect whole mounts and dissected organs or hand-made plant sections, with 20 base pairs short DNA probes conjugated to fluorescent dyes on their 5' or 3' ends. This protocol has been successfully applied to a number of insect and plant tissues, and can be used to analyze expression of mRNAs or other RNA or DNA species in the cell. PMID:24637389

  16. Application of a novel and automated branched DNA in situ hybridization method for the rapid and sensitive localization of mRNA molecules in plant tissues1

    PubMed Central

    Bowling, Andrew J.; Pence, Heather E.; Church, Jeffrey B.

    2014-01-01

    • Premise of the study: A novel branched DNA detection technology, RNAscope in situ hybridization (ISH), originally developed for use on human clinical and animal tissues, was adapted for use in plant tissue in an attempt to overcome some of the limitations associated with traditional ISH assays. • Methods and Results: Zea mays leaf tissue was formaldehyde fixed and paraffin embedded (FFPE) and then probed with the RNAscope ISH assay for two endogenous genes, phosphoenolpyruvate carboxylase (PEPC) and phosphoenolpyruvate carboxykinase (PEPCK). Results from both manual and automated methods showed tissue- and cell-specific mRNA localization patterns expected from these well-studied genes. • Conclusions: RNAscope ISH is a sensitive method that generates high-quality, easily interpretable results from FFPE plant tissues. Automation of the RNAscope method on the Ventana Discovery Ultra platform allows significant advantages for repeatability, reduction in variability, and flexibility of workflow processes. PMID:25202621

  17. An effective system to produce smoke solutions from dried plant tissue for seed germination studies1

    PubMed Central

    Coons, Janice; Coutant, Nancy; Lawrence, Barbara; Finn, Daniel; Finn, Stephanie

    2014-01-01

    • Premise of the study: An efficient and inexpensive system was developed to produce smoke solutions from plant material to research the influence of water-soluble compounds from smoke on seed germination. • Methods and Results: Smoke solutions (300 mL per batch) were produced by burning small quantities (100–200 g) of dried plant material from a range of species in a bee smoker attached by a heater hose to a side-arm flask. The flask was attached to a vacuum water aspirator, to pull the smoke through the water. The entire apparatus was operated in a laboratory fume hood. • Conclusions: Compared with other smoke solution preparation systems, the system described is easy to assemble and operate, inexpensive to build, and effective at producing smoke solutions from desired species in a small indoor space. Quantitative measurements can be made when using this system, allowing for replication of the process. PMID:25202613

  18. Online, real-time detection of volatile emissions from plant tissue.

    PubMed

    Harren, Frans J M; Cristescu, Simona M

    2013-01-01

    Trace gas monitoring plays an important role in many areas of life sciences ranging from agrotechnology, microbiology, molecular biology, physiology, and phytopathology. In plants, many processes can be followed by their low-concentration gas emission, for compounds such as ethylene, nitric oxide, ethanol or other volatile organic compounds (VOCs). For this, numerous gas-sensing devices are currently available based on various methods. Among them are the online trace gas detection methods; these have attracted much interest in recent years. Laser-based infrared spectroscopy and proton transfer reaction mass spectrometry are the two most widely used methods, thanks to their high sensitivity at the single part per billion level and their response time of seconds. This paper starts with a short description of each method and presents performances within a wide variety of biological applications. Using these methods, the dynamics of trace gases for ethylene, nitric oxide and other VOCs released by plants under different conditions are recorded and analysed under natural conditions. In this way many hypotheses can be tested, revealing the role of the key elements in signalling and action mechanisms in plants. PMID:23429357

  19. Online, real-time detection of volatile emissions from plant tissue

    PubMed Central

    Harren, Frans J. M.; Cristescu, Simona M.

    2013-01-01

    Trace gas monitoring plays an important role in many areas of life sciences ranging from agrotechnology, microbiology, molecular biology, physiology, and phytopathology. In plants, many processes can be followed by their low-concentration gas emission, for compounds such as ethylene, nitric oxide, ethanol or other volatile organic compounds (VOCs). For this, numerous gas-sensing devices are currently available based on various methods. Among them are the online trace gas detection methods; these have attracted much interest in recent years. Laser-based infrared spectroscopy and proton transfer reaction mass spectrometry are the two most widely used methods, thanks to their high sensitivity at the single part per billion level and their response time of seconds. This paper starts with a short description of each method and presents performances within a wide variety of biological applications. Using these methods, the dynamics of trace gases for ethylene, nitric oxide and other VOCs released by plants under different conditions are recorded and analysed under natural conditions. In this way many hypotheses can be tested, revealing the role of the key elements in signalling and action mechanisms in plants. PMID:23429357

  20. Unexpected Behavior of Some Nitric Oxide Modulators under Cadmium Excess in Plant Tissue

    PubMed Central

    Kováčik, Jozef; Babula, Petr; Klejdus, Bořivoj; Hedbavny, Josef; Jarošová, Markéta

    2014-01-01

    Various nitric oxide modulators (NO donors - SNP, GSNO, DEA NONOate and scavengers – PTIO, cPTIO) were tested to highlight the role of NO under Cd excess in various ontogenetic stages of chamomile (Matricaria chamomilla). Surprisingly, compared to Cd alone, SNP and PTIO elevated Cd uptake (confirmed also by PhenGreen staining) but depleted glutathione (partially ascorbic acid) and phytochelatins PC2 and PC3 in both older plants (cultured hydroponically) and seedlings (cultured in deionised water). Despite these anomalous impacts, fluorescence staining of NO and ROS confirmed predictable assumptions and revealed reciprocal changes (decrease in NO but increase in ROS after PTIO addition and the opposite after SNP application). Subsequent tests using alternative modulators and seedlings confirmed changes to NO and ROS after application of GSNO and DEA NONOate as mentioned above for SNP while cPTIO altered only NO level (depletion). On the contrary to SNP and PTIO, GSNO, DEA NONOate and cPTIO did not elevate Cd content and phytochelatins (PC2, PC3) were rather elevated. These data provide evidence that various NO modulators are useful in terms of NO and ROS manipulation but interactions with intact plants affect metal uptake and must therefore be used with caution. In this view, cPTIO and DEA NONOate revealed the less pronounced side impacts and are recommended as suitable NO scavenger/donor in plant physiological studies under Cd excess. PMID:24626462

  1. Potassium (K+) gradients serve as a mobile energy source in plant vascular tissues

    PubMed Central

    Gajdanowicz, Pawel; Michard, Erwan; Sandmann, Michael; Rocha, Marcio; Corrêa, Luiz Gustavo Guedes; Ramírez-Aguilar, Santiago J.; Gomez-Porras, Judith L.; González, Wendy; Thibaud, Jean-Baptiste; van Dongen, Joost T.; Dreyer, Ingo

    2011-01-01

    The essential mineral nutrient potassium (K+) is the most important inorganic cation for plants and is recognized as a limiting factor for crop yield and quality. Nonetheless, it is only partially understood how K+ contributes to plant productivity. K+ is used as a major active solute to maintain turgor and to drive irreversible and reversible changes in cell volume. K+ also plays an important role in numerous metabolic processes, for example, by serving as an essential cofactor of enzymes. Here, we provide evidence for an additional, previously unrecognized role of K+ in plant growth. By combining diverse experimental approaches with computational cell simulation, we show that K+ circulating in the phloem serves as a decentralized energy storage that can be used to overcome local energy limitations. Posttranslational modification of the phloem-expressed Arabidopsis K+ channel AKT2 taps this “potassium battery,” which then efficiently assists the plasma membrane H+-ATPase in energizing the transmembrane phloem (re)loading processes. PMID:21187374

  2. Airport, air base benefit from switch to aboveground tanks

    SciTech Connect

    1995-10-01

    The Environmental Protection Agency requires that by the end of 1998 all underground fuel tanks must comply with requirements established for tanks installed after Dec. 22, 1988. To comply with federal and state regulations, authorities at Mansfield (Mass.) Municipal Airport decided during a recent reconstruction effort to replace several 46-year-old underground fuel tanks with an 8,000-gallon, aboveground tank. After researching several types of tanks and weighing recommendations from the airport`s fueling company, officials chose to install a lightweight, double-walled tank from Aero-Power Unitized Fueler Inc., Smithtown, NY. The Fireguard{trademark} tank has a concrete-insulated lining between its two walls that can absorb aviation fuel in case of a pool fire. An outer steel wall provides secondary containment, protecting the insulating material, and resists cracking and spalling. Dobbins Air Reserve Base in Georgia recently installed two 2,000-gallon Fireguard tanks to contain diesel and unleaded fuel for a new military-vehicle refueling station.

  3. Regional Mapping, Modelling, and Monitoring of Tree Aboveground Biomass Carbon

    NASA Astrophysics Data System (ADS)

    Hudak, Andrew

    2016-04-01

    Airborne lidar collections are preferred for mapping aboveground biomass carbon (AGBC), while historical Landsat imagery are preferred for monitoring decadal scale forest cover change. Our modelling approach tracks AGBC change regionally using Landsat time series metrics; training areas are defined by airborne lidar extents within which AGBC is accurately mapped with high confidence. Geospatial topographic and climate layers are also included in the predictive model. Validation is accomplished using systematically sampled Forest Inventory and Analysis (FIA) plot data that have been independently collected, processed and summarized at the county level. Our goal is to demonstrate that spatially and temporally aggregated annual AGBC map predictions show no bias when compared to annual county-level summaries across the Northwest USA. A prominent source of bias is trees outside forest; much of the more arid portions of our study area meet the FIA definition of non-forest because the tree cover does not exceed their minimum tree cover threshold. We employ detailed tree cover maps derived from high-resolution aerial imagery to extend our AGBC predictions into non-forest areas. We also employ Landsat-derived annual disturbance maps into our mapped AGBC predictions prior to aggregation and validation.

  4. [Dry matter accumulation in rice aboveground part: quantitative simulation].

    PubMed

    Li, Yan-Da; Tang, Liang; Chen, Qing-Chun; Zhang, Yu-Ping; Cao, Wei-Xing; Zhu, Yan

    2010-06-01

    A field experiment with four rice (Oryza sativa L.) cultivars and different nitrogen application rates was conducted, with the dry matter accumulation (DMA) in the cultivars aboveground part measured at their main growth stages. The dynamic model of relative dry matter accumulation (RDMA) was established with the normalized DMA and TEP (product of thermal effectiveness and PAR) from emergence to maturity, and the temporal characteristics of DMA changes was quantitatively analyzed based on the RDMA model. The dynamic changes of the RDMA could be well described with Richards equation, i. e., RDMA = 1.0157/(1 +e(3.6329-7.5907xRTEP)) 1/0.5574 (r = 0.9938). The model was validated with independent field experiment datasets, involving different eco-sites, cultivars, and nitrogen application rates. The RMSE (root mean square error) between the simulated and observed values of DMA at varied RTEP was 0.86 t x hm(-2). According to the two inflexion points of dry matter accumulation rate equation, the whole process of dry matter accumulation could be divided into early, middle, and late phases. The maximum dry matter accumulation rate (AR(max)), relative TEP at AR(max), and relative dry matter accumulation at AR(max) were found to be 2.24, 0.56, and 0.46, respectively. PMID:20873627

  5. Analysis of laser-induced fluorescence spectra of in vitro plant tissue cultures.

    PubMed

    Muñoz-Muñoz, Ana Celia; Gutiérrez-Pulido, Humberto; Rodríguez-Domínguez, José Manuel; Gutiérrez-Mora, Antonia; Rodríguez-Garay, Benjamín; Cervantes-Martínez, Jesús

    2007-04-10

    We demonstrate the effectiveness of laser-induced fluorescence (LIF) for monitoring the development and stress detection of in vitro tissue cultures in a nondestructive and noninvasive way. The changes in LIF spectra caused by the induction of organogenesis, the increase of the F690/F740 ratio as a result of the stress originated in the organogenic explants due to shoot emergence, and the relationship between fluorescence spectra and shoot development were detected by LIF through closed containers of Saintpaulia ionantha. PMID:17384731

  6. Micro-scaled high-throughput digestion of plant tissue samples for multi-elemental analysis

    PubMed Central

    Hansen, Thomas H; Laursen, Kristian H; Persson, Daniel P; Pedas, Pai; Husted, Søren; Schjoerring, Jan K

    2009-01-01

    Background Quantitative multi-elemental analysis by inductively coupled plasma (ICP) spectrometry depends on a complete digestion of solid samples. However, fast and thorough sample digestion is a challenging analytical task which constitutes a bottleneck in modern multi-elemental analysis. Additional obstacles may be that sample quantities are limited and elemental concentrations low. In such cases, digestion in small volumes with minimum dilution and contamination is required in order to obtain high accuracy data. Results We have developed a micro-scaled microwave digestion procedure and optimized it for accurate elemental profiling of plant materials (1-20 mg dry weight). A commercially available 64-position rotor with 5 ml disposable glass vials, originally designed for microwave-based parallel organic synthesis, was used as a platform for the digestion. The novel micro-scaled method was successfully validated by the use of various certified reference materials (CRM) with matrices rich in starch, lipid or protein. When the micro-scaled digestion procedure was applied on single rice grains or small batches of Arabidopsis seeds (1 mg, corresponding to approximately 50 seeds), the obtained elemental profiles closely matched those obtained by conventional analysis using digestion in large volume vessels. Accumulated elemental contents derived from separate analyses of rice grain fractions (aleurone, embryo and endosperm) closely matched the total content obtained by analysis of the whole rice grain. Conclusion A high-throughput micro-scaled method has been developed which enables digestion of small quantities of plant samples for subsequent elemental profiling by ICP-spectrometry. The method constitutes a valuable tool for screening of mutants and transformants. In addition, the method facilitates studies of the distribution of essential trace elements between and within plant organs which is relevant for, e.g., breeding programmes aiming at improvement of the

  7. Breaking dogmas: the plant vascular pathogen Xanthomonas albilineans is able to invade non-vascular tissues despite its reduced genome

    PubMed Central

    Mensi, Imène; Vernerey, Marie-Stéphanie; Gargani, Daniel; Nicole, Michel; Rott, Philippe

    2014-01-01

    Xanthomonas albilineans, the causal agent of sugarcane leaf scald, is missing the Hrp type III secretion system that is used by many Gram-negative bacteria to colonize their host. Until now, this pathogen was considered as strictly limited to the xylem of sugarcane. We used confocal laser scanning microscopy, immunocytochemistry and transmission electron microscopy (TEM) to investigate the localization of X. albilineans in diseased sugarcane. Sugarcane plants were inoculated with strains of the pathogen labelled with a green fluorescent protein. Confocal microscopy observations of symptomatic leaves confirmed the presence of the pathogen in the protoxylem and metaxylem; however, X. albilineans was also observed in phloem, parenchyma and bulliform cells of the infected leaves. Similarly, vascular bundles of infected sugarcane stalks were invaded by X. albilineans. Surprisingly, the pathogen was also observed in apparently intact storage cells of the stalk and in intercellular spaces between these cells. Most of these observations made by confocal microscopy were confirmed by TEM. The pathogen exits the xylem following cell wall and middle lamellae degradation, thus creating openings to reach parenchyma cells. This is the first description of a plant pathogenic vascular bacterium invading apparently intact non-vascular plant tissues and multiplying in parenchyma cells. PMID:24522883

  8. Plant abiotic stress diagnostic by laser induced chlorophyll fluorescence spectral analysis of in vivo leaf tissue of biofuel species

    NASA Astrophysics Data System (ADS)

    Gouveia-Neto, Artur S.; Silva, Elias A., Jr.; Costa, Ernande B.; Bueno, Luciano A.; Silva, Luciana M. H.; Granja, Manuela M. C.; Medeiros, Maria J. L.; Câmara, Terezinha J. R.; Willadino, Lilia G.

    2010-02-01

    Laser induced fluorescence is exploited to evaluate the effect of abiotic stresses upon the evolution and characteristics of in vivo chlorophyll emission spectra of leaves tissues of brazilian biofuel plants species(Saccharum officinarum and Jatropha curcas). The chlorophyll fluorescence spectra of 20 min predarkened intact leaves were studied employing several excitation wavelengths in the UV-VIS spectral region. Red(Fr) and far-red (FFr) chlorophyll fluorescence emission signals around 685 nm and 735 nm, respectively, were analyzed as a function of the stress intensity and the time of illumination(Kautsky effect). The Chl fluorescence ratio Fr/FFr which is a valuable nondestructive indicator of the chlorophyll content of leaves was investigated during a period of time of 30 days. The dependence of the Chl fluorescence ratio Fr/FFr upon the intensity of the abiotic stress(salinity) was examined. The results indicated that the salinity plays a major hole in the chlorophyll concentration of leaves in both plants spieces, with a significant reduction in the chlorophyll content for NaCl concentrations in the 25 - 200 mM range. The laser induced chlorophyll fluorescence analysis allowed detection of damage caused by salinity in the early stages of the plants growing process, and can be used as an early-warning indicator of salinity stress

  9. A novel microsurgery method for intact plant tissue at the single cell level using ArF excimer laser microprojection.

    PubMed

    Kajiyama, Shin'ichiro; Shoji, Takeshi; Okuda, Shinya; Izumi, Yoshihiro; Fukusaki, Ei-ichiro; Kobayashi, Akio

    2006-02-01

    A novel microsurgery technique for the partial removal of rigid cell-walls in intact plant tissue is established. Using a size-variable slit, an ArF excimer laser was microprojected on the surface of the targeted cell, and this method enabled the area- and depth-controllable processing of the cortical structure of plant cells including the cuticle and cell wall layer. In epidermal cells of all tested plants, viabilities of more than 90% were retained 24 h after irradiation. Scanning electron microscope (SEM) observation revealed that the cuticle layer of the irradiated region was completely ablated, and the cellulose microfibrils of the secondary cell wall were partially removed; furthermore, 4 days after laser treatment, the regeneration of cell wall fibrils was observed. As a model experiment, the transient expression of synthetic green fluorescent protein (sGFP) was performed by the microinjection of cauliflower mosaic virus (CMV) 35S promoter-derived sGFP gene through an "aperture" in the treated cell surface. Moreover, micron-sized fluorescent beads were successfully introduced by the same method into the onion cells indicating that this method can be used to introduce foreign materials as large as organelles. PMID:16193516

  10. Electron Tomography of Cryo-Immobilized Plant Tissue: A Novel Approach to Studying 3D Macromolecular Architecture of Mature Plant Cell Walls In Situ

    PubMed Central

    Sarkar, Purbasha; Bosneaga, Elena; Yap, Edgar G.; Das, Jyotirmoy; Tsai, Wen-Ting; Cabal, Angelo; Neuhaus, Erica; Maji, Dolonchampa; Kumar, Shailabh; Joo, Michael; Yakovlev, Sergey; Csencsits, Roseann; Yu, Zeyun; Bajaj, Chandrajit; Downing, Kenneth H.; Auer, Manfred

    2014-01-01

    Cost-effective production of lignocellulosic biofuel requires efficient breakdown of cell walls present in plant biomass to retrieve the wall polysaccharides for fermentation. In-depth knowledge of plant cell wall composition is therefore essential for improving the fuel production process. The precise spatial three-dimensional (3D) organization of cellulose, hemicellulose, pectin and lignin within plant cell walls remains unclear to date since the microscopy techniques used so far have been limited to two-dimensional, topographic or low-resolution imaging, or required isolation or chemical extraction of the cell walls. In this paper we demonstrate that by cryo-immobilizing fresh tissue, then either cryo-sectioning or freeze-substituting and resin embedding, followed by cryo- or room temperature (RT) electron tomography, respectively, we can visualize previously unseen details of plant cell wall architecture in 3D, at macromolecular resolution (∼2 nm), and in near-native state. Qualitative and quantitative analyses showed that wall organization of cryo-immobilized samples were preserved remarkably better than conventionally prepared samples that suffer substantial extraction. Lignin-less primary cell walls were well preserved in both self-pressurized rapidly frozen (SPRF), cryo-sectioned samples as well as high-pressure frozen, freeze-substituted and resin embedded (HPF-FS-resin) samples. Lignin-rich secondary cell walls appeared featureless in HPF-FS-resin sections presumably due to poor stain penetration, but their macromolecular features could be visualized in unprecedented details in our cryo-sections. While cryo-tomography of vitreous tissue sections is currently proving to be instrumental in developing 3D models of lignin-rich secondary cell walls, here we confirm that the technically easier method of RT-tomography of HPF-FS-resin sections could be used immediately for routine study of low-lignin cell walls. As a proof of principle, we characterized the

  11. Electron tomography of cryo-immobilized plant tissue: a novel approach to studying 3D macromolecular architecture of mature plant cell walls in situ.

