Induction of murine embryonic stem cell differentiation by medicinal plant extracts.

Science.gov (United States)

Reynertson, Kurt A; Charlson, Mary E; Gudas, Lorraine J

2011-01-01

Epidemiological evidence indicates that diets high in fruits and vegetables provide a measure of cancer chemoprevention due to phytochemical constituents. Natural products are a rich source of cancer chemotherapy drugs, and primarily target rapidly cycling tumor cells. Increasing evidence indicates that many cancers contain small populations of resistant, stem-like cells that have the capacity to regenerate tumors following chemotherapy and radiation, and have been linked to the initiation of metastases. Our goal is to discover natural product-based clinical or dietary interventions that selectively target cancer stem cells, inducing differentiation. We adapted an alkaline phosphatase (AP) stain to assay plant extracts for the capacity to induce differentiation in embryonic stem (ES) cells. AP is a characteristic marker of undifferentiated ES cells, and this represents a novel approach to screening medicinal plant extracts. Following a survey of approximately 100 fractions obtained from 12 species of ethnomedically utilized plants, we found fractions from 3 species that induced differentiation, decreasing AP and transcript levels of pluripotency markers (Nanog, Oct-4, Rex-1). These fractions affected proliferation of murine ES, and human embryonal, prostate, and breast carcinoma cells in a dose-dependent manner. Several phytochemical constituents were isolated; the antioxidant phytochemicals ellagic acid and gallic acid were shown to affect viability of cultured breast carcinoma cells. Copyright © 2010 Elsevier Inc. All rights reserved.

Evaluation of alternative planting strategies to reduce wheat stem sawfly (Hymenoptera: Cephidae) damage to spring wheat in the northern Great Plains.

Science.gov (United States)

Beres, B L; Cárcamo, H A; Bremer, E

2009-12-01

Wheat, Triticum aestivum L., producers are often reluctant to use solid-stemmed wheat cultivars resistant to wheat stem sawfly, Cephus cinctus Norton (Hymenoptera: Cephidae), due to concerns regarding yield, efficacy or market opportunities. We evaluated the impact of several planting strategies on wheat yield and quality and wheat stem sawfly infestation at two locations over a three-year period. Experimental units consisted of large plots (50 by 200 m) located on commercial farms adjacent to wheat stem sawfly-infested fields. Compared with a monoculture of a hollow-stemmed cultivar ('AC Barrie'), planting a monoculture of a solid-stemmed cultivar ('AC Eatonia') increased yield by an average of 16% (0.4 mg ha(-1)) and increased the grade of wheat by one unit at the two most heavily infested site-years. Planting a 1:1 blend of AC Eatonia and AC Barrie increased yield by an average of 11%, whereas planting 20- or 40-m plot margins to AC Eatonia increased yield by an average of 8%. High wheat stem sawfly pressure limited the effectiveness of using resistant cultivars in field margins because plants were often infested beyond the plot margin, with uniform infestation down the length of the plots at the two most heavily infested site-years. The effectiveness of AC Eatonia to reduce wheat stem sawfly survivorship was modest in this study, probably due to weather-related factors influencing pith expression and to the high abundance of wheat stem sawfly. Greater benefits from planting field margins to resistant cultivars or planting a blend of resistant and susceptible cultivars might be achievable under lower wheat stem sawfly pressure.

A Multiple Decrement Life Table Reveals That Host Plant Resistance and Parasitism Are Major Causes of Mortality for the Wheat Stem Sawfly.

Science.gov (United States)

Buteler, Micaela; Peterson, Robert K D; Hofland, Megan L; Weaver, David K

2015-12-01

This study investigated the dynamics of parasitism, host plant resistance, pathogens, and predation on the demography of wheat stem sawfly, Cephus cinctus Norton (Hymenoptera: Cephidae), developing in susceptible (hollow stem) and resistant (solid stem) wheat hosts. This study is also the first to investigate the prevalence and impact of cannibalism on wheat stem sawfly mortality. Wheat stem sawflies were sampled in two commercial wheat fields over 4 yr from the egg stage through adult emergence, and multiple decrement life tables were constructed and analyzed. Cannibalism, host plant resistance, or unknown factors were the most prevalent factors causing egg mortality. Summer mortality of prediapause larvae ranged from 28 to 84%, mainly due to parasitism by Bracon cephi (Gahan) and Bracon lissogaster Muesebeck, cannibalism, and host plant resistance. Winter mortality ranged from 6 to 54% of the overwintering larvae, mainly due to unknown factors or pathogens. Cannibalism is a major cause of irreplaceable mortality because it is absolute, with only a single survivor in every multiple infested stem. Subsequent to obligate cannibalism, mortality of feeding larvae due to host plant resistance was lower in hollow stem wheat than in solid stem wheat. Mortality from host plant resistance was largely irreplaceable. Irreplaceable mortality due to parasitoids was greater in hollow stem wheat than in solid stem wheat. Host plant resistance due to stem solidness and parasitism in hollow stems cause substantial mortality in populations of actively feeding larvae responsible for all crop losses. Therefore, enhancing these mortality factors is vital to effective integrated pest management of wheat stem sawfly. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Effects of Different Planting Times of Different Rice Cultivars on Control of the Striped Stem Borer (Chilo suppressalis (Lepidoptera: Pyralidae

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T. Oskou

2016-06-01

Full Text Available Introduction: Rice (Oryza sativa L. is one of the world’s most important staple food crops. In Asia, it is the main item of the diet of 3.5 billion people. Rice stem borers are common insect pests in many rice growing countries. Striped stem borer (Chilo suppressalis Walker, belonging to Lepidoptera and family of Pyralidae is the most important rice pest in the Northern Iran. Stem borer larva damages rice stem and disturbs nutrient translocation from root to leaf. As the result, tillers in vegetative stage died, which is called dead heart. When larva infests generative stage, it causes empty panicle, which is called white head. Integrated pest management (IPM practices for controlling the stem borers in Iran have not been fully implemented because of limited control technologies which are available. Farmers often rely on heavily insecticide application, although many insecticide applications are not effective. Therefore, many physical and cultural practices have been suggested, including adjustment of planting time to escape the plant from heavy pest. Materials and Methods: The study was conducted in deputy of rice research institute in Amol, Mazandaran, Iran, during 2011-2012. The experiment was arranged in split plot design with planting time as main plot and cultivar as subplot and was replicated three times. Three planting times tested were the first planting time i.e. 15 days before farmers’ planting time, the second planting time (simultaneously with farmers’ planting time, and the third planting time (15days after farmers’ planting time. Six rice cultivars tested, representing three types of rice cultivar, Tarom and Kohsar (early maturity cultivars, Shirodi and Fajr (medium maturity cultivars, Neda and Nemat (late maturity cultivar. Rice seedlings were transplanted at 25 cm planting distance in a 3 m x 9 m plot size. Weeding and fertilization were done as recommended. No insecticide was applied. Dead hearts and white heads were

Comparison of Stevia plants grown from seeds, cuttings and stem-tip cultures for growth and sweet diterpene glucosides.

Science.gov (United States)

Tamura, Y; Nakamura, S; Fukui, H; Tabata, M

1984-10-01

The growth and sweet diterpene glucosides of Stevia plants propagated by stem-tip cultures were compared with those of the control plants propagated by seeds. There was no significant difference between the two groups both in growth and in chemical composition. As for the contents of sweet diterpene glucosides, however, the clonal plants showed significantly smaller variations than the sexually propagated plants; they were almost as homogeneous as the plants propagated by cuttings. These results suggest that the clonal propagation by stem-tip culture is an effective method of obtaining a population of uniform plants for the production of sweet diterpene glucosides.

Using laser to measure stem thickness and cut weed stems

DEFF Research Database (Denmark)

Heisel, T.; Schou, Jørgen; Andreasen, C.

2002-01-01

Stem thickness of the weed Solanum nigrum and the crop sugarbeet was determined with a He-Ne laser using a novel non-destructive technique measuring stem shadow. Thereafter, the stems were cut close to the soil surface with a CO2 laser. Treatments were carried out on pot plants, grown....... A binary model was also tested. The non-linear model incorporating stem thickness described the data best, indicating that it would be possible to optimize laser cutting by measuring stem thickness before cutting. The general tendency was that more energy was needed the thicker the stem. Energy uses...... in the greenhouse, at two different growth stages, and plant dry matter was measured 2-5 weeks after treatment. The relationship between plant dry weight and laser energy was analysed using two different non-linear dose-response regression models; one model included stem thickness as a variable, the other did not...

Potential biosorbent, Haloxylon recurvum plant stems, for the removal of methylene blue dye

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Warda Hassan

2017-05-01

Full Text Available Conventional technologies for the removal of dyes from the waste water are proving expensive due to non-regenerable materials used and their high costs. The use of dried biomass from Haloxylon recurvum plant stems (HRS was studied for the removal of methylene blue, a textile dye, from its aqueous solution. FTIR studies revealed a variety of functional groups on the plant surface including carboxyl and amino groups. The pH at the point of zero charge (pHpzc was found to be 6.3. The dye uptake by the plant increased with increasing pH, time of contact and dye concentration. Lagergren Pseudo first order and the Ho’s pseudo second order models were used to study the kinetics. The Langmuir and Freundlich equilibrium models were studied and the qmax was 22.93 mg/g. The changes in the values of free energy (ΔGo and enthalpy (ΔHo indicated the spontaneous, feasible and exothermic nature of the sorption process. H. recurvum plant is locally available in large quantities, so the powdered stems can act as a cost-effective and ecofriendly biosorbent for the removal of the dye from its aqueous solutions.

Involvement of plant stem cells or stem cell-like cells in dedifferentiation

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Fangwei eJiang

2015-11-01

Full Text Available Dedifferentiation is the transformation of cells from a given differentiated state to a less differentiated or stem cell-like state. Stem cell-related genes play important roles in dedifferentiation, which exhibits similar histone modification and DNA methylation features to stem cell maintenance. Hence, stem cell-related factors possibly synergistically function to provide a specific niche beneficial to dedifferentiation. During callus formation in Arabidopsis petioles, cells adjacent to procambium cells (stem cell-like cells are dedifferentiated and survive more easily than other cell types. This finding indicates that stem cells or stem cell-like cells may influence the dedifferentiating niche. In this paper, we provide a brief overview of stem cell maintenance and dedifferentiation regulation. We also summarize current knowledge of genetic and epigenetic mechanisms underlying the balance between differentiation and dedifferentiation. Furthermore, we discuss the correlation of stem cells or stem cell-like cells with dedifferentiation.

Estimating 3D Leaf and Stem Shape of Nursery Paprika Plants by a Novel Multi-Camera Photography System

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Yu Zhang

2016-06-01

Full Text Available For plant breeding and growth monitoring, accurate measurements of plant structure parameters are very crucial. We have, therefore, developed a high efficiency Multi-Camera Photography (MCP system combining Multi-View Stereovision (MVS with the Structure from Motion (SfM algorithm. In this paper, we measured six variables of nursery paprika plants and investigated the accuracy of 3D models reconstructed from photos taken by four lens types at four different positions. The results demonstrated that error between the estimated and measured values was small, and the root-mean-square errors (RMSE for leaf width/length and stem height/diameter were 1.65 mm (R2 = 0.98 and 0.57 mm (R2 = 0.99, respectively. The accuracies of the 3D model reconstruction of leaf and stem by a 28-mm lens at the first and third camera positions were the highest, and the number of reconstructed fine-scale 3D model shape surfaces of leaf and stem is the most. The results confirmed the practicability of our new method for the reconstruction of fine-scale plant model and accurate estimation of the plant parameters. They also displayed that our system is a good system for capturing high-resolution 3D images of nursery plants with high efficiency.

Estimating 3D Leaf and Stem Shape of Nursery Paprika Plants by a Novel Multi-Camera Photography System

Science.gov (United States)

Zhang, Yu; Teng, Poching; Shimizu, Yo; Hosoi, Fumiki; Omasa, Kenji

2016-01-01

For plant breeding and growth monitoring, accurate measurements of plant structure parameters are very crucial. We have, therefore, developed a high efficiency Multi-Camera Photography (MCP) system combining Multi-View Stereovision (MVS) with the Structure from Motion (SfM) algorithm. In this paper, we measured six variables of nursery paprika plants and investigated the accuracy of 3D models reconstructed from photos taken by four lens types at four different positions. The results demonstrated that error between the estimated and measured values was small, and the root-mean-square errors (RMSE) for leaf width/length and stem height/diameter were 1.65 mm (R2 = 0.98) and 0.57 mm (R2 = 0.99), respectively. The accuracies of the 3D model reconstruction of leaf and stem by a 28-mm lens at the first and third camera positions were the highest, and the number of reconstructed fine-scale 3D model shape surfaces of leaf and stem is the most. The results confirmed the practicability of our new method for the reconstruction of fine-scale plant model and accurate estimation of the plant parameters. They also displayed that our system is a good system for capturing high-resolution 3D images of nursery plants with high efficiency. PMID:27314348

Analysis of Metabolites in Stem Parasitic Plant Interactions: Interaction of Cuscuta–Momordica versus Cassytha–Ipomoea

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Furuhashi, Takeshi; Nakamura, Takemichi; Iwase, Koji

2016-01-01

Cuscuta and Cassytha are two well-known stem parasitic plant genera with reduced leaves and roots, inducing haustoria in their stems. Their similar appearance in the field has been recognized, but few comparative studies on their respective plant interactions are available. To compare their interactions, we conducted a metabolite analysis of both the Cassytha–Ipomoea and the Cuscuta–Momordica interaction. We investigated the energy charge of the metabolites by UFLC (ultra-high performance liquid chromatography), and conducted GC-MS (gas chromatography-mass spectrometry) analysis for polar metabolites (e.g., saccharides, polyols) and steroids. The energy charge after parasitization changed considerably in Cassytha but not in Cusucta. Cuscuta changed its steroid pattern during the plant interaction, whereas Cassytha did not. In the polar metabolite analysis, the laminaribiose increase after parasitization was conspicuous in Cuscuta, but not in Cassytha. This metabolite profile difference points to different lifestyles and parasitic strategies. PMID:27941603

Analysis of Metabolites in Stem Parasitic Plant Interactions: Interaction of Cuscuta–Momordica versus Cassytha–Ipomoea

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Takeshi Furuhashi

2016-12-01

Full Text Available Cuscuta and Cassytha are two well-known stem parasitic plant genera with reduced leaves and roots, inducing haustoria in their stems. Their similar appearance in the field has been recognized, but few comparative studies on their respective plant interactions are available. To compare their interactions, we conducted a metabolite analysis of both the Cassytha–Ipomoea and the Cuscuta–Momordica interaction. We investigated the energy charge of the metabolites by UFLC (ultra-high performance liquid chromatography, and conducted GC-MS (gas chromatography-mass spectrometry analysis for polar metabolites (e.g., saccharides, polyols and steroids. The energy charge after parasitization changed considerably in Cassytha but not in Cusucta. Cuscuta changed its steroid pattern during the plant interaction, whereas Cassytha did not. In the polar metabolite analysis, the laminaribiose increase after parasitization was conspicuous in Cuscuta, but not in Cassytha. This metabolite profile difference points to different lifestyles and parasitic strategies.

Analysis of Metabolites in Stem Parasitic Plant Interactions: Interaction of Cuscuta-Momordica versus Cassytha-Ipomoea.

Science.gov (United States)

Furuhashi, Takeshi; Nakamura, Takemichi; Iwase, Koji

2016-12-07

Cuscuta and Cassytha are two well-known stem parasitic plant genera with reduced leaves and roots, inducing haustoria in their stems. Their similar appearance in the field has been recognized, but few comparative studies on their respective plant interactions are available. To compare their interactions, we conducted a metabolite analysis of both the Cassytha-Ipomoea and the Cuscuta-Momordica interaction. We investigated the energy charge of the metabolites by UFLC (ultra-high performance liquid chromatography), and conducted GC-MS (gas chromatography-mass spectrometry) analysis for polar metabolites (e.g., saccharides, polyols) and steroids. The energy charge after parasitization changed considerably in Cassytha but not in Cusucta . Cuscuta changed its steroid pattern during the plant interaction, whereas Cassytha did not. In the polar metabolite analysis, the laminaribiose increase after parasitization was conspicuous in Cuscuta , but not in Cassytha . This metabolite profile difference points to different lifestyles and parasitic strategies.

Solid-stemmed spring wheat cultivars give better androgenic response than hollow-stemmed cultivars in anther culture.

Science.gov (United States)

Weigt, Dorota; Kiel, Angelika; Nawracała, Jerzy; Pluta, Mateusz; Łacka, Agnieszka

2016-01-01

Solid-stemmed spring wheat cultivars ( Triticum aestivum L.) are resistant to the stem sawfly ( Cephus cinctus Nort.) and lodging. Anthers of 24 spring wheat cultivars with varying content of pith in the stem were used in the experiment. All were classified into three groups: solid, medium-solid and hollow stems. There was considerable influence of the cultivar on callus formation and green plant regeneration. The highest efficiency of green plant regeneration (24%) was observed for the solid-stemmed AC Abbey cultivar. There was no regeneration from the explants of four cultivars: CLTR 7027, Alentejano, Marquis and Bombona. Principal component analysis showed no differences between the cases under observation (callus induction and green plant regeneration) in their response to pre-treatment temperatures (4 and 8°C). The examination of the effects of various auxin types in the induction medium on callus formation and green plant regeneration revealed that the strongest stimulation of these processes was observed in the C17 medium with 2,4-D and dicamba. The efficiency of callus formation and green plant regeneration was greater in solid-stemmed cultivars than in hollow-stemmed cultivars.

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

Science.gov (United States)

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…

Use of stem sliced from in vitro plants of papaya (hybrid IBP 42-99 by obtained callus with embryogenic structure

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Jorge Gallardo Colina

2004-10-01

Full Text Available Inside in vitro propagation via, the somatic embriogenesis offers possibilities of obtaining top volumes of production in a minor period of time and a lower cost, which are a method potentially more efficient than the regeneration via organogenesis. In papaya the somatic embryogenesis could have developed from zigotic embryos and axis hipocotilos, nevertheless in case of the hybrids these methods cannot be used and it becomes necessary to develop it from a somatic fabric, without link with the sexual reproduction. This work chased as main objective Evaluated the use of in vitro plants stem sections of the Carica papaya IBP 42-99 hybrid for the formation of callus with embryogenic structures. As plant material were use in vitro plants of the papaya hybrid IBP 42-99. For it there took sections of different parts of the stem from the meristem up to the base of the in vitro plants, was use the culture medium Nitsh and Nitsh supplemented with 1.5 mg.l-1 of 6-BAP and 1.5 mg.l-1 of AIA. It was achieved to obtain callus from the stem sections with the culture medium used, nevertheless, in the treatments where used cylinders inside 1.0 cm from the apex down, the best results were achieved. The use of in vitro plants stem sections as explant for the formation of callus in this vegetable species it opens new possibilities for his in vitro propagation, specially in case of resultant hybrids of genetic improvement programs. Key words: apexes, Carica papaya, callogenesis, somatic embryogenesis

Solid-stemmed spring wheat cultivars give better androgenic response than hollow-stemmed cultivars in anther culture

OpenAIRE

Weigt, Dorota; Kiel, Angelika; Nawraca?a, Jerzy; Pluta, Mateusz; ?acka, Agnieszka

2016-01-01

Solid-stemmed spring wheat cultivars (Triticum aestivum L.) are resistant to the stem sawfly (Cephus cinctus Nort.) and lodging. Anthers of 24 spring wheat cultivars with varying content of pith in the stem were used in the experiment. All were classified into three groups: solid, medium?solid and hollow stems. There was considerable influence of the cultivar on callus formation and green plant regeneration. The highest efficiency of green plant regeneration (24%) was observed for the solid-s...

Enhancement of organ regeneration in animal models by a stem cell-stimulating plant mixture.

Science.gov (United States)

Kiss, István; Tibold, Antal; Halmosi, Róbert; Bartha, Eva; Koltai, Katalin; Orsós, Zsuzsanna; Bujdosó, László; Ember, István

2010-06-01

Adult stem cells play an important role in the regeneration of damaged organs. Attempts have already been made to enhance stem cell production by cytokines, in order to increase the improvement of cardiac functions after myocardial infarction. In our present study we investigated the possibility whether instead of cytokine injection dietary stimulation of stem cell production accelerates the organ regeneration in animals. A dietary supplement, Olimpiq StemXCell (Crystal Institute Ltd., Eger, Hungary), containing plant extracts (previously proved to increase the number of circulating CD34(+) cells) was consumed in human equivalent doses by the experimental animals. In the first experiment carbon tetrachloride was applied to CBA/Ca mice, to induce liver damage, and liver weights between StemXCell-fed and control animals were compared 10 days after the treatment. In the second model experimental diabetes was induced in F344 rats by alloxan. Blood sugar levels were measured for 5 weeks in the control and StemXCell-fed groups. The third part of the study investigated the effect of StemXCell on cardiac functions. Eight weeks after causing a myocardial infarction in Wistar rats by isoproterenol, left ventricular ejection fraction was determined as a functional parameter of myocardial regeneration. In all three animal models StemXCell consumption statistically significantly improved the organ regeneration (relative liver weights, 4.78 +/-0.06 g/100 g vs. 4.97 +/- 0.07 g/100 g; blood sugar levels at week 5, 16 +/- 1.30 mmol/L vs. 10.2 +/- 0.92 mmol/L; ejection fraction, 57.5 +/- 2.23 vs. 68.2 +/- 4.94; controls vs. treated animals, respectively). Our study confirms the hypothesis that dietary enhancement of stem cell production may protect against organ injuries and helps in the regeneration.

A plant economics spectrum in Mediterranean forests along environmental gradients: is there coordination among leaf, stem and root traits?

NARCIS (Netherlands)

Riva, de la E.G.; Tosto, A.; Perez-Ramos, I.M.; Navarro-Fernandez, C.M.; Olmos, M.; Anten, N.P.R.; Maranon, T.; Villar, R.

2016-01-01

Questions: Is there any evidence of coordination among leaf, stem and root traits, and thereby of the existence of a plant economics spectrum at the species and community level in Mediterranean forests? Are these traits related to plant size and seedmass? Location: Mediterranean forests and

Stem nematode counteracts plant resistance of aphids in alfalfa, Medicago sativa.

Science.gov (United States)

Ramirez, Ricardo A; Spears, Lori R

2014-10-01

Plants are exploited by a diverse community of insect herbivores and phytopathogens that interact indirectly through plant-mediated interactions. Generally, plants are thought to respond to insects and pathogens through different defensive signaling pathways. As plants are selected for resistance to one phytophagous organism type (insect vs. pathogen) in managed systems, it is not clear how this selection may affect community interactions. This study examined the effect of nematode-resistant varieties on aphid (Acyrthosiphon pisum) suppression, and then determined how infection by the stem nematode, Ditylenchus dipsaci, mediated ecological effects on aphids and on plant defense proteins. Four alfalfa (Medicago sativa) varieties were selected with resistance to nematodes only (+,-), aphids only (-,+), nematodes and aphids (+,+), and susceptibility to nematodes and aphids (-,-). Field and greenhouse experiments were conducted to isolate the effect of nematode infection and aphid abundance on each variety. We found that varieties resistant to nematode, regardless of aphid resistance, had the lowest aphid counts, suggesting possible cross-resistance. Aphid abundance, however, increased when plants were exposed to nematodes. Resistant varieties were associated with elevated saponins but these compounds were not affected by insect or pathogen feeding. Concentrations of peroxidases and trypsin inhibitors, however, were increased in nematode resistant varieties when exposed to nematodes and aphids, respectively. The patterns of plant defense were variable, and a combination of resistance traits and changes in nutrient availability may drive positive interactions between nematodes and aphids aboveground.

Genomic Selection for Quantitative Adult Plant Stem Rust Resistance in Wheat

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Jessica E. Rutkoski

2014-11-01

Full Text Available Quantitative adult plant resistance (APR to stem rust ( f. sp. is an important breeding target in wheat ( L. and a potential target for genomic selection (GS. To evaluate the relative importance of known APR loci in applying GS, we characterized a set of CIMMYT germplasm at important APR loci and on a genome-wide profile using genotyping-by-sequencing (GBS. Using this germplasm, we describe the genetic architecture and evaluate prediction models for APR using data from the international Ug99 stem rust screening nurseries. Prediction models incorporating markers linked to important APR loci and seedling phenotype scores as fixed effects were evaluated along with the classic prediction models: Multiple linear regression (MLR, Genomic best linear unbiased prediction (G-BLUP, Bayesian Lasso (BL, and Bayes Cπ (BCπ. We found the region to play an important role in APR in this germplasm. A model using linked markers as fixed effects in G-BLUP was more accurate than MLR with linked markers (-value = 0.12, and ordinary G-BLUP (-value = 0.15. Incorporating seedling phenotype information as fixed effects in G-BLUP did not consistently increase accuracy. Overall, levels of prediction accuracy found in this study indicate that GS can be effectively applied to improve stem rust APR in this germplasm, and if genotypes at linked markers are available, modeling these genotypes as fixed effects could lead to better predictions.

Tradeoff between stem hydraulic efficiency and mechanical strength affects leaf-stem allometry in 28 Ficus tree species

NARCIS (Netherlands)

Fan, Ze Xin; Sterck, Frank; Zhang, Shi Bao; Fu, Pei Li; Hao, Guang You

2017-01-01

Leaf-stem allometry is an important spectrum that linked to biomass allocation and life history strategy in plants, although the determinants and evolutionary significance of leaf-stem allometry remain poorly understood. Leaf and stem architectures - including stem area/mass, petiole area/mass,

Biomechanical differences in the stem straightening process among Pinus pinaster provenances. A new approach for early selection of stem straightness.

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Sierra-de-Grado, Rosario; Pando, Valentín; Martínez-Zurimendi, Pablo; Peñalvo, Alejandro; Báscones, Esther; Moulia, Bruno

2008-06-01

Stem straightness is an important selection trait in Pinus pinaster Ait. breeding programs. Despite the stability of stem straightness rankings in provenance trials, the efficiency of breeding programs based on a quantitative index of stem straightness remains low. An alternative approach is to analyze biomechanical processes that underlie stem form. The rationale for this selection method is that genetic differences in the biomechanical processes that maintain stem straightness in young plants will continue to control stem form throughout the life of the tree. We analyzed the components contributing most to genetic differences among provenances in stem straightening processes by kinetic analysis and with a biomechanical model defining the interactions between the variables involved (Fournier's model). This framework was tested on three P. pinaster provenances differing in adult stem straightness and growth. One-year-old plants were tilted at 45 degrees, and individual stem positions and sizes were recorded weekly for 5 months. We measured the radial extension of reaction wood and the anatomical features of wood cells in serial stem cross sections. The integral effect of reaction wood on stem leaning was computed with Fournier's model. Responses driven by both primary and secondary growth were involved in the stem straightening process, but secondary-growth-driven responses accounted for most differences among provenances. Plants from the straight-stemmed provenance showed a greater capacity for stem straightening than plants from the sinuous provenances mainly because of (1) more efficient reaction wood (higher maturation strains) and (2) more pronounced secondary-growth-driven autotropic decurving. These two process-based traits are thus good candidates for early selection of stem straightness, but additional tests on a greater number of genotypes over a longer period are required.

Rooting of hybrid clones of Populus tremula L. x P. tremuloides Michx. by stem cuttings derived from micropropagated plants

Energy Technology Data Exchange (ETDEWEB)

Qibin Yu [Univ. of Helsinki (Finland). Dept. of Plant Biology; Maentylae, N. [Univ. of Turku (Finland). Dept. of Biology, Plant Physiology and Molecular Biology; Salonen, M. [Finnish Forest Research Inst., Laeyliaeinen (Finland). Haapastensyrjae Breeding Station

2001-07-01

Propagation costs could be cut by replacing part of the micropropagation process with steps involving more traditional techniques. This study explored possibilities for improving existing vegetative propagation techniques for aspen using stem cuttings obtained from micropropagated plants. Vegetative propagation through stem cuttings was studied in 10 micropropagated hybrid aspen clones (Populus tremula L. x P. tremuloides Michx). Cuttings containing one axillary bud were harvested from the same donor plants twice during the growing season: the first harvest in May and the second harvest in July. Rooting percentage was correlated positively with root length, number of roots and height of cutting plant but negatively with length of rooting. The average rooting percentage was 53% in the first harvest and 27% in second harvest. Indole-3-butyric acid treatments (1.2 mM) significantly improved rooting in the second harvest, but not in the first harvest, suggesting different endogenous auxin levels in the cuttings. A significant variation for most traits related to rooting ability was found among the clones, indicating that clonal effects play an important role in the propagation of aspen. Thus, clones with a good response in shoot growth and rooting could be exploited in large-scale propagation using stem cuttings.

Dehydro-alpha-lapachone isolated from Catalpa ovata stems: activity against plant pathogenic fungi.

Science.gov (United States)

Cho, Jun Young; Kim, Hae Young; Choi, Gyung Ja; Jang, Kyoung Soo; Lim, He Kyoung; Lim, Chi Hwan; Cho, Kwang Yun; Kim, Jin-Cheol

2006-05-01

The methanol extract of stems of Catalpa ovata G Don exhibits potent in vivo antifungal activity against Magnaporthe grisea (Hebert) Barr (rice blast) on rice plants, Botrytis cinerea Pers ex Fr (tomato grey mould) and Phytophthora infestans (Mont) de Bary (tomato late blight) on tomato plants, Puccinia recondita Rob ex Desm (wheat leaf rust) on wheat plants and Blumeria graminis (DC) Speer f. sp. hordei Marchal (barley powdery mildew) on barley plants. An antifungal substance was isolated and identified as dehydro-alpha-lapachone from mass and nuclear magnetic resonance spectral data. It completely inhibited the mycelial growth of B. cinerea, Colletotrichum acutatum Simmonds, Colletotrichum gloeosporioides Simmonds, M. grisea and Pythium ultimum Trow over a range of 0.4-33.3 mg litre(-1). It also controlled the development of rice blast, tomato late blight, wheat leaf rust, barley powdery mildew and red pepper anthracnose (Colletotrichum coccodes (Wallr) S Hughes). The chemical was particularly effective in suppressing red pepper anthracnose by 95% at a concentration of 125 mg litre(-1). Copyright 2006 Society of Chemical Industry.

Stem cell organization in Arabidopsis

NARCIS (Netherlands)

Wendrich, J.R.

2016-01-01

Growth of plant tissues and organs depends on continuous production of new cells, by niches of stem cells. Stem cells typically divide to give rise to one differentiating daughter and one non-differentiating daughter. This constant process of self-renewal ensures that the niches of stem cells or

On the Relationship between Aquatic Plant Stem Characteristics and Drag Force: Is a Modeling Application Possible?

Directory of Open Access Journals (Sweden)

Anna Maria Łoboda

2018-04-01

Full Text Available This paper presents a basic model that shows the relationship between the diameter of a stem and its flexural rigidity. The model was developed from experimental measurements of biomechanical traits (i.e., tensile and bending traits like maximum forces, stresses, moduli of elasticity, flexural rigidity, strain of three freshwater macrophyte species (Elodea canadensis Michx., Potamogeton pectinatus L., and P. crispus L., reflecting the seasonal changes in plant biomechanics throughout the vegetative season. These were obtained with the use of a bench-top testing machine in 2016 and 2017. The presented calculations are based on the ratio of drag-to-bending forces, in which the flexural rigidity plays a key role. The proposed model has the form EI = adb, and two approaches based on a regression analysis were applied to determine the parameters of the model—a and b. In the first method, the parameters were identified separately for each day of measurement, while in the second method, the coefficient b was calculated for all data from all days as a unified number for individual plants. The results suggest that coefficient b may provide information about the proportion of changes in drag forces depending on plant stiffness. The values of this coefficient were associated with the shape of the stem cross-section. The more circular the cross-section, the closer the value of the parameter was to 1. The parameter values were 1.60 for E. canadensis, 1.98 for P. pectinatus, and 2.46 for P. crispus. Moreover, this value also depended on the density of the cross-section structure. Most of the results showed that with an increase in stem diameter, the ratio between the drag and bending forces decreased, which led to fewer differences between these two forces. The model application may be introduced in many laboratory measurements of flow–biota interactions as well as in aquatic plant management applications. The implementation of these results in control

Arabinogalactan Proteins Accumulate in the Cell Walls of Searching Hyphae of the Stem Parasitic Plants, Cuscuta campestris and Cuscuta japonica.

Science.gov (United States)

Hozumi, Akitaka; Bera, Subhankar; Fujiwara, Daiki; Obayashi, Takeshi; Yokoyama, Ryusuke; Nishitani, Kazuhiko; Aoki, Koh

2017-11-01

Stem parasitic plants (Cuscuta spp.) develop a specialized organ called a haustorium to penetrate their hosts' stem tissues. To reach the vascular tissues of the host plant, the haustorium needs to overcome the physical barrier of the cell wall, and the parasite-host interaction via the cell wall is a critical process. However, the cell wall components responsible for the establishment of parasitic connections have not yet been identified. In this study, we investigated the spatial distribution patterns of cell wall components at a parasitic interface using parasite-host complexes of Cuscuta campestris-Arabidopsis thaliana and Cuscuta japonica-Glycine max. We focused on arabinogalactan proteins (AGPs), because AGPs accumulate in the cell walls of searching hyphae of both C. campestris and C. japonica. We found more AGPs in elongated haustoria than in pre haustoria, indicating that AGP accumulation is developmentally regulated. Using in situ hybridization, we identified five genes in C. campestris that encode hyphal-expressed AGPs that belong to the fasciclin-like AGP (FLA) family, which were named CcFLA genes. Three of the five CcFLA genes were expressed in the holdfast, which develops on the Cuscuta stem epidermis at the attachment site for the host's stem epidermis. Our results suggest that AGPs are involved in hyphal elongation and adhesion to host cells, and in the adhesion between the epidermal tissues of Cuscuta and its host. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Calpain-Mediated positional information directs cell wall orientation to sustain plant stem cell activity, growth and development

Science.gov (United States)

Eukaryotic development and stem cell control depend on the integration of cell positional sensing with cell cycle control and cell wall positioning, yet few factors that directly link these events are known. The DEFECTIVE KERNEL1 (DEK1) gene encoding the unique plant calpain protein is fundamental f...

Donor of winter rye short stem (Secale cereale L. Gnom 1

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В. В. Скорик

2013-08-01

Full Text Available The article proves that the genetic cluster analysis using of parents – offspring system at the period of 38 generations of directional intentional selection to short stem, the height of winter rye plants has been reduced less than 90 cm with simultaneously productivity integral components increasing. Directional selection on parent plants short stem has revealed pleiotropic effects to increasing averages of productivity yield capacity, spike length, flowers number, grains, and short stem and simultaneously its productivity reducing, plant and weight reducing of 100 direct descendants grains. Plant height donor of short stem Gnome 1 has been controlled prevailing by genetic factors and has been less influenced by environmental conditions. Selection by enlargement of elite plants grains has predetermined genetically increasing of the average height of families in the next generation without the concept selection requirements satisfaction. Therefore, the directed selections, by the structural analysis results, are annually held in two phases, first – to the expressed short stem and then among of them – to the high weight of 100 grains per plant and desirable productivity elements. A creative dominant short stem donor with stems up to 90 cm and a weight of 100 grains per plant more than 4.0 g has been made. A short stem spike shortness donor Dwarf 1possesses a significant reserve of common genetic mutation of quantitative characteristics, which can be used by direct and indirect selection. This population has been represented by its large amount, in order to enhance capabilities of directional selection plants short stem providing with the desired productivity components during the studying. Informative additive genetic cluster analysis is high. Plants productivity is considered to be extremely complicated selection characteristics, including many component constituents parts related genetically. One of these traits changing inevitably causes

Expressing OsMPK4 Impairs Plant Growth but Enhances the Resistance of Rice to the Striped Stem Borer Chilo suppressalis

OpenAIRE

Xiaoli Liu; Jiancai Li; Liping Xu; Qi Wang; Yonggen Lou

2018-01-01

Mitogen-activated protein kinases (MPKs) play a central role not only in plant growth and development, but also in plant responses to abiotic and biotic stresses, including pathogens. Yet, their role in herbivore-induced plant defenses and their underlying mechanisms remain largely unknown. Here, we cloned a rice MPK gene, OsMPK4, whose expression was induced by mechanical wounding, infestation of the striped stem borer (SSB) Chilo suppressalis, and treatment with jasmonic acid (JA), but not ...

Stem girdling evidences a trade-off between cambial activity and sprouting and dramatically reduces plant transpiration due to feedback inhibition of photosynthesis and hormone signaling.

Science.gov (United States)

López, Rosana; Brossa, Ricard; Gil, Luis; Pita, Pilar

2015-01-01

The photosynthesis source-sink relationship in young Pinus canariensis seedlings was modified by stem girdling to investigate sprouting and cambial activity, feedback inhibition of photosynthesis, and stem and root hydraulic capacity. Removal of bark tissue showed a trade-off between sprouting and diameter growth. Above the girdle, growth was accelerated but the number of sprouts was almost negligible, whereas below the girdle the response was reversed. Girdling resulted in a sharp decrease in whole plant transpiration and root hydraulic conductance. The reduction of leaf area after girdling was strengthened by the high levels of abscisic acid found in buds which pointed to stronger bud dormancy, preventing a new needle flush. Accumulation of sugars in leaves led to a coordinated reduction in net photosynthesis (AN) and stomatal conductance (gS) in the short term, but later (gS below 0.07 mol m(-2) s(-1)) AN decreased faster. The decrease in maximal efficiency of photosystem II (FV/FM) and the operating quantum efficiency of photosystem II (ΦPSII) in girdled plants could suggest photoprotection of leaves, as shown by the vigorous recovery of AN and ΦPSII after reconnection of the phloem. Stem girdling did not affect xylem embolism but increased stem hydraulic conductance above the girdle. This study shows that stem girdling affects not only the carbon balance, but also the water status of the plant.

Stem girdling evidences a trade-off between cambial activity and sprouting and dramatically reduces plant transpiration due to feedback inhibition of photosynthesis and hormone signaling

Directory of Open Access Journals (Sweden)

Rosana eLópez

2015-04-01

Full Text Available The photosynthesis source-sink relationship in young Pinus canariensis seedlings was modified by stem girdling to investigate sprouting and cambial activity, feedback inhibition of photosynthesis, and stem and root hydraulic capacity. Removal of bark tissue showed a trade-off between sprouting and diameter growth. Above the girdle, growth was accelerated but the number of sprouts was almost negligible, whereas below the girdle the response was reversed. Girdling resulted in a sharp decrease in whole plant transpiration and root hydraulic conductance. The reduction of leaf area after girdling was strengthened by the high levels of ABA found in buds which pointed to stronger bud dormancy, preventing a new needle flush. Accumulation of sugars in leaves led to a coordinated reduction in net photosynthesis (AN and stomatal conductance (gS in the short term, but later (gS below 0.07 mol m-2 s-1 AN decreased faster. The decrease in maximal efficiency of photosystem II (FV/FM and the operating quantum efficiency of photosystem II (ΦPSII in girdled plants could suggest photoprotection of leaves, as shown by the vigorous recovery of AN and ΦPSII after reconnection of the phloem. Stem girdling did not affect xylem embolism but increased stem hydraulic conductance above the girdle. This study shows that stem girdling affects not only the carbon balance, but also the water status of the plant.

Stem characteristics of two forage maize (Zea mays L.) cultivars varying in whole plant digestibility. III. Intra-stem variability in anatomy, chemical composition and in vitro rumen fermentation

NARCIS (Netherlands)

Boon, E.J.M.C.; Struik, P.C.; Tamminga, S.; Engels, F.M.; Cone, J.W.

2008-01-01

The internodes of forage maize (Zea mays L.) stems were studied at anthesis for variation in anatomy and chemical composition in relation to digestibility. The study was carried out with a short (Vitaro) and a tall (Volens) cultivar differing in whole-plant digestibility, both of which were grown in

Effects of neolignans from the stem bark of Magnolia obovata on plant pathogenic fungi.

Science.gov (United States)

Choi, N H; Choi, G J; Min, B-S; Jang, K S; Choi, Y H; Kang, M S; Park, M S; Choi, J E; Bae, B K; Kim, J-C

2009-06-01

To characterize antifungal principles from the methanol extract of Magnolia obovata and to evaluate their antifungal activities against various plant pathogenic fungi. Four neolignans were isolated from stem bark of M. obovata as antifungal principles and identified as magnolol, honokiol, 4-methoxyhonokiol and obovatol. In mycelial growth inhibition assay, both magnolol and honokiol displayed more potent antifungal activity than 4-methoxyhonokiol and obovatol. Both magnolol and honokiol showed similar in vivo antifungal spectrum against seven plant diseases tested; both compounds effectively suppressed the development of rice blast, tomato late blight, wheat leaf rust and red pepper anthracnose. 4-Methoxyhonokiol and obovatol were highly active to only rice blast and wheat leaf rust respectively. The extract of M. obovata and four neolignans had potent in vivo antifungal activities against plant pathogenic fungi. Neolignans from Magnolia spp. can be used and suggested as a novel antifungal lead compound for the development of new fungicide and directly as a natural fungicide for the control of plant diseases such as rice blast and wheat leaf rust.

Non-invasive plant growth measurements for detection of blue-light dose response of stem elongation in Chrysanthemum morifolium

DEFF Research Database (Denmark)

Kjær, Katrine Heinsvig

2012-01-01

. In the present study a non-invasive plant growth sensor (PlantEye, Phenospex B.V, Heerlen, NL) was tested in analysing changes in diurnal stem elongation patterns and plant height in response to the spectral quality of the light environment. Plants were grown in four different LED supplemental lighting...... treatments with 0%, 12.5%, 18.5% and 22.5% blue light under greenhouse conditions in winter (18 h day/4 h night). The non-invasive measurements were carried out automatically every four hour with three repetitions, and supported by manual measurements of plant height every third day. A strong linear relation...... between the non-invasive measurements and manual measurements of plant height was achieved, and a blue-light dose-response showing a decrease in plant height in relation to an increase in blue light was demonstrated. However, the non-invasive plant growth sensor was not able to distinguish between diurnal...

Place Based STEM: Leveraging Local Resources to Engage K-12 Teachers in Teaching Integrated STEM and for Addressing the Local STEM Pipeline

Energy Technology Data Exchange (ETDEWEB)

Dr. Louis Nadelson; Anne Louise Seifert; Meagan McKinney

2014-06-01

for teaching integrated STEM and provide a relevant context for teaching STEM content. Workplace presentations made by place-based STEM experts and provided teachers field trips to place-base STEM industries and business such as manufacturing plants, waste water treatment systems, mines, nature parks, food processing plants, research, hospitals, and laboratory facilities. We researched the 425 participants’ conceptions of place-based STEM prior to and after their taking part in the summer institutes, which included fieldtrips. Our findings revealed substantial increase in our participants’ knowledge, interest, and plans to use place-based resources for teaching integrated STEM. We detail the data analysis and provide a theoretical foundation and justification for the importance of place-based STEM to address the STEM pipeline for the future workforce.

Estrangulamento do caule do cafeeiro, causado pelo frio Low temperature-induced stem strangulation of young coffee plants

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Coaracy M. Franco

1960-01-01

Full Text Available Com o objetivo de investigar se o estrangulamento do caule de cafeeiros novos, observado em alguns anos de inverno rigoroso, poderia ser conseqüência do acúmulo de camadas de ar frio nas proximidades do solo, tratou-se com temperaturas baixas a haste de plantas com cêrca de seis meses de idade. O tratamento consistiu em se fazer circular salmoura refrigerada ao redor do caule, sem, entretanto, entrar em contato com êste. Obteve-se o estrangulamento com o emprêgo de vários tratamentos que incluiam temperaturas de - 2 a - 6º C. Uma planta tratada com temperatura de - 5 a - 7º C morreu duas semanas após o tratamento. Plantas tratadas por duas horas com as temperaturas de 0 a - 2º C não exibiram estrangulamento nem qualquer outro sintoma de anormalidade.A strangulation of the stem of young coffee plants a few inches above ground has been observed in some years after a cold winter. To know if this strangulation could be caused by the action of a layer of cold air that had settled over the surface of the soil as has been suggested (1, an experiment was carried out wich consisted of circulating cold water around the stem for a certain period of time. To accomplish this a special apparatus was mode using plexiglass. To obtain temperatures below the freezing point, pre-chilled salt water was used. To avoid an injurious direct contact of brine with the stem, this was wrapped with aluminum foil which was made waterproof. Two plants subjected to temperature treatments of 0° to - 2° C survived without damage. All treatments with temperatures below - 2° C resulted in strangulation and in the case of the coldest treatment used (- 5 to - 7° C in the death of the plant.

Detecting Stems in Dense and Homogeneous Forest Using Single-Scan TLS

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Shaobo Xia

2015-10-01

Full Text Available Stem characteristics of plants are of great importance to both ecology study and forest management. Terrestrial laser scanning (TLS may provide an effective way to characterize the fine-scale structures of vegetation. However, clumping plants, dense foliage and thin structure could intensify the shadowing effect and pose a series of problems in identifying stems, distinguishing neighboring stems, and merging disconnected stem parts in point clouds. This paper presents a new method to automatically detect stems in dense and homogeneous forest using single-scan TLS data. Stem points are first identified with a two-scale classification method. Then a clustering approach is used to group the candidate stem points. Finally, a direction-growing algorithm based on a simple stem curve model is applied to merge stem points. Field experiments were carried out in two different bamboo plots with a stem density of about 7500 stems/ha. Overall accuracy of the stem detection is 88% and the quality of detected stems is mainly affected by the shadowing effect. Results indicate that the proposed method is feasible and effective in detection of bamboo stems using TLS data, and can be applied to other species of single-stem plants in dense forests.

Water status and gas exchange of umbu plants (Spondias tuberosa Arr. Cam.) propagated by seeds and stem cuttings.

OpenAIRE

LIMA FILHO, J. M. P.

2008-01-01

The experiment was carried out at the Embrapa Semi-Árido, Petrolina-PE, Brazil, in order to study the physiological responses of umbu plants propagated by seeds and by stem cuttings under water stress conditions, based on leaf water potential and gas exchange measurements. Data were collected in one-year plants established in pots containing 30 kg of a sandy soil and submitted to twenty-day progressive soil water deficit. The evaluations were based on leaf water potential and gas exchange dat...

Preliminary Studies on the Occurrence of Stem Borers and the ...

African Journals Online (AJOL)

A field experiment was carried out to study the occurrence of stem-borers and the incidence of stalk rot under varying population densities (64,000, 32,000, and 21,333 plants/ha) of two common cultivars (TZSR-Y and DMRZ-Y) of maize. Whereas the percentage of plants with stem borers infestation and those with stem ...

Optimal planting systems for cut gladiolus and stock production

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Iftikhar Ahmad

2017-10-01

Full Text Available A study was conducted to elucidate the effect of different planting systems, videlicet (viz. flat, ridge, and raised bed system on growth, yield and quality of gladiolus and stock. Corms of ‘Rose Supreme’ and ‘White Prosperity’ gladiolus and seedlings of ‘Cheerful White’, ‘Lucinda Dark Rose Double’ and ‘Lucinda Dark Rose Single’ stock were planted on different planting systems in individual experiments for each species. Gladiolus had similar good quality production irrespective of planting systems with numerical superiority of ridge planting, which produced longer stems with higher stem fresh weight, but delayed corm sprouting by ca. 1 d compared to raised bed or flat planting system. Among cultivars, ‘Rose Supreme’ produced higher number of florets per spike, taller stems with longer spikes, higher fresh weight of stems and higher number of cormels than ‘White Prosperity’. Stock plants grown on flat beds produced stems with greater stem length, leaf area and fresh weight of stems compared to ridge or raised bed planting systems. Plants grown on ridges produced the highest stem diameter, number of leaves per plant, total leaf chlorophyll contents, and number of flowers per spike. ‘Cheerful White’ and ‘Lucinda Dark Rose Double’ performed best by producing good quality stems in shorter period compared to ‘Lucinda Dark Rose Single’. In summary, gladiolus should be grown on ridges, while stock may be planted on flat beds for higher yields of better quality flowers.

AVOCADO SEEDLINGS MULTIPLE STEMS PRODUCTION

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MARCUS VINICIUS SANDOVAL PAIXÃO

2016-01-01

Full Text Available ABSTRACT This study aimed to evaluate the potential of multi-stems in avocado seeds according to their mass as well as the adventitious rooting of multi-stem budding with or without the use of auxin. The research was carried out at the Vegetation House of Federal Institute of Espírito Santo, Campus Santa Teresa -ES, with seeds of different masses: 100 g, in which each experimental unit was made of five seeds, distributed within five repetitions, under a completely randomized design. The seeds were put to germinate and the percentage number of emergence and multiple stems were evaluated. After 150 days, the following evaluations were carried out: survival of rooted cuttings; number of leaves; stem diameter; root length; root volume; root and shoot fresh mass; root and shoot dry mass; shoot height; absolute growth and shoot growth rate; shoot dry weight/root dry mass ratio; shoot height/stem diameter ratio; shoot height/root length and Dickson's quality index ratio. Avocado seeds with mass over 100 g and between 81-100 g presented higher percentage of multiple stems. Rods over 20 cm that were not treated with IBA (indole-3-butyric acid resulted on avocado plants of better quality. The use of IBA (2000 mg L-1 does not affect the rooting and growth of avocado's multi-stem plants.

Phylogeny in Defining Model Plants for Lignocellulosic Ethanol Production: A Comparative Study of Brachypodium distachyon, Wheat, Maize, and Miscanthus x giganteus Leaf and Stem Biomass

Science.gov (United States)

Meineke, Till; Manisseri, Chithra; Voigt, Christian A.

2014-01-01

The production of ethanol from pretreated plant biomass during fermentation is a strategy to mitigate climate change by substituting fossil fuels. However, biomass conversion is mainly limited by the recalcitrant nature of the plant cell wall. To overcome recalcitrance, the optimization of the plant cell wall for subsequent processing is a promising approach. Based on their phylogenetic proximity to existing and emerging energy crops, model plants have been proposed to study bioenergy-related cell wall biochemistry. One example is Brachypodium distachyon, which has been considered as a general model plant for cell wall analysis in grasses. To test whether relative phylogenetic proximity would be sufficient to qualify as a model plant not only for cell wall composition but also for the complete process leading to bioethanol production, we compared the processing of leaf and stem biomass from the C3 grasses B. distachyon and Triticum aestivum (wheat) with the C4 grasses Zea mays (maize) and Miscanthus x giganteus, a perennial energy crop. Lambda scanning with a confocal laser-scanning microscope allowed a rapid qualitative analysis of biomass saccharification. A maximum of 108–117 mg ethanol·g−1 dry biomass was yielded from thermo-chemically and enzymatically pretreated stem biomass of the tested plant species. Principal component analysis revealed that a relatively strong correlation between similarities in lignocellulosic ethanol production and phylogenetic relation was only given for stem and leaf biomass of the two tested C4 grasses. Our results suggest that suitability of B. distachyon as a model plant for biomass conversion of energy crops has to be specifically tested based on applied processing parameters and biomass tissue type. PMID:25133818

Effects of plant growth promoting rhizobacteria (PGPR on rooting and root growth of kiwifruit (Actinidia deliciosa stem cuttings

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YASAR ERTURK

2010-01-01

Full Text Available The effects of plant growth promoting rhizobacteria (PGPR on the rooting and root growth of semi-hardwood and hardwood kiwifruit stem cuttings were investigated. The PGPR used were Bacillus RC23, Paenibacillus polymyxa RC05, Bacillus subtilis OSU142, Bacillus RC03, Comamonas acidovorans RC41, Bacillus megaterium RC01 and Bacillus simplex RC19. All the bacteria showed indole-3-acetic acid (IAA producing capacity. Among the PGPR used, the highest rooting ratios were obtained at 47.50% for semi-hardwood stem cuttings from Bacillus RC03 and Bacillus simplex RC19 treatments and 42.50% for hardwood stem cuttings from Bacillus RC03. As well, Comamonas acidovorans RC41 inoculations indicated higher value than control treatments. The results suggest that these PGPR can be used in organic nursery material production and point to the feasibility of synthetic auxin (IBA replacement by organic management based on PGPR.

Transcript Lifetime Is Balanced between Stabilizing Stem-Loop Structures and Degradation-Promoting Polyadenylation in Plant Mitochondria

Science.gov (United States)

Kuhn, Josef; Tengler, Ulrike; Binder, Stefan

2001-01-01

To determine the influence of posttranscriptional modifications on 3′ end processing and RNA stability in plant mitochondria, pea atp9 and Oenothera atp1 transcripts were investigated for the presence and function of 3′ nonencoded nucleotides. A 3′ rapid amplification of cDNA ends approach initiated at oligo(dT)-adapter primers finds the expected poly(A) tails predominantly attached within the second stem or downstream of the double stem-loop structures at sites of previously mapped 3′ ends. Functional studies in a pea mitochondrial in vitro processing system reveal a rapid removal of the poly(A) tails up to termini at the stem-loop structure but little if any influence on further degradation of the RNA. In contrast 3′ poly(A) tracts at RNAs without such stem-loop structures significantly promote total degradation in vitro. To determine the in vivo identity of 3′ nonencoded nucleotides more accurately, pea atp9 transcripts were analyzed by a direct anchor primer ligation-reverse transcriptase PCR approach. This analysis identified maximally 3-nucleotide-long nonencoded extensions most frequently of adenosines combined with cytidines. Processing assays with substrates containing homopolymer stretches of different lengths showed that 10 or more adenosines accelerate RNA processivity, while 3 adenosines have no impact on RNA life span. Thus polyadenylation can generally stimulate the decay of RNAs, but processivity of degradation is almost annihilated by the stabilizing effect of the stem-loop structures. These antagonistic actions thus result in the efficient formation of 3′ processed and stable transcripts. PMID:11154261

Carbon isotopic composition of legumes with photosynthetic stems from Mediterranean and desert habitats

International Nuclear Information System (INIS)

Nilsen, E.T.; Sharifi, M.R.

1997-01-01

The carbon isotopic compositions of leaves and stems of woody legumes growing in coastal mediterranean and inland desert sites in California were compared. The overall goal was to determine what factors were most associated with the carbon isotope composition of photosynthetic stems in these habitats. The carbon isotope signature (delta 13C) of photosynthetic stems was less negative than that of leaves on the same plants by an average of 1.51 +/- 0.42 per thousand. The delta 13C of bark (cortical chlorenchyma and epidermis) was more negative than that of wood (vascular tissue and pith) from the same plant for all species studied on all dates. Desert woody legumes had a higher delta 13C (less negative) and a lower intercellular CO2 concentration (Ci) (for both photosynthetic tissues) than that of woody legumes from mediterranean climate sites. Differences in the delta 13C of stems among sites could be entirely accounted for by differences among site air temperatures. Thus, the delta 13C composition of stems did not indicate a difference in whole-plant integrated water use efficiency (WUE) among sites. In contrast, stems on all plants had a lower stem Ci and a higher delta 13C than leaves on the same plant, indicating that photosynthetic stems improve long-term, whole-plant water use efficiency in a diversity of species

Parasitic plants of the genus Cuscuta and their interaction with susceptible and resistant host plants

Directory of Open Access Journals (Sweden)

Bettina eKaiser

2015-02-01

Full Text Available By comparison with plant-microbe interaction, little is known about the interaction of parasitic plants with their hosts. Plants of the genus Cuscuta belong to the family of Cuscutaceae and comprise about 200 species, all of which live as stem holoparasites on other plants. Cuscuta spp. possess no roots nor fully expanded leaves and the vegetative portion appears to be a stem only. The parasite winds around plants and penetrates the host stems via haustoria, forming direct connections to the vascular bundles of their hosts to withdraw water, carbohydrates and other solutes. Besides susceptible hosts, a few plants exist that exhibit an active resistance against infestation by Cuscuta spp. For example, cultivated tomato (Solanum lycopersicum fends off Cuscuta reflexa by means of a hypersensitive-type response occurring in the early penetration phase. This report on the plant-plant dialogue between Cuscuta spp. and its host plants focuses on the incompatible interaction of Cuscuta reflexa with tomato.

