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Sample records for alfalfa plants grown

  1. Antioxidant responses in soybean and alfalfa plants grown in DDTs contaminated soils: Useful variables for selecting plants for soil phytoremediation?

    PubMed

    Mitton, Francesca M; Ribas Ferreira, Josencler L; Gonzalez, Mariana; Miglioranza, Karina S B; Monserrat, José M

    2016-06-01

    Phytoremediation is a low-cost alternative technology based on the use of plants to remove pollutants from the environment. Persistent organic pollutants such as DDTs with a long half-life in soils are attractive candidates for remediation. This study aimed to determine the potential of antioxidant response use in the evaluation of plants' tolerance for selecting species in phytoremediation purposes. Alfalfa and soybean plants were grown in DDT contaminated soils. After 60days, growth, protein content, antioxidant capacity, GST activity, concentration of proteic and non-proteic thiol groups, chlorophyll content and carotenoid content were measured in plant tissues. Results showed no effect on alfalfa or soybean photosynthetic pigments but different responses in the protein content, antioxidant capacity, GST activity and thiol groups on roots, stems and leaves, indicating that DDTs affected both species. Soybean showed higher susceptibility than alfalfa plants due to the lower antioxidant capacity and GST activity in leaves, in spite of having the lowest DDT accumulation. This study provides new insights into the role of oxidative stress as an important component of the plant's response to DDT exposure.

  2. Plant bugs on alfalfa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper treats the most important plant bugs, or Miridae, found on alfalfa in North America. It is estimated that more than 10 species of plant bugs have the potential to develop on this important forage legume. Of these, the alfalfa plant bug (Adelphocoris lineolatus), pale legume bug (Lygus e...

  3. Alfalfa

    MedlinePlus

    ... your health provider.Medications that increase sensitivity to sunlight (Photosensitizing drugs)Some medications can increase sensitivity to sunlight. Large doses of alfalfa might also increase your ...

  4. Plant development controls leaf area expansion in alfalfa plants competing for light

    PubMed Central

    Baldissera, Tiago Celso; Frak, Ela; Carvalho, Paulo Cesar de Faccio; Louarn, Gaëtan

    2014-01-01

    Background and Aims The growth of crops in a mixture is more variable and difficult to predict than that in pure stands. Light partitioning and crop leaf area expansion play prominent roles in explaining this variability. However, in many crops commonly grown in mixtures, including the forage species alfalfa, the sensitivity and relative importance of the physiological responses involved in the light modulation of leaf area expansion are still to be established. This study was designed to assess the relative sensitivity of primary shoot development, branching and individual leaf expansion in alfalfa in response to light availability. Methods Two experiments were carried out. The first studied isolated plants to assess the potential development of different shoot types and growth periods. The second consisted of manipulating the intensity of competition for light using a range of canopies in pure and mixed stands at two densities so as to evaluate the relative effects on shoot development, leaf growth, and plant and shoot demography. Key Results Shoot development in the absence of light competition was deterministic (constant phyllochrons of 32·5 °Cd and 48·2 °Cd for primary axes and branches, branching probability of 1, constant delay of 1·75 phyllochron before axillary bud burst) and identical irrespective of shoot type and growth/regrowth periods. During light competition experiments, changes in plant development explained most of the plant leaf area variations, with average leaf size contributing to a lesser extent. Branch development and the number of shoots per plant were the leaf area components most affected by light availability. Primary axis development and plant demography were only affected in situations of severe light competition. Conclusions Plant leaf area components differed with regard to their sensitivity to light competition. The potential shoot development model presented in this study could serve as a framework to integrate light responses

  5. Establishing alfalfa in corn silage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    According to recent agricultural statistics, alfalfa was planted on 0.44 million acres and harvested from 2.2 million acres, and corn silage was planted and harvested from 1.0 million acres per year in Wisconsin. Because both crops are often grown in rotation, alfalfa could be interseeded at corn pl...

  6. Establishing alfalfa in silage corn

    Technology Transfer Automated Retrieval System (TEKTRAN)

    According to recent agricultural statistics, alfalfa was planted on 0.44 million acres and harvested from 2.2 million acres and silage corn was planted and harvested from 1.0 million acres per year in Wisconsin. Because both crops are often grown in rotation, alfalfa could be interseeded at corn pla...

  7. Alfalfa (Medicago sativa L.).

    PubMed

    Fu, Chunxiang; Hernandez, Timothy; Zhou, Chuanen; Wang, Zeng-Yu

    2015-01-01

    Alfalfa (Medicago sativa L.) is a high-quality forage crop widely grown throughout the world. This chapter describes an efficient protocol that allows for the generation of large number of transgenic alfalfa plants by sonication-assisted Agrobacterium-mediated transformation. Binary vectors carrying different selectable marker genes that confer resistance to phosphinothricin (bar), kanamycin (npt II), or hygromycin (hph) were used to generate transgenic alfalfa plants. Intact trifoliates collected from clonally propagated plants in the greenhouse were sterilized with bleach and then inoculated with Agrobacterium strain EHA105. More than 80 % of infected leaf pieces could produce rooted transgenic plants in 4-5 months after Agrobacterium-mediated transformation.

  8. Genetically engineered alfalfa and feral alfalfa plants: What should growers know?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alfalfa (Medicago sativa subsp. sativa L) is the world’s most important forage crop. The western United States is the most important production area for both alfalfa forage and alfalfa seed. Alfalfa was the first major perennial genetically-engineered (GE)crop and a GE trait for resistance to glypho...

  9. Relationship between photosynthetic capacity, nitrogen assimilation and nodule metabolism in alfalfa (Medicago sativa) grown with sewage sludge.

    PubMed

    Antolín, M Carmen; Fiasconaro, M Laura; Sánchez-Díaz, Manuel

    2010-10-15

    Sewage sludge has been used as N fertilizer because it contains some of inorganic N, principally as nitrate and ammonium ions. However, sewage sludge addition to legumes could result in impaired nodule metabolism due to the presence of inorganic N from sludge. A greenhouse experiment was conducted to examine the effects of sewage sludge on growth, photosynthesis, nitrogen assimilation and nodule metabolism in alfalfa (Medicago sativa L. cv. Aragón). Plants were grown in pots with a mixture of perlite and vermiculite (2:1, v/v). The experiment included three treatments: (1) plants inoculated with rhizobia and amended with sewage sludge at rate of 10% (w/w) (RS); (2) plants inoculated with rhizobia without any amendment (R); and (3) non-inoculated plants fed with ammonium nitrate (N). N(2)-fixing plants had lower growth and sucrose phosphate synthase activity but higher photosynthesis than nitrate-fed plants because they compensated the carbon cost of the rhizobia. However, sewage sludge-treated plants evidenced a loss of carbon sink strength due to N(2) fixation by means of decreased photosynthetic capacity, leaf chlorophylls and N concentration in comparison to untreated plants. Sewage sludge did no affect nodulation but decreased nodule enzyme activities involved in carbon and N metabolisms that may lead to accumulation of toxic N-compounds.

  10. Prohexadione-calcium responsive alfalfa varieties ensure success of corn-interseeded alfalfa production systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent USDA-NASS data indicate alfalfa and corn were planted on about 0.8 and 1.9 million hectares per year, respectively, in the Northeast, Great Lakes, Upper Midwest, and Northern Mountain regions the USA. Because both crops are often grown in rotation, alfalfa could be interseeded at corn plantin...

  11. Enhancement of lead uptake by alfalfa (Medicago sativa) using EDTA and a plant growth promoter.

    PubMed

    López, Martha L; Peralta-Videa, Jose R; Benitez, Tenoch; Gardea-Torresdey, Jorge L

    2005-10-01

    Phytoremediation is a novel cleanup technology for the removal of contaminants from polluted waters and soils. In phytoremediation, the plant uptake capability and the availability of the pollutant in the media are important. Here we show the results of a study on the combined effects of ethylenediaminetetraacetic acid (EDTA) and the phytohormone indole-3-acetic acid (IAA) on Pb uptake by Medicago sativa (alfalfa). Plants were grown in hydroponics media containing a nutrient solution amended with Pb at 0.2mM and different combinations of EDTA, and IAA. After 10d of treatment, the Pb content in plant tissues was quantified using an Inductively Coupled Plasma Optical Emission Spectrometer (ICP/OES). The results showed that the combination of 100 microM IAA/0.2 mM EDTA increased the Pb accumulation in leaves by about 2800% and by about 600%, as compared to Pb content in leaves of plants exposed to Pb alone and those cultivated with Pb/EDTA, respectively. These results indicate that non-metal hyperaccumulator plants could increase their hyperaccumulating potential without genetic manipulation.

  12. Transgenic Alfalfa Plants Expressing the Sweetpotato Orange Gene Exhibit Enhanced Abiotic Stress Tolerance

    PubMed Central

    Wang, Zhi; Ke, Qingbo; Kim, Myoung Duck; Kim, Sun Ha; Ji, Chang Yoon; Jeong, Jae Cheol; Lee, Haeng-Soon; Park, Woo Sung; Ahn, Mi-Jeong; Li, Hongbing; Xu, Bingcheng; Deng, Xiping; Lee, Sang-Hoon; Lim, Yong Pyo; Kwak, Sang-Soo

    2015-01-01

    Alfalfa (Medicago sativa L.), a perennial forage crop with high nutritional content, is widely distributed in various environments worldwide. We recently demonstrated that the sweetpotato Orange gene (IbOr) is involved in increasing carotenoid accumulation and enhancing resistance to multiple abiotic stresses. In this study, in an effort to improve the nutritional quality and environmental stress tolerance of alfalfa, we transferred the IbOr gene into alfalfa (cv. Xinjiang Daye) under the control of an oxidative stress-inducible peroxidase (SWPA2) promoter through Agrobacterium tumefaciens-mediated transformation. Among the 11 transgenic alfalfa lines (referred to as SOR plants), three lines (SOR2, SOR3, and SOR8) selected based on their IbOr transcript levels were examined for their tolerance to methyl viologen (MV)-induced oxidative stress in a leaf disc assay. The SOR plants exhibited less damage in response to MV-mediated oxidative stress and salt stress than non-transgenic plants. The SOR plants also exhibited enhanced tolerance to drought stress, along with higher total carotenoid levels. The results suggest that SOR alfalfa plants would be useful as forage crops with improved nutritional value and increased tolerance to multiple abiotic stresses, which would enhance the development of sustainable agriculture on marginal lands. PMID:25946429

  13. Effect of chemical inhibitors of photorespiration on nitrogenase activity in nodulated alfalfa plants.

    PubMed

    Bedmar, E J; Olivares, J

    1980-12-01

    Nitrogen fixation (measured as acetylene reduction) by whole nodulated alfalfa plants was stimulated when the plants were treated with isonicotinic acid hydracide (INH) and glyoxylate, both inhibitors of the glycolate pathway of carbohydrate metabolism, at concentrations of 300 and 100 mM, respectively. Reducing energetic loses caused by photorespiration results in an increase in the symbiotic nitrogen fixation.

  14. Adenylate cyclase activity in a higher plant, alfalfa (Medicago sativa).

    PubMed Central

    Carricarte, V C; Bianchini, G M; Muschietti, J P; Téllez-Iñón, M T; Perticari, A; Torres, N; Flawiá, M M

    1988-01-01

    An adenylate cyclase activity in Medicago sativa L. (alfalfa) roots was partially characterized. The enzyme activity remains in the supernatant fluid after centrifugation at 105,000 g and shows in crude extracts an apparent Mr of about 84,000. The enzyme is active with Mg2+ and Ca2+ as bivalent cations, and is inhibited by EGTA and by chlorpromazine. Calmodulin from bovine brain or spinach leaves activates this adenylate cyclase. PMID:3128270

  15. Effects of plant enzyme inactivation or sterilization on lipolysis and proteolysis in alfalfa silage.

    PubMed

    Ding, W R; Long, R J; Guo, X S

    2013-04-01

    This experiment studied the contribution of plant enzymes and microbial activity on lipolysis and proteolysis in ensiled alfalfa. Before ensiling, the wilted alfalfa was treated with plant enzyme inactivation by autoclaving or with sterilization by γ-ray irradiation. The treated alfalfa was then inoculated with commercial lactic acid bacteria inoculants and ensiled for 40 d. Alfalfa without treatment was ensiled as the control. The content of total fatty acid (FA) after ensiling decreased 43% in the control silage and 28% in the γ-ray-treated silage, but did not change in the autoclave-treated silage. Among the major FA (C16:0, C18:2n-6, C18:3n-3), a considerable increase was observed in proportion of C16:0 in the control silage as compared with fresh alfalfa; conversely, decreases in proportions of C18:2n-6 and C18:3n-3 occurred during ensilage. Silage treated with γ-ray radiation at ensiling had a smaller proportion of C16:0 and greater proportions of C18:2n-6 and C18:3n-3 than control silage. Autoclave treatment further decreased proportions of C16:0 and most of the other FA, and increased C18:2n-6 and C18:3n-3 proportions in comparison with γ-ray treatment. Proportions of C16:0, C18:2n-6, C18:3n-3 and other detected FA (except for the proportion of C15:0) did not differ between fresh forage and autoclave-treated silage. Remarkably, smaller nonprotein nitrogen content was observed in the autoclave-treated silage compared with the γ ray-treated silage or the control silage. These results indicated that an extensive lipolysis occurred during ensiling of alfalfa, and plant enzymes played a major role in lipolysis and proteolysis.

  16. Alfalfa hay induced primary photosensitization in horses.

    PubMed

    Puschner, B; Chen, X; Read, D; Affolter, V K

    2016-05-01

    Photosensitization, also known as photodermatitis, occurs when phototoxic or photoactive substances accumulate in the skin and interact with sunlight to result in an often severe, crusting, itching or painful dermatitis in unpigmented and/or lightly haired areas of the skin. Primary photosensitization, caused by direct ingestion of photosensitizing agents, has been reported anecdotally in horses after ingestion of alfalfa hay. Between 2004 and 2014, several large outbreaks of primary photosensitization in horses fed primarily alfalfa hay were investigated in California. Alfalfa hay samples were collected and carefully examined for the presence of known photosensitizing plants and pesticide residues but none were identified. Select hay samples were evaluated for unusual fungal infestation and for phototoxicity assay using a specific Candida albicans assay; results were negative. In the 2004 outbreak, a feeding study was conducted with three horses exclusively fed alfalfa hay that was suspected to have caused the outbreak. Two weeks after ingestion of alfalfa hay, two horses developed several lesions in non-pigmented skin characterized as chronic ulcerative and necrotizing dermatitis with superficial vasculitis, which was consistent with photosensitization. In the 2014 outbreak, seven different implicated alfalfa hay samples were analyzed for chlorophyll a and b, and pheophorbide a. These compounds had been suspected to play a role in alfalfa-induced primary photosensitization. The chlorophyll contents ranged from 0.90 to 2.30 mg/g in the alfalfa hay samples, compared to 1.37 and 2.94 mg/g in locally grown alfalfa and orchard grass hay. The pheophorbide a levels ranged from 3.36 to 89.87 µg/g in alfalfa samples compared to 81.39 and 42.33 µg/g in control alfalfa and orchard grass hay samples. These findings eliminate chlorophyll a, chlorophyll b, and pheophorbide a as possible causes for alfalfa-hay induced primary photosensitization.

  17. Ensifer, Phyllobacterium and Rhizobium species occupy nodules of Medicago sativa (alfalfa) and Melilotus alba (sweet clover) grown at a Canadian site without a history of cultivation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phage resistant and susceptible bacteria from nodules of alfalfa and sweet clover grown at a site without a known history of cultivation, were identified as Ensifer, Rhizobium and Phyllobacterium species based on sequence analysis of ribosomal (16S and 23S rRNA)and protein encoding (atpD and recA) g...

  18. Characterization of Rhizobia from Ineffective Alfalfa Nodules: Ability to Nodulate Bean Plants [Phaseolus vulgaris (L.) Savi.] †

    PubMed Central

    Eardly, Bertrand D.; Hannaway, David B.; Bottomley, Peter J.

    1985-01-01

    This study was initiated to characterize Rhizobium isolates obtained from root nodules of ineffectively nodulated, field-grown alfalfa (Medicago sativa L.) plants. The purpose was to determine if these isolates possessed characteristics which would explain either their ineffectiveness in N2 fixation or their apparent ability to tolerate the moderately acid soil conditions from which they originated. Isolates were characterized by analysis of growth rate, 39°C tolerance, acid production on conventional media, and symbiotic performance. All isolates were ineffective in N2 fixation on alfalfa, and they contained one or more anomalous characteristics. These included either slow growth rate, lack of 39°C tolerance, or lack of acid production on conventional media. Infectiveness tests on a broad range of legumes revealed that the isolates formed root nodules on M. sativa, Medicago lupulina L., and Phaseolus vulgaris (L.) Savi. (common bean). These results provide evidence that, in some situations, ineffective nodulation of M. sativa in the field may be due to the presence of promiscuous, native Rhizobium species. PMID:16346942

  19. Micromonospora from nitrogen fixing nodules of alfalfa (Medicago sativa L.). A new promising Plant Probiotic Bacteria.

    PubMed

    Martínez-Hidalgo, Pilar; Galindo-Villardón, Purificación; Trujillo, Martha E; Igual, José M; Martínez-Molina, Eustoquio

    2014-09-17

    Biotic interactions can improve agricultural productivity without costly and environmentally challenging inputs. Micromonospora strains have recently been reported as natural endophytes of legume nodules but their significance for plant development and productivity has not yet been established. The aim of this study was to determine the diversity and function of Micromonospora isolated from Medicago sativa root nodules. Micromonospora-like strains from field alfalfa nodules were characterized by BOX-PCR fingerprinting and 16S rRNA gene sequencing. The ecological role of the interaction of the 15 selected representative Micromonospora strains was tested in M. sativa. Nodulation, plant growth and nutrition parameters were analyzed. Alfalfa nodules naturally contain abundant and highly diverse populations of Micromonospora, both at the intra- and at interspecific level. Selected Micromonospora isolates significantly increase the nodulation of alfalfa by Ensifer meliloti 1021 and also the efficiency of the plant for nitrogen nutrition. Moreover, they promote aerial growth, the shoot-to-root ratio, and raise the level of essential nutrients. Our results indicate that Micromonospora acts as a Rhizobia Helper Bacteria (RHB) agent and has probiotic effects, promoting plant growth and increasing nutrition efficiency. Its ecological role, biotechnological potential and advantages as a plant probiotic bacterium (PPB) are also discussed.

  20. Ensifer, Phyllobacterium and Rhizobium species occupy nodules of Medicago sativa (alfalfa) and Melilotus alba (sweet clover) grown at a Canadian site without a history of cultivation.

    PubMed

    Bromfield, E S P; Tambong, J T; Cloutier, S; Prévost, D; Laguerre, G; van Berkum, P; Thi, T V Tran; Assabgui, R; Barran, L R

    2010-02-01

    Phage-resistant and -susceptible bacteria from nodules of alfalfa and sweet clover, grown at a site without a known history of cultivation, were identified as diverse genotypes of Ensifer, Rhizobium and Phyllobacterium species based on sequence analysis of ribosomal (16S and 23S rRNA) and protein-encoding (atpD and recA) genes, Southern hybridization/RFLP and a range of phenotypic characteristics. Among phage-resistant bacteria, one genotype of Rhizobium sp. predominated on alfalfa (frequency approximately 68 %) but was recovered infrequently ( approximately 1 %) from sweet clover. A second genotype was isolated infrequently only from alfalfa. These genotypes fixed nitrogen poorly in association with sweet clover and Phaseolus vulgaris, but were moderately effective with alfalfa. They produced a near-neutral reaction on mineral salts agar containing mannitol, which is atypical of the genus Rhizobium. A single isolate of Ensifer sp. and two of Phyllobacterium sp. were recovered only from sweet clover. All were highly resistant to multiple antibiotics. Phylogenetic analysis indicated that Ensifer sp. strain T173 is closely related to, but separate from, the non-symbiotic species 'Sinorhizobium morelense'. Strain T173 is unique in that it possesses a 175 kb symbiotic plasmid and elicits ineffective nodules on alfalfa, sweet clover, Medicago lupulina and Macroptilium atropurpureum. The two Phyllobacterium spp. were non-symbiotic and probably represent bacterial opportunists. Three genotypes of E. meliloti that were symbiotically effective with alfalfa and sweet clover were encountered infrequently. Among phage-susceptible isolates, two genotypes of E. medicae were encountered infrequently and were highly effective with alfalfa, sweet clover and Medicago polymorpha. The ecological and practical implications of the findings are discussed.

  1. Effect of foliar feeding on nitrogen assimilation in alfalfa plants at insufficient molybdenum supply.

    PubMed

    Hristozkova, Marieta; Geneva, Maria; Stancheva, Ira

    2009-06-01

    The influence of foliar feeding on the nitrogen assimilation in alfalfa plants under conditions of Mo shortage was studied. It was established that foliar fertilization with 0.3% solution of Agroleaf® resulted in increase of nitrogen fixation and nitrogen assimilation in the absence of Mo. Insufficient molybdenum supply leads to significant reduction of plant Mo content and nitrogen-fixing activity, while stress induced amino acids as alanine, GABA, threonine, proline and serine increased repeatedly. The negative effect of Mo deficiency on the enzyme activities related to the primary nitrogen assimilation (NR, GS, GOGAT) and plant growth diminished due to the foliar absorbed nutrients.

  2. Effect of air sparging on fate and transport of trichloroethylene in chambers with alfalfa plants

    SciTech Connect

    Zhang, Q.; Hu, J.; Erickson, L.E.; Davis, L.C.

    1997-12-31

    To study the effect of air sparging in soil with trichloroethylene present as a dense nonaqueous phase, air was supplied through pipes installed at the bottom of two chambers planted with alfalfa. Air input rate was 2.14 L/m{sup 2}/day. The fate of trichloroethylene (TCE) was investigated by monitoring TCE concentration in both outflow groundwater and soil gas. Comparison of these results with those of the previous study without air sparging indicates that air sparging appreciably increases the groundwater concentration of TCE. The soil gas at the surface shows even greater concentration difference. The flux of TCE to the atmosphere is increased significantly by air input. Accordingly, the authors can conclude that air sparging improved mass transfer of TCE from the nonaqueous phase to groundwater phase. Air sparging appeared to negatively impact the health of the alfalfa because of the elevated TCE present in the vadose zone of the chamber.

  3. Stress-related phenomena and detoxification mechanisms induced by common pharmaceuticals in alfalfa (Medicago sativa L.) plants.

    PubMed

    Christou, Anastasis; Antoniou, Chrystalla; Christodoulou, Charalampia; Hapeshi, Evroula; Stavrou, Ioannis; Michael, Costas; Fatta-Kassinos, Despo; Fotopoulos, Vasileios

    2016-07-01

    Pharmaceutically active compounds (PhACs) have been recently shown to exert phytotoxic effects. The present study explores the uptake, systemic translocation, and abiotic stress responses and detoxification mechanisms induced by the exposure of alfalfa plants grown in sand under greenhouse conditions to four common, individually applied PhACs (10μgL(-1)) (diclofenac, sulfamethoxazole, trimethoprim, 17a-ethinylestradiol) and their mixture. Stress physiology markers (lipid peroxidation, proline, H2O2 and NO content, antioxidant activity assays) and gene expression levels of key plant detoxification components (including glutathione S-transferases, GST7, GST17; superoxide dismutases, CuZnSOD, FeSOD; proton pump, H(+)-ATP, and cytochrome c oxidase, CytcOx), were evaluated. PhACs were detected in significantly higher concentrations in roots compared with leaves. Stress related effects, manifested via membrane lipid peroxidation and oxidative burst, were local (roots) rather than systemic (leaves), and exacerbated when the tested PhACs were applied in mixture. Systemic accumulation of H2O2 in leaves suggests its involvement in signal transduction and detoxification responses. Increased antioxidant enzymatic activities, as well as upregulated transcript levels of GST7, GST17, H(+)-ATPase and CytcOx, propose their role in the detoxification of the selected PhACs in plants. The current findings provide novel biochemical and molecular evidence highlighting the studied PhACs as an emerging abiotic stress factor, and point the need for further research on wastewater flows under natural agricultural environments.

  4. EFFECT OF INDOLE-3-ACETIC ACID, KINETIN, AND ETHYLENEDIAMINETETRAACETIC ACID ON PLANT GROWTH AND UPTAKE AND TRANSLOCATION OF LEAD, MICRONUTRIENTS, AND MACRONUTRIENTS IN ALFALFA PLANTS.

    PubMed

    López, Martha Laura; Peralta-Videa, José R; Parsons, Jason G; Gardea-Torresdey, Jorge L; Duarte-Gardea, Maria

    2009-02-01

    Alfalfa plants germinated and grown for 15 d in soil containing 80 mg Pb kg(-1) were treated with ethylenediaminetetraacetic acid (EDTA) at 0.8 mM and indole-3-acetic acid-kinetin (IAA-KN) at 100 μM. Fifteen days after the treatment application, the concentration of lead (Pb), macronutrients, and micronutrients was determined using inductively coupled plasma/optical emission spectroscopy. The chlorophyll content and plant growth were also measured. Roots of plants exposed to Pb alone, Pb-EDTA, and Pb-EDTA-IAA-KN had 160, 140, and 150 mg Pb kg(-1) DW, respectively. Pb was not detected in the stems of plants exposed to Pb alone; however, stems of plants treated with EDTA and EDTA-IAA-KN had 78 and 142 mg Pb kg(-1) DW, respectively. While the Pb concentration in leaves of plants treated with EDTA and EDTA-IAA-KN was 92 and 127 mg kg(-1) DW, respectively. In addition, EDTA and EDTA-IAA-KN significantly increased the translocation of zinc and manganese to leaves. The x-ray absorption spectroscopic studies demonstrated that Pb(II) was transported from roots to leaves without a change in the oxidation state.