    PubMed

    Sarkar, Purbasha; Bosneaga, Elena; Yap, Edgar G; Das, Jyotirmoy; Tsai, Wen-Ting; Cabal, Angelo; Neuhaus, Erica; Maji, Dolonchampa; Kumar, Shailabh; Joo, Michael; Yakovlev, Sergey; Csencsits, Roseann; Yu, Zeyun; Bajaj, Chandrajit; Downing, Kenneth H; Auer, Manfred

    2014-01-01

    Cost-effective production of lignocellulosic biofuel requires efficient breakdown of cell walls present in plant biomass to retrieve the wall polysaccharides for fermentation. In-depth knowledge of plant cell wall composition is therefore essential for improving the fuel production process. The precise spatial three-dimensional (3D) organization of cellulose, hemicellulose, pectin and lignin within plant cell walls remains unclear to date since the microscopy techniques used so far have been limited to two-dimensional, topographic or low-resolution imaging, or required isolation or chemical extraction of the cell walls. In this paper we demonstrate that by cryo-immobilizing fresh tissue, then either cryo-sectioning or freeze-substituting and resin embedding, followed by cryo- or room temperature (RT) electron tomography, respectively, we can visualize previously unseen details of plant cell wall architecture in 3D, at macromolecular resolution (∼ 2 nm), and in near-native state. Qualitative and quantitative analyses showed that wall organization of cryo-immobilized samples were preserved remarkably better than conventionally prepared samples that suffer substantial extraction. Lignin-less primary cell walls were well preserved in both self-pressurized rapidly frozen (SPRF), cryo-sectioned samples as well as high-pressure frozen, freeze-substituted and resin embedded (HPF-FS-resin) samples. Lignin-rich secondary cell walls appeared featureless in HPF-FS-resin sections presumably due to poor stain penetration, but their macromolecular features could be visualized in unprecedented details in our cryo-sections. While cryo-tomography of vitreous tissue sections is currently proving to be instrumental in developing 3D models of lignin-rich secondary cell walls, here we confirm that the technically easier method of RT-tomography of HPF-FS-resin sections could be used immediately for routine study of low-lignin cell walls. As a proof of principle, we characterized the

  12. Improved Plant-based Production of E1 endoglucanase Using Potato: Expression Optimization and Tissue Targeting

    SciTech Connect

    Dai, Ziyu; Hooker, Brian S.; Anderson, Daniel B.; Thomas, Steven R.

    2000-06-01

    Optimization of Acidothermus cellulolyticus endoglucanase (E1) gene expression in transgenic potato (Solanum tuberosum L.) was examined in this study, where the E1 coding sequence was transcribed under control of a leaf specific promoter (tomato RbcS-3C) or the Mac promoter (a hybrid promoter of mannopine synthase promoter and cauliflower mosaic virus 35S promoter enhancer region). Average E1 activity in leaf extracts of potato transformants, in which E1 protein was targeted by a chloroplast signal peptide and an apoplast signal peptide were much higher than those by an E1 native signal peptide and a vacuole signal peptide. E1 protein accumulated up to 2.6% of total leaf soluble protein, where E1 gene was under control of the RbcS-3C promoter, alfalfa mosaic virus 5-untranslated leader, and RbcS-2A signal peptide. E1 protein production, based on average E1 activity and E1 protein accumulation in leaf extracts, is higher in potato than those measured previously in transgenic tobacco bearing the same transgene constructs. Comparisons of E1 activity, protein accumulation, and relative mRNA levels showed that E1 expression under control of tomato RbcS-3C promoter was specifically localized in leaf tissues, while E1 gene was expressed in both leaf and tuber tissues under control of Mac promoter. This suggests dual-crop applications in which potato vines serve as enzyme production `bioreactors' while tubers are preserved for culinary applications.

  13. A Comparison of the Activation Enthalpies for Ionic Conduction in Animal and Plant Tissue

    NASA Astrophysics Data System (ADS)

    Hart, Francis X.

    1997-11-01

    The electrical properties of biological materials are determined by the transport of ions. There are two stages in the transport of an ion along a surface, such as a cell membrane: ``detrapping'' of the ion from a binding site and (2) ``hopping'' of the freed ion from site to site. An activation enthalpy can be determined for each stage by measuring the impedance spectrum of the tissue over a range of temperatures. A Hewlett Packard 4192A Low Frequency Impedance Analyzer was used to measure the impedance spectra of apples and of crayfish tail muscle over a range of temperatures from about 15^oC to 35^oC. At each temperature a complex-valued, non-linear, least-squares fit of the impedance data was made to a three-component circuit model. From the fitted model values the low frequency tissue conductivity and the high frequency power-law exponent and prefactor were obtained. Arrhenius plots yielded separate activation enthalpies for the detrapping (Hf) and hopping (Hm). For both apples and crayfish Hf is on the order of kT (0.025 eV) whereas Hm is on the order of 0.15 eV.

  14. Effect of calcium silicate slag application on radium-226 concentrations in plant tissues

    SciTech Connect

    Mortvedt, J.J.

    1986-01-01

    A greenhouse pot experiment was conducted to determine if plants absorb Ra from slag applied to soil. Slag at rates equivalent to 0 and 22 mt/ha was mixed with Mountview silt loam (Typic Paleudults) limed to pH 5.8 and 7.2. Three clippings each of fescue (Festuca arundiancea Schreb.), and Swiss chard (Beta vulgaris L.), and one harvest of wheat (Triticum aestivum L.) for grain and straw were grown on separate series of treated soil, and plant samples were analyzed for radioactivity due to /sup 226/Ra uptake. Samples of sugarcane (Saccharum officinarum L.) forage and extracted juice from field experiments in Florida testing this slage as a Si source also were analyzed for radioactivity. Dry forage yields of fescue and wheat were not affected by slag applications, but those of Swiss chard were somewhat higher on slag-treated soil at pH 5.8. Wheat grain and straw yields were higher on soil at pH 7.2 than at pH 5.8 regardless of slag treatment. Uptake of /sup 226/Ra by fescue forage and wheat grain and straw was not affected by slag application. Concentrations of /sup 226/Ra were similar in forage and extracted juice from untreated sugarcane or that treated with slag at rates up to 5.6 mt/ha. These results suggest that plant uptake of radionuclides is negligible from calcium silicate slag applied at the recommended rates for liming acid soils or as a source of Si for sugarcane.

  15. Phosphatidylinositol(4,5)bisphosphate and phosphatidylinositol(4)phosphate in plant tissues. [Pisum sativum

    SciTech Connect

    Irvine, R.F.; Letcher, A.J.; Lander, D.J. ); Dawson, A.P. ); Musgrave, A. ); Drobak, B.K. )

    1989-03-01

    Pea (Pisum sativum) leaf discs or swimming suspensions of Chlamydomonas eugametos were radiolabeled with ({sup 3}H)myo-inositol or ({sup 32}P)Pi and the lipids were extracted, deacylated, and their glycerol moieties removed. The resulting inositol trisphosphate and bisphosphate fractions were examined by periodate degradation, reduction and dephosphorylation, or by incubation with human red cell membranes. Their likely structures were identified as D-myo-inositol(1,4,5)trisphosphate and D-myo-inositol(1,4,)-bisphosphate. It is concluded that plants contain phosphatidylinositol(4)phosphate and phosphatidylinositol(4,5)bisphosphate; no other polyphosphoinositides were detected.

  16. Dryland Wheat Domestication Changed the Development of Aboveground Architecture for a Well-Structured Canopy

    PubMed Central

    Li, Pu-Fang; Cheng, Zheng-Guo; Ma, Bao-Luo; Palta, Jairo A.; Kong, Hai-Yan; Mo, Fei; Wang, Jian-Yong; Zhu, Ying; Lv, Guang-Chao; Batool, Asfa; Bai, Xue; Li, Feng-Min; Xiong, You-Cai

    2014-01-01

    We examined three different-ploidy wheat species to elucidate the development of aboveground architecture and its domesticated mechanism under environment-controlled field conditions. Architecture parameters including leaf, stem, spike and canopy morphology were measured together with biomass allocation, leaf net photosynthetic rate and instantaneous water use efficiency (WUEi). Canopy biomass density was decreased from diploid to tetraploid wheat, but increased to maximum in hexaploid wheat. Population yield in hexaploid wheat was higher than in diploid wheat, but the population fitness and individual competition ability was higher in diploid wheats. Plant architecture was modified from a compact type in diploid wheats to an incompact type in tetraploid wheats, and then to a more compact type of hexaploid wheats. Biomass accumulation, population yield, harvest index and the seed to leaf ratio increased from diploid to tetraploid and hexaploid, associated with heavier specific internode weight and greater canopy biomass density in hexaploid and tetraploid than in diploid wheat. Leaf photosynthetic rate and WUEi were decreased from diploid to tetraploid and increased from tetraploid to hexaploid due to more compact leaf type in hexaploid and diploid than in tetraploid. Grain yield formation and WUEi were closely associated with spatial stance of leaves and stems. We conclude that the ideotype of dryland wheats could be based on spatial reconstruction of leaf type and further exertion of leaf photosynthetic rate. PMID:25181037

  17. Does the aboveground herbivore assemblage influence soil bacterial community composition and richness in subalpine grasslands?

    PubMed

    Hodel, Melanie; Schütz, Martin; Vandegehuchte, Martijn L; Frey, Beat; Albrecht, Matthias; Busse, Matt D; Risch, Anita C

    2014-10-01

    Grassland ecosystems support large communities of aboveground herbivores that are known to directly and indirectly affect belowground properties such as the microbial community composition, richness, or biomass. Even though multiple species of functionally different herbivores coexist in grassland ecosystems, most studies have only considered the impact of a single group, i.e., large ungulates (mostly domestic livestock) on microbial communities. Thus, we investigated how the exclusion of four groups of functionally different herbivores affects bacterial community composition, richness, and biomass in two vegetation types with different grazing histories. We progressively excluded large, medium, and small mammals as well as invertebrate herbivores using exclosures at 18 subalpine grassland sites (9 per vegetation type). We assessed the bacterial community composition using terminal restriction fragment length polymorphism (T-RFLP) at each site and exclosure type during three consecutive growing seasons (2009-2011) for rhizosphere and mineral soil separately. In addition, we determined microbial biomass carbon (MBC), root biomass, plant carbon:nitrogen ratio, soil temperature, and soil moisture. Even though several of these variables were affected by herbivore exclusion and vegetation type, against our expectations, bacterial community composition, richness, or MBC were not. Yet, bacterial communities strongly differed between the three growing seasons as well as to some extent between our study sites. Thus, our study indicates that the spatiotemporal variability in soil microclimate has much stronger effects on the soil bacterial communities than the grazing regime or the composition of the vegetation in this high-elevation ecosystem. PMID:24889285

  18. Estimating aboveground biomass in interior Alaska with Landsat data and field measurements

    USGS Publications Warehouse

    Ji, Lei; Wylie, Bruce K.; Nossov, Dana R.; Peterson, Birgit; Waldrop, Mark P.; McFarland, Jack W.; Rover, Jennifer R.; Hollingsworth, Teresa N.

    2012-01-01

    Terrestrial plant biomass is a key biophysical parameter required for understanding ecological systems in Alaska. An accurate estimation of biomass at a regional scale provides an important data input for ecological modeling in this region. In this study, we created an aboveground biomass (AGB) map at 30-m resolution for the Yukon Flats ecoregion of interior Alaska using Landsat data and field measurements. Tree, shrub, and herbaceous AGB data in both live and dead forms were collected in summers and autumns of 2009 and 2010. Using the Landsat-derived spectral variables and the field AGB data, we generated a regression model and applied this model to map AGB for the ecoregion. A 3-fold cross-validation indicated that the AGB estimates had a mean absolute error of 21.8 Mg/ha and a mean bias error of 5.2 Mg/ha. Additionally, we validated the mapping results using an airborne lidar dataset acquired for a portion of the ecoregion. We found a significant relationship between the lidar-derived canopy height and the Landsat-derived AGB (R2 = 0.40). The AGB map showed that 90% of the ecoregion had AGB values ranging from 10 Mg/ha to 134 Mg/ha. Vegetation types and fires were the primary factors controlling the spatial AGB patterns in this ecoregion.

  19. Remote sensing of aboveground biomass and annual net aerial primary productivity in tidal wetlands

    SciTech Connect

    Hardisky, M.A.

    1983-01-01

    A technique was investigated for estimating biomass and net aerial primary productivity (NAPP) in Delaware tidal marshes from spectral data, describing marsh vegetation canopies. Spectral radiance data were collected with hand-held radiometers from the ground and from low altitude aircraft. Spectral wavebands corresponding to Landsat 4 thematic mapper bands 3, 4 and 5 and multispectral scanner bands 5 and 7 were employed. Spectral data, expressed as index values, were substituted into simple regression models to nondestructively compute total aboveground biomass. Dead biomass, salt crystals on plant leaves and soil background reflectance, all attenuated the spectral radiance index values. A large spectral contribution from any one of these canopy components caused an underestimate of live biomass. Biomass and annual NAPP of a S. alterniflora dominated salt marsh was estimated by traditional harvesting techniques and from ground-gathered spectral radiance data. The live and dead standing crop biomass estimates computed from spectral data were usually not significantly different from harvest biomass estimates. Spectral estimates of NAPP were usually within 10% of NAPP estimates calculated from harvest data. August live standing crop biomass estimates computed from ground-gathered spectral data for a tidal brackish marsh were generally within 10% of harvest estimates. Live biomass estimates computed from spectral data gathered from a low altitude aircraft were equally similar to harvest biomass estimates. The remote sensing technique holds much promise for rapid and accurate estimates of biomass and NAPP in tidal marshes.

  20. Genotype, development and tissue-derived variation of cell-wall properties in the lignocellulosic energy crop Miscanthus

    PubMed Central

    da Costa, Ricardo M. F.; Lee, Scott J.; Allison, Gordon G.; Hazen, Samuel P.; Winters, Ana; Bosch, Maurice

    2014-01-01

    Background and Aims Species and hybrids of the genus Miscanthus contain attributes that make them front-runners among current selections of dedicated bioenergy crops. A key trait for plant biomass conversion to biofuels and biomaterials is cell-wall quality; however, knowledge of cell-wall composition and biology in Miscanthus species is limited. This study presents data on cell-wall compositional changes as a function of development and tissue type across selected genotypes, and considers implications for the development of miscanthus as a sustainable and renewable bioenergy feedstock. Methods Cell-wall biomass was analysed for 25 genotypes, considering different developmental stages and stem vs. leaf compositional variability, by Fourier transform mid-infrared spectroscopy and lignin determination. In addition, a Clostridium phytofermentans bioassay was used to assess cell-wall digestibility and conversion to ethanol. Key Results Important cell-wall compositional differences between miscanthus stem and leaf samples were found to be predominantly associated with structural carbohydrates. Lignin content increased as plants matured and was higher in stem tissues. Although stem lignin concentration correlated inversely with ethanol production, no such correlation was observed for leaves. Leaf tissue contributed significantly to total above-ground biomass at all stages, although the extent of this contribution was genotype-dependent. Conclusions It is hypothesized that divergent carbohydrate compositions and modifications in stem and leaf tissues are major determinants for observed differences in cell-wall quality. The findings indicate that improvement of lignocellulosic feedstocks should encompass tissue-dependent variation as it affects amenability to biological conversion. For gene–trait associations relating to cell-wall quality, the data support the separate examination of leaf and stem composition, as tissue-specific traits may be masked by considering only

  1. Coupling aboveground and belowground activities using short term fluctuations in 13C composition of soil respiration

    NASA Astrophysics Data System (ADS)

    Epron, D.; Parent, F.; Grossiord, C.; Plain, C.; Longdoz, B.; Granier, A.

    2011-12-01

    There is a growing amount of evidence that belowground processes in forest ecosystems are tightly coupled to aboveground activities. Soil CO2 efflux, the largest flux of CO2 to the atmosphere, is dominated by root respiration and by respiration of microorganisms that find the carbohydrates required to fulfil their energetic costs in the rhizosphere. A close coupling between aboveground photosynthetic activity and soil CO2 efflux is therefore expected. The isotopic signature of photosynthates varies with time because photosynthetic carbon isotope discrimination is dynamically controlled by environmental factors. This temporal variation of δ13C of photosynthate is thought to be transferred along the tree-soil continuum and it will be retrieved in soil CO2 efflux after a time lag that reflects the velocity of carbon transport from canopy to belowground. However, isotopic signature of soil CO2 efflux is not solely affected by photosynthetic carbon discrimination, bur also by post photosynthetic fractionation, and especially by fractionation processes affecting CO2 during the transport from soil layers to surface. Tunable diode laser spectrometry is a useful tool to quantify short-term variation in δ13C of soil CO2 efflux and of CO2 in the soil atmosphere. We set up hydrophobic tubes to measure the vertical profile of soil CO2 concentration and its δ13C composition in a temperate beech forest, and we monitored simultaneously δ13C of trunk and soil CO2 efflux, δ13C of phloem exudate and δ13C of leaf sugars. We evidenced that temporal changes in δ13C of soil CO2 and soil CO2 efflux reflected changes in environmental conditions that affect photosynthetic discrimination and that soil CO2 was 4.4% enriched compared to soil CO2 efflux according to diffusion fractionation. However, this close coupling can be disrupted when advective transport of CO2 took place. We also reported evidences that temporal variations in the isotopic composition of soil CO2 efflux reflect

  2. Assessment of a 1H high-resolution magic angle spinning NMR spectroscopy procedure for free sugars quantification in intact plant tissue.