Parasitic plants of the genus Cuscuta and their interaction with susceptible and resistant host plants.

Science.gov (United States)

Kaiser, Bettina; Vogg, Gerd; Fürst, Ursula B; Albert, Markus

2015-01-01

By comparison with plant-microbe interaction, little is known about the interaction of parasitic plants with their hosts. Plants of the genus Cuscuta belong to the family of Cuscutaceae and comprise about 200 species, all of which live as stem holoparasites on other plants. Cuscuta spp. possess no roots nor fully expanded leaves and the vegetative portion appears to be a stem only. The parasite winds around plants and penetrates the host stems via haustoria, forming direct connections to the vascular bundles of their hosts to withdraw water, carbohydrates, and other solutes. Besides susceptible hosts, a few plants exist that exhibit an active resistance against infestation by Cuscuta spp. For example, cultivated tomato (Solanum lycopersicum) fends off Cuscuta reflexa by means of a hypersensitive-type response occurring in the early penetration phase. This report on the plant-plant dialog between Cuscuta spp. and its host plants focuses on the incompatible interaction of C. reflexa with tomato.

The evolutionary fate of phenotypic plasticity and functional traits under domestication in manioc: changes in stem biomechanics and the appearance of stem brittleness.

Science.gov (United States)

Ménard, Léa; McKey, Doyle; Mühlen, Gilda S; Clair, Bruno; Rowe, Nick P

2013-01-01

Domestication can influence many functional traits in plants, from overall life-history and growth form to wood density and cell wall ultrastructure. Such changes can increase fitness of the domesticate in agricultural environments but may negatively affect survival in the wild. We studied effects of domestication on stem biomechanics in manioc by comparing domesticated and ancestral wild taxa from two different regions of greater Amazonia. We compared mechanical properties, tissue organisation and wood characteristics including microfibril angles in both wild and domesticated plants, each growing in two different habitats (forest or savannah) and varying in growth form (shrub or liana). Wild taxa grew as shrubs in open savannah but as lianas in overgrown and forested habitats. Growth form plasticity was retained in domesticated manioc. However, stems of the domesticate showed brittle failure. Wild plants differed in mechanical architecture between shrub and liana phenotypes, a difference that diminished between shrubs and lianas of the domesticate. Stems of wild plants were generally stiffer, failed at higher bending stresses and were less prone to brittle fracture compared with shrub and liana phenotypes of the domesticate. Biomechanical differences between stems of wild and domesticated plants were mainly due to changes in wood density and cellulose microfibril angle rather than changes in secondary growth or tissue geometry. Domestication did not significantly modify "large-scale" trait development or growth form plasticity, since both wild and domesticated manioc can develop as shrubs or lianas. However, "finer-scale" developmental traits crucial to mechanical stability and thus ecological success of the plant were significantly modified. This profoundly influenced the likelihood of brittle failure, particularly in long climbing stems, thereby also influencing the survival of the domesticate in natural situations vulnerable to mechanical perturbation. We

The evolutionary fate of phenotypic plasticity and functional traits under domestication in manioc: changes in stem biomechanics and the appearance of stem brittleness.

Directory of Open Access Journals (Sweden)

Léa Ménard

Full Text Available Domestication can influence many functional traits in plants, from overall life-history and growth form to wood density and cell wall ultrastructure. Such changes can increase fitness of the domesticate in agricultural environments but may negatively affect survival in the wild. We studied effects of domestication on stem biomechanics in manioc by comparing domesticated and ancestral wild taxa from two different regions of greater Amazonia. We compared mechanical properties, tissue organisation and wood characteristics including microfibril angles in both wild and domesticated plants, each growing in two different habitats (forest or savannah and varying in growth form (shrub or liana. Wild taxa grew as shrubs in open savannah but as lianas in overgrown and forested habitats. Growth form plasticity was retained in domesticated manioc. However, stems of the domesticate showed brittle failure. Wild plants differed in mechanical architecture between shrub and liana phenotypes, a difference that diminished between shrubs and lianas of the domesticate. Stems of wild plants were generally stiffer, failed at higher bending stresses and were less prone to brittle fracture compared with shrub and liana phenotypes of the domesticate. Biomechanical differences between stems of wild and domesticated plants were mainly due to changes in wood density and cellulose microfibril angle rather than changes in secondary growth or tissue geometry. Domestication did not significantly modify "large-scale" trait development or growth form plasticity, since both wild and domesticated manioc can develop as shrubs or lianas. However, "finer-scale" developmental traits crucial to mechanical stability and thus ecological success of the plant were significantly modified. This profoundly influenced the likelihood of brittle failure, particularly in long climbing stems, thereby also influencing the survival of the domesticate in natural situations vulnerable to mechanical

Regulation of plant vascular stem cells by endodermis-derived EPFL-family peptide hormones and phloem-expressed ERECTA-family receptor kinases.

Science.gov (United States)

Uchida, Naoyuki; Tasaka, Masao

2013-12-01

Plant vasculatures are complex tissues consisting of (pro)cambium, phloem, and xylem. The (pro)cambium serves as vascular stem cells that produce all vascular cells. The Arabidopsis ERECTA (ER) receptor kinase is known to regulate the architecture of inflorescence stems. It was recently reported that the er mutation enhances a vascular phenotype induced by a mutation of TDR/PXY, which plays a significant role in procambial proliferation, suggesting that ER participates in vascular development. However, detailed molecular mechanisms of the ER-dependent vascular regulation are largely unknown. Here, this work found that ER and its paralogue, ER-LIKE1, were redundantly involved in procambial development of inflorescence stems. Interestingly, their activity in the phloem was sufficient for vascular regulation. Furthermore, two endodermis-derived peptide hormones, EPFL4 and EPFL6, were redundantly involved in such regulation. It has been previously reported that EPFL4 and EPFL6 act as ligands of phloem-expressed ER for stem elongation. Therefore, these findings indicate that cell-cell communication between the endodermis and the phloem plays an important role in procambial development as well as stem elongation. Interestingly, similar EPFL-ER modules control two distinct developmental events by slightly changing their components: the EPFL4/6-ER module for stem elongation and the EPFL4/6-ER/ERL1 module for vascular development.

Identification of WOX family genes in Selaginella kraussiana for studies on stem cells and regeneration in lycophytes

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Yachao eGe

2016-02-01

Full Text Available Plant stem cells give rise to all tissues and organs and also serve as the source for plant regeneration. The organization of plant stem cells has undergone a progressive change from simple to complex during the evolution of vascular plants. Most studies on plant stem cells have focused on model angiosperms, the most recently diverged branch of vascular plants. However, our knowledge of stem cell function in other vascular plants is limited. Lycophytes and euphyllophytes (ferns, gymnosperms, and angiosperms are two existing branches of vascular plants that separated more than 400 million years ago. Lycophytes retain many of the features of early vascular plants. Based on genome and transcriptome data, we identified WUSCHEL-RELATED HOMEOBOX (WOX genes in Selaginella kraussiana, a model lycophyte that is convenient for in vitro culture and observations of organ formation and regeneration. WOX genes are key players controlling stem cells in plants. Our results showed that the S. kraussiana genome encodes at least eight members of the WOX family, which represent an early stage of WOX family evolution. Identification of WOX genes in S. kraussiana could be a useful tool for molecular studies on the function of stem cells in lycophytes.

Assessment of maize stem borer damage on hybrid maize varieties in Chitwan, Nepal

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Buddhi Bahadur Achhami

2015-12-01

Full Text Available Maize is the second most important cereal crop in Nepal. However, national figure of grain production still remains below than the world's average grain production per unit area. Thus, this experiment was designed to determine the suitable time of maize planting, and to assess the peak period of one of the major insects, maize stem borer, in Chitwan condition. The results showed that plant damage percentage as per the maize planting month varies significantly, and the average plant damage percentage by stem borer was up to 18.11%. Length of the feeding tunnel in maize stem was significantly higher in January than July. In case of exit holes made by borer counted more than four holes per plant that were planted in the month of January. All in all, except the tunnel length measurement per plant, we observed similar pattern in other borer damage parameters such as exit whole counts and plant damage percentage within the tested varieties. Stem borer damage was not significantly affect on grain yield.

Mechanical analysis of the strains generated by water tension in plant stems. Part II: strains in wood and bark and apparent compliance.

Science.gov (United States)

Alméras, Tancrède

2008-10-01

Tree stems shrink in diameter during the day and swell during the night in response to changes in water tension in the xylem. Stem shrinkage can easily be measured in a nondestructive way, to derive continuous information about tree water status. The relationship between the strain and the change in water tension can be evaluated by empirical calibrations, or can be related to the structure of the plant. A mechanical analysis was performed to make this relationship explicit. The stem is modeled as a cylinder made of multiple layers of tissues, including heartwood, sapwood, and inner and outer bark. The effect of changes in water tension on the apparent strain at the surface of a tissue is quantified as a function of parameters defining stem anatomy and the mechanical properties of the tissues. Various possible applications in the context of tree physiology are suggested.

Modelling of tomato stem diameter growth rate based on physiological responses

International Nuclear Information System (INIS)

Li, L.; Tan, J.; Lv, T.

2017-01-01

The stem diameter is an important parameter describing the growth of tomato plant during vegetative growth stage. A stem diameter growth model was developed to predict the response of plant growth under different conditions. By analyzing the diurnal variations of stem diameter in tomato (Solanum lycopersicum L.), it was found that the stem diameter measured at 3:00 am was the representative value as the daily basis of tomato stem diameter. Based on the responses of growth rate in stem diameter to light and temperature, a linear regression relationship was applied to establish the stem diameter growth rate prediction model for the vegetative growth stage in tomato and which was further validated by experiment. The root mean square error (RMSE) and relative error (RE) were used to test the correlation between measured and modeled stem diameter variations. Results showed that the model can be used in prediction for stem diameter growth rate at vegetative growth stage in tomato. (author)

Effect of vanadium on plant growth and its accumulation in plant tissues

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Narumol Vachirapatama

2011-06-01

Full Text Available Hydroponic experiments were conducted to investigate vanadium uptake by Chinese green mustard and tomato plantsand its effect on their growth. Twenty-eight (Chinese green mustard and 79 days (tomato after germination, the plants wereexposed for a further seven days to a solution containing six different concentrations of ammonium metavanadate (0-80 mg/lNH4VO3. The vanadium accumulated in the plant tissues were determined by ion-interaction high performance liquid chromatography,with confirmation by magnetic sector ICP-MS.The results indicated that nutrient solution containing more than 40 mg/l NH4VO3 affected plant growth for bothChinese green mustard and tomato plant. Chinese green mustard grown in the solution containing NH4VO3 at the concentrationsof 40 and 80 mg/l had stem length, number of leaves, dry weight of leaf, stem and root significantly lower than those ofplants grown in the solution containing 0-20 mg/l NH4VO3. Tomato plants were observed to wilt after four days in contactwith the nutrient solutions containing 40 and 80 mg/l NH4VO3. As the vanadium concentrations increased, a resultantdecrease in the stem length, root fresh weight, and fruit fresh weight were noted. The accumulation of vanadium was higher inthe root compared with leaf, stem, or fruit. Measured levels of vanadium, from a nutrient solution containing 40 mg/l NH4VO3,were 328, 340, and 9.66x103 g/g in the leaf, stem and root for Chinese green mustard, and 4.04 and 4.01x103 g/g in the fruitand roots for tomato plants, respectively.

The effect of cutting origin and organic plant growth regulator on the growth of Daun Ungu (Graptophyllum pictum) through stem cutting method

Science.gov (United States)

Pratama, S. P.; Yunus, A.; Purwanto, E.; Widyastuti, Y.

2018-03-01

Graptophyllum pictum is one of medical plants which has important chemical content to treat diseases. Leaf, bark and flower can be used to facilitate menstruation, treat hemorrhoid, constipation, ulcers, ulcers, swelling, and earache. G. pictum is difficult to propagated by seedling due to the long duration of seed formation, thusvegetative propagation is done by stem cutting. The aims of this study are to obtain optimum combination of cutting origin and organic plant growth regulator in various consentration for the growth of Daun Ungu through stem cutting method. This research was conducted at Research center for Medicinal Plant and Traditional DrugTanjungsari, Tegal Gede, Karanganyar in June to August 2016. Origin of cuttings and organic plant growth regulator were used as treatments factor. A completely randomized design (RAL) is used and data were analyzed by F test (ANOVA) with a confidence level of 95%. Any significant differences among treatment followed with Duncan test at a = 5%. The research indicates that longest root was resulted from the treatment of 0,5 ml/l of organic plant growth regulator. The treatment of 1 ml/l is able to increase the fresh and dry weight of root, treatment of 1,5 ml/l of organic plant growth regulator was able to increase the percentage of growing shoots. Treatment of base part as origin of cuttings increases the length, fresh weight and and dry weight of shoot, increase the number of leaves. Interaction treatment between 1 ml/l consentration of organic plant growth regulator and central part origin of cuttings is capable of increasing the leaf area, whereas treatment without organic plant growth regulator and base part as planting material affects the smallest leaf area.

New record of Phytophthora root and stem rot of Lavandula angustifolia

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Leszek B. Orlikowski

2013-12-01

Full Text Available Phytophthora cinnamomi was isolated from rotted root and stem parts of lavender as well as from soil taken from containers with diseased plants. Additionally Botrytis cinerea, Fusarium spp. and Sclerotinia sclerotiorum were often isolated from diseased tissues. P. cinnamomi colonised leaves and stem parts of 4 lavender species in laboratory trials and caused stem rot of plants in greenhouse experiments. Cardinal temperature for in vitro growth were about 7,5 and 32°C with optimum 25-27,5°C. The species colonised stem tissues at temperature ranged from 10° to 32°C.

Quality evaluation of dissolving pulp fabricated from banana plant stem and its potential for biorefinery.

Science.gov (United States)

Das, Atanu Kumar; Nakagawa-Izumi, Akiko; Ohi, Hiroshi

2016-08-20

The study was conducted to evaluate the quality of dissolving pulp of Musa sapientum L. (banana) plant stem and its potential for biorefinery. Introduction of pre-hydrolysis prior to any alkaline pulping process helps to reduce the content of hemicellulose and consequently produce acceptably high content of cellulose pulp. Water pre-hydrolysis was done at 150°C for 90min. The amount of lignin, xylan and glucan in the extracted pre-hydrolysis liquor (PHL) was 1.6, 4.9 and 1.6%, respectively. Pulping of pre-extracted chips was done following soda-AQ, alkaline sulfite and kraft process. The ratio of chip to liquor was 1:7 for both pre-hydrolysis and pulping. The kraft pulping process with 20% active alkali and 25% sulfidity at 150°C for 90min showed the best result. The lowest kappa number was 26.2 with a considerable pulp yield of 32.7%. The pulp was bleached by acidic NaClO2 and the consistency was 10% based on air-dried pulp. The lowest amount of 7% NaClO2 was used for the bleaching sequence of D0ED1ED2. After D0ED1ED2 bleaching, the pulp showed that α-cellulose, brightness and ash were 91.9, 77.9 and 1.6% respectively. The viscosity was 19.9cP. Hence, there is a possibility to use banana plant stem as a raw material for dissolving grade pulp and other bioproducts. Copyright © 2016 Elsevier Ltd. All rights reserved.

Nitroaromatic detection and infrared communication from wild-type plants using plant nanobionics

Science.gov (United States)

Wong, Min Hao; Giraldo, Juan P.; Kwak, Seon-Yeong; Koman, Volodymyr B.; Sinclair, Rosalie; Lew, Tedrick Thomas Salim; Bisker, Gili; Liu, Pingwei; Strano, Michael S.

2017-02-01

Plant nanobionics aims to embed non-native functions to plants by interfacing them with specifically designed nanoparticles. Here, we demonstrate that living spinach plants (Spinacia oleracea) can be engineered to serve as self-powered pre-concentrators and autosamplers of analytes in ambient groundwater and as infrared communication platforms that can send information to a smartphone. The plants employ a pair of near-infrared fluorescent nanosensors--single-walled carbon nanotubes (SWCNTs) conjugated to the peptide Bombolitin II to recognize nitroaromatics via infrared fluorescent emission, and polyvinyl-alcohol functionalized SWCNTs that act as an invariant reference signal--embedded within the plant leaf mesophyll. As contaminant nitroaromatics are transported up the roots and stem into leaf tissues, they accumulate in the mesophyll, resulting in relative changes in emission intensity. The real-time monitoring of embedded SWCNT sensors also allows residence times in the roots, stems and leaves to be estimated, calculated to be 8.3 min (combined residence times of root and stem) and 1.9 min mm-1 leaf, respectively. These results demonstrate the ability of living, wild-type plants to function as chemical monitors of groundwater and communication devices to external electronics at standoff distances.

Removal ratio of gaseous toluene and xylene transported from air to root zone via the stem by indoor plants.

Science.gov (United States)

Kim, K J; Kim, H J; Khalekuzzaman, M; Yoo, E H; Jung, H H; Jang, H S

2016-04-01

This work was designed to investigate the removal efficiency as well as the ratios of toluene and xylene transported from air to root zone via the stem and by direct diffusion from the air into the medium. Indoor plants (Schefflera actinophylla and Ficus benghalensis) were placed in a sealed test chamber. Shoot or root zone were sealed with a Teflon bag, and gaseous toluene and xylene were exposed. Removal efficiency of toluene and total xylene (m, p, o) was 13.3 and 7.0 μg·m(-3)·m(-2) leaf area over a 24-h period in S. actinophylla, and was 13.0 and 7.3 μg·m(-3)·m(-2) leaf area in F. benghalensis. Gaseous toluene and xylene in a chamber were absorbed through leaf and transported via the stem, and finally reached to root zone, and also transported by direct diffusion from the air into the medium. Toluene and xylene transported via the stem was decreased with time after exposure. Xylene transported via the stem was higher than that by direct diffusion from the air into the medium over a 24-h period. The ratios of toluene transported via the stem versus direct diffusion from the air into the medium were 46.3 and 53.7% in S. actinophylla, and 46.9 and 53.1% in F. benghalensis, for an average of 47 and 53% for both species. The ratios of m,p-xylene transported over 3 to 9 h via the stem versus direct diffusion from the air into the medium was 58.5 and 41.5% in S. actinophylla, and 60.7 and 39.3% in F. benghalensis, for an average of 60 and 40% for both species, whereas the ratios of o-xylene transported via the stem versus direct diffusion from the air into the medium were 61 and 39%. Both S. actinophylla and F. benghalensis removed toluene and xylene from the air. The ratios of toluene and xylene transported from air to root zone via the stem were 47 and 60 %, respectively. This result suggests that root zone is a significant contributor to gaseous toluene and xylene removal, and transported via the stem plays an important role in this process.

Allowable stem nut wear and diagnostic monitoring for MOVs

International Nuclear Information System (INIS)

Swinburne, P.

1994-01-01

After a motor-operated valve (MOV) stem nut failure in 1991 that contributed to a forced plant shutdown, the FitzPatrick Plant staff developed criteria to check for excessive stem nut wear in MOVs. Allowable stem nut wear monitoring uses both direct dimensional measurement and diagnostic test data interpretation. The wear allowance is based on the recommended permitted backlash discussed in the Electric Power Research Institute/Nuclear Maintenance Assistance Center Technical Repair Guideline for the Limitorque SMB-000 Motor Actuator. The diagnostic analysis technique measures the time at zero load and compares this with a precalculated allowable zero force time. Excessive zero force time may be the result of other MOV problems, such as a loose stem nut lock nut or excessive free play in the drive sleeve bearing. Stress levels for new or nominal stem nuts and stem nuts with the full wear allowance were compared. Bending and shear stresses at the thread root increase for the maximum wear condition when compared with a open-quotes newclose quotes stem nut. These stresses are directly related to the thread root thickness. For typical MOV loading and common stem threading (with two diameters of thread engagement), the thread stresses are well within acceptable limits for ASTM B584-C86300 (formerly B147-863) manganese bronze (typical stem nut material)

Nitroaromatic detection and infrared communication from wild-type plants using plant nanobionics.

Science.gov (United States)

Wong, Min Hao; Giraldo, Juan P; Kwak, Seon-Yeong; Koman, Volodymyr B; Sinclair, Rosalie; Lew, Tedrick Thomas Salim; Bisker, Gili; Liu, Pingwei; Strano, Michael S

2017-02-01

Plant nanobionics aims to embed non-native functions to plants by interfacing them with specifically designed nanoparticles. Here, we demonstrate that living spinach plants (Spinacia oleracea) can be engineered to serve as self-powered pre-concentrators and autosamplers of analytes in ambient groundwater and as infrared communication platforms that can send information to a smartphone. The plants employ a pair of near-infrared fluorescent nanosensors-single-walled carbon nanotubes (SWCNTs) conjugated to the peptide Bombolitin II to recognize nitroaromatics via infrared fluorescent emission, and polyvinyl-alcohol functionalized SWCNTs that act as an invariant reference signal-embedded within the plant leaf mesophyll. As contaminant nitroaromatics are transported up the roots and stem into leaf tissues, they accumulate in the mesophyll, resulting in relative changes in emission intensity. The real-time monitoring of embedded SWCNT sensors also allows residence times in the roots, stems and leaves to be estimated, calculated to be 8.3 min (combined residence times of root and stem) and 1.9 min mm -1 leaf, respectively. These results demonstrate the ability of living, wild-type plants to function as chemical monitors of groundwater and communication devices to external electronics at standoff distances.

Combining -Omics to Unravel the Impact of Copper Nutrition on Alfalfa (Medicago sativa) Stem Metabolism.

Science.gov (United States)

Printz, Bruno; Guerriero, Gea; Sergeant, Kjell; Audinot, Jean-Nicolas; Guignard, Cédric; Renaut, Jenny; Lutts, Stanley; Hausman, Jean-Francois

2016-02-01

Copper can be found in the environment at concentrations ranging from a shortage up to the threshold of toxicity for plants, with optimal growth conditions situated in between. The plant stem plays a central role in transferring and distributing minerals, water and other solutes throughout the plant. In this study, alfalfa is exposed to different levels of copper availability, from deficiency to slight excess, and the impact on the metabolism of the stem is assessed by a non-targeted proteomics study and by the expression analysis of key genes controlling plant stem development. Under copper deficiency, the plant stem accumulates specific copper chaperones, the expression of genes involved in stem development is decreased and the concentrations of zinc and molybdenum are increased in comparison with the optimum copper level. At the optimal copper level, the expression of cell wall-related genes increases and proteins playing a role in cell wall deposition and in methionine metabolism accumulate, whereas copper excess imposes a reduction in the concentration of iron in the stem and a reduced abundance of ferritins. Secondary ion mass spectrometry (SIMS) analysis suggests a role for the apoplasm as a copper storage site in the case of copper toxicity. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists.

Leaf and stem morphoanatomy of Petiveria alliacea.

Science.gov (United States)

Duarte, M R; Lopes, J F

2005-12-01

Petiveria alliacea is a perennial herb native to the Amazonian region and used in traditional medicine for different purposes, such as diuretic, antispasmodic and anti-inflammatory. The morphoanatomical characterization of the leaf and stem was carried out, in order to contribute to the medicinal plant identification. The plant material was fixed, freehand sectioned and stained either with toluidine blue or astra blue and basic fuchsine. Microchemical tests were also applied. The leaf is simple, alternate and elliptic. The blade exhibits paracytic stomata on the abaxial side, non-glandular trichomes and dorsiventral mesophyll. The midrib is biconvex and the petiole is plain-convex, both traversed by collateral vascular bundles adjoined with sclerenchymatic caps. The stem, in incipient secondary growth, presents epidermis, angular collenchyma, starch sheath and collateral vascular organization. Several prisms of calcium oxalate are seen in the leaf and stem.

Photosynthesis and yield reductions from wheat stem sawfly (Hymenoptera: Cephidae): interactions with wheat solidness, water stress, and phosphorus deficiency.

Science.gov (United States)

Delaney, Kevin J; Weaver, David K; Peterson, Robert K D

2010-04-01

The impact of herbivory on plants is variable and influenced by several factors. The current study examined causes of variation in the impact of larval stem mining by the wheat stem sawfly, Cephus cinctus Norton (Hymenoptera: Cephidae), on spring wheat, Triticum aestivum L. We performed greenhouse experiments over 2 yr to (1) study whether biotic (hollow versus solid stemmed host wheat) and abiotic (water, phosphorus stress) factors interact with C. cinctus stem mining to influence degree of mined stem physiological (photosynthesis) and yield (grain weight) reductions; and (2) determine whether whole plant yield compensatory responses occur to offset stem-mining reductions. Flag leaf photosynthetic reduction was not detected 16-20 d after infestation, but were detected at 40-42 d and doubled from water or phosphorus stresses. Main stem grain weight decreased from 10 to 25% from stem mining, largely due to reductions in grain size, with greater reductions under low phosphorus and/or water levels. Phosphorus-deficient plants without water stress were most susceptible to C. cinctus, more than doubling the grain weight reduction due to larval feeding relative to other water and phosphorus treatments. Two solid stemmed varieties with stem mining had less grain weight loss than a hollow stemmed variety, so greater internal mechanical resistance may reduce larval stem mining and plant yield reductions. Our results emphasize the importance of sufficient water and macronutrients for plants grown in regions impacted by C. cinctus. Also, solid stemmed varieties not only reduce wheat lodging from C. cinctus, they may reduce harvested grain losses from infested stems.

Assessment of transformability of bacteria associated with tomato and potato plants

NARCIS (Netherlands)

Overbeek, van L.S.; Ray, J.L.; Elsas, van J.D.

2007-01-01

Transformation of plant-associated bacteria by plant DNA has never been demonstrated in agricultural fields. In total 552 bacterial isolates from stems of Ralstonia solanacearum-infected and healthy tomato plants and from stems and leaves of healthy potato plants were tested for natural genetic

Anti-inflammatory, antiallodynic effects and quantitative analysis of gallic acid in spray dried powders from Phyllanthus niruri leaves, stems, roots and whole plant

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Angélica G. Couto

2012-11-01

Full Text Available The anti-inflammatory and antiallodynic effects of spray dried powders starting from leaves, stems, roots, the mixture of leaves and stems, as well as the whole plant aqueous solutions of Phyllanthus niruri L., Phyllanthaceae, were assessed. Gallic acid, used as chemical marker, was quantified by HPLC in the spray dried powders. Carrageenan-induced inflammatory and allodynic responses in the mouse paw were used as pharmacological models. Quantitative and qualitative differences among chemical composition of different herb parts were observed. The oral administration of leaves or leaves plus stems spray dried powders (100 mg/kg significantly inhibited the carrageenan-induced allodynic effect (42±5 and 54±3%, respectively. Additionally, the spray dried powders of leaves significantly reduced carrageenan-induced paw oedema (35±6%. The spray dried powders of roots, stems, or the mixture of leaves, stems and roots (100 mg/kg, p.o. did not exhibit antiallodynic or antioedematogenic effect in the same model. In conclusion, differences in the chemical composition of spray dried powders from P. niruri are reflected in their in vivo pharmacological actions. Despite of a direct relationship of anti-inflammatory and antiallodynic effects with the gallic acid content had been observed, especially in the spray dried powders of leaves, the use of spray dried powders of leaves plus stems showed to be more effective, suggesting a synergic effect between their constituents.

Anti-inflammatory, antiallodynic effects and quantitative analysis of gallic acid in spray dried powders from Phyllanthus niruri leaves, stems, roots and whole plant

Directory of Open Access Journals (Sweden)

Angélica G. Couto

2013-02-01

Full Text Available The anti-inflammatory and antiallodynic effects of spray dried powders starting from leaves, stems, roots, the mixture of leaves and stems, as well as the whole plant aqueous solutions of Phyllanthus niruri L., Phyllanthaceae, were assessed. Gallic acid, used as chemical marker, was quantified by HPLC in the spray dried powders. Carrageenan-induced inflammatory and allodynic responses in the mouse paw were used as pharmacological models. Quantitative and qualitative differences among chemical composition of different herb parts were observed. The oral administration of leaves or leaves plus stems spray dried powders (100 mg/kg significantly inhibited the carrageenan-induced allodynic effect (42±5 and 54±3%, respectively. Additionally, the spray dried powders of leaves significantly reduced carrageenan-induced paw oedema (35±6%. The spray dried powders of roots, stems, or the mixture of leaves, stems and roots (100 mg/kg, p.o. did not exhibit antiallodynic or antioedematogenic effect in the same model. In conclusion, differences in the chemical composition of spray dried powders from P. niruri are reflected in their in vivo pharmacological actions. Despite of a direct relationship of anti-inflammatory and antiallodynic effects with the gallic acid content had been observed, especially in the spray dried powders of leaves, the use of spray dried powders of leaves plus stems showed to be more effective, suggesting a synergic effect between their constituents.

The stem factor challenge

International Nuclear Information System (INIS)

Russell, M.J.; Steele, R. Jr.; DeWall, K.G.; Watkins, J.C.; Bramwell, D.

1994-01-01

One of the most important challenges that still needs to be met in the effort to understand the operation of motor-operated, rising-stem valves is the ability to determine stem factor throughout the valve's load range. The stem factor represents the conversion of operator torque to stem thrust. Determining the stem factor is important because some motor-operated valves (MOVs) cannot be tested in the plant at design basis conditions. The ability of these valves to perform their design basis function (typically, to operate against specified flow and pressure loads) must be ensured by analytical methods or by extrapolating from the results of tests conducted at lower loads. Because the stem factor tends to vary in response to friction and lubrication phenomena that occur during loading and wedging, analytical methods and extrapolation methods have been difficult to develop and implement. Early investigations into variability in the stem factor tended to look only at the tip of the iceberg; they focused on what was happening at torque switch trip, which usually occurs at full wedging. In most stems, the stem factor is better (lower) in the wedging transient than before wedging, so working with torque switch trip data alone led many early researchers to false conclusions about the relationship between stem factor and load. However, research at the Idaho National Engineering Laboratory (INEL) has taken a closer look at what happens during the running portion of the closing stroke along with the wedging portion. This shift in focus is important, because functional failure of a valve typically consists of a failure to isolate flow, not a failure to achieve full wedging. Thus, the stem factor that must be determined for a valve's design basis closing requirements is the one that corresponds with the running load before wedging

Potato yield and quality as a function of the plant density

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Eero Varis

1975-05-01

Full Text Available The effects of potato plant density on yield quantity and quality were investigated at the Hankkija Plant Breeding Institute from 1971-73, using seed rates of 1600, 3200 and 4800 kg/ha, and seed sizes of 40, 80 and 120 g. The varieties used were Ijsselster and Record. The number of stems per m2 rose with increasing seed rate and with increasing seed size. Stem number increased with seed rate faster for small seed than for large. The response in stem number was greater for Ijsselster than for Record. The number of stems per seed tuber fell as the plant density rose. The number of tubers per m2 altered in the same direction as the number of stems, but less responsively. The reason for this was that the number of tubers per stem decreased with increasing plant density. The tuber yield showed a continual increase with increasing plant density. At the lowest stem densities (less than 20—25 stems/m2 small seed gave better results than other sizes, but at the higher plant densities, the importance of seed size faded away and the yield was dependant on the plant density alone. Net yield (gross yield 2 x seed rate, however, was higher the smaller the seed used, whatever the stem density. Tuber size decreased when plant density increased, the proportion of large tubers diminishing most, especially when small seed was used. The proportion of small tubers altered more for Ijsselster than for Record. Seed size and seed rate did not on average significantly affect the proportion of Class I potatoes, though small seed gave results slightly better than other sizes. The starch content of the yield rose when the seed rate was increased (16.0-16.3 -16.5 % and fell with increasing seed size (16.5 16.2 16.1 %. The maximum variation was 15.8-16.7 %. The specific gravity distribution improved with increasing plant density. Raw discolouration of the tubers did not alter significantly as the plant density rose. Blackening of the tubers decreased with increasing plant

Tradeoff between Stem Hydraulic Efficiency and Mechanical Strength Affects Leaf–Stem Allometry in 28 Ficus Tree Species

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Ze-Xin Fan

2017-09-01

Full Text Available Leaf–stem allometry is an important spectrum that linked to biomass allocation and life history strategy in plants, although the determinants and evolutionary significance of leaf–stem allometry remain poorly understood. Leaf and stem architectures – including stem area/mass, petiole area/mass, lamina area/mass, leaf number, specific leaf area (LA, and mass-based leafing intensity (LI – were measured on the current-year branches for 28 Ficus species growing in a common garden in SW China. The leaf anatomical traits, stem wood density (WD, and stem anatomical and mechanical properties of these species were also measured. We analyzed leaf–stem allometric relationships and their associations with stem hydraulic ad mechanical properties using species-level data and phylogenetically independent contrasts. We found isometric relationship between leaf lamina area/mass and stem area/mass, suggesting that the biomass allocation to leaf was independent to stem size. However, allometric relationship between LA/mass and petiole mass was found, indicating large leaves invest a higher fractional of biomass in petiole than small ones. LI, i.e., leaf numbers per unit of stem mass, was negatively related with leaf and stem size. Species with larger terminal branches tend to have larger vessels and theoretical hydraulic conductivity, but lower WD and mechanical strength. The size of leaf lamina, petiole, and stem was correlated positively with stem theoretical hydraulic conductivity, but negatively with stem WD and mechanical strength. Our results suggest that leaf–stem allometry in Ficus species was shaped by the trade-off between stem hydraulic efficiency and mechanical stability, supporting a functional interpretation of the relationship between leaf and stem dimensions.

Distribution of Tomato spotted wilt virus in dahlia plants.

Science.gov (United States)

Asano, S; Hirayama, Y; Matsushita, Y

2017-04-01

Tomato spotted wilt virus (TSWV) causes significant losses in the production of the ornamental plant Dahlia variabilis in Japan. The purpose of this study was to examine the distribution of TSWV in dahlia plants and identify plant parts that can be used in the selection of TSWV-free plants. The distribution of TSWV was investigated using reverse transcriptional polymerase chain reaction (RT-PCR) and tissue blot immunoassay. The detection rate of TSWV in latent infected compound leaves was the highest in the petiole, and it decreased from the veins and rachis to the lamina. The tissue blot immunoassays of the leaflets showed an uneven distribution of TSWV, especially along the edge of the leaf blade. In stems, the detection rate of TSWV was high partway up the stem compared to that in the upper and the lower parts of the stem during the vegetative growth stage. A highly uneven distribution was observed in the bulb. Our results indicated that middle parts of the stem as well as the petioles, rachis, and veins of compound leaves are suitable for detection of TSWV in dahlias. This study is the first to report uneven distribution of TSWV in dahlia plants. In this study, the distribution of Tomato spotted wilt virus (TSWV) in various parts of dahlia plants was investigated for the first time. The distribution of TSWV was uneven in compound leaves, leaflets, stems, and bulbs. The middle parts of the stem or the petiole and leaf veins should be sampled to detect TSWV when selecting healthy plants. © 2017 The Society for Applied Microbiology.

Variation in coumarin accumulation by stem age in Dendrobium ...

African Journals Online (AJOL)

In this study, laser scanning confocal microscopy was applied to determine the localization and relative quantity of coumarins in stems of Dendrobium thyrsiflorum Rchb. f. (Orchidaceae) when plants entered profuse flowering and initial fruit period during reproductive growth stage. Stems at the two growth stages were ...

Preliminary pharmacognostic screening of Achyranthes coynei stem

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Vinayak Upadhya

2015-01-01

Full Text Available Achyranthes coynei is a rare, endemic perennial shrub reported from Karnataka and Maharashtra states of India. The plant is used to treat various disorders by folk healers and was proven to have antimicrobial and antioxidant properties. The present study was undertaken to evaluate microscopic and macroscopic characters of A. coynei stem, along with its physicochemical parameters. ProgRes ® CapturePro and Microsoft Excel were used for statistical analysis. Perennial, shrubby nature and woody stem were the distinguishing morphological characters observed. Transverse section (TS illustrated quadrangular outline of the stem and showed the presence of two types of trichomes on the thick-walled epidermis. TS also showed number of rosette calcium oxalates crystals; prismatic and microsphenoid crystals; conjoint, collateral open secondary vascular bundles; and two amphixylic medullary bundles in the pith. Ash and extractive values, micro and macro elements and nutritive factors were estimated in the present study. The presence of alkaloids, saponins and triterpenoids were observed in preliminary phytochemical screening. High-performance thin layer chromatographic analysis yielded different bands and also indicated the presence of oleanolic acid. The studied parameters for A. coynei stem will be useful for identification and authentication of the plant material.

Preliminary pharmacognostic screening of Achyranthes coynei stem.

Science.gov (United States)

Upadhya, Vinayak; Ankad, Gireesh M; Pai, Sandeep R; Hegde, Shruti V; Hegde, Harsha V

2015-01-01

Achyranthes coynei is a rare, endemic perennial shrub reported from Karnataka and Maharashtra states of India. The plant is used to treat various disorders by folk healers and was proven to have antimicrobial and antioxidant properties. The present study was undertaken to evaluate microscopic and macroscopic characters of A. coynei stem, along with its physicochemical parameters. ProgRes(®) CapturePro and Microsoft Excel were used for statistical analysis. Perennial, shrubby nature and woody stem were the distinguishing morphological characters observed. Transverse section (TS) illustrated quadrangular outline of the stem and showed the presence of two types of trichomes on the thick-walled epidermis. TS also showed number of rosette calcium oxalates crystals; prismatic and microsphenoid crystals; conjoint, collateral open secondary vascular bundles; and two amphixylic medullary bundles in the pith. Ash and extractive values, micro and macro elements and nutritive factors were estimated in the present study. The presence of alkaloids, saponins and triterpenoids were observed in preliminary phytochemical screening. High-performance thin layer chromatographic analysis yielded different bands and also indicated the presence of oleanolic acid. The studied parameters for A. coynei stem will be useful for identification and authentication of the plant material.

Phytochemical screening and antimicrobial activity of roots, stem ...

African Journals Online (AJOL)

The roots, stem-bark and leaves of Grewia mollis which is used as herbal remedies for the cure of diarrhea and dysentery by natives in northern part of Nigeria were studied. The ethanol and water extracts of roots, stem-bark and leaves of the plant were subjected to phytochemical screening and antimicrobial activity against ...

CHEMICAL COMPOSITION AND NUTRITIVE VALUE OF MAIZE STEMS DEPENDING ON THE CUTTING HEIGHT OF PLANTS AT HARVEST

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Ireneus KOWALIK

2013-12-01

Full Text Available Studies were carried out in the two years in Trzcianka near Nowy Tomyśl, on brown soil, IIIa – IVa with pH 7.1 – 7.2. Plants of five maize cultivars were cut at the height of 15 cm and 55 cm. The lower parts of stems with leaves which remain on the field in case of high cutting, were characterized by a smaller content of protein and by a greater content of fibre, in comparison with the higher parts of plants. The energetic value of 1 kg of dry matter of the lower 40 cm part with leaves expressed in MJ NEL, in spite of significant differences in the chemical composition, was only insignificantly lower than the upper part. The content of dry matter, the chemical composition and the energetic value of both parts differed, depending on the cultivar.

Major Co-localized QTL for Plant Height, Branch Initiation Height, Stem Diameter, and Flowering Time in an Alien Introgression Derived Brassica napus DH Population

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Yusen Shen

2018-03-01

Full Text Available Plant height (PH, branch initiation height (BIH, and stem diameter (SD are three stem-related traits that play crucial roles in plant architecture and lodging resistance. Herein, we show one doubled haploid (DH population obtained from a cross between Y689 (one Capsella bursa-pastoris derived Brassica napus intertribal introgression and Westar (B. napus cultivar that these traits were significantly positively correlated with one another and with flowering time (FT. Based on a high-density SNP map, a total of 102 additive quantitative trait loci (QTL were identified across six environments. Seventy-two consensus QTL and 49 unique QTL were identified using a two-round strategy of QTL meta-analysis. Notably, a total of 19 major QTL, including 11 novel ones, were detected for these traits, which comprised two QTL clusters on chromosomes A02 and A07. Conditional QTL mapping was performed to preliminarily evaluate the genetic basis (pleiotropy or tight linkage of the co-localized QTL. In addition, QTL by environment interactions (QEI mapping was performed to verify the additive QTL and estimate the QEI effect. In the genomic regions of all major QTL, orthologs of the genes involved in phytohormone biosynthesis, phytohormone signaling, flower development, and cell differentiation in Arabidopsis were proposed as candidate genes. Of these, BnaA02g02560, an ortholog of Arabidopsis GASA4, was suggested as a candidate gene for PH, SD, and FT; and BnaA02g08490, an ortholog of Arabidopsis GNL, was associated with PH, BIH and FT. These results provide useful information for further genetic studies on stem-related traits and plant growth adaptation.

Effects of phyllotaxy on biomechanical properties of stems of Cercis occidentalis (Fabaceae).

Science.gov (United States)

Caringella, Marissa A; Bergman, Brett A; Stanfield, Ryan C; Ewers, Madeleine M; Bobich, Edward G; Ewers, Frank W

2014-01-01

Phyllotaxy, the arrangement of leaves on a stem, may impact the mechanical properties of woody stems several years after the leaves have been shed. We explored mechanical properties of a plant with alternate distichous phyllotaxy, with a row of leaves produced on each side of the stem, to determine whether the nodes behave as spring-like joints. Flexural stiffness of 1 cm diameter woody stems was measured in four directions with an Instron mechanical testing system; the xylem of the stems was then cut into node (former leaf junction) and nonnode segments for measurement of xylem density. Stems had 20% greater flexural stiffness in the plane perpendicular to the original leaf placement than in the parallel plane. The xylem in the node region was more flexible, but it had significantly greater tissue density than adjacent regions, contradicting the usual correlation between wood density and stiffness. Nodes can behave as spring-like joints in woody plants. For plagiotropic shoots, distichous phyllotaxy results in stems that resist up-and-down bending more than lateral back-and-forth movement. Thus, they may more effectively absorb applied loads from fruits, animals, wind, rain, and snow and resist stresses due to gravity without cracking and breaking. Under windy conditions, nodes may improve damping by absorbing vibrational energy and thus reducing oscillation damage. The effect of plant nodes also has biomimetic design implications for architects and material engineers.

An improved sensor for precision detection of in situ stem water content using a frequency domain fringing capacitor.

Science.gov (United States)

Zhou, Haiyang; Sun, Yurui; Tyree, Melvin T; Sheng, Wenyi; Cheng, Qiang; Xue, Xuzhang; Schumann, Henrik; Schulze Lammers, Peter

2015-04-01

One role of stems is that of water storage. The water content of stems increases and decreases as xylem water potential increases and decreases, respectively. Hence, a nondestructive method to measure stem water content (StWC) = (volume of water) : (volume of stem), could be useful in monitoring the drought stress status of plants. We introduce a frequency domain inner fringing capacitor-sensor for measuring StWC which operates at 100 MHz frequency. The capacitor-sensor consists of two wave guides (5-mm-wide braided metal) that snugly fit around the surface of a stem with a spacing of 4-5 mm between guides. Laboratory measurements on analog stems reveals that the DC signal output responds linearly to the relative dielectric constant of the analog stem, is most sensitive to water content between the waveguides to a depth of c. 3 mm from the stem surface, and calibrations based on the gravimetric water loss of excised stems of plants revealed a resolution in StWC of < ± 0.001 v/ v. The sensor performed very well on whole plants with a 100-fold increased resolution compared with previous frequency domain and time domain reflectometry methods and, hence, may be very useful for future research requiring nondestructive measurements of whole plants. © European Union 2014. New Phytologist © 2014 New Phytologist Trust.

Effects of gamma radiation on stem diameter growth, carbon gain and biomass partitioning in Helianthus annuus

International Nuclear Information System (INIS)

Thiede, M.E.; Link, S.O.; Fellows, R.J.; Beedlow, P.A.

1995-01-01

To determine the effects of gamma radiation on stem diameter growth, carbon gain, and biomass partitioning, 19-day-old dwarf sunflower plants (Helianthus annuus, variety NK894) were given variable doses (0–40 Gy) from a 60Co gamma source. Exposure of plants to gamma radiation caused a significant reduction in stem growth and root biomass. Doses as low as 5 Gy resulted in a significant increase in leaf density, suggesting that very low doses of radiation could induce morphological growth changes. Carbohydrate analysis of plants exposed to 40 Gy demonstrated significantly more starch content in leaves and significantly less in stems 18 days after exposure compared with control plants. In contrast, the carbohydrate content of the roots of plants exposed to 40 Gy was not significantly different from non-irradiated plants 18 days after exposure. (author)

Correlation between agronomic and stem borer resistant traits in ...

African Journals Online (AJOL)

GY had significant relationship with days to 50% pollen shed, (DTA) (rg = 0.49**), plant height (PH) (rg ... that either days to 50% pollen shed or plant height could be considered in selection for stem borer resistance. ... HOW TO USE AJOL.

Expressing OsMPK4 Impairs Plant Growth but Enhances the Resistance of Rice to the Striped Stem Borer Chilo suppressalis

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Xiaoli Liu

2018-04-01

Full Text Available Mitogen-activated protein kinases (MPKs play a central role not only in plant growth and development, but also in plant responses to abiotic and biotic stresses, including pathogens. Yet, their role in herbivore-induced plant defenses and their underlying mechanisms remain largely unknown. Here, we cloned a rice MPK gene, OsMPK4, whose expression was induced by mechanical wounding, infestation of the striped stem borer (SSB Chilo suppressalis, and treatment with jasmonic acid (JA, but not by treatment with salicylic acid (SA. The overexpression of OsMPK4 (oe-MPK4 enhanced constitutive and/or SSB-induced levels of JA, jasmonoyl-l-isoleucine (JA-Ile, ethylene (ET, and SA, as well as the activity of elicited trypsin proteinase inhibitors (TrypPIs, and reduced SSB performance. On the other hand, compared to wild-type plants, oe-MPK4 lines in the greenhouse showed growth retardation. These findings suggest that OsMPK4, by regulating JA-, ET-, and SA-mediated signaling pathways, functions as a positive regulator of rice resistance to the SSB and a negative regulator of rice growth.

Investigation of valve failure problems in LWR power plants

International Nuclear Information System (INIS)

1980-04-01

An analysis of component failures from information in the computerized Nuclear Safety Information Center (NSIC) data bank shows that for both PWR and BWR plants the component category most responsible for approximately 19.3% of light water reactor (LWR) power plant shutdowns. This investigation by Burns and Roe, Inc. shows that the greatest cause of shutdowns in LWRs due to valve failures is leakage from valve stem packing. Both BWR plants and PWR plants have stem leakage problems

Key factors to inoculate Botrytis cinerea in tomato plants

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Álefe Vitorino Borges

2014-09-01

Full Text Available Studies addressing the biological control of Botrytis cinerea have been unsuccessful because of fails in inoculating tomato plants with the pathogen. With the aim of establishing a methodology for inoculation into stems, experiments were designed to assess: i. the aggressiveness of pathogen isolates; ii. the age at which tomato plants should be inoculated; iii. the susceptibility of tissues at different stem heights; iv. the need for a moist chamber after inoculation; and v. the effectiveness of gelatin regarding inoculum adhesion. Infection with an isolate from tomato plants that was previously inoculated into petioles and then re-isolated was successful. An isolate from strawberry plants was also aggressive, although less than that from tomato plants. Tomato plants close to flowering, at 65 days after sowing, and younger, middle and apical stem portions were more susceptible. There was positive correlation between lesion length and sporulation and between lesion length and broken stems. Lesion length and the percentage of sporulation sites were reduced by using a moist chamber and were not affected by adding gelatin to the inoculum suspension. This methodology has been adopted in studies of B. cinerea in tomato plants showing reproducible results. The obtained results may assist researchers who study the gray mold.

stem rust seedling resistance genes in ethiopian wheat cultivars

African Journals Online (AJOL)

Prof. Adipala Ekwamu

Stem rust caused by Puccinia graminis f. sp. tritici is one of the major biotic limiting factors for wheat production in Ethiopia. Host plant resistance is the best option to manage stem rust from its economic and environmental points of view. Wheat cultivars are released for production without carrying race specific tests against ...

Tritium turnover in succulent plants

International Nuclear Information System (INIS)

Krishnamoorthy, T.M.; Gogate, S.S.; Soman, S.D.

1977-01-01

Measurements of turnover rates for tissue free water tritium (TFWT) and tissue bound tritium (TBT) were carried out in three succulent plants, Opuntia sp., E. Trigona and E. Mili using tritiated water as tracer. The estimated half-times were 52, 57.5 and 80 days for TFWT and 212, 318 and 132 days for TBT in the stems of the above plants respectively. Opuntia sp. showed significant incorporation of TBT, 10% of TFWT on weight basis, while the other two plants showed lesser incorporation, 2-3% of TFWT. However, the leaves of E. Mili indicated the same level of fixation of TBT as the stem of Opuntia sp. (author)

Output of continuous directed selection aimed at short stem development in Winter Rye (Secale cereale L.

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В. В. Скорик

2013-05-01

Full Text Available The article provides progress report on the barley of F3к-10029/Saratovske 4 height decreasing throughout 1974 to 2012 by way of selecting plants of the shortest stem. 38 years of selecting the shortest stem genotypes cut down plant height by 5,7 times at the background of dominant Hl gene expression. Average plant height during 38 breeding cycles was descending by 2,69 cm, but this was not an even trend. New creative donor for ultimate short stem characteristic, Gnome 3, has been developed, with Hl-3Hl-3alleles designation. Relative impact on the efficacy of minus-selection by the plant height of the selection differential (38,00% and inheritance coefficient in its narrow sense (14,56% is established. Efficiency of the selection is realized with the decrease of winter rye height plants by 72,08% as expected by the relative breeding forecast. Analyzes is completed for 11 genetic and statistical clusters of average utilitarian characteristics of Gnome 3 ultra short stem rye over the period from 1974 to 2012.

Average stem biomass of Gundelia ( Gundelia tournefortii L.) in ...

African Journals Online (AJOL)

We studied Gundelia tournefortii L. to determine its stem biomass characteristics. Data were collected with accidental sampling method (1*1 m) in this area. A total of 15 plots were collected and 75 samples were studied in this study. However, the minimum, maximum and mean stem biomass of this plant was 5.5, 22.6 and ...

Investigation of valve failure problems in LWR power plants

Energy Technology Data Exchange (ETDEWEB)

None

1980-04-01

An analysis of component failures from information in the computerized Nuclear Safety Information Center (NSIC) data bank shows that for both PWR and BWR plants the component category most responsible for approximately 19.3% of light water reactor (LWR) power plant shutdowns. This investigation by Burns and Roe, Inc. shows that the greatest cause of shutdowns in LWRs due to valve failures is leakage from valve stem packing. Both BWR plants and PWR plants have stem leakage problems (BWRs, 21% and PWRs, 34%).

Occurrence of blockage in cut stems of Clematis L.

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Agata Jędrzejuk

2013-04-01

Full Text Available During vase life of cut flowers obstructions in stem xylem vessels develop. Such obstructions may restrict water uptake in stems and its transport towards flowers, thus lowering their ornamental value and longevity. Clematis is a very attractive plant which can be used as a cut flower in floral compositions. However, nothing is known about the histochemical or cytolo- gical nature of xylem blockages occurring in cut stems of this plant. Observations carried out on Clematis cv. 'Solidarność' proved that tyloses appeared as a principal source of xylem blockage in cut stems. The preservative composed of 200 mg × dm-3 8-HQC (8-hydroxyquinolin citrate and 2% sucrose arre-sted development of xylem blockage, while the vessels in stems kept in water were filled with tyloses or an amorphic substance. PAS reaction proved that polysaccharides were present in the xylem occlusions, whereas no homogalacturonans were immunolocalized in tyloses using JIM 5 and JIM 7 antibodies. The present study provides new information on the origin of xylem occlusions in clematis and their development in two different vase solutions. Such information can be useful to develop pro- per postharvest treatments aiming to improve keeping qualities of this new cut flower.

Tolerance of combined submergence and salinity in the halophytic stem-succulent Tecticornia pergranulata

DEFF Research Database (Denmark)

Colmer, T D; Vos, H; Pedersen, Ole

2009-01-01

pergranulata subsp. pergranulata (syn. Halosarcia pergranulata subsp. pergranulata). Growth and total sugars in succulent stems were assessed as a function of time after submergence. Underwater net photosynthesis, dark respiration, total sugars, glycinebetaine, Na(+), Cl(-) and K(+), in succulent stems, were...... assessed in a NaCl dose-response experiment. KEY RESULTS: Submerged plants ceased to grow, and tissue sugars declined. Photosynthesis by succulent stems was reduced markedly when underwater, as compared with in air. Capacity for underwater net photosynthesis (P(N)) was not affected by 10-400 mM Na......Cl, but it was reduced by 30 % at 800 mM. Dark respiration, underwater, increased in succulent stems at 200-800 mM NaCl, as compared with those at 10 mM NaCl. On an ethanol-insoluble dry mass basis, K(+) concentration in succulent stems of submerged plants was equal to that in drained controls, across all Na...

Decoupled leaf and stem economics in rain forest trees

NARCIS (Netherlands)

Baraloto, C.; Paine, C.E.T.; Poorter, L.; Beauchene, J.; Bonal, D.; Domenach, A.M.; Herault, B.; Patiño, S.; Roggy, J.C.; Chave, J.

2010-01-01

Cross-species analyses of plant functional traits have shed light on factors contributing to differences in performance and distribution, but to date most studies have focused on either leaves or stems. We extend these tissue-specific analyses of functional strategy towards a whole-plant approach by

Yield, quality and longevity of stems of Photinia fraseri

Directory of Open Access Journals (Sweden)

Marlise Nara Ciotta

2012-06-01

Full Text Available The greens understand cutting the shoots of the plant without the flower, but with ornamental feature to the composition of arrangements. In Sierra of Santa Catarina a species that has emerged is the Photinia fraseri, known by the common name of fotinia, which features distinctive color of its leaves. The aim of this study was to assess the yield of stems and durability of this species in solutions containing sucrose and temperature. Were collected during two periods, 10 stems in each of the cutting heights (10, 30 and 50cm, classified by size, (CL1 greater than or equal to 60cm, (CL2 and between 60 and 45cm (CL3 less than 45cm and quantified. To test the durability stems greater than 60cm were subjected to aqueous solutions of 0, 5, 10, 15 and 20% sucrose for 24h at two temperatures and evaluated according to the stage of senescence (I, or II. The largest increase in number of stems at harvest was held in march in relation to november. The stems are longer, obtained after the long period of growth, harvest months of march and let the merchant handle best to use them in floral arrangements. This species has great potential in post-harvest, since the longevity of the stems with maintaining your ornamental quality is far superior to most plants grown as cut foliage.

Chemistry of plants which accumulate metals. [Hybanthus floribundus; Polycarpia glabra

Energy Technology Data Exchange (ETDEWEB)

Farago, M E; Clark, A J; Pitt, M J

1975-01-01

Information on the accumulation of metals in plants is reviewed. The authors report some of their investigations of the metal accumulating plants Hybanthus floribundus and Polycarpia glabra. In general, nickel levels in the aerial parts of plants are quite low, however a number of plants have been cited as nickel tolerant. The leaves of the Hybanthus plant have large epidermal cells and ridges of large cells which continue along the leaf stem and on to the main stem of the bush. It was found that nickel could be located in these large cells. The presence of nickel in the ridge cells was confirmed by an electron probe technique using a scanning electron microscope. These same areas showed high concentration of pectins. In studying the Polycarpia species, two zinc complexes were found to accumulate in the flowers and stems. 22 references.