  5. [Degradation process and plant diversity of alfalfa grassland in North Loess Plateau of China].

    PubMed

    Li, Yuyua; Shao, Ming'an

    2005-12-01

    Vegetation recovery and reconstruction is the key of ecosystem restoration in the North Loess Plateau. With the Liudaogou catchment of Shenmu County, Shaanxi Province as test area, this paper studied the dynamics of the plant diversity of artificial alfalfa (Medicago sativa) grassland during its degradation process. The results showed that the degradation process of the grassland could be divided into three stages, i.e., artificial alfalfa grassland stage (1-6 yrs), transitional stage from artificial to natural grassland (6-10 yrs), and secondary natural grassland stage dominated by Stipa bungeana ( >10 yrs). In the whole degradation process from 1-to 30-yrs, 32 species belonging to 13 families and 28 genera were found, of which, 90% appeared in the initial 6-yrs. The dynamics of accumulatively appeared family, genus, and species in the vegetation succession process were well described by logarithmic function. During the process of community succession, the species richness (Gleason index and Margalef index),plant diversity (Shannon-Wiener index), and Pielou evenness index were changed with a similar tendency, i.e., increased more rapidly at the first stage, and the climax phase appeared in the second stage. The plant diversity and evenness decreased slightly, and gradually became stable later. Planting alfalfa could markedly accelerate the natural vegetation succession process in the forest-steppe ecotone of Loess Plateau, mainly due to the intensive soil water consumption of artificial grassland, which accelerated the process of soil aridification. To develop artificial grasslands in the Loess Plateau is an optimal joint between accelerating natural vegetation recovery and increasing farmers' income by stockbreeding, and is also a favorable paradigm both for the ecological and for the economic benefits in the eco-environmental construction in West China.

  6. Nucleolus in clinostat-grown plants

    SciTech Connect

    Shen-Miller, J.; Dannenhoffer, J. ); Hinchman, R. )

    1991-05-01

    The clinostat is an apparatus that is used to mimic zero gravity in studies of plant growth in the absence of gravitropic response. Clinostat-grown tissue cultures of carrot exhibit significant increases both in the number of nuclei containing more than one nucleolus and in nucleolar volume. Oat seedlings germinated and grown on clinostats exhibit a decreased rate of shoot elongation, increased tissue sensitivity to applied auxin, and an increased response to gravitropic stimulation. Clinostat treatment clearly affects plant metabolism. The nucleolus is the region in the nucleus where ribosome synthesis and assembly take place. The 18S, 5.8S, and 25S ribosomal genes, in tandem units, are located in the nucleolus. Ribosomes orchestrate the production of all proteins that are necessary for the maintenance of cell growth, development, and survival. A full study of the effects of nullification of gravitropism, by clinostat rotation, on nucleolar development in barley has been initiated. The authors study developmental changes of nucleolar number and diameter in clinostat-grown root tissues. Preliminary results show that barley roots exhibit changes in nucleolar number and diameter. Growth rates of barley root and shoot also appear to be reduced, in measurements of both length and weight.

  7. Diversity cascades in alfalfa fields: from plant quality to agroecosystem diversity.

    PubMed

    Pearson, Clark V; Massad, Tara J; Dyer, Lee A

    2008-08-01

    To examine top-down and bottom-up influences on managed terrestrial communities, we manipulated plant resources and arthropod abundance in alfalfa (Medicago sativa L.) fields. We modified arthropod communities using three nonfactorial manipulations: pitfall traps to remove selected arthropods, wooden crates to create habitat heterogeneity, and an arthropod removal treatment using a reversible leaf blower. These manipulations were crossed with fertilizer additions, which were applied to half of the plots. We found strong effects of fertilizer on plant quality and biomass, and these effects cascaded up to increase herbivore abundance and diversity. The predator community also exhibited a consistent positive effect on the maintenance of herbivore species richness and abundance. These top-down changes in arthropods did not cascade down to affect plant biomass; however, plant quality (saponin content) increased with higher herbivore densities. These results corroborate previous studies in alfalfa that show complex indirect effects, such as trophic cascades, can operate in agricultural systems, but the specifics of the interactions depend on the assemblages of arthropods involved.

  8. Do glyphosate resistant feral plants and hay fields spread the transgene to conventional alfalfa seed fields?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In addition to meeting domestic needs, large amounts of alfalfa seed and hay produced in the US are being exported overseas. Because alfalfa is an insect pollinated crop, gene flow is a concern. Adding to this alfalfa readily naturalizes along roadsides, irrigation ditches, and unmanaged habitats; a...

  9. Distribution of glassy-winged sharpshooter and threecornered alfalfa hopper on plant hosts in the San Joaquin valley

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Homalodisca vitripennis Germar and Spissistilus festinus Say populations were surveyed bimonthly for 14 months in Kern County at five agricultural sites made up of a variety of potential host plants. Additionally, S. festinus populations were surveyed in four alfalfa fields in Kern and Tulare Counti...

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

    PubMed

    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.

  11. Evaluation of aluminum indices to predict aluminum toxicity to plants grown in nutrient solutions

    SciTech Connect

    Alva, A.K.; Blamey, F.P.C.; Edwards, D.G.; Asher, C.J.

    1986-01-01

    Difficulty has been experienced in establishing a suitable aluminum (Al) index to predict Al toxicity to plants grown in nutrient solutions with a wide range of properties. In the present study, relationships were evaluated between root length and (i) concentration of total Al, (ii) concentration of monomeric Al, and (iii) the sum of the activities of monomeric Al species (..sigma..a/sub Al mono/) in solution. Results are reported for soybean (Glycine max (L.) Merr.), subterranean clover (Trifolium subterraneum L.), alfalfa (Medicago sativa L.), and sunflower (Helianthus annuus L.). Total Al concentration in solution, comprising polymeric and monomeric Al species, was a poor index of Al toxicity, confirming the hypothesis that only monomeric Al is toxic to root growth. In solutions with widely differing composition, the concentration of monomeric Al also proved unsatisfactory due to ionic strength effects on the activities of monomeric Al species. ..sigma..a/sub Al mono/ was the best index of Al toxicity, accounting for 72 to 92% of the variation in root length depending on the plant species. Root length was reduced by 50% at ..sigma..a/sub Al mono/ of 7-16 ..mu..M in soybean, 13 ..mu..M in subterranean clover and alfalfa, and 11 ..mu..M in sunflower.

  12. Manure use on alfalfa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Manure application to alfalfa is often necessary because of limited application windows during the year and limited land-to-livestock ratios to meet Comprehensive Nutrient Management Plan requirements. Manure applied before alfalfa planting or during production can improve yield and performance of t...

  13. Alfalfa witches'-broom

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alfalfa witches'-broom was first reported in 1969 in Australia and later in South Africa, Canada, and Saudi Arabia. More recently, specific phytoplasmas associated with alfalfa witches'-broom have been identified from symptomatic plants in the United States (Wisconsin), Italy, Lithuania, Oman, Ira...

  14. Manure on alfalfa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many managers of crop-livestock operations could, or need to, utilize alfalfa fields in their manure management plans. The advantages to manure application on alfalfa need to be considered in the context of some potential concerns – plant damage from manure or wheel traffic, pathogen transmission in...

  15. Assessment of heat shock protein 70 induction by heat in alfalfa varieties and constitutive overexpression in transgenic plants.

    PubMed

    Ferradini, Nicoletta; Iannacone, Rina; Capomaccio, Stefano; Metelli, Alessandra; Armentano, Nadia; Semeraro, Lucia; Cellini, Francesco; Veronesi, Fabio; Rosellini, Daniele

    2015-01-01

    Heat shock proteins (HSPs) are molecular chaperones involved in many cellular functions. It has been shown that mammalian cytosolic HSP70 binds antigenic peptides mediating the activation of the immune system, and that it plays a determining role in tumour immunogenicity. This suggests that HSP70 may be used for the production of conjugated vaccines. Human and plant HSPs share high sequence similarity and some important biological functions in vitro. In addition, plant HSPs have no endotoxic side effects. Extraction of HSP70 from plants for use as vaccine adjuvant requires enhancing its concentration in plant tissues. In this work, we explored the possibility to produce HSP70 in both transgenic and non-transgenic plants, using alfalfa as a model species. First, a transcriptional analysis of a constitutive and an inducible HSP70 genes was conducted in Arabidopsis thaliana. Then the coding sequence of the inducible form was cloned and introduced into alfalfa by Agrobacterium-mediated transformation, and the accumulation of the protein in leaf tissue of transgenic plants was demonstrated. We also tested diverse alfalfa varieties for heat-inducible expression of endogenous HSP70, revealing variety-specific responses to heat shock.

  16. Carboxylate metabolism in sugar beet plants grown with excess Zn.

    PubMed

    Sagardoy, R; Morales, F; Rellán-Álvarez, R; Abadía, A; Abadía, J; López-Millán, A F

    2011-05-01

    The effects of Zn excess on carboxylate metabolism were investigated in sugar beet (Beta vulgaris L.) plants grown hydroponically in a growth chamber. Root extracts of plants grown with 50 or 100μM Zn in the nutrient solution showed increases in several enzymatic activities related to organic acid metabolism, including citrate synthase and phosphoenolpyruvate carboxylase, when compared to activities in control root extracts. Root citric and malic acid concentrations increased in plants grown with 100μM Zn, but not in plants grown with 50μM Zn. In the xylem sap, plants grown with 50 and 100μM Zn showed increases in the concentrations of citrate and malate compared to the controls. Leaves of plants grown with 50 or 100μM Zn showed increases in the concentrations of citric and malic acid and in the activities of citrate synthase and fumarase. Leaf isocitrate dehydrogenase increased only in plants grown with 50μM Zn when compared to the controls. In plants grown with 300μM Zn, the only enzyme showing activity increases in root extracts was citrate synthase, whereas the activities of other enzymes decreased compared to the controls, and root citrate concentrations increased. In the 300μM Zn-grown plants, the xylem concentrations of citric and malic acids were higher than those of controls, whereas in leaf extracts the activity of fumarase increased markedly, and the leaf citric acid concentration was higher than in the controls. Based on our data, a metabolic model of the carboxylate metabolism in sugar beet plants grown under Zn excess is proposed.

  17. The sunflower transcription factor HaHB11 confers tolerance to water deficit and salinity to transgenic Arabidopsis and alfalfa plants.

    PubMed

    Cabello, Julieta V; Giacomelli, Jorge I; Gómez, María C; Chan, Raquel L

    2016-11-22

    Homeodomain-leucine zipper (HD-Zip) transcription factors are unique to the plant kingdom; members of subfamily I are known to be involved in abiotic stress responses. HaHB11 belongs to this subfamily and it was previously shown that it is able to confer improved yield and tolerance to flooding via a quiescent strategy. Here we show that HaHB11 expression is induced by ABA, NaCl and water deficit in sunflower seedlings and leaves. Arabidopsis transgenic plants expressing HaHB11, controlled either by its own promoter or by the constitutive 35S CaMV, presented rolled leaves and longer roots than WT when grown under standard conditions. In addition, these plants showed wider stems and more vascular bundles. To deal with drought, HaHB11 transgenic plants closed their stomata faster and lost less water than controls, triggering an enhanced tolerance to such stress condition and also to salinity stress. Concomitantly, ABA-synthesis and sensing related genes were differentially regulated in HaHB11 transgenic plants. Either under long-term salinity stress or mild drought stress, HaHB11 transgenic plants did not exhibit yield penalties. Moreover, alfalfa transgenic plants were generated which also showed enhanced drought tolerance. Altogether, the results indicated that HaHB11 was able to confer drought and salinity tolerance via a complex mechanism which involves morphological, physiological and molecular changes.

  18. Ractopamine uptake by alfalfa (Medicago sativa) and wheat (Triticum aestivum) from soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ractopamine is a beta adrenergic agonist used as a growth promoter in swine, cattle and turkeys. To test whether ractopamine has the potential to accumulate in plants grown in contaminated soil, a greenhouse study was conducted with alfalfa (Medicago sativa) and wheat (Triticum aestivum) grown in t...

  19. Plant physiology and proteomics reveals the leaf response to drought in alfalfa (Medicago sativa L.)

    PubMed Central

    Aranjuelo, Iker; Molero, Gemma; Erice, Gorka; Avice, Jean Christophe; Nogués, Salvador

    2011-01-01

    Despite its relevance, protein regulation, metabolic adjustment, and the physiological status of plants under drought is not well understood in relation to the role of nitrogen fixation in nodules. In this study, nodulated alfalfa plants were exposed to drought conditions. The study determined the physiological, metabolic, and proteomic processes involved in photosynthetic inhibition in relation to the decrease in nitrogenase (Nase) activity. The deleterious effect of drought on alfalfa performance was targeted towards photosynthesis and Nase activity. At the leaf level, photosynthetic inhibition was mainly caused by the inhibition of Rubisco. The proteomic profile and physiological measurements revealed that the reduced carboxylation capacity of droughted plants was related to limitations in Rubisco protein content, activation state, and RuBP regeneration. Drought also decreased amino acid content such as asparagine, and glutamic acid, and Rubisco protein content indicating that N availability limitations were caused by Nase activity inhibition. In this context, drought induced the decrease in Rubisco binding protein content at the leaf level and proteases were up-regulated so as to degrade Rubisco protein. This degradation enabled the reallocation of the Rubisco-derived N to the synthesis of amino acids with osmoregulant capacity. Rubisco degradation under drought conditions was induced so as to remobilize Rubisco-derived N to compensate for the decrease in N associated with Nase inhibition. Metabolic analyses showed that droughted plants increased amino acid (proline, a major compound involved in osmotic regulation) and soluble sugar (D-pinitol) levels to contribute towards the decrease in osmotic potential (Ψs). At the nodule level, drought had an inhibitory effect on Nase activity. This decrease in Nase activity was not induced by substrate shortage, as reflected by an increase in total soluble sugars (TSS) in the nodules. Proline accumulation in the nodule

  20. Leaf δ15N as a physiological indicator of the responsiveness of N2-fixing alfalfa plants to elevated [CO2], temperature and low water availability

    PubMed Central

    Ariz, Idoia; Cruz, Cristina; Neves, Tomé; Irigoyen, Juan J.; Garcia-Olaverri, Carmen; Nogués, Salvador; Aparicio-Tejo, Pedro M.; Aranjuelo, Iker

    2015-01-01

    The natural 15N/14N isotope composition (δ15N) of a tissue is a consequence of its N source and N physiological mechanisms in response to the environment. It could potentially be used as a tracer of N metabolism in plants under changing environmental conditions, where primary N metabolism may be complex, and losses and gains of N fluctuate over time. In order to test the utility of δ15N as an indicator of plant N status in N2-fixing plants grown under various environmental conditions, alfalfa (Medicago sativa L.) plants were subjected to distinct conditions of [CO2] (400 vs. 700 μmol mol−1), temperature (ambient vs. ambient +4°C) and water availability (fully watered vs. water deficiency—WD). As expected, increased [CO2] and temperature stimulated photosynthetic rates and plant growth, whereas these parameters were negatively affected by WD. The determination of δ15N in leaves, stems, roots, and nodules showed that leaves were the most representative organs of the plant response to increased [CO2] and WD. Depletion of heavier N isotopes in plants grown under higher [CO2] and WD conditions reflected decreased transpiration rates, but could also be related to a higher N demand in leaves, as suggested by the decreased leaf N and total soluble protein (TSP) contents detected at 700 μmol mol−1 [CO2] and WD conditions. In summary, leaf δ15N provides relevant information integrating parameters which condition plant responsiveness (e.g., photosynthesis, TSP, N demand, and water transpiration) to environmental conditions. PMID:26322051

  1. Leaf δ(15)N as a physiological indicator of the responsiveness of N2-fixing alfalfa plants to elevated [CO2], temperature and low water availability.

    PubMed

    Ariz, Idoia; Cruz, Cristina; Neves, Tomé; Irigoyen, Juan J; Garcia-Olaverri, Carmen; Nogués, Salvador; Aparicio-Tejo, Pedro M; Aranjuelo, Iker

    2015-01-01

    The natural (15)N/(14)N isotope composition (δ(15)N) of a tissue is a consequence of its N source and N physiological mechanisms in response to the environment. It could potentially be used as a tracer of N metabolism in plants under changing environmental conditions, where primary N metabolism may be complex, and losses and gains of N fluctuate over time. In order to test the utility of δ(15)N as an indicator of plant N status in N2-fixing plants grown under various environmental conditions, alfalfa (Medicago sativa L.) plants were subjected to distinct conditions of [CO2] (400 vs. 700 μmol mol(-1)), temperature (ambient vs. ambient +4°C) and water availability (fully watered vs. water deficiency-WD). As expected, increased [CO2] and temperature stimulated photosynthetic rates and plant growth, whereas these parameters were negatively affected by WD. The determination of δ(15)N in leaves, stems, roots, and nodules showed that leaves were the most representative organs of the plant response to increased [CO2] and WD. Depletion of heavier N isotopes in plants grown under higher [CO2] and WD conditions reflected decreased transpiration rates, but could also be related to a higher N demand in leaves, as suggested by the decreased leaf N and total soluble protein (TSP) contents detected at 700 μmol mol(-1) [CO2] and WD conditions. In summary, leaf δ(15)N provides relevant information integrating parameters which condition plant responsiveness (e.g., photosynthesis, TSP, N demand, and water transpiration) to environmental conditions.

  2. The elicitor-inducible alfalfa isoflavone reductase promoter confers different patterns of developmental expression in homologous and heterologous transgenic plants.

    PubMed Central

    Oommen, A; Dixon, R A; Paiva, N L

    1994-01-01

    In legumes, the synthesis of infection- and elicitor-inducible antimicrobial phytoalexins occurs via the isoflavonoid branch of the phenylpropanoid pathway. To study transcriptional regulation of isoflavonoid pathway-specific genes, we have isolated the gene encoding isoflavone reductase (IFR), which is the enzyme that catalyzes the penultimate step in the synthesis of the phytoalexin medicarpin in alfalfa. Chimeric gene fusions were constructed between 765- and 436-bp promoter fragments of the IFR gene and the beta-glucuronidase reporter gene and transferred to alfalfa and tobacco by Agrobacterium-mediated transformation. Both promoter fragments conferred elicitor-mediated expression in cell suspension cultures derived from transgenic plants of both species and fungal infection-mediated expression in leaves of transgenic alfalfa. Developmental expression directed by both promoter fragments in transgenic alfalfa was observed only in the root meristem, cortex, and nodules, which is consistent with the accumulation of endogenous IFR transcripts. However, in transgenic tobacco, expression from the 765-bp promoter was observed in vegetative tissues (root meristem and cortex, inner vascular tissue of stems and petioles, leaf tips, and stem peripheries adjacent to petioles) and in reproductive tissues (stigma, placenta, base of the ovary, receptacle, seed, tapetal layer, and pollen grains), whereas the 436-bp promoter was expressed only in fruits, seed, and pollen. These data indicate that infection/elicitor inducibility of the IFR promoter in both species and developmental expression in alfalfa are determined by sequences downstream of position -436, whereas sequences between -436 and -765 confer a complex pattern of strong ectopic developmental expression in the heterologous species that lacks the isoflavonoid pathway. PMID:7866024

  3. Sample Optimization for Five Plant-Parasitic Nematodes in an Alfalfa Field

    PubMed Central

    Goodell, P. B.; Ferris, H.

    1981-01-01

    A data base representing nematode counts and soil weight from 1,936 individual soil cores taken from a 7-ha alfalfa field was used to investigate sample optimization for five plant-parasitic nematodes: Meloidogyne arenaria, Pratylenchus minyus, Merlinius brevidens, Helicotylenchus digonicus, and Paratrichodorus minor. Sample plans were evaluated by the accuracy and reliability of their estimation of the population and by the cost of collecting, processing, and counting the samples. Interactive FORTRAN programs were constructed to simulate four collecting patterns: random; division of the field into square sub-units (cells); and division of the field into rectangular sub-traits (strips) running in two directions. Depending on the pattern, sample numbers varied from 1 to 25 with each sample representing from 1 to 50 cores. Each pattern, sample, and core combination was replicated 50 times. Strip stratification north/south was the most optimal sampling pattern in this field because it isolated a streak of fine-textured soil. The mathematical optimmn was not found because of data range limitations. When practical economic time constraints (5 hr to collect, process, and count nematode samples) are placed on the optimization process, all species estimates deviate no more than 25 % from the true mean. If accuracy constraints are placed on the process (no more than 15% deviation from true field mean), all species except Merlinius required less than 5 hr to complete the sample process. PMID:19300768

  4. Growth and photosynthetic responses of wheat plants grown in space.

    PubMed

    Tripathy, B C; Brown, C S; Levine, H G; Krikorian, A D

    1996-03-01

    Growth and photosynthesis of wheat (Triticum aestivum L. cv Super Dwarf) plants grown onboard the space shuttle Discovery for 10 d were examined. Compared to ground control plants, the shoot fresh weight of space-grown seedlings decreased by 25%. Postflight measurements of the O2 evolution/photosynthetic photon flux density response curves of leaf samples revealed that the CO2-saturated photosynthetic rate at saturating light intensities in space-grown plants declined 25% relative to the rate in ground control plants. The relative quantum yield of CO2-saturated photosynthetic O2 evolution measured at limiting light intensities was not significantly affected. In space-grown plants, the light compensation point of the leaves increased by 33%, which likely was due to an increase (27%) in leaf dark-respiration rates. Related experiments with thylakoids isolated from space-grown plants showed that the light-saturated photosynthetic electron transport rate from H2O through photosystems II and I was reduced by 28%. These results demonstrate that photosynthetic functions are affected by the microgravity environment.

  5. Growth and photosynthetic responses of wheat plants grown in space

    NASA Technical Reports Server (NTRS)

    Tripathy, B. C.; Brown, C. S.; Levine, H. G.; Krikorian, A. D.

    1996-01-01

    Growth and photosynthesis of wheat (Triticum aestivum L. cv Super Dwarf) plants grown onboard the space shuttle Discovery for 10 d were examined. Compared to ground control plants, the shoot fresh weight of space-grown seedlings decreased by 25%. Postflight measurements of the O2 evolution/photosynthetic photon flux density response curves of leaf samples revealed that the CO2-saturated photosynthetic rate at saturating light intensities in space-grown plants declined 25% relative to the rate in ground control plants. The relative quantum yield of CO2-saturated photosynthetic O2 evolution measured at limiting light intensities was not significantly affected. In space-grown plants, the light compensation point of the leaves increased by 33%, which likely was due to an increase (27%) in leaf dark-respiration rates. Related experiments with thylakoids isolated from space-grown plants showed that the light-saturated photosynthetic electron transport rate from H2O through photosystems II and I was reduced by 28%. These results demonstrate that photosynthetic functions are affected by the microgravity environment.

  6. Growth and photosynthetic responses of wheat plants grown in space.

    PubMed Central

    Tripathy, B C; Brown, C S; Levine, H G; Krikorian, A D

    1996-01-01

    Growth and photosynthesis of wheat (Triticum aestivum L. cv Super Dwarf) plants grown onboard the space shuttle Discovery for 10 d were examined. Compared to ground control plants, the shoot fresh weight of space-grown seedlings decreased by 25%. Postflight measurements of the O2 evolution/photosynthetic photon flux density response curves of leaf samples revealed that the CO2-saturated photosynthetic rate at saturating light intensities in space-grown plants declined 25% relative to the rate in ground control plants. The relative quantum yield of CO2-saturated photosynthetic O2 evolution measured at limiting light intensities was not significantly affected. In space-grown plants, the light compensation point of the leaves increased by 33%, which likely was due to an increase (27%) in leaf dark-respiration rates. Related experiments with thylakoids isolated from space-grown plants showed that the light-saturated photosynthetic electron transport rate from H2O through photosystems II and I was reduced by 28%. These results demonstrate that photosynthetic functions are affected by the microgravity environment. PMID:8819868

  7. Liquid chromatography-tandem mass spectrometry method for the determination of anthelmintics in alfalfa plants.

    PubMed

    Islam, M Dabalus; Haberhauer, G; Gerzabek, M; Cannavan, A

    2012-01-01

    A simple and inexpensive liquid chromatography-tandem mass spectrometric method for the determination of anthelmintics in alfalfa plants (Medicago sativa L.) was developed and validated. Anthelmintics in plant leaves and stems (green chops) were extracted with methanol/acetonitrile (7:3, v/v) followed by a concentration and clean-up step using solid-phase extraction (Strata-X, 500 mg, 6 ml cartridge). After drying with nitrogen gas, the adsorbed analytes were eluted with methanol/acetonitrile (50:50, v/v) mixture followed by 100% acetonitrile. Chromatographic separation was achieved on an Atlantis T-3 (2.1 × 100 mm × 3 µm) analytical column with a Phenomenex guard cartridge (C8, 4 × 3 mm) attached to a Waters triple quadrupole mass spectrometer operated in positive electrospray ionisation mode with selected reaction monitoring. Samples were analysed using gradient elution at a flow rate of 0.35 ml min⁻¹. The mobile phase consisted of a 10 mM ammonium formate solution in (A) water/acetonitrile (90:10, v/v) and (B) methanol/acetonitrile (50:50, v/v). The method was validated for levamisole, fenbendazole, fenbendazole sulphoxide and fenbendazole sulphone at 10, 20 and 40 µg kg⁻¹ and for eprinomectin at 20, 40 and 80 µg kg⁻¹. Limits of quantification (LOQ) were 10 µg kg⁻¹ for all analytes except eprinomectin, which had an LOQ of 20 µg kg⁻¹. The overall mean recovery in green plants was between 74.2% and 81.4% with repeatabilities ranging from 2.2% to 19.1% and reproducibilities in the range 3.8-8.7%. The validated method was applied to plant samples in a study on the behaviour of anthelmintic drugs in a soil, plant and water system.