    PubMed

    Delgado-Goñi, Teresa; Campo, Sonia; Martín-Sitjar, Juana; Cabañas, Miquel E; San Segundo, Blanca; Arús, Carles

    2013-08-01

    In most plants, sucrose is the primary product of photosynthesis, the transport form of assimilated carbon, and also one of the main factors determining sweetness in fresh fruits. Traditional methods for sugar quantification (mainly sucrose, glucose and fructose) require obtaining crude plant extracts, which sometimes involve substantial sample manipulation, making the process time-consuming and increasing the risk of sample degradation. Here, we describe and validate a fast method to determine sugar content in intact plant tissue by using high-resolution magic angle spinning nuclear magnetic resonance spectroscopy (HR-MAS NMR). The HR-MAS NMR method was used for quantifying sucrose, glucose and fructose in mesocarp tissues from melon fruits (Cucumis melo var. reticulatus and Cucumis melo var. cantalupensis). The resulting sugar content varied among individual melons, ranging from 1.4 to 7.3 g of sucrose, 0.4-2.5 g of glucose; and 0.73-2.83 g of fructose (values per 100 g fw). These values were in agreement with those described in the literature for melon fruit tissue, and no significant differences were found when comparing them with those obtained using the traditional, enzymatic procedure, on melon tissue extracts. The HR-MAS NMR method offers a fast (usually <30 min) and sensitive method for sugar quantification in intact plant tissues, it requires a small amount of tissue (typically 50 mg fw) and avoids the interferences and risks associated with obtaining plant extracts. Furthermore, this method might also allow the quantification of additional metabolites detectable in the plant tissue NMR spectrum. PMID:23824526

  3. Aboveground and belowground responses to nutrient additions and herbivore exclusion in Arctic tundra ecosystems in northern Alaska

    NASA Astrophysics Data System (ADS)

    Moore, J. C.; Gough, L.; Simpson, R.; Johnson, D. R.

    2011-12-01

    The Arctic has experienced significant increased regional warming over the past 30 years. Warming generally increases tundra soil nutrient availability by creating a more favorable environment for plant growth, decomposition and nutrient mineralization. Aboveground there has been a "greening" of the Arctic with increased net primary productivity (NPP), and an increase in woody vegetation. Concurrent with the changes aboveground has been an increase in root growth at lower depths and a loss of soil organic C (40 -100 g C m-2 yr-1). Given that arctic soils contain 14% of the global soil C pool, understanding the mechanisms behind shifts of this magnitude that are changing arctic soils from a net sink to a net source of atmospheric C is critical. We took an integrated multi-trophic level approach to examine how altering soil nutrients and mammalian herbivore activity affects vegetation, soil fauna, and microbial communities as well as soil physical characteristics in moist acidic (MAT) and dry heath (DH) tundra. Our work was conducted at the Arctic LTER site in northern Alaska. We sampled the nutrient (controls and annual N+P additions) and herbivore (controls and exclosures) manipulations established in 1996 after 10 years of treatment. Models that incorporated the biomass estimates from the field were used to characterize the trophic structure of the belowground food web and to estimate carbon flux among soil organisms and C-mineralization rates. Both MAT and DH exhibited significant increases in NPP and root growth and changes in vegetation structure with transitions from a mixed community to deciduous shrubs in MAT and from lichens to grasses and shrubs in DH, with nutrient additions and herbivore exclosures. Belowground responses to the treatments were dependent on ecosystem type, but exposed alterations in trophic structure that included changes in microbial biomass, the establishment of microbivorous enchytreaids, increases in root-feeding nematodes, and

  4. Antimony (SbIII) reduces growth, declines photosynthesis, and modifies leaf tissue anatomy in sunflower (Helianthus annuus L.).

    PubMed

    Vaculík, Marek; Mrázová, Anna; Lux, Alexander

    2015-12-01

    The role of antimony (Sb)--a non-essential trace metalloid--in physiological processes running in crops is still poorly understood. Present paper describes the effect of Sb tartrate (SbIII) on growth, Sb uptake, photosynthesis, photosynthetic pigments, and leaf tissue organization in young sunflower plants grown in hydroponics. We found that growth of below- and aboveground part was reduced with increasing concentration of Sb in the medium. Although Sb was mostly taken up by sunflower roots and only small part (1-2%) was translocated to the shoots, decline in photosynthesis, transpiration, and decreased content of photosynthetic pigments were observed. This indicates that despite relatively low mobility of Sb in root-shoot system, Sb in shoot noticeably modifies physiological status and reduced plant growth. Additionally, leaf anatomical changes indicated that Sb reduced the size of intercellular spaces and made leaf tissue more compact. PMID:26194244

  5. TECHNICAL BASIS REPORT FOR LARGE FIRE ACCIDENTS INVOLVING ABOVEGROUND TANKS & VESSELS

    SciTech Connect

    MARCHESE, A.R.

    2005-03-03

    This document analyzes large fire accidents involving aboveground tanks and vessels during Demonstration Bulk Vitrification System (DBVS) operations. The fire accident scenarios are consistent with RPP-22461,''Preliminary Fire Hazard Analysis (PFHA) for DBVS''. The radiological and toxicological consequences are determined for a wide spectrum of fire sizes to bracket the range of possible consequences resulting from large fires involving aboveground tanks/vessels that are part of DBVS.

  6. Fluorescent in situ hybridization for the localization of viruses, bacteria and other microorganisms in insect and plant tissues.

    PubMed

    Kliot, Adi; Ghanim, Murad

    2016-04-01

    Methods for the localization of cellular components such as nucleic acids, proteins, cellular vesicles and more, and the localization of microorganisms including viruses, bacteria and fungi have become an important part of any research program in biological sciences that enable the visualization of these components in fixed and live tissues without the need for complex processing steps. The rapid development of microscopy tools and technologies as well as related fluorescent markers and fluorophores for many cellular components, and the ability to design DNA and RNA sequence-based molecular probes and antibodies which can be visualized fluorescently, have rapidly advanced this field. This review will focus on some of the localizations methods which have been used in plants and insect pests in agriculture, and other microorganisms, which are rapidly advancing the research in agriculture-related fields. PMID:26678796

  7. Extraction and analysis of fumonisins and compounds indicative of fumonisin exposure in plant and mammalian tissues and cultured cells.

    PubMed

    Zitomer, Nicholas C; Riley, Ronald T

    2011-01-01

    Fumonisin mycotoxins are common contaminants in many grains, often at very low levels. Maize is -particularly problematic as one of the organisms that commonly produce fumonisins, the fungus Fusarium verticillioides, often exists as an endophyte of maize. Fumonisin is a potent inhibitor of the enzyme ceramide synthase, and this inhibition results in the accumulation of a variety of upstream compounds, most notably, the sphingoid bases sphingosine, sphinganine, 1-deoxysphinganine and, in plants, phytosphingosine. Fumonisin exposure results in a wide variety of species, sex, and strain-specific responses. This method provides a relatively fast means of extracting fumonisins, sphingoid bases, and sphingoid base 1-phosphates from tissues and cells, as well as the subsequent analyses and quantification of these compounds using liquid chromatography/tandem mass spectrometry. PMID:21567327

  8. Somatic embryogenesis and plant regeneration in Carica papaya L. tissue culture derived from root explants.

    PubMed

    Chen, M H; Wang, P J; Maeda, E

    1987-10-01

    The regeneration potential of shoot tip, stem, leaf, cotyledon and root explants of two papaya cultivars (Carica papaya cv. 'Solo' and cv. 'Sunrise') were studed. Callus induction of these two cultivars of papaya showed that the shoot tips and stems are most suitable for forming callus, while leaves, cotyledons and roots are comparatively difficult to induce callus. Callus induction also varied with the varities. Somatic embryogenesis was obtained from 3-month-old root cultures. A medium containing half strength of MS inorganic salts, 160 mg/l adenine sulfate, 1.0 mg/1 NAA, 0.5 mg/1 kinetin and 1.0 mg/1 GA3 was optimal for embryogenesis. The callus maintained high regenerative capacity after two years of culture on this medium. Plants derived from somatic embryos were obtained under green-house conditions. PMID:24248842

  9. Distribution of Aboveground Live Biomass in the Amazon Basin

    NASA Technical Reports Server (NTRS)

    Saatchi, S. S.; Houghton, R. A.; DosSantos Alvala, R. C.; Soares, J. V.; Yu, Y.

    2007-01-01

    The amount and spatial distribution of forest biomass in the Amazon basin is a major source of uncertainty in estimating the flux of carbon released from land-cover and land-use change. Direct measurements of aboveground live biomass (AGLB) are limited to small areas of forest inventory plots and site-specific allometric equations that cannot be readily generalized for the entire basin. Furthermore, there is no spaceborne remote sensing instrument that can measure tropical forest biomass directly. To determine the spatial distribution of forest biomass of the Amazon basin, we report a method based on remote sensing metrics representing various forest structural parameters and environmental variables, and more than 500 plot measurements of forest biomass distributed over the basin. A decision tree approach was used to develop the spatial distribution of AGLB for seven distinct biomass classes of lowland old-growth forests with more than 80% accuracy. AGLB for other vegetation types, such as the woody and herbaceous savanna and secondary forests, was directly estimated with a regression based on satellite data. Results show that AGLB is highest in Central Amazonia and in regions to the east and north, including the Guyanas. Biomass is generally above 300Mgha(sup 1) here except in areas of intense logging or open floodplains. In Western Amazonia, from the lowlands of Peru, Ecuador, and Colombia to the Andean mountains, biomass ranges from 150 to 300Mgha(sup 1). Most transitional and seasonal forests at the southern and northwestern edges of the basin have biomass ranging from 100 to 200Mgha(sup 1). The AGLB distribution has a significant correlation with the length of the dry season. We estimate that the total carbon in forest biomass of the Amazon basin, including the dead and below ground biomass, is 86 PgC with +/- 20% uncertainty.

  10. Stratified aboveground forest biomass estimation by remote sensing data

    NASA Astrophysics Data System (ADS)

    Latifi, Hooman; Fassnacht, Fabian E.; Hartig, Florian; Berger, Christian; Hernández, Jaime; Corvalán, Patricio; Koch, Barbara

    2015-06-01

    Remote sensing-assisted estimates of aboveground forest biomass are essential for modeling carbon budgets. It has been suggested that estimates can be improved by building species- or strata-specific biomass models. However, few studies have attempted a systematic analysis of the benefits of such stratification, especially in combination with other factors such as sensor type, statistical prediction method and sampling design of the reference inventory data. We addressed this topic by analyzing the impact of stratifying forest data into three classes (broadleaved, coniferous and mixed forest). We compare predictive accuracy (a) between the strata (b) to a case without stratification for a set of pre-selected predictors from airborne LiDAR and hyperspectral data obtained in a managed mixed forest site in southwestern Germany. We used 5 commonly applied algorithms for biomass predictions on bootstrapped subsamples of the data to obtain cross validated RMSE and r2 diagnostics. Those values were analyzed in a factorial design by an analysis of variance (ANOVA) to rank the relative importance of each factor. Selected models were used for wall-to-wall mapping of biomass estimates and their associated uncertainty. The results revealed marginal advantages for the strata-specific prediction models over the unstratified ones, which were more obvious on the wall-to-wall mapped area-based predictions. Yet further tests are necessary to establish the generality of these results. Input data type and statistical prediction method are concluded to remain the two most crucial factors for the quality of remote sensing-assisted biomass models.

  11. Endophytic bacteria in plant tissue culture: differences between easy- and difficult-to-propagate Prunus avium genotypes.

    PubMed

    Quambusch, Mona; Pirttilä, Anna Maria; Tejesvi, Mysore V; Winkelmann, Traud; Bartsch, Melanie

    2014-05-01

    The endophytic bacterial communities of six Prunus avium L. genotypes differing in their growth patterns during in vitro propagation were identified by culture-dependent and culture-independent methods. Five morphologically distinct isolates from tissue culture material were identified by 16S rDNA sequence analysis. To detect and analyze the uncultivable fraction of endophytic bacteria, a clone library was established from the amplified 16S rDNA of total plant extract. Bacterial diversity within the clone libraries was analyzed by amplified ribosomal rDNA restriction analysis and by sequencing a clone for each identified operational taxonomic unit. The most abundant bacterial group was Mycobacterium sp., which was identified in the clone libraries of all analyzed Prunus genotypes. Other dominant bacterial genera identified in the easy-to-propagate genotypes were Rhodopseudomonas sp. and Microbacterium sp. Thus, the community structures in the easy- and difficult-to-propagate cherry genotypes differed significantly. The bacterial genera, which were previously reported to have plant growth-promoting effects, were detected only in genotypes with high propagation success, indicating a possible positive impact of these bacteria on in vitro propagation of P. avium, which was proven in an inoculation experiment. PMID:24812040

  12. Cell surface and cell outline imaging in plant tissues using the backscattered electron detector in a variable pressure scanning electron microscope

    PubMed Central

    2013-01-01

    Background Scanning electron microscopy (SEM) has been used for high-resolution imaging of plant cell surfaces for many decades. Most SEM imaging employs the secondary electron detector under high vacuum to provide pseudo-3D images of plant organs and especially of surface structures such as trichomes and stomatal guard cells; these samples generally have to be metal-coated to avoid charging artefacts. Variable pressure-SEM allows examination of uncoated tissues, and provides a flexible range of options for imaging, either with a secondary electron detector or backscattered electron detector. In one application, we used the backscattered electron detector under low vacuum conditions to collect images of uncoated barley leaf tissue followed by simple quantification of cell areas. Results Here, we outline methods for backscattered electron imaging of a variety of plant tissues with particular focus on collecting images for quantification of cell size and shape. We demonstrate the advantages of this technique over other methods to obtain high contrast cell outlines, and define a set of parameters for imaging Arabidopsis thaliana leaf epidermal cells together with a simple image analysis protocol. We also show how to vary parameters such as accelerating voltage and chamber pressure to optimise imaging in a range of other plant tissues. Conclusions Backscattered electron imaging of uncoated plant tissue allows acquisition of images showing details of plant morphology together with images of high contrast cell outlines suitable for semi-automated image analysis. The method is easily adaptable to many types of tissue and suitable for any laboratory with standard SEM preparation equipment and a variable-pressure-SEM or tabletop SEM. PMID:24135233

  13. Glutamine nitrogen and ammonium nitrogen supplied as a nitrogen source is not converted into nitrate nitrogen of plant tissues of hydroponically grown pak-choi (Brassica chinensis L.).

    PubMed

    Wang, H-J; Wu, L-H; Tao, Q-N; Miller, D D; Welch, R M

    2009-03-01

    Many vegetables, especially leafy vegetables, accumulate NO(-) (3)-N in their edible portions. High nitrate levels in vegetables constitute a health hazard, such as cancers and blue baby syndrome. The aim of this study was to determine if (1) ammonium nitrogen (NH(+) (4)-N) and glutamine-nitrogen (Gln-N) absorbed by plant roots is converted into nitrate-nitrogen of pak-choi (Brassica chinensis L.) tissues, and (2) if nitrate-nitrogen (NO(-) (3)-N) accumulation and concentration of pak-choi tissues linearly increase with increasing NO(-) (3)-N supply when grown in nutrient solution. In experiment 1, 4 different nitrogen treatments (no nitrogen, NH(+) (4)-N, Gln-N, and NO(-) (3)-N) with equal total N concentrations in treatments with added N were applied under sterile nutrient medium culture conditions. In experiment 2, 5 concentrations of N (from 0 to 48 mM), supplied as NO(-) (3)-N in the nutrient solution, were tested. The results showed that Gln-N and NH(+) (4)-N added to the nutrient media were not converted into nitrate-nitrogen of plant tissues. Also, NO(-) (3)-N accumulation in the pak-choi tissues was the highest when plants were supplied 24 mM NO(-) (3)-N in the media. The NO(-) (3)-N concentration in plant tissues was quadratically correlated to the NO(-) (3)-N concentration supplied in the nutrient solution. PMID:19323774

  14. Monitoring plant tissue nitrogen isotopes to assess nearshore inputs of nitrogen to Lake Crescent, Olympic National Park, Washington

    USGS Publications Warehouse

    Cox, Stephen E.; Moran, Patrick W.; Huffman, Raegan L.; Fradkin, Steven C.

    2016-01-01

    Mats of filamentous-periphytic algae present in some nearshore areas of Lake Crescent, Olympic National Park, Washington, may indicate early stages of eutrophication from nutrient enrichment of an otherwise highly oligotrophic lake. Natural abundance ratios of stable isotopes of nitrogen (δ15N) measured in plant tissue growing in nearshore areas of the lake indicate that the major source of nitrogen used by these primary producing plants is derived mainly from atmospherically fixed nitrogen in an undeveloped forested ecosystem. Exceptions to this pattern occurred in the Barnes Point area where elevated δ15N ratios indicate that effluent from septic systems also contribute nitrogen to filamentous-periphytic algae growing in the littoral zone of that area. Near the Lyre River outlet of Lake Crescent, the δ15N of filamentous-periphytic algae growing in close proximity to the spawning areas of a unique species of trout show little evidence of elevated δ15N indicating that nitrogen from on-site septic systems is not a substantial source of nitrogen for these plants. The δ15N data corroborate estimates that nitrogen input to Lake Crescent from septic sources is comparatively small relative to input from motor vehicle exhaust and vegetative sources in undeveloped forests, including litterfall, pollen, and symbiotic nitrogen fixation. The seasonal timing of blooms of filamentous-periphytic algal near the lake shoreline is also consistent with nitrogen exported from stands of red alder trees (Alnus rubra). Isotope biomonitoring of filamentous-periphytic algae may be an effective approach to monitoring the littoral zone for nutrient input to Lake Crescent from septic sources.