Anatomy of leaf and stem of Erythrina velutina

Directory of Open Access Journals (Sweden)

Márcia M. B. da Silva

2013-04-01

Full Text Available Erythrina velutina Willd., Fabaceae, known as "mulungu", is a tree of tropical regions, as northeastern Brazil. Its bark is used in folk medicine as tranquilizer, sedative and insomnia. This study aimed to characterize the stem and leaf anatomy and to provide subsidies to quality control of the plant drug due to its wide use in folk medicine as well as its differentiation from other species with the same popular name. Samples were collected at Cuité, in Paraíba State, Brazil, fixed in FAA50, semipermanent slides were made, following usual procedures in plant anatomy. The stem shows a cylindrical contour, covered by a uniseriate epidermis covered by a thickened cuticle. It shows claviform glandular and branched trichomes with uniseriate stalk. Secretory cavities are into the phloem. The leaf epidermis has branched and glandular trichomes and anisocytic and paracytic stomata, on both sides, with predominance of branched trichomes and stomata on abaxial surface. Secretory cavities in stem and leaf, types of trichomes and stomata, its location and distribution constitute diagnostic characters for this specie. The structural characterization of the stem and leaf allows its distinction from other ones of this genus, ensuring safety for commercial pharmacological uses, allowing certification of the authenticity of raw material.

Anatomy of leaf and stem of Erythrina velutina

Directory of Open Access Journals (Sweden)

Márcia M. B. da Silva

2013-02-01

Full Text Available Erythrina velutina Willd., Fabaceae, known as "mulungu", is a tree of tropical regions, as northeastern Brazil. Its bark is used in folk medicine as tranquilizer, sedative and insomnia. This study aimed to characterize the stem and leaf anatomy and to provide subsidies to quality control of the plant drug due to its wide use in folk medicine as well as its differentiation from other species with the same popular name. Samples were collected at Cuité, in Paraíba State, Brazil, fixed in FAA50, semipermanent slides were made, following usual procedures in plant anatomy. The stem shows a cylindrical contour, covered by a uniseriate epidermis covered by a thickened cuticle. It shows claviform glandular and branched trichomes with uniseriate stalk. Secretory cavities are into the phloem. The leaf epidermis has branched and glandular trichomes and anisocytic and paracytic stomata, on both sides, with predominance of branched trichomes and stomata on abaxial surface. Secretory cavities in stem and leaf, types of trichomes and stomata, its location and distribution constitute diagnostic characters for this specie. The structural characterization of the stem and leaf allows its distinction from other ones of this genus, ensuring safety for commercial pharmacological uses, allowing certification of the authenticity of raw material.

Synthesis of silver nanoparticles from stem bark of Cochlospermum religiosum (L.) Alston: an important medicinal plant and evaluation of their antimicrobial efficacy

Science.gov (United States)

Sasikala, A.; Linga Rao, M.; Savithramma, N.; Prasad, T. N. V. K. V.

2015-10-01

The use of different parts of plants for the synthesis of nanoparticles is considered as a green technology as it does not involve any harmful chemicals. Herein, we report on rapid biosynthesis of silver nanoparticles (SNPs) from aqueous stem bark extract of Cochlospermum religiosum a medicinal plant. The reduced silver nanoparticles were characterized by using UV-Visible spectroscopy (UV-Vis), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis, atomic force microscopy, and Fourier transform infrared (FT-IR). The UV-Visible spectrum of the aqueous medium containing silver nanoparticles showed an absorption peak at around 445 nm, XRD showed that the particles are crystalline in nature, with a face-centered cubic structure and the SEM images showed that the spherical-shaped silver nanoparticles were observed and the size range was found to be 20-35 nm. FT-IR spectroscopy analysis revealed that carbohydrate, polyphenols, and protein molecules were involved in the synthesis and capping of silver nanoparticles. These phytosynthesized SNPs were tested for their antimicrobial activity and it analyzed by measuring the inhibitory zone. Cochlospermum religiosum aqueous stem bark extract of SNPs showed highest toxicity to Staphylococcus followed by Pseudomonas, Escherichia coli and Bacillus and lowest toxicity towards Proteus. Whereas in fungal species highest inhibition zone against Aspergillus flavus followed by Rhizopus, Fusarium, and Curvularia, and minimum inhibition zone was observed against Aspergillus niger species. The outcome of this study could be useful for the development of value added products from indigenous medicinal plants of India for nanotechnology-based biomedical applications.

Organizer-Derived WOX5 Signal Maintains Root Columella Stem Cells through Chromatin-Mediated Repression of CDF4 Expression.

NARCIS (Netherlands)

Pi, L.; Graaff, van der E.; Llavata Peris, C.I.; Weijers, D.; Henning, L.; Groot, de E.; Laux, T.

2015-01-01

Stem cells in plants and animals are maintained pluripotent by signals from adjacent niche cells. In plants, WUSCHEL HOMEOBOX (WOX) transcription factors are central regulators of stem cell maintenance in different meristem types, yet their molecular mode of action has remained elusive. Here we show

Plant and Floret Growth at Distinct Developmental Stages During the Stem Elongation Phase in Wheat

Directory of Open Access Journals (Sweden)

Zifeng Guo

2018-03-01

Full Text Available Floret development is critical for grain setting in wheat (Triticum aestivum, but more than 50% of grain yield potential (based on the maximum number of floret primordia is lost during the stem elongation phase (SEP, from the terminal spikelet stage to anthesis. Dynamic plant (e.g., leaf area, plant height and floret (e.g., anther and ovary size growth and its connection with grain yield traits (e.g., grain number and width are not clearly understood. In this study, for the first time, we dissected the SEP into seven stages to investigate plant (first experiment and floret (second experiment growth in greenhouse- and field-grown wheat. In the first experiment, the values of various plant growth trait indices at different stages were generally consistent between field and greenhouse and were independent of the environment. However, at specific stages, some traits significantly differed between the two environments. In the second experiment, phenotypic and genotypic similarity analysis revealed that grain number and size corresponded closely to ovary size at anthesis, suggesting that ovary size is strongly associated with grain number and size. Moreover, principal component analysis (PCA showed that the top six principal components PCs explained 99.13, 98.61, 98.41, 98.35, and 97.93% of the total phenotypic variation at the green anther, yellow anther, tipping, heading, and anthesis stages, respectively. The cumulative variance explained by the first PC decreased with floret growth, with the highest value detected at the green anther stage (88.8% and the lowest at the anthesis (50.09%. Finally, ovary size at anthesis was greater in wheat accessions with early release years than in accessions with late release years, and anther/ovary size shared closer connections with grain number/size traits at the late vs. early stages of floral development. Our findings shed light on the dynamic changes in plant and floret growth-related traits in wheat and the

Zingiber zerumbet flower stem postharvest characterization

Directory of Open Access Journals (Sweden)

Charleston Gonçalves

2017-05-01

Full Text Available About the Zingiber zerumbet little is known about its cut flower postharvest and market, despite its high ornamental potential. The inflorescences, which resemble a compact cone, emerge from the base of the plants and start with green color changing to red with the age. This study objective was to characterize floral stem of ornamental ginger in two cultivate conditions and to evaluate the longevity of those submitted to post-harvest treatments. Flower stems were harvest from clumps cultivated under full sun and partial shade area, and were submitted to the postharvest treatments: complete flower immersion in tap water (CFI or only the base stem immersion (BSI. The flower stems harvested from clumps at partial shade presented higher fresh weight, length and diameter of the inflorescences compared to flower stems harvested from clumps at full sun area. The flower stem bracts cultivated in full sun area changed the color from green to red 10.69 and 11.94 days after BSI and CFI postharvest treatments, and the vase life were 22.94 and 28.19 days, respectively. Flower stem harvest in partial shade area change the color only after 18.94 and 18.43 days and the vase life durability was 27.56 and 31.81, respectively. The complete immersion of the flower stem increase the vase life durability in 5.25 and 4.25 days compared to flowers kept with the stem base immersed only, in flower stems harvested from clumps cultivated in full sun area and partial shade area, respectively. Flower stems harvested from clumps cultivated in partial shade area and completely immerse in tap water during 3 hours increase the vase life durability in 8.87 days compared to flowers harvested from clumps cultivated in full sun area and base immersed only.

Following basal stem rot in young oil palm plantings.

Science.gov (United States)

Panchal, G; Bridge, P D

2005-01-01

The PCR primer GanET has previously been shown to be suitable for the specific amplification of DNA from Ganoderma boninense. A DNA extraction and PCR method has been developed that allows for the amplification of the G. boninense DNA from environmental samples of oil palm tissue. The GanET primer reaction was used in conjunction with a palm-sampling programme to investigate the possible infection of young palms through cut frond base surfaces. Ganoderma DNA was detected in frond base material at a greater frequency than would be expected by comparison with current infection levels. Comparisons are made between the height of the frond base infected, the number of frond bases infected, and subsequent development of basal stem rot. The preliminary results suggest that the development of basal stem rot may be more likely to occur when young lower frond bases are infected.

How to store plant tissues in the absence of liquid nitrogen? Ethanol preserves the RNA integrity of Cannabis sativa stem tissues

Directory of Open Access Journals (Sweden)

Lauralie Mangeot-Peter

2016-09-01

Full Text Available The preservation of intact RNA is a limiting step when gene expression profiling is performed using field-collected plant material. The use of liquid nitrogen ensures the optimal preservation of RNA, however it is not always practical, especially if the plant material has to be sampled in remote locations. Ethanol is known to preserve DNA in plant tissues even after a long storage period and here its suitability to preserve the RNA of textile hemp cortical tissues was tested. Hemp (Cannabis sativa L. is an economically important fibre crop because it supplies cellulosic bast fibres used in different industrial sectors. In this study we demonstrate the suitability of ethanol for RNA preservation by analyzing tissues stored at 4 °C for 1, 2, 4 and 8 days. We show that in all the cases the extracted RNA is intact. We finally analyze hemp stem tissues stored in ethanol for 1 month and demonstrate the preservation of the tissue structure, particularly of bast fibres.

SYNERGISTIC ANTIBACTERIAL EFFECT OF STEM BARK ...

African Journals Online (AJOL)

userpc

ABSTRACT. The study was aimed at screening the stem bark extracts of Faidherbia albida and Psidium guajava for synergistic antibacterial effect against methicillin resistant Staphylococcus aureus (MRSA). The powdered plant materials were extracted with methanol using cold maceration technique and the extracts were ...

Optical measurement of stem xylem vulnerability

OpenAIRE

Brodribb, Timothy J.; Carriqui, Marc; Delzon, Sylvain; Lucani, Christopher

2017-01-01

The vulnerability of plant water transport tissues to a loss of function by cavitation during water stress is a key indicator of the survival capabilities of plant species during drought. Quantifying this important metric has been greatly advanced by noninvasive techniques that allow embolisms to be viewed directly in the vascular system. Here, we present a new method for evaluating the spatial and temporal propagation of embolizing bubbles in the stem xylem during imposed water stress. We de...

Effect of plant-biostimulant on cassava initial growth

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João Emílio de Souza Magalhães

2016-04-01

Full Text Available ABSTRACT Biostimulants are complex substances that promote hormonal balance in plants, favor the genetic potential expression, and enhance growth of shoots and root system. The use of these plant growth promoters in crops can increase quantitatively and qualitatively crop production. Therefore, the aim of this study was to evaluate the effect of a commercial biostimulant on the initial growth of cassava. The experiment was arranged in a 2 x 5 factorial design, corresponding to two cassava cultivars (Cacau-UFV and Coimbra and five biostimulant concentrations (0, 4, 8, 12 and 16 mL L-1. At 90 days after planting, the characteristics leaf area, plant height, stem diameter, leaf number, total dry matter and dry matter of roots, stems and leaves were evaluated. The biostimulant promoted linear increases in plant height, leaf number, leaf area, total dry matter, dry matter of stems, leaves and roots. The cultivar Cacau-UFV had a higher growth rate than the cultivar Coimbra. The growth promoter stimulated the early growth of the cassava crop.

Interactions of Phytophthora capsici with Resistant and Susceptible Pepper Roots and Stems.

Science.gov (United States)

Dunn, Amara R; Smart, Christine D

2015-10-01

Using host resistance is an important strategy for managing pepper root and crown rot caused by Phytophthora capsici. An isolate of P. capsici constitutively expressing a gene for green fluorescent protein was used to investigate pathogen interactions with roots, crowns, and stems of Phytophthora-susceptible bell pepper 'Red Knight', Phytophthora-resistant bell pepper 'Paladin', and Phytophthora-resistant landrace Criollos de Morelos 334 (CM-334). In this study, the same number of zoospores attached to and germinated on roots of all cultivars 30 and 120 min postinoculation (pi), respectively. At 3 days pi, significantly more secondary roots had necrotic lesions on Red Knight than on Paladin and CM-334 plants. By 4 days pi, necrotic lesions had formed on the taproot of Red Knight but not Paladin or CM-334 plants. Although hyphae were visible in the crowns and stems of all Red Knight plants observed at 4 days pi, hyphae were observed in crowns of only a few Paladin and in no CM-334 plants, and never in stems of either resistant cultivar at 4 days pi. These results improve our understanding of how P. capsici infects plants and may contribute to the use of resistant pepper cultivars for disease management and the development of new cultivars.

Different parts, different stories: climate sensitivity of growth is stronger in root collars vs. stems in tundra shrubs.

Science.gov (United States)

Ropars, Pascale; Angers-Blondin, Sandra; Gagnon, Marianne; Myers-Smith, Isla H; Lévesque, Esther; Boudreau, Stéphane

2017-08-01

Shrub densification has been widely reported across the circumpolar arctic and subarctic biomes in recent years. Long-term analyses based on dendrochronological techniques applied to shrubs have linked this phenomenon to climate change. However, the multi-stemmed structure of shrubs makes them difficult to sample and therefore leads to non-uniform sampling protocols among shrub ecologists, who will favor either root collars or stems to conduct dendrochronological analyses. Through a comparative study of the use of root collars and stems of Betula glandulosa, a common North American shrub species, we evaluated the relative sensitivity of each plant part to climate variables and assessed whether this sensitivity is consistent across three different types of environments in northwestern Québec, Canada (terrace, hilltop and snowbed). We found that root collars had greater sensitivity to climate than stems and that these differences were maintained across the three types of environments. Growth at the root collar was best explained by spring precipitation and summer temperature, whereas stem growth showed weak and inconsistent responses to climate variables. Moreover, sensitivity to climate was not consistent among plant parts, as individuals having climate-sensitive root collars did not tend to have climate-sensitive stems. These differences in sensitivity of shrub parts to climate highlight the complexity of resource allocation in multi-stemmed plants. Whereas stem initiation and growth are driven by microenvironmental variables such as light availability and competition, root collars integrate the growth of all plant parts instead, rendering them less affected by mechanisms such as competition and more responsive to signals of global change. Although further investigations are required to determine the degree to which these findings are generalizable across the tundra biome, our results indicate that consistency and caution in the choice of plant parts are a key

Piper nigrum Leaf and Stem Assisted Green Synthesis of Silver Nanoparticles and Evaluation of Its Antibacterial Activity Against Agricultural Plant Pathogens

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Kanniah Paulkumar

2014-01-01

Full Text Available Utilization of biological materials in synthesis of nanoparticles is one of the hottest topics in modern nanoscience and nanotechnology. In the present investigation, the silver nanoparticles were synthesized by using the leaf and stem extract of Piper nigrum. The synthesized nanoparticle was characterized by UV-vis spectroscopy, X-ray diffraction (XRD, scanning electron microscope (SEM, transmission electron microscope (TEM, energy dispersive X-ray analysis (EDAX, and Fourier Transform Infrared Spectroscopy (FTIR. The observation of the peak at 460 nm in the UV-vis spectra for leaf- and stem-synthesized silver nanoparticles reveals the reduction of silver metal ions into silver nanoparticles. Further, XRD analysis has been carried out to confirm the crystalline nature of the synthesized silver nanoparticles. The TEM images show that the leaf- and stem-synthesized silver nanoparticles were within the size of about 7–50 nm and 9–30 nm, respectively. The FTIR analysis was performed to identify the possible functional groups involved in the synthesis of silver nanoparticles. Further, the antibacterial activity of the green-synthesized silver nanoparticles was examined against agricultural plant pathogens. The antibacterial property of silver nanoparticles is a beneficial application in the field of agricultural nanotechnology.

Valve-stem-packing improvement study. Final report

International Nuclear Information System (INIS)

Adey, C.W.; Klein, J.J.

1982-08-01

By employing questionnaires and face-to-face interviews with valve and valve packing manufacturers, as well as nuclear plant personnel, an understanding of valve stem packing leakage problems from each of the three viewpoints was developed. This information, in-house experience, and available technical literature were used to develop specific recommendations for valve manufacturers, valve packing manufacturers, and nuclear plant valve users. It was generally recommended that each these groups make better use of graphite packing. The questionnaires and interviews indicated that increased usage of graphite packing over the last few years has reduced the incidence of valve packing problems. To confirm this, a survey of Licensee Event Reports (LERs) from 1972 to 1980 was undertaken using the keywords Valve and Packing. A statistical analysis of the LER data confirms that the adoption of graphite packing has significantly reduced valve stem leakage

METHYL JASMONATE AND STEM BENDING HARDENING AND INITIAL GROWTH OF Cordia trichotoma SEEDLINGS

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Danielle Acco Cadorin

2015-12-01

Full Text Available The submission of seedlings to mechanical stimuli and plant growth regulator promote their hardening and can be included in the routine of nurseries, favoring the survival and initial growth in the field. The study aimed to evaluate the effects of applying methyl jasmonate and stem bending in hardening and initial growth of Cordia trichotoma seedlings. Seedlings were subjected to 20 stem bending daily for 4 weeks; 20 stem bending daily for 8 weeks; 50 µmol.L-1 of methyl jasmonate applied weekly for 4 weeks; 50 µmol.L-1 of methyl jasmonate applied weekly for 8 weeks and the control treatment. The design was a completely randomized, with five repetitions of the fourteen seedlings. Seedlings submitted to hardening treatments showed less increment in height, greater increment in stem diameter and less value for strength index. Seedlings of control treatment had greater loss of root tissue electrolytes and less potential for root regeneration. In the field, 180 days after planting, seedlings submitted to eight weeks of stem bending and eight methyl jasmonate applications showed greater increment in height and stem diameter. The results indicate that both stem bending such as methyl jasmonate application for eight weeks are effective in promoting hardening and improve the starting performance in field of Cordia trichotoma seedlings.

Expression of genes associated with carbohydrate metabolism in cotton stems and roots

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Scheffler Jodi

2009-01-01

Full Text Available Abstract Background Cotton (Gossypium hirsutum L is an important crop worldwide that provides fiber for the textile industry. Cotton is a perennial plant that stores starch in stems and roots to provide carbohydrates for growth in subsequent seasons. Domesticated cotton makes these reserves available to developing seeds which impacts seed yield. The goals of these analyses were to identify genes and physiological pathways that establish cotton stems and roots as physiological sinks and investigate the role these pathways play in cotton development during seed set. Results Analysis of field-grown cotton plants indicated that starch levels peaked about the time of first anthesis and then declined similar to reports in greenhouse-grown cotton plants. Starch accumulated along the length of the stem and the shape and size of the starch grains from stems were easily distinguished from transient starch. Microarray analyses compared gene expression in tissues containing low levels of starch with tissues rapidly accumulating starch. Statistical analysis of differentially expressed genes indicated increased expression among genes associated with starch synthesis, starch degradation, hexose metabolism, raffinose synthesis and trehalose synthesis. The anticipated changes in these sugars were largely confirmed by measuring soluble sugars in selected tissues. Conclusion In domesticated cotton starch stored prior to flowering was available to support seed production. Starch accumulation observed in young field-grown plants was not observed in greenhouse grown plants. A suite of genes associated with starch biosynthesis was identified. The pathway for starch utilization after flowering was associated with an increase in expression of a glucan water dikinase gene as has been implicated in utilization of transient starch. Changes in raffinose levels and levels of expression of genes controlling trehalose and raffinose biosynthesis were also observed in vegetative

Distribution and utilization of 15N in cowpeas injected into the stem under influence of water deficit.

Science.gov (United States)

Götz K-P; Herzog, H

2000-01-01

Investigations were carried out on Vigna unguiculata L. Walp. to estimate the distribution and utilization of 15N in different organs after stem injection during vegetative, flowering and pod filling stage. During flowering effects of water deficit were also examined. In well watered plants, within 4 days after injection, 65% of 15N accumulated in leaves. This was drastically reduced to 42% by water deficit. 15N accumulation in stems increased under water deficit. The translocation of 15N from the stem base to roots were not altered by water deficit. During pod filling 62% of recovered 15N in the plants had accumulated in seeds, 24% in leaves and 11% in stems within 4 days, whereas the uptake of nitrogen in pod walls and roots remained low (2%). These results demonstrate that the method of injecting very small quantities (1 mg/plant) of 15N into the stem base allows an exact and detailed quantitative assessment of N translocation/distribution with regard to different organs, different growth stages and different treatments.

Agronomic characters and lodging resistance of plant height mutants of rice

International Nuclear Information System (INIS)

Zhang Zhonggui; Wu Yuejin; Liu Binmei; Xu Xue; Zhang Lili; Wang Min

2010-01-01

Fourteen plant height mutants of Nipponbare were used to study the effect of plant height on the agronomic characters and lodging resistance. The results indicated that the plant height was positively correlated with spike length, third internode length, height of gravity center, fresh weight of main stem, dry weight of main stem, thousand-grain weight, grain-yield per plant and biological yield, and the second internode length. Meanwhile, plant height played an important role in lodging resistance, it was significantly positively correlated with lodging index and negatively correlated with bending moment and culm type index. The correlation between agronomic characters and lodging resistance showed that several agronomic characters had strong impact on the lodging resistance, such as spike length, height of gravity center, basal internode length ( first and second internode), fresh and dry weight of main stem, dry weight of basal internode, seed setting, thousand-grain weight, grain-weight per plant and biological yield. (authors)

Effect of Fusarium isolates and their filtrates on respiratory rate and chemical analysis of squash plants.

Science.gov (United States)

El-Shenawy, Z; Mansour, M A; El-Behrawi, S

1978-01-01

The highly pathogenic isolate stimulated the emergence of the squash seedlings first, caused, however, the highest death rate of the seedlings finally. Fusarium isolates and their culture filtrates inhibited the respiratory rate of squash plants significantly. However, F. oxysporum isolates inhibited respiration more than F. solani isolates. Seasonal changes of respiration decline show that the respiratory rate decreased with plant growth in the case of infested soil and of plants injected with culture filtrates. However, spraying Fusarium culture filtrates on the foliage gave opposite results when the plants grew older. Fusarium solani isolates decreased nitrogen content of squash stems and leaves, while F. oxysporum isolates gave reverse results. Injecting Fusarium culture filtrate into the plant decreased nitrogen content of both stems and leaves, while spraying the foliage with the filtrates increased nitrogen content more than that of the control. Phosphorus content of the stems of squash plants, sown in infested soil, was less than in the control when the plants were treated with F. solani and higher when they were treated with F. oxysporum isolates. On the other hand, the phosphorus content of squash leaves was higher than in the control. In the case of injected plants, however, the phosphorus content in stems and leaves was equal to that of the control or less, and with sprayed plants it was higher than in the control. Infesting the soil with Fusarium isolates and spraying the foliage with their culture filtrates increased potassium content of squash stems and leaves, while injecting the filtrates into the plants decreased potassium content of both stems and leaves.

Teaching STEM through Horticulture: Implementing an Edible Plant Curriculum at a STEM-Centric Elementary School

Science.gov (United States)

Graves, Leila A.; Hughes, Harrison; Balgopal, Meena M.

2016-01-01

School gardens are ideal places for students to ask and answer questions about science. This paper describes a case study of two 3rd grade teachers and two STEM coordinators who were recruited to implement and evaluate a horticultural-based curriculum developed for this study. Informed by the Teacher-Centered Systemic Reform model we conducted a…

Maize yield and quality in response to plant density and application of a novel plant growth regulator

NARCIS (Netherlands)

Zhang, Q.; Zhang, L.; Evers, J.B.; Werf, van der W.; Zhang, W.; Duan, L.

2014-01-01

Farmers in China have gradually increased plant density in maize to achieve higher yields, but this has increased risk of lodging due to taller and weaker stems at higher plant densities. Plant growth regulators can be used to reduce lodging risk. In this study, for the first time, the performance

Quantitative Variation of Flavonoids and Diterpenes in Leaves and Stems of Cistus ladanifer L. at Different Ages

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Cristina Valares Masa

2016-02-01

Full Text Available The compounds derived from secondary metabolism in plants perform a variety of ecological functions, providing the plant with resistance to biotic and abiotic factors. The basal levels of these metabolites for each organ, tissue or cell type depend on the development stage of the plant and they may be modified as a response to biotic and/or abiotic stress. As a consequence, the resistance state of a plant may vary in space and time. The secondary metabolites of Cistus ladanifer have been quantified in leaves and stems throughout autumn, winter, spring and summer, and at different ages of the plant. This study shows that there are significant differences between young leaves, mature leaves and stems, and between individuals of different ages. Young leaves show significantly greater synthesis of flavonoids and diterpenes than mature leaves and stems, with a clear seasonal variation, and the differences between leaves at different growth stages and stems is maintained during the quantified seasons. With respect to age, specimens under one year of age secreted significantly lower amounts of compounds. The variation in the composition of secondary metabolites between different parts of the plant, the season and the variations in age may determine the interactions of Cistus ladanifer with the biotic and abiotic factors to which it is exposed.

Controls on tree species stem transport and emission of methane from tropical peatlands

Science.gov (United States)

Van Haren, J. L. M.; Cadillo-Quiroz, H.

2016-12-01

Methane emissions from wetlands dominate the global budget and are most likely responsible for the annual variability in emissions. Methane is produced and consumed by microbial activity and then transported to the atmosphere. Plants have been shown to facilitate the transport of methane to significant amounts, but broad surveys across multiple sites have been lacking. We present data collected from multiple peatland and wetland sites south of Iquitos Peru and varzea sites from Santarem Brazil and compare our results to the limited literature of tree stem fluxes. The survey suggests that methane stem emissions might be conserved at the genera level, but not the family level. Large emitters exist in the Aracaceae, Euphorbiaceae, and Sapotaceae, however, other genera within the same families do not emit any methane. Certain genera are consistent pan-tropical methane emitters. The methane emission from the stems decreases generally with height, suggesting a diffusion constrained stem flux. Further constraints on the methane emissions from tree stems involve soil methane concentration and wood density, which is likely an indicator for stem conductivity. Diurnal cycles, flooding level and tree leaves appear to have less of an influence on the tree methane emissions though flooding can lead to a translocation of emissions up the stem to above the flooding level. Methane emissions and the plant transport pathways appear to be constrained at the genera level within wetlands.

Acetylcholinesterase and butyrylcholinesterase inhibitory activity of some selected Nigerian medicinal plants

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Taiwo O. Elufioye

Full Text Available Plants have been found to be useful as memory enhansers as well as antiaging. Twenty two of such plants from sixteen families were investigated for their acetylcholinesterase (AChE and butyrylcholinesterase (BuChE inhibitory activities using the in vitro Ellman's spectrophotometric and in situ bioautographic methods with physostigmine as standard. At least three morphological parts were examined for each of the plants investigated and the test concentration was 42.5 µg/ mL. Some plants were active on both enzymes though with some morphological parts being more active than others. The root bark of Spondias mombin showed the highest activity to the two enzymes; 64.77% and 83.94% on AChE and BuChE respectively. Other plant parts of the selected plants exhibited some remarkable selectivity in their actions. Those selectively active against AChE were Alchornia laxiflora stem bark (41.12% and root bark, Callophyllum inophyllurn root bark (56.52%. The leaves of C. jagus (74.25%, Morinda lucida leaves (40.15%, Peltophorum pterocarpum leaves and stem bark (49.5% and 68.85%, respectively, physiostigmine gave 90.31% inhibition. Generally higher activities were found against BuChE. Bombax bromoposenze leaves, root bark and stem bark were particularly active. The inhibition was over 80%. Other selective plant parts are the leaves Antiaris africana, Cissampelos owarensis aerial parts (78.96%, Combretum molle leaves and stem bark (90.42% and 88.13%, respectively, Dioscorea dumentorum root bark and tuber (over 87%, G. kola leaves, Markhamia tomentosa root bark, Pycnanthus angolensis stem bark and Tetrapleura tetraptera leaves. Most of these plants are taken as food or are food ingredients in Nigeria and may account for the low incidence of Alzheimer's disease in the country and may play certain roles in the mediation of the disease.

Esau's Plant anatomy: meristems, cells, and tissues of the plant body : their structure, function, and development

National Research Council Canada - National Science Library

Evert, Ray Franklin; Esau, Katherine; Eichhorn, Susan E

2006-01-01

... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The Body of a Vascular Plant Is Composed of Three Tissue Systems . . . . . . . . . . . . . . . . . . . . . Structurally Stem, Leaf, and Root Differ Primarily...

Drying characteristics of willow chips and stems

NARCIS (Netherlands)

Gigler, J.K.; Loon, van W.K.P.; Seres, I.; Meerdink, G.; Coumans, W.J.

2000-01-01

In supply chains of willow (Salix viminalis) biomass to energy plants, drying is advisable in order to enable safe long-term storage, increase boiler efficiency and reduce gaseous emissions. To gain insight into the drying process, drying characteristics of willow chips and stems were investigated

Hygienic quality of stem fractions of mechanically processed fibre hemp and linseed

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H-R. KYMÄLÄINEN

2008-12-01

Full Text Available Bast fibre is the most important fraction of bast fibre plants for technical products, i.e. thermal insulations and packaging materials. The hygienic quality of the various fractions of bast fibre plants is of interest in thermal insulations, because it may affect the quality of indoor air. Packaging materials may be associated e.g. with foodstuffs, which highlights the importance of hygienic quality. The aim of this study was to screen the hygienic quality, determined as microbial content, of mechanically fractionated fibre hemp and linseed plants harvested in the autumn before frost, after early frost and in spring. In addition, the possible correlation between microbes and ash was investigated. Two plant species, fibre hemp and linseed were studied. The plants were cultivated in Siuntio in southern Finland during the years 2002 and 2003, harvested in autumn or in spring and mechanically fractionated. The microbial contents of the fractions were examined by measuring the total number of microbes using Hygicult® growing slides. The microbial content of fractions of fibre hemp and linseed varied between 103 and 109 cfu/gdw. The fibre of hemp harvested after early frost or in spring had the lowest amount of moulds, but during winter and spring the amounts of bacteria and yeasts increased in hemp. Mechanically separated fibre and shive contained less microbes than the stalk. Ash contents of all examined samples of stems and stem fractions varied between 1% and 14%. The fibre after fractionating had a lower ash content (2.3–3.3% than that of stems (4.4–6.9% harvested in the autumn. The ash content of stem and shive decreased to 1.6% during winter, the ash content of fibre being even somewhat lower (0.9%. No correlation was observed between the contents of microbes and ash.;

Numerical Modeling for the Solute Uptake from Groundwater by Plants-Plant Uptake Package

OpenAIRE

El-Sayed, Amr A.

2006-01-01

A numerical model is presented to describe solute transport in groundwater coupled to sorption by plant roots, translocation into plant stems, and finally evapotranspiration. The conceptual model takes into account both Root Concentration Factor, RCF, and Transpiration Stream Concentration Factor, TSCF for chemicals which are a function of Kow. A similar technique used to simulate the solute transport in groundwater to simulate sorption and plant uptake is used. The mathematical equation is s...

Digitization and Visualization of Greenhouse Tomato Plants in Indoor Environments

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Dawei Li

2015-02-01

Full Text Available This paper is concerned with the digitization and visualization of potted greenhouse tomato plants in indoor environments. For the digitization, an inexpensive and efficient commercial stereo sensor—a Microsoft Kinect—is used to separate visual information about tomato plants from background. Based on the Kinect, a 4-step approach that can automatically detect and segment stems of tomato plants is proposed, including acquisition and preprocessing of image data, detection of stem segments, removing false detections and automatic segmentation of stem segments. Correctly segmented texture samples including stems and leaves are then stored in a texture database for further usage. Two types of tomato plants—the cherry tomato variety and the ordinary variety are studied in this paper. The stem detection accuracy (under a simulated greenhouse environment for the cherry tomato variety is 98.4% at a true positive rate of 78.0%, whereas the detection accuracy for the ordinary variety is 94.5% at a true positive of 72.5%. In visualization, we combine L-system theory and digitized tomato organ texture data to build realistic 3D virtual tomato plant models that are capable of exhibiting various structures and poses in real time. In particular, we also simulate the growth process on virtual tomato plants by exerting controls on two L-systems via parameters concerning the age and the form of lateral branches. This research may provide useful visual cues for improving intelligent greenhouse control systems and meanwhile may facilitate research on artificial organisms.

Lower Permian stems as fluvial paleocurrent indicators of the Parnaíba Basin, northern Brazil

Science.gov (United States)

Capretz, Robson Louiz; Rohn, Rosemarie

2013-08-01

A comprehensive biostratinomic study was carried out with abundant stems from the Lower Permian Motuca Formation of the intracratonic Parnaíba Basin, central-north Brazil. The fossils represent a rare tropical to subtropical paleofloristic record in north Gondwana. Tree ferns dominate the assemblages (mainly Tietea, secondarily Psaronius), followed by gymnosperms, sphenophytes, other ferns and rare lycophytes. They are silica-permineralized, commonly reach 4 m length (exceptionally more than 10 m), lie loosely on the ground or are embedded in the original sandstone or siltstone matrix, and attract particular attention because of their frequent parallel attitudes. Many tree fern stems present the original straight cylindrical to slightly conical forms, other are somewhat flattened, and the gymnosperm stems are usually more irregular. Measurements of stem orientations and dimensions were made in three sites approximately aligned in a W-E direction in a distance of 27.3 km at the conservation unit "Tocantins Fossil Trees Natural Monument". In the eastern site, rose diagrams for 54 stems indicate a relatively narrow azimuthal range to SE. These stems commonly present attached basal bulbous root mantles and thin cylindrical sandstone envelopes, which sometimes hold, almost adjacent to the lateral stem surface, permineralized fern pinnae and other small plant fragments. In the more central site, 82 measured stems are preferentially oriented in the SW-NE direction, the proportion of gymnosperms is higher and cross-stratification sets of sandstones indicate paleocurrents mainly to NE and secondarily to SE. In the western site, most of the 42 measured stems lie in E-W positions. The predominantly sandy succession, where the fossil stems are best represented, evidences a braided fluvial system under semiarid conditions. The low plant diversity, some xeromorphic features and the supposedly almost syndepositional silica impregnation of the plants are coherent with marked dry

Numerical relationships of the Solidago altissima stem gall insect-parasitoid guild food chain.

Science.gov (United States)

Abrahamson, Warren G; Armbruster, Paulette O; Maddox, G David

1983-06-01

The field site conditions (soil pH, soil moisture, soil nutrient availability, etc.) and abundances of Solidago altissima (often included in S. canadensis sensu lato), three S. altissima specific stem gall formers, and the parasitepredator guilds for two of the three gall insects were investigated. It was found that S. altissima is tolerant of a wide range of site conditions. Herbivore (stem gall insects) occurrences were positively correlated with plant occurrence, in a linear fashion. However, there was no disproportionate increase in stem gall insect densities with plant density as might be predicted by the resource concentration hypothesis. Parasitoid guilds were exploiting stem gall insect populations over a wide range of occurrence, but were under-utilizing fields of higher herbivore occurrences. Path analysis showed a high degree of predictability in the causal models, with all but 14% of the ball gall parasitoid guild and all but 43% of the elliptical gall parasitoid guild occurrences explained by the direct influences of stem gall insect occurrence and the indirect influences of goldenrod occurrence and site conditions. The numerical relations of this three trophic level system suggest a well-integrated and well-controlled food chain.

Key factors to inoculate Botrytis cinerea in tomato plants

OpenAIRE

Borges,Álefe Vitorino; Saraiva,Rodrigo Moreira; Maffia,Luiz Antonio

2014-01-01

Studies addressing the biological control of Botrytis cinerea have been unsuccessful because of fails in inoculating tomato plants with the pathogen. With the aim of establishing a methodology for inoculation into stems, experiments were designed to assess: i. the aggressiveness of pathogen isolates; ii. the age at which tomato plants should be inoculated; iii. the susceptibility of tissues at different stem heights; iv. the need for a moist chamber after inoculation; and v. the effectiveness...

Antioxidant activity of mulberry stem extract: A potential used as supplement for oxidative stress-related diseases

Directory of Open Access Journals (Sweden)

Phi Phuong Pham

2017-06-01

Full Text Available Overproduction of reactive oxygen species is involved in many diseases, including cardiovascular, neurodegenerative diseases, diabetes, cancer, viral and bacterial infections as well as osteoarthritis. Although antioxidant activity of Morus alba L. has been investigated in various parts of this plant, a little attention has been paid to the stems of this plant. Therefore, the present study was designed to systematically investigate the antioxidant activity of M. alba stem extract using various in vitro antioxidant assay systems. The present data showed that the stem extract of M. alba exhibited a hydrogen-donating ability, an ability to quench hydroxyl radicals, having superoxide and nitric oxide scavenging activity as well as iron reducing capacity. This study highlights the potential of this plant for further development as a natural source of antioxidant or as an alternative treatment for oxidative stress-related diseases.

Gnom 3 as a Donor for Ultra Short- Stem Trait of Winter Rye

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В. В. Скорик

2011-05-01

Full Text Available The article reflects the progress of genetic decrease of Rye F 3k- 10029/ Saratovske (Саратовське 4 height by means of the shortest stem plants selection during the period from 1974 to 2010. 37 years selection of the shortest- stern genotypes decreased the plants height from 119.33 cm to 22.57cm. Targeted selection into minus direction decreased the plants height in 5,29 times on the background of the dominant HI expression. In average, the height of plants in the course of 27 breeding cycles were decreasing by 2.69 cm, but that was not going gradually. A new donor Gnom 3 had been created for ultra short-stem trait of the Winter Rye, with the marking of alleles HI-3HI-3. Relative influence on the minus selection efficiency has been established by height of plants for the selection differential (38% and coefficient of inheritance in narrow sense (14,56%. Realized efficiency of selection in decrease of winter rye height in 72,08% of cases corresponded to predicted hit ration of the breeding. Analyzes of genetic and statistical parameters and correlation clusters of 11 utilitarian average characteristics of ultra short- stem rye Gnom 3 for the period of 1974 to 2010 has been performed.

CHANGES OF SUCROSE CONTENT AND INVERTASE ACTIVITY DURING SUGARCANE STEM STORAGE

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Tri Agus Siswoyo

2016-10-01

Full Text Available Invertases (beta-D-fructofuranosidase, E.C. 3.2.1.26 are the key enzymes involved in sucrose metabolism in sugarcane plants. They are highly correlated with sucrose and reducing sugar contents during plant growth. The sugarcane plants have two kinds of invertases, namely neutral invertase (NI and acid invertase (AI. They have different function in sucrose accumulation. The research aimed to study the role of AI and NI in accumulation of reducing sugar during storage of sugarcane stems. Plant materials of 18-month-old field grown sugarcane of the commercial variety R-579 (wet-land and M 442-51 (dry-land were used. Three internodes were sampled to represent immature (internode 1-8/F1, maturing (internode 9-16/F2, and mature (internode 17-24/F3 stem tissues. All tissues were stored for 0-9 days at room temperature (28-32oC and each day, the samplewas extracted to determine invertase activity, total soluble protein, and sugar contents. This observation was valid for invertase activity expressed on a protein basis. At the initiateharvested (0-3 days, NI had a higher specific activity than AI in the sucrose-accumulating region of the sugarcane stems. Negative significant correlation was found between NI specific activity and sucrose accumulation (r2 = 0.41, P < 0.05. AI showed a higher specific activity after 4 days harvested and had negative correlation with sucrose accumulation (r2 = 0.40, P < 0.05. These results showed that NI could be more  responsible in sucrose hydrolisis than AI at early storage of sugarcane stems.

The cost of myrmecophytism: insights from allometry of stem secondary growth.

Science.gov (United States)

Blatrix, Rumsaïs; Renard, Delphine; Djieto-Lordon, Champlain; McKey, Doyle

2012-10-01

Plant defence traits against herbivores incur production costs that are usually difficult to measure. However, estimating these costs is a prerequisite for characterizing the plant defence strategy as a whole. Myrmecophytes are plants that provide symbiotic ants with specialized nesting cavities, called domatia, in exchange for protection against herbivores. In the particular case of stem domatia, production of extra wood seems to be the only associated cost, making this indirect defence trait a particularly suitable model for estimating the cost of defence. Measurements were made of growth pattern and cumulative production cost of domatia over secondary growth in the myrmecophyte Leonardoxa africana subsp. africana, whose internodes display both a solid basal segment and a hollow distal part (the domatium), thus allowing paired comparison of investment in wood. Previous studies showed that 'overconstruction' of the hollow part of internodes during primary growth is needed for mechanical support. In this study, it is shown that the relationship between the woody cross-sectional area of the solid and hollow parts of internodes is negatively allometric at the beginning of secondary growth and nearly isometric later on. Thus, in hollow stems, the first phase of slow secondary growth compensates for the 'overconstruction' of the ring of wood during primary growth. Moreover, the cumulative production cost of a domatium (estimated as the additional volume of wood required for a hollow stem compared with a solid one) is very high at the beginning of secondary growth and then quickly tends to zero. Making domatia incurs high costs early in ontogeny, costs that are then amortized later in development of stems and of individual plants. Characterizing ontogenetic variation of the net cost of this peculiar defence mechanism will help us build more accurate theoretical models of resource allocation in myrmecophytes.

Plant Guide: Limestone hawksbeard: Crepis intermedia

Science.gov (United States)

L. St. John; D. Tilley

2012-01-01

Sunflower family (Asteraceae). Limestone hawksbeard is a native perennial forb with one or two stems arising from a taproot. Plants are 30-70cm tall and basal leaves are 10-40 cm long, pinnatifid, with a fairly broad, undivided midstrip and entire or dentate segments. Plants are densely or sparsely gray-tomentulose. There are 10-60 heads per plant that are 7-12...

Phytochemical screening and antibacterial evaluation of stem bark ...

African Journals Online (AJOL)

SERVER

2007-07-04

Jul 4, 2007 ... Mallotus philippinensis var. Tomentosus is a medicinal plant, which was tested against Escherichia coli,. Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella typhi and Bacillus subtilis. Phytochemi- cal screening of the stem bark of M. philippinensis indicates the presence of secondary ...

The biochemical basis of plant development

NARCIS (Netherlands)

Weijers, D.

2013-01-01

Plants develop highly elaborate structures, ranging from small mosses to large trees. All these structures are made by stem cells and consist of a few basic types of tissue. The field of Biochemistry of Plant Development studies the mechanisms by which regulatory proteins control the formation of

Branch Development of Five-Year-Old Betula alnoides Plantations in Response to Planting Density

Directory of Open Access Journals (Sweden)

Chun-Sheng Wang

2018-01-01

Full Text Available Branch development in the lower part of stem is critical to both early stem growth and wood quality of the most valuable section of tree, and its regulation through planting density has always been greatly concerned. Here the effect of planting density on branch development was examined in a five-year-old plantation of Betula alnoides with six planting densities (625, 833, 1111, 1250, 1667, and 2500 stems per hectare (sph in Guangdong Province, South China. Branch quantity (number, proportion, and density, morphology (diameter, length, and angle, position (height and orientation, and branch status (dead or alive were investigated for 54 dominant or co-dominant trees under six treatments of planting density after the growth of each tree was measured. Factors influencing branch development were also explored by mixed modelling. The results showed that the mean tree heights of 1250 and 1667 sph treatments were higher than those of other planting density treatments. The quantity of live branches decreased with increasing planting density. However, planting density had no significant effect on the number of all branches, and there existed no remarkable difference in branch number and proportion among four orientations. As for branch morphology, only the largest branch diameter had a significantly negative correlation with planting density. In addition, high planting density significantly increased the height of the largest branch within the crown. Mixed effects models indicated that branch diameter, length, and angle were closely correlated with each other, and they were all in positively significant correlation to the branch height at the stem section below six meters. It was concluded that properly increasing planting density will promote natural pruning, improve early branch control, and be beneficial for wood production from the most valuable section of the stem.

Early steps of adventitious rooting: morphology, hormonal profiling and carbohydrate turnover in carnation stem cuttings.

Science.gov (United States)

Agulló-Antón, María Ángeles; Ferrández-Ayela, Almudena; Fernández-García, Nieves; Nicolás, Carlos; Albacete, Alfonso; Pérez-Alfocea, Francisco; Sánchez-Bravo, José; Pérez-Pérez, José Manuel; Acosta, Manuel

2014-03-01

The rooting of stem cuttings is a common vegetative propagation practice in many ornamental species. A detailed analysis of the morphological changes occurring in the basal region of cultivated carnation cuttings during the early stages of adventitious rooting was carried out and the physiological modifications induced by exogenous auxin application were studied. To this end, the endogenous concentrations of five major classes of plant hormones [auxin, cytokinin (CK), abscisic acid, salicylic acid (SA) and jasmonic acid] and the ethylene precursor 1-aminocyclopropane-1-carboxylic acid were analyzed at the base of stem cuttings and at different stages of adventitious root formation. We found that the stimulus triggering the initiation of adventitious root formation occurred during the first hours after their excision from the donor plant, due to the breakdown of the vascular continuum that induces auxin accumulation near the wounding. Although this stimulus was independent of exogenously applied auxin, it was observed that the auxin treatment accelerated cell division in the cambium and increased the sucrolytic activities at the base of the stem, both of which contributed to the establishment of the new root primordia at the stem base. Further, several genes involved in auxin transport were upregulated in the stem base either with or without auxin application, while endogenous CK and SA concentrations were specially affected by exogenous auxin application. Taken together our results indicate significant crosstalk between auxin levels, stress hormone homeostasis and sugar availability in the base of the stem cuttings in carnation during the initial steps of adventitious rooting. © 2013 Scandinavian Plant Physiology Society.

Co-regulation of water and K(+) transport in sunflower plants during water stress recovery.

Science.gov (United States)

Benlloch, Manuel; Benlloch-González, María

2016-06-01

16-day-old sunflower (Helianthus annuus L.) plants were subjected to deficit irrigation for 12 days. Following this period, plants were rehydrated for 2 days to study plant responses to post-stress recovery. The moderate water stress treatment applied reduced growth in all plant organs and the accumulation of K(+) in the shoot. After the rehydration period, the stem recovered its growth and reached a similar length to the control, an effect which was not observed in either root or leaves. Moreover, plant rehydration after water stress favored the accumulation of K(+) in the apical zone of the stem and expanding leaves. In the roots of plants under water stress, watering to field capacity, once the plants were de- topped, rapidly favored K(+) and water transport in the excised roots. This quick and short-lived response was not observed in roots of plants recovered from water stress for 2 days. These results suggest that the recovery of plant growth after water stress is related to coordinated water and K(+) transport from the root to the apical zone of the ​​stem and expanding leaves. This stimulation of K(+) transport in the root and its accumulation in the cells of the growing zones of the ​​stem must be one of the first responses induced in the plant during water stress recovery. Copyright © 2016 Elsevier GmbH. All rights reserved.

Spatial and temporal analysis of stem bleeding disease in coconut palm in the state of sergipe, Brazil

Directory of Open Access Journals (Sweden)

REJANE R. DA COSTA E CARVALHO

2013-10-01

Full Text Available ABSTRACT Stem bleeding disease (resinosis of coconut palm is caused by Thielaviopsis paradoxa and is very important in the state of Sergipe, Brazil. Understanding the epidemiological behavior of the disease is essential for establishing more efficient control strategies. Thus, we characterized the temporal progression and spatial distribution of stem bleeding in a commercial orchard under conditions of natural infection in the area of Neopolis, Sergipe. Three plots with 729 plants each were selected and evaluated every two months for stem bleeding incidence. In the temporal analysis, the monomolecular model gave the best fit to data on disease incidence, as it accurately showed the temporal dynamics of the disease during the experiment period. The spatial pattern of stem bleeding varied over time, with initial infections presenting random pattern and then evolving to aggregate pattern during evaluations. This indicates that the disease may have originated from the pathogen survival structures, followed by auto infections caused by dissemination from plant to plant, either by humans, by contact between roots, or by the vector Rhynchophorus palmarum.

TOPOISOMERASE1α Acts through Two Distinct Mechanisms to Regulate Stele and Columella Stem Cell Maintenance.

Science.gov (United States)

Zhang, Yonghong; Zheng, Lanlan; Hong, Jing Han; Gong, Ximing; Zhou, Chun; Pérez-Pérez, José Manuel; Xu, Jian

2016-05-01

TOPOISOMERASE1 (TOP1), which releases DNA torsional stress generated during replication through its DNA relaxation activity, plays vital roles in animal and plant development. In Arabidopsis (Arabidopsis thaliana), TOP1 is encoded by two paralogous genes (TOP1α and TOP1β), of which TOP1α displays specific developmental functions that are critical for the maintenance of shoot and floral stem cells. Here, we show that maintenance of two different populations of root stem cells is also dependent on TOP1α-specific developmental functions, which are exerted through two distinct novel mechanisms. In the proximal root meristem, the DNA relaxation activity of TOP1α is critical to ensure genome integrity and survival of stele stem cells (SSCs). Loss of TOP1α function triggers DNA double-strand breaks in S-phase SSCs and results in their death, which can be partially reversed by the replenishment of SSCs mediated by ETHYLENE RESPONSE FACTOR115 In the quiescent center and root cap meristem, TOP1α is epistatic to RETINOBLASTOMA-RELATED (RBR) in the maintenance of undifferentiated state and the number of columella stem cells (CSCs). Loss of TOP1α function in either wild-type or RBR RNAi plants leads to differentiation of CSCs, whereas overexpression of TOP1α mimics and further enhances the effect of RBR reduction that increases the number of CSCs Taken together, these findings provide important mechanistic insights into understanding stem cell maintenance in plants. © 2016 American Society of Plant Biologists. All Rights Reserved.

Environmental stresses of field growth allow cinnamyl alcohol dehydrogenase-deficient Nicotiana attenuata plants to compensate for their structural deficiencies.

Science.gov (United States)

Kaur, Harleen; Shaker, Kamel; Heinzel, Nicolas; Ralph, John; Gális, Ivan; Baldwin, Ian T

2012-08-01

The organized lignocellulosic assemblies of cell walls provide the structural integrity required for the large statures of terrestrial plants. Silencing two CINNAMYL ALCOHOL DEHYDROGENASE (CAD) genes in Nicotiana attenuata produced plants (ir-CAD) with thin, red-pigmented stems, low CAD and sinapyl alcohol dehydrogenase activity, low lignin contents, and rubbery, structurally unstable stems when grown in the glasshouse (GH). However, when planted into their native desert habitat, ir-CAD plants produced robust stems that survived wind storms as well as the wild-type plants. Despite efficient silencing of NaCAD transcripts and enzymatic activity, field-grown ir-CAD plants had delayed and restricted spread of red stem pigmentation, a color change reflecting blocked lignification by CAD silencing, and attained wild-type-comparable total lignin contents. The rubbery GH phenotype was largely restored when field-grown ir-CAD plants were protected from wind, herbivore attack, and ultraviolet B exposure and grown in restricted rooting volumes; conversely, it was lost when ir-CAD plants were experimentally exposed to wind, ultraviolet B, and grown in large pots in growth chambers. Transcript and liquid chromatography-electrospray ionization-time-of-flight analysis revealed that these environmental stresses enhanced the accumulation of various phenylpropanoids in stems of field-grown plants; gas chromatography-mass spectrometry and nuclear magnetic resonance analysis revealed that the lignin of field-grown ir-CAD plants had GH-grown comparable levels of sinapaldehyde and syringaldehyde cross-linked into their lignins. Additionally, field-grown ir-CAD plants had short, thick stems with normal xylem element traits, which collectively enabled field-grown ir-CAD plants to compensate for the structural deficiencies associated with CAD silencing. Environmental stresses play an essential role in regulating lignin biosynthesis in lignin-deficient plants.

Effects of Inflorescence Stem Structure and Cell Wall Components on the Mechanical Strength of Inflorescence Stem in Herbaceous Peony

Directory of Open Access Journals (Sweden)

Qingping Geng

2012-04-01

Full Text Available Herbaceous peony (Paeonia lactiflora Pall. is a traditional famous flower, but its poor inflorescence stem quality seriously constrains the development of the cut flower. Mechanical strength is an important characteristic of stems, which not only affects plant lodging, but also plays an important role in stem bend or break. In this paper, the mechanical strength, morphological indices and microstructure of P. lactiflora development inflorescence stems were measured and observed. The results showed that the mechanical strength of inflorescence stems gradually increased, and that the diameter of inflorescence stem was a direct indicator in estimating mechanical strength. Simultaneously, with the development of inflorescence stem, the number of vascular bundles increased, the vascular bundle was arranged more densely, the sclerenchyma cell wall thickened, and the proportion of vascular bundle and pith also increased. On this basis, cellulose and lignin contents were determined, PlCesA3, PlCesA6 and PlCCoAOMT were isolated and their expression patterns were examined including PlPAL. The results showed that cellulose was not strictly correlated with the mechanical strength of inflorescence stem, and lignin had a significant impact on it. In addition, PlCesA3 and PlCesA6 were not key members in cellulose synthesis of P. lactiflora and their functions were also different, but PlPAL and PlCCoAOMT regulated the lignin synthesis of P. lactiflora. These data indicated that PlPAL and PlCCoAOMT could be applied to improve the mechanical strength of P. lactiflora inflorescence stem in genetic engineering.

The anti-diarrhoeal activity of the aqueous stem bark extract of ...

African Journals Online (AJOL)

The study aimed at evaluating the anti-diarrhoeal activity of the stem bark of the plant. The plant was extracted using distilled water (AEPF) and tested at 100 and 200 mg/kg doses on castor oil induced diarrhoea, castor oil induced enteropooling, small intestinal transit and magnesium sulphate induced diarrhoea in both rats ...

Sediment Supply as a Control on Plant-Morphodynamic Interactions

Science.gov (United States)

Manners, R.; Wilcox, A. C.; Kui, L.; Stella, J. C.; Lightbody, A.; Sklar, L. S.

2014-12-01

The caliber and quantity of sediment delivered to a channel influences its size and shape, yet we know little about how the sediment supply affects rivers whose geomorphic form is influenced by riparian vegetation. We present results from flume experiments that test the impact of sediment supply on plant-morphodynamic interactions. We introduced two sediment supply conditions to a 28-meter long, sand bedded flume (60 cm wide and 71 cm deep) at the UC-Berkeley Richmond Field Station: equilibrium (balance between sediment transport and supply) and deficit (transport exceeds sediment supply). We conducted ten runs with different riparian seedling configurations (individual plants or patches) and species (tamarisk or cottonwood), and stem and leaf density (0.003-0.47 cm2/cm2), under both sediment supply conditions. Plant species, size, and configuration were important in predicting the topographic adjustments that occurred during our experiments. These influences may be attributed to differences in plant morphology; tamarisk is shrubby while cottonwood is more tree-like, with a single stem and leaves concentrated higher on the plant. The plant-morphodynamic relationship, however, differed for the two sediment supply conditions. During sediment equilibrium, only patches of cottonwood served as sediment sinks compared to an unvegetated bed, but tamarisk patches had no impact on the sediment mass balance. During sediment deficit, in contrast, tamarisk patches accumulated more sediment than unvegetated beds. Stem and leaf density also controlled changes in bed elevation. During equilibrium conditions, increasing the density of cottonwood stems and leaves resulted in greater bed degradation. Conversely, aggradation occurred with increases in the density of tamarisk. For sediment deficit conditions, the relationship between stem and leaf density and the rate of bed change was negative for both species (i.e., higher density resulted in faster rate of scour). The shifting

Single-cell telomere-length quantification couples telomere length to meristem activity and stem cell development in Arabidopsis.