  8. [ITS-polymorphism of salt-tolerant and salt-sensitive native isolates of Sinorhizoblum meliloti--symbionts of alfalfa, clover and fenugreek plants].

    PubMed

    Rumiantseva, M L; Muntian, V S; Mengoni, A; Simarov, B V

    2014-04-01

    Polymorphism of rrs-rrl sequence of ribosomal operons (intergenic sequence, ITS) was studied among 81 isolates of Sinorhizobium meliloti (AK001-AK210) derived from the collection of alfalfa nodulating bacteria of the Laboratory of genetics of ARRIAM, by using species-specific primers FGPS 1490/FGPL132VM. Isolates were obtained from nodules of different species of wild host plants from Medicago, Melilotus and Trigonella genera grown in salinized North-Western region of Kazakhstan. The typical structure of ITS, similar to that of test strain Rm1021, was dominant in native rhizobia population, while in one third of the isolates (33.3%) this sequence was divergent. Among the latter, the ITS type of strain AK83 (RCAM00182) was dominant. Here, we show for the first time that isolates with reduced level of salt-tolerance had more diverse intergenic sequences of rrn-operons. No phylogenetic separation was observed between isolates grouped on the basis of their tolerance or sensitivity towards 0.6 M NaCl. However, the frequency of divergent ITS types within the two groups of rhizobia depended on the host symbiotic preference observed in natural environment, allowing to speculate about the existence of a chromosome types specific for S. meliloti isolates with differential salt tolerance. In conclusion, we propose that in the area subjected to secondary salinization, which are also the centre of introgressive hybridization of alfalfa, micro-evolutionary processes, affecting rrn-operons and associated with salt adaptation, are also occurring in symbiotic root nodule bacteria populations.

  9. Co-expression of tonoplast Cation/H(+) antiporter and H(+)-pyrophosphatase from xerophyte Zygophyllum xanthoxylum improves alfalfa plant growth under salinity, drought and field conditions.

    PubMed

    Bao, Ai-Ke; Du, Bao-Qiang; Touil, Leila; Kang, Peng; Wang, Qiang-Long; Wang, Suo-Min

    2016-03-01

    Salinity and drought are major environmental factors limiting the growth and productivity of alfalfa worldwide as this economically important legume forage is sensitive to these kinds of abiotic stress. In this study, transgenic alfalfa lines expressing both tonoplast NXH and H(+)-PPase genes, ZxNHX and ZxVP1-1 from the xerophyte Zygophyllum xanthoxylum L., were produced via Agrobacterium tumefaciens-mediated transformation. Compared with wild-type (WT) plants, transgenic alfalfa plants co-expressing ZxNHX and ZxVP1-1 grew better with greater plant height and dry mass under normal or stress conditions (NaCl or water-deficit) in the greenhouse. The growth performance of transgenic alfalfa plants was associated with more Na(+), K(+) and Ca(2+) accumulation in leaves and roots, as a result of co-expression of ZxNHX and ZxVP1-1. Cation accumulation contributed to maintaining intracellular ions homoeostasis and osmoregulation of plants and thus conferred higher leaf relative water content and greater photosynthesis capacity in transgenic plants compared to WT when subjected to NaCl or water-deficit stress. Furthermore, the transgenic alfalfa co-expressing ZxNHX and ZxVP1-1 also grew faster than WT plants under field conditions, and most importantly, exhibited enhanced photosynthesis capacity by maintaining higher net photosynthetic rate, stomatal conductance, and water-use efficiency than WT plants. Our results indicate that co-expression of tonoplast NHX and H(+)-PPase genes from a xerophyte significantly improved the growth of alfalfa, and enhanced its tolerance to high salinity and drought. This study laid a solid basis for reclaiming and restoring saline and arid marginal lands as well as improving forage yield in northern China.

  10. The Pattern of Secreted Molecules During the Co-Inoculation of Alfalfa Plants With Sinorhizobium meliloti and Delftia sp. strain JD2: An Interaction That Improves Plant Yield.

    PubMed

    Morel, M A; Cagide, C; Minteguiaga, M A; Dardanelli, M S; Castro-Sowinski, S

    2015-02-01

    Delftia sp. strain JD2 is a plant-growth-promoting bacterium that enhances legume nodulation and growth, acting as nodule-assisting bacterium during the co-inoculation of plants with rhizobial strains. In this work, we evaluate how the co-inoculation of alfalfa with Sinorhizobium meliloti U143 and JD2 increases plant yield under greenhouse conditions and we analyze the pattern of secreted bioactive compounds which may be involved in the microbe-plant communication. The chemical composition of extracellular cultures (EC) produced in hydroponic conditions (collected 4, 7, and 14 days after bacterial treatment) were characterized using different chromatographic and elucidation techniques. In addition, we assessed the effect that plant irrigation with cell-free EC, produced during co-inoculation experiments, would have on plant yield. Results showed increased alfalfa shoot and root matter, suggesting that U143-JD2 co-inoculation might be a beneficial agricultural practice. The pattern of secreted secondary metabolites among treatments showed important differences. Qualitative and quantitative changes in phenolic compounds (including flavonoids), organic acids, and volatile compounds were detected during the early microbe-plant interaction, suggesting that the production of some molecules positively affects the microbe-plant association. Finally, the irrigation of co-inoculated plants with cell-free EC under greenhouse conditions increased plant yield over agronomic expectations. This effect might be attributed to the bioactive secondary metabolites incorporated during the irrigation.

  11. Scientists Inspect Plant Grown onboard the ISS in 2002

    NASA Technical Reports Server (NTRS)

    2003-01-01

    The Advanced Astroculture (tm) unit is growing plants on its second flight on the International Space Station. Dr. Weijia Zhou (left), director of the Wisconsin Center for Space Automation and Robotics at the University of Wisconsin-Madison, inspects soybeans grown in the plant growth unit aboard ISS in 2002. Coating technology is used inside the miniature plant greenhouse to remove ethylene, a chemical produced by plant leaves that can cause plants to mature too quickly. This same coating technology is used in a new anthrax-killing device. The Space Station experiment is managed by the Space Partnership Development Program at NASA's Marshall Space Flight Center in Huntsville, Ala.

  12. Effects of nitrogen source and water availability on stem carbohydrates and cellulosic bioethanol traits of alfalfa plants.

    PubMed

    Fiasconaro, M Laura; Gogorcena, Yolanda; Muñoz, Fernando; Andueza, Donato; Sánchez-Díaz, Manuel; Antolín, M Carmen

    2012-08-01

    Symbiotic association of legumes with rhizobia frequently results in higher photosynthesis and soluble carbohydrates in comparison with nitrate-fed plants, which might improve its potential for biomass conversion into bioethanol. A greenhouse experiment was conducted to examine the effects of nitrogen source and water availability on stem characteristics and on relationships between carbohydrates, phenolic metabolism activity and cell wall composition in alfalfa (Medicago sativa L. cv. Aragón). The experiment included three treatments: (1) plants fed with ammonium nitrate (AN); (2) plants inoculated with rhizobia (R); and (3) plants inoculated with rhizobia and amended with sewage sludge (RS). Two levels of irrigation were imposed: (1) well-watered and (2) drought stress. Under well-watered conditions, nitrogen-fixing plants have increased photosynthesis and stem fermentable carbohydrate concentrations, which result in higher potential for biomass conversion to bioethanol than in AN plants. The latter had higher lignin due to enhanced activities of phenolic metabolism-related enzymes. Under drought conditions, the potential for bioethanol conversion decreased to a similar level in all treatments. Drought-stressed nitrogen-fixing plants have high concentrations of fermentable carbohydrates and cell wall cellulose, but ammonium nitrate-fed plants produced higher plant and stem biomass, which might compensate the decreasing stem carbohydrates and cellulose concentrations.

  13. Lipo-chitooligosaccharide Nodulation Signals from Rhizobium meliloti Induce Their Rapid Degradation by the Host Plant Alfalfa.

    PubMed Central

    Staehelin, C.; Schultze, M.; Kondorosi, E.; Kondorosi, A.

    1995-01-01

    Extracellular enzymes from alfalfa (Medicago sativa L.) involved in the degradation of nodulation (Nod) factors could be distinguished by their different cleavage specificities and were separated by lectin affinity chromatography. A particular glycoprotein was able to release an acylated lipo-disaccharide from all tested Nod factors having an oligosaccharide chain length of four or five residues. Structural modifications of the basic lipo-chitooligosaccharide did not affect the cleavage site and had only weak influence on the cleavage efficiency of Nod factors tested. The acylated lipo-trisaccharide was resistant to degradation. When alfalfa roots were preincubated with Nod factors at nanomolar concentrations, the activity of the dimer-forming enzyme was stimulated up to 6-fold within a few hours. The inducing activity of Nod factors decreased in the order NodRm-IV(C16:2,Ac,S) > NodRm-IV(C16:2,S) and NodRm-V(C16:2,Ac,S) > NodRm-V(C16:2,S) > NodRm-IV(C16:0,S) > NodRm-IV(C16:2). Pretreatment with NodRm-III(C16:2) as well as unmodified chitooligosaccharides did not stimulate the dimer-forming enzyme. Roots preincubated with Rhizobium meliloti showed similar stimulation of the dimer-forming activity. Mutant strains unable to produce Nod factors did not enhance the hydrolytic activity. These results indicate a rapid feedback inactivation of Nod signals after their perception by the host plant alfalfa. PMID:12228566

  14. Accumulation of seleno-amino acids in legume and grass plant species grown in selenium-laden soils

    SciTech Connect

    Wu, L.; Guo, X.; Banuelos, G.S.

    1997-03-01

    Seleno-amino acid accumulation was studied for two legume and two grass species grown in Selenium (Se)-laden soils. An antagonistic relationship was found between the tissue Se-amino acid concentration and the corresponding sulfur-amino acid concentration. This relationship demonstrates a competitive interaction between Se and sulfate at the amino acid synthesis level. The nonsulfur-containing amino acids were not substantially affected by the increase of tissue Se concentration. Sour clover (Melilotus indica L.) was able to accumulate much greater tissue Se concentration than the other three species. Tissue methionine concentration of sour clover, rabbitfoot grass (Polypogon monspeliensis L.), and tall fescue (Festuca arundinacea Schreb.) was not significantly affected by the increase of tissue selenomethionine concentration, but a highly significant negative correlation was found in alfalfa (Medicago sativa L.). This discrepancy suggests that a less antagonistic effect on sulfur-amino acids under the increase of Se-amino acid analogues in the tissue might be able to minimize Se toxicity to the plant. Both Se-methylselenocysteine (nonprotein amino acid) and selenomethionine (protein amino acid) accumulated in the plants when grown in Se-laden soils. Possible effects of these Se-amino acids accumulated by plants on animal health should be tested before the plants are used for forage supplementation.

  15. Characterization of Pseudomonas species isolated from the rhizosphere of plants grown in serozem soil, semi arid region of Uzbekistan.

    PubMed

    Egamberdiyeva, Dilfuza

    2005-07-08

    Collections of native Pseudomonas spp. are kept at the NCAM of Uzbekistan. Some of those organisms were isolated from the rhizosphere of cotton, wheat, corn, melon, alfalfa, and tomato grown in field locations within a semi-arid region of Uzbekistan. Strains used for this study were Pseudomonas alcaligenes, P. aurantiaca, P. aureofaciens, P. denitrificans, P. mendocina, P. rathonis, and P. stutzeri. Some of the pseudomonads have been characterized in this report. These strains produced enzymes, phytohormone auxin (IAA), and were antagonist against plant pathogenic fungi in in vitro experiments. Most of the strains were salt tolerant and temperature resistant. Some of the Pseudomonas spp. isolated in this study have been found to increase the growth of wheat, corn, and tomato in pot experiments.

  16. Influence of Mount St. Helens volcanic ash on alfalfa growth and nutrient uptake

    SciTech Connect

    Mahler, R.L.

    1984-01-01

    Concern has been expressed that large amounts of volcanic ash from the May 18, 1980 eruption of Mount St. Helens may have created potential nutritional problems associated with forage production in northern Idaho and eastern Washington to the extent that adjustments need to be made in soil test correlation data. The objectives of this greenhouse study were to : (1) determine the effect of varying amounts of volcanic ash mixed into soils of northern Idaho on total alfalfa biomass production, and (2) to determine the effect of various soil/ash mixtures on the nutrient concentrations of P, K, S, Ca, Mg, Mn and Zn in alfalfa. Alfalfa was grown in eight different northern Idaho soils amended with differing levels of volcanic ash (0, 20, 35, 50 and 75%) in the greenhouse. The alfalfa seeds were inoculated and fertilizer P and S were added to all treatments. Total plant biomass and P, K, S, Ca, Mg, Mn and Zn plant concentrations were measured. The eight were pooled for analysis and it was found that increasing amounts of volcanic ash increased alfalfa biomass production. Plant P, S, Ca, Mg and Zn concentrations also increased with increasing levels of ash. Conversely, increasing levels of ash resulted in lower alfalfa tissue K and Mn concentrations. 13 references, 7 figures.

  17. Lignin modification leads to increased nodule numbers in alfalfa.

    PubMed

    Gallego-Giraldo, Lina; Bhattarai, Kishor; Pislariu, Catalina I; Nakashima, Jin; Jikumaru, Yusuke; Kamiya, Yuji; Udvardi, Michael K; Monteros, Maria J; Dixon, Richard A

    2014-03-01

    Reduction of lignin levels in the forage legume alfalfa (Medicago sativa) by down-regulation of the monolignol biosynthetic enzyme hydroxycinnamoyl coenzyme A:shikimate hydroxycinnamoyl transferase (HCT) results in strongly increased digestibility and processing ability of lignocellulose. However, these modifications are often also associated with dwarfing and other changes in plant growth. Given the importance of nitrogen fixation for legume growth, we evaluated the impact of constitutively targeted lignin modification on the belowground organs (roots and nodules) of alfalfa plants. HCT down-regulated alfalfa plants exhibit a striking reduction in root growth accompanied by an unexpected increase in nodule numbers when grown in the greenhouse or in the field. This phenotype is associated with increased levels of gibberellins and certain flavonoid compounds in roots. Although HCT down-regulation reduced biomass yields in both the greenhouse and field experiments, the impact on the allocation of nitrogen to shoots or roots was minimal. It is unlikely, therefore, that the altered growth phenotype of reduced-lignin alfalfa is a direct result of changes in nodulation or nitrogen fixation efficiency. Furthermore, HCT down-regulation has no measurable effect on carbon allocation to roots in either greenhouse or 3-year field trials.

  18. Specific mechanisms of tolerance to copper and cadmium are compromised by a limited concentration of glutathione in alfalfa plants.

    PubMed

    Flores-Cáceres, María Laura; Hattab, Sabrine; Hattab, Sarra; Boussetta, Hamadi; Banni, Mohammed; Hernández, Luis E

    2015-04-01

    The induction of oxidative stress is a characteristic symptom of metal phytotoxicity and is counteracted by antioxidants such as glutathione (GSH) or homoglutathione (hGSH). The depletion of GSH│hGSH in fifteen-day-old alfalfa (Medicago sativa) plants pre-incubated with 1mM buthionine sulfoximine (BSO) affected antioxidant responses in a metal-specific manner under exposure to copper (Cu; 0, 6, 30 and 100μM) or cadmium (Cd; 0, 6 and 30μM) for 7 days. The phytotoxic symptoms observed with excess Cu were accompanied by an inhibition of root glutathione reductase (GR) activity, a response that was augmented in Cd-treated plants but reverted when combined with BSO. The synthesis of phytochelatins (PCs) was induced by Cd, whereas the biothiol concentration decreased in Cu-treated plants, which did not accumulate PCs. The depletion of GSH│hGSH by BSO also produced a strong induction of oxidative stress under excess Cu stress, primarily due to impaired GSH│hGSH-dependent redox homeostasis. In addition, the synthesis of PCs was required for Cd detoxification, apparently also determining the distribution of Cd in plants, as less metal was translocated to the shoots in BSO-incubated plants. Therefore, specific GSH│hGSH-associated mechanisms of tolerance were triggered by stress due to each metal.

  19. Influence of plant ontogeny and abiotic factors on resistance of glandular-haired alfalfa to potato leafhopper (Hemiptera: Cicadellidae).

    PubMed

    Casteel, Clare L; Ranger, Christopher M; Backus, Elaine A; Ellersieck, Mark R; Johnson, David W

    2006-04-01

    Laboratory experiments were conducted to characterize the trichome-based defense of glandular-haired alfalfa, Medicago sativa L., against the potato leafhopper, Empoasca fabae (Harris). Within-plant variability in leafhopper resistance was examined by caging adult leafhoppers to either basal or apical stem internodes of the leafhopper-resistant, glandular-haired M. sativa genotype G98A or the susceptible, nonglandular-haired M. sativa 'Ranger'. Young, actively secreting glandular trichomes are located on apical internodes of G98A, whereas senesced gland heads are found on older, basal internodes of G98A. After 96 h, the highest cumulative leafhopper mortality and lowest number of excretory droplets were associated with apical internodes of G98A. No difference was detected in mortality and feeding levels among insects caged to basal internodes of G98A and basal and apical internodes of Ranger. The influence of abiotic factors on leafhopper resistance was evaluated by caging adult leafhoppers to either G98A or Ranger under four combinations of low and high light (250 and 1,000 micromol s(-1) m(-2)) and temperature regimes (17 and 30 degrees C). After 96 h, the highest cumulative mortality was associated with leafhoppers confined to G98A under high light and high temperature conditions. Temperature level and plant type also had an effect on the production of excretory droplets, resulting in the highest number of excretory droplets being associated with Ranger under the high temperature regime. These results indicate that certain regions of M. sativa G98A are better protected against the potato leafhopper than others and that temperature influences resistance levels of glandular-haired alfalfa.

  20. Water and phosphorus content affect PAH dissipation in spiked soil planted with mycorrhizal alfalfa and tall fescue.

    PubMed

    Zhou, X B; Cébron, A; Béguiristain, T; Leyval, C

    2009-10-01

    Polycyclic aromatic hydrocarbon (PAH) dissipation efficiency can be increased in the plant rhizosphere, but may be affected by various environmental factors. We investigated the effects of the watering regime and phosphorus concentration on PAH dissipation in the rhizosphere of mycorrhizal plants in a pot experiment. Two plant species, alfalfa (Medicago sativa) and tall fescue (Festuca arundinacea), were co-cultured and inoculated with an arbuscular mycorrhizal (AM) fungus (Glomus intraradices) in PAH (phenanthrene (PHE)=500 mg kg(-1), pyrene (PYR)=500 mg kg(-1), dibenzo(a,h)anthracene (DBA)=65 mg kg(-1)) spiked agricultural soil for 6 weeks. Treatments with different phosphorus concentrations and watering regimes were compared. The PHE dissipation reached 90% in all treatments and was not affected by the treatments. The major finding was the significant positive impact of mycorrhizal plants on the dissipation of high molecular weight PAH (DBA) in high-water low-phosphorus treatment. Such an effect was not observed in high-water high-phosphorus and low-water low-phosphorus treatments, where AM colonization was very low. A positive linear relationship was detected between PYR dissipation and the percentage of Gram-positive PAH-ring hydroxylating dioxygenase genes in high-water high-phosphorus treatments, but not in the other two treatments with lower phosphorus concentrations and water contents. Such results indicated that the phosphorus and water regime were important parameters for the dissipation of HMW-PAH.

  1. The succinoglycan endoglycanase encoded by exoK is required for efficient symbiosis of Sinorhizobium meliloti 1021 with the host plants Medicago truncatula and Medicago sativa (Alfalfa).

    PubMed

    Mendis, Hajeewaka C; Queiroux, Clothilde; Brewer, Tess E; Davis, Olivia M; Washburn, Brian K; Jones, Kathryn M

    2013-09-01

    The acidic polysaccharide succinoglycan produced by the nitrogen-fixing rhizobial symbiont Sinorhizobium meliloti 1021 is required for this bacterium to invade the host plant Medicago truncatula and to efficiently invade the host plant M. sativa (alfalfa). The β-glucanase enzyme encoded by exoK has previously been demonstrated to cleave succinoglycan and participate in producing the low molecular weight form of this polysaccharide. Here, we show that exoK is required for efficient S. meliloti invasion of both M. truncatula and alfalfa. Deletion mutants of exoK have a substantial reduction in symbiotic productivity on both of these plant hosts. Insertion mutants of exoK have an even less productive symbiosis than the deletion mutants with the host M. truncatula that is caused by a secondary effect of the insertion itself, and may be due to a polar effect on the expression of the downstream exoLAMON genes.

  2. Plant response to heavy metal toxicity: comparative study between the hyperaccumulator Thlaspi caerulescens (ecotype Ganges) and nonaccumulator plants: lettuce, radish, and alfalfa.

    PubMed

    Benzarti, Saoussen; Mohri, Shino; Ono, Yoshiro

    2008-10-01

    Thlaspi caerulescens (alpine pennycress) is one of the best-known heavy metal (HM) hyperaccumulating plant species. It exhibits the ability to extract and accumulate various HM at extremely high concentrations. In this hydroponic study, the performance of T. caerulescens (ecotype Ganges) to accumulate Cd, Zn, and Cu was compared with that of three nonaccumulator plants: alfalfa (Medicago sativa), radish (Raphanus sativus), and lettuce (Lactuca sativa). Plants were exposed to the separately dissolved HM salts for 7 days at a wide range of increasing concentrations: 0 (control: 1/5 Hoagland nutrient solution), 0.1, 1, 10, 100, and 1000 microM. The comparative study combined chemical, physiological, and ecotoxicological assessments. Excessive concentrations of HM (100 and 1000 microM) affected plant growth, photosynthesis, and phytoaccumulation efficiency. Root exudation for all plant species was highly and significantly correlated to HM concentration in exposure solutions and proved its importance to counter effect toxicity. T. caerulescens resisted better the phytotoxic effects of Cd and Zn (at 1000 microM each), and translocated them significantly within tissues (366 and 1290 microg g(-1), respectively). At the same HM level, T. caerulescens exhibited lower performances in accumulating Cu when compared with the rest of plant species, mainly alfalfa (298 microg g(-1)). Root elongation inhibition test confirmed the selective aptitude of T. caerulescens to better cope with Cd and Zn toxicities. MetPLATE bioassay showed greater sensitivity to HM toxicity with much lower EC(50) values for beta-galactosidase activity in E. coli. Nevertheless, exaggerated HM concentrations coupled with relatively short exposure time did not allow for an efficient metal phytoextraction thus a significant reduction of ecotoxicity.

  3. Expression of an alfalfa (Medicago sativa L.) ethylene response factor gene MsERF8 in tobacco plants enhances resistance to salinity.

    PubMed

    Chen, Tingting; Yang, Qingchuan; Gruber, Margaret; Kang, Junmei; Sun, Yan; Ding, Wang; Zhang, Tiejun; Zhang, Xinquan

    2012-05-01

    Ethylene response factors (ERF) play crucial roles in plant development and response to stresses. Here, a novel cDNA fragment (MsERF8) encoding an ERF protein with an AP2 domain was isolated and characterized from alfalfa. The MsERF8 cDNA has an open reading frame of 603 bp and encodes a nuclear protein of 201 amino acids. Q-RT-PCR analysis revealed that MsERF8 was strongly enriched in roots and leaves compared with stems, flower buds and flowers of mature alfalfa plants. Bioinformatic analysis of the MsERF8 promoter indicated a number of elements associated with stress-related responses, and MsERF8 transcripts in alfalfa seedlings were induced by NaCl, PEG6000, Al(2)(SO(4))(3) and five different hormones. Expression of MsERF8 in transgenic tobacco plants resulted in higher tolerance to salinity than with non-transgenic plants. This data shows that MsERF8 is a gene which prevents or alleviates salinity damage and has strong potential to impart salt tolerance to other crop plants.

  4. Some karyological observations on plants grown in space

    NASA Technical Reports Server (NTRS)

    Krikorian, A. D.; Oconnor, S. A.

    1982-01-01

    Experiments were conducted to assess whether cell division in a plant root would be affected by prolonged exposure to microgravity. Root materials from sunflower, oat, and mung bean plants grown on STS-2 and STS-3 were utilized for the experiments. It is found that all oat, sunflower, and mung seedlings showed a reduced number of cells in division as they went through their first cell division cycle on earth when compared to their ground controls. A significant number of oat, mung, and sunflower plantlets exhibited random root orientation and the lack of strictly orthotropic growth of their shoot systems in the flight samples. In addition, it is found that the mung roots were apparently least affected in terms of their cytology despite the fact that their roots were often randomly oriented.

  5. Cogeneration for existing alfalfa processing

    SciTech Connect

    Not Available

    1984-01-01

    This study is designed to look at the application of gas-turbine generator cogeneration to a typical Nebraska alfalfa processing mill. The practicality is examined of installing a combustion turbine generator at a plant site and modifying existing facilities for generating electricity, utilizing the electricity generated, selling excess electricity to the power company and incorporating the turbine exhaust flow as a drying medium for the alfalfa. The results of this study are not conclusive but the findings are summarized.