  15. A novel method for prenylquinone profiling in plant tissues by ultra-high pressure liquid chromatography-mass spectrometry

    PubMed Central

    2011-01-01

    Background Prenylquinones are key compounds of the thylakoid membranes in chloroplasts. To understand the mechanisms involved in the response of plants to changing conditions such as high light intensity, the comprehensive analysis of these apolar lipids is an essential but challenging step. Conventional methods are based on liquid chromatography coupled to ultraviolet and fluorescence detection of a single or limited number of prenylquinones at a time. Here we present an original and rapid approach using ultra-high pressure liquid chromatography-atmospheric pressure chemical ionization-quadrupole time-of-flight mass spectrometry (UHPLC-APCI-QTOFMS) for the simultaneous profiling of eleven prenylquinones in plant tissues, including α-tocopherol, phylloquinone, plastochromanol-8 and plastoquinone-9. Results and discussion Mass spectrometry and chromatography parameters were optimized using pure standards. Sample preparation time was kept to minimum and different extraction solvents were evaluated for yield, ability to maintain the redox state of prenylquinones, and compatibility with chromatography. In addition to precise absolute quantification of 5 prenyllipids for which standards were available, relative quantification of 6 other related compounds was possible thanks to the high identification power of QTOFMS. Prenylquinone levels were measured in leaves of Arabidopsis grown under normal and high light intensities. Quantitatively, the obtained results were consistent with those reported in various previous studies, demonstrating that this new method can profile the full range of prenylquinones in a very short time. Conclusion The new profiling method proves faster, more sensitive and can detect more prenylquinones than current methods based on measurements of selected compounds. It enables the extraction and analysis of twelve samples in only 1.5 h and may be applied to other plant species or cultivars. PMID:21777468

  16. Influence of simulated acid snow stress on leaf tissue of wintering herbaceous plants.

    PubMed

    Inada, Hidetoshi; Nagao, Manabu; Fujikawa, Seizo; Arakawa, Keita

    2006-04-01

    Acid snow might be an environmental stress factor for wintering plants since acid precipitates are locally concentrated in snow and the period in which ice crystals are in contact with shoots might be longer than that of acid precipitates in rain. In this study, 'equilibrium' and 'prolonged' freezing tests with sulfuric acid, which simulate situations of temperature depression and chronic freezing at a subzero temperature with acid precipitate as acid snow stress, respectively, were carried out using leaf segments of cold-acclimated winter wheat. When leaf segments were frozen in the presence of sulfuric acid solution (pH 4.0, 3.0 or 2.0) by equilibrium freezing with ice seeding, the survival rate of leaf samples treated with sulfuric acid solution of pH 2.0 decreased markedly. Leaf samples after supercooling to -4 and -8 degrees C in the presence of sulfuric acid solution (pH 2.0) without ice seeding were less damaged. When leaf samples were subjected to prolonged freezing at -4 and -8 degrees C for 7 d with sulfuric acid (pH 2.0), the survival rates of leaf samples exposed to sulfuric acid decreased more than those of leaf samples treated with water. On the other hand, leaf samples were less damaged by prolonged supercooling at -4 and -8 degrees C for 7 d with sulfuric acid (pH 2.0). The results suggest that an acid condition (pH 2.0) in the process of extracellular freezing and/or thawing promotes freezing injury of wheat leaves. PMID:16481360

  17. Aboveground and belowground legacies of native Sami land use on boreal forest in northern Sweden 100 years after abandonment.

    PubMed

    Freschet, Grégoire T; Ostlund, Lars; Kichenin, Emilie; Wardle, David A

    2014-04-01

    Human activities that involve land-use change often cause major transformations to community and ecosystem properties both aboveground and belowground, and when land use is abandoned, these modifications can persist for extended periods. However, the mechanisms responsible for rapid recovery vs. long-term maintenance of ecosystem changes following abandonment remain poorly understood. Here, we examined the long-term ecological effects of two remote former settlements, regularly visited for -300 years by reindeer-herding Sami and abandoned -100 years ago, within an old-growth boreal forest that is considered one of the most pristine regions in northern Scandinavia. These human legacies were assessed through measurements of abiotic and biotic soil properties and vegetation characteristics at the settlement sites and at varying distances from them. Low-intensity land use by Sami is characterized by the transfer of organic matter towards the settlements by humans and reindeer herds, compaction of soil through trampling, disappearance of understory vegetation, and selective cutting of pine trees for fuel and construction. As a consequence, we found a shift towards early successional plant species and a threefold increase in soil microbial activity and nutrient availability close to the settlements relative to away from them. These changes in soil fertility and vegetation contributed to 83% greater total vegetation productivity, 35% greater plant biomass, and 23% and 16% greater concentrations of foliar N and P nearer the settlements, leading to a greater quantity and quality of litter inputs. Because decomposer activity was also 40% greater towards the settlements, soil organic matter cycling and nutrient availability were further increased, leading to likely positive feedbacks between the aboveground and belowground components resulting from historic land use. Although not all of the activities typical of Sami have left visible residual traces on the ecosystem after

  18. Survivorship and plant-plant interactions: Maintaining the evolutionary potential of restored populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ecological models of plant competition predict both low growth rate variance when below-ground competition occurs and high growth rate variance in above-ground competition. Reproductive output in annual plants is highly correlated with plant size, therefore models of plant competition also predict ...

  19. Aboveground vs. Belowground Carbon Stocks in African Tropical Lowland Rainforest: Drivers and Implications

    PubMed Central

    Bauters, Marijn; Hufkens, Koen; Lisingo, Janvier; Baert, Geert; Verbeeck, Hans; Boeckx, Pascal

    2015-01-01

    Background African tropical rainforests are one of the most important hotspots to look for changes in the upcoming decades when it comes to C storage and release. The focus of studying C dynamics in these systems lies traditionally on living aboveground biomass. Belowground soil organic carbon stocks have received little attention and estimates of the size, controls and distribution of soil organic carbon stocks are highly uncertain. In our study on lowland rainforest in the central Congo basin, we combine both an assessment of the aboveground C stock with an assessment of the belowground C stock and analyze the latter in terms of functional pools and controlling factors. Principal Findings Our study shows that despite similar vegetation, soil and climatic conditions, soil organic carbon stocks in an area with greater tree height (= larger aboveground carbon stock) were only half compared to an area with lower tree height (= smaller aboveground carbon stock). This suggests that substantial variability in the aboveground vs. belowground C allocation strategy and/or C turnover in two similar tropical forest systems can lead to significant differences in total soil organic C content and C fractions with important consequences for the assessment of the total C stock of the system. Conclusions/Significance We suggest nutrient limitation, especially potassium, as the driver for aboveground versus belowground C allocation. However, other drivers such as C turnover, tree functional traits or demographic considerations cannot be excluded. We argue that large and unaccounted variability in C stocks is to be expected in African tropical rain-forests. Currently, these differences in aboveground and belowground C stocks are not adequately verified and implemented mechanistically into Earth System Models. This will, hence, introduce additional uncertainty to models and predictions of the response of C storage of the Congo basin forest to climate change and its contribution to

  20. Functional soil microbiome: belowground solutions to an aboveground problem.

    PubMed

    Lakshmanan, Venkatachalam; Selvaraj, Gopinath; Bais, Harsh P

    2014-10-01

    There is considerable evidence in the literature that beneficial rhizospheric microbes can alter plant morphology, enhance plant growth, and increase mineral content. Of late, there is a surge to understand the impact of the microbiome on plant health. Recent research shows the utilization of novel sequencing techniques to identify the microbiome in model systems such as Arabidopsis (Arabidopsis thaliana) and maize (Zea mays). However, it is not known how the community of microbes identified may play a role to improve plant health and fitness. There are very few detailed studies with isolated beneficial microbes showing the importance of the functional microbiome in plant fitness and disease protection. Some recent work on the cultivated microbiome in rice (Oryza sativa) shows that a wide diversity of bacterial species is associated with the roots of field-grown rice plants. However, the biological significance and potential effects of the microbiome on the host plants are completely unknown. Work performed with isolated strains showed various genetic pathways that are involved in the recognition of host-specific factors that play roles in beneficial host-microbe interactions. The composition of the microbiome in plants is dynamic and controlled by multiple factors. In the case of the rhizosphere, temperature, pH, and the presence of chemical signals from bacteria, plants, and nematodes all shape the environment and influence which organisms will flourish. This provides a basis for plants and their microbiomes to selectively associate with one another. This Update addresses the importance of the functional microbiome to identify phenotypes that may provide a sustainable and effective strategy to increase crop yield and food security. PMID:25059708

  1. Soil nutrients affect spatial patterns of aboveground biomass and emergent tree density in southwestern Borneo.

    PubMed

    Paoli, Gary D; Curran, Lisa M; Slik, J W F

    2008-03-01

    Studies on the relationship between soil fertility and aboveground biomass in lowland tropical forests have yielded conflicting results, reporting positive, negative and no effect of soil nutrients on aboveground biomass. Here, we quantify the impact of soil variation on the stand structure of mature Bornean forest throughout a lowland watershed (8-196 m a.s.l.) with uniform climate and heterogeneous soils. Categorical and bivariate methods were used to quantify the effects of (1) parent material differing in nutrient content (alluvium > sedimentary > granite) and (2) 27 soil parameters on tree density, size distribution, basal area and aboveground biomass. Trees > or =10 cm (diameter at breast height, dbh) were enumerated in 30 (0.16 ha) plots (sample area = 4.8 ha). Six soil samples (0-20 cm) per plot were analyzed for physiochemical properties. Aboveground biomass was estimated using allometric equations. Across all plots, stem density averaged 521 +/- 13 stems ha(-1), basal area 39.6 +/- 1.4 m(2) ha(-1) and aboveground biomass 518 +/- 28 Mg ha(-1) (mean +/- SE). Adjusted forest-wide aboveground biomass to account for apparent overestimation of large tree density (based on 69 0.3-ha transects; sample area = 20.7 ha) was 430 +/- 25 Mg ha(-1). Stand structure did not vary significantly among substrates, but it did show a clear trend toward larger stature on nutrient-rich alluvium, with a higher density and larger maximum size of emergent trees. Across all plots, surface soil phosphorus (P), potassium, magnesium and percentage sand content were significantly related to stem density and/or aboveground biomass (R (Pearson) = 0.368-0.416). In multiple linear regression, extractable P and percentage sand combined explained 31% of the aboveground biomass variance. Regression analyses on size classes showed that the abundance of emergent trees >120 cm dbh was positively related to soil P and exchangeable bases, whereas trees 60-90 cm dbh were negatively related to these

  2. A sensitive PCR-based assay to detect Neotyphodium fungi in seed and plant tissue of tall fescue and ryegrass spp.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A polymerase chain reaction (PCR)-based method for detection of Neotyphodium endophytes in seed and plant tissue from tall fescue (Festuca arundinacea Schreb.), Italian (Lolium multiflorum Lam.) and perennial (Lolium perenne L.) ryegrasses was developed. Based on DNA mixture tests and bulk seed anal...

  3. Tissue-Specific, Development-Dependent Phenolic Compounds Accumulation Profile and Gene Expression Pattern in Tea Plant [Camellia sinensis

    PubMed Central

    Li, Weiwei; Zhao, Lei; Meng, Fei; Wang, Yunsheng; Tan, Huarong; Yang, Hua; Wei, Chaoling; Wan, Xiaochun; Gao, Liping; Xia, Tao

    2013-01-01

    Phenolic compounds in tea plant [Camellia sinensis (L.)] play a crucial role in dominating tea flavor and possess a number of key pharmacological benefits on human health. The present research aimed to study the profile of tissue-specific, development-dependent accumulation pattern of phenolic compounds in tea plant. A total of 50 phenolic compounds were identified qualitatively using liquid chromatography in tandem mass spectrometry technology. Of which 29 phenolic compounds were quantified based on their fragmentation behaviors. Most of the phenolic compounds were higher in the younger leaves than that in the stem and root, whereas the total amount of proanthocyanidins were unexpectedly higher in the root. The expression patterns of 63 structural and regulator genes involved in the shikimic acid, phenylpropanoid, and flavonoid pathways were analyzed by quantitative real-time polymerase chain reaction and cluster analysis. Based on the similarity of their expression patterns, the genes were classified into two main groups: C1 and C2; and the genes in group C1 had high relative expression level in the root or low in the bud and leaves. The expression patterns of genes in C2-2-1 and C2-2-2-1 groups were probably responsible for the development-dependent accumulation of phenolic compounds in the leaves. Enzymatic analysis suggested that the accumulation of catechins was influenced simultaneously by catabolism and anabolism. Further research is recommended to know the expression patterns of various genes and the reason for the variation in contents of different compounds in different growth stages and also in different organs. PMID:23646127

  4. Tissue-specific, development-dependent phenolic compounds accumulation profile and gene expression pattern in tea plant [Camellia sinensis].

    PubMed

    Jiang, Xiaolan; Liu, Yajun; Li, Weiwei; Zhao, Lei; Meng, Fei; Wang, Yunsheng; Tan, Huarong; Yang, Hua; Wei, Chaoling; Wan, Xiaochun; Gao, Liping; Xia, Tao

    2013-01-01

    Phenolic compounds in tea plant [Camellia sinensis (L.)] play a crucial role in dominating tea flavor and possess a number of key pharmacological benefits on human health. The present research aimed to study the profile of tissue-specific, development-dependent accumulation pattern of phenolic compounds in tea plant. A total of 50 phenolic compounds were identified qualitatively using liquid chromatography in tandem mass spectrometry technology. Of which 29 phenolic compounds were quantified based on their fragmentation behaviors. Most of the phenolic compounds were higher in the younger leaves than that in the stem and root, whereas the total amount of proanthocyanidins were unexpectedly higher in the root. The expression patterns of 63 structural and regulator genes involved in the shikimic acid, phenylpropanoid, and flavonoid pathways were analyzed by quantitative real-time polymerase chain reaction and cluster analysis. Based on the similarity of their expression patterns, the genes were classified into two main groups: C1 and C2; and the genes in group C1 had high relative expression level in the root or low in the bud and leaves. The expression patterns of genes in C2-2-1 and C2-2-2-1 groups were probably responsible for the development-dependent accumulation of phenolic compounds in the leaves. Enzymatic analysis suggested that the accumulation of catechins was influenced simultaneously by catabolism and anabolism. Further research is recommended to know the expression patterns of various genes and the reason for the variation in contents of different compounds in different growth stages and also in different organs. PMID:23646127

  5. Estimating forest and woodland aboveground biomass using active and passive remote sensing

    USGS Publications Warehouse

    Wu, Zhuoting; Dye, Dennis G.; Vogel, John M.; Middleton, Barry R.

    2016-01-01

    Aboveground biomass was estimated from active and passive remote sensing sources, including airborne lidar and Landsat-8 satellites, in an eastern Arizona (USA) study area comprised of forest and woodland ecosystems. Compared to field measurements, airborne lidar enabled direct estimation of individual tree height with a slope of 0.98 (R2 = 0.98). At the plot-level, lidar-derived height and intensity metrics provided the most robust estimate for aboveground biomass, producing dominant species-based aboveground models with errors ranging from 4 to 14Mg ha –1 across all woodland and forest species. Landsat-8 imagery produced dominant species-based aboveground biomass models with errors ranging from 10 to 28 Mg ha –1. Thus, airborne lidar allowed for estimates for fine-scale aboveground biomass mapping with low uncertainty, while Landsat-8 seems best suited for broader spatial scale products such as a national biomass essential climate variable (ECV) based on land cover types for the United States.

  6. Quantification of uncertainty in aboveground biomass estimates derived from small-footprint LiDAR data

    NASA Astrophysics Data System (ADS)

    Xu, Q.; Greenberg, J. A.; Li, B.; Ramirez, C.; Balamuta, J. J.; Evans, K.; Man, A.; Xu, Z.

    2015-12-01

    A promising approach to determining aboveground biomass (AGB) in forests comes through the use of individual tree crown delineation (ITCD) techniques applied to small-footprint LiDAR data. These techniques, when combined with allometric equations, can produce per-tree estimates of AGB. At this scale, AGB estimates can be quantified in a manner similar to how ground-based forest inventories are produced. However, these approaches have significant uncertainties that are rarely described in full. Allometric equations are often based on species-specific diameter-at-breast height (DBH) relationships, but neither DBH nor species can be reliably determined using remote sensing analysis. Furthermore, many approaches to ITCD only delineate trees appearing in the upper canopy so subcanopy trees are often missing from the inventories. In this research, we performed a propagation-of-error analysis to determine the spatially varying uncertainties in AGB estimates at the individual plant and stand level for a large collection of LiDAR acquisitions covering a large portion of California. Furthermore, we determined the relative contribution of various aspects of the analysis towards the uncertainty, including errors in the ITCD results, the allometric equations, the taxonomic designation, and the local biophysical environment. Watershed segmentation was used to obtain the preliminary crown segments. Lidar points within the preliminary segments were extracted to form profiling data of the segments, and then mode detection algorithms were applied to identify the tree number and tree heights within each segment. As part of this analysis, we derived novel "remote sensing aware" allometric equations and their uncertainties based on three-dimensional morphological metrics that can be accurately derived from LiDAR data.

  7. Cultural characteristics of Sporisorium sorghi and detection of the pathogen in plant tissue by microscopy and PCR.

    PubMed

    Moharam, M H A; Leclerque, A; Koch, E

    2012-01-01

    Despite the economic importance of covered kernel smut of sorghum (Sporisorium sorghi) in many African states and other parts of the world, only limited information is available on laboratory cultivation methods for this fungus and techniques for its diagnosis in plant tissue. When in the present study spores of S. sorghi were kept as intact sori at 5 degrees C, 80% of the spores germinated even after 24 months of storage. Spore germination on agar medium and production of mycelial dry weight in still culture were highest between 20 and 35 degrees C, with a peak at 30 degrees C. Both showed a steady increase from pH 4.5 to pH 7.5, followed by a decline at pH 8.5 and 9.5. In shake culture in different broth media the addition of 0.3% peptone from soybean caused an increase in fungal growth compared to the media alone. Of the media tested, mycelial production was highest in malt dextrose broth supplemented with peptone. When cultivated on different agar media, the morphology of single spore isolates differed both among isolates and depending on the agar medium. In greenhouse experiments, five short heighted, early maturing sorghum breeding accessions proved to be partially or fully resistant to covered kernel smut. Among the plant material tested, cv. 'Dorado' appeared to be the one best suited for greenhouse experiments with covered kernel smut. By microscopy of hand-cut sections stained with trypan-blue, hyphae of S. sorghi were seen in apical buds and in nodes of young sorghum plants. Diagnostic PCR amplified a 903 bp element comprising the internal region of the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) encoding gene and enabled the detection of S. sorghi in both nodes and apical buds of infected sorghum seedlings. Both techniques, i.e. microscopy and diagnostic PCR have the potential to be used in studies for the identification of effective sorghum seed treatments already at the seedling stage. PMID:23878987

  8. Efficient extraction of proteins from recalcitrant plant tissue for subsequent analysis by two-dimensional gel electrophoresis.

    PubMed

    Parkhey, Suruchi; Chandrakar, Vibhuti; Naithani, S C; Keshavkant, S

    2015-10-01

    Protein extraction for two-dimensional electrophoresis from tissues of recalcitrant species is quite problematic and challenging due to the low protein content and high abundance of contaminants. Proteomics in Shorea robusta is scarcely conducted due to the lack of a suitable protein preparation procedure. To establish an effective protein extraction protocol suitable for two-dimensional electrophoresis in Shorea robusta, four procedures (borate buffer/trichloroacetic acid extraction, organic solvent/trichloroacetic acid precipitation, sucrose/Tris/phenol, and organic solvent/phenol/sodium dodecyl sulfate) were evaluated. Following these, proteins were isolated from mature leaves and were analyzed for proteomics, and also for potential contaminants, widely reported to hinder proteomics. The borate buffer/trichloroacetic acid extraction had the lowest protein yield and did not result in any banding even in one-dimensional electrophoresis. In contrast, organic solvent/phenol/sodium dodecyl sulfate extraction allowed the highest protein yield. Moreover, during proteomics, organic solvent/phenol/sodium dodecyl sulfate extracted protein resolved the maximum number (144) of spots. Further, when proteins were evaluated for contaminants, significant (77-95%) reductions in the nucleic acids, phenol, and sugars were discernible with refinement in extraction procedure. Accumulated data suggested that the organic solvent/phenol/sodium dodecyl sulfate extraction was the most effective protocol for protein isolation for proteomics of Shorea robusta and can be used for plants that have a similar set of contaminants. PMID:26257211

  9. Stability and extractability of double-stranded RNA of pangola stunt and sugarcane Fiji disease viruses in dried plant tissues.