Science.gov (United States)

González-García, Mary-Paz; Pavelescu, Irina; Canela, Andrés; Sevillano, Xavier; Leehy, Katherine A; Nelson, Andrew D L; Ibañes, Marta; Shippen, Dorothy E; Blasco, Maria A; Caño-Delgado, Ana I

2015-05-12

Telomeres are specialized nucleoprotein caps that protect chromosome ends assuring cell division. Single-cell telomere quantification in animals established a critical role for telomerase in stem cells, yet, in plants, telomere-length quantification has been reported only at the organ level. Here, a quantitative analysis of telomere length of single cells in Arabidopsis root apex uncovered a heterogeneous telomere-length distribution of different cell lineages showing the longest telomeres at the stem cells. The defects in meristem and stem cell renewal observed in tert mutants demonstrate that telomere lengthening by TERT sets a replicative limit in the root meristem. Conversely, the long telomeres of the columella cells and the premature stem cell differentiation plt1,2 mutants suggest that differentiation can prevent telomere erosion. Overall, our results indicate that telomere dynamics are coupled to meristem activity and continuous growth, disclosing a critical association between telomere length, stem cell function, and the extended lifespan of plants. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Electronic plants

Science.gov (United States)

Stavrinidou, Eleni; Gabrielsson, Roger; Gomez, Eliot; Crispin, Xavier; Nilsson, Ove; Simon, Daniel T.; Berggren, Magnus

2015-01-01

The roots, stems, leaves, and vascular circuitry of higher plants are responsible for conveying the chemical signals that regulate growth and functions. From a certain perspective, these features are analogous to the contacts, interconnections, devices, and wires of discrete and integrated electronic circuits. Although many attempts have been made to augment plant function with electroactive materials, plants’ “circuitry” has never been directly merged with electronics. We report analog and digital organic electronic circuits and devices manufactured in living plants. The four key components of a circuit have been achieved using the xylem, leaves, veins, and signals of the plant as the template and integral part of the circuit elements and functions. With integrated and distributed electronics in plants, one can envisage a range of applications including precision recording and regulation of physiology, energy harvesting from photosynthesis, and alternatives to genetic modification for plant optimization. PMID:26702448

Evaluation of a redesigned 3/4-inch uranium hexafluoride cylinder valve stem

International Nuclear Information System (INIS)

Zonner, L.A.; Wamsley, S.D.

1978-01-01

The performance of a redesigned 3/4-in. uranium hexafluoride cylinder valve stem has been evaluated at the Portsmouth Gaseous Diffusion Plant. Prototypes, machined from Monel bar stock and having a 45 0 tip angle instead of the 15 0 tip angle of the standard valve stem, were fabricated. Tests included: cyclic leak evaluation; flow restriction determination; wear testing with uranyl fluoride deposits in the valve seat; stress corrosion testing; field testing (in previously rejected valve bodies); and production leak testing. Because their overall test performance was excellent, actual production usage of the redesigned stems was initiated. The in-service performance of valves fitted with redesigned stems has been significantly superior to that of valves having the standard stems: rejection rates have been 0.7 and 16.6 percent, respectively. Recommendations are made to replace all 15 0 angle tip stems presently in service with new stems having a 45 0 angle tip and to specify the new stem tip design for future 3/4-in. valve purchases

Organic fertilization in cherry tomato plants

Directory of Open Access Journals (Sweden)

Janini Tatiane Lima Souza Maia

2013-03-01

Full Text Available Cherry tomato (Solanum lycopersicum is highly demanding with regard to mineral nutrients. The use of animal manure shows to be an efficient and sustainable fertilization way for this crop. This study aimed to evaluate the effect of different doses of cattle manure in the vegetative and reproductive growth of cherry tomato. The experiment was conducted in a greenhouse at the Plant Science Department of Universidade Federal de Vicosa, using a completely randomized experimental design with 5 treatments and 4 replications, besides 1 control treatment using chemical fertilizer as a source of NPK. After 45 days from the beginning of the experiment, the number of leaves, flowers, and fruits, the dry mass of leaves, stem, flowers, fruits, and roots, the stem length, and the root volume were evaluated. The nutrient content in leaves, stem, and roots was also evaluated. Plants grown with chemical fertilizer obtained a lower average for all phytotechnical variables analyzed. The number of leaves and fruits, and the production of dry matter of leaves, fruits, and stems showed an upward linear response with an increase in manure doses. The Ca, Mg, and S leaf contents were higher in the treatment with chemical fertilization.

Biomass of tree species as a response to planting density and interspecific competition

Directory of Open Access Journals (Sweden)

Paulo Sérgio Lima e Silva

2014-04-01

Full Text Available Planting trees is an important way to promote the recovery of degraded areas in the Caatinga region. Experiments (E1, E2, and E3 were conducted in a randomized blocks design, with three, three, and five replicates, respectively. The objectives were to evaluate biomass of the shoots of: a gliricidia (G and sabiá (S, as a response to planting density; b G, S, and neem (N in competition; c G, and S in agroforestry. E1 was conducted in split-plots, and planting densities (400, 600, 800, 1000, and 1200 plants ha-1 as subplots. E2 consisted of a factorial comprising the following plots: GGG, NGN, SGS, NNN, GNG, SNS, SSS, GSG, NSN (each letter represents a row of plants. E3 was conducted with G and S in agroforestry experiment. The trees were harvested after 54, 42, and 27 months old, in E1, E2 and E3, respectively. In E1, G presented higher green biomass of the stems and leaf at smaller densities than S, but lower green biomass of branches at most densities. The species did not differ for mean stem dry biomass and leaf dry biomass, but G showed higher branch dry biomass at most densities. Higher planting densities increased green and dry biomass of stems, branches, and leaves in S, but decreased those characteristics in G, with the exception of leaf dry mass, which was not influenced by density. In E2, the behavior of each species was identical in plots containing the same or different species. Griricidia showed the highest green biomass of stems and branches, and the highest values for geren biomass of the leaf were observed for gliricidia and neem. The highest stem, branch, and leaf dry biomass values were obtained for G, S, and N, respectively. In E3, G was superior for stem and leaf green biomass, and for stem and branch dry biomass. There were no differences between species for the other biomass values.

Within-plant distribution of Aulacorthum solani (Hemiptera: Aphididae), on various greenhouse plants with implications for control.

Science.gov (United States)

Jandricic, S E; Mattson, N S; Wraight, S P; Sanderson, J P

2014-04-01

Foxglove aphid, Aulacorthum solani (Kaltenbach) (Hemiptera: Aphididae), has recently undergone a status change from an occasional pest to a serious pest in greenhouses of North America and the United Kingdom. Little nonanecdotal information exists on the ecology of this insect in greenhouse crops. To help improve integrated pest management decisions for A. solani, the within-plant distribution of this pest was explored on a variety of common greenhouse plants in both the vegetative and flowering stage. This aphid generally was found on lower leaves of vegetative plants, but was found higher in the canopy on reproductive plants (on flowers, flower buds, or upper leaves). Aphid numbers were not consistently positively correlated with total leaf surface areas within plant strata across plant species. Thus, the observed differences in preferred feeding sites on vegetative versus flowering plants are possibly a response to differences in nutritional quality of the various host-plant tissues. Despite being anecdotally described as a "stem-feeding aphid," A. solani was rarely found feeding on stems at the population densities established in our tests, with the exception of racemes of scarlet sage (Salvia splendans). Although some previous reports suggested that A. solani prefers to feed on new growth of plants, our results indicate that mature leaves are preferred over growing tips and young leaves. The implications of the within-plant feeding preferences of A. solani populations with respect to both biological and chemical control are discussed.

Efficacy of the stem powder of an invasive alien plant, Chromolaena ...

African Journals Online (AJOL)

ADOWIE PERE

2018-03-15

Mar 15, 2018 ... insecticidal activities of C. odorata stem powder and further suggests its usage as an ... insecticides in the management of C. maculatus infestation in Nigeria and elsewhere. ..... efficacy of neem (Azadirachta indica), false.

Stem juice production of the C4 sugarcane (Saccharum officinarum) is enhanced by growth at double-ambient CO2 and high temperature.

Science.gov (United States)

Vu, Joseph C V; Allen, Leon H

2009-07-15

Two cultivars of sugarcane (Saccharum officinarum cv. CP73-1547 and CP88-1508) were grown for 3 months in paired-companion, temperature-gradient, sunlit greenhouses under daytime [CO2] of 360 (ambient) and 720 (double ambient) micromol mol(-1) and at temperatures of 1.5 degrees C (near ambient) and 6.0 degrees C higher than outside ambient temperature. Leaf area and biomass, stem biomass and juice and CO2 exchange rate (CER) and activities of ribulose bisphosphate carboxylase-oxygenase (Rubisco) and phosphoenolpyruvate carboxylase (PEPC) of fully developed leaves were measured at harvest. On a main stem basis, leaf area, leaf dry weight, stem dry weight and stem juice volume were increased by growth at doubled [CO2] or high temperature. Such increases were even greater under combination of doubled [CO2]/high temperature. Plants grown at doubled [CO2]/high temperature combination averaged 50%, 26%, 84% and 124% greater in leaf area, leaf dry weight, stem dry weight and stem juice volume, respectively, compared with plants grown at ambient [CO2]/near-ambient temperature combination. In addition, plants grown at doubled [CO2]/high temperature combination were 2-3-fold higher in stem soluble solids than those at ambient [CO2]/near-ambient temperature combination. Although midday CER of fully developed leaves was not affected by doubled [CO2] or high temperature, plants grown at doubled [CO2] were 41-43% less in leaf stomatal conductance and 69-79% greater in leaf water-use efficiency, compared with plants grown at ambient [CO2]. Activity of PEPC was down-regulated 23-32% at doubled [CO2], while high temperature did not have a significant impact on this enzyme. Activity of Rubisco was not affected by growth at doubled [CO2], but was reduced 15-28% at high temperature. The increases in stem juice production and stem juice soluble solids concentration for sugarcane grown at doubled [CO2] or high temperature, or at doubled [CO2]/high temperature combination, were partially

Arbuscular Mycorrhizal Fungi Increase the Phenolic Compounds Concentration in the Bark of the Stem of Libidibia Ferrea in Field Conditions.

Science.gov (United States)

Dos Santos, Emanuela Lima; Alves da Silva, Francineyde; Barbosa da Silva, Fábio Sérgio

2017-01-01

Libidibia ferrea is a species particular to the caatinga presenting medicinal properties for containing bioactive compounds. The use of Arbuscular Mycorrhizal Fungi (AMF) can increase the production of biomolecules in the legume leaves; however, no light has been shed on the role of symbiosis in maximizing metabolites production in the bark of L. ferrea stem. The aim was to select AMF that are efficient at increasing the production of phenolic compounds with medicinal properties in the bark of the L. ferrea stem. The experiment was designed in randomized blocks with four inoculation treatments (plants pre-inoculated with Claroideoglomus etunicatum , with Gigaspora albida , with Acaulospora longula , and non-inoculated plants - control) with six repetitions. Thirteen months after the transplanting, the plants were pruned and the bark of the stem was collected; subsequently, this plant material was dried in a chamber. After the drying process, fractions of the bark of the stem were macerated in methanol. The extracts were further used for analyses of the biomolecules. The flavonoids concentration had an increase of, respectively, 236% and 186% in relation to the control for the treatments with A. longula and C. etunicatum ; plants inoculated with A. longula had an increase of 47% in total tannins concentration compared with the non-inoculated control - a benefit that the proanthocyanidins did not present. Applying inoculation with A. longula may be an alternative to increase the production of biomolecules of the secondary metabolism in the bark of the L. ferrea stem in field conditions.

Stem breakage of salt marsh vegetation under wave forcing: A field and model study

Science.gov (United States)

Vuik, Vincent; Suh Heo, Hannah Y.; Zhu, Zhenchang; Borsje, Bas W.; Jonkman, Sebastiaan N.

2018-01-01

One of the services provided by coastal ecosystems is wave attenuation by vegetation, and subsequent reduction of wave loads on flood defense structures. Therefore, stability of vegetation under wave forcing is an important factor to consider. This paper presents a model which determines the wave load that plant stems can withstand before they break or fold. This occurs when wave-induced bending stresses exceed the flexural strength of stems. Flexural strength was determined by means of three-point-bending tests, which were carried out for two common salt marsh species: Spartina anglica (common cord-grass) and Scirpus maritimus (sea club-rush), at different stages in the seasonal cycle. Plant stability is expressed in terms of a critical orbital velocity, which combines factors that contribute to stability: high flexural strength, large stem diameter, low vegetation height, high flexibility and a low drag coefficient. In order to include stem breakage in the computation of wave attenuation by vegetation, the stem breakage model was implemented in a wave energy balance. A model parameter was calibrated so that the predicted stem breakage corresponded with the wave-induced loss of biomass that occurred in the field. The stability of Spartina is significantly higher than that of Scirpus, because of its higher strength, shorter stems, and greater flexibility. The model is validated by applying wave flume tests of Elymus athericus (sea couch), which produced reasonable results with regards to the threshold of folding and overall stem breakage percentage, despite the high flexibility of this species. Application of the stem breakage model will lead to a more realistic assessment of the role of vegetation for coastal protection.

Potentiation of the antiinflammatory effect of Anacardium occidentale (Linn.) stem-bark aqueous extract by grapefruit juice.

Science.gov (United States)

Ojewole, J A O

2004-04-01

In an attempt to scientifically appraise some of the ethnomedical uses of Anacardium occidentale Linn. (family: Anacardiaceae), the present study was undertaken to examine the antiinflammatory effect of the plant's stem-bark aqueous extract in rats. Young adult male Wistar rats weighing 250-300 g were used. The antiinflammatory effect of A. occidentale stem-bark aqueous extract alone and in combination with grapefruit (Citrus paradisi Macf.) juice was investigated on fresh egg albumin-induced rat paw edema. Like diclofenac (100 mg/kg p.o.), aqueous extract of A. occidentale stem-bark (800 mg/kg p.o.) produced time-related, sustained and significant reduction (p extract was found to be approximately 8-15 times less than that of diclofenac. Coadministration of grapefruit juice (5 ml/kg p.o.) with A. occidentale stem-bark aqueous extract (800 mg/kg p.o.) or diclofenac (100 mg/kg p.o.) significantly potentiated (p extract and diclofenac on fresh egg albumin-induced rat paw edema. Although A. occidentale stem-bark aqueous extract is less potent than diclofenac as an antiinflammatory agent, the results of this experimental animal study indicate that the plant extract possesses antiinflammatory activity, and thus lend pharmacological support to the folkloric use of the plant in the management and/or control of arthritis and other inflammatory conditions among the Yoruba-speaking people of western Nigeria.

The Effects of Cold Stress on Photosynthesis in Hibiscus Plants

Science.gov (United States)

Paredes, Miriam; Quiles, María José

2015-01-01

The present work studies the effects of cold on photosynthesis, as well as the involvement in the chilling stress of chlororespiratory enzymes and ferredoxin-mediated cyclic electron flow, in illuminated plants of Hibiscus rosa-sinensis. Plants were sensitive to cold stress, as indicated by a reduction in the photochemistry efficiency of PSII and in the capacity for electron transport. However, the susceptibility of leaves to cold may be modified by root temperature. When the stem, but not roots, was chilled, the quantum yield of PSII and the relative electron transport rates were much lower than when the whole plant, root and stem, was chilled at 10°C. Additionally, when the whole plant was cooled, both the activity of electron donation by NADPH and ferredoxin to plastoquinone and the amount of PGR5 polypeptide, an essential component of the cyclic electron flow around PSI, increased, suggesting that in these conditions cyclic electron flow helps protect photosystems. However, when the stem, but not the root, was cooled cyclic electron flow did not increase and PSII was damaged as a result of insufficient dissipation of the excess light energy. In contrast, the chlororespiratory enzymes (NDH complex and PTOX) remained similar to control when the whole plant was cooled, but increased when only the stem was cooled, suggesting the involvement of chlororespiration in the response to chilling stress when other pathways, such as cyclic electron flow around PSI, are insufficient to protect PSII. PMID:26360248

Crossing kingdoms: Using decellularized plants as perfusable tissue engineering scaffolds.

Science.gov (United States)

Gershlak, Joshua R; Hernandez, Sarah; Fontana, Gianluca; Perreault, Luke R; Hansen, Katrina J; Larson, Sara A; Binder, Bernard Y K; Dolivo, David M; Yang, Tianhong; Dominko, Tanja; Rolle, Marsha W; Weathers, Pamela J; Medina-Bolivar, Fabricio; Cramer, Carole L; Murphy, William L; Gaudette, Glenn R

2017-05-01

Despite significant advances in the fabrication of bioengineered scaffolds for tissue engineering, delivery of nutrients in complex engineered human tissues remains a challenge. By taking advantage of the similarities in the vascular structure of plant and animal tissues, we developed decellularized plant tissue as a prevascularized scaffold for tissue engineering applications. Perfusion-based decellularization was modified for different plant species, providing different geometries of scaffolding. After decellularization, plant scaffolds remained patent and able to transport microparticles. Plant scaffolds were recellularized with human endothelial cells that colonized the inner surfaces of plant vasculature. Human mesenchymal stem cells and human pluripotent stem cell derived cardiomyocytes adhered to the outer surfaces of plant scaffolds. Cardiomyocytes demonstrated contractile function and calcium handling capabilities over the course of 21 days. These data demonstrate the potential of decellularized plants as scaffolds for tissue engineering, which could ultimately provide a cost-efficient, "green" technology for regenerating large volume vascularized tissue mass. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Antioxidant compounds and activities of the stem, flower, and leaf extracts of the anti-smoking Thai medicinal plant: Vernonia cinerea Less

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Ketsuwan N

2017-02-01

Full Text Available Nitinet Ketsuwan,1 Jirakrit Leelarungrayub,1 Suchart Kothan,2 Supawatchara Singhatong3 1Department of Physical Therapy, 2Department of Radiologic Technology, 3Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand Abstract: Vernonia cinerea (VC Less has been proposed as a medicinal plant with interesting activities, such as an aid for smoking cessation worldwide. Despite its previous clinical success in smoking cessation by exhibiting reduced oxidative stress, it has not been approved. The aim of this study was to investigate various antioxidant activity and active compounds that have not been approved, including the protective activity in human red blood cells (RBCs, from the stem, flower, and leaf extracts of VC Less in vitro. These extracts were tested for their antioxidant activity in scavenging 1,1-diphenyl-2-picrylhydrazyl (DPPH radicals and analyzed by high-performance liquid chromatography (HPLC for their active compounds: total tannin, five catechin (C compounds (epicatechin gallate [ECG], C, epicatechin [EC], epigallocatechin gallate [EGCG], and (--epigallocatechin [EGC], flavonoid, nitrite, nitrate, caffeine, and nicotine. Moreover, antioxidant activities of the extracts were evaluated in 2,2'-azobis(2-amidinopropane dihydrochloride (AAPH-treated RBCs. The results showed that the flower and leaf of VC Less had higher activity than the stem in scavenging DPPH radicals. The tannin content in the flower and leaf was higher than that in the stem. The leaf had the highest content of the five catechins (C, EC, EGCG, ECG, and EGC, the same as in the flavonoid, when compared to the stem and flower. Furthermore, the leaf extract had higher nitrate and nitrite than the stem. Nicotine content was found to be higher in the leaf when compared to the flower. In addition, the leaf showed protective activity in glutathione (GSH, malondialdehyde (MDA, and protein carbonyl, with a dose

Morpho-histological analysis of tomato (Solanum lycopersicum L. plants after treatment with juglone

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Anna Milewska-Hendel

2017-06-01

Full Text Available Juglone is a substance that limits plant growth and has a toxic effect on plant development. In this study, we analyzed the influence of juglone at two different concentrations (10−3 M and 10−4 M, which were applied to different parts of Solanum lycopersicum L. plants (root system, stem after decapitation, and surface of a younger leaf or after autografting for a short period of time (7 days, on the morphology and histology of stems. At a lower concentration, juglone had positive effects on plant growth, which resulted in an increase in interfascicular cambial cell divisions, faster development of a continuous cambium layer along the stem circumference, and development of fibers. Additionally, under the influence of juglone, the number of developing leaves increased and adventitious roots developed. The results are discussed based on the current literature concerning the reaction of plants to juglone and to stress conditions.

Stem photosynthesis in a desert ephemeral, Eriogonum inflatum : Characterization of leaf and stem CO2 fixation and H2O vapor exchange under controlled conditions.

Science.gov (United States)

Osmond, C B; Smith, S D; Gui-Ying, B; Sharkey, T D

1987-07-01

The gas exchange characteristics of photosynthetic tissues of leaves and stems of Eriogonum inflatum are described. Inflated stems were found to contain extraordinarily high internal CO 2 concentrations (to 14000 μbar), but fixation of this internal CO 2 was 6-10 times slower than fixation of atmospheric CO 2 by these stems. Although the pool of CO 2 is a trivial source of CO 2 for stem photosynthesis, it may result in higher water-use efficiency of stem tissues. Leaf and stem photosynthetic activities were compared by means of CO 2 fixation in CO 2 response curves, light and temperature response curves in IRGA systems, and by means of O 2 exchange at CO 2 saturation in a leaf disc O 2 electrode system. On an area basis leaves contain about twice the chlorophyll and nitrogen as stems, and are capable of up to 4-times the absolute CO 2 and O 2 exchange rates. However, the stem shape is such that lighting of the shaded side leads to a substantial increase in overall stem photosynthesis on a projected area basis, to about half the leaf rate in air. Stem conductance is lower than leaf conductance under most conditions and is less sensitive to high temperature or high VPD. Under most conditions, the ratio C i /C a is lower in stems than in leaves and stems show greater water-use efficiency (higher ratio assimilation/transpiration) as a function of VPD. This potential advantage of stem photosynthesis in a water limited environment may be offset by the higher VPD conditions in the hotter, drier part of the year when stems are active after leaves have senesced. Stem and leaf photosynthesis were similarly affected by decreasing plant water potential.

Oxygen dynamics during submergence in the halophytic stem succulent Halosarcia pergranulata

DEFF Research Database (Denmark)

Pedersen, Ole; Vos, Harrie; Colmer, Timothy David

2006-01-01

This study elucidated O2 dynamics in shoots and roots of submerged Halosarcia pergranulata (Salicornioideae), a perennial halophytic stem succulent that grows on flood-prone mudflats of salt lakes. Oxygen within shoots and roots was measured using microelectrodes, for plants when waterlogged...... the roots, at least during the first several hours (the time period measured) after submergence or when light periods followed darkness. The influence of light on tissue O2 dynamics was confirmed in an experiment on a submerged plant in a salt lake in south-western Australia. In the late afternoon, partial...... pressure of O2 (pO2) in the succulent stem was 23.2 kPa (i.e. ~10% above that in the air), while in the roots, it was 6.2-9.8 kPa. Upon sunset, the pO2 in the succulent stems declined within 1 h to below detection, but then showed some fluctuations with the pO2 increasing to at most 2.5 kPa during...

Effect of Calcium Sprays on Mechanical Strength and Cell Wall Fractions of Herbaceous Peony (Paeonia Lactiflora Pall. Inflorescence Stems

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Jintao Ge

2012-04-01

Full Text Available Calcium is an essential element and imparts significant structural rigidity to the plant cell walls, which provide the main mechanical support to the entire plant. In order to increase the mechanical strength of the inflorescence stems of herbaceous peony, the stems are treated with calcium chloride. The results shows that preharvest sprays with 4% (w/v calcium chloride three times after bud emergence are the best at strengthening “Da Fugui” peonies’ stems. Calcium sprays increased the concentrations of endogenous calcium, total pectin content as well as cell wall fractions in herbaceous peonies stems, and significantly increased the contents of them in the top segment. Correlation analysis showed that the breaking force of the top segment of peonies’ stems was positively correlated with the ratio of water insoluble pectin to water soluble pectin (R = 0.673 as well as lignin contents (R = 0.926 after calcium applications.

Identification of the arabidopsis RAM/MOR signalling network: adding new regulatory players in plant stem cell maintenance and cell polarization

Science.gov (United States)

Zermiani, Monica; Begheldo, Maura; Nonis, Alessandro; Palme, Klaus; Mizzi, Luca; Morandini, Piero; Nonis, Alberto; Ruperti, Benedetto

2015-01-01

Background and Aims The RAM/MOR signalling network of eukaryotes is a conserved regulatory module involved in co-ordination of stem cell maintenance, cell differentiation and polarity establishment. To date, no such signalling network has been identified in plants. Methods Genes encoding the bona fide core components of the RAM/MOR pathway were identified in Arabidopsis thaliana (arabidopsis) by sequence similarity searches conducted with the known components from other species. The transcriptional network(s) of the arabidopsis RAM/MOR signalling pathway were identified by running in-depth in silico analyses for genes co-regulated with the core components. In situ hybridization was used to confirm tissue-specific expression of selected RAM/MOR genes. Key Results Co-expression data suggested that the arabidopsis RAM/MOR pathway may include genes involved in floral transition, by co-operating with chromatin remodelling and mRNA processing/post-transcriptional gene silencing factors, and genes involved in the regulation of pollen tube polar growth. The RAM/MOR pathway may act upstream of the ROP1 machinery, affecting pollen tube polar growth, based on the co-expression of its components with ROP-GEFs. In silico tissue-specific co-expression data and in situ hybridization experiments suggest that different components of the arabidopsis RAM/MOR are expressed in the shoot apical meristem and inflorescence meristem and may be involved in the fine-tuning of stem cell maintenance and cell differentiation. Conclusions The arabidopsis RAM/MOR pathway may be part of the signalling cascade that converges in pollen tube polarized growth and in fine-tuning stem cell maintenance, differentiation and organ polarity. PMID:26078466

Effect of mechanical damage and wound healing on the viscoelastic properties of stems of flax cultivars (Linum usitatissimum L. cv. Eden and cv. Drakkar).

Science.gov (United States)

Paul-Victor, Cloé; Dalle Vacche, Sara; Sordo, Federica; Fink, Siegfried; Speck, Thomas; Michaud, Véronique; Speck, Olga

2017-01-01

As plant fibres are increasingly used in technical textiles and their composites, underlying principles of wound healing in living plant fibres are relevant to product quality, and provide inspiration for biomimetic healing in synthetic materials. In this work, two Linum usitatissimum cultivars differing in their stem mechanical properties, cv. Eden (stems resistant to lodging) and cv. Drakkar (with more flexible stems), were grown without wound or with stems previously wounded with a cut parallel or transversal to the stem. To investigate wound healing efficiency, growth traits, stem biomechanics with Dynamic Mechanical Analysis and anatomy were analysed after 25-day recovery. Longitudinal incisions formed open wounds while transversal incisions generated stem growth restoring the whole cross-section but not the original stem organisation. In the case of transversal wound healing, all the bast fibre bundles in the perturbed area became lignified and pulled apart by parenchyma cells growth. Both Linum cultivars showed a healing efficiency from 79% to 95% with higher scores for transversal healing. Morphological and anatomical modifications of Linum were related to mechanical properties and healing ability. Alongside with an increased understanding of wound healing in plants, our results highlight their possible impact on textile quality and fibre yield.

Holistic and component plant phenotyping using temporal image sequence.

Science.gov (United States)

Das Choudhury, Sruti; Bashyam, Srinidhi; Qiu, Yumou; Samal, Ashok; Awada, Tala

2018-01-01

Image-based plant phenotyping facilitates the extraction of traits noninvasively by analyzing large number of plants in a relatively short period of time. It has the potential to compute advanced phenotypes by considering the whole plant as a single object (holistic phenotypes) or as individual components, i.e., leaves and the stem (component phenotypes), to investigate the biophysical characteristics of the plants. The emergence timing, total number of leaves present at any point of time and the growth of individual leaves during vegetative stage life cycle of the maize plants are significant phenotypic expressions that best contribute to assess the plant vigor. However, image-based automated solution to this novel problem is yet to be explored. A set of new holistic and component phenotypes are introduced in this paper. To compute the component phenotypes, it is essential to detect the individual leaves and the stem. Thus, the paper introduces a novel method to reliably detect the leaves and the stem of the maize plants by analyzing 2-dimensional visible light image sequences captured from the side using a graph based approach. The total number of leaves are counted and the length of each leaf is measured for all images in the sequence to monitor leaf growth. To evaluate the performance of the proposed algorithm, we introduce University of Nebraska-Lincoln Component Plant Phenotyping Dataset (UNL-CPPD) and provide ground truth to facilitate new algorithm development and uniform comparison. The temporal variation of the component phenotypes regulated by genotypes and environment (i.e., greenhouse) are experimentally demonstrated for the maize plants on UNL-CPPD. Statistical models are applied to analyze the greenhouse environment impact and demonstrate the genetic regulation of the temporal variation of the holistic phenotypes on the public dataset called Panicoid Phenomap-1. The central contribution of the paper is a novel computer vision based algorithm for

Constituents of the Stems of Arbutus unedo.

Science.gov (United States)

Karikas, G A; Euerby, M R; Waigh, R D

1987-04-01

The dried stems of ARBUTUS UNEDO have been investigated for secondary metabolites. In addition to the previously reported lupeol, ursolic acid, monotropein, unedoside, and stilbericoside, the iridoids geniposide ( 2) and monotropein methyl ester ( 1) have been isolated for the first time from this source. Betulinic acid ( 4) has also been isolated for the first time from this plant.

Platinum bioaccumulation by mustard plants (Sinapis alba L.)

International Nuclear Information System (INIS)

Hawienczyk, M.; Bystrzejewska-Piotrowska, G.; Kowalska, J.; Asztemborska, M.

2005-01-01

The ability of hydroponically cultivated Indian mustard plants (Sinapis alba L.) to accumulate platinum was investigated. The Pt-bioaccumulation in leaves, stem and shoots of plants growing for 2 and 4 weeks at Pt-concentration of 50 and 500 μg/L was compared. The relation between dry and fresh weight was also estimated. Adsorptive stripping voltammetry (AdSV) and mass spectrometry with inductively coupled plasma (ICP-MS) were applied for determination of Pt. Increasing Pt-concentration from 50 to 500 μg/L in the medium causes: (1) reduction of the root tissue hydration level at unchanged modification in aboveground parts of the plants and (2) decrease of the Pt transfer factor (TF) for roots and increase for leaves and stem. Duration of the culture influenced on Pt-accumulation in roots and in aboveground organs of mustard plants. Transfer factor for Pt between 560 and 1600 makes Indian mustard plants one at Pt-hyperaccumulators. Distribution of Pt-bioaccumulation in the plant organs may be useful for biomonitoring of platinum in the environment. (author)

Agricultural Plant Pest Control. Bulletin 763.

Science.gov (United States)

French, John C.; And Others

This manual gives general information on plant pests and pesticides. First, the life-cycle and habits of some common insect pests are given. These include caterpillars, beetles and beetle larvae, and sucking insects. Next, plant diseases such as leaf diseases, wilts, root and crown rots, stem cankers, fruit rots, seed and seedling diseases, and…

Arbuscular Mycorrhizal Fungi Increase the Phenolic Compounds Concentration in the Bark of the Stem of Libidibia Ferrea in Field Conditions

Science.gov (United States)

dos Santos, Emanuela Lima; Alves da Silva, Francineyde; Barbosa da Silva, Fábio Sérgio

2017-01-01

Background: Libidibia ferrea is a species particular to the caatinga presenting medicinal properties for containing bioactive compounds. The use of Arbuscular Mycorrhizal Fungi (AMF) can increase the production of biomolecules in the legume leaves; however, no light has been shed on the role of symbiosis in maximizing metabolites production in the bark of L. ferrea stem. Objective: The aim was to select AMF that are efficient at increasing the production of phenolic compounds with medicinal properties in the bark of the L. ferrea stem. Methods: The experiment was designed in randomized blocks with four inoculation treatments (plants pre-inoculated with Claroideoglomus etunicatum, with Gigaspora albida, with Acaulospora longula, and non-inoculated plants – control) with six repetitions. Thirteen months after the transplanting, the plants were pruned and the bark of the stem was collected; subsequently, this plant material was dried in a chamber. After the drying process, fractions of the bark of the stem were macerated in methanol. The extracts were further used for analyses of the biomolecules. Results: The flavonoids concentration had an increase of, respectively, 236% and 186% in relation to the control for the treatments with A. longula and C. etunicatum; plants inoculated with A. longula had an increase of 47% in total tannins concentration compared with the non-inoculated control – a benefit that the proanthocyanidins did not present. Conclusion: Applying inoculation with A. longula may be an alternative to increase the production of biomolecules of the secondary metabolism in the bark of the L. ferrea stem in field conditions. PMID:29204223

Coordination of stem and leaf hydraulic conductance in southern California shrubs: a test of the hydraulic segmentation hypothesis.

Science.gov (United States)

Pivovaroff, Alexandria L; Sack, Lawren; Santiago, Louis S

2014-08-01

Coordination of water movement among plant organs is important for understanding plant water use strategies. The hydraulic segmentation hypothesis (HSH) proposes that hydraulic conductance in shorter lived, 'expendable' organs such as leaves and longer lived, more 'expensive' organs such as stems may be decoupled, with resistance in leaves acting as a bottleneck or 'safety valve'. We tested the HSH in woody species from a Mediterranean-type ecosystem by measuring leaf hydraulic conductance (Kleaf) and stem hydraulic conductivity (KS). We also investigated whether leaves function as safety valves by relating Kleaf and the hydraulic safety margin (stem water potential minus the water potential at which 50% of conductivity is lost (Ψstem-Ψ50)). We also examined related plant traits including the operating range of water potentials, wood density, leaf mass per area, and leaf area to sapwood area ratio to provide insight into whole-plant water use strategies. For hydrated shoots, Kleaf was negatively correlated with KS , supporting the HSH. Additionally, Kleaf was positively correlated with the hydraulic safety margin and negatively correlated with the leaf area to sapwood area ratio. Consistent with the HSH, our data indicate that leaves may act as control valves for species with high KS , or a low safety margin. This critical role of leaves appears to contribute importantly to plant ecological specialization in a drought-prone environment. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

Tree Species with Photosynthetic Stems Have Greater Nighttime Sap Flux

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Xia Chen

2018-01-01

Full Text Available An increasing body of evidence has shown that nighttime sap flux occurs in most plants, but the physiological implications and regulatory mechanism are poorly known. The significance of corticular photosynthesis has received much attention during the last decade, however, the knowledge of the relationship between corticular photosynthesis and nocturnal stem sap flow is limited at present. In this study, we divided seven tree species into two groups according to different photosynthetic capabilities: trees of species with (Castanopsis hystrix, Michelia macclurei, Eucalyptus citriodora, and Eucalyptus grandis × urophylla and without (Castanopsis fissa, Schima superba, and Acacia auriculiformis photosynthetic stems, and the sap flux (Js and chlorophyll fluorescence parameters for these species were measured. One-way ANOVA analysis showed that the Fv/Fm (Maximum photochemical quantum yield of PSII and ΦPSII (effective photochemical quantum yield of PSII values were lower in non-photosynthetic stem species compared to photosynthetic stem species. The linear regression analysis showed that Js,d (daytime sap flux and Js,n (nighttime sap flux of non-photosynthetic stem species was 87.7 and 60.9% of the stem photosynthetic species. Furthermore, for a given daytime transpiration water loss, total nighttime sap flux was higher in species with photosynthetic stems (SlopeSMA = 2.680 than in non-photosynthetic stems species (SlopeSMA = 1.943. These results mean that stem corticular photosynthesis has a possible effect on the nighttime water flow, highlighting the important eco-physiological relationship between nighttime sap flux and corticular photosynthesis.

Tree Species with Photosynthetic Stems Have Greater Nighttime Sap Flux

Science.gov (United States)

Chen, Xia; Gao, Jianguo; Zhao, Ping; McCarthy, Heather R.; Zhu, Liwei; Ni, Guangyan; Ouyang, Lei

2018-01-01

An increasing body of evidence has shown that nighttime sap flux occurs in most plants, but the physiological implications and regulatory mechanism are poorly known. The significance of corticular photosynthesis has received much attention during the last decade, however, the knowledge of the relationship between corticular photosynthesis and nocturnal stem sap flow is limited at present. In this study, we divided seven tree species into two groups according to different photosynthetic capabilities: trees of species with (Castanopsis hystrix, Michelia macclurei, Eucalyptus citriodora, and Eucalyptus grandis × urophylla) and without (Castanopsis fissa, Schima superba, and Acacia auriculiformis) photosynthetic stems, and the sap flux (Js) and chlorophyll fluorescence parameters for these species were measured. One-way ANOVA analysis showed that the Fv/Fm (Maximum photochemical quantum yield of PSII) and ΦPSII (effective photochemical quantum yield of PSII) values were lower in non-photosynthetic stem species compared to photosynthetic stem species. The linear regression analysis showed that Js,d (daytime sap flux) and Js,n (nighttime sap flux) of non-photosynthetic stem species was 87.7 and 60.9% of the stem photosynthetic species. Furthermore, for a given daytime transpiration water loss, total nighttime sap flux was higher in species with photosynthetic stems (SlopeSMA = 2.680) than in non-photosynthetic stems species (SlopeSMA = 1.943). These results mean that stem corticular photosynthesis has a possible effect on the nighttime water flow, highlighting the important eco-physiological relationship between nighttime sap flux and corticular photosynthesis. PMID:29416547

Caesium Radionuclide Uptake from Wet Soil to Kangkung Plant (Ipomoea sp)

International Nuclear Information System (INIS)

Putu Sukmabuana; Poppy Intan Tjahaja

2009-01-01

Caesium radionuclide transfer from soil to kangkung plant (Ipomoea sp) generally consumed by people had been examined to obtain transfer factor value for internal radiation dose assessment via soil-plant-human pathway. The kangkung plants were cultivated on watered soil medium containing 134 Cs with concentration of about 80 Bq/g, and the 134 Cs uptake by plants, i.e root, stem, and leaves, were measured using gamma spectrometer. The 134 Cs plant uptake was expressed as transfer factor, i.e. ratio of plant 134 Cs concentration to 134 Cs concentration on soil medium. From this research it was obtained transfer factor value of 134 C from soil to plant is 0.07, and the transfer factor for root, stem, and leaves are 0.34 ; 0.05 ; 0,03 respectively, after 45 days cultivation. The transfer factor values are less than one, indicate that kangkung plant do not accumulate Cs radionuclide from soil. (author)

Review: Wind impacts on plant growth, mechanics and damage.

Science.gov (United States)

Gardiner, Barry; Berry, Peter; Moulia, Bruno

2016-04-01

Land plants have adapted to survive under a range of wind climates and this involve changes in chemical composition, physical structure and morphology at all scales from the cell to the whole plant. Under strong winds plants can re-orientate themselves, reconfigure their canopies, or shed needles, leaves and branches in order to reduce the drag. If the wind is too strong the plants oscillate until the roots or stem fail. The mechanisms of root and stem failure are very similar in different plants although the exact details of the failure may be different. Cereals and other herbaceous crops can often recover after wind damage and even woody plants can partially recovery if there is sufficient access to water and nutrients. Wind damage can have major economic impacts on crops, forests and urban trees. This can be reduced by management that is sensitive to the local site and climatic conditions and accounts for the ability of plants to acclimate to their local wind climate. Wind is also a major disturbance in many plant ecosystems and can play a crucial role in plant regeneration and the change of successional stage. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Plant stem bark extractivism in the northeast semiarid region of Brazil: a new aport to utilitarian redundancy model.

Science.gov (United States)

Ferreira Júnior, Washington Soares; Siqueira, Clarissa Fernanda Queiroz; de Albuquerque, Ulysses Paulino

2012-01-01

We use the model of utilitarian redundancy as a basis for research. This model provides predictions that have not been tested by other research. In this sense, we sought to investigate the stem bark extraction between preferred and less-preferred species by a rural community in Caatinga environment. In addition, we sought to explain local preferences to observe if preferred plants have a higher content of tannins than less-preferred species. For this, we selected seven preferred species and seven less-preferred species from information obtained from semistructured interviews applied to 49 informants. Three areas of vegetation around the community were also selected, in which individuals were tagged, and were measured the diameter at ground level (DGL) diameter at breast height (DBH), and measurements of available and extracted bark areas. Samples of bark of the species were also collected for the evaluation of tannin content, obtained by the method of radial diffusion. From the results, the preferred species showed a greater area of bark removed. However, the tannin content showed no significant differences between preferred and less-preferred plants. These results show there is a relationship between preference and use, but this preference is not related to the total tannins content.

Plant Stem Bark Extractivism in the Northeast Semiarid Region of Brazil: A New Aport to Utilitarian Redundancy Model

Directory of Open Access Journals (Sweden)

Washington Soares Ferreira Júnior

2012-01-01

Full Text Available We use the model of utilitarian redundancy as a basis for research. This model provides predictions that have not been tested by other research. In this sense, we sought to investigate the stem bark extraction between preferred and less-preferred species by a rural community in Caatinga environment. In addition, we sought to explain local preferences to observe if preferred plants have a higher content of tannins than less-preferred species. For this, we selected seven preferred species and seven less-preferred species from information obtained from semistructured interviews applied to 49 informants. Three areas of vegetation around the community were also selected, in which individuals were tagged, and were measured the diameter at ground level (DGL diameter at breast height (DBH, and measurements of available and extracted bark areas. Samples of bark of the species were also collected for the evaluation of tannin content, obtained by the method of radial diffusion. From the results, the preferred species showed a greater area of bark removed. However, the tannin content showed no significant differences between preferred and less-preferred plants. These results show there is a relationship between preference and use, but this preference is not related to the total tannins content.

Plant Stem Bark Extractivism in the Northeast Semiarid Region of Brazil: A New Aport to Utilitarian Redundancy Model

Science.gov (United States)

Ferreira Júnior, Washington Soares; Siqueira, Clarissa Fernanda Queiroz; de Albuquerque, Ulysses Paulino

2012-01-01

We use the model of utilitarian redundancy as a basis for research. This model provides predictions that have not been tested by other research. In this sense, we sought to investigate the stem bark extraction between preferred and less-preferred species by a rural community in Caatinga environment. In addition, we sought to explain local preferences to observe if preferred plants have a higher content of tannins than less-preferred species. For this, we selected seven preferred species and seven less-preferred species from information obtained from semistructured interviews applied to 49 informants. Three areas of vegetation around the community were also selected, in which individuals were tagged, and were measured the diameter at ground level (DGL) diameter at breast height (DBH), and measurements of available and extracted bark areas. Samples of bark of the species were also collected for the evaluation of tannin content, obtained by the method of radial diffusion. From the results, the preferred species showed a greater area of bark removed. However, the tannin content showed no significant differences between preferred and less-preferred plants. These results show there is a relationship between preference and use, but this preference is not related to the total tannins content. PMID:22319546

Aquatic adventitious roots of the wetland plant Meionectes brownii can photosynthesize

DEFF Research Database (Denmark)

Rich, Sarah Meghan; Ludwig, Martha; Pedersen, Ole

2011-01-01

• Many wetland plants produce aquatic adventitious roots from submerged stems. Aquatic roots can form chloroplasts, potentially producing endogenous carbon and oxygen. Here, aquatic root photosynthesis was evaluated in the wetland plant Meionectes brownii, which grows extensive stem-borne aquatic...... roots during submergence. • Underwater photosynthetic light and CO(2) response curves were determined for aquatic-adapted leaves, stems and aquatic roots of M. brownii. Oxygen microelectrode and (14)CO(2)-uptake experiments determined shoot inputs of O(2) and photosynthate into aquatic roots. • Aquatic...... adventitious roots contain a complete photosynthetic pathway. Underwater photosynthetic rates are similar to those of stems, with a maximum net photosynthetic rate (P(max)) of 0.38 µmol O(2) m(-2) s(-1); however, this is c. 30-fold lower than that of aquatic-adapted leaves. Under saturating light with 300 mmol...

Involvement of membrane sterols in hypergravity-induced modifications of growth and cell wall metabolism in plant stems

Science.gov (United States)

Koizumi, T.; Soga, K.; Wakabayashi, K.; Suzuki, M.; Muranaka, T.; Hoson, T.

Organisms living on land resist the gravitational force by constructing a tough body Plants have developed gravity resistance responses after having first went ashore more than 500 million years ago The mechanisms of gravity resistance responses have been studied under hypergravity conditions which are easily produced on earth by centrifugation In Arabidopsis hypocotyls hypergravity treatment greatly increased the expression level of 3-hydroxy-3-methylglutaryl-Coenzyme A reductase HMGR which is involved in synthesis of terpenoids such as membrane sterols In the present study we examined the role of membrane sterols in gravity resistance in plants by analyzing sterol levels of stem organs grown under hypergravity conditions and by analyzing responses to hypergravity of the organs whose sterol level was modulated Hypergravity inhibited elongation growth but stimulated lateral expansion of Arabidopsis hypocotyls and azuki bean epicotyls Under hypergravity conditions sterol levels were kept high as compared with 1 g controls during incubation Lovastatin an inhibitor HMGR prevented lateral expansion as the gravity resistance response in azuki bean epicotyls Similar results were obtained in analyses with loss of function mutants of HMGR in Arabidopsis It has been shown that sterols play a role in cellulose biosynthesis probably as the primer In wild type Arabidopsis hypocotyls hypergravity increased the cellulose content but it did not influence the content in HMGR mutants These results suggest that hypergravity increases

Cell walls and the developmental anatomy of the Brachypodium distachyon stem internode.

Directory of Open Access Journals (Sweden)

Dominick A Matos

Full Text Available While many aspects of plant cell wall polymer structure are known, their spatial and temporal distribution within the stem are not well understood. Here, we studied vascular system and fiber development, which has implication for both biofuel feedstock conversion efficiency and crop yield. The subject of this study, Brachypodium distachyon, has emerged as a grass model for food and energy crop research. Here, we conducted our investigation using B. distachyon by applying various histological approaches and Fourier transform infrared spectroscopy to the stem internode from three key developmental stages. While vascular bundle size and number did not change over time, the size of the interfascicular region increased dramatically, as did cell wall thickness. We also describe internal stem internode anatomy and demonstrate that lignin deposition continues after crystalline cellulose and xylan accumulation ceases. The vascular bundle anatomy of B. distachyon appears to be highly similar to domesticated grasses. While the arrangement of bundles within the stem is highly variable across grasses, B. distachyon appears to be a suitable model for the rind of large C4 grass crops. A better understanding of growth and various anatomical and cell wall features of B. distachyon will further our understanding of plant biomass accumulation processes.

Root Formation in Ethylene-Insensitive Plants1

Science.gov (United States)

Clark, David G.; Gubrium, Erika K.; Barrett, James E.; Nell, Terril A.; Klee, Harry J.

1999-01-01

Experiments with ethylene-insensitive tomato (Lycopersicon esculentum) and petunia (Petunia × hybrida) plants were conducted to determine if normal or adventitious root formation is affected by ethylene insensitivity. Ethylene-insensitive Never ripe (NR) tomato plants produced more belowground root mass but fewer aboveground adventitious roots than wild-type Pearson plants. Applied auxin (indole-3-butyric acid) increased adventitious root formation on vegetative stem cuttings of wild-type plants but had little or no effect on rooting of NR plants. Reduced adventitious root formation was also observed in ethylene-insensitive transgenic petunia plants. Applied 1-aminocyclopropane-1-carboxylic acid increased adventitious root formation on vegetative stem cuttings from NR and wild-type plants, but NR cuttings produced fewer adventitious roots than wild-type cuttings. These data suggest that the promotive effect of auxin on adventitious rooting is influenced by ethylene responsiveness. Seedling root growth of tomato in response to mechanical impedance was also influenced by ethylene sensitivity. Ninety-six percent of wild-type seedlings germinated and grown on sand for 7 d grew normal roots into the medium, whereas 47% of NR seedlings displayed elongated taproots, shortened hypocotyls, and did not penetrate the medium. These data indicate that ethylene has a critical role in various responses of roots to environmental stimuli. PMID:10482660

Rooting of healthy and CVC-affected 'Valência' sweet orange stem cuttings, through the use of plant regulators

Directory of Open Access Journals (Sweden)

Gustavo Habermann

2006-01-01

Full Text Available Citrus variegated chlorosis (CVC is a disease caused by Xylella fastidiosa. Using different concentrations of plant regulators, such as auxins (indole-3-butyric acid and gibberellic acid biosynthesis-inhibitor (paclobutrazol, physiological rooting capacity of healthy and CVC-affected stem cuttings were evaluated in order to investigate the importance of plant hormone imbalance and xylem occlusion in plants with CVC. The percentages of dead, alive and rooted cuttings, cuttings with callus and mean number of roots per cuttings did not show statistical differences in response to the distinct concentrations of synthetic plant regulators. There were differences only between healthy and CVC-affected cuttings. This showed the importance of xylem occlusion and diffusive disturbances in diseased plants, in relation to root initiation capacity and hormonal translocation in the plant tissue.Clorose variegada dos citros (CVC é uma doença causada por Xylella fastidiosa, podendo determinar oclusão do xilema e desbalanço hormonal, o que por fim está relacionado ao processo de iniciação radicial em estacas. Usando diferentes concentrações de fitorreguladores, como auxinas (ácido 3-indol butírico e inibidores da biossíntese de ácido giberélico (paclobutrazol, que são promotores do enraizamento de estacas, verificou-se a capacidade fisiológica de enraizamento de estacas sadias e com CVC, a fim de investigar a importância do desbalanço hormonal e oclusão do xilema em plantas doentes. As porcentagens de estacas mortas, vivas, enraizadas e com calo e o número médio de raízes por estaca não mostraram diferenças estatísticas em resposta às diferentes concentrações dos reguladores vegetais sintéticos. Houve diferenças apenas entre estacas sadias e doentes. Isto aponta a importância da oclusão do xilema e distúrbios difusivos em plantas doentes, em relação à capacidade de iniciação radicial e à translocação hormonal no tecido

Stem Cells

Science.gov (United States)

Stem cells are cells with the potential to develop into many different types of cells in the body. ... the body. There are two main types of stem cells: embryonic stem cells and adult stem cells. Stem ...

Efficacy of the stem powder of an invasive alien plant, Chromolaena ...

African Journals Online (AJOL)

ADOWIE PERE

2018-03-15

Mar 15, 2018 ... insecticidal activities of C. odorata stem powder and further suggests its usage as an attractive alternative to synthetic insecticides in the ... Creative Commons Attribution License (CCL), which permits unrestricted use, distribution, and reproduction in .... grains was placed inside a screw top plastic container.

Diversity of Endophytic Fungi from Red Ginger (Zingiber officinale Rosc. Plant and Their Inhibitory Effect to Fusarium oxysporum Plant Pathogenic Fungi

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ROHANI CINTA BADIA GINTING

2013-09-01

Full Text Available Indonesia has been known as a country with high medicinal plant diversity. One of the most common medicinal plant from Indonesia is red ginger (Zingiber officinale Rosc.. Nevertheless, limited studies of endophytic fungi associated with these medicinal plants are hitherto available. The objectives of this research were to study the diversity of endophytic fungi on red ginger and to analyze their potential as a source of antifungal agent. All parts of plant organs such as leaf, rhizome, root, and stem were subjected for isolation. Fungal identification was carried out by using a combination of morphological characteristic and molecular analysis of DNA sequence generated from ITS rDNA region. Thirty endophytic fungi were successfully isolated from leaf, rhizome, root, and stem of red ginger plant. Antagonistic activity was tested against Fusarium oxysporum, a pathogenic fungus on plants, using an antagonistic assay. Based on this approach, the fungi were assigned as Acremonium macroclavatum, Beltraniella sp., Cochliobolus geniculatus and its anamorphic stage Curvularia affinis, Fusarium solani, Glomerella cingulata and its anamorphic stage Colletotrichum gloeosporoides, Lecanicillium kalimantanense, Myrothecium verrucaria, Neonectria punicea, Periconia macrospinosa, Rhizopycnis vagum, and Talaromyces assiutensis. R. vagum was found specifically on root whereas C. affinis, L. kalimantanense, and M. verrucaria were found on stem of red ginger plant. A. macroclavatum was found specifically in red ginger plant's organ which located under the ground, whereas C. affinis was found from shoot or organ which located above the ground. The antagonistic activity of isolated endophytic fungi against F. oxysporum varied with the inhibition value range from 1.4 to 68.8%. C. affinis (JMbt7, F. solani (JMd14, and G. cingulata (JMr2 had significantly high antagonistic activity with the value above 65%; and R. vagum (JMa4 and C. geniculatus (JMbt9 had significantly

Assessment of maize stem borer damage on hybrid maize varieties in Chitwan, Nepal

OpenAIRE

Buddhi Bahadur Achhami; Santa Bahadur BK; Ghana Shyam Bhandari

2015-01-01

Maize is the second most important cereal crop in Nepal. However, national figure of grain production still remains below than the world's average grain production per unit area. Thus, this experiment was designed to determine the suitable time of maize planting, and to assess the peak period of one of the major insects, maize stem borer, in Chitwan condition. The results showed that plant damage percentage as per the maize planting month varies significantly, and the average plant damage per...

Chlorophyll mutation in field Pea (Pisum Sativum L.) that causes white stem in plants

International Nuclear Information System (INIS)

Naidenova, N.; Vassilevska-Ivanova, R.

2006-01-01

A white stem pea mutant recovered after exposing seeds of P. sativum cv Auralia to gamma-irradiation. The mutant has shown to have single-gene recessive inheritance, characterized morphologically and for seed productivity. New mutant 1/240 had similar phenotype to previously named mutants white stem and alts (albina-terminalis) but no allelism tests were performed between the new and the previously reported mutants. The mutation in line 1/240 may be useful as a genetic marker. (authors)

NMR, water and plants

International Nuclear Information System (INIS)

As, H. van.

1982-01-01

This thesis describes the application of a non-destructive pulsed proton NMR method mainly to measure water transport in the xylem vessels of plant stems and in some model systems. The results are equally well applicable to liquid flow in other biological objects than plants, e.g. flow of blood and other body fluids in human and animals. The method is based on a pulse sequence of equidistant π pulses in combination with a linear magnetic field gradient. (Auth.)

Plant size and abiotic factors determine the intra-specific variation in the multi-stemmed architecture of Prunus lusitanica in the Northeast limit of its global distribution

Directory of Open Access Journals (Sweden)

A. Muñoz Costa

2013-12-01

Full Text Available Aim of study: The present work provides novel insights on factors (either intrinsic or extrinsic that trigger sprouting in woody species living at range margins. We aim to explain the inter-individual variability in the multi-stemmed architecture of Prunus lusitanica L., an Iberian evergreen relict tree related to the Tertiary flora.Area of study: Northeastern Mediterranean mountains of the Iberian Peninsula, the Northeast limit of the global distribution of the species.Material and Methods: We gathered data on two modes of vegetative reproduction, basal and layering sprouts, in 288 clumps of Prunus lusitanica from four populations. We modeled and analyzed the effect of environmental factors (topography, canopy cover, soil moisture and disturbances and plant size (diameter at breast height on sprouting by means of Generalized Linear Model and other statistical approaches.Main results: Plant size arises as the principal factor to explain the variability of the numbers of both types of sprouts yet it is not a trigger factor. Natural and anthropogenic disturbances promote basal and layering shoots, while tree canopy is mainly relevant for basal shoots, and slope and soil moisture are significant factors for layering shoots.Research highlights: The multi-stemmed architecture of P. lusitanica at the Northeastern limit of its worldwide distribution is triggered by local environmental factors and disturbances. Each external factor shows different levels of influence on the variability and type of vegetative reproduction yet the intensity of the response is driven by the size of the largest trunk of each clump.Key words: vegetative reproduction; sprouting; disturbances; woody plants; relict tree; subtropical; Iberian Peninsula.

Toxicological studies of stem bark extract from Schefflera barteri Harms (Araliaceae).