  6. Functional Characterizations of Chemosensory Proteins of the Alfalfa Plant Bug Adelphocoris lineolatus Indicate Their Involvement in Host Recognition

    PubMed Central

    Zhang, Xue-Ying; Ji, Ping; Liu, Jing-Tao; Wang, Gui-Rong; Wu, Kong-Ming; Guo, Yu-Yuan; Zhou, Jing-Jiang; Zhang, Yong-Jun

    2012-01-01

    Insect chemosensory proteins (CSPs) have been proposed to capture and transport hydrophobic chemicals from air to olfactory receptors in the lymph of antennal chemosensilla. They may represent a new class of soluble carrier protein involved in insect chemoreception. However, their specific functional roles in insect chemoreception have not been fully elucidated. In this study, we report for the first time three novel CSP genes (AlinCSP1-3) of the alfalfa plant bug Adelphocoris lineolatus (Goeze) by screening the antennal cDNA library. The qRT-PCR examinations of the transcript levels revealed that all three genes (AlinCSP1-3) are mainly expressed in the antennae. Interestingly, these CSP genes AlinCSP1-3 are also highly expressed in the 5th instar nymphs, suggesting a proposed function of these CSP proteins (AlinCSP1-3) in the olfactory reception and in maintaining particular life activities into the adult stage. Using bacterial expression system, the three CSP proteins were expressed and purified. For the first time we characterized the types of sensilla in the antennae of the plant bug using scanning electron microscopy (SEM). Immunocytochemistry analysis indicated that the CSP proteins were expressed in the pheromone-sensitive sensilla trichodea and general odorant-sensitive sensilla basiconica, providing further evidence of their involvement in chemoreception. The antennal activity of 55 host-related semiochemicals and sex pheromone compounds in the host location and mate selection behavior of A. lineolatus was investigated using electroantennogram (EAG), and the binding affinities of these chemicals to the three CSPs (AlinCSP1-3) were measured using fluorescent binding assays. The results showed several host-related semiochemicals, (Z)-3-hexen-1-ol, (E)-2-hexen-1-al and valeraldehyde, have a high binding affinity with AlinCSP1-3 and can elicit significant high EAG responses of A. lineolatus antennae. Our studies indicate the three antennae-biased CSPs may

  7. [Determination of Hard Rate of Alfalfa (Medicago sativa L.) Seeds with Near Infrared Spectroscopy].

    PubMed

    Wang, Xin-xun; Chen, Ling-ling; Zhang, Yun-wei; Mao, Pei-sheng

    2016-03-01

    Alfalfa (Medicago sativa L.) is the most commonly grown forage crop due to its better quality characteristics and high adaptability in China. However, there was 20%-80% hard seeds in alfalfa which could not be identified easily from non hard seeds which would cause the loss of seed utilization value and plant production. This experiment was designed for 121 samples of alfalfa. Seeds were collected according to different regions, harvested year and varieties. 31 samples were artificial matched as hard rates ranging from 20% to 80% to establish a model for hard seed rate by near infrared spectroscopy (NIRS) with Partial Least Square (PLS). The objective of this study was to establish a model and to estimate the efficiency of NIRS for determining hard rate of alfalfa seeds. The results showed that the correlation coefficient (R2(cal)) of calibration model was 0.981 6, root mean square error of cross validation (RMSECV) was 5.32, and the ratio of prediction to deviation (RPD) was 3.58. The forecast model in this experiment presented the satisfied precision. The proposed method using NIRS technology is feasible for identification and classification of hard seed in alfalfa. A new method, as nondestructive testing of hard seed rate, was provided to theoretical basis for fast nondestructive detection of hard seed rates in alfalfa.

  8. Gene expression in Fusarium graminearum grown on plant cell wall.

    PubMed

    Carapito, Raphaël; Hatsch, Didier; Vorwerk, Sonja; Petkovski, Elizabet; Jeltsch, Jean-Marc; Phalip, Vincent

    2008-05-01

    Fusarium graminearum is a phytopathogenic filamentous fungus attacking a wide range of plants including Humulus lupulus (hop). Transcriptional analysis of F. graminearum grown on minimal media containing hop cell wall or glucose as the sole carbon source was performed by applying a highly stringent method combining microarrays and a subtracted cDNA library. In addition to genes coding for various cell wall degrading enzymes (CWDE), several metabolic pathways were induced in response to the plant cell wall substrate. Many genes participating in these pathways are probably involved in cellular transport. But the most interesting was that all the genes composing the 4-aminobutyrate-shunt (GABA-shunt) were also up-regulated in the presence of plant cell wall material and were present in the cDNA library. This study provides a description of a part of the fungal gene expression profile when it is in contact with raw biological materials, and helps in understanding the plant cell wall degradation and the infection process.

  9. Complete genome sequence and integrated protein localization and interaction map for alfalfa dwarf virus, which combines properties of both cytoplasmic and nuclear plant rhabdoviruses

    SciTech Connect

    Bejerman, Nicolás; Giolitti, Fabián; Breuil, Soledad de; Trucco, Verónica; Nome, Claudia; Lenardon, Sergio; Dietzgen, Ralf G.

    2015-09-15

    Summary: We have determined the full-length 14,491-nucleotide genome sequence of a new plant rhabdovirus, alfalfa dwarf virus (ADV). Seven open reading frames (ORFs) were identified in the antigenomic orientation of the negative-sense, single-stranded viral RNA, in the order 3′-N-P-P3-M-G-P6-L-5′. The ORFs are separated by conserved intergenic regions and the genome coding region is flanked by complementary 3′ leader and 5′ trailer sequences. Phylogenetic analysis of the nucleoprotein amino acid sequence indicated that this alfalfa-infecting rhabdovirus is related to viruses in the genus Cytorhabdovirus. When transiently expressed as GFP fusions in Nicotiana benthamiana leaves, most ADV proteins accumulated in the cell periphery, but unexpectedly P protein was localized exclusively in the nucleus. ADV P protein was shown to have a homotypic, and heterotypic nuclear interactions with N, P3 and M proteins by bimolecular fluorescence complementation. ADV appears unique in that it combines properties of both cytoplasmic and nuclear plant rhabdoviruses. - Highlights: • The complete genome of alfalfa dwarf virus is obtained. • An integrated localization and interaction map for ADV is determined. • ADV has a genome sequence similarity and evolutionary links with cytorhabdoviruses. • ADV protein localization and interaction data show an association with the nucleus. • ADV combines properties of both cytoplasmic and nuclear plant rhabdoviruses.

  10. Overexpression of EsMcsu1 from the halophytic plant Eutrema salsugineum promotes abscisic acid biosynthesis and increases drought resistance in alfalfa (Medicago sativa L.).

    PubMed

    Zhou, C; Ma, Z Y; Zhu, L; Guo, J S; Zhu, J; Wang, J F

    2015-12-17

    The stress phytohormone abscisic acid (ABA) plays pivotal roles in plants' adaptive responses to adverse environments. Molybdenum cofactor sulfurases influence aldehyde oxidase activity and ABA biosynthesis. In this study, we isolated a novel EsMcsu1 gene encoding a molybdenum cofactor sulfurase from Eutrema salsugineum. EsMcus1 transcriptional patterns varied between organs, and its expression was significantly upregulated by abiotic stress or ABA treatment. Alfalfa plants that overexpressed EsMcsu1 had a higher ABA content than wild-type (WT) plants under drought stress conditions. Furthermore, levels of reactive oxygen species (ROS), ion leakage, and malondialdehyde were lower in the transgenic plants than in the WT plants after drought treatment, suggesting that the transgenic plants experienced less ROS-mediated damage. However, the expression of several stress-responsive genes, antioxidant enzyme activity, and osmolyte (proline and total soluble sugar) levels in the transgenic plants were higher than those in the WT plants after drought treatment. Therefore, EsMcsu1 overexpression improved drought tolerance in alfalfa plants by activating a series of ABA-mediated stress responses.

  11. Gene expression from plants grown on the International Space Station

    NASA Astrophysics Data System (ADS)

    Stimpson, Alexander; Pereira, Rhea; Kiss, John Z.; Correll, Melanie

    Three experiments were performed on the International Space Station (ISS) in 2006 as part of the TROPI experiments. These experiments were performed to study graviTROPIsm and photoTROPIsm responses of Arabidopsis in microgravity (µg). Seedlings were grown with a variety of light and gravitational treatments for approximately five days. The frozen samples were returned to Earth during three space shuttle missions in 2007 and stored at -80° C. Due to the limited amount of plant biomass returned, new protocols were developed to minimize the amount of material needed for RNA extraction as a preparation for microarray analysis. Using these new protocols, RNA was extracted from several sets of seedlings grown in red light followed by blue light with one sample from 1.0g treatment and the other at µg. Using a 2-fold change criterion, microarray (Affymetrix, GeneChip) results showed that 613 genes were upregulated in the µg sample while 757 genes were downregulated. Upregulated genes in response to µg included transcription factors from the WRKY (15 genes), MYB (3) and ZF (8) families as well as those that are involved in auxin responses (10). Downregulated genes also included transcription factors such as MYB (5) and Zinc finger (10) but interestingly only two WRKY family genes were down-regulated during the µg treatment. Studies are underway to compare these results with other samples to identify the genes involved in the gravity and light signal transduction pathways (this project is Supported By: NASA NCC2-1200).

  12. Herbivore responses to plants grown in enriched carbon dioxide atmospheres

    SciTech Connect

    Lincoln, D.E.

    1990-05-01

    Our initial study of sagebrush and grasshopper responses to elevated and historical carbon dioxide atmospheres is complete and has been accepted for publication. The study on Biomass Allocation Patterns of Defoliated Sagebrush Grown Under Two Levels of Carbon Dioxide has completed and the manuscript has been submitted for publication. We have completed the study of plant growth under two nutrient and carbon dioxide regimes and grasshopper feeding responses. The study of a specialist feeding caterpillar, the cabbage butterfly, and a mustard hostplant has recently been completed. We were able to identify the principal allelochemicals of the mustard plants, butenyl and pentenyl isothiocyanates, by combined gas chromatography and mass spectrometry. Measurement of these chemicals has been a critical component of this study since these compounds contain nitrogen and sulphur and act as a feeding stimulant to the caterpillar. This insect responds to elevated carbon dioxide by consuming more leaves and we can now say that this is not due to a change in the feeding stimulants. Reduced leaf protein content is a critical factor for even specialist feeding insect herbivores under elevated carbon dioxide conditions. The study on Grasshopper Population Responses to Enriched Carbon Dioxide Concentration is currently in progress at the Duke University Phytotron. We have changed hostplant species in order to complement the investigations of carbon dioxide effects on tallgrass prairie. Specifically, we are using big bluestem, Andropogon geradii, as the host plant to feed to the grasshoppers. This experiment will be completed in July 1990.

  13. Genetic Engineering of Alfalfa (Medicago sativa L.).

    PubMed

    Wang, Dan; Khurshid, Muhammad; Sun, Zhan Min; Tang, Yi Xiong; Zhou, Mei Liang; Wu, Yan Min

    2016-01-01

    Alfalfa is excellent perennial legume forage for its extensive ecological adaptability, high nutrition value, palatability and biological nitrogen fixation. It plays a very important role in the agriculture, animal husbandry and ecological construction. It is cultivated in all continents. With the development of modern plant breeding and genetic engineering techniques, a large amount of work has been carried out on alfalfa. Here we summarize the recent research advances in genetic engineering of alfalfa breeding, including transformation, quality improvement, stress resistance and as a bioreactor. The review article can enables us to understand the research method, direction and achievements of genetic engineering technology of Alfalfa.

  14. Effect of Mulch Surface Color on Root-knot of Tomato Grown in Simulated Planting Beds.

    PubMed

    Fortnum, B A; Kasperbauer, M J; Decoteau, D R

    2000-03-01

    The effect of different-colored polyethylene mulches on quantity and spectra of reflected light, plant morphology, and root-knot disease was studied in tomato (Lycopersicon esculentum) grown in simulated planting beds. Tomato plants were inoculated with Meloidogyne incognita at initial populations (Pi) of 0, 1,000, 10,000, or 50,000 eggs/plant, and grown in a greenhouse for 50 days over white, red, or black mulch. Soil temperature was kept constant among the mulch treatments by placing an insulation barrier between the colored mulch and the soil surface. Soil temperature varied less than 0.5 degrees C between soil chambers at solar noon. Tomatoes grown over white mulch received more reflected photosynthetic light and had greater shoot weights (27%), root weights (32%), and leaf area (20%) than plants grown over black mulch. Plants grown over red mulch received a higher far-red-to-red ratio in the reflected light. Mulch color altered the plant's response to root-knot nematode infection by changing the distribution of mass in axillary shoots. At high Pi, axillary leaf area and leaf weight were greater in tomato grown over white mulch than when grown over red mulch. The root-gall index was lower for plants grown over white mulch than similar plants grown over red mulch.

  15. Deep-sequencing transcriptome analysis of field-grown Medicago sativa L. crown buds acclimated to freezing stress.

    PubMed

    Song, Lili; Jiang, Lin; Chen, Yue; Shu, Yongjun; Bai, Yan; Guo, Changhong

    2016-09-01

    Medicago sativa L. (alfalfa) 'Zhaodong' is an important forage legume that can safely survive in northern China where winter temperatures reach as low as -30 °C. Survival of alfalfa following freezing stress depends on the amount and revival ability of crown buds. In order to investigate the molecular mechanisms of frost tolerance in alfalfa, we used transcriptome sequencing technology and bioinformatics strategies to analyze crown buds of field-grown alfalfa during winter. We statistically identified a total of 5605 differentially expressed genes (DEGs) involved in freezing stress including 1900 upregulated and 3705 downregulated DEGs. We validated 36 candidate DEGs using qPCR to confirm the accuracy of the RNA-seq data. Unlike other recent studies, this study employed alfalfa plants grown in the natural environment. Our results indicate that not only the CBF orthologs but also membrane proteins, hormone signal transduction pathways, and ubiquitin-mediated proteolysis pathways indicate the presence of a special freezing adaptation mechanism in alfalfa. The antioxidant defense system may rapidly confer freezing tolerance to alfalfa. Importantly, biosynthesis of secondary metabolites and phenylalanine metabolism, which is of potential importance in coordinating freezing tolerance with growth and development, were downregulated in subzero temperatures. The adaptive mechanism for frost tolerance is a complex multigenic process that is not well understood. This systematic analysis provided an in-depth view of stress tolerance mechanisms in alfalfa.

  16. Degradation by Streptomyces viridosporus T7A of plant material grown under elevated CO2 conditions.

    PubMed

    Ball, A S

    1991-11-15

    The biodegradability of plant material derived from wheat grown under different concentrations of atmospheric CO2 was investigated using the lignocarbohydrate solubilising actinomycete, Streptomyces viridosporus. Growth of S. viridosporus and solubilisation of lignocarbohydrate were highest when wheat grown at ambient CO2 concentrations (350 ppm) was used as C-source. Growth of S. viridosporus and solubilisation were reduced when the plant material was derived from wheat grown at 645 ppm CO2. The results suggest that modifications in plant structure occur when wheat is grown under conditions of elevated atmospheric CO2 which make it more resistant to microbial digestion.

  17. Metal accumulation in poplar plant grown with industrial wastes.

    PubMed

    Giachetti, Giorgio; Sebastiani, Luca

    2006-06-01

    In this study the effects of different levels of industrial wastes on growth traits and metal accumulation in aerial portions were determined for Populusxeuramericana clone I-214. The experiment started in April 2003. Scions of Populusxeuramericana clone I-214, were grown outdoor near Pisa (Italy), in lisimeters filled with soil naturally present in the land around the experimental site, were daily drip irrigated, hand weeded, monthly fertilized, pruned for a unique shoot and cultivated with four increasing treatments: soil non-amended, soil amended with 4.8 kgm(-2), with 9.6 kgm(-2) and with 19.2 kgm(-2) of fresh tannery waste. The climatic parameters were daily recorded throughout the whole experiment. Growth relieves were performed during the growing season. After six months since the plantation of the scions, aerial portions of every plant were harvested for biomass and metal content analyses. Data demonstrated that the waste exerted beneficial effects on poplars mainly through a general increase of growth traits and that the nutrients relocation is the mechanisms involved in modulating growth rate. The concentration and the amount of the mineral elements analysed (N, P, K, Na, Ca, Mg, S, B, Fe, Mn, Cu, Zn, Cr) changed determinately among treatments, organs and position. We concluded that phytoremediation strategies of tannery wastes might be possible and sustainable for polar plantations in soil amended with non-hazardous levels of industrial waste, which maintain total heavy metals concentration close to background values.

  18. The Role of Proanthocyanidins Complex in Structure and Nutrition Interaction in Alfalfa Forage

    PubMed Central

    Jonker, Arjan; Yu, Peiqiang

    2016-01-01

    Alfalfa (Medicago sativa L.) is one of the main forages grown in the world. Alfalfa is a winter hardy, drought tolerant, N-fixing legume with a good longevity, high yield, high nutrient levels, high digestibility, unique structural to non-structural components ratio, high dry matter intake, and high animal productivity per hectare. However, its main limitation is its excessively rapid initial rate of protein degradation in the rumen, which results in pasture bloat and inefficient use of protein with consequent excessive excretions of nitrogen into the environment. Proanthocyanidins are secondary plant metabolites that can bind with protein and thereby reduce the rate and extent of ruminal protein degradation. However, these secondary metabolites do not accumulate in alfalfa. This review aims to firstly describe the events involved in the rapid release of protein from alfalfa and its effect on ruminant nutrition, environmental pollution, and pasture bloat; secondly, to describe occurrence, structure, functions and benefits of moderate amounts of proanthocyanidin; and finally, to describe the development of alfalfa which accumulates moderate amounts of proanthocyanidins. The emphasis of this review focuses on the role of proanthocyanidins compounds in structure and nutrition interaction in ruminant livestock systems. PMID:27223279

  19. The Role of Proanthocyanidins Complex in Structure and Nutrition Interaction in Alfalfa Forage.

    PubMed

    Jonker, Arjan; Yu, Peiqiang

    2016-05-23

    Alfalfa (Medicago sativa L.) is one of the main forages grown in the world. Alfalfa is a winter hardy, drought tolerant, N-fixing legume with a good longevity, high yield, high nutrient levels, high digestibility, unique structural to non-structural components ratio, high dry matter intake, and high animal productivity per hectare. However, its main limitation is its excessively rapid initial rate of protein degradation in the rumen, which results in pasture bloat and inefficient use of protein with consequent excessive excretions of nitrogen into the environment. Proanthocyanidins are secondary plant metabolites that can bind with protein and thereby reduce the rate and extent of ruminal protein degradation. However, these secondary metabolites do not accumulate in alfalfa. This review aims to firstly describe the events involved in the rapid release of protein from alfalfa and its effect on ruminant nutrition, environmental pollution, and pasture bloat; secondly, to describe occurrence, structure, functions and benefits of moderate amounts of proanthocyanidin; and finally, to describe the development of alfalfa which accumulates moderate amounts of proanthocyanidins. The emphasis of this review focuses on the role of proanthocyanidins compounds in structure and nutrition interaction in ruminant livestock systems.

  20. Combined effects of elevated CO2 and herbivore damage on alfalfa and cotton.

    PubMed

    Agrell, Jep; Anderson, Peter; Oleszek, Wieslaw; Stochmal, Anna; Agrell, Cecilia

    2004-11-01

    We examined herbivore-induced responses of alfalfa (Medicago sativa) and cotton (Gossypium hirsutum) under different CO2 conditions. Plants were grown under ambient (350 ppm) or elevated (700 ppm) CO2 levels, and were either damaged or undamaged by Spodoptera littoralis larvae. At harvest, growth of undamaged (control) plants was determined, and foliar chemical composition of both undamaged and damaged plants was analyzed. Cotton grew faster overall and showed a greater increase in growth in response to CO2 enrichment than did alfalfa. Elevated CO2 levels increased starch and decreased nitrogen levels in damaged alfalfa and undamaged cotton plants. Alfalfa saponin levels were significantly increased by elevated CO2 and damage. Regarding specific saponins, medicagenic acid bidesmoside (3GlcA,28AraRhaXyl medicagenate) concentrations were reduced by high CO2, whereas zanhic acid tridesmoside (3GlcGlcGlc,23Ara,28AraRhaXylApi Za) levels were unaffected by the treatments. Soyasaponin I (3GlcAGalRha soyasapogenol B) was only detected in minute amounts. Alfalfa flavonoid analyses showed that total flavonoid levels were similar between treatments, although free apigenin increased and apigenin glucoside (7-O-[2-O-feruloyl-beta-D-glucuronopyranozyl (1-->2)-O-8-D-glucuronopyranozyl]-4'-O-beta-D-glucuronopyranozide apigenin) decreased in CO2-enriched plants. In cotton, herbivore damage increased levels of total terpenoid aldehydes, gossypol, hemigossypolone, the heliocides H1 and H4, but not H2 and H3, whereas CO2 enrichment had no effect. These results demonstrate that combined effects of CO2 and herbivore damage vary between plant species, which has implications for the competitive balance within plant communities.

  1. [Soil dryness characteristics of alfalfa cropland and optimal growth years of alfalfa on the Loess Plateau of central Gansu, China].

    PubMed

    Luo, Zhu-zhu; Li, Ling-ling; Niu, Yi-ning; Cai, Li-qun; Zhang, Ren-zhi; Xie, Jun-hong

    2015-10-01

    This paper investigated soil moisture in alfalfa (Medicago sativa) cropland with different growth years (1, 3, 8, 12 and 14 years) and discussed the optimum growth years of alfalfa on the Loess Plateau of central Gansu. The results showed that the soil moisture along 0-300 cm soil profile of alfalfa croplands with different growth years was obviously lower than that of the local soil stable moisture. The soil water contents in croplands with alfalfa that had grown for 12 and 14 years were only 9.2% and 7.1% of local soil stable moisture, respectively, which were even lower than the lower limit of alfalfa growth. The average soil dryness indexes along 0-300 cm soil profile in 1, 3, 8, 12 and 14 years alfalfa croplands were 125.4%, 30.5%, 18.4%, -34.2% and -83.3% respectively. The results indicated that soil dryness occurred to varying degrees with different growth years except croplands with alfalfa grown for 1 year. With the increase of growth years of alfalfa, the soil dryness intensity increased and the soil dryness rate decreased. According to the soil moisture and alfalfa productivity results in this study, it could be concluded that the optimum growth years of alfalfa are 8-10 years in semiarid areas of the Loess Plateau.

  2. Alfalfa production with subsurface drip irrigation in the Central Great Plains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Irrigated alfalfa production is gaining interest because of the growing number of dairies in the semi-arid U.S. Central Great Plains and its longstanding superior profitability compared to other alternative crops grown in the region. Irrigation requirements for alfalfa are great because of alfalfa's...

  3. Increased photosynthetic acclimation in alfalfa associated with arbuscular mycorrhizal fungi (AMF) and cultivated in greenhouse under elevated CO2.

    PubMed

    Goicoechea, Nieves; Baslam, Marouane; Erice, Gorka; Irigoyen, Juan José

    2014-11-15

    Medicago sativa L. (alfalfa) can exhibit photosynthetic down-regulation when grown in greenhouse conditions under elevated atmospheric CO2. This forage legume can establish a double symbiosis with nitrogen fixing bacteria and arbuscular mycorrhizal fungi (AMF), which may increase the carbon sink effect of roots. Our aim was to assess whether the association of alfalfa with AMF can avoid, diminish or delay the photosynthetic acclimation observed in previous studies performed with nodulated plants. The results, however, showed that mycorrhizal (M) alfalfa at the end of their vegetative period had lower carbon (C) discrimination than non-mycorrhizal (NM) controls, indicating photosynthetic acclimation under ECO2 in plants associated with AMF. Decreased C discrimination was due to the acclimation of conductance, since the amount of Rubisco and the expression of genes codifying both large and small subunits of Rubisco were similar or slightly higher in M than in NM plants. Moreover, M alfalfa accumulated a greater amount of soluble sugars in leaves than NM plants, thus favoring a down-regulation effect on photosynthetic rates. The enhanced contents of sugars in leaves coincided with a reduced percentage of arbuscules in roots, suggesting decreased sink of carbohydrates from shoots to roots in M plants. The shorter life cycle of alfalfa associated with AMF in comparison with the NM controls may also be related to the accelerated photosynthetic acclimation in M plants. Further research is needed to clarify to what extent this behavior could be extrapolated to alfalfa cultivated in the field and subjected to periodic cutting of shoots under climatic change scenarios.

  4. Planting date effects on the nutritive value of fall-grown oat cultivars

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fall-grown oat (Avena sativa L.) shows potential to fill an important niche as emergency fall forage throughout central Wisconsin. Our objectives were to assess the effects of planting date on the nutritive value of fall-grown oat from four cultivars exhibiting diverse maturation characteristics. Du...

  5. Effect of Plant Spacing on Microclimate and Rhizoctonia Web Blight Development in Container Grown Azalea

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia web blight is a reoccurring problem in compact varieties of container-grown azalea (Rhododendron sp.) in the Gulf Coast States. During the summers of 2002 and 2003, disease severity was measured weekly in the inoculated center plant of plots consisting of 49 ‘Gumpo’ azalea plants. Plant ...

  6. Physiological response of glandular-haired alfalfa to potato leafhopper (Hemiptera: Cicadellidae) injury.

    PubMed

    Lamp, W O; Alexander, L C; Nguyen, M

    2007-02-01

    Plant tolerance to herbivory is a key approach for managing pests. In alfalfa, Medicago sativa, the potato leafhopper, Empoasca fabae, is a major pest as a result of the cascade of plant responses to piercing-sucking injury. To identify tolerance to its injury based on alfalfa physiology, experiments were conducted in the field and greenhouse. In our comparison of the response of field-grown alfalfa cultivars to standardized leafhopper densities, net photosynthesis and transpiration rates of 'Geneva' leaves were reduced by 18 and 21%, respectively, by leafhopper presence compared with a rate change of <1% of resistant 'EverGreen' leaves. Under greenhouse conditions, alfalfa clones varied in their level of gas exchange (net photosynthesis and transpiration) and stem elongation responses to leafhopper injury. For example, in the comparison of seven clones, net photosynthesis declined an average of 40.7% with leafhopper injury, although individual clones varied from 26.6 to 74.3% reduction. Internode elongation after 2 d was 60.3% less on injured stems compared with healthy stems, but again, the individual clones varied from 17.3 to 91.9%. In a time-course study of selected clones, clones varied in their level of injury just after and 3 d after insect removal. Gas exchange responses of all clones recovered by 7 d after cessation of injury. In a choice test, leafhoppers spent similar amounts of time on the susceptible clone and the most tolerant clone; however, their precise feeding behaviors were not measured. Thus, the variable response of clones to injury may be either true physiological tolerance or antixenosis from a change in feeding behavior. This study showed putative tolerance to leafhopper injury among alfalfa genotypes, suggesting that tolerance could be the basis for crop protection in alfalfa from potato leafhopper injury.