    PubMed

    Karan, M; Hicks, S; Harding, R M; Teakle, D S

    1991-06-01

    When leaves infected with pangola stunt virus (PaSV) were dried at 23, 37, 50, 70 or 105 degrees C, the dsRNA was stable and could be extracted after aerobic storage at room temperature for 1 month, although at 105 degrees C the amount obtained was reduced. The dsRNA was also recovered after leaves were freeze dried and stored in vacuo at room temperature for 6 months, or were dried and stored aerobically at room temperature for 10.5 months. dsRNA of sugarcane Fiji disease virus (FDV) was also stable when infected leaves were dried at 23, 37, 50 or 105 degrees C and stored aerobically for 3 months or for at least 6 months when infected leaves were dried at 70 degrees C. The unexpected high stability and extractability of both PaSV and FDV dsRNA when dried in leaves at low or high temperatures and stored at room temperature indicate that these, and probably other plant-infecting reoviruses, can be transported readily in desiccated host tissue between different countries for later extraction and comparison of their dsRNAs. PMID:1939508

  10. Diverse roles of ERECTA family genes in plant development.

    PubMed

    Shpak, Elena D

    2013-12-01

    Multiple receptor-like kinases (RLKs) enable intercellular communication that coordinates growth and development of plant tissues. ERECTA family receptors (ERfs) are an ancient family of leucine-rich repeat RLKs that in Arabidopsis consists of three genes: ERECTA, ERL1, and ERL2. ERfs sense secreted cysteine-rich peptides from the EPF/EPFL family and transmit the signal through a MAP kinase cascade. This review discusses the functions of ERfs in stomata development, in regulation of longitudinal growth of aboveground organs, during reproductive development, and in the shoot apical meristem. In addition the role of ERECTA in plant responses to biotic and abiotic factors is examined. Elena D. Shpak (Corresponding author). PMID:24016315

  11. Influence of atmospheric [CO2] on growth, carbon allocation and cost of plant tissues on leaf nitrogen concentration maintenance in nodulated Medicago sativa

    NASA Astrophysics Data System (ADS)

    Pereyra, Gabriela; Hartmann, Henrik; Ziegler, Waldemar; Michalzik, Beate; Gonzalez-Meler, Miquel; Trumbore, Susan

    2015-04-01

    Plant carbon (C) allocation and plant metabolic processes (i.e. photosynthesis and respiration) can be affected by changes in C availability, for example from changing atmospheric [CO2]. In nodulated plants, C availability may also influence nitrogen (N) fixation by bacteriods. But C allocation and N fixation are often studied independently and hence do not allow elucidating interactive effects. We investigated how different atmospheric [CO2] (Pleistocene: 170 ppm, ambient: 400 ppm and projected future: 700 ppm) influence plant growth, allocation to nodules, and the ratio of photosynthesis-to-respiration (R:A) as an indicator of C cost in Medicago sativa inoculated with Ensifer meliloti. M. sativa grew c. 38% more nodules at 400 ppm and 700 ppm than at 170 ppm. However, ratios of above- and belowground plant biomass to nodule biomass were constant over time and independent of atmospheric [CO2]. Total non-structural carbohydrate concentrations were not significantly different between plants grown at 400 and 700 ppm, but were four to five-fold higher than in 170 ppm plants. Leaf level N concentration was similar across treatments, but N-based photosynthetic rates were 82% and 93% higher in leaves of plants grown at 400 and 700 ppm, respectively, than plants grown at 170 ppm. In addition, leaf R:A was greater (48% or 55%) in plants grown at 170 ppm than plants grown at 400 and 700 ppm. Similarly, the greatest proportion of assimilated CO2 released by root respiration occurred in rhizobial plants growing at 170 ppm. Our results suggest that C limitation in nodulated Medicago sativa plants did not influence C allocation to nodule biomass but caused a proportionally greater allocation of C to belowground respiration, most likely to bacteriods. This suggests that N tissue concentration was maintained at low [CO2] by revving up bacteriod metabolism and at the expense of non-structural carbohydrate reserves.

  12. Aboveground predation by an American badger (Taxidea taxus) on black-tailed prairie dogs (Cynomys ludovicianus)

    USGS Publications Warehouse

    Eads, D.A.; Biggins, D.E.

    2008-01-01

    During research on black-tailed prairie dogs (Cynomys ludovicianus), we repeatedly observed a female American badger (Taxidea taxus) hunting prairie dogs on a colony in southern Phillips County, Montana. During 1-14 June 2006, we observed 7 aboveground attacks (2 successful) and 3 successful excavations of prairie dogs. The locations and circumstances of aboveground attacks suggested that the badger improved her probability of capturing prairie dogs by planning the aboveground attacks based on perceptions of speeds, angles, distances, and predicted escape responses of prey. Our observations add to previous reports on the complex and varied predatory methods and cognitive capacities of badgers. These observations also underscore the individuality of predators and support the concept that predators are active participants in predator-prey interactions.

  13. Aboveground and Belowground Herbivores Synergistically Induce Volatile Organic Sulfur Compound Emissions from Shoots but Not from Roots.

    PubMed

    Danner, Holger; Brown, Phil; Cator, Eric A; Harren, Frans J M; van Dam, Nicole M; Cristescu, Simona M

    2015-07-01

    Studies on aboveground (AG) plant organs have shown that volatile organic compound (VOC) emissions differ between simultaneous attack by herbivores and single herbivore attack. There is growing evidence that interactive effects of simultaneous herbivory also occur across the root-shoot interface. In our study, Brassica rapa roots were infested with root fly larvae (Delia radicum) and the shoots infested with Pieris brassicae, either singly or simultaneously, to study these root-shoot interactions. As an analytical platform, we used Proton Transfer Reaction Mass Spectrometry (PTR-MS) to investigate VOCs over a 3 day time period. Our set-up allowed us to monitor root and shoot emissions concurrently on the same plant. Focus was placed on the sulfur-containing compounds; methanethiol, dimethylsulfide (DMS), and dimethyldisulfide (DMDS), because these compounds previously have been shown to be biologically active in the interactions of Brassica plants, herbivores, parasitoids, and predators, yet have received relatively little attention. The shoots of plants simultaneously infested with AG and belowground (BG) herbivores emitted higher levels of sulfur-containing compounds than plants with a single herbivore species present. In contrast, the emission of sulfur VOCs from the plant roots increased as a consequence of root herbivory, independent of the presence of an AG herbivore. The onset of root emissions was more rapid after damage than the onset of shoot emissions. The shoots of double infested plants also emitted higher levels of methanol. Thus, interactive effects of root and shoot herbivores exhibit more strongly in the VOC emissions from the shoots than from the roots, implying the involvement of specific signaling interactions. PMID:26195194

  14. The Microbe-Free Plant: Fact or Artifact?

    PubMed Central

    Partida-Martínez, Laila P.; Heil, Martin

    2011-01-01

    Plant–microbe interactions are ubiquitous. Plants are threatened by pathogens, but they are even more commonly engaged in neutral or mutualistic interactions with microbes: belowground microbial plant associates are mycorrhizal fungi, Rhizobia, and plant-growth promoting rhizosphere bacteria, aboveground plant parts are colonized by internally living bacteria and fungi (endophytes) and by microbes in the phyllosphere (epiphytes). We emphasize here that a completely microbe-free plant is an exotic exception rather than the biologically relevant rule. The complex interplay of such microbial communities with the host–plant affects multiple vital parameters such as plant nutrition, growth rate, resistance to biotic and abiotic stressors, and plant survival and distribution. The mechanisms involved reach from direct ones such as nutrient acquisition, the production of plant hormones, or direct antibiosis, to indirect ones that are mediated by effects on host resistance genes or via interactions at higher trophic levels. Plant-associated microbes are heterotrophic and cause costs to their host plant, whereas the benefits depend on the current environment. Thus, the outcome of the interaction for the plant host is highly context dependent. We argue that considering the microbe-free plant as the “normal” or control stage significantly impairs research into important phenomena such as (1) phenotypic and epigenetic plasticity, (2) the “normal” ecological outcome of a given interaction, and (3) the evolution of plants. For the future, we suggest cultivation-independent screening methods using direct PCR from plant tissue of more than one fungal and bacterial gene to collect data on the true microbial diversity in wild plants. The patterns found could be correlated to host species and environmental conditions, in order to formulate testable hypotheses on the biological roles of plant endophytes in nature. Experimental approaches should compare different host

  15. Potential for radionuclide redistribution due to biotic intrusion: Aboveground biomass study at the Los Alamos National Laboratory for the closure of Material Disposal Area G

    SciTech Connect

    Beguin, K.; Pressler, R.E.; Christensen, C.; Anderson, T.; French, S.; Schuman, R.

    2008-07-01

    Low-level radioactive waste generated at the Los Alamos National Laboratories (LANL) is disposed of at Technical Area (TA) 54, Material Disposal Area (MDA) G. The ability of MDA G to safely contain radioactive waste was evaluated in the facility's performance assessment (PA) and composite analysis (CA). The PA and CA project that, due to uptake and incorporation of radionuclides into aboveground plant material, plant roots penetrating into buried waste may lead to releases of radionuclides to the accessible environment and potentially lead to the exposure to members of the public. The potential amount of contamination deposited on the ground surface, due to plant intrusion into buried waste, is a function of the quantity of litter generated by plants, as well as radionuclide concentrations within the litter. Radionuclide concentrations in plant litter is dependent on the distribution of root mass with depth and the efficiency with which radionuclides are extracted from contaminated soils by the plants roots. In order to reduce uncertainties associated with the PA and CA for MDA G, aboveground biomass surveys, plant litter production rates, and root mass with depth analyses for the four prominent vegetation types (grasses, forbs, shrubs and trees) are being conducted. Sampling occurred during the months of August and September of 2007 which measured aboveground biomass for the types of grasses and forbs that may become established at MDA G after the disposal facility undergoes final closure. Biomass data are representative of the future potential for the amount of contaminated plant litter fall, which could act as a latent conduit for radionuclide transport from the closed disposal area. Follow on work will be conducted to evaluate frequency and coverage of all growth forms, litter production rates will be measured, and root mass with depth for grasses, forbs, shrubs, and trees will be analyzed. Together, data collected are expected to reduce uncertainties

  16. Role of different salt marsh plants on metal retention in an urban estuary (Lima estuary, NW Portugal)

    NASA Astrophysics Data System (ADS)

    Almeida, C. M. R.; Mucha, Ana P.; Teresa Vasconcelos, M.

    2011-01-01

    The aim of the present work was to understand the role different salt marsh plants on metal distribution and retention in the Lima River estuary (NW Portugal), which to our knowledge have not been ascertained in this area yet. The knowledge of these differences is an important requirement for the development of appropriate management strategies, and is poorly described for Eurosiberian estuaries, like the one selected. In addition it is important to understand the difference among introduced and native salt marsh plants. In this work, metal levels (Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) were surveyed (by atomic absorption spectrometry) in sediments from sites vegetated with Juncus maritimus, Spartina patens, Phragmites australis and Triglochin striata (rhizo-sediments), in non-vegetated sediments and in the different tissues of the plants (roots, rhizomes and aerial shoots). In general, rhizo-sediments had higher metal concentrations than non-vegetated sediments, a feature that seems common to sediments colonized by salt marsh plants of different estuarine areas. All plants concentrated metals, at least Cd, Cu and Zn (and Pb for T. striata) in their belowground structures ([ M] belowground tissues/[ M] non-vegetated sediment > 1). However, when considered per unit of salt marsh area, the different selected plants played a different role on sediment metal distribution and retention. Triglochin striata retained a significant metal burden in it belowground structures (root plus rhizomes) acting like a possible phyto-stabilizer, whereas P. australis had an higher metal burden in aboveground tissues acting as a possible phyto-extractor. As for J. maritimus and S. patens, metal burden distribution between above and belowground structures depended on the metal, with J. maritimus retaining, for instance, much more Cd and Cu in the aboveground than in the belowground structures. Therefore, the presence of invasive and exotic plants in some areas of the salt marsh may

  17. Range vegetation type mapping and above-ground green biomass estimations using multispectral imagery. [Wyoming

    NASA Technical Reports Server (NTRS)

    Houston, R. S. (Principal Investigator); Gordon, R. C.

    1974-01-01

    The author has identified the following significant results. Range vegetation types have been successfully mapped on a portion of the 68,000 acre study site located west of Baggs, Wyoming, using ERTS-1 imagery. These types have been ascertained from field transects over a five year period. Comparable studies will be made with EREP imagery. Above-ground biomass estimation studies are being conducted utilizing double sampling techniques on two similar study sites. Information obtained will be correlated with percent relative reflectance measurements obtained on the ground which will be related to image brightness levels. This will provide an estimate of above-ground green biomass with multispectral imagery.

  18. Effects of migratory geese on plant communities of an Alaskan salt marsh

    USGS Publications Warehouse

    Zacheis, A.; Hupp, J.W.; Ruess, R.W.

    2001-01-01

    1. We studied the effects of lesser snow geese (Anser caerulescens caerulescens) and Canada geese (Branta canadensis) on two salt marsh plant communities in Cook Inlet, Alaska, a stopover area used during spring migration. From 1995 to 1997 we compared plant species composition and biomass on plots where geese were excluded from feeding with paired plots where foraging could occur. 2. Foraging intensity was low (650-1930 goose-days km-2) compared to other goose-grazing systems. 3. Canada geese fed mainly on above-ground shoots of Triglochin maritimum, Puccinellia spp. and Carex ramenskii, whereas the majority of the snow goose diet consisted of below-ground tissues of Plantago maritima and Triglochin maritimum. 4. Plant communities responded differently to goose herbivory. In the sedge meadow community, where feeding was primarily on above-ground shoots, there was no effect of grazing on the dominant species Carex ramenskii and Triglochin maritimum. In the herb meadow community, where snow geese fed on Plantago maritima roots and other below-ground tissues, there was a difference in the relative abundance of plant species between treatments. Biomass of Plantago maritima and Potentilla egedii was lower on grazed plots compared with exclosed, whereas biomass of Carex ramenskii was greater on grazed plots. There was no effect of herbivory on total standing crop biomass in either community. The variable effect of herbivory on Carex ramenskii between communities suggests that plant neighbours and competitive interactions are important factors in a species' response to herbivory. In addition, the type of herbivory (above- or below-ground) was important in determining plant community response to herbivory. 5. Litter accumulation was reduced in grazed areas compared with exclosed in both communities. Trampling of the previous year's litter into the soil surface by geese incorporated more litter into soils in grazed areas. 6. This study illustrates that even light herbivore

  19. Effects of phosphate and thiosulphate on arsenic accumulation in Brassica juncea plants grown in soil and in hydroponic culture

    NASA Astrophysics Data System (ADS)

    Pezzarossa, Beatrice; Petruzzelli, Gianniantonio; Grifoni, Martina; Rosellini, Irene; Malagoli, Mario; Schiavon, Michela

    2013-04-01

    Arsenic is recognised as a toxic metalloid and a strong pollutant in soils of many countries. Thus, the reclamation of contaminated areas is fundamental in order to protect both human health and agricultural production. This study is focused on the assisted phytoextraction, a technology for reclaiming polluted soils that takes advantage of the capability of some plants to extract inorganic elements from soils with the aid of additive agents. The nutrients phosphorus, as phosphate, and sulphur, as thiosulphate, can compete with the form more oxidised of arsenic, both in soil and plant. This study examined the capability of thiosulphate (Th) and phosphate (Ph) to promote the release of As from soil surfaces in order to improve the phytoavailability and thus the absorption of As by Brassica juncea plants. In the first experiment B. juncea plants were grown on a soil that had been sampled from an industrial area strongly contaminated by As (790 mg As kg-1 soil). The second experiment was carried out in hydroponics where As has been added at a concentration (100 microM) similar to the As available concentration measured in soil. In both trials ammonium thiosulphate (at the concentration of 0.27 M in soil, and 400 microM in hydroponics) and potassium hydrogen phosphate (at the concentration of 0.05 M in soil, and 112 microM in hydroponics) were added. The biomass of B. juncea was determined and the accumulation of P, S and As in root and in the above-ground tissues have been analyzed. Our results showed that thiosulphate and phosphate acted either as nutrients and detoxifying agents, due to the stimulation of plant defensive systems, and influenced either the biomass production and the As accumulation in plant tissues. In the plants grown in soil, As accumulated at higher levels in the above-ground part than in the roots and the addition of Th induced a higher biomass production and a higher total As accumulation (concentration x biomass) in the above-ground tissues

  20. Gallic acid, one of the components in many plant tissues, is a potential inhibitor for insulin amyloid fibril formation.

    PubMed

    Jayamani, Jayaraman; Shanmugam, Ganesh

    2014-10-01

    Proteins under stressful conditions can lead to the formation of an ordered self-assembled structure, referred to as amyloid fibrils, to which many neurodegenerative diseases such as Type II diabetes, Alzheimer's, Parkinson's, Huntington's, etc., are attributed. Inhibition of amyloid fibril formation using natural products is one of the main therapeutic strategies to prevent the progression of these diseases. Polyphenols are the mostly consumed as antioxidants in a human nutrition. Herein, we have studied the effect of a simple polyphenol, gallic acid (GA), one of the main components in plant tissues, especially in tea leaves, on the insulin amyloid fibril formation. Different biophysical characterizations such as turbidity, atomic force microscopy (AFM), Thioflavin T (ThT) assays, circular dichroism, and Fourier transform-infrared spectroscopy have been used to analyze the inhibition of amyloid fibril formation. The occurrence of fibrils in an AFM image and ThT fluorescence enhancement confirms the formation of insulin amyloid fibrils when incubated under acidic pH 2 at 65 °C. In the presence of GA, absence of fibrils in AFM image and no change in the intensity of ThT fluorescence confirms the inhibition of insulin amyloid fibrils by GA. Spectroscopic results reveal that GA inhibits the conformational transition of α-helix → β-sheet, which is generally induced during the insulin fibril formation. It was found that the inhibitory effect of GA is concentration dependent and non-linear. Based on the observed results, we propose that GA interacts with native insulin, preventing nuclei formation, which is essential for fibril growth, thereby inhibiting the amyloid fibril formation. The present results thus demonstrate that GA can effectively inhibit insulin amyloid fibril formation in vitro. PMID:25105923

  1. Aboveground net primary production responses to water availability in the Chihuhuan Desert: importance of legacy effects

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In arid ecosystems, current year precipitation explains a small proportion of annual aboveground net primary production (ANPP). Precipitation that occurred in previous years may be responsible for the observed difference between actual and expected ANPP, a concept that we called legacy. Thus, previo...

  2. Technical basis for the aboveground structure failure and associated represented hazardous conditions

    SciTech Connect

    MANGAN, D.

    2003-03-20

    The purpose of the Technical Basis Document is to determine the consequences and frequency of aboveground structure failures. These failures include drops of contained equipment, such as a pump, from a SST or DST, a crane failure resulting in a load drop onto a HEPA filter. These failures can result in an uncontrolled release of radiological and toxicological material.