Science.gov (United States)

Atsafack, Serge Secco; Kuiate, Jules-Roger; Mouokeu, Raymond Simplice; Koanga Mogtomo, Martin Luther; Tchinda, Alembert Tiabou; De Dieu, Tamokou Jean; Magnifouet Nana, Huguette; Ebelle Etame, Rébecca Madeleine; Biyiti, Lucie; Ngono Ngane, Rosalie Annie

2015-03-07

The use of herbal medicines as complements or alternatives to orthodox medicines has been on the increase. There has been the erroneous belief that these medicines are free from adverse effects. Schefflera barteri is popularly used in the West region of Cameroon for the treatment of various diseases such as diarrhea, spasm, pneumonia and animals bite. Considering the ethnopharmacological relevance of this plant, this study was designed to investigate the possible toxic effects of the stem bark extract of S. barteri. The extract was prepared by maceration of stem bark dry powder in methylene chloride/methanol mixture. Phytochemical analysis was performed by chemical reaction method. Oral acute toxicity study was carried out by administering single geometric increasing doses (2 to 16 g/kg body weight) of plant extract to Swiss albino mice. For sub-acute toxicity study, repeated doses (100, 200, 400 and 800 mg/kg bw) of plant extract were given to Wistar albino rats for 28 consecutive days by oral route. At the end of the treatment period, hematological and biochemical parameters were assessed, as well as histopathological studies. Phytochemical analysis of stem bark extract of S. barteri revealed the presence of anthocyanins, anthraquinons and saponins. Acute toxicity results showed that the LD50 was greater than 16000 mg/kg. Sub-acute treatment significantly (P congestion, inflammation of peri-portal and vacuolization of hepatocytes at the level of the liver. Leucocytes infiltration of peri-portal veins were noticed on lungs and liver cells as well as inflammatory peri-bronchial and basal membranes seminar tube merely joined on lungs and testis respectively. The results suggest that acute administration of the stem bark extract of S. barteri is associated with signs of toxicity, administration over a long duration provokes hepatotoxicity, testes and lungs toxicities.

Environmental Stresses of Field Growth Allow Cinnamyl Alcohol Dehydrogenase-Deficient Nicotiana attenuata Plants to Compensate for their Structural Deficiencies1[C][W][OA

Science.gov (United States)

Kaur, Harleen; Shaker, Kamel; Heinzel, Nicolas; Ralph, John; Gális, Ivan; Baldwin, Ian T.

2012-01-01

The organized lignocellulosic assemblies of cell walls provide the structural integrity required for the large statures of terrestrial plants. Silencing two CINNAMYL ALCOHOL DEHYDROGENASE (CAD) genes in Nicotiana attenuata produced plants (ir-CAD) with thin, red-pigmented stems, low CAD and sinapyl alcohol dehydrogenase activity, low lignin contents, and rubbery, structurally unstable stems when grown in the glasshouse (GH). However, when planted into their native desert habitat, ir-CAD plants produced robust stems that survived wind storms as well as the wild-type plants. Despite efficient silencing of NaCAD transcripts and enzymatic activity, field-grown ir-CAD plants had delayed and restricted spread of red stem pigmentation, a color change reflecting blocked lignification by CAD silencing, and attained wild-type-comparable total lignin contents. The rubbery GH phenotype was largely restored when field-grown ir-CAD plants were protected from wind, herbivore attack, and ultraviolet B exposure and grown in restricted rooting volumes; conversely, it was lost when ir-CAD plants were experimentally exposed to wind, ultraviolet B, and grown in large pots in growth chambers. Transcript and liquid chromatography-electrospray ionization-time-of-flight analysis revealed that these environmental stresses enhanced the accumulation of various phenylpropanoids in stems of field-grown plants; gas chromatography-mass spectrometry and nuclear magnetic resonance analysis revealed that the lignin of field-grown ir-CAD plants had GH-grown comparable levels of sinapaldehyde and syringaldehyde cross-linked into their lignins. Additionally, field-grown ir-CAD plants had short, thick stems with normal xylem element traits, which collectively enabled field-grown ir-CAD plants to compensate for the structural deficiencies associated with CAD silencing. Environmental stresses play an essential role in regulating lignin biosynthesis in lignin-deficient plants. PMID:22645069

Tree Species with Photosynthetic Stems Have Greater Nighttime Sap Flux.

Science.gov (United States)

Chen, Xia; Gao, Jianguo; Zhao, Ping; McCarthy, Heather R; Zhu, Liwei; Ni, Guangyan; Ouyang, Lei

2018-01-01

An increasing body of evidence has shown that nighttime sap flux occurs in most plants, but the physiological implications and regulatory mechanism are poorly known. The significance of corticular photosynthesis has received much attention during the last decade, however, the knowledge of the relationship between corticular photosynthesis and nocturnal stem sap flow is limited at present. In this study, we divided seven tree species into two groups according to different photosynthetic capabilities: trees of species with ( Castanopsis hystrix, Michelia macclurei, Eucalyptus citriodora , and Eucalyptus grandis × urophylla ) and without ( Castanopsis fissa, Schima superba , and Acacia auriculiformis ) photosynthetic stems, and the sap flux ( J s ) and chlorophyll fluorescence parameters for these species were measured. One-way ANOVA analysis showed that the F v / F m (Maximum photochemical quantum yield of PSII) and Φ PSII (effective photochemical quantum yield of PSII) values were lower in non-photosynthetic stem species compared to photosynthetic stem species. The linear regression analysis showed that J s,d (daytime sap flux) and J s,n (nighttime sap flux) of non-photosynthetic stem species was 87.7 and 60.9% of the stem photosynthetic species. Furthermore, for a given daytime transpiration water loss, total nighttime sap flux was higher in species with photosynthetic stems (Slope SMA = 2.680) than in non-photosynthetic stems species (Slope SMA = 1.943). These results mean that stem corticular photosynthesis has a possible effect on the nighttime water flow, highlighting the important eco-physiological relationship between nighttime sap flux and corticular photosynthesis.

Plant uptake of bicarbonate as measured with the 11C isotope

International Nuclear Information System (INIS)

Wallace, A.; Mueller, R.T.; Wood, R.A.; Soufi, S.M.

1979-01-01

11 C which is cyclotron produced by 14 N(P, α) 11 C(half-life 20.1 M) was used as a tracer of bicarbonate to determine its movements from a nutrient solution through roots to stems and leaves of bush bean plants (Phaseolus vulgaris L. var Improved Tendergreen). The short time involved and the high solution pH minimized the need for use of the Henderson Hasselbach equation for activity correction. Quantities of 11 C did move into roots, stems and leaves with a sharp decreasing gradient (root/stem = 14.5, stems/leaves = 11.7) More 11 C moved into plants with KHCO 3 than with NaHCO 3 . The (NH 4 ) 2 SO 4 enhanced 11 C uptake and KNO 3 decreased it. This enhancement and competition indicated possibility of some uptake of HCO 3 - . In an experiment with Galenia pubescens (Eckl. and Zeyh.) Druce, the 11 C was more readily moved to stems and leaves than in bush bean indicating substantial uptake of HCO 3 - . (Auth.)

Genome Regions Associated with Functional Performance of Soybean Stem Fibers in Polypropylene Thermoplastic Composites.

Directory of Open Access Journals (Sweden)

Yarmilla Reinprecht

Full Text Available Plant fibers can be used to produce composite materials for automobile parts, thus reducing plastic used in their manufacture, overall vehicle weight and fuel consumption when they replace mineral fillers and glass fibers. Soybean stem residues are, potentially, significant sources of inexpensive, renewable and biodegradable natural fibers, but are not curretly used for biocomposite production due to the functional properties of their fibers in composites being unknown. The current study was initiated to investigate the effects of plant genotype on the performance characteristics of soybean stem fibers when incorporated into a polypropylene (PP matrix using a selective phenotyping approach. Fibers from 50 lines of a recombinant inbred line population (169 RILs grown in different environments were incorporated into PP at 20% (wt/wt by extrusion. Test samples were injection molded and characterized for their mechanical properties. The performance of stem fibers in the composites was significantly affected by genotype and environment. Fibers from different genotypes had significantly different chemical compositions, thus composites prepared with these fibers displayed different physical properties. This study demonstrates that thermoplastic composites with soybean stem-derived fibers have mechanical properties that are equivalent or better than wheat straw fiber composites currently being used for manufacturing interior automotive parts. The addition of soybean stem residues improved flexural, tensile and impact properties of the composites. Furthermore, by linkage and in silico mapping we identified genomic regions to which quantitative trait loci (QTL for compositional and functional properties of soybean stem fibers in thermoplastic composites, as well as genes for cell wall synthesis, were co-localized. These results may lead to the development of high value uses for soybean stem residue.

A regional assessment of white-tailed deer effects on plant invasion

Science.gov (United States)

Mortensen, David A; Smithwick, Erica A H; Kalisz, Susan; McShea, William J; Bourg, Norman A; Parker, John D; Royo, Alejandro A; Abrams, Marc D; Apsley, David K; Blossey, Bernd; Boucher, Douglas H; Caraher, Kai L; DiTommaso, Antonio; Johnson, Sarah E; Masson, Robert; Nuzzo, Victoria A

2018-01-01

Abstract Herbivores can profoundly influence plant species assembly, including plant invasion, and resulting community composition. Population increases of native herbivores, e.g. white-tailed deer (Odocoileus virginianus), combined with burgeoning plant invasions raise concerns for native plant diversity and forest regeneration. While individual researchers typically test for the impact of deer on plant invasion at a few sites, the overarching influence of deer on plant invasion across regional scales is unclear. We tested the effects of deer on the abundance and diversity of introduced and native herbaceous and woody plants across 23 white-tailed deer research sites distributed across the east-central and north-eastern USA and representing a wide range of deer densities and invasive plant abundance and identity. Deer access/exclusion or deer population density did not affect introduced plant richness or community-level abundance. Native and total plant species richness, abundance (cover and stem density) and Shannon diversity were lower in deer-access vs. deer-exclusion plots. Among deer-access plots, native species richness, native and total cover, and Shannon diversity (cover) declined as deer density increased. Deer access increased the proportion of introduced species cover (but not of species richness or stem density). As deer density increased, the proportion of introduced species richness, cover and stem density all increased. Because absolute abundance of introduced plants was unaffected by deer, the increase in proportion of introduced plant abundance is likely an indirect effect of deer reducing native cover. Indicator species analysis revealed that deer access favoured three introduced plant species, including Alliaria petiolata and Microstegium vimineum, as well as four native plant species. In contrast, deer exclusion favoured three introduced plant species, including Lonicera japonica and Rosa multiflora, and 15 native plant species. Overall, native

A regional assessment of white-tailed deer effects on plant invasion

Energy Technology Data Exchange (ETDEWEB)

Averill, Kristine M. [Ecology Intercollege Graduate Degree Program, The Pennsylvania State University, University Park, PA, USA; Department of Plant Sciences, The Pennsylvania State University, University Park, PA, USA; Mortensen, David A. [Ecology Intercollege Graduate Degree Program, The Pennsylvania State University, University Park, PA, USA; Department of Plant Sciences, The Pennsylvania State University, University Park, PA, USA; Smithwick, Erica A. H. [Ecology Intercollege Graduate Degree Program, The Pennsylvania State University, University Park, PA, USA; Department of Geography, The Pennsylvania State University, University Park, PA, USA; Kalisz, Susan [Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN, USA; McShea, William J. [Smithsonian Conservation Biology Institute, Front Royal, VA, USA; Bourg, Norman A. [Smithsonian Conservation Biology Institute, Front Royal, VA, USA; Parker, John D. [Smithsonian Environmental Research Center, Edgewater, MD, USA; Royo, Alejandro A. [United States Department of Agriculture Forest Service, Northern Research Station, Irvine, PA, USA; Abrams, Marc D. [Ecology Intercollege Graduate Degree Program, The Pennsylvania State University, University Park, PA, USA; Department of Ecosystem Science and Management, The Pennsylvania State University, University Park, PA, USA; Apsley, David K. [Department of Extension, The Ohio State University, Jackson, OH, USA; Blossey, Bernd [Department of Natural Resources, Cornell University, Ithaca, NY, USA; Boucher, Douglas H. [Department of Biology, Hood College, Frederick, MD, USA; Caraher, Kai L. [Department of Biology, Hood College, Frederick, MD, USA; DiTommaso, Antonio [Soil and Crop Sciences Section, Cornell University, Ithaca, NY, USA; Johnson, Sarah E. [Ecology Intercollege Graduate Degree Program, The Pennsylvania State University, University Park, PA, USA; Department of Ecosystem Science and Management, The Pennsylvania State University, University Park, PA, USA; Masson, Robert [National Park Service, Morristown National Historical Park, Morristown, NJ, USA; Nuzzo, Victoria A. [Natural Area Consultants, Richford, NY, USA

2017-12-07

Herbivores can profoundly influence plant species assembly, including plant invasion, and resulting community composition. Population increases of native herbivores, e.g., white-tailed deer (Odocoileus virginianus), combined with burgeoning plant invasions raise concerns for native plant diversity and forest regeneration. While individual researchers typically test for the impact of deer on plant invasion at a few sites, the overarching influence of deer on plant invasion across regional scales is unclear. We tested the effects of deer on the abundance and diversity of introduced and native herbaceous and woody plants across 23 white-tailed deer research sites distributed across the east central and northeastern United States and representing a wide range of deer densities and invasive plant abundance and identity. Deer access/exclusion or deer population density did not affect introduced plant richness or community-level abundance. Native and total plant species richness, abundance (cover and stem density), and Shannon diversity were lower in deer-access vs. deer-exclusion plots. Among deer access plots, native species richness, native and total cover, and Shannon diversity (cover) declined as deer density increased. Deer access increased the proportion of introduced species cover (but not of species richness or stem density). As deer density increased, the proportion of introduced species richness, cover, and stem density all increased. Because absolute abundance of introduced plants was unaffected by deer, the increase in proportion of introduced plant abundance is likely an indirect effect of deer reducing native cover. Indicator species analysis revealed that deer access favored three introduced plant species, including Alliaria petiolata and Microstegium vimineum, as well as four native plant species. In contrast, deer exclusion favored three introduced plant species, including Lonicera japonica and Rosa multiflora, and fifteen native plant species. Overall

Effect of seed treatment with low-potency laser in peppers plants (Capsicum annuum L.

Directory of Open Access Journals (Sweden)

Alexander Álvarez Fonseca,

2014-01-01

Full Text Available The influence of seed treatment with low-potency laser radiation on some physiological parameters and yield of peppers plants, California Wonder variety, was studied. The seeds were irradiated with a laser He- Ne, 25 mW powers, at different exposure periods 5, 10, 20, 30 and 60 seconds, using untreated seeds as controls. We evaluated plant height (mm, root length (mm, stem diameter (mm, polar average diameter (mm equatorial mean diameter (mm, mean fruit mass (g and yield per plant (kg.plant-1. The results showed a significant increase (p?0.001 in the indicators of plants height (50 %, root length (13 %, stem diameter (17 %, equatorial mean diameter (7 %, mean fruit mass (13 % and yield per plant (67 %, compared to control.

Global models for the biomechanics of green plants: 1

International Nuclear Information System (INIS)

Bestman, A.R.

1990-12-01

The paper considers the biomechanics of green plants for Reynolds number flow in the stem. In particular, it is assumed that the stem is cylindrical and the flow fully-developed. So that if the aspect ratio is defined as the ratio of the stem radius to its length, then when the aspect ratio is small analytical solutions have been developed for the concentration, temperature and the axial velocity. The process of translocation and transpiration are discussed quantitatively. (author). 4 refs, 2 figs

Growth response of Casuarina equisetifolia Forst. rooted stem cuttings to Frankia in nursery and field conditions.

Science.gov (United States)

Karthikeyan, A; Chandrasekaran, K; Geetha, M; Kalaiselvi, R

2013-11-01

Casuarina equisetifolia Forst. is a tree crop that provides fuel wood, land reclamation, dune stabilization, and scaffolding for construction, shelter belts, and pulp and paper production. C. equisetifolia fixes atmospheric nitrogen through a symbiotic relationship with Frankia, a soil bacterium of the actinobacteria group. The roots of C. equisetifolia produce root nodules where the bacteria fix atmospheric nitrogen, which is an essential nutrient for all plant metabolic activities. However, rooted stem cuttings of elite clones of C. equisetifolia by vegetative propagation is being planted by the farmers of Pondicherry as costeffective method. As the vegetative propagation method uses inert material (vermiculite) for rooting there is no chance for Frankia association. Therefore after planting of these stocks the farmers are applying 150 kg of di-ammonium phosphate (DAP)/acre/year. To overcome this fertilizer usage, the Frankia-inoculated rooted stem cuttings were propagated under nursery conditions and transplanted in the nutrient-deficient soils of Karaikal, Pondicherry (India), in this study. Under nursery experiments the growth and biomass of C. equisetifolia rooted stem cuttings inoculated with Frankia showed 3 times higher growth and biomass than uninoculated control. These stocks were transplanted and monitored for their growth and survival for 1 year in the nutrient-deficient farm land. The results showed that the rooted stem cuttings of C. equisetifolia significantly improved growth in height (8.8 m), stem girth (9.6 cm) and tissue nitrogen content (3.3 mg g-1) than uninoculated controls. The soil nutrient status was also improved due to inoculation of Frankia.

Boron-isotope fractionation in plants

Energy Technology Data Exchange (ETDEWEB)

Marentes, E [Univ. of Guelph, Dept. of Horticultural Science, Guelph, Ontario (Canada); Vanderpool, R A [USDA/ARS Grand Forks Human Nutrition Research Center, Grand Forks, North Dakota (United States); Shelp, B J [Univ. of Guelph, Dept. of Horticultural Science, Guelph, Ontario (Canada)

1997-10-15

Naturally-occurring variations in the abundance of stable isotopes of carbon, nitrogen, oxygen, and other elements in plants have been reported and are now used to understand various physiological processes in plants. Boron (B) isotopic variation in several plant species have been documented, but no determination as to whether plants fractionate the stable isotopes of boron, {sup 11}B and {sup 10}B, has been made. Here, we report that plants with differing B requirements (wheat, corn and broccoli) fractionated boron. The whole plant was enriched in {sup 11}B relative to the nutrient solution, and the leaves were enriched in {sup 10}B and the stem in {sup 11}B relative to the xylem sap. Although at present, a mechanistic role for boron in plants is uncertain, potential fractionating mechanisms are discussed. (author)

Boron-isotope fractionation in plants

International Nuclear Information System (INIS)

Marentes, E.; Vanderpool, R.A.; Shelp, B.J.

1997-01-01

Naturally-occurring variations in the abundance of stable isotopes of carbon, nitrogen, oxygen, and other elements in plants have been reported and are now used to understand various physiological processes in plants. Boron (B) isotopic variation in several plant species have been documented, but no determination as to whether plants fractionate the stable isotopes of boron, 11 B and 10 B, has been made. Here, we report that plants with differing B requirements (wheat, corn and broccoli) fractionated boron. The whole plant was enriched in 11 B relative to the nutrient solution, and the leaves were enriched in 10 B and the stem in 11 B relative to the xylem sap. Although at present, a mechanistic role for boron in plants is uncertain, potential fractionating mechanisms are discussed. (author)

Phloem unloading and cell expansion in pea stems

International Nuclear Information System (INIS)

Schmalstig, J.G.; Cosgrove, D.J.

1989-01-01

Phloem unloading into elongating stems of dark-grown pea seedlings was greater in regions with higher relative growth rates. Phloem transport was monitored over 1 h by measuring accumulation of radiolabel from 14 C-sucrose added between the cotyledons. The apical hook and plumule and 8 mm of the growing region of an intact plant were sealed in a pressure chamber and the pressure was raised to stop elongation. Phloem unloading was inhibited in the pressurized zone of elongation and accelerated in the apical hook and plumule, with the result that the magnitude of phloem transport into the stem was unchanged. The results demonstrate a coupling between cell expansion and phloem unloading

Belowground Water Dynamics Under Contrasting Annual and Perennial Plant Communities in an Agriculturally-Dominated Landscape

Science.gov (United States)

Mora, G.; Asbjornsen, H.; Helmers, M. J.; Shepherd, G. W.

2005-12-01

The conversion from grasslands and forests to row-crops in the Midwest has affected soil water cycling because plant characteristics are one of the main parameters determining soil storage capacity, infiltration rates, and surface runoff. Little is known, however, about the extent of modification of soil water dynamics under different plant communities. To address this important issue, we are documenting soil water dynamics under contrasting perennial and annual plant communities in an agriculturally-dominated landscape. Measurements of soil moisture and depths of uptake of source water were obtained for six vegetative cover types (corn and soybean field, brome pasture, degraded savanna, restored savanna, and restored prairie) at the Neal Smith National Wildlife Refuge in Prairie City, Iowa. The depths of uptake of soil water were determined on the basis of oxygen isotope composition of soil water and stem water. Measurements were performed once a month during an entire growing season. Preliminary results indicate that soil water present under the different vegetation types show similar profiles with depth during the dry months. Soil water in the upper 5 cm is enriched in oxygen-18 by about 5 per mil relative to soil water at 100 cm. Our preliminary results also indicate that the isotopic composition of stem water from annual plants is typically higher by about 2 per mil relative to that of stem water from perennial plants during the dry period. Whereas the oxygen isotopic composition for corn stem water is -5.49 per mil, that for elm and oak stem water is -7.62 and -7.51 per mil, respectively. The higher isotope values for corn suggest that annual crop plants are withdrawing water from shallower soil horizons relative to perennial plants. Moreover, our preliminary data suggest lower moisture content in soil under annual plant cover. We propose that the presence of deeper roots in the perennial vegetation allows these plants to tap into deeper water sources when

Forage yield and nutritive value of Tanzania grass under nitrogen supplies and plant densities

Directory of Open Access Journals (Sweden)

Fabrício Paiva de Freitas

2012-04-01

Full Text Available The objective of this experiment was to evaluate the nitrogen and plant density influence on the yield, forage dissection and nutritive value of Tanzania grass (Panicum maximum Jacq.. The design was of completely randomized blocks with three replications in a factorial arrangement with four nitrogen levels (0, 80, 160 or 320 kg/ha N and three plant densities (9, 25 or 49 plants/m². The plots were cut at 25 cm from soil level when the canopy reached 95% of light interception. The total dry matter forage yield and dry matter forage yield per harvest increased linearly with the nitrogen fertilization. The leaf and stem yield had the same response. The senesced forage yield was quadratically influenced by the nitrogen. The stems ratio in the morphologic composition was high in the high nitrogen levels and in the low plant densities. The leaf:stem ratio showed high values in this trial, but it was increased in plots without nitrogen and high plant density. The pre-grazing height was reduced with the increase in plant density. The nutritive value was favored by the nitrogen fertilization, which increased the crude protein level and reduced neutral detergent fiber and lignin. These factors increased the leaf and stem in vitro digestibility of organic matter. Nitrogen fertilization increases the forage yield of Tanzania grass under rotational grazing. After the establishment, plant density has little influence on the Tanzania grass yield and its forage dissection. The harvest with 95% light interception improves the structure and nutritive value of Tanzania grass pastures.

Soil-to-plant transfer factors of trace and major elements in rice plant (Oryza Sativa) at Kalpakkam

International Nuclear Information System (INIS)

Sreedevi, K.R.; Rajaram, S.; Thulasi Brindha, J.; Venkataraman, S.; Hegde, A.G.

2011-01-01

The objective of this study was to evaluate the distribution of trace and major elements in rice plant (Oryza Sativa) which is the staple diet of the public at Kalpakkam. The transfer factor from soil to various parts of plant was also studied. Trace and major elements such as Fe, Mn, Zn, Co, Cu, Ni, Cr, Cd, Pb , Sr, K, Ca and Mg were selected based on their role in nutrition and also to study the behaviour of their radioactive counterparts. Among the trace elements Fe concentration was observed to be maximum in soil, the mean value of which was 18394 mg/kg dry wt. Cadmium concentration was observed to be minimum with the mean value of 2 mg/kg dry wt. The maximum and minimum concentration observed in the rice grain were due to Zn and Cd and the values were found to be 9 and 0.044 mg/kg dry wt, respectively. In the stem and leaves part the maximum and minimum concentration was due to Fe and Cd and the values were found to be 26.8 and 0.12 mg/kg dry wt. Similarly in the root part Fe and Cd concentrations were found to be maximum and minimum, respectively. Among the different parts of the rice plant, trace elements concentration in root was maximum and in stem and leaves major elements concentration was maximum. Transfer factor from soil to plant parts was computed. In general, the transfer factor was maximum in root, followed by stem and leaves and grain for trace elements. The transfer factor computed for whole rice plant was maximum for Zn and minimum for Sr which is a significant observation from radiological point of view. (author)

Diversity of Endophytic Fungi from Red Ginger (Zingiber officinale Rosc. Plant and Their Inhibitory Effect to Fusarium oxysporum Plant Pathogenic Fungi

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SIHEGIKO KANAYA

2013-09-01

Full Text Available Indonesia has been known as a country with high medicinal plant diversity. One of the most common medicinal plant from Indonesia is red ginger (Zingiber officinale Rosc.. Nevertheless, limited studies of endophytic fungi associated with these medicinal plants are hitherto available. The objectives of this research were to study the diversity of endophytic fungi on red ginger and to analyze their potential as a source of antifungal agent. All parts of plant organs such as leaf, rhizome, root, and stem were subjected for isolation. Fungal identification was carried out by using a combination of morphological characteristic and molecular analysis of DNA sequence generated from ITS rDNA region. Thirty endophytic fungi were successfully isolated from leaf, rhizome, root, and stem of red ginger plant. Antagonistic activity was tested against Fusarium oxysporum, a pathogenic fungus on plants, using an antagonistic assay. Based on this approach, the fungi were assigned as Acremonium macroclavatum, Beltraniella sp., Cochliobolus geniculatus and its anamorphic stage Curvularia affinis, Fusarium solani, Glomerella cingulata, and its anamorphic stage Colletotrichum gloeosporoides, Lecanicillium kalimantanense, Myrothecium verrucaria, Neonectria punicea, Periconia macrospinosa, Rhizopycnis vagum, and Talaromyces assiutensis. R. vagum was found specifically on root whereas C. affinis, L. kalimantanense, and M. verrucaria were found on stem of red ginger plant. A. macroclavatum was found specifically in red ginger plant’s organ which located under the ground, whereas C. affinis was found from shoot or organ which located above the ground. The antagonistic activity of isolated endophytic fungi against F. oxysporum varied with the inhibition value range from 1.4 to 68.8%. C. affinis (JMbt7, F. solani (JMd14, and G. cingulata (JMr2 had significantly high antagonistic activity with the value above 65%; and R. vagum (JMa4 and C. geniculatus (JMbt9 had

Development of electrical conductivity measurement technology for key plant physiological information using microneedle sensor

International Nuclear Information System (INIS)

Jeon, Eunyong; Lee, Junghoon; Choi, Seungyul; Yeo, Kyung-Hwan; Park, Kyoung Sub; Rathod, Mitesh L

2017-01-01

Impedance measurement is a widely used technique for monitoring ion species in various applications. In plant cultivation, the impedance system is used to measure the electrical conductivity (EC) of nutrient solutions. Recent research has shown that the quality and quantity of horticultural crops, e.g. tomato, can be optimized by controlling the salinity of nutrient solutions. However, understanding the detailed response of a plant to a nutrient solution is not possible until the fruit is fully grown or by sacrificing the stem. To overcome this issue, horticultural crop cultivation requires real-time monitoring of the EC inside the stem. Using this data, the growth model of a plant could be constructed, and the response of the plant to external environment determined. In this paper, we propose an implantable microneedle device equipped with a micro-patterned impedance measurement system for direct measurement of the EC inside the tomato stem. The fabrication process includes silicon-based steps such as microscale deposition, photolithography, and a deep etching process. Further, microscale fabrication enables all functional elements to fulfill the area budget and be very accurate with minimal plant invasion. A two-electrode geometry is used to match the measurement condition of the tomato stem. Real-time measurement of local sap condition inside the plant in which real-time data for tomato sap EC is obtained after calibration at various concentrations of standard solution demonstrate the efficacy of the proposed device. (paper)

Development of electrical conductivity measurement technology for key plant physiological information using microneedle sensor

Science.gov (United States)

Jeon, Eunyong; Choi, Seungyul; Yeo, Kyung-Hwan; Park, Kyoung Sub; Rathod, Mitesh L.; Lee, Junghoon

2017-08-01

Impedance measurement is a widely used technique for monitoring ion species in various applications. In plant cultivation, the impedance system is used to measure the electrical conductivity (EC) of nutrient solutions. Recent research has shown that the quality and quantity of horticultural crops, e.g. tomato, can be optimized by controlling the salinity of nutrient solutions. However, understanding the detailed response of a plant to a nutrient solution is not possible until the fruit is fully grown or by sacrificing the stem. To overcome this issue, horticultural crop cultivation requires real-time monitoring of the EC inside the stem. Using this data, the growth model of a plant could be constructed, and the response of the plant to external environment determined. In this paper, we propose an implantable microneedle device equipped with a micro-patterned impedance measurement system for direct measurement of the EC inside the tomato stem. The fabrication process includes silicon-based steps such as microscale deposition, photolithography, and a deep etching process. Further, microscale fabrication enables all functional elements to fulfill the area budget and be very accurate with minimal plant invasion. A two-electrode geometry is used to match the measurement condition of the tomato stem. Real-time measurement of local sap condition inside the plant in which real-time data for tomato sap EC is obtained after calibration at various concentrations of standard solution demonstrate the efficacy of the proposed device.

In-vitro antibacterial activity of selected medicinal plants from ...

African Journals Online (AJOL)

Background: Current strategies to overcome the global problem of antimicrobial resistance include research in finding new and innovative antimicrobials from plants. This study was carried out to determine the antibacterial activity of plant extracts of Olea africana stem-bark, Psidium guajava leaves, Vernonia amygdalina ...

Transgene silencing of sucrose synthase in alfalfa (Medicago sativa L.) stem vascular tissue suggests a role for invertase in cell wall cellulose synthesis.

Science.gov (United States)

Samac, Deborah A; Bucciarelli, Bruna; Miller, Susan S; Yang, S Samuel; O'Rourke, Jamie A; Shin, Sanghyun; Vance, Carroll P

2015-12-01

Alfalfa (Medicago sativa L.) is a widely adapted perennial forage crop that has high biomass production potential. Enhanced cellulose content in alfalfa stems would increase the value of the crop as a bioenergy feedstock. We examined if increased expression of sucrose synthase (SUS; EC 2.4.1.13) would increase cellulose in stem cell walls. Alfalfa plants were transformed with a truncated alfalfa phosphoenolpyruvate carboxylase gene promoter (PEPC7-P4) fused to an alfalfa nodule-enhanced SUS cDNA (MsSUS1) or the β-glucuronidase (GUS) gene. Strong GUS expression was detected in xylem and phloem indicating that the PEPC7-P4 promoter was active in stem vascular tissue. In contrast to expectations, MsSUS1 transcript accumulation was reduced 75-90 % in alfalfa plants containing the PEPC7-P4::MsSUS1 transgene compared to controls. Enzyme assays indicated that SUS activity in stems of selected down-regulated transformants was reduced by greater than 95 % compared to the controls. Although SUS activity was detected in xylem and phloem of control plants by in situ enzyme assays, plants with the PEPC7-P4::MsSUS1 transgene lacked detectable SUS activity in post-elongation stem (PES) internodes and had very low SUS activity in elongating stem (ES) internodes. Loss of SUS protein in PES internodes of down-regulated lines was confirmed by immunoblots. Down-regulation of SUS expression and activity in stem tissue resulted in no obvious phenotype or significant change in cell wall sugar composition. However, alkaline/neutral (A/N) invertase activity increased in SUS down-regulated lines and high levels of acid invertase activity were observed. In situ enzyme assays of stem tissue showed localization of neutral invertase in vascular tissues of ES and PES internodes. These results suggest that invertases play a primary role in providing glucose for cellulose biosynthesis or compensate for the loss of SUS1 activity in stem vascular tissue.

Herbicides effect on the nitrogen fertilizer assimilation by sensitive plants

International Nuclear Information System (INIS)

Ladonin, V.F.; Samojlov, L.N.

1976-01-01

It has been established in studying the effect of herbicides on pea plants that the penetration of the preparations into the tissues of leaves and stems results in a slight increase of the rate of formation of dry substance in the leaves of the treated plants within 24 hours after treatment as compared with control, whereas in the last period of the analysis the herbicides strongly inhibit the formation of dry substance in leaves. The applied herbicide doses have resulted in drastic changes of the distribution of the plant-assimilated nitrogen between the protein and non-protein fractions in the leaves and stems of pea. When affected by the studied herbicides, the fertilizer nitrogen supply to the pea plants changes and the rate of the fertilizer nitrogen assimilation by the plants varies noticeably. The regularities of the fertilizer nitrogen inclusion in the protein and non-protein nitrogen compounds of the above-ground pea organs have been studied

Determination of coefficient defining leaf area development in different genotypes, plant types and planting densities in peanut (Arachis hypogeae L.).

Science.gov (United States)

Halilou, Oumarou; Hissene, Halime Mahamat; Clavijo Michelangeli, José A; Hamidou, Falalou; Sinclair, Thomas R; Soltani, Afshin; Mahamane, Saadou; Vadez, Vincent

2016-12-01

Rapid leaf area development may be attractive under a number of cropping conditions to enhance the vigor of crop establishment and allow rapid canopy closure for maximizing light interception and shading of weed competitors. This study was undertaken to determine (1) if parameters describing leaf area development varied among ten peanut ( Arachis hypogeae L.) genotypes grown in field and pot experiments, (2) if these parameters were affected by the planting density, and (3) if these parameters varied between Spanish and Virginia genotypes. Leaf area development was described by two steps: prediction of main stem number of nodes based on phyllochron development and plant leaf area dependent based on main stem node number. There was no genetic variation in the phyllochron measured in the field. However, the phyllochron was much longer for plants grown in pots as compared to the field-grown plants. These results indicated a negative aspect of growing peanut plants in the pots used in this experiment. In contrast to phyllochron, there was no difference in the relationship between plant leaf area and main stem node number between the pot and field experiments. However, there was genetic variation in both the pot and field experiments in the exponential coefficient (PLAPOW) of the power function used to describe leaf area development from node number. This genetic variation was confirmed in another experiment with a larger number of genotypes, although possible G × E interaction for the PLAPOW was found. Sowing density did not affect the power function relating leaf area to main stem node number. There was also no difference in the power function coefficient between Spanish and Virginia genotypes. SSM (Simple Simulation model) reliably predicted leaf canopy development in groundnut. Indeed the leaf area showed a close agreement between predicted and observed values up to 60000 cm 2  m -2 . The slightly higher prediction in India and slightly lower prediction in

Use of sediment CO2 by submersed rooted plants

DEFF Research Database (Denmark)

Winkel, Anders; Borum, Jens

2009-01-01

freshwater plants with different morphology and growth characteristics (Lobelia dortmanna, Lilaeopsis macloviana, Ludwigia repens, Vallisneria americana and Hydrocotyle verticillata) are able to support photosynthesis supplied by uptake of CO2 from the sediment. Methods: Gross photosynthesis was measured......Background and Aims: Submersed plants have different strategies to overcome inorganic carbon limitation. It is generally assumed that only small rosette species (isoetids) are able to utilize the high sediment CO2 availability. The present study examined to what extent five species of submersed......, the shoot to root ratio on an areal basis was the single factor best explaining variability in the importance of sediment CO2. For Ludwigia, diffusion barriers limited uptake or transport from roots to stems and transport from stems to leaves. Conclusions: Submersed plants other than isoetids can utilize...

Evidence of correlated evolution and adaptive differentiation of stem and leaf functional traits in the herbaceous genus, Helianthus.

Science.gov (United States)

Pilote, Alex J; Donovan, Lisa A

2016-12-01

Patterns of plant stem traits are expected to align with a "fast-slow" plant economic spectrum across taxa. Although broad patterns support such tradeoffs in field studies, tests of hypothesized correlated trait evolution and adaptive differentiation are more robust when taxa relatedness and environment are taken into consideration. Here we test for correlated evolution of stem and leaf traits and their adaptive differentiation across environments in the herbaceous genus, Helianthus. Stem and leaf traits of 14 species of Helianthus (28 populations) were assessed in a common garden greenhouse study. Phylogenetically independent contrasts were used to test for evidence of correlated evolution of stem hydraulic and biomechanical properties, correlated evolution of stem and leaf traits, and adaptive differentiation associated with source habitat environments. Among stem traits, there was evidence for correlated evolution of some hydraulic and biomechanical properties, supporting an expected tradeoff between stem theoretical hydraulic efficiency and resistance to bending stress. Population differentiation for suites of stem and leaf traits was found to be consistent with a "fast-slow" resource-use axis for traits related to water transport and use. Associations of population traits with source habitat characteristics supported repeated evolution of a resource-acquisitive "drought-escape" strategy in arid environments. This study provides evidence of correlated evolution of stem and leaf traits consistent with the fast-slow spectrum of trait combinations related to water transport and use along the stem-to-leaf pathway. Correlations of traits with source habitat characteristics further indicate that the correlated evolution is associated, at least in part, with adaptive differentiation of Helianthus populations among native habitats differing in climate. © 2016 Botanical Society of America.

Effect of BAP, ethrel and stem girdling on growth and partitioning of photosynthates in Y-shaped mungbean

International Nuclear Information System (INIS)

Panwar, J.D.S.; Abbas, S.; Sita Ram; Sirohi, G.S.

1988-01-01

During early vegetative growth, pots grown mungbean (Vigna radiata (L) Wilczek cv. Pusa 105) were forced to develop a Y-shaped stem consisting of two symmetrical branches. At preflowering stage, the plants were treated with 6-benzyl amino purine (BAP-20 ppm) and ethrel (500 ppm). Stem girdling was also done just below the junction of the two symmetrical branches and hormonal application (BAP) was done on one of the branches and its effect was observed on other branch of the same plant. Suitable controls were kept. BAP delayed the leaf senescence, enhanced photosynthetic rate and its duration on the treated as well as untreated leaf, whereas ethrel enhanced leaf senescence, reduced photosynthetic rate and its duration. 14 C studies indicated that the translocation of photosynthates was diverted differentially to other plant parts through hormonal application. Girdling on main stem affected the remote effects of hormones and about 98% 14 C remained on the applied branch itself indicating that growth regulators showed their effect on the other branch through roots only. (author). 4 refs., 4 tabs

Effect of planting density and cutting frequency on forage and grain yields of kochia (Kochia scoparia under saline water irrigation

Directory of Open Access Journals (Sweden)

mseou ziyaeii

2009-06-01

Full Text Available AField experiment was conducted at Research Farms of Center of Excellence for Special Crops, Ferdowsi University of Mashhad, Mashhad, Iran, in 2006 to evaluate the effect of planting density on forage and grain yield of kochia (Kochia scoparia. Experimental design was a randomized complete block with split-plot arrangement of treatments,with three replications, where different planting densities (10, 20, 30 and 40 plant m-2 were assigned to main plots and number of cutting (including a single cutting, two cutting and no cutting i.e. allowing the crop to grow until maturity allocated to sub-plots. At each harvest date (cutting the biological yield, leaf and stem dry weight, plant height, number of branches and the individual plant biomass were measured. Grain yield and thousand seed weight were also determined at the end of growing season. Result showed the highest biological yield and leaf and stem dry weights for kochia obtaind at 30 plant m-2. The total biomass, leaf and stem dry weights, plant height, number of branches were greater for the first cutting as compared to the second cutting. Planting density and cutting number interacted to affect the leaf dry weight. At physiological maturity stage there were no significant differences among planting densities for plant height and number of branches. The best planting density, in terms of biomass production and leaf and stem dry weight, was found as 30 plant m-2, while for grain production a planting density of 20 plant m-2 could be recommended. Key words: Kochia, planting density, sward, biological yield, grain production.

Variation in coumarin accumulation by stem age in Dendrobium ...

African Journals Online (AJOL)

STORAGESEVER

2009-03-06

Mar 6, 2009 ... stem sample of 1, 2 and 3-year-old were observed by laser scanning confocal microscope. ANOVA and ... mainly in vascular bundle and its outer fiber cell wall, ground tissue cell wall and nearby, wall of ... Wrigley's (1960) extract from the plant ..... (2006). Surface functionalization of gold nanoparticles using.

VARIABILITY OF LENGTH OF STEM OF DETERMINATE AND INDETERMINATE CULTIVARS OF COMMON VETCH (VICIA SATIVA L. SSP. SATIVA AND ITS IMPACT ON SELECTED CROPPING FEATURES

Directory of Open Access Journals (Sweden)

Jadwiga ANDRZEJEWSKA

2006-12-01

Full Text Available In the years 2001 and 2002, the study was conducted in six experiments in order to examine the conditioning of the length of stem variability and its impact on cropping features of determinate and indeterminate cultivars of common vetch. Rainfall in June and July as well as during the whole growing season was positively correlated with length of stem, but negatively correlated with seed yield, to a larger extent in the group of indeterminate cultivars than in the determinate one. Duration of blooming stage, length of stem, and seed yield showed the largest variability in both groups. Increase in length of stem of plants of indeterminate cultivars led to the delay in maturation, to less even maturation, and to the decrease in the thousand seed weight and seed yield. Increase in length of stem of plants of determinate cultivars delayed reaching the phase of technical maturation and decreased evenness of plant maturation. Determinate growth of common vetch did not lead to the reduction of lodging.

Overexpression of Arabidopsis VIT1 increases accumulation of iron in cassava roots and stems.

Science.gov (United States)

Narayanan, Narayanan; Beyene, Getu; Chauhan, Raj Deepika; Gaitán-Solis, Eliana; Grusak, Michael A; Taylor, Nigel; Anderson, Paul

2015-11-01

Iron is extremely abundant in the soil, but its uptake in plants is limited due to low solubility in neutral or alkaline soils. Plants can rely on rhizosphere acidification to increase iron solubility. AtVIT1 was previously found to be involved in mediating vacuolar sequestration of iron, which indicates a potential application for iron biofortification in crop plants. Here, we have overexpressed AtVIT1 in the starchy root crop cassava using a patatin promoter. Under greenhouse conditions, iron levels in mature cassava storage roots showed 3-4 times higher values when compared with wild-type plants. Significantly, the expression of AtVIT1 showed a positive correlation with the increase in iron concentration of storage roots. Conversely, young leaves of AtVIT1 transgenic plants exhibit characteristics of iron deficiency such as interveinal chlorosis of leaves (yellowing) and lower iron concentration when compared with the wild type plants. Interestingly, the AtVIT1 transgenic plants showed 4 and 16 times higher values of iron concentration in the young stem and stem base tissues, respectively. AtVIT1 transgenic plants also showed 2-4 times higher values of iron content when compared with wild-type plants, with altered partitioning of iron between source and sink tissues. These results demonstrate vacuolar iron sequestration as a viable transgenic strategy to biofortify crops and to help eliminate micronutrient malnutrition in at-risk human populations. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Antifungal activity of methanolic extracts of some indigenous plants against common soil-borne fungi

International Nuclear Information System (INIS)

Tuba, T.; Abid, M.; Shaukat, S. S.; Shaikh, A.

2016-01-01

Present study was conducted to evaluate the fungicidal property of methanolic extracts of some indigenous plants of Karachi such as Hibiscus rosa-sinensis (leaves), The spesia populnea (leaves, stem and fruit), Withania somnifera (leaves and stem), Solanum surattense (shoot) and Melia azedarach (fruit) against common soil-borne phytopathogens viz., Macrophomina phaseolina, Rhizoctonia solani and Fusarium oxysporum by using food poison technique. Among the eight methanolic extracts of tested parts of plants, seven showed antifungal activity, of which T. populnea leaves and S. surattense shoots inhibited growth of all three test pathogens. Leaves of H. rosa-sinensis did not exhibit antifungal activity. T. populnea (leaves and stem), W. somnifera (stem) and M. azedarach (fruit) suppressed growth of Rhizoctonia solani by 100 percent. T. populnea leaves and M. azedarach fruit inhibited growth of M. phaseolina by 100 percent and 82 percent, respectively T. populnea leaves inhibited 99 percent mycelial growth of F. oxysporum. It is concluded that the methanolic extracts of the tested indigenous plants contain natural fungicidal compounds, which can be used for the control of common soil-borne pathogens. (author)

Expression of a Petunia inflata pectin methyl esterase in Solanum tuberosum L. enhances stem elongation and modifies cation distribution.

Science.gov (United States)

Pilling, J; Willmitzer, L; Fisahn, J

2000-02-01

Transgenic potato (Solanum tuberosum L.) plants were constructed with a Petunia inflata-derived cDNA encoding a pectin methyl esterase (PME; EC 3.1.1.11) in sense orientation under the control of the cauliflower mosaic virus 35S promoter. The PME activity was elevated in leaves and tubers of the transgenic lines but slightly reduced in apical segments of stems from mature plants. Stem segments from the base of juvenile PME-overexpressing plants did not differ in PME activity from the control, whereas in apical parts PME was less active than in the wild-type. During the early stages of development stems of these transgenic plants elongated more rapidly than those of the wild-type. Further evidence that overexpression of a plant-derived PME has an impact on plant development is based on modifications of tuber yield, which was reduced in the transgenic lines. Cell walls from transgenic tubers showed significant differences in their cation-binding properties in comparison with the wild-type. In particular, cell walls displayed increased affinity for sodium and calcium, while potassium binding was constant. Furthermore, the total ion content of transgenic potatoes was modified. Indications of PME-mediated differences in the distribution of ions in transgenic plants were also obtained by monitoring relaxations of the membrane potential of roots subsequent to changes in the ionic composition of the bathing solution. However, no effects on the chemical structure of pectin from tuber cell walls could be detected.

Activities of fructan- and sucrose-metabolizing enzymes in wheat stems subjected to water stress during grain filling.

Science.gov (United States)

Yang, Jianchang; Zhang, Jianhua; Wang, Zhiqing; Zhu, Qingsen; Liu, Lijun

2004-12-01

This study investigated if a controlled water deficit during grain filling of wheat (Triticum aestivum L.) could accelerate grain filling by facilitating the remobilization of carbon reserves in the stem through regulating the enzymes involved in fructan and sucrose metabolism. Two high lodging-resistant wheat cultivars were grown in pots and treated with either a normal (NN) or high amount of nitrogen (HN) at heading time. Plants were either well-watered (WW) or water-stressed (WS) from 9 days post anthesis until maturity. Leaf water potentials markedly decreased at midday as a result of water stress but completely recovered by early morning. Photosynthetic rate and zeatin + zeatin riboside concentrations in the flag leaves declined faster in WS plants than in WW plants, and they decreased more slowly with HN than with NN when soil water potential was the same, indicating that the water deficit enhanced, whereas HN delayed, senescence. Water stress, both at NN and HN, facilitated the reduction in concentration of total nonstructural carbohydrates (NSC) and fructans in the stems but increased the sucrose level there, promoted the re-allocation of pre-fixed (14)C from the stems to grains, shortened the grain-filling period, and accelerated the grain-filling rate. Grain weight and grain yield were increased under the controlled water deficit when HN was applied. Fructan exohydrolase (FEH; EC 3.2.1.80) and sucrose phosphate synthase (SPS; EC 2.4.1.14) activities were substantially enhanced by water stress and positively correlated with the total NSC and fructan remobilization from the stems. Acid invertase (EC 3.2.1.26) activity was also enhanced by the water stress and associated with the change in fructan concentration, but not correlated with the total NSC remobilization and (14)C increase in the grains. Sucrose:sucrose fructosyltransferase (EC 2.4.1.99) activity was inhibited by the water stress and negatively correlated with the remobilization of carbon reserves

Adsorption of heavy metals ions on portulaca oleracea plants

International Nuclear Information System (INIS)

Naqvi, R.R.

2005-01-01

The aim of this study is to report the ability of portulaca oleracea (Fershi in Urdu) biomass grown in uncontaminated soils to adsorb or uptake lead, cadmium, arsenic, cobalt and copper from aqueous solutions. In order to help understand the metal binding mechanism, laboratory experiments performance to determine optimal binding, and binding capacity for each of the above mentioned metals. These experiments were carried out for the mass of crushed portulaca stems. Portulaca is a plant that grows abundantly in temperature climate in the area of Quetta Balochistan. It has reddish stem and thick succulent leaves. This plant has been found to be good adsorbent for heavy metals ions. (author)

Stem cells in dentistry--part I: stem cell sources.

Science.gov (United States)

Egusa, Hiroshi; Sonoyama, Wataru; Nishimura, Masahiro; Atsuta, Ikiru; Akiyama, Kentaro

2012-07-01

Stem cells can self-renew and produce different cell types, thus providing new strategies to regenerate missing tissues and treat diseases. In the field of dentistry, adult mesenchymal stem/stromal cells (MSCs) have been identified in several oral and maxillofacial tissues, which suggests that the oral tissues are a rich source of stem cells, and oral stem and mucosal cells are expected to provide an ideal source for genetically reprogrammed cells such as induced pluripotent stem (iPS) cells. Furthermore, oral tissues are expected to be not only a source but also a therapeutic target for stem cells, as stem cell and tissue engineering therapies in dentistry continue to attract increasing clinical interest. Part I of this review outlines various types of intra- and extra-oral tissue-derived stem cells with regard to clinical availability and applications in dentistry. Additionally, appropriate sources of stem cells for regenerative dentistry are discussed with regard to differentiation capacity, accessibility and possible immunomodulatory properties. Copyright © 2012 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Micropropagation of Origanum acutidens (HAND.-MAZZ.) IETSWAART using stem node explants.

Science.gov (United States)

Yildirim, Mehmet Ugur

2013-01-01

Origanum acutidens (HAND.-MAZZ.) IETSWAART is a promising ornamental plant that can be widely used in landscape management. It is endemic to Eastern Anatolian region of Turkey. Tissue culture has not been used to micropropagate it. The study reports stem node explants from one-week-old seedlings of the plant for successful micropropagation. The stem nodes were cultured on MS medium containing 0.6, 1.2, 1.8, and 2.4 mg/L BAP with 0.2 mg/L NAA. Visible effects of culture media on shoot proliferation were recorded. Shoot regeneration rate was maximum on MS medium containing 1.80 mg/L BAP-0.2 mg/L NAA. The micropropagated shoots were rooted on MS medium containing 0.2 mg/L NAA. All microrooted plantlets survived during acclimatisation on peat moss. It was concluded that O. acutidens can be successfully micropropagated under in vitro conditions.

Endophytic Ability of Different Isolates of Entomopathogenic Fungi Beauveria bassiana (Balsamo) Vuillemin in Stem and Leaf Tissues of Maize (Zea mays L.).

Science.gov (United States)

Renuka, S; Ramanujam, B; Poornesha, B

2016-06-01

The present study was conducted to examine the ability of six promising indigenous isolates of Beauveria bassiana (NBAII-Bb-5a, 7, 14, 19, 23 and 45) as an endophyte in maize stem and leaf tissues. Maize seedlings (var. Nithyashree) were inoculated with conidial suspensions and were examined for endophytic establishment in leaf and stems at different intervals during 15-90 days after treatment. All six isolates showed colonization in stem and leaf tissues with varying abilities of colonization and persistence. The mean percent colonization ranged from 7.41 to 20.37 % in older stem tissues and 3.70 to 21.29 % in young stem tissues and in leaf, it ranged from 6.46 to 27.78 % in older leaf tissues and 11.11 to 26.85 % in young leaf tissues. Among six isolates tested, Bb-23 isolate recorded the maximum mean colonization in older stem (20.37 %), older leaf (27.78 %) and in young stem (21.29 %). Bb-5a isolate showed maximum mean colonization in young leaf tissues (26.85 %). Persistence of inoculated fungal isolates decreased with increase in age of the plant. No physical symptoms of damage were observed in any of the B. bassiana treated plants. No colonization of B. bassiana was observed in the untreated control maize plants. The results obtained in plating and PCR techniques were similar with regard to the confirmation of endophytic establishment of B. bassiana. This study indicated the possibility of using B. bassiana as an endophyte in maize for management of maize stem borer, Chilo partellus.

Ethanol stem bark extract of Rauwolfia vomitoria ameliorates MPTP ...

African Journals Online (AJOL)

Methods: The Parkinson's disease was induced in rats by a single intraperitoneal (IP) injection of MPTP. After 72h of induction, the young adult male rats were treated with oral administration of stem bark ethanol extract of the plant daily for 2 weeks. The blood chemistry, antioxidant markers and brain dopamine levels were ...

Cadmium tolerance and accumulation characteristics of mature flax, cv. Hermes: Contribution of the basal stem compared to the root

Energy Technology Data Exchange (ETDEWEB)

Douchiche, Olfa, E-mail: olfa.douchiche@hotmail.fr [Laboratory Glyco-MEV EA 4358, IFRMP 23, University of Rouen, 76821 Mont Saint Aignan Cedex (France); Laboratory Biologie et Physiologie Cellulaires Vegetales, Department of Biology, University of Tunis, 1060 Tunis (Tunisia); Chaiebi, Wided [Laboratory Biologie et Physiologie Cellulaires Vegetales, Department of Biology, University of Tunis, 1060 Tunis (Tunisia); Morvan, Claudine, E-mail: claudine.morvan@univ-rouen.fr [Laboratory PBS-UMR 6270 CNRS, FR 3038, University of Rouen, 76821 Mont Saint Aignan Cedex (France)

2012-10-15

Highlights: Black-Right-Pointing-Pointer Cd accumulated in stem bottom part exceeded the defined hyperaccumulator threshold. Black-Right-Pointing-Pointer No toxic symptoms occurred and TI of all growth parameters ranged between 0.7 and 1. Black-Right-Pointing-Pointer The high level of Zn, Mn and Cu may contribute to the absence of chlorosis in stem. Black-Right-Pointing-Pointer Cd/Ca synergistic effect observed in the stem may alleviate Cd toxicity. Black-Right-Pointing-Pointer Hermes variety accumulated more Cd than the other flax varieties ever described. - Abstract: The potential of mature flax plants (cv. Hermes) to tolerate and accumulate cadmium (Cd) was studied to determine which part of the plant would be the key organ for phytoremediation purposes. After 4 month-growth on sand substrate containing 0.1 mM Cd in a greenhouse, the roots and stems were separated and the stems were divided into three parts. The effects of Cd were studied on growth parameters, histology and mineral nutrition. No visible toxic symptoms were observed. Tolerance-index values calculated from growth parameters and nutrients remained relatively high, allowing the development of the plant until maturity and formation of seeds. The roots and bottom stem accumulated the highest quantity of Cd (750 and 360 mg/kg dry matter), values which largely exceeded the threshold defined for hyperaccumulators. On the other hand, basal stem had a high bioconcentration factor (BCF = 32) and translocation factor TF Prime (2.5) but a low TF (0.5), indicating that this basal part would play a major role in phytoremediation (phytostabilization rather than phytorextraction). Therefore, the high tolerance to Cd and accumulation capacity make possible to grow Hermes flax on Cd-polluted soils.

Stem mortality in surface fires: Part II, experimental methods for characterizing the thermal response of tree stems to heating by fires

Science.gov (United States)

D. M. Jimenez; B. W. Butler; J. Reardon

2003-01-01

Current methods for predicting fire-induced plant mortality in shrubs and trees are largely empirical. These methods are not readily linked to duff burning, soil heating, and surface fire behavior models. In response to the need for a physics-based model of this process, a detailed model for predicting the temperature distribution through a tree stem as a function of...