  7. Evidence of Association of Salmonellae with Tomato Plants Grown Hydroponically in Inoculated Nutrient Solution

    PubMed Central

    Guo, Xuan; van Iersel, Marc W.; Chen, Jinru; Brackett, Robert E.; Beuchat, Larry R.

    2002-01-01

    The possibility of uptake of salmonellae by roots of hydroponically grown tomato plants was investigated. Within 1 day of exposure of plant roots to Hoagland nutrient solution containing 4.46 to 4.65 log10 CFU of salmonellae/ml, the sizes of the pathogen populations were 3.01 CFU/g of hypocotyls and cotyledons and 3.40 log10 CFU/g of stems for plants with intact root systems (control) and 2.55 log10 CFU/g of hypocotyls and cotyledons for plants from which portions of the roots had been removed. A population of ≥3.38 log10 CFU/g of hypocotyls-cotyledons, stems, and leaves of plants grown for 9 days was detected regardless of the root condition. Additional studies need to be done to unequivocally demonstrate that salmonellae can exist as endophytes in tomato plants grown under conditions that simulate commonly used agronomic practices. PMID:12089054

  8. Yield performance of cowpea plant introductions grown in calcareous soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cowpea or Southernpea [Vigna unguiculata (L.) Walp.] is an important legume crop used as a feed for livestock, as a green vegetable and for consumption of its dry beans which provide 22-25% protein. The crop is very sensitive to alkaline soil conditions. When grown at a soil pH of 7.5 or higher, co...

  9. Soybean micronutrient content in irrigated plants grown in the Midsouth

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Micronutrients are essential to soybean (Glycine max L. Merr.) but required in minute quantities. Concentrations and tissue contents of Fe, B, Zn, Mn and Cu were determined for two MG IV and one MG V irrigated cultivars grown in twin-rows in the Mississippi Delta on clay and sandy loam soil sites i...

  10. Alfalfa: bioenergy and more

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alfalfa (Medicago sativa) has the potential to be a significant contributor to America's renewable energy future. In an alfalfa biomass energy production system, alfalfa forage would be separated into stem and leave fractions. The stems would be processed to produce energy, and the leaves would be s...

  11. Broadening the U.S. alfalfa germplasm base

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Over 4000 alfalfa (Medicago sativa L.) plant introductions (PIs) exist in the USDA-ARS National Plant Germplasm System (NPGS). NAAIC has discussed/proposed pre-breeding efforts to utilize this germplasm for creating pre-commercial alfalfa germplasm. Funding constraints have been one impediment to th...

  12. The response of carbon metabolism and antioxidant defenses of alfalfa nodules to drought stress and to the subsequent recovery of plants.

    PubMed

    Naya, Loreto; Ladrera, Ruben; Ramos, Javier; González, Esther M; Arrese-Igor, Cesar; Minchin, Frank R; Becana, Manuel

    2007-06-01

    Alfalfa (Medicago sativa) plants were exposed to drought to examine the involvement of carbon metabolism and oxidative stress in the decline of nitrogenase (N(2)ase) activity. Exposure of plants to a moderate drought (leaf water potential of -1.3 MPa) had no effect on sucrose (Suc) synthase (SS) activity, but caused inhibition of N(2)ase activity (-43%), accumulation of succinate (+36%) and Suc (+58%), and up-regulation of genes encoding cytosolic CuZn-superoxide dismutase (SOD), plastid FeSOD, cytosolic glutathione reductase, and bacterial MnSOD and catalases B and C. Intensification of stress (-2.1 MPa) decreased N(2)ase (-82%) and SS (-30%) activities and increased malate (+40%), succinate (+68%), and Suc (+435%). There was also up-regulation (mRNA) of cytosolic ascorbate peroxidase and down-regulation (mRNA) of SS, homoglutathione synthetase, and bacterial catalase A. Drought stress did not affect nifH mRNA level or leghemoglobin expression, but decreased MoFe- and Fe-proteins. Rewatering of plants led to a partial recovery of the activity (75%) and proteins (>64%) of N(2)ase, a complete recovery of Suc, and a decrease of malate (-48%) relative to control. The increase in O(2) diffusion resistance, the decrease in N(2)ase-linked respiration and N(2)ase proteins, the accumulation of respiratory substrates and oxidized lipids and proteins, and the up-regulation of antioxidant genes reveal that bacteroids have their respiratory activity impaired and that oxidative stress occurs in nodules under drought conditions prior to any detectable effect on SS or leghemoglobin. We conclude that a limitation in metabolic capacity of bacteroids and oxidative damage of cellular components are contributing factors to the inhibition of N(2)ase activity in alfalfa nodules.

  13. Root Zone Respiration on Hydroponically Grown Wheat Plant Systems

    NASA Technical Reports Server (NTRS)

    Soler-Crespo, R. A.; Monje, O. A.

    2010-01-01

    Root respiration is a biological phenomenon that controls plant growth and physiological development during a plant's lifespan. This process is dependent on the availability of oxygen in the system where the plant is located. In hydroponic systems, where plants are submerged in a solution containing vital nutrients but no type of soil, the availability of oxygen arises from the dissolved oxygen concentration in the solution. This oxygen concentration is dependent on the , gas-liquid interface formed on the upper surface of the liquid, as given by Henry's Law, depending on pressure and temperature conditions. Respiration rates of the plants rise as biomass and root zone increase with age. The respiration rate of Apogee wheat plants (Triticum aestivum) was measured as a function of light intensity (catalytic for photosynthesis) and CO2 concentration to determine their effect on respiration rates. To determine their effects on respiration rate and plant growth microbial communities were introduced into the system, by Innoculum. Surfactants were introduced, simulating gray-water usage in space, as another factor to determine their effect on chemical oxygen demand of microbials and on respiration rates of the plants. It is expected to see small effects from changes in CO2 concentration or light levels, and to see root respiration decrease in an exponential manner with plant age and microbial activity.

  14. Abscisic acid substantially inhibits senescence of cucumber plants (Cucumis sativus) grown under low nitrogen conditions.

    PubMed

    Oka, Mariko; Shimoda, Yousuke; Sato, Naoko; Inoue, Junya; Yamazaki, Teru; Shimomura, Norihiro; Fujiyama, Hideyasu

    2012-05-15

    Low nitrogen (N) availability such as that found in both dry land and tropical regions limits plant growth and development. The relationship between the level of abscisic acid (ABA) in a plant and its growth under low-N conditions was investigated. The level of ABA in cucumber (Cucumis sativus) plants under low-N conditions was significantly higher at 10 and 20 d after transplantation compared with that under sufficient-N conditions. Chlorophyll was preserved in the aerial parts of cucumber plants grown under low-N conditions in the presence of ABA, while there was no significant difference between control plants and ABA-applied plants under sufficient-N conditions. ABA suppressed the reduction of chlorophyll biosynthesis under low-N conditions but not under sufficient-N conditions. On the other hand, ABA decreased the expression of the chlorophyll degradation gene in older cucumber plants grown under both conditions. In addition, transcript and protein levels of a gene encoding a chlorophyll a/b binding protein were positively correlated with ABA concentration under low-N conditions. The chloroplasts in control plants were round, and the stack of thylakoid membranes was reduced compared with that of plants treated with ABA 10(-5) M. These results strongly suggest that ABA is accumulated in cucumber plants grown under low-N conditions and that accumulated ABA promotes chlorophyll biosynthesis and inhibits its degradation in those plants.

  15. Effects of zinc toxicity on sugar beet (Beta vulgaris L.) plants grown in hydroponics.

    PubMed

    Sagardoy, R; Morales, F; López-Millán, A-F; Abadía, A; Abadía, J

    2009-05-01

    The effects of high Zn concentration were investigated in sugar beet (Beta vulgaris L.) plants grown in a controlled environment in hydroponics. High concentrations of Zn sulphate in the nutrient solution (50, 100 and 300 microm) decreased root and shoot fresh and dry mass, and increased root/shoot ratios, when compared to control conditions (1.2 microm Zn). Plants grown with excess Zn had inward-rolled leaf edges and a damaged and brownish root system, with short lateral roots. High Zn decreased N, Mg, K and Mn concentrations in all plant parts, whereas P and Ca concentrations increased, but only in shoots. Leaves of plants treated with 50 and 100 microm Zn developed symptoms of Fe deficiency, including decreases in Fe, chlorophyll and carotenoid concentrations, increases in carotenoid/chlorophyll and chlorophyll a/b ratios and de-epoxidation of violaxanthin cycle pigments. Plants grown with 300 microm Zn had decreased photosystem II efficiency and further growth decreases but did not have leaf Fe deficiency symptoms. Leaf Zn concentrations of plants grown with excess Zn were high but fairly constant (230-260 microg.g(-1) dry weight), whereas total Zn uptake per plant decreased markedly with high Zn supply. These data indicate that sugar beet could be a good model to investigate Zn homeostasis mechanisms in plants, but is not an efficient species for Zn phytoremediation.

  16. Mortality of container-grown blueberry plants inoculated with Phytophthora cinnamomi Rands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We conducted four studies to evaluate the effect of Phytophthora cinnamomi isolates and inoculum delivery methods on root rot development and mortality of container-grown blueberry plants. Phytophthora cinnamomi isolates were obtained from the root zone of symptomatic blueberry plants and identifie...

  17. Glyphosate-tolerant alfalfa is compositionally equivalent to conventional alfalfa (Medicago sativa L.).

    PubMed

    McCann, Melinda C; Rogan, Glennon J; Fitzpatrick, Sharie; Trujillo, William A; Sorbet, Roy; Hartnell, Gary F; Riodan, Susan G; Nemeth, Margaret A

    2006-09-20

    Glyphosate-tolerant alfalfa (GTA) was developed to withstand over-the-top applications of glyphosate, the active ingredient in Roundup agricultural herbicides. As a part of the safety assessment, GTA (designated J101 x J163) was grown under controlled field conditions at geographically diverse locations within the United States during the 2001 and 2003 field seasons along with control and other conventional alfalfa varieties for compositional assessment. Field trials were conducted using a randomized complete block design with four replication blocks at each site. Alfalfa forage was harvested at the late bud to early bloom stage from each plot at five field sites in 2001 (establishment year) and from four field sites in 2003 (third year of stand). The concentration of proximate constituents, fibers, amino acids, coumestrol, and minerals in the forage was measured. The results showed that the forage from GTA J101 x J163 is compositionally equivalent to forage from the control and conventional alfalfa varieties.

  18. Phyllosphere Microbiota Composition and Microbial Community Transplantation on Lettuce Plants Grown Indoors

    PubMed Central

    Williams, Thomas R.

    2014-01-01

    ABSTRACT The aerial surfaces of plants, or phyllosphere, are microbial habitats important to plant and human health. In order to accurately investigate microbial interactions in the phyllosphere under laboratory conditions, the composition of the phyllosphere microbiota should be representative of the diversity of microorganisms residing on plants in nature. We found that Romaine lettuce grown in the laboratory contained 10- to 100-fold lower numbers of bacteria than age-matched, field-grown lettuce. The bacterial diversity on laboratory-grown plants was also significantly lower and contained relatively higher proportions of Betaproteobacteria as opposed to the Gammaproteobacteria-enriched communities on field lettuce. Incubation of field-grown Romaine lettuce plants in environmental growth chambers for 2 weeks resulted in bacterial cell densities and taxa similar to those on plants in the field but with less diverse bacterial populations overall. In comparison, the inoculation of laboratory-grown Romaine lettuce plants with either freshly collected or cryopreserved microorganisms recovered from field lettuce resulted in the development of a field-like microbiota on the lettuce within 2 days of application. The survival of an inoculated strain of Escherichia coli O157:H7 was unchanged by microbial community transfer; however, the inoculation of E. coli O157:H7 onto those plants resulted in significant shifts in the abundance of certain taxa. This finding was strictly dependent on the presence of a field-associated as opposed to a laboratory-associated microbiota on the plants. Phyllosphere microbiota transplantation in the laboratory will be useful for elucidating microbial interactions on plants that are important to agriculture and microbial food safety. PMID:25118240

  19. Spectral quality affects disease development of three pathogens on hydroponically grown plants

    NASA Technical Reports Server (NTRS)

    Schuerger, A. C.; Brown, C. S.; Sager, J. C. (Principal Investigator)

    1997-01-01

    Plants were grown under light-emitting diode (LED) arrays with various spectra to determine the effects of light quality on the development of diseases caused by tomato mosaic virus (ToMV) on pepper (Capsicum annuum L.), powdery mildew [Sphaerotheca fuliginea (Schlectend:Fr.) Pollaci] on cucumber (Cucumis sativus L.), and bacterial wilt (Pseudomonas solanacearum Smith) on tomato (Lycopersicon esculentum Mill.). One LED (660) array supplied 99% red light at 660 nm (25 nm bandwidth at half-peak height) and 1% far-red light between 700 to 800 nm. A second LED (660/735) array supplied 83% red light at 660 nm and 17% far-red light at 735 nm (25 nm bandwidth at half-peak height). A third LED (660/BF) array supplied 98% red light at 660 nm, 1% blue light (BF) between 350 to 550 nm, and 1% far-red light between 700 to 800 nm. Control plants were grown under broad-spectrum metal halide (MH) lamps. Plants were grown at a mean photon flux (300 to 800 nm) of 330 micromoles m-2 s-1 under a 12-h day/night photoperiod. Spectral quality affected each pathosystem differently. In the ToMV/pepper pathosystem, disease symptoms developed slower and were less severe in plants grown under light sources that contained blue and UV-A wavelengths (MH and 660/BF treatments) compared to plants grown under light sources that lacked blue and UV-A wavelengths (660 and 660/735 LED arrays). In contrast, the number of colonies per leaf was highest and the mean colony diameters of S. fuliginea on cucumber plants were largest on leaves grown under the MH lamp (highest amount of blue and UV-A light) and least on leaves grown under the 660 LED array (no blue or UV-A light). The addition of far-red irradiation to the primary light source in the 660/735 LED array increased the colony counts per leaf in the S. fuliginea/cucumber pathosystem compared to the red-only (660) LED array. In the P. solanacearum/tomato pathosystem, disease symptoms were less severe in plants grown under the 660 LED array, but the

  20. Spectral quality affects disease development of three pathogens on hydroponically grown plants.

    PubMed

    Schuerger, A C; Brown, C S

    1997-02-01

    Plants were grown under light-emitting diode (LED) arrays with various spectra to determine the effects of light quality on the development of diseases caused by tomato mosaic virus (ToMV) on pepper (Capsicum annuum L.), powdery mildew [Sphaerotheca fuliginea (Schlectend:Fr.) Pollaci] on cucumber (Cucumis sativus L.), and bacterial wilt (Pseudomonas solanacearum Smith) on tomato (Lycopersicon esculentum Mill.). One LED (660) array supplied 99% red light at 660 nm (25 nm bandwidth at half-peak height) and 1% far-red light between 700 to 800 nm. A second LED (660/735) array supplied 83% red light at 660 nm and 17% far-red light at 735 nm (25 nm bandwidth at half-peak height). A third LED (660/BF) array supplied 98% red light at 660 nm, 1% blue light (BF) between 350 to 550 nm, and 1% far-red light between 700 to 800 nm. Control plants were grown under broad-spectrum metal halide (MH) lamps. Plants were grown at a mean photon flux (300 to 800 nm) of 330 micromoles m-2 s-1 under a 12-h day/night photoperiod. Spectral quality affected each pathosystem differently. In the ToMV/pepper pathosystem, disease symptoms developed slower and were less severe in plants grown under light sources that contained blue and UV-A wavelengths (MH and 660/BF treatments) compared to plants grown under light sources that lacked blue and UV-A wavelengths (660 and 660/735 LED arrays). In contrast, the number of colonies per leaf was highest and the mean colony diameters of S. fuliginea on cucumber plants were largest on leaves grown under the MH lamp (highest amount of blue and UV-A light) and least on leaves grown under the 660 LED array (no blue or UV-A light). The addition of far-red irradiation to the primary light source in the 660/735 LED array increased the colony counts per leaf in the S. fuliginea/cucumber pathosystem compared to the red-only (660) LED array. In the P. solanacearum/tomato pathosystem, disease symptoms were less severe in plants grown under the 660 LED array, but the

  1. Nutrient Considerations for Plants Grown Under Space Flight Conditions

    NASA Technical Reports Server (NTRS)

    Levine, Howard G.; Krikorian, Abraham D.

    2006-01-01

    We present here results on the analysis of 100 mL medium samples extracted from sterilized foam (Smithers-Oasis, Kent OH) used to support the growth of both dicotyledonous (Haplopappus gracilis, n=75) and monocotyledonous (Hemerocallis cv Autumn Blaze, n=25) aseptic plants in NASA's Plant Growth Unit (PGU) during the 5-day CHROMEX-01 Space Shuttle flight (March 1989, STS-29). At recovery, the medium remaining within each of the five floral foam blocks (for both the space flight and ground control experiments) was extracted under vacuum, filtered and subjected to elemental analyses. Concentration levels of some elements remained the same, while some decreased and others increased. A unique aspect of this experiment was that all plants were either aseptic tissue culture generated plantlets or sterile seedling clones, and the design of the PGU facilitated the maintenance of asepsis throughout the mission (confirmed by postflight microbial sampling). This permitted the elimination of microbial considerations in the interpretation of the data. The significance of these findings for growing plants in altered gravity environments are discussed.

  2. Nutrient considerations for Plants grown under Spaceflight conditions.

    NASA Astrophysics Data System (ADS)

    Levine, H. G.; Krikorian, A. D.

    We present here results on the analysis of 100 mL medium samples extracted from sterilized floral foam Smithers-Oasis Kent OH used to support the growth of both dicotyledonous Haplopappus gracilis n 75 and monocotyledonous Hemerocallis cv Autumn Blaze n 25 aseptic plants in NASA s Plant Growth Unit PGU during the 5-day CHROMEX-01 Space Shuttle flight March 1989 STS-29 At recovery the medium remaining within each of the five foam blocks for both the space flight and ground control experiments was extracted under vacuum filtered and subjected to elemental analyses Concentration levels of some elements remained the same while some decreased and others increased A unique aspect of this experiment was that all plants were either aseptic tissue culture generated plantlets or sterile seedling clones and the design of the PGU facilitated the maintenance of asepsis throughout the mission confirmed by post-flight microbial sampling This permitted the elimination of microbial considerations in the interpretation of the data The significance of these findings for growing plants in altered gravity environments is discussed

  3. Synthetic mimicking of plant oils and comparison with naturally grown products in polyurethane synthesis.

    PubMed

    Coles, Stuart R; Barker, Guy; Clark, Andrew J; Kirwan, Kerry; Jacobs, Daniel; Makenji, Kylash; Pink, David

    2008-06-11

    The use of plant oils as industrial feedstocks can often be hampered by their lack of optimization towards a particular process, as well as their development being risky; growing suitable volumes of crops to test can take up to five years. To circumvent this, we aimed to discover a method that would mimic plant oil profiles in the laboratory, and show that they exhibited similar properties to the naturally grown plant oils in a given process. Using the synthesis of polyurethanes as an example, we have synthesized six different polymers and demonstrated that plant oils will produce polymers with similar physical properties to those oils mimicked in the laboratory. The use of this mimicking process can be extended to other types of polymers to obtain a method for predicting the properties of a given material based on the plant oil composition of a crop before it is grown in bulk.

  4. Risks and benefits of compost-like materials prepared by the thermal treatment of raw scallop hepatopancreas for supplying cadmium and the growth of alfalfa (Medicago sativa L.).

    PubMed

    Ushijima, Kensuke; Fukushima, Masami; Kanno, Shinya; Kanno, Itoko; Ohnishi, Mitsuhiro

    2016-01-01

    Scallop hepatopancreas, fishery waste, contains relatively high levels of Cd and organic nitrogen compounds, the latter of which represent a fertilizer. In this study, raw scallop hepatopancreas tissue was thermally treated with sawdust and red loam in the presence of an iron catalyst to produce compost-like materials (CLMs). Two CLM samples were prepared by varying the content of raw scallop hepatopancreas tissue: 46 wt.% for CLM-1 and 18 wt.% for CLM-2. Mixtures of control soil (CTL) and CLMs (CLM content: 10 and 25 wt.%) were examined for the growth of alfalfa (Medicago sativa L.) to evaluate the risks and benefits of using this material for fertilization. The Cd content in shoots and roots of alfalfa, that were grown in the presence of CLMs, was significantly higher than those for the plants grown in the CTL, indicating that Cd had accumulated in the plants from CLMs. The accumulation of Cd in the alfalfa roots was quite high in the case of the 25% CLM-1 sample. However, alfalfa growth was significantly promoted in the presence of 10% CLM-1. This can be attributed to the higher levels of nitrogen and humic substances, which serve as fertilizer components. Although the fertilization effect in case of CLM-1showed a potential benefit, the accumulation of Cd in alfalfa was clearly increased in the presence of both CLMs. In conclusion, the use of CLMs produced from raw scallop hepatopancreas tissue can be considered to have a desirable benefit from standpoint of its use as fertilizer, but is accompanied by a risk of the accumulation of Cd in alfalfa plants.

  5. Secretomic survey of Trichoderma harzianum grown on plant biomass substrates.

    PubMed

    Gómez-Mendoza, Diana Paola; Junqueira, Magno; do Vale, Luis Henrique Ferreira; Domont, Gilberto Barbosa; Ferreira Filho, Edivaldo Ximenes; Sousa, Marcelo Valle de; Ricart, Carlos André Ornelas

    2014-04-04

    The present work aims at characterizing T. harzianum secretome when the fungus is grown in synthetic medium supplemented with one of the four substrates: glucose, cellulose, xylan, and sugarcane bagasse (SB). The characterization was done by enzymatic assays and proteomic analysis using 2-DE/MALDI-TOF and gel-free shotgun LC-MS/MS. The results showed that SB induced the highest cellulolytic and xylanolytic activities when compared with the other substrates, while remarkable differences in terms of number and distribution of protein spots in 2-DE gels were also observed among the samples. Additionally, treatment of the secretomes with PNGase F revealed that most spot trails in 2-DE gels corresponded to N-glycosylated proteoforms. The LC-MS/MS analysis of the samples identified 626 different protein groups, including carbohydrate-active enzymes and accessory, noncatalytic, and cell-wall-associated proteins. Although the SB-induced secretome displayed the highest cellulolytic and xylanolytic activities, it did not correspond to a higher proteome complexity because CM-cellulose-induced secretome was significantly more diverse. Among the identified proteins, 73% were exclusive to one condition, while only 5% were present in all samples. Therefore, this study disclosed the variation of T. harzianum secretome in response to different substrates and revealed the diversity of the fungus enzymatic toolbox.

  6. Physiological Response of Plants Grown on Porous Ceramic Tubes

    NASA Technical Reports Server (NTRS)

    Tsao, David; Okos, Martin

    1997-01-01

    This research involves the manipulation of the root-zone water potential for the purposes of discriminating the rate limiting step in the inorganic nutrient uptake mechanism utilized by higher plants. This reaction sequence includes the pathways controlled by the root-zone conditions such as water tension and gradient concentrations. Furthermore, plant based control mechanisms dictated by various protein productions are differentiated as well. For the nutrients limited by the environmental availability, the kinetics were modeled using convection and diffusion equations. Alternatively, for the nutrients dependent upon enzyme manipulations, the uptakes are modeled using Michaelis-Menten kinetics. In order to differentiate between these various mechanistic steps, an experimental apparatus known as the Porous Ceramic Tube - Nutrient Delivery System (PCT-NDS) was used. Manipulation of the applied suction pressure circulating a nutrient solution through this system imposes a change in the matric component of the water potential. This compensates for the different osmotic components of water potential dictated by nutrient concentration. By maintaining this control over the root-zone conditions, the rate limiting steps in the uptake of the essential nutrients into tomato plants (Lycopersicon esculentum cv. Cherry Elite) were differentiated. Results showed that the uptake of some nutrients were mass transfer limited while others were limited by the enzyme kinetics. Each of these were adequately modeled with calculations and discussions of the parameter estimations provided.

  7. Alfalfa nitrogen credit to first-year corn: potassium, regrowth, and tillage timing effects

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Compared to corn (Zea mays L.) following corn, N guidelines for corn following alfalfa (Medicago sativa L.) in the U.S. Corn Belt suggest that N rates for first-year corn after alfalfa be reduced by about 168 kg N/ha when 43 to 53 alfalfa plants per square meter are present at termination; however, ...

  8. Soil N to corn after alfalfa through tillage and regrowth management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Planting corn after alfalfa can eliminate or greatly reduce the nitrogen (N) fertilizer requirement for first-year corn while increasing corn yield potential due to the rotation effect. Current University of Minnesota guidelines regarding alfalfa N credits to corn are based on alfalfa stand density ...

  9. Modeling feral alfalfa (Medicago sativa subsp. sativa L.) occurrence using topographical and environmental variables

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Because alfalfa is a perennial species cross pollinated by bees and can establish along roadsides and ruderal areas, there is concern that feral plants can serve as reservoirs and conduits for transgenic genes. The objective of this study was to survey feral alfalfa in alfalfa seed production areas ...