  3. Final Harvest of Above-Ground Biomass and Allometric Analysis of the Aspen FACE Experiment

    SciTech Connect

    Mark E. Kubiske

    2013-04-15

    The Aspen FACE experiment, located at the US Forest Service Harshaw Research Facility in Oneida County, Wisconsin, exposes the intact canopies of model trembling aspen forests to increased concentrations of atmospheric CO2 and O3. The first full year of treatments was 1998 and final year of elevated CO2 and O3 treatments is scheduled for 2009. This proposal is to conduct an intensive, analytical harvest of the above-ground parts of 24 trees from each of the 12, 30 m diameter treatment plots (total of 288 trees) during June, July & August 2009. This above-ground harvest will be carefully coordinated with the below-ground harvest proposed by D.F. Karnosky et al. (2008 proposal to DOE). We propose to dissect harvested trees according to annual height growth increment and organ (main stem, branch orders, and leaves) for calculation of above-ground biomass production and allometric comparisons among aspen clones, species, and treatments. Additionally, we will collect fine root samples for DNA fingerprinting to quantify biomass production of individual aspen clones. This work will produce a thorough characterization of above-ground tree and stand growth and allocation above ground, and, in conjunction with the below ground harvest, total tree and stand biomass production, allocation, and allometry.

  4. Switchgrass and intermediate wheatgrass aboveground and belowground response to nitrogen and calcium

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Optimal nutrient management will be critical in developing sustainable perennial biofeedstocks. Calcium (Ca) and nitrogen (N) treatments (2, 8, and 32 mg L-1) were investigated on aboveground and belowground growth of switchgrass (Panicum virgatum L.) and intermediate wheatgrass [Thinopyrum interme...

  5. Impact of predatory carabids on below- and aboveground pests and yield in strawberry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The impact of adult carabid beetles on below- and above-ground pests and fruit yield was examined in a two-year strawberry field study. Plots (2 m x 2 m) enclosed with barriers were used to augment or exclude adult carabids, and compared to open control plots. Pterostichus melanarius was the predo...

  6. Use of Radar to Estimate Above-Ground Biomass in Disturbed Tropical Landscapes

    NASA Technical Reports Server (NTRS)

    Houghton, R. A.

    1998-01-01

    The overall purpose of this work was to evaluate the use of satellite radar in distinguishing, first, different cover classes in tropical landscapes and, second, cover classes with different amounts of above-ground biomass. The work focused on Ama7onian forests around Paragominas, Para, Brazil where extensive ground data had been obtained through previous field work.

  7. Characteristics of train noise in above-ground and underground stations with side and island platforms

    NASA Astrophysics Data System (ADS)

    Shimokura, Ryota; Soeta, Yoshiharu

    2011-04-01

    Railway stations can be principally classified by their locations, i.e., above-ground or underground stations, and by their platform styles, i.e., side or island platforms. However, the effect of the architectural elements on the train noise in stations is not well understood. The aim of the present study is to determine the different acoustical characteristics of the train noise for each station style. The train noise was evaluated by (1) the A-weighted equivalent continuous sound pressure level ( LAeq), (2) the amplitude of the maximum peak of the interaural cross-correlation function (IACC), (3) the delay time ( τ1) and amplitude ( ϕ1) of the first maximum peak of the autocorrelation function. The IACC, τ1 and ϕ1 are related to the subjective diffuseness, pitch and pitch strength, respectively. Regarding the locations, the LAeq in the underground stations was 6.4 dB higher than that in the above-ground stations, and the pitch in the underground stations was higher and stronger. Regarding the platform styles, the LAeq on the side platforms was 3.3 dB higher than on the island platforms of the above-ground stations. For the underground stations, the LAeq on the island platforms was 3.3 dB higher than that on the side platforms when a train entered the station. The IACC on the island platforms of the above-ground stations was higher than that in the other stations.

  8. A study on estimation of aboveground wet biomass based on the microwave vegetation indices

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vegetation biomass is an important parameter in the carbon cycle study. In this paper, a new technique to estimate aboveground vegetation wet biomass based on the Microwave Vegetation Indices (MVIs), which are computed through the observed brightness temperature of AMSR-E/Aqua under two adjacent fre...

  9. Above-ground biomass of mangrove species. I. Analysis of models

    NASA Astrophysics Data System (ADS)

    Soares, Mário Luiz Gomes; Schaeffer-Novelli, Yara

    2005-10-01

    This study analyzes the above-ground biomass of Rhizophora mangle and Laguncularia racemosa located in the mangroves of Bertioga (SP) and Guaratiba (RJ), Southeast Brazil. Its purpose is to determine the best regression model to estimate the total above-ground biomass and compartment (leaves, reproductive parts, twigs, branches, trunk and prop roots) biomass, indirectly. To do this, we used structural measurements such as height, diameter at breast-height (DBH), and crown area. A combination of regression types with several compositions of independent variables generated 2.272 models that were later tested. Subsequent analysis of the models indicated that the biomass of reproductive parts, branches, and prop roots yielded great variability, probably because of environmental factors and seasonality (in the case of reproductive parts). It also indicated the superiority of multiple regression to estimate above-ground biomass as it allows researchers to consider several aspects that affect above-ground biomass, specially the influence of environmental factors. This fact has been attested to the models that estimated the biomass of crown compartments.

  10. Effects of Long-Term Trampling on the Above-Ground Forest Vegetation and Soil Seed Bank at the Base of Limestone Cliffs

    NASA Astrophysics Data System (ADS)

    Rusterholz, Hans-Peter; Verhoustraeten, Christine; Baur, Bruno

    2011-11-01

    Exposed limestone cliffs in central Europe harbor a highly divers flora with many rare and endangered species. During the past few decades, there has been increasing recreational use of these cliffs, which has caused local environmental disturbances. Successful restoration strategies hinge on identifying critical limitations. We examined the composition of aboveground forest vegetation and density and species composition of seeds in the soil seed bank at the base of four limestone cliffs in mixed deciduous forests that are intensively disturbed by human trampling and at four undisturbed cliffs in the Jura Mountains in northwestern Switzerland. We found that long-term human trampling reduced total aboveground vegetation cover at the base of cliffs and caused a significant shift in the plant-species composition. Compared with undisturbed cliffs, total seed density was lower in disturbed cliffs. Human trampling also altered the species composition of seeds in the soil seed bank. Seeds of unintentionally introduced, stress-tolerant, and ruderal species dominated the soil seed bank at the base of disturbed cliffs. Our findings indicate that a restoration of degraded cliff bases from the existing soil seed bank would result in a substantial change of the original unique plant composition. Active seed transfer, or seed flux from adjacent undisturbed forest areas, is essential for restoration success.

  11. Decoloration and solubilization of plant tissue prior to determination of /sup 3/H, /sup 14/C, and /sup 35/S by liquid scintillation

    SciTech Connect

    Smith, I.K.; Lang, A.L.

    1987-08-01

    A method is described for the decoloration and partial solubilization of plant tissue with 2% sodium hypochlorite. Following treatment of the digest with ammonia, the samples are suitable for the determination of /sup 3/H, /sup 14/C, and /sup 35/S by liquid scintillation counting. The color quenching is negligible and counting efficiencies are high: 30-40% for /sup 3/H and 90-95% for /sup 14/C.

  12. Estimating above-ground carbon biomass in a newly restored coastal plain wetland using remote sensing.

    PubMed

    Riegel, Joseph B; Bernhardt, Emily; Swenson, Jennifer

    2013-01-01

    Developing accurate but inexpensive methods for estimating above-ground carbon biomass is an important technical challenge that must be overcome before a carbon offset market can be successfully implemented in the United States. Previous studies have shown that LiDAR (light detection and ranging) is well-suited for modeling above-ground biomass in mature forests; however, there has been little previous research on the ability of LiDAR to model above-ground biomass in areas with young, aggrading vegetation. This study compared the abilities of discrete-return LiDAR and high resolution optical imagery to model above-ground carbon biomass at a young restored forested wetland site in eastern North Carolina. We found that the optical imagery model explained more of the observed variation in carbon biomass than the LiDAR model (adj-R(2) values of 0.34 and 0.18 respectively; root mean squared errors of 0.14 Mg C/ha and 0.17 Mg C/ha respectively). Optical imagery was also better able to predict high and low biomass extremes than the LiDAR model. Combining both the optical and LiDAR improved upon the optical model but only marginally (adj-R(2) of 0.37). These results suggest that the ability of discrete-return LiDAR to model above-ground biomass may be rather limited in areas with young, small trees and that high spatial resolution optical imagery may be the better tool in such areas. PMID:23840837

  13. Estimating Above-Ground Carbon Biomass in a Newly Restored Coastal Plain Wetland Using Remote Sensing

    PubMed Central

    Riegel, Joseph B.; Bernhardt, Emily; Swenson, Jennifer

    2013-01-01

    Developing accurate but inexpensive methods for estimating above-ground carbon biomass is an important technical challenge that must be overcome before a carbon offset market can be successfully implemented in the United States. Previous studies have shown that LiDAR (light detection and ranging) is well-suited for modeling above-ground biomass in mature forests; however, there has been little previous research on the ability of LiDAR to model above-ground biomass in areas with young, aggrading vegetation. This study compared the abilities of discrete-return LiDAR and high resolution optical imagery to model above-ground carbon biomass at a young restored forested wetland site in eastern North Carolina. We found that the optical imagery model explained more of the observed variation in carbon biomass than the LiDAR model (adj-R2 values of 0.34 and 0.18 respectively; root mean squared errors of 0.14 Mg C/ha and 0.17 Mg C/ha respectively). Optical imagery was also better able to predict high and low biomass extremes than the LiDAR model. Combining both the optical and LiDAR improved upon the optical model but only marginally (adj-R2 of 0.37). These results suggest that the ability of discrete-return LiDAR to model above-ground biomass may be rather limited in areas with young, small trees and that high spatial resolution optical imagery may be the better tool in such areas. PMID:23840837

  14. Plant tissue-based chemiluminescence flow biosensor for determination of unbound dopamine in rabbit blood with on-line microdialysis sampling.

    PubMed

    Li, Baoxin; Zhang, Zhujun; Jin, Yan

    2002-06-01

    A novel plant tissue-based chemiluminescence (CL) biosensor for dopamine combined with flow injection analysis is presented in this paper. The potato roots act as molecular recognition elements. Dopamine is oxidized by oxygen under the catalysis of polyphenol oxidase in the tissue column to produce hydrogen peroxide, which can react with luminol in the presence of peroxidase of potato tissue to generate CL signal. The CL emission intensity was linear with dopamine concentration in the range of 1x10(-5)-1x10(-7) g/ml and the detection limit was 5.3x10(-8) g/ml (3sigma) with a relative standard deviation of 1.7%. Combined with microdialysis sampling, the biosensor was applied to monitor the variation of dopamine level in the blood of rabbit after the administration of dopamine to demonstrate the favorable resolution and reliability of the system for in vivo on-line monitoring. PMID:11959481

  15. Effects of micro electric current load during cooling of plant tissues on intracellular ice crystal formation behavior and pH.

    PubMed

    Ninagawa, Takako; Kawamura, Yukio; Konishi, Tadashi; Narumi, Akira

    2016-08-01

    Cryopreservation techniques are expected to evolve further to preserve biomaterials and foods in a fresh state for extended periods of time. Long-term cryopreservation of living materials such as food and biological tissue is generally achieved by freezing; thus, intracellular freezing occurs. Intracellular freezing injures the cells and leads to cell death. Therefore, a dream cryopreservation technique would preserve the living materials without internal ice crystal formation at a temperature low enough to prevent bacterial activity. This study was performed to investigate the effect of micro electrical current loading during cooling as a new cryopreservation technique. The behavior of intracellular ice crystal formation in plant tissues with or without an electric current load was evaluated using the degree of supercooling, degree of cell deformation, and grain size and growing rate of intracellular ice crystal. Moreover, the transition of intracellular pH during plant tissue cooling with or without electric current loading was also examined using the fluorescence intensity ratio to comprehend cell activity at lower temperatures. The results indicated that micro electric current load did not only decrease the degree of cell deformation and grain size of intracellular ice crystal but also reduced the decline in intracellular pH due to temperature lowering, compared with tissues subjected to the same cooling rate without an electric current load. Thus, the effect of electric current load on cryopreservation and the potential of a new cryopreservation technique using electric current load were discussed based on these results. PMID:27343137

  16. Plant material features responsible for bamboo's excellent mechanical performance: a comparison of tensile properties of bamboo and spruce at the tissue, fibre and cell wall levels

    PubMed Central

    Wang, Xiaoqing; Keplinger, Tobias; Gierlinger, Notburga; Burgert, Ingo

    2014-01-01

    Background and Aims Bamboo is well known for its fast growth and excellent mechanical performance, but the underlying relationships between its structure and properties are only partially known. Since it lacks secondary thickening, bamboo cannot use adaptive growth in the same way as a tree would in order to modify the geometry of the stem and increase its moment of inertia to cope with bending stresses caused by wind loads. Consequently, mechanical adaptation can only be achieved at the tissue level, and this study aims to examine how this is achieved by comparison with a softwood tree species at the tissue, fibre and cell wall levels. Methods The mechanical properties of single fibres and tissue slices of stems of mature moso bamboo (Phyllostachys pubescens) and spruce (Picea abies) latewood were investigated in microtensile tests. Cell parameters, cellulose microfibril angles and chemical composition were determined using light and electron microscopy, wide-angle X-ray scattering and confocal Raman microscopy. Key Results Pronounced differences in tensile stiffness and strength were found at the tissue and fibre levels, but not at the cell wall level. Thus, under tensile loads, the differing wall structures of bamboo (multilayered) and spruce (sandwich-like) appear to be of minor relevance. Conclusions The superior tensile properties of bamboo fibres and fibre bundles are mainly a result of amplified cell wall formation, leading to a densely packed tissue, rather than being based on specific cell wall properties. The material optimization towards extremely compact fibres with a multi-lamellar cell wall in bamboo might be a result of a plant growth strategy that compensates for the lack of secondary thickening growth at the tissue level, which is not only favourable for the biomechanics of the plant but is also increasingly utilized in terms of engineering products made from bamboo culms. PMID:25180290

  17. A family of transcripts encoding water channel proteins: tissue-specific expression in the common ice plant.

    PubMed Central

    Yamada, S; Katsuhara, M; Kelly, W B; Michalowski, C B; Bohnert, H J

    1995-01-01

    Seawater-strength salt stress of the ice plant (Mesembryanthemum crystallinum) initially results in wilting, but full turgor is restored within approximately 2 days. We are interested in a mechanistic explanation for this behavior and, as a requisite for in-depth biochemical studies, have begun to analyze gene expression changes in roots coincident with the onset of stress. cDNAs that suggested changes in mRNA amount under stress were found; their deduced amino acid sequences share homologies with proteins of the Mip (major intrinsic protein) gene family and potentially encode aquaporins. One transcript, MipB, was found only in root RNA, whereas two other transcripts, MipA and MipC, were detected in roots and leaves. Transcript levels of MipB were of low abundance. All transcripts declined initially during salt stress but later recovered to at least prestress level. The most drastic decline was in MipA and MipC transcripts. MipA mRNA distribution in roots detected by in situ hybridization indicated that the transcript was present in all cells in the root tip. In the expansion zone of the root where vascular bundles differentiate, MipA transcript amounts were most abundant in the endodermis. In older roots, which had undergone secondary growth, MipA was highly expressed in cell layers surrounding individual xylem strands. MipA was also localized in leaf vascular tissue and, in lower amounts, in mesophyll cells. Transcripts for MipB seemed to be present exclusively in the tip of the root, in a zone before and possibly coincident with the development of a vascular system. MipA- and MipB-encoded proteins expressed in Xenopus oocytes led to increased water permeability. mRNA fluctuations of the most highly expressed MipA and MipC coincided with turgor changes in leaves under stress. As the leaves regained turgor, transcript levels of these water channel proteins increased. PMID:7549476

  18. Variability of above-ground litter inputs alters soil physicochemical and biological processes: a meta-analysis of litterfall-manipulation experiments

    NASA Astrophysics Data System (ADS)

    Xu, S.; Liu, L. L.; Sayer, E. J.

    2013-11-01

    Global change has been shown to alter the amount of above-ground litter inputs to soil greatly, which could cause substantial cascading effects on below-ground biogeochemical cycling. Despite extensive study, there is uncertainty about how changes in above-ground litter inputs affect soil carbon and nutrient turnover and transformation. Here, we conducted a meta-analysis on 70 litter-manipulation experiments in order to assess how changes in above-ground litter inputs alter soil physicochemical properties, carbon dynamics and nutrient cycles. Our results demonstrated that litter removal decreased soil respiration by 34%, microbial biomass carbon in the mineral soil by 39% and total carbon in the mineral soil by 10%, whereas litter addition increased them by 31, 26 and 10%, respectively. This suggests that greater litter inputs increase the soil carbon sink despite higher rates of carbon release and transformation. Total nitrogen and extractable inorganic nitrogen in the mineral soil decreased by 17 and 30%, respectively, under litter removal, but were not altered by litter addition. Overall, litter manipulation had a significant impact upon soil temperature and moisture, but not soil pH; litter inputs were more crucial in buffering soil temperature and moisture fluctuations in grassland than in forest. Compared to other ecosystems, tropical and subtropical forests were more sensitive to variation in litter inputs, as altered litter inputs affected the turnover and accumulation of soil carbon and nutrients more substantially over a shorter time period. Our study demonstrates that although the magnitude of responses differed greatly among ecosystems, the direction of the responses was very similar across different ecosystems. Interactions between plant productivity and below-ground biogeochemical cycling need to be taken into account to predict ecosystem responses to environmental change.

  19. Evaluation of in vivo detection properties of 22Na, 65Zn, 86Rb, 109Cd and 137Cs in plant tissues using real-time radioisotope imaging system

    NASA Astrophysics Data System (ADS)

    Sugita, Ryohei; Kobayashi, Natsuko I.; Hirose, Atsushi; Tanoi, Keitaro; Nakanishi, Tomoko M.

    2014-02-01

    In plant research, radioisotope imaging provides useful information about physiological activities in various tissues and elemental transport between plant organs. To expand the usage of imaging techniques, a new system was developed to visualize beta particles, x-rays and gamma-rays emitted from plant bodies. This real-time radioisotope imaging system (RRIS) visualizes radioactivity after conversion into light with a CsI(Tl) scintillator plate. Herein, the RRIS detection properties of the gamma-ray emitters 22Na, 65Zn, 86Rb, 109Cd and 137Cs were evaluated in comparison with those of radioluminography (RLG) using an imaging plate. The lower quantitative detection limit (Bq mm-2) during a 15 min period ranged from 0.1 to 4, depending on the nuclide, similar to that of RLG. When the quantitative ability to detect radiation from various Arabidopsis tissues was analyzed, the quantitative capability in silique and the thick internode tended to be low. In an EGS5 simulation, beta particles were the greatest contributors to RRIS imaging of 22Na, 86Rb and 137Cs, and low-energy x-rays contributed significantly to 65Zn and 109Cd detection. Thus, both self-absorption and air space between the sample and scintillator surface could impair quantitative RRIS imaging. Despite these issues, RRIS is suggested for quantitative time-course measurements of radionuclide motion within plants.