A Novel Gibberellin-Induced Gene from Rice and Its Potential Regulatory Role in Stem Growth1

Science.gov (United States)

van der Knaap, Esther; Kim, Jeong Hoe; Kende, Hans

2000-01-01

Os-GRF1 (Oryza sativa-GROWTH-REGULATING FACTOR1) was identified in a search for genes that are differentially expressed in the intercalary meristem of deepwater rice (Oryza sativa L.) internodes in response to gibberellin (GA). Os-GRF1 displays general features of transcription factors, contains a functional nuclear localization signal, and has three regions with similarities to sequences in the database. One of these regions is similar to a protein interaction domain of SWI2/SNF2, which is a subunit of a chromatin-remodeling complex in yeast. The two other domains are novel and found only in plant proteins of unknown function. To study its role in plant growth, Os-GRF1 was expressed in Arabidopsis. Stem elongation of transformed plants was severely inhibited, and normal growth could not be recovered by the application of GA. Our results indicate that Os-GRF1 belongs to a novel class of plant proteins and may play a regulatory role in GA-induced stem elongation. PMID:10712532

Accumulation and distribution of elements in plants (paprika)

Energy Technology Data Exchange (ETDEWEB)

Karimian-Teherani, D.; Altmann, H.; Wallisch, G. (Oesterreichisches Forschungszentrum Seibersdorf G.m.b.H. Inst. fuer Biologie); Kiss, I. (Koezponti Elelmiszeripari Kutato Intezet, Budapest (Hungary)); Kapeller, K. (Zoeldsegtermesztesi Kutatointezet, Kalocsa (Hungary). Paprikakutato Allomas)

1983-01-01

Various samples of Hungarian paprika plant (leaf, stem, root, fruit with 20% seeds, fruit without seeds) and corresponding soils were analyzed for their Br, As, K, Mn, Cr content by neutron activation analysis and for Hg by flameless atomic absorption spectrometry. The statistical analysis showed no significant differences in the content of trace elements (Br, As, Zn, Hg, Mn) in leaves, stems and roots. The content of K in stems and leaves decreased significantly in general after three months. The content of Cr in roots and stems increased significantly after three months. In most cases, the increase of the seed content of the samples tended to reduce their K, Mn, Br contents, but Zn, As, Cr, Hg contents remained unchanged.

Micropropagation of Araucaria excelsa R. Br. var. glauca Carrière from orthotropic stem explants.

Science.gov (United States)

Sarmast, Mostafa Khoshhal; Salehi, Hassan; Khosh-Khui, Morteza

2012-07-01

The objectives of the present work were in vitro propagation of Araucaria excelsa R. Br. var. glauca Carrière (Norfolk Island pine) with focus on the evaluation of the mean number of shoots per explant (MNS/E) and mean length of shoots per explants (MLS/E) produced by different parts of the orthotropic stem of A. excelsa R. Br. var. glauca in response to plant growth regulators. Norfolk Island pine axillary meristems responded very well to the 2-iso-pentenyl adenine (2iP) and thidiazuron (TDZ) levels. Explants taken from stem upper segments in the media containing 2iP had a higher MNS/E (3.47) and MLS/E (6.27 mm) in comparison to those taken from stem lower segments, which were 0.71 and 0.51 mm, respectively. Using 0.045 μM TDZ in the MS medium not only resulted in 4.60 MNS/E with 7.08 mm MLS/E but proliferated shoots showed a good performance as well. Investigating the best position of stem explant on mother plant as well as the best concentrations of growth regulators were performed which were useful for efficient micropropagation of this plant. Thirty three percent of explants were rooted in the MS medium containing 3 % sucrose, supplemented with 7.5 μM of both NAA and IBA for 2 weeks before transferring to a half strength MS medium without any growth regulator. Plantlets obtained were acclimatized and transferred to the greenhouse with less than 20 % mortality. This procedure considered the first successful report for regeneration and acclimatization of A. excelsa R. Br. var. glauca plantlet through main stem explants.

Anatomical features of pepper plants (Capsicum annuum L.) grown under red light-emitting diodes supplemented with blue or far-red light

Science.gov (United States)

Schuerger, A. C.; Brown, C. S.; Stryjewski, E. C.

1997-01-01

Pepper plants (Capsicum annuum L. cv., Hungarian Wax) were grown under metal halide (MH) lamps or light-emitting diode (LED) arrays with different spectra to determine the effects of light quality on plant anatomy of leaves and stems. One LED (660) array supplied 90% red light at 660 nm (25nm band-width at half-peak height) and 1% far-red light between 700-800nm. A second LED (660/735) array supplied 83% red light at 660nm and 17% far-red light at 735nm (25nm band-width at half-peak height). A third LED (660/blue) array supplied 98% red light at 660nm, 1% blue light between 350-550nm, and 1% far-red light between 700-800nm. Control plants were grown under broad spectrum metal halide lamps. Plants were gron at a mean photon flux (300-800nm) of 330 micromol m-2 s-1 under a 12 h day-night photoperiod. Significant anatomical changes in stem and leaf morphologies were observed in plants grown under the LED arrays compared to plants grown under the broad-spectrum MH lamp. Cross-sectional areas of pepper stems, thickness of secondary xylem, numbers of intraxylary phloem bundles in the periphery of stem pith tissues, leaf thickness, numbers of choloplasts per palisade mesophyll cell, and thickness of palisade and spongy mesophyll tissues were greatest in peppers grown under MH lamps, intermediate in plants grown under the 660/blue LED array, and lowest in peppers grown under the 660 or 660/735 LED arrays. Most anatomical features of pepper stems and leaves were similar among plants grown under 660 or 660/735 LED arrays. The effects of spectral quality on anatomical changes in stem and leaf tissues of peppers generally correlate to the amount of blue light present in the primary light source.

A Preliminary Study of Banana Stem Juice as a Plant-Based Coagulant for Treatment of Spent Coolant Wastewater

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Habsah Alwi

2013-01-01

Full Text Available The effectiveness of banana stem juice as a natural coagulant for treatment of spent coolant wastewater was investigated . Three main parameters were studied, namely, chemical oxygen demand (COD, suspended solids (SSs, and turbidity of effluent. Coagulation experiments using jar test were performed with a flocculation system where the effects of spent coolant wastewater pH as well as banana stem juice dosage on coagulation effectiveness were examined. The highest recorded COD, SS, and turbidity removal percentages by banana stem juice were 80.1%, 88.6%, and 98.5%, respectively, observed for effluent at pH 7 using 90 mL dosage. The inulin concentration in the banana stem was examined to be 1.22016 mg/mL. It could be concluded that banana stem juice showed tremendous potential as a natural coagulant for water treatment purposes and could be applied in the pretreatment stage of Malaysian spent coolant wastewater prior to secondary treatment.

Increasing student success in STEM through geosciences based GIS curriculum, interdisciplinary project based learning, and specialized STEM student services

Science.gov (United States)

Cheung, W.

2012-12-01

Under the auspices of the National Science Foundation's Advanced Technological Education Grant and the Department of Education's Title V/HSI Grant, Palomar College students from a variety of disciplines have not only been exposed to the high growth field of geospatial technologies, but have also been exposed to the geosciences and regional environmental issues in their GIS courses. By integrating introductory Physical Geography topics such as liquefaction, subsidence, ozone depletion, plate tectonics, and coastal processes in the introductory GIS curriculum, GIS students from fields ranging from Archaeology to Zoology were exposed to basic geosciences theories in a series of hands-on interactive exercises, while gaining competency in geospatial technologies. Additionally, as students undertake interdisciplinary service learning projects under the supervision of experts in the private, governmental, and nonprofit sectors, students were introduced to the STEM workplace, forged invaluable professional connections, applied their classroom knowledge to advance research (e.g. analyzing migration patterns of cephalopod), and analyzed regional environmental issues (e.g. distribution of invasive plants in state natural preserves). In order to further the retention and completion of students in GIS, Earth Science, and other STEM courses, a STEM Student Learning Center was constructed, whereby students can receive services such as supplemental instruction, walk-in tutoring, STEM counseling and transfer advising, as well as faculty and peer mentoring.

Application of Hyperspectral Imaging to Detect Sclerotinia sclerotiorum on Oilseed Rape Stems

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Wenwen Kong

2018-01-01

Full Text Available Hyperspectral imaging covering the spectral range of 384–1034 nm combined with chemometric methods was used to detect Sclerotinia sclerotiorum (SS on oilseed rape stems by two sample sets (60 healthy and 60 infected stems for each set. Second derivative spectra and PCA loadings were used to select the optimal wavelengths. Discriminant models were built and compared to detect SS on oilseed rape stems, including partial least squares-discriminant analysis, radial basis function neural network, support vector machine and extreme learning machine. The discriminant models using full spectra and optimal wavelengths showed good performance with classification accuracies of over 80% for the calibration and prediction set. Comparing all developed models, the optimal classification accuracies of the calibration and prediction set were over 90%. The similarity of selected optimal wavelengths also indicated the feasibility of using hyperspectral imaging to detect SS on oilseed rape stems. The results indicated that hyperspectral imaging could be used as a fast, non-destructive and reliable technique to detect plant diseases on stems.

Rice stem borers in Malaya. A proposal to use mutation breeding for their control

Energy Technology Data Exchange (ETDEWEB)

Vohra, F C [University of Malaya, Kuala Lumpur (Malaysia)

1970-03-01

. Various factors pertaining to the morphology, physiology and chemical nature of the rice plant are possibly responsible for the stem borer resistance. Carefully planned experiments have to evaluate their contribution to resistance before successful breeding programs can be undertaken. A wild species of rice in Malaya, Oryza ridleyi Hook. is said to be highly resistant. Similarly, several cultivated varieties are claimed to offer considerable resistance, but none of them can be recommended for commercial planting because of unsatisfactory yield, grain size and appearance, and nutrient and cooking value. Therefore, in order to develop a valuable resistant variety one would have to improve all the above characteristics. Mutation breeding with a high standard variety maybe more promising than a long-term cross-breeding program and should, in the opinion of the author, also be attempted in other countries. Through the co-operation of the authorities of the Serdang Agriculture College, the use of their paddy fields for observation and experimentation has been secured. Preliminary work to assess the type of borer and infestation in the most common rice-varieties namely Mahsuri, Malinja and Ria is already in progress. This is essential because most of the previous work on stem borers in Malaya has been carried out on older varieties which are not much favoured either by the government or by the people. All the four species mentioned earlier have been found attacking the new varieties at Serdang. At present, the data are too meagre to warrant any definite conclusions, but the following possibilities are indicated by the field observation. (a) Some species of borers are more common in one locality than other species, (b) In a particular locality there seems to be a quantitative host variety preference, (c) There is no indication of a relationship between the borer infestation and the habit of the plants, (d) Some varieties are possibly more vulnerable during younger stages. (e

Electrical properties of Lupinus angustifolius L. stem. II. Accommodation and anode break excitation

Directory of Open Access Journals (Sweden)

Tadeusz Zawadzki

2015-01-01

Full Text Available Under electrical stimulation of Lupinus stem phenomena of accommodation and anode break excitation appear. Their characteristic is the same as in the axon or nerve. Only their duration is about 103-104 longer in plants. The constant characterizing the rate of accommodation was calculated. A limiting threshold value was found beyond which excitation occurs, irrespective of the rate of stimulus rise (voltage gradient. The accommodation rate is approximately constant, whereas the range of accommodation varies and is dependent on the difference between the rheobase value and the limiting threshold value. Hence plants with a low rheobase are characterized by a wider range of accommodation. It is suggested that the changes in potential (including AP recorded on the stem surface are connected with changes of the potential on cell membranes (Sibaoka, 1962.

Correlated evolution of stem and leaf hydraulic traits in Pereskia (Cactaceae).

Science.gov (United States)

Edwards, Erika J

2006-01-01

Recent studies have demonstrated significant correlations between stem and leaf hydraulic properties when comparing across species within ecological communities. This implies that these traits are co-evolving, but there have been few studies addressing plant water relations within an explicitly evolutionary framework. This study tests for correlated evolution among a suite of plant water-use traits and environmental parameters in seven species of Pereskia (Cactaceae), using phylogenetically independent contrasts. There were significant evolutionary correlations between leaf-specific xylem hydraulic conductivity, Huber Value, leaf stomatal pore index, leaf venation density and leaf size, but none of these traits appeared to be correlated with environmental water availability; only two water relations traits - mid-day leaf water potentials and photosynthetic water use efficiency - correlated with estimates of moisture regime. In Pereskia, it appears that many stem and leaf hydraulic properties thought to be critical to whole-plant water use have not evolved in response to habitat shifts in water availability. This may be because of the extremely conservative stomatal behavior and particular rooting strategy demonstrated by all Pereskia species investigated. These results highlight the need for a lineage-based approach to understand the relative roles of functional traits in ecological adaptation.

Antimosquito Phenylpropenoids from the Stem and Root Barks of ...

African Journals Online (AJOL)

Michael Horsfall

The plant species was identified on site and its identity was further confirmed at the Herbarium of the. Department of Botany, University of Dar es Salaam, where a voucher specimen is deposited. Extraction and Isolation: The air dried and pulverized root and stem barks were extracted sequentially with CHCl3 and MeOH, 2 x ...

Stem Bark Extracts of Ficus exasperata protects the Liver against ...

African Journals Online (AJOL)

Ficus exasperata is an important medicinal plant with a wide geographical distribution in Africa particularly in Nigeria. In this study, aqueous stem bark extracts of Ficus exasperata were administered to investigate its hepatoprotective effects on Paracetamol induced liver toxicity in Wistar rats. A total of Twenty Five Wistar rats ...

Effects of the ethanolic stem bark extract of pterocarpus erinaceus ...

African Journals Online (AJOL)

This finding might lend credence to the use of the stem bark of the plant in the treatment of diarrhea and dysentery traditionally. From the results of this work and information from literature, flavonoids and tannins identified during phytochemical screening of the extract may be the biologically active components responsible ...

Effect of seed treatment using low doses of X-rays in peppers plants (Capsicum annuum L.)

International Nuclear Information System (INIS)

Alvarez Fonseca, Alexander; Chavez Suarez, Licet; Ramirez Fernandez, Ramiro

2013-01-01

The influence of seed treatment with X-rays radiation on the growth and yield of peppers plants of the California Wonder variety was studied. The seeds were irradiated with X- rays irradiation source of low potency (11.47 Gy/min), with doses of 5, 10, 20 y 30 Gy, using untreated seeds as controls. Plant height (mm), root length (mm), stem diameter (mm), polar average diameter (mm) ecuatorial mean diameter (mm), mean fruit mass (g) and yield per plant (kg.plant''1 ) were evaluated. The results showed a significant improvement (p≤ 0.001) in the indicators of plants height (15%), root length (12%), stem diameter (7%), equatorial mean diameter (47%), mean fruit mass (16%) and yield per plant (107%), compared to control

Alert Systems for production Plants

DEFF Research Database (Denmark)

Nielsen, Thomas Dyhre; Jensen, Finn Verner

2005-01-01

We present a new methodology for detecting faults and abnormal behavior in production plants. The methodology stems from a joint project with a Danish energy consortium. During the course of the project we encountered several problems that we believe are common for projects of this type. Most...

Recognition of plant parts with problem-specific algorithms

Science.gov (United States)

Schwanke, Joerg; Brendel, Thorsten; Jensch, Peter F.; Megnet, Roland

1994-06-01

Automatic micropropagation is necessary to produce cost-effective high amounts of biomass. Juvenile plants are dissected in clean- room environment on particular points on the stem or the leaves. A vision-system detects possible cutting points and controls a specialized robot. This contribution is directed to the pattern- recognition algorithms to detect structural parts of the plant.

Pharmacobotanic characterization of young stems and stem barks of Rauvolfia sellowii Müll. Arg., Apocynaceae

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Leopoldo Clemente Baratto

2010-09-01

Full Text Available Rauvolfia sellowii Müll. Arg. (Apocynaceae, a Brazilian native tree rich in indole alkaloids, is known as "pau-pra-tudo" and popularly used as hypocholesterolemic, hypoglycemic and antihypertensive. The aim of this work was to study the anatomy of the young stems and stem barks of this medicinal plant, in order to contribute to the identification of the species as a drug. The plant material was fixed and prepared according to standard microtechniques. The young stems have remaining epidermis, but a suberified peridermis is evident. The phellogen is located in the cortical region, forming suber externally. Underneath the phellogen, lies the phelloderm and collenchymatic region. In the cortex, there are numerous laticifers and some fibers. There is an incomplete sclerenchymatic sheath, consisting of several groups of fibers and stone cells. The stem has internal phloem ordered as isolated groups side by side. Numerous laticifers, calcium oxalate crystals, idioblasts and amyloplasts are found in the cortex, phloem, xylem and pith. The stem bark has many layers of suber and cortical parenchyma, a sheath composed of fibers and stone cells totally lignified, and external phloem. These anatomical characteristic, taken together, can be used as quality control parameters for this species.Rauvolfia sellowii Müll. Arg. (Apocynaceae, uma árvore nativa brasileira rica em alcaloides indólicos, é conhecida como "pau-pra-tudo" e utilizada popularmente como hipocolesterolêmica, hipoglicêmica e anti-hipertensiva. O presente trabalho teve como objetivo caracterizar anatomicamente o caule jovem e a casca caulinar dessa planta medicinal, a fim de contribuir para a identificação e autenticidade da droga. O material vegetal foi fixado e submetido às microtécnicas usuais. O caule jovem possui epiderme remanescente, porém uma periderme suberificada é observada. O felogênio instala-se na região cortical, formando súber externamente. Subjacentes ao felog

Heavy metals in the soils and plants from a typical restored coal-mining area of Huainan coalfield, China.

Science.gov (United States)

Niu, Siping; Gao, Liangmin; Zhao, Junjie

2017-09-03

This study was conducted to pursue the heavy metals in the soil and plants of a typical restored coal-mining area, China. The average concentrations of Cu, Zn, Cr, Ni, and Pb in soil were 26.4, 76.1, 188.6, 34.3, and 50.2 mg kg -1 , respectively, implying a significant accumulation of Cr, Ni, and Pb compared with the background values. Contamination factor indicates that the soil underwent none to medium pollution by Cu and Zn, medium to strong by Cr, none to strong by Pb, and medium pollution by Ni while the pollution load index means that the soil was subjected to intermediate contamination. Based on the critical threshold values to protect the plants, the investigated metals were unable to affect the plants. One-way ANOVA analysis shows that Cu, Zn, and Pb in plants varied with plant tissues. Cu-Cr, Cu-Ni, Zn-Ni, Zn-Pb, Cr-Ni, and Ni-Pb pairs had significant positive correlation both in soil and in plants due to the similar soil characteristics and plant physiologies. Correspondence analysis indicates that Pb was more likely to be accumulative in stems and leaves. In addition, the levels of Cu and Cr in plant followed an order of roots > stems > leaves; Zn and Ni leaves ≥ stems > roots; and Pb followed stems ≥ leaves > roots. Generally, this study suggests that the plants like Ligustrum lucidum Aiton and Weigela hortensis, which are capable of accumulating Cr, Ni, and Pb, should be the predominant species in the studied area.

Modulation of differentiation and self-renewal of tissue specific stem cells for effective mitigation of radiation injury

International Nuclear Information System (INIS)

Bandekar, Mayuri; Patwardhan, R.S.; Maurya, Dharmendra K.; Bhilwade, Hari N.; Sharma, Deepak; Sandur, Santosh Kumar

2017-01-01

The use of stem cells in regenerative medicine for the treatment of various human diseases is one of the active research areas. The aim of regenerative medicine is to restore normal tissue functions by replenishing injured tissues using either cell-based therapy or by inducing certain factors that can aid endogenous repair and regeneration. The approach for inducing endogenous repair and regeneration requires in vivo modulation of tissue-specific stem cells by therapeutic agents and enhance their abundance through activation, proliferation, differentiation, or reprogramming. Here we describe three different approaches to enhance the abundance of hematopoietic stem cells in vivo for mitigation of radiation induced toxicity. Baicalein, a flavonoid derived from Chinese and Indian medicinal plants like Scutellaria baicalensis and Terminalia ariuna enhanced the abundance of hematopoietic stem cells through activation of Nrf-2 in the lineage negative cells. Another anti-oxidant, chlorophyllin derived from green plant pigment, chlorophyll also enhanced the abundance of hematopoietic stem cells through modulation of cell cycle in cells of the bone marrow. Treatment of mice with Cobaltus chloride (CoCl_2), a well-known activator of hypoxia inducible factor-1α (HIP-1α), also led to increase in the number of hematopoietic stem cells in the bone marrow. Whereas chlorophyllin offered up to 100 % protection against whole body irradiation (WBI, 8 Gy) induced mortality in mice, baicalein offered up to70%protection. Cobaltus chloride treatment offered 40% protection against 8 Gy of WBI. These studies indicate potential use of stem cell modulating agents as effective mitigators of radiation induced toxicity in vivo. (author)

Comparison of total phenolic content, scavenging activity and HPLC-ESI-MS/MS profiles of both young and mature leaves and stems of Andrographis paniculata.

Science.gov (United States)

Chua, Lee Suan; Yap, Ken Choy; Jaganath, Indu Bala

2013-12-01

The total phenolic content and radical scavenging activity of Andrographis paniculata has been investigated to estimate the amount of phenolic compounds and diterpene lactones, respectively in the plant extracts. The stem extracts exhibited higher total phenolic content and scavenging activity than those of the leaf extracts from both young and mature plants. A range of 19.6-47.8 mg extract of A. paniculata from different parts of the plant is equivalent to the scavenging activity exhibited by one mg of standard Trolox. HPLC-ESI-MS/MS was also used to identify simultaneously the phytochemicals from the leaves and stems of both young and mature plant samples. Of the identified compounds, seven of the sixteen diterpene lactones, three of the six flavonoids, five of the six phenolic acids and two cyclic acids are reported here for the first time for this species. Multivariate statistical approaches such as Hierarchiral Component Analysis (HCA) and Principle Component Analysis (PCA) have clustered the plant extracts into the leaf and stem groups, regardless of plant age. Further classification based on the phytochemical profiles revealed that mostly phenolic acids and flavonoids were from the young leaf extracts, and diterpenoids and their glycosides from the mature leaf extracts. However, the phytochemical profiles for the stems of both young and mature plants were not significantly different as presented in the dendrogram of HCA and the score plot of PCA. The marker for mature plants might be the m/z 557 ion (dihydroxyl dimethyl 19-[(beta-D-glucopyranosyl)oxy]-19-oxo-ent-labda-8(17),13-dien-16,15-olide), whereas the m/z 521 ion (propyl neoandrographolide) could be the marker for leaf extracts.

Variations and determinants of carbon content in plants: a global synthesis

Science.gov (United States)

Ma, Suhui; He, Feng; Tian, Di; Zou, Dongting; Yan, Zhengbing; Yang, Yulong; Zhou, Tiancheng; Huang, Kaiyue; Shen, Haihua; Fang, Jingyun

2018-02-01

Plant carbon (C) content is one of the most important plant traits and is critical to the assessment of global C cycle and ecological stoichiometry; however, the global variations in plant C content remain poorly understood. In this study, we conducted a global analysis of the plant C content by synthesizing data from 4318 species to document specific values and their variation of the C content across plant organs and life forms. Plant organ C contents ranged from 45.0 % in reproductive organs to 47.9 % in stems at global scales, which were significantly lower than the widely employed canonical value of 50 %. Plant C content in leaves (global mean of 46.9 %) was higher than that in roots (45.6 %). Across life forms, woody plants exhibited higher C content than herbaceous plants. Conifers, relative to broad-leaved woody species, had higher C content in roots, leaves, and stems. Plant C content tended to show a decrease with increasing latitude. The life form explained more variation of the C content than climate. Our findings suggest that specific C content values of different organs and life forms developed in our study should be incorporated into the estimations of regional and global vegetation biomass C stocks.

Variations and determinants of carbon content in plants: a global synthesis

Directory of Open Access Journals (Sweden)

S. Ma

2018-02-01

Full Text Available Plant carbon (C content is one of the most important plant traits and is critical to the assessment of global C cycle and ecological stoichiometry; however, the global variations in plant C content remain poorly understood. In this study, we conducted a global analysis of the plant C content by synthesizing data from 4318 species to document specific values and their variation of the C content across plant organs and life forms. Plant organ C contents ranged from 45.0 % in reproductive organs to 47.9 % in stems at global scales, which were significantly lower than the widely employed canonical value of 50 %. Plant C content in leaves (global mean of 46.9 % was higher than that in roots (45.6 %. Across life forms, woody plants exhibited higher C content than herbaceous plants. Conifers, relative to broad-leaved woody species, had higher C content in roots, leaves, and stems. Plant C content tended to show a decrease with increasing latitude. The life form explained more variation of the C content than climate. Our findings suggest that specific C content values of different organs and life forms developed in our study should be incorporated into the estimations of regional and global vegetation biomass C stocks.

Effects of IAA, IBA, NAA, and GA3 on rooting and morphological features of Melissa officinalis L. stem cuttings.

Science.gov (United States)

Sevik, Hakan; Guney, Kerim

2013-01-01

This study analyzed the potential of producing Melissa officinalis L. using stem cuttings. Four different hormones (IAA, IBA, NAA, and GA3) were applied to the cuttings, with and without buds, in two doses (1000 mg/L and 5000 mg/L), and after 60 days, 10 morphological characteristics of newly generated plants were detected, and a statistical analysis was carried out. The results of the study show that the cuttings with at least one bud must be used in order to produce M. officinalis using stem cuttings. Even though the auxin group hormones (IAA, IBA, and NAA) do not have an apparent effect on rooting percentage, these hormones were detected to affect the morphological characteristics of the newly generated plants, especially root generation. GA3 application has a considerable effect on stem height.

The nutritional value of sorghum bicolor stem flour used for infusion drinks in nigeria

International Nuclear Information System (INIS)

Adetuyi, A.O.; Akpambang, V.O.E.

2006-01-01

The black purple sheath (stem) of Sorgum bicolor, used locally as colour additive in cooked meals and infusion drinks taken as beverages, was examined for its nutritive value. The stem made into flour, was found to be rich in energy (1121.3 kJ/100 g), and in some micronutrients (mg/100 g), such as Mg (185.33), Ca (151.70), K (138.87), Na (127.61), and Fe (10.98). High Mg content of stem may be useful for overcoming Mg deficiency. The Fe content was sufficient to meet the daily-required intake (DRI) value for human beings. The presence of Cu, Zn and Mn was also observed. The content of crude fibre (32.0%) and carbohydrates (44.50%) were useful for making the stem a fodder for animal consumption. However, the protein content of the stem was low (3.20%). The functional properties observed for the stem compared favourably with those already reported for some other plants such as pigeon pea flour, African yam bean, and wheat flour. (author)

Anti-HIV-1 integrase activity of medicinal plants used as self medication by AIDS patients

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Sopa Kummee

2006-07-01

Full Text Available The extracts of selected medicinal plants used as self medication by AIDS patients were investigated for their inhibitory activities against HIV-1 integrase (HIV-1 IN using the multiplate integration assay (MIA. Of these, the water extract of Eclipta prostrata (whole plant exhibited the most potent inhibitory activity with an IC50 value of 4.8 μg/ml, followed by the methanol extract of Eclipta prostrata (whole plant, IC50 = 21.1 μg/ ml, the water extract of Barleria lupulina (stem, IC50 = 26.4 μg/ml, the chloroform extract of Barleria lupulina (stem, IC50 = 33.0 μg/ml, the methanol extract of Barleria lupulina (stem, IC50 = 38.2 μg/ml and the chloroform extract of Piper betle (leaf, IC50 = 39.3 μg/ml, respectively.

Lr67/Yr46 confers adult plant resistance to stem rust and powdery mildew in wheat.

Science.gov (United States)

Herrera-Foessel, Sybil A; Singh, Ravi P; Lillemo, Morten; Huerta-Espino, Julio; Bhavani, Sridhar; Singh, Sukhwinder; Lan, Caixia; Calvo-Salazar, Violeta; Lagudah, Evans S

2014-04-01

We demonstrate that Lr67/Yr46 has pleiotropic effect on stem rust and powdery mildew resistance and is associated with leaf tip necrosis. Genes are designated as Sr55, Pm46 and Ltn3 , respectively. Wheat (Triticum aestivum) accession RL6077, known to carry the pleiotropic slow rusting leaf and yellow rust resistance genes Lr67/Yr46 in Thatcher background, displayed significantly lower stem rust (P. graminis tritici; Pgt) and powdery mildew (Blumeria graminis tritici; Bgt) severities in Kenya and in Norway, respectively, compared to its recurrent parent Thatcher. We investigated the resistance of RL6077 to stem rust and powdery mildew using Avocet × RL6077 F6 recombinant inbred lines (RILs) derived from two photoperiod-insensitive F3 families segregating for Lr67/Yr46. Greenhouse seedling tests were conducted with Mexican Pgt race RTR. Field evaluations were conducted under artificially initiated stem rust epidemics with Pgt races RTR and TTKST (Ug99 + Sr24) at Ciudad Obregon (Mexico) and Njoro (Kenya) during 2010-2011; and under natural powdery mildew epiphytotic in Norway at Ås and Hamar during 2011 and 2012. In Mexico, a mean reduction of 41 % on stem rust severity was obtained for RILs carrying Lr67/Yr46, compared to RILs that lacked the gene, whereas in Kenya the difference was smaller (16 %) but significant. In Norway, leaf tip necrosis was associated with Lr67/Yr46 and RILs carrying Lr67/Yr46 showed a 20 % reduction in mean powdery mildew severity at both sites across the 2 years of evaluation. Our study demonstrates that Lr67/Yr46 confers partial resistance to stem rust and powdery mildew and is associated with leaf tip necrosis. The corresponding pleiotropic, or tightly linked, genes, designated as Sr55, Pm46, and Ltn3, can be utilized to provide broad-spectrum durable disease resistance in wheat.

Types of Stem Cells

Science.gov (United States)

... Stem Cell Glossary Search Toggle Nav Types of Stem Cells Stem cells are the foundation from which all ... Learn About Stem Cells > Types of Stem Cells Stem cells Stem cells are the foundation for every organ ...

Controlling plant architecture by manipulation of gibberellic acid signalling in petunia

Science.gov (United States)

Gibberellic acid (GA), a plant hormone, regulates many crucial growth and developmental processes, including seed germination, leaf expansion, induction of flowering and stem elongation. A common problem in the production of ornamental potted plants is undesirably tall growth, so inhibitors of gibbe...

Antimicrobial Activity of Extracts from Leaves, Stems and Flowers of Euphorbia macroclada against plant pathogenic fungi

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K. Al-Mughrabi

2003-12-01

Full Text Available Extracts drawn from dried and powdered flowers, stems and leaves of Euphorbia macroclada with some organic solvents were tested for antimicrobial effect against the fungi Verticillium dahliae, Fusarium oxysporum, Rhizopus stolonifer, Penicillium italicum, Rhizoctonia solani, Alternaria solani, Stemphylium solani, Cladosporium sp., Mucor sp., and Pythium sp. The strongest inhibitory effect of the extracts was observed against R. solani, V. dahliae, F. oxysporum, Pythium sp. and R. stolonifer. The weakest effect was against A. solani. Extracts from the stems had a stronger inhibitory effect than those from the flowers or leaves. Butanol was the best solvent to extract antimicrobial compounds from leaves, stems and flowers and was superior to chloroform, water and petroleum ether. Results clearly indicate that E. macroclada is a promising source of antimicrobial compounds.

Statistical Analysis Of Heavy Metals Concentration In Watermelon Plants Irrigated By Wastewater

Science.gov (United States)

Khanjani, M. J.; Maghsoudi moud, A. A.; Saffari, V. R.; Hashamipor, S. M.; Soltanizadeh, M.

2008-01-01

Concentration of heavy metals in vegetables irrigated by urban wastewater is a cause of serious concern due to the potentials health problems of consuming contaminated produce. In this study it is tried to model the concentration of heavy metals (Cd, Cr, Cu, Fe,…) as a function of their concentration in watermelon roots and stems. Our study shows there is a good relationship between them for most of collected data. By measuring the concentration in root and stem of watermelon plant samples before harvesting, the concentration of heavy metal in watermelon's fruit can be estimated by presented mathematical models. This study shows the concentrations of heavy metals in fruits, roots and stems of watermelon plants are very high and in dangerous level when irrigated by municipal waste water.

In Vitro Morphogenesis of Arabidopsis to Search for Novel Endophytic Fungi Modulating Plant Growth.

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Francesco Dovana

Full Text Available Fungal endophytes have shown to affect plant growth and to confer stress tolerance to the host; however, effects of endophytes isolated from water plants have been poorly investigated. In this study, fungi isolated from stems (stem-E and roots (root-E of Mentha aquatica L. (water mint were identified, and their morphogenetic properties analysed on in vitro cultured Arabidopsis (L. Heynh., 14 and 21 days after inoculation (DAI. Nineteen fungi were analysed and, based on ITS analysis, 17 isolates showed to be genetically distinct. The overall effect of water mint endophytes on Arabidopsis fresh (FW and dry weight (DW was neutral and positive, respectively, and the increased DW, mainly occurring 14 DAI, was possibly related to plant defence mechanism. Only three fungi increased both FW and DW of Arabidopsis at 14 and 21 DAI, thus behaving as plant growth promoting (PGP fungi. E-treatment caused a reduction of root depth and primary root length in most cases and inhibition-to-promotion of root area and lateral root length, from 14 DAI. Only Phoma macrostoma, among the water mint PGP fungi, increased both root area and depth, 21 DAI. Root depth and area 14 DAI were shown to influence DWs, indicating that the extension of the root system, and thus nutrient uptake, was an important determinant of plant dry biomass. Reduction of Arabidopsis root depth occurred to a great extent when plants where treated with stem-E while root area decreased or increased under the effects of stem-E and root-E, respectively, pointing to an influence of the endophyte origin on root extension. M. aquatica and many other perennial hydrophytes have growing worldwide application in water pollution remediation. The present study provided a model for directed screening of endophytes able to modulate plant growth in the perspective of future field applications of these fungi.

In Vitro Morphogenesis of Arabidopsis to Search for Novel Endophytic Fungi Modulating Plant Growth.

Science.gov (United States)

Dovana, Francesco; Mucciarelli, Marco; Mascarello, Maurizio; Fusconi, Anna

2015-01-01

Fungal endophytes have shown to affect plant growth and to confer stress tolerance to the host; however, effects of endophytes isolated from water plants have been poorly investigated. In this study, fungi isolated from stems (stem-E) and roots (root-E) of Mentha aquatica L. (water mint) were identified, and their morphogenetic properties analysed on in vitro cultured Arabidopsis (L.) Heynh., 14 and 21 days after inoculation (DAI). Nineteen fungi were analysed and, based on ITS analysis, 17 isolates showed to be genetically distinct. The overall effect of water mint endophytes on Arabidopsis fresh (FW) and dry weight (DW) was neutral and positive, respectively, and the increased DW, mainly occurring 14 DAI, was possibly related to plant defence mechanism. Only three fungi increased both FW and DW of Arabidopsis at 14 and 21 DAI, thus behaving as plant growth promoting (PGP) fungi. E-treatment caused a reduction of root depth and primary root length in most cases and inhibition-to-promotion of root area and lateral root length, from 14 DAI. Only Phoma macrostoma, among the water mint PGP fungi, increased both root area and depth, 21 DAI. Root depth and area 14 DAI were shown to influence DWs, indicating that the extension of the root system, and thus nutrient uptake, was an important determinant of plant dry biomass. Reduction of Arabidopsis root depth occurred to a great extent when plants where treated with stem-E while root area decreased or increased under the effects of stem-E and root-E, respectively, pointing to an influence of the endophyte origin on root extension. M. aquatica and many other perennial hydrophytes have growing worldwide application in water pollution remediation. The present study provided a model for directed screening of endophytes able to modulate plant growth in the perspective of future field applications of these fungi.

Different waves of effector genes with contrasted genomic location are expressed by Leptosphaeria maculans during cotyledon and stem colonization of oilseed rape.

Science.gov (United States)

Gervais, Julie; Plissonneau, Clémence; Linglin, Juliette; Meyer, Michel; Labadie, Karine; Cruaud, Corinne; Fudal, Isabelle; Rouxel, Thierry; Balesdent, Marie-Hélène

2017-10-01

Leptosphaeria maculans, the causal agent of stem canker disease, colonizes oilseed rape (Brassica napus) in two stages: a short and early colonization stage corresponding to cotyledon or leaf colonization, and a late colonization stage during which the fungus colonizes systemically and symptomlessly the plant during several months before stem canker appears. To date, the determinants of the late colonization stage are poorly understood; L. maculans may either successfully escape plant defences, leading to stem canker development, or the plant may develop an 'adult-stage' resistance reducing canker incidence. To obtain an insight into these determinants, we performed an RNA-sequencing (RNA-seq) pilot project comparing fungal gene expression in infected cotyledons and in symptomless or necrotic stems. Despite the low fraction of fungal material in infected stems, sufficient fungal transcripts were detected and a large number of fungal genes were expressed, thus validating the feasibility of the approach. Our analysis showed that all avirulence genes previously identified are under-expressed during stem colonization compared with cotyledon colonization. A validation RNA-seq experiment was then performed to investigate the expression of candidate effector genes during systemic colonization. Three hundred and seven 'late' effector candidates, under-expressed in the early colonization stage and over-expressed in the infected stems, were identified. Finally, our analysis revealed a link between the regulation of expression of effectors and their genomic location: the 'late' effector candidates, putatively involved in systemic colonization, are located in gene-rich genomic regions, whereas the 'early' effector genes, over-expressed in the early colonization stage, are located in gene-poor regions of the genome. © 2016 BSPP AND JOHN WILEY & SONS LTD.

Stems age, nitrogen fertilizer and salicylic acid application in cutting induction of noble dendrobium orchid of the Yamamoto series cultivars

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Jeferson João Soccol

2017-06-01

Full Text Available Propagation of noble dendrobium orchid (Dendrobium nobile Lindl. by cutting was studied in two experiments. In the first experiment we evaluated the effect stem age on propagation success: mature stems - from already bloomed stems; and young stems – yet to bloom; and Nitrogen fertilizer application, from two sources: as Nitrate and Ammonium (respectively as Calcium Nitrate at concentrations of: 5.81 gL-1; 11.61 gL-1; 17.42 gL-1; and Urea at concentrations of 2.00 gL-1; 4.00 gL-1 and 6.00 gL-1 plus control treatments. We evaluated the following parameters: the number of cuttings stalks that launched shoots and/or roots, vigor, number of roots per plant and root length per plant. Factorial analysis of variance (stems age x source of Nitrogen; and age of stem x Nitrogen level was applied using a Generalized Linear Model (GLM approach. Where significant differences were observed, averages were compared using post-hoc tests (Tukey. Propagation success was higher using cuttings from mature stems (60.2%, a value 1.6 times higher than obtained with stem cuttings from young stems (38.0%. Application of Nitrogen, in both forms, did not influence any of the evaluated parameters. In the second experiment we treated cuttings from mature stems with Salicylic acid in 3 concentrations (0.10 mM; 0.50 mM; 1.00 mM and plus a control treatment. Evaluated parameters included proportion of cuttings stalks that launched shoots and/or roots, leaf length, root length, and number of roots per stem cutting. Factorial analysis of variance was applied with post-hoc tests. Application of 0.50 mM of Salicylic acid increased the proportion of cuttings stalks that launched shoots and/or roots by 20.5% relative to the control treatment.

An improved method of DNA extraction from plants for pathogen ...

African Journals Online (AJOL)

Polymerase chain reaction (PCR)-based applications in plant molecular biology and molecular diagnostics for plant pathogens require good quality DNA for reliable and reproducible results. Leaf tissue is often the choice for DNA extraction, but the use of other sources such as tubers, stems, or seeds, is not uncommon.

Antinociceptive effect of the ethanol extract of the stem bark of ...

African Journals Online (AJOL)

Musanga cecropioides R. Apud Tedlie (Cecropiaceae), also known as umbrella tree is one of the medicinal plants used in Nigeria for pain and inflammation. The stem bark was extracted with absolute ethanol and screened for analgesic activities. The screening for analgesic properties was done using: acetic acid induced ...

Growth and development of tomato plants Lycopersicon Esculentum Mill. under different saline conditions by fertirrigation with pretreated cheese whey wastewater.

Science.gov (United States)

Prazeres, Ana R; Carvalho, Fátima; Rivas, Javier; Patanita, Manuel; Dôres, Jóse

2013-01-01

Pretreated cheese whey wastewater (CWW) has been used at different salinity levels: 1.75, 2.22, 3.22, 5.02 and 10.02 dS m(-1) and compared with fresh water (1.44 dS m(-1)). Two cultivars (cv.) of the tomato plant Lycopersicon Esculentum Mill. (Roma and Rio Grande) were exposed to saline conditions for 72 days. Salinity level (treatment) had no significant effects on the fresh weight and dry matter of the leaves, stems and roots. Similar results were found when specific leaf area, leaflet area, ramifications number of 1st order/plant, stem diameter and length, nodes number/stem and primary root length were considered. Conversely, the salinity level significantly influenced the Soil Plant Analysis Development (SPAD) index and the distance between nodes in the plant stem. In the first case, an increase of 21% was obtained in the salinity levels of 5.02 and 10.02 dS m(-1) for cv. Rio Grande, compared with the control run. The results showed that the pretreated CWW can be a source of nutrients for tomato plants, with reduced effects on growth and development.

Plant uptake and transport of 241Am

International Nuclear Information System (INIS)

Wallace, A.; Romney, E.M.; Mueller, R.T. Sr.; soufi, S.M.

1981-01-01

We conducted several experiments with 241 Am to obtain a more complete understanding of how this transuranium element is absorbed and transported in plants. In a plant species (Tamarix pentandra Pall.) that has salt glands in the leaves excreting NaCl and other ions, 241 Am was not pumped through these glands. Cyanide, which forms complexes with any metals, when applied to a calcareous soil, greatly increased the transport of 241 Am into stems and leaves of bush bean plants. Radioactive cyanide ( 14 C) was also transported to leaves and stems. When radish was grown in both calcareous and noncalcareous soils, 241 Am appeared to be fixed on the peel so firmly that it was resistant to removal by HNO 3 washing. The chelating agent DTPA induced increased transport of 241 Am to leaves and into the fleshy roots of the radish. Data for Golden Cross hybrid corn grown in solution culture showed at least seven times as much 241 Am transport to the xylem exudatields are corrected by recovery of added tracers

Comparative analgesic activity of the root bark, stem bark, leaves ...

African Journals Online (AJOL)

The analgesic activity of the water extracts (50,100 and150 mg/Kg body weight) of the root bark, stem bark, leaves, fruits and seeds of Carissa edulis were evaluated in mice using the mechanical method (tail-chip method) and chemical method (acetic acid induced writhing). The plant was found to have analgesic activity, ...

Visual object recognition for automatic micropropagation of plants

Science.gov (United States)

Brendel, Thorsten; Schwanke, Joerg; Jensch, Peter F.

1994-11-01

Micropropagation of plants is done by cutting juvenile plants and placing them into special container-boxes with nutrient-solution where the pieces can grow up and be cut again several times. To produce high amounts of biomass it is necessary to do plant micropropagation by a robotic system. In this paper we describe parts of the vision system that recognizes plants and their particular cutting points. Therefore, it is necessary to extract elements of the plants and relations between these elements (for example root, stem, leaf). Different species vary in their morphological appearance, variation is also immanent in plants of the same species. Therefore, we introduce several morphological classes of plants from that we expect same recognition methods.

STEM Education.

Science.gov (United States)

Xie, Yu; Fang, Michael; Shauman, Kimberlee

2015-08-01

Improving science, technology, engineering, and mathematics (STEM) education, especially for traditionally disadvantaged groups, is widely recognized as pivotal to the U.S.'s long-term economic growth and security. In this article, we review and discuss current research on STEM education in the U.S., drawing on recent research in sociology and related fields. The reviewed literature shows that different social factors affect the two major components of STEM education attainment: (1) attainment of education in general, and (2) attainment of STEM education relative to non-STEM education conditional on educational attainment. Cognitive and social psychological characteristics matter for both major components, as do structural influences at the neighborhood, school, and broader cultural levels. However, while commonly used measures of socioeconomic status (SES) predict the attainment of general education, social psychological factors are more important influences on participation and achievement in STEM versus non-STEM education. Domestically, disparities by family SES, race, and gender persist in STEM education. Internationally, American students lag behind those in some countries with less economic resources. Explanations for group disparities within the U.S. and the mediocre international ranking of US student performance require more research, a task that is best accomplished through interdisciplinary approaches.

A WUSCHEL-Independent Stem Cell Specification Pathway Is Repressed by PHB, PHV and CNA in Arabidopsis

Science.gov (United States)

Lee, Chunghee; Clark, Steven E.

2015-01-01

The homeostatic maintenance of stem cells that carry out continuous organogenesis at the shoot meristem is crucial for plant development. Key known factors act to signal between the stem cells and an underlying group of cells thought to act as the stem cell niche. In Arabidopsis thaliana the homeodomain transcription factor WUSCHEL (WUS) is essential for stem cell initiation and maintenance at shoot and flower meristems. Recent data suggest that the WUS protein may move from the niche cells directly into the stem cells to maintain stem cell identity. Here we provide evidence for a second, previously unknown, pathway for stem cell specification at shoot and flower meristems that bypasses the requirement for WUS. We demonstrate that this novel stem cell specification pathway is normally repressed by the activity of the HD-zip III transcription factors PHABULOSA (PHB), PHAVOLUTA (PHV) and CORONA (CNA). When de-repressed, this second stem cell pathway leads to an accumulation of stem cells and an enlargement of the stem cell niche. When de-repressed in a wus mutant background, this second stem cell pathway leads to functional meristems with largely normal cell layering and meristem morphology, activation of WUS cis regulatory elements, and extensive, but not indeterminate, organogenesis. Thus, WUS is largely dispensable for stem cell specification and meristem function, suggesting a set of key stem cell specification factors, competitively regulated by WUS and PHB/PHV/CNA, remain unidentified. PMID:26011610

Traits of estuarine marsh plants affect wave dissipation

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Schulte Ostermann, Tilla; Heuner, Maike; Bouma, Tjeerd

2017-04-01

Estuarine vegetation can attenuate hydrodynamic forces such as waves or flow velocities and therefore has an important role in natural tidal bank protection. This function depends on the degree of hydrodynamic forces, bank morphology and on plant traits of the dominant species. The traits vary between the species but also between different marsh sites. Biomass, stem density and biomechanical properties are crucial factors that influence the rate of wave dissipation. These properties illustrate the trade-offs a species is facing in such a dynamic habitat and highlight the ability of dominant species such as Bolboschoenus maritimus and Schoenoplectus tabernaemontani to protect the tidal bank. Along the Elbe estuary, traits of dominant marsh plant species were measured on different sites. The sites vary e.g. in their elevation, salt levels and inundation periods. To analyse the role that plant traits can play in wave dissipation, the structure of the vegetation as well as the composition was recorded. Biomechanical tests helped to understand the species traits regarding stem flexibility and to determine the effects of plant traits on wave dynamics and vice versa. On the conference, we will present how plant traits affect the wave dissipation on tidal marshes and why they vary.

Stem cell biobanks.

Science.gov (United States)

Bardelli, Silvana

2010-04-01

Stem cells contribute to innate healing and harbor a promising role for regenerative medicine. Stem cell banking through long-term storage of different stem cell platforms represents a fundamental source to preserve original features of stem cells for patient-specific clinical applications. Stem cell research and clinical translation constitute fundamental and indivisible modules catalyzed through biobanking activity, generating a return of investment.

Kinetics modeling of the drying of sunflower stem (Helianthus annuus L.) in a forced convection tunnel

International Nuclear Information System (INIS)

López, R; Vaca, M; Terres, H; Lizardi, A; Morales, J; Flores, J; Chávez, S

2015-01-01

The sunflower is an annual plant native to the Americas. It possesses a large inflorescence (flowering head), and its name is derived from the flower's shape and image, which is often used to capture the sun. The plant has a rough, broad, hairy stem, coarsely toothed, with rough leaves, and circular flower heads. The sunflower seeds are appreciated for their oil, which has become a widespread cooking ingredient. Leaves of the sunflower can be used as cattle feed, while the stems contain a fiber that may be used in paper production. Recently this flower has been used in phytoremediation of soils, contaminated with heavy metals. Sunflower has been probed as an efficient phytoextractor of chromium, lead, aluminum, zinc, cadmium from soil. In this work we present the experimental results of the drying of the sunflower stem, cut in 100 mm longitudinal sections, with diameters in the range of 11-18 mm. The aim was to obtain a dry and easy-to-handle final product, since these plants were originally cultivated in order to extract heavy metals from a polluted soil. The dried stems could then be easily confined or sent to recycle premises to concentrate the metals. The drying process was done in forced convection within a hot air tunnel. The used temperature was 60 °C, the velocity of air was 3 m/s and the required times were 8 hours. The initial average wet mass was 28 g and the final value was 5 g, resulting in the aimed product

Kinetics modeling of the drying of sunflower stem (Helianthus annuus L.) in a forced convection tunnel

Science.gov (United States)

López, R.; Vaca, M.; Terres, H.; Lizardi, A.; Morales, J.; Flores, J.; Chávez, S.

2015-01-01

The sunflower is an annual plant native to the Americas. It possesses a large inflorescence (flowering head), and its name is derived from the flower's shape and image, which is often used to capture the sun. The plant has a rough, broad, hairy stem, coarsely toothed, with rough leaves, and circular flower heads. The sunflower seeds are appreciated for their oil, which has become a widespread cooking ingredient. Leaves of the sunflower can be used as cattle feed, while the stems contain a fiber that may be used in paper production. Recently this flower has been used in phytoremediation of soils, contaminated with heavy metals. Sunflower has been probed as an efficient phytoextractor of chromium, lead, aluminum, zinc, cadmium from soil. In this work we present the experimental results of the drying of the sunflower stem, cut in 100 mm longitudinal sections, with diameters in the range of 11-18 mm. The aim was to obtain a dry and easy-to-handle final product, since these plants were originally cultivated in order to extract heavy metals from a polluted soil. The dried stems could then be easily confined or sent to recycle premises to concentrate the metals. The drying process was done in forced convection within a hot air tunnel. The used temperature was 60 °C, the velocity of air was 3 m/s and the required times were 8 hours. The initial average wet mass was 28 g and the final value was 5 g, resulting in the aimed product.

Stem Cell Basics

Science.gov (United States)

... Tips Info Center Research Topics Federal Policy Glossary Stem Cell Information General Information Clinical Trials Funding Information Current ... Basics » Stem Cell Basics I. Back to top Stem Cell Basics I. Introduction: What are stem cells, and ...

Studies on general resistance to stem rust in wheat

International Nuclear Information System (INIS)

Knott, D.R.

1977-01-01

Eight cultivars that were thought to have field resistance to stem rust were selected and crossed to produce four four-cultivar hybrids. From those crosses lines were produced that lacked seedling resistance to race 15B-1 of stem rust but had good field resistance to it. They also proved to have field resistance to many other races and it is hoped that the resistance is general. Genetic studies indicated that there is some variation in the lines, but resistance is generally inherited as a quantitative character with several largely recessive genes having small additive effects. This suggests that in an induced mutation programme, no one plant is likely to accumulate sufficient mutant genes that it will appear resistant. (author)

The target plant concept-a history and brief overview

Science.gov (United States)

Thomas D. Landis

2011-01-01

The target plant concept originated with morphological classification of conifer nursery stock in the 1930s, and the concept was enhanced through physiological research and seedling testing towards the end of the century. Morphological grading standards such as shoot height, stem diameter, and root mass are the most common use of the target plant concept, and some...

Long term effects of aqueous stem bark extract of Cissus populnea ...

African Journals Online (AJOL)

AJB SERVER

2007-02-05

Feb 5, 2007 ... Full Length Research Paper. Long term effects of aqueous stem bark extract of. Cissus populnea (Guill. and Per.) on some biochemical ... study period revealed that continuous exposure of the plant extract had no damaging effects on the organs of xenobiotic metabolism (liver and kidney). results of levels ...

Individual plant examination program aspirations and achievements

International Nuclear Information System (INIS)

Flack, J.H.

1994-01-01

An Individual Plant Examination (IPE) is a systematic examination of a nuclear power plant for vulnerabilities, or risk significant contributors. By mid 1994, all licensees of commercial nuclear power plants will have performed an IPE on their units. To date, the NRC staff has received sixty-three (80%) of the seventy-eight expected IPE submittals. Twelve IPE reviews are now complete, with twenty-two in various stages of review. This paper provides a preliminary overview and comparison of licensees IPEs to Commission objectives. Insights and findings stemming from the review program are also presented

An ABC transporter B family protein, ABCB19, is required for cytoplasmic streaming and gravitropism of the inflorescence stems.

Science.gov (United States)

Okamoto, Keishi; Ueda, Haruko; Shimada, Tomoo; Tamura, Kentaro; Koumoto, Yasuko; Tasaka, Masao; Morita, Miyo Terao; Hara-Nishimura, Ikuko

2016-01-01

A significant feature of plant cells is the extensive motility of organelles and the cytosol, which was originally defined as cytoplasmic streaming. We suggested previously that a three-way interaction between plant-specific motor proteins myosin XIs, actin filaments, and the endoplasmic reticulum (ER) was responsible for cytoplasmic streaming. (1) Currently, however, there are no reports of molecular components for cytoplasmic streaming other than the actin-myosin-cytoskeleton and ER-related proteins. In the present study, we found that elongated cells of inflorescence stems of Arabidopsis thaliana exhibit vigorous cytoplasmic streaming. Statistical analysis showed that the maximal velocity of plastid movements is 7.26 µm/s, which is much faster than the previously reported velocities of organelles. Surprisingly, the maximal velocity of streaming in the inflorescence stem cells was significantly reduced to 1.11 µm/s in an Arabidopsis mutant, abcb19-101, which lacks ATP BINDING CASSETTE SUBFAMILY B19 (ABCB19) that mediates the polar transport of the phytohormone auxin together with PIN-FORMED (PIN) proteins. Polar auxin transport establishes the auxin concentration gradient essential for plant development and tropisms. Deficiency of ABCB19 activity eventually caused enhanced gravitropic responses of the inflorescence stems and abnormally flexed inflorescence stems. These results suggest that ABCB19-mediated auxin transport plays a role not only in tropism regulation, but also in cytoplasmic streaming.

Biomass Allocation and Growth Data of Seeded Plants

Data.gov (United States)

National Aeronautics and Space Administration — ABSTRACT: This data set of leaf, stem, and root biomass for various plant taxa was compiled from the primary literature of the 20th century with a significant...

Influence of students' STEM self-efficacy on STEM and physics career choice

Science.gov (United States)

Halim, Lilia; Rahman, Norshariani Abd; Ramli, Nor Aidillina Mohd; Mohtar, Lilia Ellany

2018-01-01

Interest towards STEM and STEM careers is declining worldwide. Among the STEM related careers, the physics discipline has been the most affected in terms of numbers and imbalance of gender. This study investigates the role of self-efficacy in STEM towards STEM careers and Physics career based on gender and types of school. Findings showed that there is a positive and significant correlation between students' STEM self-efficacy and interest towards all disciplines in STEM and Physics career. Boys showed high level of self-efficacy in engineering discipline while the girls' associate more with science. Students from boarding schools showed higher self-efficacy and interest towards STEM careers compared to students from public schools. An implication of the study is that self-efficacy and interest in STEM careers are enhanced through engagement with STEM activities in and outside of school. Emphasis should be given to the role of counselors in making STEM careers relevant to students.

Modeling the leaf angle dynamics in rice plant.

Directory of Open Access Journals (Sweden)

Yonghui Zhang

Full Text Available The leaf angle between stem and sheath (SSA is an important rice morphological trait. The objective of this study was to develop and validate a dynamic SSA model under different nitrogen (N rates for selected rice cultivars. The time-course data of SSA were collected in three years, and a dynamic SSA model was developed for different main stem leaf ranks under different N rates for two selected rice cultivars. SSA increased with tiller age. The SSA of the same leaf rank increased with increase in N rate. The maximum SSA increased with leaf rank from the first to the third leaf, then decreased from the third to the final leaf. The relationship between the maximum SSA and leaf rank on main stem could be described with a linear piecewise function. The change of SSA with thermal time (TT was described by a logistic equation. A variety parameter (the maximum SSA of the 3rd leaf on main stem and a nitrogen factor were introduced to quantify the effect of cultivar and N rate on SSA. The model was validated against data collected from both pot and field experiments. The relative root mean square error (RRMSE was 11.56% and 14.05%, respectively. The resulting models could be used for virtual rice plant modeling and plant-type design.