  10. Characterization of culturable bacterial endophytes and their capacity to promote plant growth from plants grown using organic or conventional practices

    PubMed Central

    Xia, Ye; DeBolt, Seth; Dreyer, Jamin; Scott, Delia; Williams, Mark A.

    2015-01-01

    Plants have a diverse internal microbial biota that has been shown to have an important influence on a range of plant health attributes. Although these endophytes have been found to be widely occurring, few studies have correlated agricultural production practices with endophyte community structure and function. One agricultural system that focuses on preserving and enhancing soil microbial abundance and biodiversity is organic farming, and numerous studies have shown that organically managed system have increased microbial community characteristics. Herein, the diversity and specificity of culturable bacterial endophytes were evaluated in four vegetable crops: corn, tomato, melon, and pepper grown under organic or conventional practices. Endophytic bacteria were isolated from surface-sterilized shoot, root, and seed tissues and sequence identified. A total of 336 bacterial isolates were identified, and grouped into 32 species and five phyla. Among these, 239 isolates were from organically grown plants and 97 from those grown conventionally. Although a diverse range of bacteria were documented, 186 were from the Phylum Firmicutes, representing 55% of all isolates. Using the Shannon diversity index, we observed a gradation of diversity in tissues, with shoots and roots having a similar value, and seeds having the least diversity. Importantly, endophytic microbial species abundance and diversity was significantly higher in the organically grown plants compared to those grown using conventional practices, potentially indicating that organic management practices may increase endophyte presence and diversity. The impact that these endophytes could have on plant growth and yield was evaluated by reintroducing them into tomato plants in a greenhouse environment. Of the bacterial isolates tested, 61% were found to promote tomato plant growth and 50–64% were shown to enhance biomass accumulation, illustrating their potential agroecosystem application. PMID:26217348

  11. Intended release and actual retention of alfalfa leafcutting bees (hymenoptera: megachilidae) for pollination in commercial alfalfa seed fields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Low, medium, and high stocking densities of Megachile rotundata, the alfalfa leafcutting bee, were released over four years in three research plots of Utah alfalfa planted at seed-production rates. A low number of bees (46-79% of released) survived the incubation and field emergence processes, and ...

  12. Opportunities exist to improve alfalfa and manure nitrogen crediting in corn following alfalfa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A survey was conducted in 2012 to evaluate the acceptance of fertilizer and manure N extension N rate guidelines for corn (Zea mays L.) grown as the first (AC) and second (ACC) crop following alfalfa (Medicago sativa L.) during 2009 to 2011 in Minnesota. There were 421 valid responses for AC and 273...

  13. Rhizoctonia Species Associated With Bark Media and Plant Strata of Container-Grown Azalea

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Symptoms of Rhizoctonia web blight, caused predominantly by binucleate Rhizoctonia (BNR) anastomosis group U, develops annually from late-June to mid-September on container-grown azaleas (Rhododendron spp.) in the southern United States. In 2005 and 2006, ‘Gumpo White’ azalea plants with a disease ...

  14. Nutrient uptake and loss by container-grown deciduous and evergreen Rhododendron nursery plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The influence of N fertilizer application on plant uptake and demand for other nutrients was evaluated from May 2005 to February 2006 in container-grown evergreen Rhododendron ‘P.J.M. Compact’ (PJM) and ‘English Roseum’ (ER) and deciduous Rhododendron ‘Gibraltar’ (AZ). Increased N-availability incre...

  15. Planting date effects on the yield and nutritive value of fall-grown oat cultivars

    Technology Transfer Automated Retrieval System (TEKTRAN)

    For the dairy industry within the north-central U.S., options for producing emergency forage are limited when late-summer or fall inventories are inadequate, primarily because of the relatively short growing season. Fall-grown cereal crops can fill this niche, but knowing what to plant and when to p...

  16. Ractopamine up take by alfalfa (Medicago sativa) and wheat (Triticum aestivum) from soil.

    PubMed

    Shelver, Weilin L; DeSutter, Thomas M

    2015-08-01

    Ractopamine is a beta adrenergic agonist used as a growth promoter in swine, cattle and turkeys. To test whether ractopamine has the potential to accumulate in plants grown in contaminated soil, a greenhouse study was conducted with alfalfa (Medicago sativa) and wheat (Triticum aestivum) grown in two soils having different concentrations of organic matter (1.3% and 2.1%), amended with 0, 0.5, and 10 μg/g of ractopamine. Plant growth ranged from 2.7 to 8.8 g dry weight (dw) for alfalfa, and 8.7 to 40 g dw for wheat and was generally greater in the higher organic matter content soil. The uptake of ractopamine in plant tissues ranged from non-detectable to 897 ng/g and was strongly dependent on soil ractopamine concentration across soil and plant tissue. When adjusted to the total fortified quantities, the amount of ractopamine taken up by the plant tissue was low, <0.01% for either soil.

  17. Allelopathic effect of alfalfa (Medicago sativa) on bladygrass (Imperata cylindrica).

    PubMed

    Abdul-Rahman, A A; Habib, S A

    1989-09-01

    Greenhouse and laboratory experiments were conducted at the Agricultural and Water Resources Research Center Station, Baghdad, in 1985 and 1986 to investigate the possible allelopathic potential of alfalfa (Medicago saliva L.) and its decomposed residues on bladygrass (Imperata cylin-drica L. Beauv.), a noxious weed in Iraq, and to isolate, characterize, and quantify possible allelopathic agents in alfalfa residues and root exudates. Results indicated that decomposed alfalfa roots and their associated soil produced a 51-56% reduction in bladygrass seed germination. Root and shoot length of bladygrass seedlings were reduced by an average of 88%. Decayed and undecayed mixtures of alfalfa roots and soil at 0.015∶1 (w/w) inhibited bladygrass seedlings reproduced from rhizomes by 30 and 42%. It was found that root exudates of alfalfa seedlings caused significant reduction in shoot and root dry weights of bladygrass seedlings when alfalfa and bladygrass were grown together in nutrient culture. Caffeic, chlorogenic, isochloro-genic,p-coumaric,p-OH-benzoic, and ferulic acids were detected in alfalfa root exudates and residues. The highest amount (126 fig phenolic acids/g soil) of these compounds was found in alfalfa root residues after six months of decomposition in soil.

  18. ALFALFA: BIOFUEL AND FEED

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alfalfa hay is a major crop that supports Idaho's dairy industry. Several cellulosic feedstocks will be needed to meet current ethanol production goals. Alfalfa has considerable potential as a feedstock for production of ethanol and other industrial materials because of its high biomasss production...

  19. Plant Growth and Photosynthetic Characteristics of Mesembryanthemum crystallinum Grown Aeroponically under Different Blue- and Red-LEDs.

    PubMed

    He, Jie; Qin, Lin; Chong, Emma L C; Choong, Tsui-Wei; Lee, Sing Kong

    2017-01-01

    Mesembryanthemum crystallinum is a succulent, facultative crassulacean acid metabolism (CAM) plant. Plant growth and photosynthetic characteristics were studied when M. crystallinum plants were grown indoor under light emitting diodes (LED)-lighting with adequate water supply. Plants were cultured aeroponically for a 16-h photoperiod at an equal photosynthetic photon flux density of 350 μmol m(-2) s(-1) under different red:blue LED ratios: (1) 100:0 (0B); (2) 90:10 (10B); (3) 80:20 (20B); (4) 70:30 (30B); (5) 50:50 (50B); and (6)100:0 (100B). M. crystallinum grown under 10B condition had the highest shoot and root biomass and shoot/root ratio while those grown under 0B condition exhibited the lowest values. Compared to plants grown under 0B condition, all other plants had similar but higher total chlorophyll (Chl) and carotenoids (Car) contents and higher Chl a/b ratios. However, there were no significant differences in Chl/Car ratio among all plants grown under different red- and blue-LEDs. Photosynthetic light use efficiency measured by photochemical quenching, non-photochemical quenching, and electron transport rate, demonstrated that plants grown under high blue-LED utilized more light energy and had more effective heat dissipation mechanism compared to plants grown under 0B or lower blue-LED. Statistically, there were no differences in photosynthetic O2 evolution rate, light-saturated CO2 assimilation rate (Asat), and light-saturated stomatal conductance (gssat) among plants grown under different combined red- and blue-LEDs but they were significantly higher than those of 0B plants. No statistically differences in total reduced nitrogen content were found among all plants. For the total soluble protein, all plants grown under different combined red- and blue-LEDs had similar values but they were significantly higher than that of plants grown under 0B condition. However, plants grown under higher blue-LEDs had significant higher ribulose-1,5-bisphosphate

  20. Plant Growth and Photosynthetic Characteristics of Mesembryanthemum crystallinum Grown Aeroponically under Different Blue- and Red-LEDs

    PubMed Central

    He, Jie; Qin, Lin; Chong, Emma L. C.; Choong, Tsui-Wei; Lee, Sing Kong

    2017-01-01

    Mesembryanthemum crystallinum is a succulent, facultative crassulacean acid metabolism (CAM) plant. Plant growth and photosynthetic characteristics were studied when M. crystallinum plants were grown indoor under light emitting diodes (LED)-lighting with adequate water supply. Plants were cultured aeroponically for a 16-h photoperiod at an equal photosynthetic photon flux density of 350 μmol m-2 s-1 under different red:blue LED ratios: (1) 100:0 (0B); (2) 90:10 (10B); (3) 80:20 (20B); (4) 70:30 (30B); (5) 50:50 (50B); and (6)100:0 (100B). M. crystallinum grown under 10B condition had the highest shoot and root biomass and shoot/root ratio while those grown under 0B condition exhibited the lowest values. Compared to plants grown under 0B condition, all other plants had similar but higher total chlorophyll (Chl) and carotenoids (Car) contents and higher Chl a/b ratios. However, there were no significant differences in Chl/Car ratio among all plants grown under different red- and blue-LEDs. Photosynthetic light use efficiency measured by photochemical quenching, non-photochemical quenching, and electron transport rate, demonstrated that plants grown under high blue-LED utilized more light energy and had more effective heat dissipation mechanism compared to plants grown under 0B or lower blue-LED. Statistically, there were no differences in photosynthetic O2 evolution rate, light-saturated CO2 assimilation rate (Asat), and light-saturated stomatal conductance (gssat) among plants grown under different combined red- and blue-LEDs but they were significantly higher than those of 0B plants. No statistically differences in total reduced nitrogen content were found among all plants. For the total soluble protein, all plants grown under different combined red- and blue-LEDs had similar values but they were significantly higher than that of plants grown under 0B condition. However, plants grown under higher blue-LEDs had significant higher ribulose-1,5-bisphosphate

  1. Alfalfa non-feed uses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Non-feed uses for alfalfa such as biomass energy and phytoremediation could increase alfalfa acreage and improve farm profitability. The new bio-energy alfalfa and production system increased forage yield and ethanol production. New alfalfas with enhanced nitrogen cycling capacities would protect wa...

  2. ANTIOXIDANT ACTIVITY OF TISSUE CULTURE-RAISED BALLOTA NIGRA L. PLANTS GROWN EX VITRO.

    PubMed

    Makowczyńska, Joanna; Grzegorczyk-KAROLAK, Izabela; Wysokińska, Halina

    2015-01-01

    Antioxidant properties and total phenolic and flavonoid contents were evaluated in methanolic extracts of shoots from Ballota nigra plants initiated in vitro (from nodal explants) and in vivo (from seeds). The plants were grown in greenhouse and in the field, and were analyzed at the vegetative and flowering stages. The shoot extract of wild-grown plants of B. nigra was also investigated. The results indicate that antioxidant potential of the B. nigra extracts seems to be due to their scavenging of free radicals (DPPH assay) and metal reducing (FRAP test), while they were less effective at the prevention of linoleic acid peroxidation (LPO test). The extracts from shoots of in vitro derived plants were found to exhibit the greatest antioxidant properties. The extracts were also characterized by the highest content of phenolic compounds and their level was affected by plant developmental stage. The extracts of shoots collected at the flowering period exhibited higher amounts of phenolics and flavonoids than in the extracts of immature plants. A close correlation between the total phenolic content and flavonoid content and antioxidant activity using the DPPH and FRAP assays was obtained. The results of the present study suggest the use in vitro-derived plants of B. nigra instead of using wild plants for pharmaceutical purposes.

  3. Monoterpene and herbivore-induced emissions from cabbage plants grown at elevated atmospheric CO 2 concentration

    NASA Astrophysics Data System (ADS)

    Vuorinen, Terhi; Reddy, G. V. P.; Nerg, Anne-Marja; Holopainen, Jarmo K.

    The warming of the lower atmosphere due to elevating CO 2 concentration may increase volatile organic compound (VOC) emissions from plants. Also, direct effects of elevated CO 2 on plant secondary metabolism are expected to lead to increased VOC emissions due to allocation of excess carbon on secondary metabolites, of which many are volatile. We investigated how growing at doubled ambient CO 2 concentration affects emissions from cabbage plants ( Brassica oleracea subsp. capitata) damaged by either the leaf-chewing larvae of crucifer specialist diamondback moth ( Plutella xylostella L.) or generalist Egyptian cotton leafworm ( Spodoptera littoralis (Boisduval)). The emission from cabbage cv. Lennox grown in both CO 2 concentrations, consisted mainly of monoterpenes (sabinene, limonene, α-thujene, 1,8-cineole, β-pinene, myrcene, α-pinene and γ-terpinene). ( Z)-3-Hexenyl acetate, sesquiterpene ( E, E)- α-farnesene and homoterpene ( E)-4,8-dimethyl-1,3,7-nonatriene (DMNT) were emitted mainly from herbivore-damaged plants. Plants grown at 720 μmol mol -1 of CO 2 had significantly lower total monoterpene emissions per shoot dry weight than plants grown at 360 μmol mol -1 of CO 2, while damage by both herbivores significantly increased the total monoterpene emissions compared to intact plants. ( Z)-3-Hexenyl acetate, ( E, E)- α-farnesene and DMNT emissions per shoot dry weight were not affected by the growth at elevated CO 2. The emission of DMNT was significantly enhanced from plants damaged by the specialist P. xylostella compared to the plants damaged by the generalist S. littoralis. The relative proportions of total monoterpenes and total herbivore-induced compounds of total VOCs did not change due to the growth at elevated CO 2, while insect damage increased significantly the proportion of induced compounds. The results suggest that VOC emissions that are induced by the leaf-chewing herbivores will not be influenced by elevated CO 2 concentration.

  4. Advancements in Root Growth Measurement Technologies and Observation Capabilities for Container-Grown Plants

    PubMed Central

    Judd, Lesley A.; Jackson, Brian E.; Fonteno, William C.

    2015-01-01

    The study, characterization, observation, and quantification of plant root growth and root systems (Rhizometrics) has been and remains an important area of research in all disciplines of plant science. In the horticultural industry, a large portion of the crops grown annually are grown in pot culture. Root growth is a critical component in overall plant performance during production in containers, and therefore it is important to understand the factors that influence and/or possible enhance it. Quantifying root growth has varied over the last several decades with each method of quantification changing in its reliability of measurement and variation among the results. Methods such as root drawings, pin boards, rhizotrons, and minirhizotrons initiated the aptitude to measure roots with field crops, and have been expanded to container-grown plants. However, many of the published research methods are monotonous and time-consuming. More recently, computer programs have increased in use as technology advances and measuring characteristics of root growth becomes easier. These programs are instrumental in analyzing various root growth characteristics, from root diameter and length of individual roots to branching angle and topological depth of the root architecture. This review delves into the expanding technologies involved with expertly measuring root growth of plants in containers, and the advantages and disadvantages that remain. PMID:27135334

  5. Advancements in Root Growth Measurement Technologies and Observation Capabilities for Container-Grown Plants.

    PubMed

    Judd, Lesley A; Jackson, Brian E; Fonteno, William C

    2015-07-03

    The study, characterization, observation, and quantification of plant root growth and root systems (Rhizometrics) has been and remains an important area of research in all disciplines of plant science. In the horticultural industry, a large portion of the crops grown annually are grown in pot culture. Root growth is a critical component in overall plant performance during production in containers, and therefore it is important to understand the factors that influence and/or possible enhance it. Quantifying root growth has varied over the last several decades with each method of quantification changing in its reliability of measurement and variation among the results. Methods such as root drawings, pin boards, rhizotrons, and minirhizotrons initiated the aptitude to measure roots with field crops, and have been expanded to container-grown plants. However, many of the published research methods are monotonous and time-consuming. More recently, computer programs have increased in use as technology advances and measuring characteristics of root growth becomes easier. These programs are instrumental in analyzing various root growth characteristics, from root diameter and length of individual roots to branching angle and topological depth of the root architecture. This review delves into the expanding technologies involved with expertly measuring root growth of plants in containers, and the advantages and disadvantages that remain.

  6. Chloroplast avoidance movement is not functional in plants grown under strong sunlight.

    PubMed

    Higa, Takeshi; Wada, Masamitsu

    2016-04-01

    Chloroplast movement in nine climbing plant species was investigated. It is thought that chloroplasts generally escape from strong light to avoid photodamage but accumulate towards weak light to perform photosynthesis effectively. Unexpectedly, however, the leaves of climbing plants grown under strong sunlight showed very low or no chloroplast photorelocation responses to either weak or strong blue light when detected by red light transmittance through leaves. Direct observations of Cayratia japonica leaves, for example, revealed that the average number of chloroplasts in upper periclinal walls of palisade tissue cells was only 1.2 after weak blue-light irradiation and almost all of the chloroplasts remained at the anticlinal wall, the state of chloroplast avoidance response. The leaves grown under strong light have thin and columnar palisade tissue cells comparing with the leaves grown under low light. Depending on our analyses and our schematic model, the thinner cells in a unit leaf area have a wider total plasma membrane area, such that more chloroplasts can exist on the plasma membrane in the thinner cells than in the thicker cells in a unit leaf-area basis. The same strategy might be used in other plant leaves grown under direct sunlight.

  7. Metal uptake of tomato and alfalfa plants as affected by water source, salinity, and Cd and Zn levels under greenhouse conditions.

    PubMed

    Gharaibeh, Mamoun A; Marschner, Bernd; Heinze, Stefanie

    2015-12-01

    Irrigation with wastewater is a promising option to improve crop yields and to reduce pressure on freshwater sources. However, heavy metal concentrations in wastewater may cause health concerns. A greenhouse pot experiment was conducted in order to determine cadmium (Cd) and zinc (Zn) concentrations in sandy soil and plant tissues of tomato (Lycopersicon esculentum L.) and alfalfa (Medicago sativa L.). A 2 × 2 × 4 × 2 factorial treatment arrangement was utilized. Two water sources, fresh (FW) or treated wastewater (TWW), at two salinity levels (1 and 3 dS m(-1)) containing different levels of Cd and Zn were used. Samples were collected after a 90-day growth period. It was observed that the growth of both plants was depressed at the highest metal level (L3). Metal accumulation in plant parts increased with the increase of metal concentration and salinity in irrigation water. At low salinity, water source was the main factor which controlled metal accumulation, whereas, at high salinity, chloride appeared to be the principal factor controlling metal uptake regardless of water source. Metal translocation from roots to shoots increased in TWW-irrigated plants, even in the controls. Tomatoes accumulated Cd up to and above critical levels safe for human consumption, even though Cd concentration in irrigation water did not exceed the current recommended values. Therefore, food production in sandy soils may well pose a health hazard when irrigated with TWW containing heavy metals. Complexation with dissolved organic compounds (DOC) in TWW may be to be the principal factor responsible for increased metal uptake and transfer at low salinity, thereby increasing the risk of heavy metal contamination of food and forage crops.

  8. Comparative phytotoxicity of ZnO NPs, bulk ZnO, and ionic zinc onto the alfalfa plants symbiotically associated with Sinorhizobium meliloti in soil.

    PubMed

    Bandyopadhyay, Susmita; Plascencia-Villa, Germán; Mukherjee, Arnab; Rico, Cyren M; José-Yacamán, Miguel; Peralta-Videa, Jose R; Gardea-Torresdey, Jorge L

    2015-05-15

    ZnO nanoparticles (NPs) are reported as potentially phytotoxic in hydroponic and soil media. However, studies on ZnO NPs toxicity in a plant inoculated with bacterium in soil are limited. In this study, ZnO NPs, bulk ZnO, and ZnCl₂ were exposed to the symbiotic alfalfa (Medicago sativa L.)-Sinorhizobium meliloti association at concentrations ranging from 0 to 750 mg/kg soil. Plant growth, Zn bioaccumulation, dry biomass, leaf area, total protein, and catalase (CAT) activity were measured in 30 day-old plants. Results showed 50% germination reduction by bulk ZnO at 500 and 750 mg/kg and all ZnCl₂ concentrations. ZnO NPs and ionic Zn reduced root and shoot biomass by 80% and 25%, respectively. Conversely, bulk ZnO at 750 mg/kg increased shoot and root biomass by 225% and 10%, respectively, compared to control. At 500 and 750 mg/kg, ZnCl₂ reduced CAT activity in stems and leaves. Total leaf protein significantly decreased as external ZnCl₂ concentration increased. STEM-EDX imaging revealed the presence of ZnO particles in the root, stem, leaf, and nodule tissues. ZnO NPs showed less toxicity compared to ZnCl₂ and bulk ZnO found to be growth enhancing on measured traits. These findings are significant to reveal the toxicity effects of different Zn species (NPs, bulk, and ionic Zn) into environmentally important plant-bacterial system in soil.

  9. Stress Responses in Alfalfa (Medicago sativa L.)

    PubMed Central

    Gowri, Ganesan; Bugos, Robert C.; Campbell, Wilbur H.; Maxwell, Carl A.; Dixon, Richard A.

    1991-01-01

    S-Adenosyl-l-methionine:caffeic acid 3-O-methyltransferase (COMT, EC 2.1.1.6) catalyzes the conversion of caffeic acid to ferulic acid, a key step in the biosynthesis of lignin monomers. We have isolated a functionally active cDNA clone (pCOMT1) encoding alfalfa (Medicago sativa L.) COMT by immunoscreening a λZAPII cDNA expression library with anti-(aspen COMT) antibodies. The derived amino acid sequence of pCOMT1 is 86% identical to that of COMT from aspen. Southern blot analysis indicates that COMT in alfalfa is encoded by at least two genes. Addition of an elicitor preparation from bakers' yeast to alfalfa cell suspension cultures resulted in a rapid accumulation of COMT transcripts, which reached a maximum level around 19 hours postelicitation. Northern blot analysis of total RNA from different organs of alfalfa plants at various developmental stages showed that COMT transcripts are most abundant in roots and stems. Transcripts encoding ATP: i-methionine-S-adenosyl transferase (AdoMet synthetase, EC 2.5.1.6), the enzyme responsible for the synthesis of the methyl donor for the COMT reaction, were coinduced with COMT transcripts in elicitor-treated cells and exhibited a similar pattern of expression to that of COMT in different organs of alfalfa plants at various stages of development. ImagesFigure 3Figure 4Figure 6 PMID:16668418

  10. Toxic effects of copper-based nanoparticles or compounds to lettuce (Lactuca sativa) and alfalfa (Medicago sativa).

    PubMed

    Hong, Jie; Rico, Cyren M; Zhao, Lijuan; Adeleye, Adeyemi S; Keller, Arturo A; Peralta-Videa, Jose R; Gardea-Torresdey, Jorge L

    2015-01-01

    The increased production and use of nanoparticles (NPs) has generated concerns about their impact on living organisms. In this study, nCu, bulk Cu, nCuO, bulk CuO, Cu(OH)2 (CuPRO 2005, Kocide 3000), and CuCl2 were exposed for 15 days to 10 days-old hydroponically grown lettuce (Lactuca sativa) and alfalfa (Medicago sativa). Each compound was applied at 0, 5, 10, and 20 mg L(-1). At harvest, we measured the size of the plants and determined the concentration of Cu, macro and microelements by using ICP-OES. Catalase and ascorbate peroxidase activity was also determined. Results showed that all Cu NPs/compounds reduced the root length by 49% in both plant species. All Cu NPs/compounds increased Cu, P, and S (>100%, >50%, and >20%, respectively) in alfalfa shoots and decreased P and Fe in lettuce shoot (>50% and >50%, respectively, excluding Fe in CuCl2 treatment). Biochemical assays showed reduced catalase activity in alfalfa (root and shoot) and increased ascorbate peroxidase activity in roots of both plant species. Results suggest that Cu NPs/compounds not only reduced the size of the plants but altered nutrient content and enzyme activity in both plant species.

  11. Toxic Effects of Copper-based Nanoparticles or Compounds to Lettuce (Lactuca sativa) and Alfalfa (Medicago sativa)

    PubMed Central

    Hong, Jie; Rico, Cyren; Zhao, Lijuan; Adeleye, Adeyemi S.; Keller, Arturo A.; Peralta-Videa, Jose R.; Gardea-Torresdey, Jorge L.

    2014-01-01

    The increased production and use of nanoparticles (NPs) has generated concerns about their impact on living organisms. In this study, nCu, bulk Cu, nCuO, bulk CuO, Cu(OH)2 (CuPRO 2005, Kocide 3000), and CuCl2 were exposed for 15 days to 10 day-old hydroponically grown lettuce (Lactuca sativa) and alfalfa (Medicago sativa). Each compound was applied at 0, 5, 10, and 20 mg/L. At harvest, we measured the size of the plants and determined the concentration of Cu, macro and microelements by using ICP-OES. Catalase and ascorbate peroxidase activity was also determined. Results showed that all Cu NPs/compounds reduced the root length by 49% in both plant species. All Cu NPs/compounds increased Cu, P, and S (>100%, >50%, and >20%, respectively) in alfalfa shoots and decreased P and Fe in lettuce shoot (>50% and >50%, respectively, excluding Fe in CuCl2 treatment). Biochemical assays showed reduced catalase activity in alfalfa (root and shoot) and increased ascorbate peroxidase activity in roots of both plant species. Results suggest that Cu NPs/compounds not only reduced the size of the plants but altered nutrient content and enzyme activity in both plant species. PMID:25474419

  12. Enhanced tolerance and remediation to mixed contaminates of PCBs and 2,4-DCP by transgenic alfalfa plants expressing the 2,3-dihydroxybiphenyl-1,2-dioxygenase.