  20. Aboveground and belowground effects of single-tree removals in New Zealand rain forest.

    PubMed

    Wardle, David A; Wiser, Susan K; Allen, Robert B; Doherty, James E; Bonner, Karen I; Williamson, Wendy M

    2008-05-01

    There has been considerable recent interest in how human-induced species loss affects community and ecosystem properties. These effects are particularly apparent when a commercially valuable species is harvested from an ecosystem, such as occurs through single-tree harvesting or selective logging of desired timber species in natural forests. In New Zealand mixed-species rain forests, single-tree harvesting of the emergent gymnosperm Dacrydium cupressinum, or rimu, has been widespread. This harvesting has been contentious in part because of possible ecological impacts of Dacrydium removal on the remainder of the forest, but many of these effects remain unexplored. We identified an area where an unintended 40-year "removal experiment" had been set up that involved selective extraction of individual Dacrydium trees. We measured aboveground and belowground variables at set distances from both individual live trees and stumps of trees harvested 40 years ago. Live trees had effects both above and below ground by affecting diversity and cover of several components of the vegetation (usually negatively), promoting soil C sequestration, enhancing ratios of soil C:P and N:P, and affecting community structure of soil microflora. These effects extended to 8 m from the tree base and were likely caused by poor-quality litter and humus produced by the trees. Measurements for the stumps revealed strong legacy effects of prior presence of trees on some properties (e.g., cover by understory herbs and ferns, soil C sequestration, soil C:P and N:P ratios), but not others (e.g., soil fungal biomass, soil N concentration). These results suggest that the legacy of prior presence of Dacrydium may remain for several decades or centuries, and certainly well over 40 years. They also demonstrate that, while large Dacrydium individuals (and their removal) may have important effects in their immediate proximity, within a forest, these effects should only be important in localized patches

  1. Analysis of 2,4,6-trinitrotoluene and its transformation products in soils and plant tissues by high-performance liquid chromatography

    SciTech Connect

    Harvey, S.D.; Fellows, R.J.; Cataldo, D.A.; Bean, R.M. )

    1990-01-01

    Previous studies have failed to provide an acceptable mass balance for 2,4,6-trinitrotoluene (TNT) in soils and plants due to deficiencies in analytical methodology. A high-performance liquid chromatographic (HPLC) method for soil analysis is reported which allowed for a mass balance in excess of 88% during a 2-month study. A method for plant analysis was developed which involved fractionation of organic extracts on Florisil adsorbent, to remove interfering pigments, followed by HPLC analysis of TNT and the primary metabolites, 2-amino-4,6-dinitrotoluene and 4-amino-2,6-dinitrotoluene. Chromatographic recovery of TNT from spiked tissues was 85{plus minus}6%. The methodology was utilized to investigate TNT uptake and metabolism in plants grown in TNT hydroponic solutions.

  2. Characterization of plant-growth-promoting effects and concurrent promotion of heavy metal accumulation in the tissues of the plants grown in the polluted soil by Burkholderia strain LD-11.

    PubMed

    Huang, Gui-Hai; Tian, Hui-Hui; Liu, Hai-Ying; Fan, Xian-Wei; Liang, Yu; Li, You-Zhi

    2013-01-01

    Plant-growth-promoting (PGP) bacteria especially with the resistance to multiple heavy metals are helpful to phytoremediation. Further development of PGP bacteria is very necessary because of the extreme diversity of plants, soils, and heavy metal pollution. A Burkholderia sp. strain, numbered LD-11, was isolated, which showed resistances to multiple heavy metals and antibiotics. It can produce indole-3-acetic acid, 1-aminocyclopropane-1-carboxylic acid deaminase and siderophores. Inoculation with the LD-11 improved germination of seeds of the investigated vegetable plants in the presence of Cu, promoted elongation of roots and hypocotyledonary axes, enhanced the dry weights of the plants grown in the soils polluted with Cu and/or Pb, and increased activity of the soil urease and the rhizobacteria diversity. Inoculation with the LD-11 significantly enhanced Cu and/or Pb accumulation especially in the roots of the plants grown in the polluted soils. Notably, LD-11 could produce siderophores in the presence of Cu. Conclusively, the PGP effects and concurrent heavy metal accumulation in the plant tissues results from combined effects of the above-mentioned multiple factors. Cu is an important element that represses production of the siderophore by the bacteria. Phytoremediation by synergistic use of the investigated plants and the bacterial strain LD-11 is a phytoextraction process. PMID:23819291

  3. A rapid and robust assay for detection of S-phase cell cycle progression in plant cells and tissues by using ethynyl deoxyuridine

    PubMed Central

    2010-01-01

    Background Progress in plant cell cycle research is highly dependent on reliable methods for detection of cells replicating DNA. Frequency of S-phase cells (cells in DNA synthesis phase) is a basic parameter in studies on the control of cell division cycle and the developmental events of plant cells. Here we extend the microscopy and flow cytometry applications of the recently developed EdU (5-ethynyl-2'-deoxyuridine)-based S-phase assay to various plant species and tissues. We demonstrate that the presented protocols insure the improved preservation of cell and tissue structure and allow significant reduction in assay duration. In comparison with the frequently used detection of bromodeoxyuridine (BrdU) and tritiated-thymidine incorporation, this new methodology offers several advantages as we discuss here. Results Applications of EdU-based S-phase assay in microscopy and flow cytometry are presented by using cultured cells of alfalfa, Arabidopsis, grape, maize, rice and tobacco. We present the advantages of EdU assay as compared to BrdU-based replication assay and demonstrate that EdU assay -which does not require plant cell wall digestion or DNA denaturation steps, offers reduced assay duration and better preservation of cellular, nuclear and chromosomal morphologies. We have also shown that fast and efficient EdU assay can also be an efficient tool for dual parameter flow cytometry analysis and for quantitative assessment of replication in thick root samples of rice. Conclusions In plant cell cycle studies, EdU-based S-phase detection offers a superior alternative to the existing S-phase assays. EdU method is reliable, versatile, fast, simple and non-radioactive and it can be readily applied to many different plant systems. PMID:20181034

  4. Novel use of positively charged nylon transfer membranes for trapping indoleacetic acid or other small anions during efflux from plant tissues

    NASA Technical Reports Server (NTRS)

    Evans, M. L.; Hangarter, R. P.

    1993-01-01

    Positively charged nylon blotting membranes were used as an anion binding medium to trap [14C]indoleactic acid (IAA) as it exited cells at the basal ends of Coleus blumei L. stem and Zea mays L. coleoptile segments. Autoradiography was used to visualize where the [14C] that moved out of the cut ends was localized on the nylon membrane. Diffusion of [14C]IAA from the initial point of contact with the nylon membrane was minimal. Comparison of the autoradiograms with anatomical tissue prints of the cut ends of the segments was used to determine what tissues participate in IAA movement. The results of these initial studies were consistent with other reports suggesting that [14C]IAA movement was primarily associated with vascular tissues in both C. blumei stems and corn coleoptiles, but the resolution was not sufficient to identify which vascular tissues were involved in IAA transport. With further refinements, this technique could also be used for studying the movement of other small charged molecules through plant tissues.

  5. Enhancement of heavy metal accumulation by tissue specific co-expression of iaaM and ACC deaminase genes in plants.

    PubMed

    Zhang, Yong; Zhao, Lihong; Wang, Yao; Yang, Baoyu; Chen, Shiyun

    2008-06-01

    1-Aminocyclopropane deaminase (ACC) and tryptophan monooxygenase are two enzymes involved in plant senescence-inhibiting and growth-promoting regulation, respectively. In this study, two binary vectors were constructed in which the Agrobacterium iaaM gene was under the transcriptional control of a xylem-specific glycine-rich protein promoter alone, or co-expressed with the bacterial ACC deaminase gene, which was driven by the constitutive CaMV 35S promoter. Transgenic petunia shoots co-expressing both genes were able to root on medium supplemented with 7.5 mg l(-1) CoCl2. When T1 transgenic tobacco plants were grown in sand supplemented with Cu2+ and Co2+, tissue specific co-expression of both iaaM and ACC deaminase genes showed faster growth with larger biomass with a more extensive root system, and accumulated a greater amount of heavy metals than the empty vector control plants. When T1 transgenic tobacco plants were grown in soil watered with different concentrations of CuSO4, xylem specific expression of the iaaM gene caused the accumulation of more Cu2+ than the empty vector control at lower CuSO4 concentrations, but showed severe toxic symptoms at concentration of 100 mg l(-1) CuSO4. T1 transgenic plants co-expressing both genes accumulated more heavy metals into the plant shoots and can tolerate CuSO4 at 150 mg l(-1). In addition, plants co-expressing these two genes can grow well in a complex contaminated soil containing both inorganic and organic pollutants, while the growth of the control plants was greatly inhibited. PMID:18471863

  6. Acetone enhances the direct analysis of total condensed tannins in plant tissues by the butanol-HCl-iron assay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The butanol-HCl spectrophotometric assay is widely used to quantify extractable and insoluble forms of condensed tannin (CT, syn. proanthocyanidin) in foods, feeds, and foliage of herbaceous and woody plants. However, this method underestimates total CT content when applied directly to plant materia...

  7. Regeneration of flax ( Linum usitatissimum L.) plants from anther culture and somatic tissue with increased resistance to Fusarium oxysporum.

    PubMed

    Rutkowska-Krause, I; Mankowska, G; Lukaszewicz, M; Szopa, J

    2003-09-01

    The aim of this study was to establish a protocol for the efficient production of flax plants of microspore origin. The results were compared to those obtained for plants regenerated from somatic explants from hypocotyls, cotyledons, leaves, stems and roots. All the plants obtained during the experiments were regenerated from callus that was grown for periods from a few weeks to a few months before the regeneration was achieved. Anther cultures were less effective in plant regeneration than somatic cell cultures. However, regenerants derived from anther cells showed valuable breeding features, including increased resistance to fungal wilt. The age of the donor plants and the season they grew in had a noticeable effect on their anther callusing and subsequent plant regeneration. Low temperature had a negative effect and dark pre-treatment a positive effect on callusing and plant regeneration. Different media were most effective for callus induction, shoot induction and rooting. For callus induction two carbon sources (2.5% sucrose and 2.5% glucose) were most effective; for shoots, only sucrose at lower concentration (2%) was effective. Rooting was most efficient in 1% sucrose and reduced (50%) mineral concentration in the medium. It was found that the length of in vitro cultivation significantly increases the ploidy and affects such features as regenerant morphological characteristics, petal colour, and resistance to Fusarium oxysporum-induced fungal wilt. The established plant regeneration system provides a basis for the creation of transgenic flax. PMID:12827441

  8. Plant DNA detection from grasshopper guts: A step-by-step protocol, from tissue preparation to obtaining plant DNA sequences1

    PubMed Central

    Avanesyan, Alina

    2014-01-01

    • Premise of the study: A PCR-based method of identifying ingested plant DNA in gut contents of Melanoplus grasshoppers was developed. Although previous investigations have focused on a variety of insects, there are no protocols available for plant DNA detection developed for grasshoppers, agricultural pests that significantly influence plant community composition. • Methods and Results: The developed protocol successfully used the noncoding region of the chloroplast trnL (UAA) gene and was tested in several feeding experiments. Plant DNA was obtained at seven time points post-ingestion from whole guts and separate gut sections, and was detectable up to 12 h post-ingestion in nymphs and 22 h post-ingestion in adult grasshoppers. • Conclusions: The proposed protocol is an effective, relatively quick, and low-cost method of detecting plant DNA from the grasshopper gut and its different sections. This has important applications, from exploring plant “movement” during food consumption, to detecting plant–insect interactions. PMID:25202604

  9. Femtosecond near-infrared laser pulses as a versatile non-invasive tool for intra-tissue nanoprocessing in plants without compromising viability.

    PubMed

    Tirlapur, Uday K; König, Karsten

    2002-08-01

    In this report, we describe a highly reproducible femtosecond near-infrared (NIR) laser-based nanoprocessing technique that can be used both for non-invasive intra-tissue nanodissection of plant cell walls as well as selective destruction of a single plastid or part thereof without compromising the viability of the cells. The ultra-precise intra-tissue nanoprocessing is achieved by the generation of high light intensity (10(12)W cm(-2)) by diffraction-limited focusing of the radiation of an NIR (lambda = 740 and 800 nm) femtosecond titanium-sapphire laser to a sub-femtolitre volume and subsequent highly localized instantaneous plasma formation. Following nanosurgery, electron microscopical analysis of the corresponding cellular target areas revealed clean non-staggering lesions across the cell wall with a cut width measuring less than 400 nm. To our knowledge, this is the smallest cut made non-invasively within a plant tissue. Further evidence, including two-photon imaging of chlorophyll fluorescence, revealed that a single target chloroplast or part thereof can be completely knocked out using intense ultra-fast NIR pulses without any visible deleterious effect on the adjacent plastids. The vitality of the cells after nanoprocessing has been ascertained by exclusion of propidium iodide from the cells as well as by the presence of cytoplasmic streaming. The potential applications of this technical advance include developmental biology applications, particularly studies addressing spatio-temporal control of ontogenetic events and cell-cell interactions, and gravitational biology applications. PMID:12164815

  10. Molecular chemistry of plant protein structure at a cellular level by synchrotron-based FTIR spectroscopy: Comparison of yellow ( Brassica rapa) and Brown ( Brassica napus) canola seed tissues

    NASA Astrophysics Data System (ADS)

    Yu, Peiqiang

    2008-05-01

    The objective of this study was to use synchrotron light sourced FTIR microspectroscopy as a novel approach to characterize protein molecular structure of plant tissue: compared yellow and brown Brassica canola seed within cellular dimensions. Differences in the molecular chemistry and the structural-chemical characteristics were identified between two type of plant tissues. The yellow canola seeds contained a relatively lower (P < 0.05) percentage of model-fitted α-helices (33 vs. 37), a higher (P < 0.05) relative percentage of model-fitted β-sheets (27 vs. 21) and a lower (P < 0.05) ratio of α-helices to β-sheets (1.3 vs. 1.9) than the brown seeds. These results may indicate that the protein value of the yellow canola seeds as food or feed was different from that of the brown canola seeds. The cluster analysis and principal component analysis did not show clear differences between the yellow and brown canola seed tissues in terms of protein amide I structures, indicating they are related to each other. Both yellow and brown canola seeds contain the same proteins but in different ratios.

  11. A geminivirus replication protein interacts with the retinoblastoma protein through a novel domain to determine symptoms and tissue specificity of infection in plants

    PubMed Central

    Kong, Ling-Jie; Orozco, Beverly M.; Roe, Judith L.; Nagar, Steve; Ou, Sharon; Feiler, Heidi S.; Durfee, Tim; Miller, Ann B.; Gruissem, Wilhelm; Robertson, Dominique; Hanley-Bowdoin, Linda

    2000-01-01

    Geminiviruses replicate in nuclei of mature plant cells after inducing the accumulation of host DNA replication machinery. Earlier studies showed that the viral replication factor, AL1, is sufficient for host induction and interacts with the cell cycle regulator, retinoblastoma (pRb). Unlike other DNA virus proteins, AL1 does not contain the pRb binding consensus, LXCXE, and interacts with plant pRb homo logues (pRBR) through a novel amino acid sequence. We mapped the pRBR binding domain of AL1 between amino acids 101 and 180 and identified two mutants that are differentially impacted for AL1–pRBR interactions. Plants infected with the E-N140 mutant, which is wild-type for pRBR binding, developed wild-type symptoms and accumulated viral DNA and AL1 protein in epidermal, mesophyll and vascular cells of mature leaves. Plants inoculated with the KEE146 mutant, which retains 16% pRBR binding activity, only developed chlorosis along the veins, and viral DNA, AL1 protein and the host DNA synthesis factor, proliferating cell nuclear antigen, were localized to vascular tissue. These results established the importance of AL1–pRBR interactions during geminivirus infection of plants. PMID:10880461

  12. Salt-Induced Expression of the Vacuolar H+-ATPase in the Common Ice Plant Is Developmentally Controlled and Tissue Specific1

    PubMed Central

    Golldack, Dortje; Dietz, Karl-Josef

    2001-01-01

    For salinity stress tolerance in plants, the vacuolar type H+-ATPase (V-ATPase) is of prime importance in energizing sodium sequestration into the central vacuole and it is known to respond to salt stress with increased expression and enzyme activity. In this work we provide information that the expressional response to salinity of the V-ATPase is regulated tissue and cell specifically under developmental control in the facultative halophyte common ice plant (Mesembryanthemum crystallinum). By transcript analysis of subunit E of the V-ATPase, amounts did not change in response to salinity stress in juvenile plants that are not salt-tolerant. In a converse manner, in halotolerant mature plants the transcript levels increased in leaves, but not in roots when salt stressed for 72 h. By in situ hybridizations and immunocytological protein analysis, subunit E was shown to be synthesized in all cell types. During salt stress, signal intensity declined in root cortex cells and in the cells of the root vascular cylinder. In salt-stressed leaves of mature plants, the strongest signals were localized surrounding the vasculature. Within control cells and with highest abundance in mesophyll cells of salt-treated leaves, accumulation of subunit E protein was observed in the cytoplasm, indicating its presence not only in the tonoplast, but also in other endoplasmic compartments. PMID:11299346

  13. 4-Phenylaminomethyl-Benzeneboric Acid Modified Tip Extraction for Determination of Brassinosteroids in Plant Tissues by Stable Isotope Labeling-Liquid Chromatography-Mass Spectrometry.

    PubMed

    Yu, Lei; Ding, Jun; Wang, Ya-Lan; Liu, Ping; Feng, Yu-Qi

    2016-01-19

    Monitoring brassinosteroids (BRs) has been of major interest of researchers as these substances play a crucial role in a variety of phytological processes in plants. However, the determination of endogenous BRs in plant tissue is still a challenging task due to their low abundance and the complex matrix of plant tissues. In this study, a single step strategy by combining tip extraction and in situ derivatization was proposed for BR analysis. In the proposed strategy, a mixed mode sorbent (C8-SO3H) in tip was modified with 4-phenylaminomethyl-benzeneboric acid (4-PAMBA) through cation exchange and hydrophobic interactions, and then used as a boronate affinity media to selectively capture and purify BRs from plant extract through the reaction of boric acid groups of 4-PAMBA and cis-diol on BRs. The BRs-4-PAMBA derivatives formed were easily eluted from the C8-SO3H tip by nullifying the ion exchange and hydrophobic interactions using ammonia acetonitrile, followed by LC-MS/MS analysis. BR standards, isotopically labeled with d5-4-phenylaminomethyl-benzeneboric acid (4-PAMBA-d5) were introduced to improve the assay precision of LC-MS/MS. Under the optimized conditions, the overall process could be completed within 1 h, which is greatly improved in speed compared with previously reported protocols. In addition, the detection sensitivities of labeled BRs were improved by over 2000-fold compared with unlabeled BRs, thus the consumption of plant materials was reduced to 50 mg. Finally, the proposed method was applied for the investigation of BRs response in rice toward Cd stress. PMID:26650986

  14. Spatial Distribution of Aboveground Carbon Stock of the Arboreal Vegetation in Brazilian Biomes of Savanna, Atlantic Forest and Semi-Arid Woodland.