Effects of plant growth regulators on callus, shoot and root formation ...

African Journals Online (AJOL)

Root and stem explants of fluted pumpkin were cultured in medium containing different types and concentrations of plant growth regulators (PGRs). The explants were observed for callus, root and shoot formation parameters after four months. Differences among explants, plant growth regulators and their interaction were ...

Aging, metabolism and stem cells: Spotlight on muscle stem cells.

Science.gov (United States)

García-Prat, Laura; Muñoz-Cánoves, Pura

2017-04-15

All tissues and organs undergo a progressive regenerative decline as they age. This decline has been mainly attributed to loss of stem cell number and/or function, and both stem cell-intrinsic changes and alterations in local niches and/or systemic environment over time are known to contribute to the stem cell aging phenotype. Advancing in the molecular understanding of the deterioration of stem cell cells with aging is key for targeting the specific causes of tissue regenerative dysfunction at advanced stages of life. Here, we revise exciting recent findings on why stem cells age and the consequences on tissue regeneration, with a special focus on regeneration of skeletal muscle. We also highlight newly identified common molecular pathways affecting diverse types of aging stem cells, such as altered proteostasis, metabolism, or senescence entry, and discuss the questions raised by these findings. Finally, we comment on emerging stem cell rejuvenation strategies, principally emanating from studies on muscle stem cells, which will surely burst tissue regeneration research for future benefit of the increasing human aging population. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Medicinal potential from in vivo and acclimatized plants of Cleome rosea.

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Simões, Claudia; De Mattos, José Carlos P; Sabino, Kátia C C; Caldeira-de-Araújo, Adriano; Coelho, Marsen G P; Albarello, Norma; Figueiredo, Solange F L

2006-02-01

Methanolic extracts obtained from different organs of Cleome rosea, collected from its natural habitat and from in vitro-propagated plants, were submitted to in vitro biological assays. Inhibition of nitric oxide (NO) production by J774 macrophages and antioxidant effects by protecting the plasmid DNA from the SnCl(2)-induced damage were evaluated. Extracts from the stem of both origins and leaf of natural plants inhibited NO production. The plasmid DNA strand breaks induced by SnCl(2) were reduced by extracts from either leaf or stem of both sources. On the other hand, root extracts did not show any kind of effects on plasmid DNA, and presented significant toxic effects to J774 cells. The results showed that C. rosea presents medicinal potential and that the acclimatization process reduces the plant toxicity both to plasmid DNA and to J774 cells, suggesting the use of biotechnology tools to obtain elite plants as source of botanical material for pharmacological and phytochemical studies.

AtMMS21, an SMC5/6 complex subunit, is involved in stem cell niche maintenance and DNA damage responses in Arabidopsis roots.

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Xu, Panglian; Yuan, Dongke; Liu, Ming; Li, Chunxin; Liu, Yiyang; Zhang, Shengchun; Yao, Nan; Yang, Chengwei

2013-04-01

Plants maintain stem cells in meristems to sustain lifelong growth; these stem cells must have effective DNA damage responses to prevent mutations that can propagate to large parts of the plant. However, the molecular links between stem cell functions and DNA damage responses remain largely unexplored. Here, we report that the small ubiquitin-related modifier E3 ligase AtMMS21 (for methyl methanesulfonate sensitivity gene21) acts to maintain the root stem cell niche by mediating DNA damage responses in Arabidopsis (Arabidopsis thaliana). Mutation of AtMMS21 causes defects in the root stem cell niche during embryogenesis and postembryonic stages. AtMMS21 is essential for the proper expression of stem cell niche-defining transcription factors. Moreover, mms21-1 mutants are hypersensitive to DNA-damaging agents, have a constitutively increased DNA damage response, and have more DNA double-strand breaks (DSBs) in the roots. Also, mms21-1 mutants exhibit spontaneous cell death within the root stem cell niche, and treatment with DSB-inducing agents increases this cell death, suggesting that AtMMS21 is required to prevent DSB-induced stem cell death. We further show that AtMMS21 functions as a subunit of the STRUCTURAL MAINTENANCE OF CHROMOSOMES5/6 complex, an evolutionarily conserved chromosomal ATPase required for DNA repair. These data reveal that AtMMS21 acts in DSB amelioration and stem cell niche maintenance during Arabidopsis root development.

Biomass Allocation and Growth Data of Seeded Plants

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National Aeronautics and Space Administration — This data set of leaf, stem, and root biomass for various plant taxa was compiled from the primary literature of the 20th century with a significant portion derived...

Non-Contact Plant Growth Measurement Method and System Based on Ubiquitous Sensor Network Technologies

Directory of Open Access Journals (Sweden)

Intae Ryoo

2011-04-01

Full Text Available This paper proposes a non-contact plant growth measurement system using infrared sensors based on the ubiquitous sensor network (USN technology. The proposed system measures plant growth parameters such as the stem radius of plants using real-time non-contact methods, and generates diameter, cross-sectional area and thickening form of plant stems using this measured data. Non-contact sensors have been used not to cause any damage to plants during measurement of the growth parameters. Once the growth parameters are measured, they are transmitted to a remote server using the sensor network technology and analyzed in the application program server. The analyzed data are then provided for administrators and a group of interested users. The proposed plant growth measurement system has been designed and implemented using fixed-type and rotary-type infrared sensor based measurement methods and devices. Finally, the system performance is compared and verified with the measurement data that have been obtained by practical field experiments.

Estimation of environmental external costs between coal fired power plant and nuclear power plant

International Nuclear Information System (INIS)

Moon, G. H.; Kim, S. S.

2000-01-01

First of all, this study evaluated the impacts on the health and the environment of air pollutants emitted from coal power plant and nuclear power pant, two major electric power generating options in Korea. Then, the environmental external costs of those two options were estimated by transforming the health and environment impact into monetary values. To do this, AIRPACTS and Impacts of Atmospheric Release model developed by IAEA were used. The environmental external cost of Samcheonpo coal power plant was estimated about 25 times as much as that of Younggwang nuclear power plant. This result implies that nuclear power plant is a clean technology compared with coal power plant. This study suggests that the external cost should be reflected in the electric system expansion plan in order to allocate energy resources efficiently and to reduce economic impact stemming from the environmental regulation emerged recently on a global level

Transformation, Conjugation, and Sequestration Following the Uptake of Triclocarban by Jalapeno Pepper Plants.

Science.gov (United States)

Huynh, Khang; Banach, Emily; Reinhold, Dawn

2018-04-25

Plant uptake and metabolism of emerging organic contaminants, such as personal-care products, pose potential risks to human health. In this study, jalapeno pepper ( Capsicum annuum) plants cultured in hydroponic media were exposed to both 14 C-labeled and unlabeled triclocarban (TCC) to investigate the accumulation, distribution, and metabolism of TCC following plant uptake. The results revealed that TCC was detected in all plant tissues; after 12 weeks, the TCC concentrations in root, stem, leaf, and fruit tissues were 19.74 ± 2.26, 0.26 ± 0.04, 0.11 ± 0.01, and 0.03 ± 0.01 mg/kg dry weight, respectively. More importantly, a substantial portion of the TCC taken up by plants was metabolized, especially in the stems, leaves, and fruits. Hydroxylated TCC (e.g., 2'-OH TCC and 6-OH TCC) and glycosylated OH-TCC were the main phase I and phase II metabolites in plant tissues, respectively. Bound (or nonextractable) residues of TCC accounted for approximately 44.6, 85.6, 69.0, and 47.5% of all TCC species that accumulated in roots, stems, leaves, and fruits, respectively. The concentrations of TCC metabolites were more than 20 times greater than the concentrations of TCC in the above-ground tissues of the jalapeno pepper plants after 12 weeks; crucially, approximately 95.6% of the TCC was present as metabolites in the fruits. Consequently, human exposure to TCC through the consumption of pepper fruits is expected to be substantially higher when phytometabolism is considered.

The effect of plant population and nitrogen fertilizer on

Directory of Open Access Journals (Sweden)

mohamad reza asgaripor

2009-06-01

Full Text Available Interest has increased towards hemp (Cannabis sativa L. fibre production due to renewed demand for natural fibre in the world. A Study was conducted in 2005 at Shirvan in Northern Khorasan province, Iran, to determine the effects of three plant populations (30, 90 and 150 plant per m2 and three rates of nitrogen application (50, 150 and 250 kg N per ha on final stand, stalk height, basal stalk diameter, total stalk yield as well as fibre content from stalk and fibre yield in male and female plants. A split plot experimental with three replications was used. The result indicated that due to enhanced competition for light at higher population on density and N2 level plant mortality was higher than other treatment Morphological characteristics were highly correlated with plant sexual, plant population and nitrogen fertilizer. Highest stem, leaf and inflorescence yield were obtained at 250 plant m-2 when 150 kg N ha-1 was used. Lowest plant density did not show self-thinning but reduced above ground dry matter. Shoot dry matter increased with increasing plant density and nitrogen supply. Apparently, fibre content was greater at medium density and lowest nitrogen fertilizer, however, fibre yield was greatest at highest plant population and nitrogen fertilizer. In terms of fibre yield, approximate 31.7% of the fibre was located in the bottom parts, 22.4% in the middle and only 9.9% in the top part of the stem. The results suggest that hemp can yield large quantities of useful fibre at Shirvan when planted in proper plant densities and suitable nitrogen fertilizer.

Stem and leaf anatomy of Plectranthus neochilus Schltr., Lamiaceae

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Márcia do Rocio Duarte

Full Text Available Plectranthus neochilus Schltr. is an aromatic herb named " boldo" or " boldo-gambá" and employed for treating hepatic insufficiency and dyspepsia in folk medicine. This paper has investigated its stem and leaf anatomy, in order to contribute for the medicinal plant identification. The botanical material was prepared according to standard microtechniques. The stem has quadrangular transection and, in secondary growth at the level analyzed, shows uniseriate epidermis and numerous trichomes. The glandular ones are capitate and peltate. The former has short unicellular or long multicellular stalk and uni- or bicellular head. The latter presents short stalk and eight-celled ovoid head. The non-glandular trichomes are multicellular, uniseriate and coated with granular cuticle. It is observed angular collenchyma, cambia forming phloem outward and xylem inward, and perivascular fiber caps next to the phloem. The blade has uniseriate epidermis coated with striate cuticle, diacytic stomata on both surfaces, numerous trichomes similar to the stem ones, and homogeneous mesophyll. The midrib shows one or two collateral bundles and the petiole has many of them distributed as an open arc.

Stem cells

NARCIS (Netherlands)

Jukes, Jojanneke; Both, Sanne; Post, Janine; van Blitterswijk, Clemens; Karperien, Marcel; de Boer, Jan; van Blitterswijk, Clemens A.

2008-01-01

This chapter defines stem cells and their properties. It identifies the major differences between embryonic and adult stem cells. Stem cells can be defined by two properties: the ability to make identical copies of themselves and the ability to form other cell types of the body. These properties are

Spatial distribution of xylem embolisms in the stems of Pinus thunbergii at the threshold of fatal drought stress.

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Umebayashi, Toshihiro; Morita, Toshimitsu; Utsumi, Yasuhiro; Kusumoto, Dai; Yasuda, Yuko; Haishi, Tomoyuki; Fukuda, Kenji

2016-10-01

Although previous studies have suggested that branch dieback and whole-plant death due to drought stress occur at 50-88% loss of stem hydraulic conductivity (P 50 and P 88 , respectively), the dynamics of catastrophic failure in the water-conducting pathways in whole plants subjected to drought remain poorly understood. We examined the dynamics of drought stress tolerance in 3-year-old Japanese black pine (Pinus thunbergii Parl.). We nondestructively monitored (i) the spatial distribution of drought-induced embolisms in the stem at greater than P 50 and (ii) recovery from embolisms following rehydration. Stem water distributions were visualized by cryo-scanning electron microscopy. The percentages of both embolized area and loss of hydraulic conductivity showed similar patterns of increase, although the water loss in xylem increased markedly at -5.0 MPa or less. One seedling that had reached 72% loss of the water-conducting area survived and the xylem water potential recovered to -0.3 MPa. We concluded that Japanese black pines may need to maintain water-filled tracheids within earlywood of the current-year xylem under natural conditions to avoid disconnection of water movement between the stem and the tops of branches. It is necessary to determine the spatial distribution of embolisms around the point of the lethal threshold to gain an improved understanding of plant survival under conditions of drought. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The accumulation of two neolignan in the leaves, stems, and flower of red betel (Piper crocatum Ruiz & Pav.)

Science.gov (United States)

Hartini, Y. S.; Nugroho, L.

2017-05-01

Organ for the biosynthesis of secondary metabolite is not always a place for its biosynthesis, even the same compound was synthesized in the different organs in different plants. Neolignan is a secondary metabolite, known as an imunostimulant, synthesized through shikimic acid pathway with the important precursor is chorismic acid. The compound was known to be accumulated in the roots, stems and leaves of Piper regnellii with the concentration varies depending on the type of neolignan. It has been investigated the accumulation of two compound neolignans (Pc-1 and Pc-2) isolated from the methanol extract of red betel leaf (Piper crocatum Ruiz & Pav.) in the leaves, stems, and flowers of red betel. Chromatographic methods used was Gas Chromatography-Mass Spectrometry (GC-MS). Chromatogram of GC-MS showed that the Pc-1 with purity of 100%, m/z 460.3 could be detected at the minute of 29.986, while the Pc-2 with purity of 96.681%, m/z 418.3 was detected at the minute of 29.495. The research was then continued to investigate the existence and accumulation of both compounds in leaves, stems, and flowers of red betel. The GC-MS chromatogram shows that Pc-1 and Pc-2 could be detected in the leaves, stem and flower with various concentration among plant organs. Moreover, leaves contained the highest concentration of Pc-1 and Pc-2 compared to other plant organs.

Ethnic variation in gender-STEM stereotypes and STEM participation: an intersectional approach.

Science.gov (United States)

O'Brien, Laurie T; Blodorn, Alison; Adams, Glenn; Garcia, Donna M; Hammer, Elliott

2015-04-01

Stereotypes associating men and masculine traits with science, technology, engineering, and mathematics (STEM) fields are ubiquitous, but the relative strength of these stereotypes varies considerably across cultures. The present research applies an intersectional approach to understanding ethnic variation in gender-STEM stereotypes and STEM participation within an American university context. African American college women participated in STEM majors at higher rates than European American college women (Study 1, Study 2, and Study 4). Furthermore, African American women had weaker implicit gender-STEM stereotypes than European American women (Studies 2-4), and ethnic differences in implicit gender-STEM stereotypes partially mediated ethnic differences in STEM participation (Study 2 and Study 4). Although African American men had weaker implicit gender-STEM stereotypes than European American men (Study 4), ethnic differences between men in STEM participation were generally small (Study 1) or nonsignificant (Study 4). We discuss the implications of an intersectional approach for understanding the relationship between gender and STEM participation. (c) 2015 APA, all rights reserved).

Natuculture Systems: Addressing Students' STEM and Agriculture Knowledge

Science.gov (United States)

Joyce, Alexander Augusto

The purpose of this study was to assess the inclusion of a Natuculture systems learning experience into selected high school STEM courses to determine high school students' interests in majoring in STEM and for pursuing careers in agricultural sciences. Natuculture is defined as "any human-made system that mimics nature in human-disturbed landscapes". The research occurred at an urban area high school located in the Piedmont region of North Carolina. Fifty-three students in grades 9-12 participated during an academic semester learning experience which included planting, maintenance, & harvesting for an oasissofa. Data was collected using a questionnaire and reflective journals to gather students' attitudes towards agriculture and science and knowledge towards agriculture. Results showed that while the experiences did not improve students' interest in pursuing careers in agricultural sciences, overall, they did increase their knowledge of concepts related to agriculture. It was concluded that students benefit from experiential learning experiences. Based on the study, it is recommended that future research follow up with students to learn of their educational and career choices in agriculture and future learning experiences include curricula that integrates agricultural topics with STEM courses.

Selection individual on mutant genotype of soybean (Glycine maxl.merrill) in m5 generation based on resistance of stem rot disease Athelia rolfsii (curzi)

Science.gov (United States)

Rahmah, M.; Hanafiah, D. S.; Siregar, L. A. M.; Safni, I.

2018-02-01

This study was aimed to obtain selected individuals on soybean plant Glycine max L. (Merrill) in M5 generation based on high production character and tolerance of stem rot disease Athelia rolfsii (Curzi). This research was conducted in Plant Disease Laboratory and experimental field Faculty of Agriculture Universitas Sumatera Utara Medan, Indonesia. This research was conducted from December 2016 to June 2017. The treatments were 15 mutant lines genotypes and Anjasmoro variety. The results showed that some lines mutant genotypes can gave the good agronomic appearance character than Anjasmoro variety on inoculation treatment of stem rot disease. Selection performed on population M5 producesselected individuals with tolerance of stem rot disease from 100 and 200 Gy population.

A Computer-Based Simulation for Teaching Heat Transfer across a Woody Stem

Science.gov (United States)

Maixner, Michael R.; Noyd, Robert K.; Krueger, Jerome A.

2010-01-01

To assist student understanding of heat transfer through woody stems, we developed an instructional package that included an Excel-based, one-dimensional simulation model and a companion instructional worksheet. Guiding undergraduate botany students to applying principles of thermodynamics to plants in nature is fraught with two main obstacles:…

Bromelain, a cysteine protease from pineapple (Ananas comosus) stem, is an inhibitor of fungal plant pathogens.

Science.gov (United States)

López-García, B; Hernández, M; Segundo, B S

2012-07-01

This study aimed to evaluate the effect of bromelain, a cysteine protease isolated from pineapple (Ananas comosus), on growth of several agronomically important fungal pathogens. Purification of bromelain from pineapple stems was carried out by chromatography techniques, and its antimicrobial activity was tested against the fungal pathogens Fusarium verticillioides, Fusarium oxysporum and Fusarium proliferatum by broth microdilution assay. A concentration of 0.3 μmol l(-1) of bromelain was sufficient for 90% growth inhibition of F. verticillioides. The capability of bromelain to inhibit fungal growth is related to its proteolytic activity. The study demonstrates that stem bromelain exhibits a potent antifungal activity against phytopathogens and suggests its potential use as an effective agent for crop protection. The results support the use of a natural protease that accumulates at high levels in pineapple stems as alternative to the use of chemical fungicides for crop protection. © 2012 The Authors. Letters in Applied Microbiology © 2012 The Society for Applied Microbiology.

Tritium in plants

International Nuclear Information System (INIS)

Vichot, L.; Losset, Y.

2009-01-01

The presence of tritium in the environment stems from its natural production by cosmic rays, from the fallout of the nuclear weapon tests between 1953 and 1964, and locally from nuclear industry activities. A part of the tritiated water contained in the foliage of plants is turned into organically bound tritium (OBT) by photosynthesis. The tritium of OBT, that is not exchangeable and then piles up in the plant, can be used as a marker of the past. It has been shown that the quantity of OBT contained in the age-rings of an oak that grew near the CEA center of Valduc was directly correlated with the tritium releases of the center. (A.C.)

Analysis of phytochemical variations in dioecious Tinospora cordifolia stems using HPLC/QTOF MS/MS and UPLC/QqQLIT -MS/MS.

Science.gov (United States)

Bajpai, Vikas; Singh, Awantika; Chandra, Preeti; Negi, M P S; Kumar, Nikhil; Kumar, Brijesh

2016-01-01

The stem of dioecious Tinospora cordifolia (Menispermaceae) is a commonly used traditional Ayurvedic medicine in India having several therapeutic properties. To develop and validate LC-MS methods for the identification and simultaneous quantitation of various secondary metabolites and to study metabolomic variations in the stem of male and female plants. Ethanolic extract of stems were analysed by HPLC/ESI-QTOF-MS/MS for rapid screening of bioactive phytochemicals. High resolution MS and MS/MS in positive ESI mode were used for structural investigation of secondary metabolites. An UPLC/ESI-QqQ(LIT) -MS/MS method in MRM mode was developed and validated for the simultaneous quantitation of five bioactive alkaloids. Identification and characterisation of 36 metabolites including alkaloids, sesquiterpenes and phytoecdysteroids were performed using LC-MS and MS/MS techniques. The bioactive alkaloids such as jatrorrhizine, magnoflorine, isocorydine, palmatine and tetrahydropalmatine were successfully quantified in male and female plants. The mean abundances of magnoflorine jatrorrhizine, and oblongine were significantly (P Phytochemicals in the stem of male and female Tinospora cordifolia showed significant qualitative and quantitative variations. LC-MS and MS/MS methods can be used to differentiate between male and female plants based on their chemical profiles and quantities of the marker bioactive alkaloids. This chemical composition difference was also evident during vegetative stage when there were no male and female flowers. Copyright © 2015 John Wiley & Sons, Ltd.

Effects of amendments on the uptake and distribution of DDT in Cucurbita pepo ssp pepo plants

Energy Technology Data Exchange (ETDEWEB)

Whitfield Aslund, Melissa L.; Lunney, Alissa I. [Department of Chemistry and Chemical Engineering, Royal Military College of Canada, Kingston, ON, K7K 7B4 (Canada); Rutter, Allison [School of Environmental Studies, Biosciences Complex, Queen' s University, Kingston, ON, K7L 3N6 (Canada); Zeeb, Barbara A., E-mail: zeeb-b@rmc.c [Department of Chemistry and Chemical Engineering, Royal Military College of Canada, Kingston, ON, K7K 7B4 (Canada)

2010-02-15

The effects of soil amendments on the phytoextraction of SIGMADDT (DDT + DDD + DDE) from soil ([SIGMADDT] approx 1500 ng/g) by a pumpkin variety of Cucurbita pepo ssp pepo were tested and the patterns of SIGMADDT storage throughout the plant shoot were examined. The soil amendments did not increase the total amount of SIGMADDT extracted into plant shoots, but new information about SIGMADDT distribution in the plants was obtained. As observed previously, the SIGMADDT concentration in plant leaves (mean 290 ng/g) was significantly lower than in plant stems (mean 2600 ng/g). Further analysis revealed that SIGMADDT composition was consistent throughout the plant shoot and that SIGMADDT concentration in leaves and stems decreased exponentially as distance from the root increased, which was previously unknown. This new information about the patterns of SIGMADDT uptake and translocation within pumpkin plants highlights the need for appropriate plant sampling strategies in future POPs phytoextraction research. - Patterns of SIGMADDT storage in a pumpkin plant are elucidated and specific surfactant and mycorrhizal soil amendments did not increase the total amount of SIGMADDT phytoextracted into plant shoots.

Learn About Stem Cells

Science.gov (United States)

... Patient Handbook Stem Cell Glossary Search Toggle Nav Stem Cell Basics Stem cells are the foundation from which ... original cell’s DNA, cytoplasm and cell membrane. About stem cells Stem cells are the foundation of development in ...

Preliminary screening of some traditional zulu medicinal plants for anti-inflammatory and anti-microbial activities.

Science.gov (United States)

Lin, J; Opoku, A R; Geheeb-Keller, M; Hutchings, A D; Terblanche, S E; Jäger, A K; van Staden, J

1999-12-15

Aqueous and methanolic extracts from different parts of nine traditional Zulu medicinal plants, of the Vitaceae from KwaZulu-Natal, South Africa were evaluated for therapeutic potential as anti-inflammatory and anti-microbial agents. Of the twenty-nine crude extracts assayed for prostaglandin synthesis inhibitors, only five methanolic extracts of Cyphostemma natalitium-root, Rhoicissus digitata-leaf, R. rhomboidea-root, R. tomentosa-leaf/stem and R. tridentata-root showed significant inhibition of cyclo-oxygenase (COX-1). The extracts of R. digitata-leaf and of R. rhomboidea-root exhibited the highest inhibition of prostaglandin synthesis with 53 and 56%, respectively. The results suggest that Rhoicissus digitata leaves and of Rhoicissus rhomboidea roots may have the potential to be used as anti-inflammatory agents. All the screened plant extracts showed some degrees of anti-microbial activity against gram-positive and gram-negative microorganisms. The methanolic extracts of C. natalitium-stem and root, R. rhomboidea-root, and R. tomentosa-leaf/stem, showed different anti-microbial activities against almost all micro-organisms tested. Generally, these plant extracts inhibited the gram-positive micro-organisms more than the gram-negative ones. Several plant extracts inhibited the growth of Candida albicans while only one plant extract showed inhibitory activity against Saccharomyces cerevisiae. All the plant extracts which demonstrated good anti-inflammatory activities also showed better inhibitory activity against Candida albicans.

Identification of Xylem Occlusions Occurring in Cut Clematis (Clematis L., fam. Ranunculaceae Juss. Stems during Their Vase Life

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Agata Jedrzejuk

2012-01-01

Full Text Available During the vase life of cut stems obstruction of xylem vessels occurs due to microbial growth, formation of tyloses, deposition of materials in the lumen of xylem vessels and the presence of air emboli in the vascular system. Such obstructions may restrict water uptake and its transport towards upwards thus lowering their ornamental value and longevity of cut flowers. Clematis is a very attractive plant material which may be used as cut flower in floral compositions. Nothing is known about the histochemical or cytological nature of xylem blockages occurring in cut stems of this plant. This study shows that in clematis, tyloses are the main source of occlusions, although bacteria and some amorphic substances may also appear inside the vessels. A preservative composed of 200 mg dm−3 8-HQC (8-hydroxyquinolin citrate and 2% sucrose arrested bacterial development and the growth of tyloses. This information can be helpful in the development of new treatments to improve keeping qualities of cut clematis stems.

Allelopathic Effects of Aqueous Extract of Leaf Stem and Root of Sorghum bicolor on Seed Germination and Seedling Growth of Vigna radiata L.

Directory of Open Access Journals (Sweden)

Amir MOOSAVI

2011-05-01

Full Text Available Seed germination under field conditions is highly influenced by the presence of other plants. Allelopathy is an important mechanism of plant competition, by producing phytotoxins to the plant environment in order to decline other plants growth. Soil sickness problem in farm lands is also known as an allelopathic effect or even autotoxicity. The toxicity of released allelochemicals by a plant in the environment is attributed to its function of concentration, age and metabolic stage. In this study we investigate the effect (5, 20, 35 and 50 g l-1 of leaf, stem and root water extract of sorghum on seed germination and seedling growth of mung bean. The results of the experiment showed that allelopathic effect of different concentrations was not significant for germination percentage, but germination rate and mean germination time decreased significantly by increasing the concentration of allelopathic extracts; also, there was a clear allelopathic effect of sorghum extract on seedling growth of mung bean. 50 g l-1 sorghum stem extract exhibited the highest inhibitory effect on root and shoot growth of mung bean. Among all parts of sorghum, stem extracts showed the highest allelopatic effect on seedling growth. Root extract showed higher inhibitory effect than leaf extracts.

Evaluation of the repellent and insecticidal activities of the leaf, stem ...

African Journals Online (AJOL)

Adults of C. maculatus were exposed to grains treated separately with the root, stem and leaf powders of C. odorata at different exposure periods of 12, 24, 36, and 48 hours. All the three plant parts significantly repelled C. maculatus with the root powder showing the highest percentage repellency, although this was a ...

Stem Cell Pathology.

Science.gov (United States)

Fu, Dah-Jiun; Miller, Andrew D; Southard, Teresa L; Flesken-Nikitin, Andrea; Ellenson, Lora H; Nikitin, Alexander Yu

2018-01-24

Rapid advances in stem cell biology and regenerative medicine have opened new opportunities for better understanding disease pathogenesis and the development of new diagnostic, prognostic, and treatment approaches. Many stem cell niches are well defined anatomically, thereby allowing their routine pathological evaluation during disease initiation and progression. Evaluation of the consequences of genetic manipulations in stem cells and investigation of the roles of stem cells in regenerative medicine and pathogenesis of various diseases such as cancer require significant expertise in pathology for accurate interpretation of novel findings. Therefore, there is an urgent need for developing stem cell pathology as a discipline to facilitate stem cell research and regenerative medicine. This review provides examples of anatomically defined niches suitable for evaluation by diagnostic pathologists, describes neoplastic lesions associated with them, and discusses further directions of stem cell pathology.

Another “M” for STEM? Moral Considerations for Advancing STEM Literacy

Directory of Open Access Journals (Sweden)

Sami Kahn

2015-10-01

Full Text Available Although workforce readiness is often cited as the primary rationale for STEM education, a broader view of scientific literacy, one that envisions students as members of an informed citizenry able to reason thoughtfully and ethically through increasingly complex STEM issues, seems warranted. To that end, this position paper advances the argument that STEM, particularly with the incorporation of engineering in the Next Generation Science Standards (U.S., must serve as a context for moral development by expanding student argumentation and discourse to include the moral and ethical consequences of STEM decision making. In addition, STEM is positioned as an ideal domain for inclusivity, capable of advancing a more just and equitable society through broader engagement and participation. To illustrate how these visions might be realized in the classroom, the author transforms a typical STEM lesson into a “moral” STEM lesson through the incorporation of two curricular frameworks, Socioscientific Issues (SSI and Universal Design for Learning (UDL. The purpose of this exercise is to demonstrate the manner in which STEM content and practices can be preserved and enhanced while widening curricular objectives to include the development of an informed, reflective, and inclusive STEM-literate citizenry.

Identification of cell wall proteins in the flax (Linum usitatissimum) stem.

Science.gov (United States)

Day, Arnaud; Fénart, Stéphane; Neutelings, Godfrey; Hawkins, Simon; Rolando, Christian; Tokarski, Caroline

2013-03-01

Sequential salt (CaCl2 , LiCl) extractions were used to obtain fractions enriched in cell wall proteins (CWPs) from the stem of 60-day-old flax (Linum usitatissimum) plants. High-resolution FT-ICR MS analysis and the use of recently published genomic data allowed the identification of 11 912 peptides corresponding to a total of 1418 different proteins. Subcellular localization using TargetP, Predotar, and WoLF PSORT led to the identification of 152 putative flax CWPs that were classified into nine different functional classes previously established for Arabidopsis thaliana. Examination of different functional classes revealed the presence of a number of proteins known to be involved in, or potentially involved in cell-wall metabolism in plants. The flax stem cell wall proteome was also compared with transcriptomic data previously obtained on comparable samples. This study represents a major contribution to the identification of CWPs in flax and will lead to a better understanding of cell wall biology in this species. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Stem infusion of nitrogen-15 to quantify nitrogen remobilization in maize

International Nuclear Information System (INIS)

Ma, B.L.; Dwyer, L.M.; Tollenaar, M.; Smith, D.L.

1998-01-01

Nitrogen (N) use efficiency (NUE) of fertilizer N can be accurately estimated by tracing the fate of soil applied labelled fertilizer, but the quantity of N remobilization from non-kernel components into kernels in maize (Zea mays L.) plants is difficult to determine. A field experiment involving stem infusion with labelled 15N solution was conducted at Ottawa, Ontario (45 degrees 22'N, 75 degrees 43'W) for two years to determine whether stem infused 15N could be used to quantify N remobilization and the contribution of remobilized N to the grain. A current stay-green commercial hybrid was grown at three fertilizer N rates and infused with 30 mL 15N solution [35.7 mmol N as 15NH(4)15NO(3) at 99.2 15N% atom enrichment (a.e.)] into the internode below the primary cob at anthesis. The control plants were infused with distilled water. Sampling occurred at 3 d, 2 wk and 5 wk after anthesis and at physiological maturity

The bio-positive effects of diagnostic doses of X-rays on growth of phaseolus-vulgaris plant

Energy Technology Data Exchange (ETDEWEB)

Mortazavi, S.M.J.; Mehdipour, L.A.; Behnejad, B.B. [Rafsanjan Univ. of Medical Sciences (Iran, Islamic Republic of)

2006-07-01

Objective: Plants absorb radioactive elements from phosphate fertilizers, and also from naturally occurring radiation in the soil, air and water. It has long been known that low doses of ionizing radiation evoke stimulatory effects in a wide variety of living organisms. However, as far as we know, there is no published report on the bio-positive effects of diagnostic doses of X-rays on plant growth. The aim of this study was to evaluate the bio-effects of low doses of diagnostic X-rays on growth rate of Phaseolus vulgaris (Pinto) plants. Materials and Methods: Before cultivation, Phaseolus vulgaris (Pinto) seeds were soaked in tap water for 2 days followed by another 2 days of covering under a wet cloth. Four hundred newly cultivated seeds were randomly divided into two groups of 200 plants each. In this experiment, two seeds were cultivated in each dish (100 dishes for irradiation group and 100 for sham-irradiation group). Fifteen days after starting cultivation, newly grown plants were irradiated with X-rays. Plants were exposed to a single dose of X-ray (80 kVp, 80 mAs) for 6 days. On day 29, plants were pulled out from the ' soil. Length of plant stem, length of root, number of leaves and plant weight were measured. Results: The stem length in irradiated and sham-irradiated plants was 296.5{+-}13.57 and 223.96{+-}15.02 mm respectively. This difference was statistically significant (P<0.001). Although the number of leaves in irradiated plants was higher than that of sham-irradiated plants (7.05{+-}0.18 and 6.74{+-}0.19 respectively), the difference was not statistically significant. The stem diameter in irradiated and sham-irradiated plants were 3.52{+-}0.12 and 3.35{+-}0.09 mm respectively, but the difference again was not statistically significant (P<0.00 1). Plant weight in irradiated samples was less than that of non-irradiated plants but it was not statistically significant. Conclusions: The overall results indicate that diagnostic doses of X-rays can

Eckol suppresses maintenance of stemness and malignancies in glioma stem-like cells

International Nuclear Information System (INIS)

Hyun, Kyung-Hwan; Yoon, Chang-Hwan; Kim, Rae-Kwon; Lim, Eun-Jung; An, Sungkwan; Park, Myung-Jin; Hyun, Jin-Won; Suh, Yongjoon; Kim, Min-Jung; Lee, Su-Jae

2011-01-01

A subpopulation of cancer cells with stem cell properties is responsible for tumor maintenance and progression, and may contribute to resistance to anticancer treatments. Thus, compounds that target cancer stem-like cells could be usefully applied to destroy cancer. In this study, we investigated the effect of Eckol, a phlorotannin compound, on stemness and malignancies in glioma stem-like cells. To determine whether Eckol targets glioma stem-like cells, we examined whether Eckol treatment could change the expression levels of glioma stem-like cell markers and self-renewal-related proteins as well as the sphere forming ability, and the sensitivity to anticancer treatments. Alterations in the malignant properties of sphere-derived cells by Eckol were also investigated by soft-agar colony forming assay, by xenograft assay in nude mice, and by cell invasion assay. Treatment of sphere-forming glioma cells with Eckol effectively decreased the sphere formation as well as the CD133 + cell population. Eckol treatment suppressed expression of the glioma stem-like cell markers and the self-renewal-related proteins without cell death. Moreover, treatment of glioma stem-like cells with Eckol significantly attenuated anchorage-independent growth on soft agar and tumor formation in xenograft mice. Importantly, Eckol treatment effectively reduced the resistance of glioma stem-like cells to ionizing radiation and temozolomide. Treatment of glioma stem-like cells with Eckol markedly blocked both phosphoinositide 3-kinase-Akt and Ras-Raf-1-Erk signaling pathways. These results indicate that the natural phlorotannin Eckol suppresses stemness and malignancies in glioma stem-like cells, and thereby makes glioma stem-like cells more sensitive to anticancer treatments, providing novel therapeutic strategies targeting specifically cancer stem-like cells.

Sugar Transporters in Plants: New Insights and Discoveries.

Science.gov (United States)

Julius, Benjamin T; Leach, Kristen A; Tran, Thu M; Mertz, Rachel A; Braun, David M

2017-09-01

Carbohydrate partitioning is the process of carbon assimilation and distribution from source tissues, such as leaves, to sink tissues, such as stems, roots and seeds. Sucrose, the primary carbohydrate transported long distance in many plant species, is loaded into the phloem and unloaded into distal sink tissues. However, many factors, both genetic and environmental, influence sucrose metabolism and transport. Therefore, understanding the function and regulation of sugar transporters and sucrose metabolic enzymes is key to improving agriculture. In this review, we highlight recent findings that (i) address the path of phloem loading of sucrose in rice and maize leaves; (ii) discuss the phloem unloading pathways in stems and roots and the sugar transporters putatively involved; (iii) describe how heat and drought stress impact carbohydrate partitioning and phloem transport; (iv) shed light on how plant pathogens hijack sugar transporters to obtain carbohydrates for pathogen survival, and how the plant employs sugar transporters to defend against pathogens; and (v) discuss novel roles for sugar transporters in plant biology. These exciting discoveries and insights provide valuable knowledge that will ultimately help mitigate the impending societal challenges due to global climate change and a growing population by improving crop yield and enhancing renewable energy production. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

A new Late Devonian genus with seed plant affinities.

Science.gov (United States)

Wang, Deming; Liu, Le

2015-02-26

Many ovules of Late Devonian (Famennian) seed plants have been well studied. However, because few taxa occur with anatomically preserved stems and/or petioles, the vascular system of these earliest spermatophytes is little understood and available data come mostly from Euramerica. There remains great controversy over the anatomical differentiation of Late Devonian and Carboniferous seed plant groups of Buteoxylonales, Calamopityales and Lyginopteridales. Protostele evolution of these early spermatophytes needs more research. A new taxon Yiduxylon trilobum gen. et sp. nov. with seed plant affinities has been discovered in the Upper Devonian (Famennian) Tizikou Formation of Hubei Province, China. It is represented by stems, helically arranged and bifurcate fronds with two orders of pinnae and planate pinnules. Both secondary pinnae and pinnules are borne alternately. Stems contain a small protostele with three primary xylem ribs possessing a single peripheral protoxylem strand. Thick secondary xylem displays multiseriate bordered pitting on the tangential and radial walls of the tracheids, and has biseriate to multiseriate and high rays. A narrow cortex consists of inner cortex without sclerotic nests and sparganum-type outer cortex with peripheral bands of vertically aligned sclerenchyma cells. Two leaf traces successively arise tangentially from each primary xylem rib and they divide once to produce four circular-oval traces in the stem cortex. Four vascular bundles occur in two C-shaped groups at each petiole base with ground tissue and peripheral bands of sclerenchyma cells. Yiduxylon justifies the assignment to a new genus mainly because of the protostele with protoxylem strands only near the periphery of primary xylem ribs, leaf trace origination and petiolar vascular supply structure. It shares many definitive characters with Calamopityales and Lyginopteridales, further underscoring the anatomical similarities among early seed plants. The primary vascular

Haematopoietic stem and progenitor cells from human pluripotent stem cells

Science.gov (United States)

Sugimura, Ryohichi; Jha, Deepak Kumar; Han, Areum; Soria-Valles, Clara; da Rocha, Edroaldo Lummertz; Lu, Yi-Fen; Goettel, Jeremy A.; Serrao, Erik; Rowe, R. Grant; Malleshaiah, Mohan; Wong, Irene; Sousa, Patricia; Zhu, Ted N.; Ditadi, Andrea; Keller, Gordon; Engelman, Alan N.; Snapper, Scott B.; Doulatov, Sergei; Daley, George Q.

2018-01-01

A variety of tissue lineages can be differentiated from pluripotent stem cells by mimicking embryonic development through stepwise exposure to morphogens, or by conversion of one differentiated cell type into another by enforced expression of master transcription factors. Here, to yield functional human haematopoietic stem cells, we perform morphogen-directed differentiation of human pluripotent stem cells into haemogenic endothelium followed by screening of 26 candidate haematopoietic stem-cell-specifying transcription factors for their capacity to promote multi-lineage haematopoietic engraftment in mouse hosts. We recover seven transcription factors (ERG, HOXA5, HOXA9, HOXA10, LCOR, RUNX1 and SPI1) that are sufficient to convert haemogenic endothelium into haematopoietic stem and progenitor cells that engraft myeloid, B and T cells in primary and secondary mouse recipients. Our combined approach of morphogen-driven differentiation and transcription-factor-mediated cell fate conversion produces haematopoietic stem and progenitor cells from pluripotent stem cells and holds promise for modelling haematopoietic disease in humanized mice and for therapeutic strategies in genetic blood disorders. PMID:28514439

Study on caralluma tuberculata nutritional composition and its importance as medicinal plant

International Nuclear Information System (INIS)

Ahmad, B.; Abbasi, S.J.; Hussain, F.

2014-01-01

This study was conducted on Caralluma tuberculata, a famous traditional medicinal plant in the northern territory of Pakistan to assess its importance. Analysis were performed on its nutritional, proximate and microchemical composition for evaluation as food plant, while experiments of cytotoxicity, phytotoxicity and as phytobiocide were conducted to study its importance as medicinal plant. A method for vegetative propagation of C. tuberculata was optimized using cut stems without roots give better result and also more economical, from single stem multiple plant can be produced. It contains good amount of nutrients and proximate contents. Due to high inhibitory effect results of C. tuberculata against Alternaria alternata it can be recommended as selective fungicide for controlling Alternaria sp., born diseases. From the results it becomes clear that C. tuberculata had some anti-bacterial compounds which had very minimum inhibitory effect on the growth of bacterial species. This plant also showed significant activity against Artemia salina, Lemna minor and can be used as cytotoxic and phytotoxic agents in concentrated states. (author)

Sphagnum growth in floating cultures: Effect of planting design

Directory of Open Access Journals (Sweden)

Y. Hoshi

2017-11-01

Full Text Available To establish rapid and stable Sphagnum growth, capitulum culture of a selected strain of S. palustre was carried out using a floating culture method. Four planting treatments were tested at mountain and urban sites in Kumamoto Prefecture on Kyushu Island, south-west Japan. Capitula were planted in colonies of different sizes on 30 cm square floating rafts, but with strict control of the number (75–77 of capitula per raft. The initial cover of live green Sphagnum ranged from 15 to 20 %. Growth of the colonies was followed throughout the growing season (April to November of 2008. After three months, green coverage rates reached 40–50 % in all planting treatments. At the end of the growing season, the highest Sphagnum cover (almost 90 % at the urban site was recorded in the planting treatment with eleven re-introduced colonies of seven capitula (‘11×7cap’, while the highest capitulum number and biomass (dry weight gain occurred in the ‘4×19cap’ planting treatment. Average stem elongation ranged from 5 cm to 7 cm in the ‘77×1cap’ and ‘4×19cap’planting treatments, respectively, indicating that the larger sized colony grew longer stems. However, contrary to expectation, the ‘4×19cap’planting treatment - which had the largest colony size - did not deliver the highest number of newly formed side shoots.

Fake news portrayals of stem cells and stem cell research.

Science.gov (United States)

Marcon, Alessandro R; Murdoch, Blake; Caulfield, Timothy

2017-10-01

This study examines how stem cells and stem cell research are portrayed on websites deemed to be purveyors of distorted and dubious information. Content analysis was conducted on 224 articles from 2015 to 2016, compiled by searching with the keywords 'stem cell(s)' on a list of websites flagged for containing either 'fake' or 'junk science' news. Articles contained various exaggerated positive and negative claims about stem cells and stem cell science, health and science related conspiracy theories, and statements promoting fear and mistrust of conventional medicine. Findings demonstrate the existence of organized misinformation networks, which may lead the public away from accurate information and facilitate a polarization of public discourse.

In vitro regenerative potentials of the medicinal plant Abutilon ...

African Journals Online (AJOL)

Nissar Reshi

2016-03-23

Mar 23, 2016 ... ... Hodiyala Vasanaika. Plant Tissue Culture Laboratory, Department of Studies in Botany, University of Mysore, Manasagangotri, ... explants like shoot tip, axillary buds, stem cuttings and .... strand at the base of the embryoid.

Inheritance of Hairiness of Stem and Petiole in a Selection from Local (Nigeria Germoplasm of Sesame

Directory of Open Access Journals (Sweden)

Funmi, FM.

2002-01-01

Full Text Available Character differences were studied in inter specific crosses involving Sesamum indicum L. and Ceratotheca sesamoides Endl. Results show that inheritance of many hairs on stem and petiole was controlled by two independently assorting genes with both dominant alleles S- and P- producing many hairs in stem and petiole respectively. Only the genotypes sspp homozygous for both recessive alleles were plants with few hairs. The implications of these findings in the species evolution are discussed.

Cuticle ultrastructure, cuticular lipid composition, and gene expression in hypoxia-stressed Arabidopsis stems and leaves.

Science.gov (United States)

Kim, Hyojin; Choi, Dongsu; Suh, Mi Chung

2017-06-01

An increased permeability of the cuticle is closely associated with downregulation of genes involved in cuticular lipid synthesis in hypoxia-stressed Arabidopsis and may allow plants to cope with oxygen deficiency. The hydrophobic cuticle layer consisting of cutin polyester and cuticular wax is the first barrier to protect the aerial parts of land plants from environmental stresses. In the present study, we investigated the role of cuticle membrane in Arabidopsis responses to oxygen deficiency. TEM analysis showed that the epidermal cells of hypoxia-treated Arabidopsis stems and leaves possessed a thinner electron-translucent cuticle proper and a more electron-dense cuticular layer. A reduction in epicuticular wax crystal deposition was observed in SEM images of hypoxia-treated Arabidopsis stem compared with normoxic control. Cuticular transpiration was more rapid in hypoxia-stressed leaves than in normoxic control. Total wax and cutin loads decreased by approximately 6-12 and 12-22%, respectively, and the levels of C29 alkanes, secondary alcohols, and ketones, C16:0 ω-hydroxy fatty acids, and C18:2 dicarboxylic acids were also prominently reduced in hypoxia-stressed Arabidopsis leaves and/or stems relative to normoxic control. Genome-wide transcriptome and quantitative RT-PCR analyses revealed that the expression of several genes involved in the biosynthesis and transport of cuticular waxes and cutin monomers were downregulated more than fourfold, but no significant alterations were detected in the transcript levels of fatty acid biosynthetic genes, BCCP2, PDH-E1α, and ENR1 in hypoxia-treated Arabidopsis stems and leaves compared with normoxic control. Taken together, an increased permeability of the cuticle is closely associated with downregulation of genes involved in cuticular lipid synthesis in hypoxia-stressed Arabidopsis. The present study elucidates one of the cuticle-related adaptive responses that may allow plants to cope with low oxygen levels.

The accumulation of two neolignan in the leaves, stems, and flower of red betel ( Piper crocatum Ruiz and Pav.)

International Nuclear Information System (INIS)

Hartini, Y S; Nugroho, L

2017-01-01

Organ for the biosynthesis of secondary metabolite is not always a place for its biosynthesis, even the same compound was synthesized in the different organs in different plants. Neolignan is a secondary metabolite, known as an imunostimulant, synthesized through shikimic acid pathway with the important precursor is chorismic acid. The compound was known to be accumulated in the roots, stems and leaves of Piper regnellii with the concentration varies depending on the type of neolignan. It has been investigated the accumulation of two compound neolignans (Pc-1 and Pc-2) isolated from the methanol extract of red betel leaf ( Piper crocatum Ruiz and Pav.) in the leaves, stems, and flowers of red betel. Chromatographic methods used was Gas Chromatography-Mass Spectrometry (GC-MS). Chromatogram of GC-MS showed that the Pc-1 with purity of 100%, m/z 460.3 could be detected at the minute of 29.986, while the Pc-2 with purity of 96.681%, m/z 418.3 was detected at the minute of 29.495. The research was then continued to investigate the existence and accumulation of both compounds in leaves, stems, and flowers of red betel. The GC-MS chromatogram shows that Pc-1 and Pc-2 could be detected in the leaves, stem and flower with various concentration among plant organs. Moreover, leaves contained the highest concentration of Pc-1 and Pc-2 compared to other plant organs. (paper)

College Students' Conceptions of Stem Cells, Stem Cell Research, and Cloning

Science.gov (United States)

Concannon, James P.; Siegel, Marcelle A.; Halverson, Kristy; Freyermuth, Sharyn

2010-01-01

In this study, we examined 96 undergraduate non-science majors' conceptions of stem cells, stem cell research, and cloning. This study was performed at a large, Midwest, research extensive university. Participants in the study were asked to answer 23 questions relating to stem cells, stem cell research, and cloning in an on-line assessment before…

Gastric stem cells and gastric cancer stem cells

OpenAIRE

Han, Myoung-Eun; Oh, Sae-Ock

2013-01-01

The gastric epithelium is continuously regenerated by gastric stem cells, which give rise to various kinds of daughter cells, including parietal cells, chief cells, surface mucous cells, mucous neck cells, and enteroendocrine cells. The self-renewal and differentiation of gastric stem cells need delicate regulation to maintain the normal physiology of the stomach. Recently, it was hypothesized that cancer stem cells drive the cancer growth and metastasis. In contrast to conventional clonal ev...

Biomass production and control of nutrient leaching of willows using different planting methods with special emphasis on an appraisal of the electrical impedance for roots

Energy Technology Data Exchange (ETDEWEB)

Yang Cao

2011-07-01

Willow reproduction can be achieved through vertically or horizontally planted cuttings. Conventionally, plantations are established by inserting cuttings vertically into the soil. There is, however, a lack of information about the biomass production and nutrient leaching of plantations established through horizontally planted cuttings. A greenhouse experiment and a field trial were carried out to investigate whether horizontally planted Salix schwerinii cuttings have a positive effect on stem yield, root distribution and nutrient leaching in comparison with vertically planted cuttings with different planting densities. The shoots' height of horizontally planted cuttings was significantly smaller than that of vertically planted cuttings during the first two weeks after planting in the pot experiment. Thereafter, no significant effect of planting orientation on the stem biomass was observed in the two conducted experiments. In both experiments the total stem biomass increased with the planting density. It was also found that the fine root biomass and the specific root length were not affected by the planting orientation or density, while the fine root surface area and the absorbing root surface area (ARSA) were affected only by the planting density. The planting orientation did not affect the nutrient concentrations in the soil leachate, apart from SO{sub 4}-S and PO{sub 4}-P in the pot experiment. The ARSA in the pot experiment was assessed by using the earth impedance method. The applicability of this method was evaluated in a hydroponic study of willow cuttings where root and stem were measured independently. Electrical resistance had a good correlation with the contact area of the roots with the solution. However, the resistance depended strongly on the contact area of the stem with the solution, which caused a bias in the evaluation of root surface area. A similar experimental set-up with electrical impedance spectroscopy was employed to study the

Obstruction of Water Uptake in cut Chrysanthemum Stems after Dry Storage: Role of Wound-induced Increase in Enzyme Activities and Air Emboli

NARCIS (Netherlands)

Meeteren, van U.; Arevalo-Galarza, L.

2009-01-01

Hydraulic conductance of cut chrysanthemum stems was lowered by the aspiration of air as well as by a wound-induced plant response. By measuring the hydraulic conductance of stem segments in which air could be introduced into and/or removed from the xylem vessels at various times after harvest, we

The influence of aqueous leaf and stem extracts of Adenia lobata ...

African Journals Online (AJOL)

USER

2010-05-31

May 31, 2010 ... The concentration of the extracts affected the rate of effects of the extracts on the flowering and fruiting of the ... and stem extracts of A. lobata on the flowering and fruiting of ... using a sensitive electric balance. ... length (cm) of the fruit of okra (A. exculenta) and groundnut (A. hypoea). ... Plant Cell Physiol.

Muscle Stem Cells: A Model System for Adult Stem Cell Biology.

Science.gov (United States)

Cornelison, Ddw; Perdiguero, Eusebio

2017-01-01

Skeletal muscle stem cells, originally termed satellite cells for their position adjacent to differentiated muscle fibers, are absolutely required for the process of skeletal muscle repair and regeneration. In the last decade, satellite cells have become one of the most studied adult stem cell systems and have emerged as a standard model not only in the field of stem cell-driven tissue regeneration but also in stem cell dysfunction and aging. Here, we provide background in the field and discuss recent advances in our understanding of muscle stem cell function and dysfunction, particularly in the case of aging, and the potential involvement of muscle stem cells in genetic diseases such as the muscular dystrophies.

EFFECT OF TIDIAZURON AND DIETHILENTRIAMINE ON GAMMA-IRRADIATED OATS AND TRITICALE PLANTS

Directory of Open Access Journals (Sweden)

Nevena STOEVA

2001-09-01

Full Text Available The potential modifying effect of the synthetic growth regulators Tidiazuron and poliamine diethilentriamine, applied after gamma-irradiation stress on oats and triticale plants, was studied. Pot vegetative experiments with spring oats, cultivar Hanza 152, and triticale, cultivar 7251, were carried out. The plants were grown under controlled conditions and in the phase of stem extension they were irradiated with Cesium- 137 gamma rays, at a dose rate of 6 Gy (oats, and 4 Gy (triticale, and dose intensity of 2 Gy/min. On the day after the irradiation the plants were sprayed with a radioprotector for the purpose of decreasing the radiation damage. Two types of protectors were tested: tidiazuron and diethilenthriamine. The irradiation of oats and triticale plants in the phase of stem extension caused stress, which was detected by the disorganization of the cardinal physiological processes. The tested synthetic plant growth regulators reduced the negative effect of the irradiation. The peroxidase activity and the lipid peroxidation were reduced, while the plant productivity and the photosynthetic pigments were increased, both photosynthesis and transpiration activation were increased. Independently of the similar effect of both of the substances, polyamine DETA was characterized with a better modifying effect.

A Bistable Circuit Involving SCARECROW-RETINOBLASTOMA Integrates Cues to Inform Asymmetric Stem Cell Division

Science.gov (United States)

Cruz-Ramírez, Alfredo; Díaz-Triviño, Sara; Blilou, Ikram; Grieneisen, Verônica A.; Sozzani, Rosangela; Zamioudis, Christos; Miskolczi, Pál; Nieuwland, Jeroen; Benjamins, René; Dhonukshe, Pankaj; Caballero-Pérez, Juan; Horvath, Beatrix; Long, Yuchen; Mähönen, Ari Pekka; Zhang, Hongtao; Xu, Jian; Murray, James A.H.; Benfey, Philip N.; Bako, Laszlo; Marée, Athanasius F.M.; Scheres, Ben

2012-01-01

SUMMARY In plants, where cells cannot migrate, asymmetric cell divisions (ACDs) must be confined to the appropriate spatial context. We investigate tissue-generating asymmetric divisions in a stem cell daughter within the Arabidopsis root. Spatial restriction of these divisions requires physical binding of the stem cell regulator SCARECROW (SCR) by the RETINOBLASTOMA-RELATED (RBR) protein. In the stem cell niche, SCR activity is counteracted by phosphorylation of RBR through a cyclinD6;1-CDK complex. This cyclin is itself under transcriptional control of SCR and its partner SHORT ROOT (SHR), creating a robust bistable circuit with either high or low SHR-SCR complex activity. Auxin biases this circuit by promoting CYCD6;1 transcription. Mathematical modeling shows that ACDs are only switched on after integration of radial and longitudinal information, determined by SHR and auxin distribution, respectively. Coupling of cell-cycle progression to protein degradation resets the circuit, resulting in a “flip flop” that constrains asymmetric cell division to the stem cell region. PMID:22921914

Limbal Stem Cell Deficiency and Treatment with Stem Cell Transplantation.