    PubMed

    Wang, Yan; Ren, Hejun; Pan, Hongyu; Liu, Jinliang; Zhang, Lanying

    2015-04-09

    Polychlorinated biphenyls (PCBs) and 2,4-dichlorophenol (2,4-DCP) generally led to mixed contamination of soils as a result of commercial and agricultural activities. Their accumulation in the environment poses great risks to human and animal health. Therefore, the effective strategies for disposal of these pollutants are urgently needed. In this study, genetic engineering to enhance PCBs/2,4-DCP phytoremediation is a focus. We cloned the 2,3-dihydroxybiphenyl-1,2-dioxygenase (BphC.B) from a soil metagenomic library, which is the key enzyme of aerobic catabolism of a variety of aromatic compounds, and then it was expressed in alfalfa driven by CaMV 35S promoter using Agrobacterium-mediated transformation. Transgenic line BB11 was selected out through PCR, Western blot analysis and enzyme activity assays. Its disposal and tolerance to both PCBs and 2,4-DCP were examined. The tolerance capability of transgenic line BB11 towards complex contaminants of PCBs/2,4-DCP significantly increased compared with non-transgenic plants. Strong dissipation of PCBs and high removal efficiency of 2,4-DCP were exhibited in a short time. It was confirmed expressing BphC.B would be a feasible strategy to help achieving phytoremediation in mixed contaminated soils with PCBs and 2,4-DCP.

  13. Environmental Stresses Increase Photosynthetic Disruption by Metal Oxide Nanomaterials in a Soil-Grown Plant.

    PubMed

    Conway, Jon R; Beaulieu, Arielle L; Beaulieu, Nicole L; Mazer, Susan J; Keller, Arturo A

    2015-12-22

    Despite an increasing number of studies over the past decade examining the interactions between plants and engineered nanomaterials (ENMs), very few have investigated the influence of environmental conditions on ENM uptake and toxicity, particularly throughout the entire plant life cycle. In this study, soil-grown herbaceous annual plants (Clarkia unguiculata) were exposed to TiO2, CeO2, or Cu(OH)2 ENMs at different concentrations under distinct light and nutrient levels for 8 weeks. Biweekly fluorescence and gas exchange measurements were recorded, and tissue samples from mature plants were analyzed for metal content. During peak growth, exposure to TiO2 and CeO2 decreased photosynthetic rate and CO2 assimilation efficiency of plants grown under high light and nutrient conditions, possibly by disrupting energy transfer from photosystem II (PSII) to the Calvin cycle. Exposure Cu(OH)2 particles also disrupted photosynthesis but only in plants grown under the most stressful conditions (high light, limited nutrient) likely by preventing the oxidation of a primary PSII reaction center. TiO2 and CeO2 followed similar uptake and distribution patterns with concentrations being highest in roots followed by leaves then stems, while Cu(OH)2 was present at highest concentrations in leaves, likely as ionic Cu. ENM accumulation was highly dependent on both light and nutrient levels and a predictive regression model was developed from these data. These results show that abiotic conditions play an important role in mediating the uptake and physiological impacts of ENMs in terrestrial plants.

  14. Rhizobacterial Community Structures Associated with Native Plants Grown in Chilean Extreme Environments.

    PubMed

    Jorquera, Milko A; Maruyama, Fumito; Ogram, Andrew V; Navarrete, Oscar U; Lagos, Lorena M; Inostroza, Nitza G; Acuña, Jacquelinne J; Rilling, Joaquín I; de La Luz Mora, María

    2016-10-01

    Chile is topographically and climatically diverse, with a wide array of diverse undisturbed ecosystems that include native plants that are highly adapted to local conditions. However, our understanding of the diversity, activity, and role of rhizobacteria associated with natural vegetation in undisturbed Chilean extreme ecosystems is very poor. In the present study, the combination of denaturing gradient gel electrophoresis and 454-pyrosequencing approaches was used to describe the rhizobacterial community structures of native plants grown in three representative Chilean extreme environments: Atacama Desert (ATA), Andes Mountains (AND), and Antarctic (ANT). Both molecular approaches revealed the presence of Proteobacteria, Bacteroidetes, and Actinobacteria as the dominant phyla in the rhizospheres of native plants. Lower numbers of operational taxonomic units (OTUs) were observed in rhizosphere soils from ATA compared with AND and ANT. Both approaches also showed differences in rhizobacterial community structures between extreme environments and between plant species. The differences among plant species grown in the same environment were attributed to the higher relative abundance of classes Gammaproteobacteria and Alphaproteobacteria. However, further studies are needed to determine which environmental factors regulate the structures of rhizobacterial communities, and how (or if) specific bacterial groups may contribute to the growth and survival of native plants in each Chilean extreme environments.

  15. Mercury uptake and translocation in Impatiens walleriana plants grown in the contaminated soil from Oak Ridge.

    PubMed

    Pant, P; Allen, M; Tansel, B

    2011-02-01

    Mercury (Hg) contaminated soils from Oak Ridge, Tennessee were investigated for phytoavailability of mercury as measured by degree of Hg translocation in aboveground biomass of Impatiens walleriana plants grown in the soils. After 90 days of incubation, results revealed a higher concentration of total Hg in the leaves than in the flowers or the stems. Plants that were grown in the soils with higher Hg concentrations showed significantly higher Hg uptake and translocation in the aboveground plant-biomass, and the correlation with the initial soil-Hg was significant for the leaves and the stems in the plants that were tested. On an average, only 4.06 microg of Hg could be found in the above ground plant biomass of all the plants, compared to an average 3673.50 microg of initial total Hg concentrations in these soils. Statistical analysis revealed a greater affinity of Hg for the soil carbon, which supported the finding of this study on low soil Hg bioavailability.

  16. [Accumulation of magnetic nanoparticles in plants grown on soils of Apsheron peninsula].

    PubMed

    Khalilov, R I; Nasibova, A N; Serezhenkov, V A; Ramazanov, M A; Kerimov, M K; Garibov, A A; Vanin, A F

    2011-01-01

    The disclosure of magnetic nanoparticles in five plant species growing in Apsheron peninsula have been detected by the EPR method. The EPR spectra of these nanoparticles proved to be similar to those of synthesized magnetic nanoparticles. The result demonstrated that plants are capable of absorbing magnetic nanoparticles from the soil. The accumulation of nanoparticles in plants is confirmed by the presence of a broad EPR signal whose maximum position of the low-field component changes from g = 2.38 and halfwidth of the signal of 32 mT at room temperature to g = 2.71 and 50-55 mT at 80 K. The intensity of the broad EPR signal for plants grown in radioactively contaminated areas (170-220 mkR per h) was substantially lower compared with plants grown on clean soil. The parameters of the broad EPR signal and its dependence on the temperature of recording were identical with those for synthetic magnetic nanoparticles. The photosynthetic activity and changes in the genome of irradiated plants by the analysis of PCR products were studied.

  17. Rapid phenotyping of alfalfa root system architecture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Root system architecture (RSA) influences the capacity of an alfalfa plant for symbiotic nitrogen fixation, nutrient uptake and water use efficiency, resistance to frost heaving, winterhardiness, and some pest and pathogen resistance. However, we currently lack a basic understanding of root system d...

  18. Alfalfa interseeded into silage corn can serve as a cover crop and subsequent forage crop

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alfalfa (Medicago sativa) and corn (Zea mays) silage are commonly grown in rotation in dairy forage production systems throughout the northern regions of the USA. Alfalfa interseeded into silage corn could potentially serve two purposes: as a cover crop during the silage corn production year, and as...

  19. First report of race 2 of Colletotrichum trifolii causing anthracnose on alfalfa (Medicago sativa) in Wisconsin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Anthracnose of alfalfa (Medicago sativa), caused by Colletotrichum trifolii, is widespread in the United States. Three physiological races have been described. Race 1 is reported to be the dominant race that is present wherever alfalfa is grown, while race 2 was reported in a limited area in the Mid...

  20. Diversity of the exoproteome of Fusarium graminearum grown on plant cell wall.

    PubMed

    Phalip, Vincent; Delalande, François; Carapito, Christine; Goubet, Florence; Hatsch, Didier; Leize-Wagner, Emmanuelle; Dupree, Paul; Dorsselaer, Alain Van; Jeltsch, Jean-Marc

    2005-12-01

    The exoproteome of the fungus Fusarium graminearum grown on glucose and on hop (Humulus lupulus, L.) cell wall has been investigated. The culture medium was found to contain a higher quantity of proteins and the proteins are more diverse when the fungus is grown on cell wall. Using both 1D and 2D electrophoresis followed by mass spectrometry analysis and protein identification based on similarity searches, 84 unique proteins were identified in the cell wall-grown fungal exoproteome. Many are putatively implicated in carbohydrate metabolism, mainly in cell wall polysaccharide degradation. The predicted carbohydrate-active enzymes fell into 24 different enzymes classes, and up to eight different proteins within a same class are secreted. This indicates that fungal metabolism becomes oriented towards synthesis and secretion of a whole arsenal of enzymes able to digest almost the complete plant cell wall. Cellobiohydrolase is one of the only four proteins found both after growth on glucose and on plant cell wall and we propose that this enzyme could act as a sensor of the extracellular environment. Extensive knowledge of this very diverse F. graminearum exoproteome is an important step towards the full understanding of Fusarium/plants interactions.

  1. Composition of volatile in micropropagated and field grown aromatic plants from Tuscany Islands.

    PubMed

    Pistelli, Laura; Noccioli, Cecilia; D'Angiolillo, Francesca; Pistelli, Luisa

    2013-01-01

    Aromatic plant species present in the natural Park of Tuscany Archipelago are used as flavoring agents and spices, as dietary supplements and in cosmetics and aromatherapy. The plants are usually collected from wild stands, inducing a depletion of the natural habitat. Therefore, micropropagation of these aromatic plants can play a role in the protection of the natural ecosystem, can guarantee a massive sustainable production and can provide standardized plant materials for diverse economical purposes. The aim of this study is to compare the volatile organic compounds produced by the wild plants with those from in vitro plantlets using headspace solid phase micro-extraction (HS-SPME) followed by capillary gas-chromatography coupled to mass spectrometry (GC-MS). Typical plants of this natural area selected for this work were Calamintha nepeta L., Crithmum maritimum L., Lavandula angustifolia L., Myrtus communis L., Rosmarinus officinalis L., Salvia officinalis L. and Satureja hortensis L. Different explants were used: microcuttings with vegetative apical parts, axillary buds and internodes. Sterilization percentage, multiplication rate and shoot length, as well as root formation were measured. The volatile aromatic profiles produced from in vitro plantlets were compared with those of the wild plants, in particular for C. maritimum, R. officinalis, S. officinalis and S. hortensis. This study indicated that the micropropagation technique can represent a valid alternative to produce massive and sterile plant material characterised by the same aromatic flavour as in the wild grown plants.

  2. Irrigation frequency alters nutrient uptake in container-grown Rhododendron plants grown with different rates of nitrogen

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The influence of irrigation frequency (same amount of water per day given at different times) on nutrient uptake of container-grown evergreen Rhododendron ‘P.J.M. Compact’ (PJM) and ‘English Roseum’ (ER) and deciduous Rhododendron ‘Gibraltar’ (AZ) grown with different rates of nitrogen (N) fertilize...

  3. The relationship between growth and soluble sugar concentration of Aloe vera plants grown under three levels of irradiance

    SciTech Connect

    Paez, A.; Gebre, G.M.; Tschaplinski, T.J. )

    1994-06-01

    The CAM plant Aloe vera was vegetatively propagated and grown under three irradiances: full sun, partial and deep shade (30% and 10% of ambient light, respectively) to determine the effect on growth, biomass allocation, and sugar concentration. After one year, the plants were harvested to determine final dry weight and the sugar concentration of the leaf mucilaginous gel. Plants grown under full sun produced twice the total dry weight of those grown under partial shade, with the difference equally partitioned between the shoot and root. Plants grown under full sun also produced thicker leaves, and more numerous and large auxiliary shoots. The dry weight of plants grown under deep shade was 8.6% that of plants grown under full sun, which was directly proportional to the irradiance received. Partial shade increased the number and length of leaves produced on the primary shoot, but the allocation of carbon to roots was the lowest of all treatments. Partial shade reduced the total sugar concentration of the leaf gel matrix to 34% that of plants under full sun, due to reductions in all sugars measured. Glucose was the most abundant soluble sugar, with its relative contribution to the total pool increasing under shade. In summary, the proportional effects of partial shading were greater on soluble sugar concentrations than on the total plant biomass produced.

  4. Tolerance of wheat and lettuce plants grown on human mineralized waste to high temperature stress

    NASA Astrophysics Data System (ADS)

    Ushakova, Sofya A.; Tikhomirov, Alexander A.; Shikhov, Valentin N.; Gros, Jean-Bernard; Golovko, Tamara K.; Dal'ke, Igor V.; Zakhozhii, Ilya G.

    2013-06-01

    The main objective of a life support system for space missions is to supply a crew with food, water and oxygen, and to eliminate their wastes. The ultimate goal is to achieve the highest degree of closure of the system using controlled processes offering a high level of reliability and flexibility. Enhancement of closure of a biological life support system (BLSS) that includes plants relies on increased regeneration of plant waste, and utilization of solid and liquid human wastes. Clearly, the robustness of a BLSS subjected to stress will be substantially determined by the robustness of the plant components of the phototrophic unit. The aim of the present work was to estimate the heat resistance of two plants (wheat and lettuce) grown on human wastes. Human exometabolites mineralized by hydrogen peroxide in an electromagnetic field were used to make a nutrient solution for the plants. We looked for a possible increase in the heat tolerance of the wheat plants using changes in photosynthetically active radiation (PAR) intensity during heat stress. At age 15 days, plants were subjected to a rise in air temperature (from 23 ± 1 °C to 44 ± 1 °С) under different PAR intensities for 4 h. The status of the photosynthetic apparatus of the plants was assessed by external СО2 gas exchange and fluorescence measurements. The increased irradiance of the plants during the high temperature period demonstrated its protective action for both the photosynthetic apparatus of the leaves and subsequent plant growth and development. The productivity of the plants subjected to temperature changes at 250 W m-2 of PAR did not differ from that of controls, whereas the productivity of the plants subjected to the same heat stress but in darkness was halved.

  5. Animal feed compositions containing phytase derived from transgenic alfalfa and methods of use thereof

    SciTech Connect

    Austin-Phillips, Sandra; Koegel, Richard G.; Straub, Richard J.; Cook, Mark

    1999-01-01

    A value-added composition of matter containing plant matter from transgenic alfalfa which expresses exogenous phytase activity is disclosed. The phytase activity is a gene product of an exogenous gene encoding for phytase which has been stably incorporated into the genome of alfalfa plants. The transgenic alfalfa expresses phytase activity in nutritionally-significant amounts, thereby enabling its use in animal feeds to eliminate the need for phosphorous supplementation of livestock, poultry, and fish feed rations.

  6. Animal feed compositions containing phytase derived from transgenic alfalfa and methods of use thereof

    DOEpatents

    Austin-Phillips, Sandra; Koegel, Richard G.; Straub, Richard J.; Cook, Mark

    2001-01-01

    A value-added composition of matter containing plant matter from transgenic alfalfa which expresses exogenous phytase activity is disclosed. The phytase activity is a gene product of an exogenous gene encoding for phytase which has been stably incorporated into the genome of alfalfa plants. The transgenic alfalfa expresses phytase activity in nutritionally-significant amounts, thereby enabling its use in animal feeds to eliminate the need for phosphorous supplementation of livestock, poultry, and fish feed rations.

  7. High relative humidity increases yield, harvest index, flowering, and gynophore growth of hydroponically grown peanut plants

    NASA Technical Reports Server (NTRS)

    Mortley, D. G.; Bonsi, C. K.; Loretan, P. A.; Hill, W. A.; Morris, C. E.

    2000-01-01

    Growth chamber experiments were conducted to study the physiological and growth response of peanut (Arachis hypogaea L.) to 50% and 85% relative humidity (RH). The objective was to determine the effects of RH on pod and seed yield, harvest index, and flowering of peanut grown by the nutrient film technique (NFT). 'Georgia Red' peanut plants (14 days old) were planted into growth channels (0.15 x 0.15 x 1.2 m). Plants were spaced 25 cm apart with 15 cm between channels. A modified half-Hoagland solution with an additional 2 mM Ca was used. Solution pH was maintained between 6.4 and 6.7, and electrical conductivity (EC) ranged between 1100 and 1200 microS cm-1. Temperature regimes of 28/22 degrees C were maintained during the light/dark periods (12 hours each) with photosynthetic photon flux (PPF) at canopy level of 500 micromoles-m-2s-1. Foliage and pod fresh and dry weights, total seed yield, harvest index (HI), and seed maturity were greater at high than at low RH. Plants grown at 85% RH had greater total and individual leaflet area and stomatal conductance, flowered 3 days earlier and had a greater number of flowers reaching anthesis. Gynophores grew more rapidly at 85% than at 50% RH.

  8. Lignification in young plant seedlings grown on earth and aboard the Space Shuttle

    NASA Technical Reports Server (NTRS)

    Cowles, Joe R.; Lemay, R.; Jahns, G.; Scheld, W. H.; Peterson, C.

    1989-01-01

    The Space Shuttle era has provided an opportunity for investigators to conduct experiments in a microgravity environment. Two Shuttle flights, STS-3 and STS-51F, each contained an experiment designed principally to determine whether young plant seedlings exposed to microgravity had reduced lignin content in comparison to seedlings grown at one gravity. Three different plant species, pine, oats, and mung beans, were exposed for eight days to the microgravity environment of the Shuttle. The lignin content of in-flight seedlings was less than the control seedlings in all seven sets of seedlings included in these two experiments. In five sets of seedlings, the reduction in lignin content in flight seedlings ranged from 6 to 24 percent and was statistically significant. In addition, the activity of two enzymes involved in lignin synthesis, phenylalanine ammonia lyase and peroxidase, were significantly reduced in pine seedlings. It was therefore concluded that microgravity, as perceived by young plant seedlings, results in reduced lignin synthesis.

  9. Characteristics of cannabinoids composition of Cannabis plants grown in Northern Thailand and its forensic application.

    PubMed

    Tipparat, Prapatsorn; Natakankitkul, Surapol; Chamnivikaipong, Pipop; Chutiwat, Sirot

    2012-02-10

    The Thai government has recognized the possibility for legitimate cultivation of hemp. Further study of certain cannabinoid characteristics is necessary in establishing criteria for regulation of cannabis cultivation in Thailand. For this purpose, factors affecting characteristics of cannabinoids composition of Thai-grown cannabis were investigated. Plants were cultivated from seeds derived from the previous studies under the same conditions. 372 cannabis samples from landraces, three different trial fields and seized marijuana were collected. 100g of each sample was dried, ground and quantitatively analyzed for THC, CBD and CBN contents by GC-FID. The results showed that cannabis grown during March-June which had longer vegetative stages and longer photoperiod exposure, had higher cannabinoids contents than those grown in August. The male plants grown in trial fields had the range of THC contents from 0.722% to 0.848% d.w. and average THC/CBD ratio of 1.9. Cannabis in landraces at traditional harvest time of 75 days had a range of THC contents from 0.874% to 1.480% d.w. and an average THC/CBD ratio of 2.6. The THC contents and THC/CBD ratios of cannabis in second generation crops grown in the same growing season were found to be lower than those grown in the first generation, unless fairly high temperatures and a lesser amount of rainfall were present. The average THC content in seized fresh marijuana was 2.068% d.w. while THC/CBD ratios were between 12.6 and 84.09, which is 10-45 times greater than those of similar studied cannabis samples from the previous study. However, most Thai cannabis in landraces and in trial fields giving a low log(10) value of THC/CBD ratio at below 1 may be classified as intermediate type, whereas seized marijuana giving a higher log(10) value at above 1 could be classified as drug type. Therefore, the expanded information provided by the current study will assist in the development of criteria for regulation of hemp cultivation in

  10. Relationship of crop radiance to alfalfa agronomic values

    NASA Technical Reports Server (NTRS)

    Tucker, C. J.; Elgin, J. H., Jr.; Mcmurtrey, J. E., III

    1980-01-01

    Red and photographic infrared spectral data of alfalfa were collected at the time of the third and fourth cuttings using a hand-held radiometer for the earlier alfalfa cutting. Significant linear and non-linear correlation coefficients were found between the spectral variables and plant height, biomass, forage water content, and estimated canopy cover. For the alfalfa of the later cutting, which had experienced a period of severe drought stress which limited growth, the spectral variables were found to be highly correlated with the estimated drought scores.

  11. Antioxidant response in sesame plants grown on industrially contaminated soil: effect on oil yield and tolerance to lipid peroxidation.

    PubMed

    Gupta, Amit K; Sinha, Sarita

    2009-01-01

    The plants of sesame white (Sesamum indicum L. var. T55) grown on tannery sludge (TS) contaminated soil have shown that Cr level in the seeds was found below detection limits in 10% and 25% TS, however, the levels of Ni, Pb and Cd were found above the recommended limits. In roots, the level of antioxidants increased in the plants grown upto 35% TS at 30d over their respective controls. Total chlorophyll content increased significantly (p<0.5) in the plants (leaves) grown on lower sludge amendments (upto 35% TS at 30d and 25% TS at 60d) over their respective controls. In addition, the oil content increased (35% increase over control) in the plants grown on 35% TS. No significant change was observed in thiobarbituric acid reactive substances (TBARS), a lipid peroxidation index, in the plants (upto 50% TS). The number of trichomes in the leaves of treated plants was found more than control. In lower and upper leaves surfaces, the anterior end of the trichomes was found acute tipped and bent downwards, whereas, the trichome tip was straight and blunt in control. The stomata on upper and lower surfaces of the leaves were found partially or totally closed in the plants grown on 100% TS as compared to control. The toxicity was observed at higher amendments which are evident from the observed morphological changes and decrease in chlorophyll content. This study concludes that it is not advisable to grow the plants on contaminated area, besides its healthy growth.

  12. The Undergraduate ALFALFA Team

    NASA Astrophysics Data System (ADS)

    Koopmann, Rebecca A.; Higdon, S.; Balonek, T. J.; Haynes, M. P.; Giovanelli, R.

    2010-01-01

    The Undergraduate ALFALFA (Arecibo Legacy Fast ALFA) Team is a consortium of 16 institutions engaged in an NSF-sponsored program to promote undergraduate research within the extragalactic ALFALFA HI blind survey project. In the first two years of the program, more than three dozen undergraduate students have been closely involved in ALFALFA science, observing, and data analysis. A total of 34 students have attended the annual undergraduate workshops at Arecibo Observatory, interacting with faculty, their peers, ALFALFA experts, and Arecibo staff in lectures, group activities, tours, and observing runs. Team faculty have supervised 26 summer research projects and 14 academic year (e.g., senior thesis) projects. Students and faculty have traveled to Arecibo Observatory for observing runs and to national meetings to present their results. Eight Team schools have joined to work collaboratively to analyze HI properties of galaxy groups within the ALFALFA volume. (See O'Brien et al., O'Malley et al., and Odekon et al. posters, this meeting.) Students involved in this program are learning how science is accomplished in a large collaboration while contributing to the scientific goals of a major legacy survey. This work has been supported by NSF grants AST-0724918, AST-0725267, and AST-0725380.

  13. Uptake of trichloroethylene by hybrid poplar trees grown hydroponically in flow-through plant growth chambers

    SciTech Connect

    Orchard, B.J.; Doucette, W.J.; Chard, J.K.; Bugbee, B.

    2000-04-01

    Phytoremediation in being promoted as a cost-effective treatment option for shallow groundwater and soils contaminated with trichloroethylene (TCE). However, its effectiveness is difficult to assess due to contradictory reports regarding the magnitude of plant uptake and phytovolatilization. Experimental artifacts and plants stress, resulting from the use of static or low-flow plants growth laboratory systems, may account for part of the discrepancy. High exposure concentrations and short durations may also cause artifacts in laboratory studies. A dual-chamber plant growth system designed to minimize experimental artifacts was used to determine the uptake of [{sup 14}C] TCE by hydroponically grown hybrid poplar as a function of plant stress, exposure concentration, and exposure duration. The [{sup 14}]TCE recoveries ranged from 92 to 101% in 11 dosed chambers. Trichloroethylene mass equivalent concentrations in the shoot tissue were dependent on the amount of water transpired and the exposure concentration. Root-zone oxygen status die not significantly impact TCE uptake. Transpiration stream concentration factors (TSCFs) determined in these studies were independent of exposure duration and are much lower than those previously reported and predicted. The role of TSCF and other factors in estimating the significance of plant uptake in the phytoremediation of TCE-contaminated groundwater is discussed.

  14. Nitrogen fertilizer improves boron phytoextraction by Brassica juncea grown in contaminated sediments and alleviates plant stress.