    PubMed

    Scolforo, Henrique Ferraco; Scolforo, Jose Roberto Soares; Mello, Carlos Rogerio; Mello, Jose Marcio; Ferraz Filho, Antonio Carlos

    2015-01-01

    The objective of this study was to map the spatial distribution of aboveground carbon stock (using Regression-kriging) of arboreal plants in the Atlantic Forest, Semi-arid woodland, and Savanna Biomes in Minas Gerais State, southeastern Brazil. The database used in this study was obtained from 163 forest fragments, totaling 4,146 plots of 1,000 m2 distributed in these Biomes. A geographical model for carbon stock estimation was parameterized as a function of Biome, latitude and altitude. This model was applied over the samples and the residuals generated were mapped based on geostatistical procedures, selecting the exponential semivariogram theoretical model for conducting ordinary Kriging. The aboveground carbon stock was found to have a greater concentration in the north of the State, where the largest contingent of native vegetation is located, mainly the Savanna Biome, with Wooded Savanna and Shrub Savanna phytophysiognomes. The largest weighted averages of carbon stock per hectare were found in the south-center region (48.6 Mg/ha) and in the southern part of the eastern region (48.4 Mg/ha) of Minas Gerais State, due to the greatest predominance of Atlantic Forest Biome forest fragments. The smallest weighted averages per hectare were found in the central (21.2 Mg/ha), northern (20.4 Mg/ha), and northwestern (20.7 Mg/ha) regions of Minas Gerais State, where Savanna Biome fragments are predominant, in the phytophysiognomes Wooded Savanna and Shrub Savanna. PMID:26066508

  15. Spatial Distribution of Aboveground Carbon Stock of the Arboreal Vegetation in Brazilian Biomes of Savanna, Atlantic Forest and Semi-Arid Woodland

    PubMed Central

    2015-01-01

    The objective of this study was to map the spatial distribution of aboveground carbon stock (using Regression-kriging) of arboreal plants in the Atlantic Forest, Semi-arid woodland, and Savanna Biomes in Minas Gerais State, southeastern Brazil. The database used in this study was obtained from 163 forest fragments, totaling 4,146 plots of 1,000 m2 distributed in these Biomes. A geographical model for carbon stock estimation was parameterized as a function of Biome, latitude and altitude. This model was applied over the samples and the residuals generated were mapped based on geostatistical procedures, selecting the exponential semivariogram theoretical model for conducting ordinary Kriging. The aboveground carbon stock was found to have a greater concentration in the north of the State, where the largest contingent of native vegetation is located, mainly the Savanna Biome, with Wooded Savanna and Shrub Savanna phytophysiognomes. The largest weighted averages of carbon stock per hectare were found in the south-center region (48.6 Mg/ha) and in the southern part of the eastern region (48.4 Mg/ha) of Minas Gerais State, due to the greatest predominance of Atlantic Forest Biome forest fragments. The smallest weighted averages per hectare were found in the central (21.2 Mg/ha), northern (20.4 Mg/ha), and northwestern (20.7 Mg/ha) regions of Minas Gerais State, where Savanna Biome fragments are predominant, in the phytophysiognomes Wooded Savanna and Shrub Savanna. PMID:26066508

  16. Chemical composition and cell wall polysaccharide degradability of pith and rind tissues from mature maize internodes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was undertaken to identify tissue-specific biochemical traits that may be targeted in breeding programs for improving forage digestibility. We compared cell wall chemical composition and 24- and 96-h in vitro degradabilities in separated pith and rind tissues of the fourth above-ground in...

  17. The roles of community biomass and species pools in the regulation of plant diversity

    USGS Publications Warehouse

    Grace, J.B.

    2001-01-01

    Considerable debate has developed over the importance of community biomass and species pools in the regulation of community diversity. Attempts to explain patterns of plant diversity as a function of community biomass or productivity have been only partially successful and in general, have explained only a fraction of the observed variation in diversity. At the same time studies that have focused on the importance of species pools have led some to conclude that diversity is primarily regulated in the short term by the size of the species pool rather than by biotic interactions. In this paper, I explore how community biomass and species pools may work in combination to regulate diversity in herbaceous plant communities. To address this problem, I employ a simple model in which the dynamics of species richness are a function of aboveground community biomass and environmentally controlled gradients in species pools. Model results lead to two main predictions about the role of biomass regulation: (1) Seasonal dynamics of richness will tend to follow a regular oscillation, with richness rising to peak values during the early to middle portion of the growing season and then declining during the latter part of the season. (2.) Seasonal dieback of aboveground tissues facilitates the long-term maintenance of high levels of richness in the community. The persistence of aboveground tissues and accumulation of litter are especially important in limiting the number of species through the suppression of recruitment. Model results also lead to two main predictions about the role of species pools: (1) The height and position of peak richness relative to community biomass will be influenced by the rate at which the species pool increases as available soil resources increase. (2) Variations in nonresource environmental factors (e.g. soil pH or soil salinity) have the potential to regulate species pools in a way that is uncorrelated with aboveground biomass. Under extreme conditions

  18. Topographic Variation in Aboveground Biomass in a Subtropical Evergreen Broad-Leaved Forest in China

    PubMed Central

    Lin, Dunmei; Lai, Jiangshan; Muller-Landau, Helene C.; Mi, Xiangcheng; Ma, Keping

    2012-01-01

    The subtropical forest biome occupies about 25% of China, with species diversity only next to tropical forests. Despite the recognized importance of subtropical forest in regional carbon storage and cycling, uncertainties remain regarding the carbon storage of subtropical forests, and few studies have quantified within-site variation of biomass, making it difficult to evaluate the role of these forests in the global and regional carbon cycles. Using data for a 24-ha census plot in east China, we quantify aboveground biomass, characterize its spatial variation among different habitats, and analyse species relative contribution to the total aboveground biomass of different habitats. The average aboveground biomass was 223.0 Mg ha−1 (bootstrapped 95% confidence intervals [217.6, 228.5]) and varied substantially among four topographically defined habitats, from 180.6 Mg ha−1 (bootstrapped 95% CI [167.1, 195.0]) in the upper ridge to 245.9 Mg ha−1 (bootstrapped 95% CI [238.3, 253.8]) in the lower ridge, with upper and lower valley intermediate. In consistent with our expectation, individual species contributed differently to the total aboveground biomass of different habitats, reflecting significant species habitat associations. Different species show differently in habitat preference in terms of biomass contribution. These patterns may be the consequences of ecological strategies difference among different species. Results from this study enhance our ability to evaluate the role of subtropical forests in the regional carbon cycle and provide valuable information to guide the protection and management of subtropical broad-leaved forest for carbon sequestration and carbon storage. PMID:23118961

  19. Are Inventory Based and Remotely Sensed Above-Ground Biomass Estimates Consistent?

    PubMed Central

    Hill, Timothy C.; Williams, Mathew; Bloom, A. Anthony; Mitchard, Edward T. A.; Ryan, Casey M.

    2013-01-01

    Carbon emissions resulting from deforestation and forest degradation are poorly known at local, national and global scales. In part, this lack of knowledge results from uncertain above-ground biomass estimates. It is generally assumed that using more sophisticated methods of estimating above-ground biomass, which make use of remote sensing, will improve accuracy. We examine this assumption by calculating, and then comparing, above-ground biomass area density (AGBD) estimates from studies with differing levels of methodological sophistication. We consider estimates based on information from nine different studies at the scale of Africa, Mozambique and a 1160 km2 study area within Mozambique. The true AGBD is not known for these scales and so accuracy cannot be determined. Instead we consider the overall precision of estimates by grouping different studies. Since an the accuracy of an estimate cannot exceed its precision, this approach provides an upper limit on the overall accuracy of the group. This reveals poor precision at all scales, even between studies that are based on conceptually similar approaches. Mean AGBD estimates for Africa vary from 19.9 to 44.3 Mg ha−1, for Mozambique from 12.7 to 68.3 Mg ha−1, and for the 1160 km2 study area estimates range from 35.6 to 102.4 Mg ha−1. The original uncertainty estimates for each study, when available, are generally small in comparison with the differences between mean biomass estimates of different studies. We find that increasing methodological sophistication does not appear to result in improved precision of AGBD estimates, and moreover, inadequate estimates of uncertainty obscure any improvements in accuracy. Therefore, despite the clear advantages of remote sensing, there is a need to improve remotely sensed AGBD estimates if they are to provide accurate information on above-ground biomass. In particular, more robust and comprehensive uncertainty estimates are needed. PMID:24069275

  20. Characterization of S-waves Generated from Aboveground and Underground Explosions in Alluvium

    NASA Astrophysics Data System (ADS)

    Bonner, J. L.; Napoli, V.; Reinke, R.

    2014-12-01

    The source of S-waves from explosions is debated within the nuclear explosion monitoring community. The HUMBLE REDWOOD III (HRIII) experiment series in 2012 located in New Mexico provides a unique dataset to further our understanding of the generation of S-waves in alluvium by comparing and contrasting co-located aboveground and underground explosions. Two 91 kg explosions were detonated in alluvium at the same location, but HRIII-1 was detonated at 2 m aboveground and HRIII-2 was detonated at 7 m belowground and was fully coupled. A semicircular seismic network of 21 stations was deployed at 1 km to record the explosions. We determined that the belowground HRIII-2 explosion generated P-waves that were 2.4x larger than the aboveground HRIII-1 shot, thus we scaled the aboveground signals by this factor. Visual inspection of the waveforms after scaling showed similar P-wave, higher mode (HM) Rayleigh-wave, and fundamental mode Rayleigh-wave amplitudes for both shots on the vertical and radial components; however the largest differences were observed on the transverse components. Additional Love wave (or SH) energy is generated by the underground explosion that is not accounted for in the P-wave scaling factor. Spectral ratios confirm that the increased SH generation occurs at frequencies between 10-100 Hz. Future work includes modeling of these waveforms to explain the larger SH waves as well as analysis of S-wave generation from a similar set of above- and below-ground explosions in limestone.

  1. Are patterns in nutrient limitation belowground consistent with those aboveground: Results from a 4 million year chronosequence

    USGS Publications Warehouse

    Reed, S.C.; Vitousek, P.M.; Cleveland, C.C.

    2011-01-01

    Accurately predicting the effects of global change on net carbon (C) exchange between terrestrial ecosystems and the atmosphere requires a more complete understanding of how nutrient availability regulates both plant growth and heterotrophic soil respiration. Models of soil development suggest that the nature of nutrient limitation changes over the course of ecosystem development, transitioning from nitrogen (N) limitation in 'young' sites to phosphorus (P) limitation in 'old' sites. However, previous research has focused primarily on plant responses to added nutrients, and the applicability of nutrient limitation-soil development models to belowground processes has not been thoroughly investigated. Here, we assessed the effects of nutrients on soil C cycling in three different forests that occupy a 4 million year substrate age chronosequence where tree growth is N limited at the youngest site, co-limited by N and P at the intermediate-aged site, and P limited at the oldest site. Our goal was to use short-term laboratory soil C manipulations (using 14C-labeled substrates) and longer-term intact soil core incubations to compare belowground responses to fertilization with aboveground patterns. When nutrients were applied with labile C (sucrose), patterns of microbial nutrient limitation were similar to plant patterns: microbial activity was limited more by N than by P in the young site, and P was more limiting than N in the old site. However, in the absence of C additions, increased respiration of native soil organic matter only occurred with simultaneous additions of N and P. Taken together, these data suggest that altered nutrient inputs into ecosystems could have dissimilar effects on C cycling above- and belowground, that nutrients may differentially affect of the fate of different soil C pools, and that future changes to the net C balance of terrestrial ecosystems will be partially regulated by soil nutrient status. ?? 2010 US Government.

  2. Application of Tissue Culture in Ornamental Breeding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant tissue culture can be broadly defined as the culture of plant cells, tissues, or organs under sterile or aseptic conditions. To most growers, micropropagation is the term that perhaps best describes plant tissue culture. However, plant tissue culture plays an important role through its many ap...

  3. Dynamics of Aboveground Phytomass of the Circumpolar Arctic Tundra During the Past Three Decades

    NASA Technical Reports Server (NTRS)

    Epstein, Howard E.; Raynolds, Martha K.; Walker, Donald A.; Bhatt, Uma S.; Tucker, Compton J.; Pinzon, Jorge E.

    2012-01-01

    Numerous studies have evaluated the dynamics of Arctic tundra vegetation throughout the past few decades, using remotely sensed proxies of vegetation, such as the normalized difference vegetation index (NDVI). While extremely useful, these coarse-scale satellite-derived measurements give us minimal information with regard to how these changes are being expressed on the ground, in terms of tundra structure and function. In this analysis, we used a strong regression model between NDVI and aboveground tundra phytomass, developed from extensive field-harvested measurements of vegetation biomass, to estimate the biomass dynamics of the circumpolar Arctic tundra over the period of continuous satellite records (1982-2010). We found that the southernmost tundra subzones (C-E) dominate the increases in biomass, ranging from 20 to 26%, although there was a high degree of heterogeneity across regions, floristic provinces, and vegetation types. The estimated increase in carbon of the aboveground live vegetation of 0.40 Pg C over the past three decades is substantial, although quite small relative to anthropogenic C emissions. However, a 19.8% average increase in aboveground biomass has major implications for nearly all aspects of tundra ecosystems including hydrology, active layer depths, permafrost regimes, wildlife and human use of Arctic landscapes. While spatially extensive on-the-ground measurements of tundra biomass were conducted in the development of this analysis, validation is still impossible without more repeated, long-term monitoring of Arctic tundra biomass in the field.

  4. Allometric Equations for Aboveground and Belowground Biomass Estimations in an Evergreen Forest in Vietnam

    PubMed Central

    Nam, Vu Thanh; van Kuijk, Marijke; Anten, Niels P. R.

    2016-01-01

    Allometric regression models are widely used to estimate tropical forest biomass, but balancing model accuracy with efficiency of implementation remains a major challenge. In addition, while numerous models exist for aboveground mass, very few exist for roots. We developed allometric equations for aboveground biomass (AGB) and root biomass (RB) based on 300 (of 45 species) and 40 (of 25 species) sample trees respectively, in an evergreen forest in Vietnam. The biomass estimations from these local models were compared to regional and pan-tropical models. For AGB we also compared local models that distinguish functional types to an aggregated model, to assess the degree of specificity needed in local models. Besides diameter at breast height (DBH) and tree height (H), wood density (WD) was found to be an important parameter in AGB models. Existing pan-tropical models resulted in up to 27% higher estimates of AGB, and overestimated RB by nearly 150%, indicating the greater accuracy of local models at the plot level. Our functional group aggregated local model which combined data for all species, was as accurate in estimating AGB as functional type specific models, indicating that a local aggregated model is the best choice for predicting plot level AGB in tropical forests. Finally our study presents the first allometric biomass models for aboveground and root biomass in forests in Vietnam. PMID:27309718

  5. Improving Aboveground Carbon Estimates in Dryland Ecosystems with Airborne LiDAR and Satellite Laser Altimetry

    NASA Astrophysics Data System (ADS)

    Glenn, N. F.; Shrestha, R.; Li, A.; Spaete, L.

    2014-12-01

    Numerous studies have demonstrated the utility of ground and airborne LiDAR data to quantify ecosystem structure. In addition, data from satellite-based laser altimetry (e.g. ICESat's GLAS instrument) have been used to estimate vegetation heights, aboveground carbon, and topography in forested areas. With the upcoming ICESAT-2 satellite scheduled to launch in 2017, we have the potential to map vegetation characteristics and dynamics in other ecosystems, including semiarid and low-height ecosystems, at global and regional scales. The ICESat-2 satellite will include the Advanced Topographic Laser Altimeter System (ATLAS) with a configuration of 6 laser beams with 532 nm wavelength and photon counting detectors. We will demonstrate the potential of ICESat-2 to provide estimates of vegetation structure and topography in a dryland ecosystem by simulating the configuration of the ATLAS mission. We will also examine how airborne LiDAR can be used together with ICESat-2 and other satellite data to achieve estimates of aboveground carbon. We will explore how these data may be used for future monitoring and quantification of spatial and temporal changes in aboveground carbon and topography.

  6. Allometric Equations for Aboveground and Belowground Biomass Estimations in an Evergreen Forest in Vietnam.

    PubMed

    Nam, Vu Thanh; van Kuijk, Marijke; Anten, Niels P R

    2016-01-01

    Allometric regression models are widely used to estimate tropical forest biomass, but balancing model accuracy with efficiency of implementation remains a major challenge. In addition, while numerous models exist for aboveground mass, very few exist for roots. We developed allometric equations for aboveground biomass (AGB) and root biomass (RB) based on 300 (of 45 species) and 40 (of 25 species) sample trees respectively, in an evergreen forest in Vietnam. The biomass estimations from these local models were compared to regional and pan-tropical models. For AGB we also compared local models that distinguish functional types to an aggregated model, to assess the degree of specificity needed in local models. Besides diameter at breast height (DBH) and tree height (H), wood density (WD) was found to be an important parameter in AGB models. Existing pan-tropical models resulted in up to 27% higher estimates of AGB, and overestimated RB by nearly 150%, indicating the greater accuracy of local models at the plot level. Our functional group aggregated local model which combined data for all species, was as accurate in estimating AGB as functional type specific models, indicating that a local aggregated model is the best choice for predicting plot level AGB in tropical forests. Finally our study presents the first allometric biomass models for aboveground and root biomass in forests in Vietnam. PMID:27309718

  7. Above-ground biomass estimation of tuberous bulrush ( Bolboschoenus planiculmis) in mudflats using remotely sensed multispectral image

    NASA Astrophysics Data System (ADS)

    Kim, Ji Yoon; Im, Ran-Young; Do, Yuno; Kim, Gu-Yeon; Joo, Gea-Jae

    2016-03-01

    We present a multivariate regression approach for mapping the spatial distribution of above-ground biomass (AGB) of B. planiculmis using field data and coincident moderate spatial resolution satellite imagery. A total of 232 ground sample plots were used to estimate the biomass distribution in the Nakdong River estuary. Field data were overlain and correlated with digital values from an atmospherically corrected multispectral image (Landsat 8). The AGB distribution was derived using empirical models trained with field-measured AGB data. The final regression model for AGB estimation was composed using the OLI3, OLI4, and OLI7 spectral bands. The Pearson correlation between the observed and predicted biomass was significant (R = 0.84, p < 0.0001). OLI3 made the largest contribution to the final model (relative coefficient value: 53.4%) and revealed a negative relationship with the AGB biomass. The total distribution area of B. planiculmis was 1,922,979 m2. Based on the model estimation, the total AGB had a dry weight (DW) of approximately 298.2 tons. The distribution of high biomass stands (> 200 kg DW/900 m2) constituted approximately 23.91% of the total vegetated area. Our findings suggest the expandability of remotely sensed products to understand the distribution pattern of estuarine plant productivity at the landscape level.

  8. Potential for post-closure radionuclide redistribution due to biotic intrusion: aboveground biomass, litter production rates, and the distribution of root mass with depth at material disposal area G, Los Alamos National Laboratory

    SciTech Connect

    French, Sean B; Christensen, Candace; Jennings, Terry L; Jaros, Christopher L; Wykoff, David S; Crowell, Kelly J; Shuman, Rob

    2008-01-01

    Low-level radioactive waste (LLW) generated at the Los Alamos National Laboratories (LANL) is dispose