Science.gov (United States)

Barut Selver, Özlem; Yağcı, Ayşe; Eğrilmez, Sait; Gürdal, Mehmet; Palamar, Melis; Çavuşoğlu, Türker; Ateş, Utku; Veral, Ali; Güven, Çağrı; Wolosin, Jose Mario

2017-10-01

The cornea is the outermost tissue of the eye and it must be transparent for the maintenance of good visual function. The superficial epithelium of the cornea, which is renewed continuously by corneal stem cells, plays a critical role in the permanence of this transparency. These stem cells are localized at the cornea-conjunctival transition zone, referred to as the limbus. When this zone is affected/destroyed, limbal stem cell deficiency ensues. Loss of limbal stem cell function allows colonization of the corneal surface by conjunctival epithelium. Over 6 million people worldwide are affected by corneal blindness, and limbal stem cell deficiency is one of the main causes. Fortunately, it is becoming possible to recover vision by autologous transplantation of limbal cells obtained from the contralateral eye in unilateral cases. Due to the potential risks to the donor eye, only a small amount of tissue can be obtained, in which only 1-2% of the limbal epithelial cells are actually limbal stem cells. Vigorous attempts are being made to expand limbal stem cells in culture to preserve or even enrich the stem cell population. Ex vivo expanded limbal stem cell treatment in limbal stem cell deficiency was first reported in 1997. In the 20 years since, various protocols have been developed for the cultivation of limbal epithelial cells. It is still not clear which method promotes effective stem cell viability and this remains a subject of ongoing research. The most preferred technique for limbal cell culture is the explant culture model. In this approach, a small donor eye limbal biopsy is placed as an explant onto a biocompatible substrate (preferably human amniotic membrane) for expansion. The outgrowth (cultivated limbal epithelial cells) is then surgically transferred to the recipient eye. Due to changing regulations concerning cell-based therapy, the implementation of cultivated limbal epithelial transplantation in accordance with Good Laboratory Practice using

Effects of nutrient omission in Caesalpinia echinata plants

Directory of Open Access Journals (Sweden)

Sergio Valiengo Valeri

2014-03-01

Full Text Available The objective of this study was to evaluate the growth, the morphological alterations and the mineral composition of brazilwood (Caesalpinia echinata plants caused by mineral nutrients omission in a green house experiment. The experimental units were distributed in the green house according to a completely random design. The treatments, each repeated five times, were the following : check (natural soil, complete (N, P, K, Ca, Mg, S, B, Cu, Mn, and Zn and a complete solution but for the omission of one of the nutrients in parenthesis. Each plot was represented by a plant growing in a 7 dm3 vase filled with Quartzarenic Neosol. The analyzed variables were the following: visual nutritional deficiency symptoms, plant height, stem diameter, shoot dry matter, stem, branches and leaves included, and leaf nutrients level. The omission of nitrogen limited plant growth in height and shoot biomass production. The first visual deficiency symptoms were those due to N omission followed by those caused by P, Ca, Mg, S, Cu, and Mn omissions. Later on the K and B deficiency symptoms became visible. The omission of a nutrient always caused its level in the leaves to be significantly lower than that found when it was not omitted.

High endemism and stem density distinguish New Caledonian from other high-diversity rainforests in the Southwest Pacific.

Science.gov (United States)

Ibanez, Thomas; Blanchard, E; Hequet, V; Keppel, G; Laidlaw, M; Pouteau, R; Vandrot, H; Birnbaum, P

2018-01-25

The biodiversity hotspot of New Caledonia is globally renowned for the diversity and endemism of its flora. New Caledonia's tropical rainforests have been reported to have higher stem densities, higher concentrations of relictual lineages and higher endemism than other rainforests. This study investigates whether these aspects differ in New Caledonian rainforests compared to other high-diversity rainforests in the Southwest Pacific. Plants (with a diameter at breast height ≥10 cm) were surveyed in nine 1-ha rainforest plots across the main island of New Caledonia and compared with 14 1-ha plots in high-diversity rainforests of the Southwest Pacific (in Australia, Fiji, Papua New Guinea and the Solomon Islands). This facilitated a comparison of stem densities, taxonomic composition and diversity, and species turnover among plots and countries. The study inventoried 11 280 stems belonging to 335 species (93 species ha-1 on average) in New Caledonia. In comparison with other rainforests in the Southwest Pacific, New Caledonian rainforests exhibited higher stem density (1253 stems ha-1 on average) including abundant palms and tree ferns, with the high abundance of the latter being unparalleled outside New Caledonia. In all plots, the density of relictual species was ≥10 % for both stems and species, with no discernible differences among countries. Species endemism, reaching 89 % on average, was significantly higher in New Caledonia. Overall, species turnover increased with geographical distance, but not among New Caledonian plots. High stem density, high endemism and a high abundance of tree ferns with stem diameters ≥10 cm are therefore unique characteristics of New Caledonian rainforests. High endemism and high spatial species turnover imply that the current system consisting of a few protected areas is inadequate, and that the spatial distribution of plant species needs to be considered to adequately protect the exceptional flora of New Caledonian rainforests

Antimicrobial screening of some medicinal plants from Mato Grosso Cerrado

Directory of Open Access Journals (Sweden)

Iberê E Silva Junior

Full Text Available Hexane, dichloromethane, ethyl acetate and ethanol extracts from stem barks of Bowdichia virgilioides, Calophyllum brasiliense, Cariniana rubra, Lafoensia pacari, and Stryphnodendron obovatum and rhizome of Simaba ferruginea and Dragon's blood red sap from Croton urucurana were screened against a panel of bacteria and fungi using the micro-broth dilution method. Dragon's blood from Croton urucurana was the most effective antimicrobial plant material. Ethyl acetate and hexane extracts of Calophyllum brasiliense stem bark deserved distinction by their selective antibacterial activity. Lafoensia pacari stem bark polar extracts distinguished by their potent and selective anti-yeast activity and Bowdichia virgilioides polar and non-polar extracts by their antifungal activity towards hyalohypho-mycetes and dermatophytes. This is the first report showing antifungal activity for polar extracts of Cariniana rubra and Simaba ferruginea. This study has demonstrated antimicrobial activity of Mato Grosso Cerrado ethnomedicinal plants in in vitro assays and has indicated that they can be effective potential candidates for the development of new strategies to treat fungal and bacterial infections.

Pre-anthesis high temperature acclimation alleviates the negative effects of postanthesis heat stress on stem stored carbohydrates remobilization and grain starch accumulation in wheat

DEFF Research Database (Denmark)

Wang, Xiao; Cai, Jian; Liu, Fulai

2012-01-01

The potential role of pre-anthesis high temperature acclimation in alleviating the negative effects of post-anthesis heat stress on stem stored carbohydrate remobilization and grain starch accumulation in wheat was investigated. The treatments included no heat-stress (CC), heat stress at pre...... had much higher starch content, and caused less modified B-type starch granule size indicators than the CH plants. Our results indicated that, compared with the non-acclimated plants, the pre-anthesis high temperature acclimation effectively enhanced carbohydrate remobilization from stems to grains...

Impact of field dodder (Cuscuta campestris Yunk. on physiological and anatomical changes in untreated and herbicide-treated alfalfa plants

Directory of Open Access Journals (Sweden)

Sarić-Krsmanović Marija

2016-01-01

Full Text Available The effects of field dodder on physiological processes and the anatomy of alfalfa plants were examined under controlled conditions. The experiment included the following variants: N - noninfested alfalfa plants (control; I - infested alfalfa plants (untreated; T - infested plants treated with imazethapyr. Imazethapyr application rate was 100 g a.i. ha-1. The following parameters were checked: physiological - pigment content (chlorophyll ɑ, chlorophyll b, total carotenoids; anatomical - stem parameters: thickness of epidermis and cortex, and diameter of stem and central cylinder; leaf parameters: thickness of epidermis, parenchyma and spongy tissue, mesophyll and underside leaf epidermis, and diameter of bundle sheath cells in alfalfa plants. Pigment contents and anatomical parameters were measured: prior to herbicide treatment (0 assessment, then 7 (I assessment, 14 (II assessment, 21 (III assessment, 28 (IV assessment and 35 (V assessment days after application (DAA. Field dodder was found to affect the contents of chlorophyll ɑ, chlorophyll ɑ and carotenoids in untreated alfalfa plants, causing significant reductions in pigment content. Conversely, percent reduction in the treated plants decreased 22-5% for chlorophyll ɑ, 25-1%, for chlorophyll b, and 21-11% for carotenoids, while a stimulating effect of 1-6% was observed for the contents of chlorophyll b and carotenoids 35 DAA. Plants infested (untreated by field dodder had lower values of most anatomical parameters, compared to noninfested plants. The measured anatomical parameters of alfalfa stems and leaves had significantly higher values in noninfested plants and plants treated with imazethapyr than in untreated plants.

Application of atmospheric plasma sources in growth and differentiation of plant and mammalian stem cells

Science.gov (United States)

Puac, Nevena

2014-10-01

The expansion of the plasma medicine and its demand for in-vivo treatments resulted in fast development of various plasma devices that operate at atmospheric pressure. These sources have to fulfill all demands for application on biological samples. One of the sources that meet all the requirements needed for treatment of biological material is plasma needle. Previously, we have used this device for sterilization of planctonic samples of bacteria, MRSA biofilm, for improved differentiation of human periodontal stem cells into osteogenic line and for treatment of plant meristematic cells. It is well known that plasma generates reactive oxygen species (ROS) and reactive nitrogen species (RNS) that strongly affect metabolism of living cells. One of the open issues is to correlate external plasma products (electrons, ions, RNS, ROS, photons, strong fields etc.) with the immediate internal response which triggers or induces effects in the living cell. For that purpose we have studied the kinetics of enzymes which are typical indicators of the identity of reactive species from the plasma created environment that can trigger signal transduction in the cell and ensue cell activity. In collaboration with Suzana Zivkovicm, Institute for Biological Research ``Sinisa Stankovic,'' University of Belgrade; Nenad Selakovic, Institute of Physics, University of Belgrade; Milica Milutinovic, Jelena Boljevic, Institute for Biological Research ``Sinisa Stankovic,'' University of Belgrade; and Gordana Malovic, Zoran Lj. Petrovic, Institute of Physics, University of Belgrade. Grants III41011, ON171037 and ON173024, MESTD, Serbia.

What is a stem cell?

Science.gov (United States)

Slack, Jonathan M W

2018-05-15

The historical roots of the stem cell concept are traced with respect to its usage in embryology and in hematology. The modern consensus definition of stem cells, comprising both pluripotent stem cells in culture and tissue-specific stem cells in vivo, is explained and explored. Methods for identifying stem cells are discussed with respect to cell surface markers, telomerase, label retention and transplantability, and properties of the stem cell niche are explored. The CreER method for identifying stem cells in vivo is explained, as is evidence in favor of a stochastic rather than an obligate asymmetric form of cell division. In conclusion, it is found that stem cells do not possess any unique and specific molecular markers; and stem cell behavior depends on the environment of the cell as well as the stem cell's intrinsic qualities. Furthermore, the stochastic mode of division implies that stem cell behavior is a property of a cell population not of an individual cell. In this sense, stem cells do not exist in isolation but only as a part of multicellular system. This article is categorized under: Adult Stem Cells, Tissue Renewal, and Regeneration > Tissue Stem Cells and Niches Adult Stem Cells, Tissue Renewal, and Regeneration > Methods and Principles Adult Stem Cells, Tissue Renewal, and Regeneration > Environmental Control of Stem Cells. © 2018 Wiley Periodicals, Inc.

Effects of plant conduction systems and organic fertilizer management on disease incidence and severity in ‘Osiana’ and ‘Carola’ roses

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Márcia de Nazaré Oliveira Ribeiro

2015-04-01

Full Text Available Conventional pruning is a very common practice for pruning rose cultivars in Brazil. However, few Brazilian producers known any other efficient plant training method for roses, namely “lateral stem bending” or “arching technique”, which involves bending the branches of the rosebush in order to increase the photosynthetic rate of the plant. As well as plant training, the use of fertilizers must also be done carefully in order to obtain high quality roses. Biofertilizers are recommended because of their multiple effects: fertilizer, protein synthesis stimulant, insect repellent, and disease controller. The aim of this study was to assess the plant training system and management of organic fertilizer on the incidence and severity of disease in the ‘Osiana’ and ‘Carola’ roses. The ‘Osiana’ rosebushes received three concentrations (0%, 5%, and 15% of foliar biofertilizer applied monthly to the leaves together with two plant conduction methods (conventional pruning and lateral stem bending. ‘Carola’ roses were treated with three types of fertilizer (chemical fertilizer on the soil + bokashi on the soil, chemical fertilizer on the soil + foliar FishfertilÒand chemical fertilization on the soil without applying organic fertilizers every two weeks, together with 2 plant conduction systems (conventional pruning and lateral stem bending. The additional treatments in ‘Carola’ roses were composed of two organic fertilizers (Bokashi and foliar Fishfertil® and chemical fertilization with lateral pruning. The incidence and severity of disease in these plants during the experiment were assessed over 5 months. For the ‘Osiana’ rose, the incidence and severity of disease were not influenced by fertilizer management or plant training methods. For the ‘Carola’ roses, the different types of fertilizer caused different responses according to the plant training system used, with the biofertilizer Fishfertil® reducing the incidence

Obtention of Vasconcellea x helbornii (Badillo Badillo mother plants from cuttings under semi-controlled conditions

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Mónica Jadán Guerrero

2016-01-01

Full Text Available The babaco [Vasconcellea x helbornii (Badillo Badillo] also known as mountain papaya is a native fruit from the highlands of Ecuador and Colombia. The present work was carried out with the objective of establishing a bank of donor plants of the babaco hybrid from cuttings, under semicontrolled conditions. Two-year-old plants grown in greenhouse was used as initial plant material. Subsequently, the stem was divided into different sections of 25 cm in length. These were planted in plastic sheaths with substrate and subjected to a phytosanitary control with 0.5% (v / v Carbendazim fungicide. At six weeks of culture, the number of rooted cuttings, the number and length of shoots and number of leaves per cutting were quantified. The effect of biostimulant application (GERMO-TB01 was also determined to increase the number of axillary shoots. The results of this work allowed to reach a 100% budding and root formation in the different sections of stem. The best results in the formation of new shoots were reached in explants S1, S2 and S3. However, when applying the biostimulant the formation of new shoots increased to 5.82 per stem sections with better quality. Since the results of this work will be available donor plant material to develop in vitro propagation protocols of this hybrid, with high genetic and phytosanitary quality.   Key word: bio-stimulant, donor plant material, greenhouse, rooting

Chemical constituents in n-butanol fractions of Costus afer ker Gawl leaf and stem

Directory of Open Access Journals (Sweden)

Godswill Nduka Anyasor

2014-04-01

Conclusion: The bioactive compounds identified in the n-butanol fractions of C. afer leaves and stem may explain the folkloric use of C. afer plant in the treatment of chronic inflammatory and oxidative stress related diseases. [J Intercult Ethnopharmacol 2014; 3(2.000: 78-84

Bacterial diversity of oil palm Elaeis guineensis basal stems

Science.gov (United States)

Amran, Afzufira; Jangi, Mohd Sanusi; Aqma, Wan Syaidatul; Yusof, Nurul Yuziana Mohd; Bakar, Mohd Faizal Abu; Isa, Mohd Noor Mat

2016-11-01

Oil palm, Elaeis guineensis is one of the major industrial production crops in Malaysia. Basal stem rot, caused by the white fungus, Ganoderma boninense, is a disease that reduces oil palm yields in most production areas of the world. Understanding of bacterial community that is associated with Ganoderma infection will shed light on how this bacterial community contributes toward the severity of the infection. In this preliminary study, we assessed the bacterial community that inhabit the basal stems of E. guineensis based on 16S rRNA gene as a marker using next generation sequencing platform. This result showed that a total of 84,372 operational taxonomic-units (OTUs) were identified within six samples analyzed. A total 55,049 OTUs were assigned to known taxonomy whereas 29,323 were unassigned. Cyanobacteria, Bacteroidetes, Firmicutes and Proteobacteria were the most abundant phyla found in all six samples and the unique taxonomy assigned for each infected and healthy samples were also identified. The findings from this study will further enhance our knowledge in the interaction of bacterial communities against Ganoderma infection within the oil palm host plant and for a better management of the basal stems rot disease.

Establishment and in-house validation of stem-loop RT PCR method for MicroRNA398 expression analysis

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Timotijević Gordana S.

2015-01-01

Full Text Available MicroRNAs (miRNAs belong to the class of small non-coding RNAs which have important roles throughout development as well as in plant response to diverse environmental stresses. Some of plant miRNAs are essential for regulation and maintenance of nutritive homeostasis when nutrients are in excess or shortage comparing to optimal concentration for certain plant species. Better understanding of miRNAs functions implies development of efficient technology for profiling their gene expression. We set out to establish validate the methodology for miRNA gene expression analysis in cucumber grown under suboptimal mineral nutrient regimes, including iron deficiency. Reverse transcription by “stem-loop” primers in combination with Real time PCR method is one of potential approaches for quantification of miRNA gene expression. In this paper we presented a method for “stem loop” primer design specific for miR398, as well as reaction optimization and determination of Real time PCR efficiency. Proving the accuracy of this method was imperative as “stem loop” RT which consider separate transcription of target and endogenous control. The method was verified by comparison of the obtained data with results of miR398 expression achieved using a commercial kit based on simultaneous conversion of all RNAs in cDNAs. [Projekat Ministarstva nauke Republike Srbije, br. 173005 i br. ON-173028

Phytoplasmal infection derails genetically preprogrammed meristem fate and alters plant architecture

OpenAIRE

Wei, Wei; Davis, Robert Edward; Nuss, Donald L.; Zhao, Yan

2013-01-01

In higher plants, the destiny of apical meristems (stem cells) is specific organogenesis, which determines the pattern of plant growth, and therefore morphotype and fertility. We found that bacterial infection can derail the meristems from their genetically preprogrammed destiny, altering plant morphogenesis. We identified four abnormal growth patterns, symptoms, in tomato infected with a cell wall-less bacterium, and found that each symptom corresponds to a distinct phase in meristem fate de...

Advancing Stem Cell Biology toward Stem Cell Therapeutics

OpenAIRE

Scadden, David; Srivastava, Alok

2012-01-01

Here, the International Society for Stem Cell Research (ISSCR) Clinical Translation Committee introduces a series of articles outlining the current status, opportunities, and challenges surrounding the clinical translation of stem cell therapeutics for specific medical conditions.

Effects of amendments on the uptake and distribution of DDT in Cucurbita pepo ssp pepo plants

International Nuclear Information System (INIS)

Whitfield Aslund, Melissa L.; Lunney, Alissa I.; Rutter, Allison; Zeeb, Barbara A.

2010-01-01

The effects of soil amendments on the phytoextraction of ΣDDT (DDT + DDD + DDE) from soil ([ΣDDT] ∼ 1500 ng/g) by a pumpkin variety of Cucurbita pepo ssp pepo were tested and the patterns of ΣDDT storage throughout the plant shoot were examined. The soil amendments did not increase the total amount of ΣDDT extracted into plant shoots, but new information about ΣDDT distribution in the plants was obtained. As observed previously, the ΣDDT concentration in plant leaves (mean 290 ng/g) was significantly lower than in plant stems (mean 2600 ng/g). Further analysis revealed that ΣDDT composition was consistent throughout the plant shoot and that ΣDDT concentration in leaves and stems decreased exponentially as distance from the root increased, which was previously unknown. This new information about the patterns of ΣDDT uptake and translocation within pumpkin plants highlights the need for appropriate plant sampling strategies in future POPs phytoextraction research. - Patterns of ΣDDT storage in a pumpkin plant are elucidated and specific surfactant and mycorrhizal soil amendments did not increase the total amount of ΣDDT phytoextracted into plant shoots.

STEM crisis or STEM surplus? Yes and yes.

Science.gov (United States)

Xue, Yi; Larson, Richard C

2015-05-01

The last decade has seen considerable concern regarding a shortage of science, technology, engineering, and mathematics (STEM) workers to meet the demands of the labor market. At the same time, many experts have presented evidence of a STEM worker surplus. A comprehensive literature review, in conjunction with employment statistics, newspaper articles, and our own interviews with company recruiters, reveals a significant heterogeneity in the STEM labor market: the academic sector is generally oversupplied, while the government sector and private industry have shortages in specific areas.

Variation in chemical components and biological activity of Pterocarya fraxinifolia Lam. stems at different developmental stages

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M. Akhbari

2017-07-01

Full Text Available Background and objectives: Pterocarya fraxinifolia Lam. is a deciduous, fast-growing tree from walnut family. The stem barks and fruits of the plant have been used as diaphoretic in traditional medicine. Variation in the quantity and quality of the essential oil and extract of stems of the plant at different developmental stages was evaluated in addition to assessing the antimicrobial, cytotoxic and radical scavenging activities in the present study. Methods: Different developmental stages of the plant’s stem (i.e. vegetative, flowering, immature fruit and mature fruit were subjected to hydro-distillation for obtaining the essential oil. The methanol extract of the samples was obtained by Soxhlet apparatus. Chemical composition of the oils was analyzed by gas chromatography/mass spectroscopy (GC/MS. Antimicrobial activity of the oils and extracts were determined against three Gram-positive and five Gram-negative bacteria and two fungi by disc diffusion method. Antioxidant activity of the samples was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH and β-carotene assays. Total phenolics content of extracts was determined using Folin-Ciocalteau reagent and cytotoxic effect was determined by brine shrimp lethality bioassay. Results: Hexadecanoic acid was one of the major components in all essential oil samples. All samples showed good antimicrobial activity against tested strains. Antioxidant activity of the extracts was comparable to the synthetic standard (butylated hydroxytoluene. The highest total phenolic content and cytotoxic effect were detected for the mature fruit stage of the plant extract and essential oil, respectively. Conclusion: Showing considerable antioxidant and cytotoxic effects, suggested the plant as a good candidate for further investigations.

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

International Nuclear Information System (INIS)

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

2012-01-01

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.

Historical versus contemporary medicinal plant uses in Ghana

DEFF Research Database (Denmark)

Soelberg, Jens; Asase, A; Akwetey, G

2015-01-01

among contemporary medicinal plant uses in Ghana and represent some of the most important Ghanaian medicinal plant species. However, 93 (69%) of the historical uses could not be traced and appears to be discontinued or forgotten. Among the Ga, two medicinal plants species have become rare or locally......ETHNOPHARMACOLOGICAL RELEVANCE: Three extraordinary, historical documents stemming from observations made in 1697, 1803 and 1817 quote medicinal plant uses among the Fante, Ga and Ashanti people of present-day Ghana, and can be linked to original botanical specimens in European herbaria....... This provides a unique opportunity to gain insight to the historical materia medica of Ghana and compare this to contemporary medicinal plant uses. By critical literary and taxonomic review, the present study (re-)establishes the earliest known history of many important Ghanaian medicinal plants, and assesses...

Multitracer study on absorption of radionuclides in atmosphere-plant system

International Nuclear Information System (INIS)

Ambe, Shizuko; Shinonaga, Taeko; Watanabe, Tadakazu; Yamaguchi, Isamu

1996-01-01

Direct absorption of atmospheric radionuclides by soybean plants was studied using a radioactive multitracer consisting of radionuclides of Sc, Mn, Co, As, Se, Rb, Sr, Y, Eu, Gd, Yb, Hf, Re, and Ir. Soybean seedlings were cultivated at 23degC in a box where multitracer-adsorbed cellulose powders were floating in air. After 28-49 day-cultivation, the plants were harvested and divided into beans (seeds and pods), leaves, stems (inside and outside), and roots. Beans or leaves originating from the same node were collected together. After washing with dilute HCl solution and distilled water, they were dried and then subjected to γ-ray measurement. It was estimated that about 0.2 % of the multitracer was absorbed by the soybean plant, of which 80 % was found in the leaves, and 10 % each in beans and stems. The relative amounts of elements in the beans, leaves, and stems markedly differed depending on the element. Among the elements, Se * was greatly accumulated in the beans, leaves, and stems. Cobalt * , Se * , and Rb * were dominant in the beans, especially in the edible part of seeds. Relative amounts of Mn * , As * , Sr * , and Re * in the seeds were very small. It is noticeable that these nuclides were found in the seeds, though they were not physically exposed to the multitracer-adsorbed cellulose powders during growth. The radioactivities of Sc * , Mn * , Co * , As * , Se * , Rb * , Sr * , Y * , Eu * , Gd * , Yb * , Hf * , Re * , and Ir * were observed for the leaves. Brown leaves accumulated greater amounts of radionuclides than green ones. Main nuclides found in the stem were Sc * , Co * , Se * , Y * , Eu * , Gd * , Yb * , Hf * , and Ir * , a larger part of them on the outside. Trace amounts of Co * , Se * , and Rb * were detected in the roots. Little leakage of the multitracer into the soil was observed. These results indicate that various radionuclides in the atmosphere were directly absorbed through soybean leaves and then transported to the edible part

The Species Richness of Vascular Plants and Amphibia in Major Plant Communities in Temperate to Tropical Australia: Relationship with Annual Biomass Production

International Nuclear Information System (INIS)

Specht, R. L.; Tyler, M.J.

2010-01-01

Aerodynamic fluxes (frictional, thermal, evaporative) in the atmosphere as it flows over and through a plant community determine the Foliage Projective Covers and eco-morphological attributes of new leaves developed annually in overstorey and understorey strata. The number of leaves produced on vertical foliage shoots depends on available soil water and nutrients, also ambient temperature, during this short growth season. Stem density (number of stems per hectare) and species richness (number of species per hectare) in the overstorey of major Floristic Groups are correlated with annual shoot growth (ASG, t ha-1) in that stratum. Species richness in the overstorey increases in the climatic gradient from the arid to the humid zone as well as with increasing air temperatures (about 10 degree C) from temperate to tropical Australia. Species richness in the understorey is highest in plant communities in temperate Australia, decreasing in the temperature gradient towards the tropics. As with other major plant and animal groups within an ecosystem, the species richness of Amphibia is correlated with the amount of solar energy fixed (per annum) by the major plant formation in the regional photosynthetic potential determined by the foliage shoots (ASG, t ha-1) produced annually in the overstorey.

The Species Richness of Vascular Plants and Amphibia in Major Plant Communities in Temperate to Tropical Australia: Relationship with Annual Biomass Production

Directory of Open Access Journals (Sweden)

R. L. Specht

2010-01-01

Full Text Available Aerodynamic fluxes (frictional, thermal, evaporative in the atmosphere as it flows over and through a plant community determine the Foliage Projective Covers and eco-morphological attributes of new leaves developed annually in overstorey and understorey strata. The number of leaves produced on vertical foliage shoots depends on available soil water and nutrients, also ambient temperature, during this short growth season. Stem density (number of stems per hectare and species richness (number of species per hectare in the overstorey of major Floristic Groups are correlated with annual shoot growth (ASG, t ha−1 in that stratum. Species richness in the overstorey increases in the climatic gradient from the arid to the humid zone as well as with increasing air temperatures (about 10oC from temperate to tropical Australia. Species richness in the understorey is highest in plant communities in temperate Australia, decreasing in the temperature gradient towards the tropics. As with other major plant and animal groups within an ecosystem, the species richness of Amphibia is correlated with the amount of solar energy fixed (per annum by the major plant formation in the region—a photosynthetic potential determined by the foliage shoots (ASG, t ha−1 produced annually in the overstorey.

Phytoextraction of rare earth elements in herbaceous plant species growing close to roads.

Science.gov (United States)

Mikołajczak, Patrycja; Borowiak, Klaudia; Niedzielski, Przemysław

2017-06-01

The aim of study was to determine the phytoextraction of rare earth elements (REEs) to roots, stems and leaves of five herbaceous plant species (Achillea millefolium L., Artemisia vulgaris L., Papaver rhoeas L., Taraxacum officinale AND Tripleurospermum inodorum), growing in four areas located in close proximity to a road with varied traffic intensity. Additionally, the relationship between road traffic intensity, REE concentration in soil and the content of these elements in plant organs was estimated. A. vulgaris and P. rhoeas were able to effectively transport REEs in their leaves, independently of area collection. The highest content of REEs was observed in P. rhoeas leaves and T. inodorum roots. Generally, HREEs were accumulated in P. rhoeas roots and leaves and also in the stems of T. inodorum and T. officinale, whereas LREEs were accumulated in T. inodorum roots and T. officinale stems. It is worth underlining that there was a clear relationship between road traffic intensity and REE, HREE and LREE concentration in soil. No positive correlation was found between the concentration of these elements in soil and their content in plants, with the exception of T. officinale. An effective transport of REEs from the root system to leaves was observed, what points to the possible ability of some of the tested plant species to remove REEs from soils near roads.

Transgenic potato plants expressing cry3A gene confer resistance to Colorado potato beetle.

Science.gov (United States)

Mi, Xiaoxiao; Ji, Xiangzhuo; Yang, Jiangwei; Liang, Lina; Si, Huaijun; Wu, Jiahe; Zhang, Ning; Wang, Di

2015-07-01

The Colorado potato beetle (Leptinotarsa decemlineata Say, CPB) is a fatal pest, which is a quarantine pest in China. The CPB has now invaded the Xinjiang Uygur Autonomous Region and is constantly spreading eastward in China. In this study, we developed transgenic potato plants expressing cry3A gene. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis indicated that the cry3A gene expressed in leaves, stems and roots of the transgenic plants under the control of CaMV 35S promoter, while they expressed only in leaves and stems under the control of potato leaf and stem-specific promoter ST-LS1. The mortality of the larvae was higher (28% and 36%) on the transgenic plant line 35S1 on the 3rd and 4th days, and on ST3 (48%) on the 5th day after inoculation with instar larvae. Insect biomass accumulation on the foliage of the transgenic plant lines 35S1, 35S2 and ST3 was significantly lower (0.42%, 0.43% and 0.42%). Foliage consumption was lowest on transgenic lines 35S8 and ST2 among all plant foliage (7.47 mg/larvae/day and 12.46 mg/larvae/day). The different transgenic plant foliages had varied inhibition to larval growth. The survivors on the transgenic lines obviously were smaller than their original size and extremely weak. The transgenic potato plants with CPB resistance could be used to develop germplasms or varieties for controlling CPB damage and halting its spread in China. Copyright © 2015 Académie des sciences. Published by Elsevier SAS. All rights reserved.

A study on the stem friction coefficient with differential pressure conditions for the motor operated flexible wedge gate valve

International Nuclear Information System (INIS)

Kim, Dae Woong; Park, Sung Keun; Kim, Yang Seok; Lee, Do Hwan

2008-01-01

Stem friction coefficient is very important parameter for the evaluation of valve performance. In this study, the characteristics of stem friction coefficient is analyzed, and the bounding value is determined. The hydraulic testing is performed for flexible wedge gate valves in the plant and statistical method is applied to the determination of bounding value. According to the results of this study, stem friction coefficient is not effected in low differential pressure condition, but it is showed different distribution in medium and high differential pressure condition. And the bounding value of closing stroke is higher than that of opening stroke

Effect of Plant Density, Rate and Split Application of Nitrogen Fertilizer on Quality Characteristics and Nitrogen Use Efficiency of Safflower under Weed Competition

Directory of Open Access Journals (Sweden)

M Fuladvand

2015-09-01

Full Text Available In order to evaluation of plant density, rate and method of nitrogen fertilizer split application on quality characteristics and nitrogen use efficiency of safflower (Sofeh variety under weed competition a field experiment was carried out in field research Yasouj University in 2013. This experiment was a factorial based on randomized complete block design with three replications. First factor was a two levels plant density (20 and 40 plants m-2 and second factor was nitrogen rate application on nine levels. That included; non nitrogen application and 75 and 150 kgN ha-1 nitrogen application that both used with four split method. Split methods were included; S1 (%50 in pre planting stage - %50 in stem elongation stage, S2 (%25 in pre planting stage - %75 in stem elongation stage, S3 (%25 in pre planting stage - %50 in stem elongation stage -%25 in flowering stage and S4 (%25 in pre planting stage - %25 in stem elongation stage - %25 in flowering stage. Also in this experiment, weed did not control. Results showed that whit increasing crop density, oil yield and protein grain yield increased by 20 percent and nitrogen utilization efficiency increased by 10 percent. The highest oil yield (50.25 g m-2 was obtained from 75 kg ha-1 nitrogen with three-stage split application (S4. Finally, results showed that increasing nitrogen fertilizer application decreased nitrogen utilization efficiency but three-stage split method application increased this trait.

Application of Trichoderma harzianum in the control of basal stem rot of oil palms

Institute of Scientific and Technical Information of China (English)

Abdullah F; Ilias G N M

2004-01-01

@@ The palm, Elaeis guineensis, has its origins in Africa but is planted on a commercial basis in several countries Statistics for 2002 showed that in the lead for land mass under oil palm cultivation is Indonesia, at 3,769,000 ha, followed by Malaysia at 3,376,000 ha; however, the world' s leading producer of palm oil is still Malaysia, since the 1970's. Both countries are predicted to produce 82.4%of the world's palm oil production by the year 2005. However, the palm is susceptible to basal stem rot, a devastating disease which results in direct loss of field stands and to which no effective chemical control is yet available. Caused by Ganoderma boninense, infected palms appear symptomless, at the first sign of disease, at least 50 % of the internal trunk tissue stem would have actually rotted. This study investigated the efficacy of Trichoderma harzianum (isolate FA 1132) as a biological control agent, using 6-month old oil palm seedlings as models and the experiment performed in a greenhouse at 29-30 ℃ ambient conditions. The plants were artificially infected with G. boninense and a conidial suspension of 1 × 109-9 × 109 spores/mL was applied as a soil drench at 1L/plant every 2 weeks for 20weeks. The parameters examined were efficacy of the biocontrol agent and the effect of Trichodermaincorporated mulch in addition to the soil drench. Efficacy was assessed in terms disease severity index (DSI) where a higher percentage indicates a higher severity. Results showed that infection first sets in on untreated plants at week 12 and got worse progressively. The completely untreated plants were all infected and the DSI at 20 weeks after infection (wa. i.) was 92. 5%. Plants given only a Trichoderma -infused food base supplement without conidial suspension gave a DSI of 70% whereas those given a conidial soil drench without supplemental food base gave a DSI of 85% at 20 w.a.i.Infected plants given a conidial treatment together with a food base supplement gave a DSI

Public-Private Partnerships in Plant Genomics for Global Food

International Development Research Centre (IDRC) Digital Library (Canada)

Ina

2012-06-06

Jun 6, 2012 ... revolution in the way we approach the science of crop im- provement. ... to transition its emphasis from generation of sequence data ...... genetic markers for Ug99 stem rust. 2009- ..... Plant Cell Physiology 52(12): 2017-2038.

Screening of endophytic plant growth-promoting bacteria isolated ...

African Journals Online (AJOL)

Probiotic bacteria, inhabiting the endosphere of plants, presents a major opportunity to develop cheap and eco-friendly alternatives to synthetic agrochemicals. Using standard microbiological procedures, culturable bacteria were isolated from the endosphere (root, stem and leaf) of two Nigerian rice varieties (Ofada and ITA ...

Activity of Oligoresveratrols from Stem Bark of Hopea mengarawan (Dipterocarpaceae as Hydroxyl Radical Scavenger

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SRI ATUN

2006-06-01

Full Text Available Four oligoresveratrols ranging from dimer to tetramer, isolated from stem bark of Hopea mengarawan (Dipterocarpaceae plants were tested for their activity as hydroxyl radical scavenger. The activity of these compounds was evaluated against the 2-deoxyribose degradation induced by the hydroxyl radical generated via a Fenton-type reaction. Result showed that balanocarpol, heimiol A, vaticanol G, and vaticanol B had IC50 3.83; 15.44; 2.01; and 4.71 µM, respectively. These results suggest that oligoresveratrols from stem bark of H. mengarawan maybe useful as potential sources of natural antioxidants.

Natural Hypolignification Is Associated with Extensive Oligolignol Accumulation in Flax Stems1[C][W

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Huis, Rudy; Morreel, Kris; Fliniaux, Ophélie; Lucau-Danila, Anca; Fénart, Stéphane; Grec, Sébastien; Neutelings, Godfrey; Chabbert, Brigitte; Mesnard, François; Boerjan, Wout; Hawkins, Simon

2012-01-01

Flax (Linum usitatissimum) stems contain cells showing contrasting cell wall structure: lignified in inner stem xylem tissue and hypolignified in outer stem bast fibers. We hypothesized that stem hypolignification should be associated with extensive phenolic accumulation and used metabolomics and transcriptomics to characterize these two tissues. 1H nuclear magnetic resonance clearly distinguished inner and outer stem tissues and identified different primary and secondary metabolites, including coniferin and p-coumaryl alcohol glucoside. Ultrahigh-performance liquid chromatography-Fourier transform ion cyclotron resonance-mass spectrometry aromatic profiling (lignomics) identified 81 phenolic compounds, of which 65 were identified, to our knowledge, for the first time in flax and 11 for the first time in higher plants. Both aglycone forms and glycosides of monolignols, lignin oligomers, and (neo)lignans were identified in both inner and outer stem tissues, with a preponderance of glycosides in the hypolignified outer stem, indicating the existence of a complex monolignol metabolism. The presence of coniferin-containing secondary metabolites suggested that coniferyl alcohol, in addition to being used in lignin and (neo)lignan formation, was also utilized in a third, partially uncharacterized metabolic pathway. Hypolignification of bast fibers in outer stem tissues was correlated with the low transcript abundance of monolignol biosynthetic genes, laccase genes, and certain peroxidase genes, suggesting that flax hypolignification is transcriptionally regulated. Transcripts of the key lignan genes Pinoresinol-Lariciresinol Reductase and Phenylcoumaran Benzylic Ether Reductase were also highly abundant in flax inner stem tissues. Expression profiling allowed the identification of NAC (NAM, ATAF1/2, CUC2) and MYB transcription factors that are likely involved in regulating both monolignol production and polymerization as well as (neo)lignan production. PMID:22331411

Antioxidant, anti-inflammatory and antiproliferative activities of Kalanchoe gracilis (L.) DC stem.

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Lai, Zhen-Rung; Ho, Yu-Ling; Huang, Shun-Chieh; Huang, Tai-Hung; Lai, Shang-Chih; Tsai, Jen-Chieh; Wang, Ching-Ying; Huang, Guan-Jhong; Chang, Yuan-Shiun

2011-01-01

Oxidative stress and inflammation are related to several chronic diseases including cancer and atherosclerosis. Kalanchoe gracilis (L.) DC is a special folk medicinal plant in Taiwan. The aim of this study was to evaluate the antioxidant, anti-inflammatory and antiproliferative activities of the methanolic extract and fractions of the stem of K. gracilis. TEAC, total phenolic compound content, total flavonoid content, DPPH radical scavenging activity, reducing power, inhibition of NO production in LPS-induced RAW264.7 cells, and inhibition of cancer cell proliferation were analyzed. Among all fractions, the chloroform fraction showed the highest TEAC and DPPH radical scavenging activities. The chloroform fraction also had the highest content of polyphenols and flavonoids. Chloroform fractions also decreased LPS-induced NO production and expressions of iNOS and COX-2 in RAW264.7 cells. The antiproliferative activities of the methanolic extract and fractions were studied in vitro using HepG2 cells, and the results were consistent with their antioxidant capacities. Chloroform fractions had the highest antiproliferative activity with an IC(50) of 136.85 ± 2.32 μg/ml. Eupafolin also had good pharmacological activity in the antioxidant, anti-inflammation and antiproliferative. Eupafolin might be an important bioactive compound in the stem of K. gracilis. The above experimental data indicated that the stem of K. gracilis is a potent antioxidant medicinal plant, and such efficacy may be mainly attributed to its polyphenolic compounds.

Determination of plant species for the phytoremediation of carbofuran residue in rice field soils

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Alissara Reungsang

2005-09-01

Full Text Available This study searched for plant species suitable for accumulating carbofuran residue in rice field soil. Three groups of plant, i.e. grass crops, upland crops, and vegetable crops, were grown in 8 inches diameter plastic pots filled with soil containing 5 mg/kg carbofuran. Parts of plants (stems and leaves, roots, fruits were harvested at day 120 and analyzed for carbofuran residue using HPLC. The results indicated that Helianthus annuus L. (sunflower was the most suitable species for phytoremediation of carbofuran residue in rice field soil because it highly accumulated carbofuran up to 93.4 μg/kg dry weight in its stems and leaves. In addition, H. annuus L. (sunflower could tolerate carbofuran since it showed similar physical appearance (circumference and height to control not receiving carbofuran.

[Autotoxicity of aqueous extracts from plant of cultivated Astragalus membranaceus var. mongholicus].

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Zhang, Xin-Hui; Lang, Duo-Yong; Chen, Jing; Zhao, Yun-Sheng; Wu, Xiu-Li; Fu, Xue-Yan

2014-02-01

To exploring the relationship between continuous cropping obstacle and autotoxicity of Astragalus membranaceus var. mongholicus, autotoxic effect of plant aqueous extract were determined. Distilled water (CK), aqueous extract of plant, including root, stem and leaf (12.5, 25, 50 and 100 mg/mL respectively)were applied to testing their effect on early growth of Astragalus membranaceus var. mongholicus. Specifically, seed germination rate, germination index, emergence rate, elongation of radical and embryo, and seedling vigor index were determined. The aqueous extract of root, stem, and leaf at 25 mg/mL significantly inhibited the seed germination and seedling growth of Astragalus membranaceus var. mongholicus, and this inhibitory effect generally increased with the increase of the concentration of aqueous extracts. To the comprehensive allelopathic effect, the extracts from Astragalus membranaceus var. mongholicus stem were more inhibitory than those from leaf and root. The germination index and seedling vigor index were more sensitive to extract than other determined parameters. Aqueous extracts from Astragalus membranaceus var. mongholicus plant gave inhibitory effects on Astragalus. membranaceus var. mongholicus germination and seedling growth, and this inhibitory effect generally increased with the increases of aqueous extract concentration at a certain ranges. In conclusion, there is an autotoxicity in continuous cropping of Astragalus membranaceus var. mongholicus.

Antioxidant activity and concentration of secondary metabolites in the plant parts of Euphorbia cyparissias L.

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Stanković Milan S.

2014-01-01

Full Text Available This paper presents the results of a screening of nine different extracts from the plant parts (leaves, flowers and stems of Euphorbia cyparissias for total phenolic content, concentration of flavonoids and in vitro antioxidant activity. Main reason for this study is the determination of these parameters and their variability among plant parts and plant extracts obtained by different solvents, respectively. Obtained amounts for total phenolic content ranged from 10.76 to 40.72 mg GA/g. The concentration of flavonoids varied from 34.32 to 134.34 mg Ru/g. The IC50 values of antioxidant activity varied from 88.48 to 2891.08 μg/ml. Results obtained from the different plant parts were of uneven value. Great variability of the studied parameters was observed when comparing the effectiveness of the used solvents. The acetone extracts from stems contain the greatest concentrations of phenolic compounds, especially flavonoids, and showed high antioxidant activity. According to our research, plant parts from E. cyparissias can be regarded as promising candidates for natural plant sources with high value of biological compounds.

Allelopathic Effects of Aqueous Extract of Leaf Stem and Root of Sorghum bicolor on Seed Germination and Seedling Growth of Vigna radiata L.

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Amir MOOSAVI

2011-05-01

Full Text Available Seed germination under field conditions is highly influenced by the presence of other plants. Allelopathy is an important mechanism of plant competition, by producing phytotoxins to the plant environment in order to decline other plants� growth. Soil sickness problem in farm lands is also known as an allelopathic effect or even autotoxicity. The toxicity of released allelochemicals by a plant in the environment is attributed to its function of concentration, age and metabolic stage. In this study we investigate the effect (5, 20, 35 and 50 g l-1 of leaf, stem and root water extract of sorghum on seed germination and seedling growth of mung bean. The results of the experiment showed that allelopathic effect of different concentrations was not significant for germination percentage, but germination rate and mean germination time decreased significantly by increasing the concentration of allelopathic extracts; also, there was a clear allelopathic effect of sorghum extract on seedling growth of mung bean. 50 g l-1 sorghum stem extract exhibited the highest inhibitory effect on root and shoot growth of mung bean. Among all parts of sorghum, stem extracts showed the highest allelopatic effect on seedling growth. Root extract showed higher inhibitory effect than leaf extracts.

Cellular therapy without cells: extracellular vesicles promote activation of stem cells after irradiation

International Nuclear Information System (INIS)

Lange, C.

2016-01-01

Mesenchymal stromal cells from the bone marrow (MSC) have been shown to be effective in several cell therapeutic treatments. However, MSC accumulate in lungs after i.v. injection. How do MSC transfer their potential to organs with therapeutic need? We show that released extracellular vesicles (EV) might be playing an active role in this transfer. EV were isolated from MSC supernatant and characterized with flow cytometry, proteomics and next generation sequencing. Our data showed the transfer of RNAs, clustering into several protective gene groups. Besides, we repeatedly detected genomic DNA on vesicles. Using a plant - derived detector gene we showed horizontal DNA transfer via EV. Furthermore, we showed that EV were able to salvage stem/progenitor cells in vitro from radiation suppression. Three selected proteins from proteomics data were examined for stem cell protection after irradiation. EV derived from down-regulated producer MSC showed a substantial loss of protection in irradiated stem cells supporting their relevance for stem cell protection. Finally, we showed that EV after i.v. injection into lethally irradiated animals colocalize within 2-4 hours with hematopoietic stem cells in the bone marrow giving hint to direct protection of stem cells by EV. In conclusion, EV derived from bone marrow MSC were able to transfer several cargo compounds leading potentially to change of the genetic properties. Importantly, EV protect irradiated hematopoietic stem cells, stimulate their recovery and proliferation and rescue lethally irradiated animals long-term. Thus, EV might be an alternative for future cell therapeutic treatment particularly in radiation-based events. (author)

The Development of the STEM Career Interest Survey (STEM-CIS)

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Kier, Meredith W.; Blanchard, Margaret R.; Osborne, Jason W.; Albert, Jennifer L.

2014-06-01

Internationally, efforts to increase student interest in science, technology, engineering, and mathematics (STEM) careers have been on the rise. It is often the goal of such efforts that increased interest in STEM careers should stimulate economic growth and enhance innovation. Scientific and educational organizations recommend that efforts to interest students in STEM majors and careers begin at the middle school level, a time when students are developing their own interests and recognizing their academic strengths. These factors have led scholars to call for instruments that effectively measure interest in STEM classes and careers, particularly for middle school students. In response, we leveraged the social cognitive career theory to develop a survey with subscales in science, technology, engineering, and mathematics. In this manuscript, we detail the six stages of development of the STEM Career Interest Survey. To investigate the instrument's reliability and psychometric properties, we administered this 44-item survey to over 1,000 middle school students (grades 6-8) who primarily were in rural, high-poverty districts in the southeastern USA. Confirmatory factor analyses indicate that the STEM-CIS is a strong, single factor instrument and also has four strong, discipline-specific subscales, which allow for the science, technology, engineering, and mathematics subscales to be administered separately or in combination. This instrument should prove helpful in research, evaluation, and professional development to measure STEM career interest in secondary level students.

Investigation on anatomical, chemical and pulping characteristics of Silybum marianum stem

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Rahim Yadollahi

2013-11-01

Full Text Available To study the possibility of using plant Silybum marianum in paper industry, its stem yield potential, chemical properties, fiber indices and pulping was evaluated. Mean value of fiber length and diameter of Silybum marianumstem harvested in early June, were calculated 178 and 3.5 cm, respectively. Dry weight of whole stem determined 4710 kg per hectar. Mean value of fiber length, diameter, cavity diameter and wall thickness were obtained 1194, 16.06, 9.06, and 3.66 μm, respectively. Raunkel, flexibility, and slenderness ratios of its fibers were determined 80.83, 56.39, and 74.37, respectively. Results of chemical analysis showed that the stem comprises %70.35 holocellulose, %39.25 cellulose, %13.13 lignin, %3.09 acetone-soluble, %18 hot water-soluble extractives, and %11/85 ash. Soda pulp was obtained at 165 °C pulping time, 25% alkaline and 10:1 ratio of liquor to chips. Results of pulping showed that with increasing of pulping time from 30 to 210 minutes, the kappa number and yield decreased from 77.32 to 32.13 and 43.6 to 36.5, respectively; whereas accepted pulp yield (passed from 20 mesh increased from 17.4 to 35.5% paper made of pulp with kappa number 32 had 36.82 Nm/g tensile index, 3.76 km breaking length and 1.75 Kpa.m2/g burst strength. In general, achieved results have shown that the present studied species could be regarded more for papermaking because of the suitable fiber biometrical and chemical properties as compared to other non-woody plants.

An Informal Science Education Program's Impact on STEM Major and STEM Career Outcomes

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Habig, Bobby; Gupta, Preeti; Levine, Brian; Adams, Jennifer

2018-04-01

While there is extensive evidence that STEM careers can be important pathways for augmenting social mobility and for increasing individual prestige, many youth perceive a STEM trajectory as an unattractive option. In the USA, women and members of historically marginalized racial and ethnic groups continue to be underrepresented across STEM disciplines. One vehicle for generating and sustaining interest in STEM is providing youth long-term access to informal science education (ISE) institutions. Here, we incorporate triangulation methods, collecting and synthesizing both qualitative and quantitative data, to examine how participation in a longitudinal ISE out-of-school time (OST) program facilitated by the American Museum of Natural History (AMNH) impacted the STEM trajectories of 66 alumni. Findings revealed that 83.2% of alumni engaged in a STEM major, and 63.1% in a STEM career, the majority whom were females and/or members of historically underrepresented racial and ethnic groups. Based on interviews with a purposeful sample of 21 AMNH alumni, we identified four program design principles that contributed to persistence in STEM: (1) affording multiple opportunities to become practitioners of science; (2) providing exposure to and repeated experiences with STEM professionals such as scientists, educators, and graduate students to build social networks; (3) furnishing opportunities for participants to develop shared science identities with like-minded individuals; and (4) offering exposure to and preparation for a variety of STEM majors and STEM careers so that youth can engage in discovering possible selves. These findings support our central thesis that long-term engagement in ISE OST programs fosters persistence in STEM.

Whole-plant allocation to storage and defense in juveniles of related evergreen and deciduous shrub species.

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Wyka, T P; Karolewski, P; Żytkowiak, R; Chmielarz, P; Oleksyn, J

2016-05-01

In evergreen plants, old leaves may contribute photosynthate to initiation of shoot growth in the spring. They might also function as storage sites for carbohydrates and nitrogen (N). We hence hypothesized that whole-plant allocation of carbohydrates and N to storage in stems and roots may be lower in evergreen than in deciduous species. We selected three species pairs consisting of an evergreen and a related deciduous species: Mahonia aquifolium (Pursh) Nutt. and Berberis vulgaris L. (Berberidaceae), Prunus laurocerasus L. and Prunus serotina Ehrh. (Rosaceae), and Viburnum rhytidophyllum Hemsl. and Viburnum lantana L. (Adoxaceae). Seedlings were grown outdoors in pots and harvested on two dates during the growing season for the determination of biomass, carbohydrate and N allocation ratios. Plant size-adjusted pools of nonstructural carbohydrates in stems and roots were lower in the evergreen species of Berberidaceae and Adoxaceae, and the slope of the carbohydrate pool vs plant biomass relationship was lower in the evergreen species of Rosaceae compared with the respective deciduous species, consistent with the leading hypothesis. Pools of N in stems and roots, however, did not vary with leaf habit. In all species, foliage contained more than half of the plant's nonstructural carbohydrate pool and, in late summer, also more than half of the plant's N pool, suggesting that in juvenile individuals of evergreen species, leaves may be a major storage site. Additionally, we hypothesized that concentration of defensive phenolic compounds in leaves should be higher in evergreen than in deciduous species, because the lower carbohydrate pool in stems and roots of the former restricts their capacity for regrowth following herbivory and also because of the need to protect their longer-living foliage. Our results did not support this hypothesis, suggesting that evergreen plants may rely predominantly on structural defenses. In summary, our study indicates that leaf habit has

Mesenchymal Stem Cells in the Bone Marrow Provide a Supportive Niche for Early Disseminated Breast Tumor-Initiating Cells

Science.gov (United States)

2011-04-01

Laboratory Summer internship Responsibilities: - Making agar plates - Maintaining cotton plant population - Glassware 2 Curriculum...undergraduate non-science majors in Heredity and Society Lab Research Interests: - Cancer Biology/Genetics - Cancer metastasis - Stem cell

Shading Contributes to the Reduction of Stem Mechanical Strength by Decreasing Cell Wall Synthesis in Japonica Rice (Oryza sativa L.

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Longmei Wu

2017-05-01

Full Text Available Low solar radiation caused by industrial development and solar dimming has become a limitation in crop production in China. It is widely accepted that low solar radiation influences many aspects of plant development, including slender, weak stems and susceptibility to lodging. However, the underlying mechanisms are not well understood. To clarify how low solar radiation affects stem mechanical strength formation and lodging resistance, the japonica rice cultivars Wuyunjing23 (lodging-resistant and W3668 (lodging-susceptible were grown under field conditions with normal light (Control and shading (the incident light was reduced by 60% with a black nylon net. The yield and yield components, plant morphological characteristics, the stem mechanical strength, cell wall components, culm microstructure, gene expression correlated with cellulose and lignin biosynthesis were measured. The results showed that shading significantly reduced grain yield attributed to reduction of spikelets per panicles and grain weight. The stem-breaking strength decreased significantly under shading treatment; consequently, resulting in higher lodging index in rice plant in both varieties, as revealed by decreased by culm diameter, culm wall thickness and increased plant height, gravity center height. Compared with control, cell wall components including non-structural carbohydrate, sucrose, cellulose, and lignin reduced quite higher. With histochemical straining, shading largely reduced lignin deposition in the sclerenchyma cells and vascular bundle cells compared with control, and decreased cellulose deposition in the parenchyma cells of culm tissue in both Wuyunjing23 and W3668. And under shading condition, gene expression involved in secondary cell wall synthesis, OsPAL, OsCOMT, OsCCoAOMT, OsCCR, and OsCAD2, and primary cell wall synthesis, OsCesA1, OsCesA3, and OsCesA8 were decreased significantly. These results suggest that gene expression involved in the reduction of

Shading Contributes to the Reduction of Stem Mechanical Strength by Decreasing Cell Wall Synthesis in Japonica Rice (Oryza sativa L.).

Science.gov (United States)

Wu, Longmei; Zhang, Wujun; Ding, Yanfeng; Zhang, Jianwei; Cambula, Elidio D; Weng, Fei; Liu, Zhenghui; Ding, Chengqiang; Tang, She; Chen, Lin; Wang, Shaohua; Li, Ganghua

2017-01-01

Low solar radiation caused by industrial development and solar dimming has become a limitation in crop production in China. It is widely accepted that low solar radiation influences many aspects of plant development, including slender, weak stems and susceptibility to lodging. However, the underlying mechanisms are not well understood. To clarify how low solar radiation affects stem mechanical strength formation and lodging resistance, the japonica rice cultivars Wuyunjing23 (lodging-resistant) and W3668 (lodging-susceptible) were grown under field conditions with normal light (Control) and shading (the incident light was reduced by 60%) with a black nylon net. The yield and yield components, plant morphological characteristics, the stem mechanical strength, cell wall components, culm microstructure, gene expression correlated with cellulose and lignin biosynthesis were measured. The results showed that shading significantly reduced grain yield attributed to reduction of spikelets per panicles and grain weight. The stem-breaking strength decreased significantly under shading treatment; consequently, resulting in higher lodging index in rice plant in both varieties, as revealed by decreased by culm diameter, culm wall thickness and increased plant height, gravity center height. Compared with control, cell wall components including non-structural carbohydrate, sucrose, cellulose, and lignin reduced quite higher. With histochemical straining, shading largely reduced lignin deposition in the sclerenchyma cells and vascular bundle cells compared with control, and decreased cellulose deposition in the parenchyma cells of culm tissue in both Wuyunjing23 and W3668. And under shading condition, gene expression involved in secondary cell wall synthesis, OsPAL, OsCOMT, OsCCoAOMT, OsCCR , and OsCAD2 , and primary cell wall synthesis, OsCesA1, OsCesA3 , and OsCesA8 were decreased significantly. These results suggest that gene expression involved in the reduction of lignin and