    PubMed

    Giansoldati, Virginia; Tassi, Eliana; Morelli, Elisabetta; Gabellieri, Edi; Pedron, Francesca; Barbafieri, Meri

    2012-06-01

    In this study we evaluated the effect of different fertilizer treatments on Brassica plants grown on boron-contaminated sediments. Experiments were conducted in the laboratory and on the lysimeter scale. At laboratory scale (microcosm), five different fertilizers were tested for a 35-d period. On the lysimeter scale, nitrogen fertilization was tested at three different doses and plants were allowed to grow until the end of the vegetative phase (70 d). Results showed that nitrogen application had effectively increased plant biomass production, while B uptake was not affected. Total B phytoextracted increased three-fold when the highest nitrogen dose was applied. Phytotoxicity on Brassica was evaluated by biochemical parameters. In plants grown in unfertilized B-contaminated sediments, the activity of antioxidant enzymes superoxide dismutase (SOD), ascorbate peroxidase (APX) and pyrogallol peroxidase (PPX) increased, whereas catalase (CAT) decreased with respect to control plants. Addition of N progressively mitigated the alteration of enzymatic activity, thus suggesting that N can aid in alleviating B-induced oxidative stress. SOD activity was restored to control levels just at the lowest N treatment, whereas the CAT inhibition was partially restored only at the highest one. N application also lowered the B-induced increase in APX and PPX activities. Increased glutathione reductase activity indicated the need to restore the oxidative balance of glutathione. Data also suggest a role of glutathione and phytochelatins in B defense mechanisms. Results suggest that the nitrogen fertilizer was effective in improving B phytoextraction by increasing Brassica biomass and by alleviating B-induced oxidative stress.

  15. Mycoleptodiscus Crown and Root Rot of Alfalfa: An Emerging Problem in Minnesota and Wisconsin?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mycoleptodiscus crown and root rot was observed on alfalfa plants from southeastern MN and southwestern WI during the summer of 2009. The disease was observed in new plantings and established stands. Although the disease has been known since the 1950's, it has not caused severe problems in alfalfa p...

  16. Roadside alfalfa: Innocent bystanders or conveyers of genetically-engineered traits?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Clumps of alfalfa are a common sight along roads and vacant lots in areas that grow alfalfa for hay or seed. So what role do feral roadside plants play in dispersing transgenes? Is there a risk that transgenic feral plants serve as reservoirs or conduits that might facilitate the movement of transg...

  17. Phytohormone profile in Lactuca sativa and Brassica oleracea plants grown under Zn deficiency.

    PubMed

    Navarro-León, Eloy; Albacete, Alfonso; Torre-González, Alejandro de la; Ruiz, Juan M; Blasco, Begoña

    2016-10-01

    Phytohormones, structurally diverse compounds, are involved in multiple processes within plants, such as controlling plant growth and stress response. Zn is an essential micronutrient for plants and its deficiency causes large economic losses in crops. Therefore, the purpose of this study was to analyse the role of phytohormones in the Zn-deficiency response of two economically important species, i.e. Lactuca sativa and Brassica oleracea. For this, these two species were grown hydroponically with different Zn-application rates: 10 μM Zn as control and 0.1 μM Zn as deficiency treatment and phytohormone concentration was determined by U-HPLC-MS. Zn deficiency resulted in a substantial loss of biomass in L. sativa plants that was correlated with a decline in growth-promoting hormones such as indole-3-acetic acid (IAA), cytokinins (CKs), and gibberellins (GAs). However these hormones increased or stabilized their concentrations in B. oleracea and could help to maintain the biomass in this species. A lower concentration of stress-signaling hormones such as ethylene precursor aminocyclopropane-1-carboxylic acid (ACC), abscisic acid (ABA), salicylic acid (SA) and jasmonic acid (JA) and also CKs might be involved in Zn uptake in L. sativa while a rise in GA4, isopentenyl adenine (iP), and ACC and a fall in JA and SA might contribute to a better Zn-utilization efficiency (ZnUtE), as observed in B. oleracea plants.

  18. Health status of alfalfa leafcutting bee larvae (Hymenoptera: Megachilidae) in United States alfalfa seed fields.

    PubMed

    James, R R; Pitts-Singer, T L

    2013-12-01

    We conducted a broad geographic survey in the northwestern United States to quantify production losses in the alfalfa leafcutting bee (Megachile rotundata (F.), Hymenoptera: Megachilidae), a solitary pollinator used extensively in alfalfa seed production. Viable larvae were found in only 47.1% of the nest cells collected at the end of the season. Most of the rest of the cells contained pollen balls (typified by a provision but no larva; 16.7%), unknown causes of mortality (15.5%), or larvae killed by chalkbrood (8.0%). Prevalence of pollen balls was correlated positively with bee release rates and negatively with alfalfa stand age. The unknown mortality was correlated with the U.S. Department of Agriculture-Plant Hardiness Zone, and thus, some of the mortality may be caused by high temperature extremes, although the nesting season degree-days were not correlated with this mortality. Chalkbrood prevalence was correlated with possible nesting-resource or crowding-related factors, such as the number of bees released per hectare and the number of shelters used, but not with nesting board disinfection practices. Vapona is used to control parasitoids when the parent bees are incubated before release, and use of this fumigant was associated with an increase in both chalkbrood and diapausing offspring, although any reason for these correlations are unknown. This survey quantifies the variation in the quality of alfalfa leafcutting bee cocoons produced across much of the U.S. alfalfa seed production area.

  19. Wool-waste as organic nutrient source for container-grown plants

    SciTech Connect

    Zheljazkov, Valtcho D. Stratton, Glenn W.; Pincock, James; Butler, Stephanie; Jeliazkova, Ekaterina A.; Nedkov, Nedko K.; Gerard, Patrick D.

    2009-07-15

    A container experiment was conducted to test the hypothesis that uncomposted wool wastes could be used as nutrient source and growth medium constituent for container-grown plants. The treatments were: (1) rate of wool-waste application (0 or unamended control, 20, 40, 80, and 120 g of wool per 8-in. pot), (2) growth medium constituents [(2.1) wool plus perlite, (2.2) wool plus peat, and (2.3) wool plus peat plus perlite], and (3) plant species (basil and Swiss chard). A single addition of 20, 40, 80, or 120 g of wool-waste to Swiss chard (Beta vulgaris L.) and basil (Ocimum basilicum L.) in pots with growth medium provided four harvests of Swiss chard and five harvests of basil. Total basil yield from the five harvests was 1.6-5 times greater than the total yield from the unamended control, while total Swiss chard yield from the four harvests was 2-5 times greater relative to the respective unamended control. The addition of wool-waste to the growth medium increased Swiss chard and basil tissue N, and NO{sub 3}-N and NH{sub 4}-N in growth medium relative to the unamended control. Scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) microanalysis of wool fibers sampled at the end of the experiments indicated various levels of decomposition, with some fibers retaining their original surface structure. Furthermore, most of the wool fibers' surfaces contained significant concentrations of S and much less N, P, or K. SEM/EDX revealed that some plant roots grow directly on wool-waste fibers suggesting either (1) root directional growth towards sites with greater nutrient concentration and/or (2) a possible role for roots or root exudates in wool decomposition. Results from this study suggest that uncomposted wool wastes can be used as soil amendment, growth medium constituent, and nutrient source for container-grown plants.

  20. A Method to Teach Age-Specific Demography with Field Grown Rapid Cycling "Brassica rapa" (Wisconsin Fast Plants)

    ERIC Educational Resources Information Center

    Kelly, Martin G.; Terrana, Sebastian

    2004-01-01

    In this paper, we demonstrate that rapid cycling "Brassica rapa" (Wisconsin Fast Plants) can be used in inquiry-based, student ecological fieldwork. We are the first to describe age-specific survival for field-grown Fast Plants and identify life history traits associated with individual survival. This experiment can be adapted by educators as a…

  1. Effect of crop development on biogenic emissions from plant populations grown in closed plant growth chambers

    NASA Technical Reports Server (NTRS)

    Batten, J. H.; Stutte, G. W.; Wheeler, R. M.

    1995-01-01

    The Biomass Production Chamber at John F. Kennedy Space Center is a closed plant growth chamber facility that can be used to monitor the level of biogenic emissions from large populations of plants throughout their entire growth cycle. The head space atmosphere of a 26-day-old lettuce (Lactuca sativa cv. Waldmann's Green) stand was repeatedly sampled and emissions identified and quantified using GC-mass spectrometry. Concentrations of dimethyl sulphide, carbon disulphide, alpha-pinene, furan and 2-methylfuran were not significantly different throughout the day; whereas, isoprene showed significant differences in concentration between samples collected in light and dark periods. Volatile organic compounds from the atmosphere of wheat (Triticum aestivum cv. Yecora Rojo) were analysed and quantified from planting to maturity. Volatile plant-derived compounds included 1-butanol, 2-ethyl-1-hexanol, nonanal, benzaldehyde, tetramethylurea, tetramethylthiourea, 2-methylfuran and 3-methylfuran. Concentrations of volatiles were determined during seedling establishment, vegetative growth, anthesis, grain fill and senescence and found to vary depending on the developmental stage. Atmospheric concentrations of benzaldehyde and nonanal were highest during anthesis, 2-methylfuran and 3-methylfuran concentrations were greatest during grain fill, and the concentration of the tetramethylurea peaked during senescence.

  2. Thermodynamic and structural properties of tuber starches from transgenic potato plants grown in vitro and in vivo.

    PubMed

    Wasserman, Luybov A; Sergeev, Andrey I; Vasil'ev, Viktor G; Plashchina, Irina G; Aksenova, Nina P; Konstantinova, Tatyana N; Golyanovskaya, Svetlana A; Sergeeva, Lidiya I; Romanov, Georgy A

    2015-07-10

    Potato plants harboring Phytochrome B (PHYB) gene from Arabidopsis thaliana or rol genes from Agrobacterium rhizogenes were used to study the effect of transgene expression on structure and properties of starch in tubers. Thermodynamic characteristics of starch (melting temperature, enthalpy of melting, thickness of crystalline lamellae) were shown to be variable depending on the transgene expression and plant culturing mode: in vitro or in soil. The expression of rolB or rolC genes in in vitro cultured plants evoked opposite effects on starch melting temperature and crystalline lamellae thickness. AtPHYB or rolB expression in the soil-grown potato led to the formation of more defective or more ordered starch structures, respectively, in comparison with starches of the same lines grown in vitro. On the whole, our study revealed genotype-dependent differences between starches extracted from tubers of in vitro or in vivo grown plants.

  3. Occurrence of Transgenic Feral Alfalfa (Medicago sativa subsp. sativa L.) in Alfalfa Seed Production Areas in the United States

    PubMed Central

    Greene, Stephanie L.; Kesoju, Sandya R.; Martin, Ruth C.; Kramer, Matthew

    2015-01-01

    The potential environmental risks of transgene exposure are not clear for alfalfa (Medicago sativa subsp. sativa), a perennial crop that is cross-pollinated by insects. We gathered data on feral alfalfa in major alfalfa seed-production areas in the western United States to (1) evaluate evidence that feral transgenic plants spread transgenes and (2) determine environmental and agricultural production factors influencing the location of feral alfalfa, especially transgenic plants. Road verges in Fresno, California; Canyon, Idaho; and Walla Walla, Washington were surveyed in 2011 and 2012 for feral plants, and samples were tested for the CP4 EPSPS protein that conveys resistance to glyphosate. Of 4580 sites surveyed, feral plants were observed at 404 sites. Twenty-seven percent of these sites had transgenic plants. The frequency of sites having transgenic feral plants varied among our study areas. Transgenic plants were found in 32.7%, 21.4.7% and 8.3% of feral plant sites in Fresno, Canyon and Walla Walla, respectively. Spatial analysis suggested that feral populations started independently and tended to cluster in seed and hay production areas, places where seed tended to drop. Significant but low spatial auto correlation suggested that in some instances, plants colonized nearby locations. Neighboring feral plants were frequently within pollinator foraging range; however, further research is needed to confirm transgene flow. Locations of feral plant clusters were not well predicted by environmental and production variables. However, the likelihood of seed spillage during production and transport had predictive value in explaining the occurrence of transgenic feral populations. Our study confirms that genetically engineered alfalfa has dispersed into the environment, and suggests that minimizing seed spillage and eradicating feral alfalfa along road sides would be effective strategies to minimize transgene dispersal. PMID:26699337

  4. Occurrence of Transgenic Feral Alfalfa (Medicago sativa subsp. sativa L.) in Alfalfa Seed Production Areas in the United States.

    PubMed

    Greene, Stephanie L; Kesoju, Sandya R; Martin, Ruth C; Kramer, Matthew

    2015-01-01

    The potential environmental risks of transgene exposure are not clear for alfalfa (Medicago sativa subsp. sativa), a perennial crop that is cross-pollinated by insects. We gathered data on feral alfalfa in major alfalfa seed-production areas in the western United States to (1) evaluate evidence that feral transgenic plants spread transgenes and (2) determine environmental and agricultural production factors influencing the location of feral alfalfa, especially transgenic plants. Road verges in Fresno, California; Canyon, Idaho; and Walla Walla, Washington were surveyed in 2011 and 2012 for feral plants, and samples were tested for the CP4 EPSPS protein that conveys resistance to glyphosate. Of 4580 sites surveyed, feral plants were observed at 404 sites. Twenty-seven percent of these sites had transgenic plants. The frequency of sites having transgenic feral plants varied among our study areas. Transgenic plants were found in 32.7%, 21.4.7% and 8.3% of feral plant sites in Fresno, Canyon and Walla Walla, respectively. Spatial analysis suggested that feral populations started independently and tended to cluster in seed and hay production areas, places where seed tended to drop. Significant but low spatial auto correlation suggested that in some instances, plants colonized nearby locations. Neighboring feral plants were frequently within pollinator foraging range; however, further research is needed to confirm transgene flow. Locations of feral plant clusters were not well predicted by environmental and production variables. However, the likelihood of seed spillage during production and transport had predictive value in explaining the occurrence of transgenic feral populations. Our study confirms that genetically engineered alfalfa has dispersed into the environment, and suggests that minimizing seed spillage and eradicating feral alfalfa along road sides would be effective strategies to minimize transgene dispersal.

  5. Perfluoroalkyl acid distribution in various plant compartments of edible crops grown in biosolids-amended soils.

    PubMed

    Blaine, Andrea C; Rich, Courtney D; Sedlacko, Erin M; Hundal, Lakhwinder S; Kumar, Kuldip; Lau, Christopher; Mills, Marc A; Harris, Kimberly M; Higgins, Christopher P

    2014-07-15

    Crop uptake of perfluoroalkyl acids (PFAAs) from biosolids-amended soil has been identified as a potential pathway for PFAA entry into the terrestrial food chain. This study compared the uptake of PFAAs in greenhouse-grown radish (Raphanus sativus), celery (Apium graveolens var. dulce), tomato (Lycopersicon lycopersicum), and sugar snap pea (Pisum sativum var. macrocarpon) from an industrially impacted biosolids-amended soil, a municipal biosolids-amended soil, and a control soil. Individual concentrations of PFAAs, on a dry weight basis, in mature, edible portions of crops grown in soil amended with PFAA industrially impacted biosolids were highest for perfluorooctanoate (PFOA; 67 ng/g) in radish root, perfluorobutanoate (PFBA; 232 ng/g) in celery shoot, and PFBA (150 ng/g) in pea fruit. Comparatively, PFAA concentrations in edible compartments of crops grown in the municipal biosolids-amended soil and in the control soil were less than 25 ng/g. Bioaccumulation factors (BAFs) were calculated for the root, shoot, and fruit compartments (as applicable) of all crops grown in the industrially impacted soil. BAFs were highest for PFBA in the shoots of all crops, as well as in the fruit compartment of pea. Root-soil concentration factors (RCFs) for tomato and pea were independent of PFAA chain length, while radish and celery RCFs showed a slight decrease with increasing chain length. Shoot-soil concentration factors (SCFs) for all crops showed a decrease with increasing chain length (0.11 to 0.36 log decrease per CF2 group). The biggest decrease (0.54-0.58 log decrease per CF2 group) was seen in fruit-soil concentration factors (FCFs). Crop anatomy and PFAA properties were utilized to explain data trends. In general, fruit crops were found to accumulate fewer long-chain PFAAs than shoot or root crops presumably due to an increasing number of biological barriers as the contaminant is transported throughout the plant (roots to shoots to fruits). These data were

  6. Chalkbrood Transmission in the Alfalfa Leafcutting Bee: The Impact of Disinfecting Bee Cocoons in Loose Cell Management Systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A good understanding of pathogen transmission in a host population should illuminate methods for disease prevention and control. A case in point for this is the alfalfa leafcutting bee (Megachile rotundata), a solitary bee which is used extensively for pollination of alfalfa grown for seed. Propaga...

  7. Changes of mesophyll and the rubisco activity in pea plants grown in clinostat

    NASA Astrophysics Data System (ADS)

    Adamchuk, N. I.

    In earlier research, it was found that microgravity causes alteration of mesophyll cell parameters and dislication at the ultrastructural level (Kordyum et al., 1989, Nedukha et al., 1991, Kordyum, 1997, Adamchuk et al., 2002). Also, destruction of the fine structure of chloroplasts was reported by Abilov et al. (1986), Aliev et al. (1987), Kordyum et al. (1989), and Adamchuk et al. (1999). In addition, Abilov et al. (1986), Aliev et al. (1987), Brown et al. (1993) have discovered the decrease in starch volume. The objective of this work was to compare quantitative ultrastructural parameters of mesophyll cells (including properties of their chloroplasts) and the level of Rubisco activity detected in clinorotated and control plants of pea (Pisum sativum L.). Plants were grown for 12 days in the nutritional medium of Hogland on a clinostat (with 2 rev. min-1 speed of rotation) at a temperature of 23-25°C and illumination 230 μ mol per m-2s-1. The comparison of transversal cross-sections of leaves has revealed a significant increase of mesophyll cell volume and intercellular space under experimental conditions. This expansion of mesophyll cells has correlated with an increase of the number of chloroplasts. Essential ultrastructural changes have affected the total volume of thylakoids. Also, the value of the photosynthetic membranes development in the clinorotated plants was higher 17.11 ± 1.94 μ m3 then in control -- 12.65 ± 1.83 μ m3 due to extension of destacking thylakoids. Increase of the volume density of plastoglobuli in the clinorotated plants on the 1.63-fold suggested the effect of either greater accumulation of lipid or acceleration of chloroplasts senescence. Under influence of clinorotation, the partial volume of starch inclusions significantly decreased in the spongy mesophyll chloroplasts -- 10.46 ± 1.80 % to compare with control -- 31.34 ± 2.37 %. However, the clinorotation of plants resulted in an increase of the Rubisco activity. Intensities

  8. Plant age and genotype affect the bacterial community composition in the tuber rhizosphere of field-grown sweet potato plants.

    PubMed

    Marques, Joana M; da Silva, Thais F; Vollu, Renata E; Blank, Arie F; Ding, Guo-Chun; Seldin, Lucy; Smalla, Kornelia

    2014-05-01

    The hypothesis that sweet potato genotypes containing different starch yields in their tuberous roots can affect the bacterial communities present in the rhizosphere (soil adhering to tubers) was tested in this study. Tuberous roots of field-grown sweet potato of genotypes IPB-149 (commercial genotype), IPB-052, and IPB-137 were sampled three and six months after planting and analyzed by denaturing gradient gel electrophoresis (DGGE) and pyrosequencing analysis of 16S rRNA genes PCR-amplified from total community DNA. The statistical analysis of the DGGE fingerprints showed that both plant age and genotypes influenced the bacterial community structure in the tuber rhizosphere. Pyrosequencing analysis showed that the IPB-149 and IPB-052 (both with high starch content) displayed similar bacterial composition in the tuber rhizosphere, while IPB-137 with the lowest starch content was distinct. In comparison with bulk soil, higher 16S rRNA gene copy numbers (qPCR) and numerous genera with significantly increased abundance in the tuber rhizosphere of IPB-137 (Sphingobium, Pseudomonas, Acinetobacter, Stenotrophomonas, Chryseobacterium) indicated a stronger rhizosphere effect. The genus Bacillus was strongly enriched in the tuber rhizosphere samples of all sweet potato genotypes studied, while other genera showed a plant genotype-dependent abundance. This is the first report on the molecular identification of bacteria being associated with the tuber rhizosphere of different sweet potato genotypes.

  9. Woody plant diversity and structure of shade-grown-coffee plantations in northern Chiapas, Mexico.

    PubMed

    Soto-Pinto, L; Romero-Alvarado, Y; Caballero-Nieto, J; Segura Warnholtz, G

    2001-01-01

    Shade-grown coffee is an agricultural system that contains some forest-like characteristics. However, structure and diversity are poorly known in shade coffee systems. In 61 coffee-growers' plots of Chiapas, Mexico, structural variables of shade vegetation and coffee yields were measured, recording species and their use. Coffee stands had five vegetation strata. Seventy seven woody species mostly used as wood were found (mean density 371.4 trees per hectare). Ninety percent were native species (40% of the local flora), the remaining were introduced species, mainly fruit trees/shrubs. Diametric distribution resembles that of a secondary forest. Principal Coordinates Analysis grouped plots in four classes by the presence of Inga, however the majority of plots are diverse. There was no difference in equitability among groups or coffee yields. Coffee yield was 835 g clean coffee per shrub, or ca. 1,668 kg ha-1. There is a significant role of shade-grown coffee as diversity refuge for woody plants and presumably associated fauna as well as an opportunity for shade-coffee growers to participate in the new biodiversity-friendly-coffee market.

  10. Toxicity assessment of cerium oxide nanoparticles in cilantro (Coriandrum sativum L.) plants grown in organic soil.

    PubMed

    Morales, Maria Isabel; Rico, Cyren M; Hernandez-Viezcas, Jose Angel; Nunez, Jose E; Barrios, Ana Cecilia; Tafoya, Alejandro; Flores-Marges, Juan Pedro; Peralta-Videa, Jose R; Gardea-Torresdey, Jorge L

    2013-07-03

    Studies have shown that CeO₂ nanoparticles (NPs) can be accumulated in plants without modification, which could pose a threat for human health. In this research, cilantro (Coriandrum sativum L.) plants were germinated and grown for 30 days in soil amended with 0 to 500 mg kg⁻¹ CeO₂ NPs and analyzed by spectroscopic techniques and biochemical assays. At 125 mg kg⁻¹, plants produced longer roots (p ≤ 0.05), and at 500 mg kg⁻¹, there was higher Ce accumulation in tissues (p ≤ 0.05). At 125 mg, catalase activity significantly increased in shoots and ascorbate peroxidase in roots (p ≤ 0.05). The FTIR analyses revealed that at 125 mg kg⁻¹ the CeO₂ NPs changed the chemical environment of carbohydrates in cilantro shoots, for which changes in the area of the stretching frequencies were observed. This suggests that the CeO₂ NPs could change the nutritional properties of cilantro.

  11. Mechanism of physiological effects of titanium leaf sprays on plants grown on soil.

    PubMed

    Kuzel, Stanislav; Hruby, Martin; Cígler, Petr; Tlustos, Pavel; Van, Phu Nguyen

    2003-02-01

    Titanium (Ti) has significant biological effects on plants, being beneficial at low and toxic at higher concentrations. From results of our hydroponical experiment with oats, we have recently proposed that the effect called hormesis is the mechanism of Ti action in plants. Here, we present the experiment with oats (Avena sativa L. cv. Zlat'ák) grown on soil where Ti was applied using leaf sprays. Two different soils, three different concentrations of Ti(IV) citrate spray solution (0, 20, and 50 mg Ti/kg), and three different Mg concentrations in each soil were tested. Some physiological parameters (dry and raw weights, top heights, chlorophyll content) and element contents (Mg, Fe, Zn, Mn) were determined. Ti showed considerable effects on all physiological parameters and the element's contents were determined. Differences between the two different soil types used was only in the strength of the effect of Ti; the trends remained unchanged. Generally, the effect of Ti is considerably weaker if Ti is applied on leaves than if being added to the nutrient solution. Thus, we confirm here that the action of Ti on plants could be explained by the hormesis effect.

  12. Preference of the green peach aphid, Myzus persicae, for plants grown in sewage sludges

    SciTech Connect

    Culliney, T.W.; Pimentel, D.

    1987-08-01

    Since passage of the Clean Water Act in the 1970s, disposal of the millions of tonnes of sewage sludge generated annually has become a major concern of municipalities throughout the United States. With the range of other disposal options having narrowed in recent years, application of sludge to land is increasingly viewed as a practical and economical means to recycle this waste material. However, sludges from large cities with industries may be contaminated with various toxic chemicals, including polychlorinated biphenyls (PCBs), other organic chemicals, such as pesticides, and heavy metals. Sludge application to land thus has the potential adversely to affect biota and the functioning of terrestrial ecosystems. The authors previously demonstrated marked reductions in fecundity and survival of green peach aphids, Myzus persicae, on collard plants, Brassica oleracea var. sabellica, growing in soil treated with chemically contaminated sludge as compared to aphids on plants growing either in soil treated with uncontaminated sludge of soil conventionally fertilized. Reduced plant growth and increased restlessness in aphids in the contaminated sludge treatment were also observed. The purpose of the present study was to examine more closely the influence of sludge contaminants on aphid settling behavior as indicated by differential preference of M. persicae for leaves of its collard host grown under different soil conditions.

  13. First systematic evaluation of the potency of Cannabis sativa plants grown in Albania.

    PubMed

    Bruci, Zana; Papoutsis, Ioannis; Athanaselis, Sotirios; Nikolaou, Panagiota; Pazari, Ermira; Spiliopoulou, Chara; Vyshka, Gentian

    2012-10-10

    Cannabis products (marijuana, hashish, cannabis oil) are the most frequently abused illegal substances worldwide. Delta-9-tetrahydrocannabinol (THC) is the main psychoactive component of Cannabis sativa plant, whereas cannabidiol (CBD) and cannabinol (CBN) are other major but no psychoactive constituents. Many studies have already been carried out on these compounds and chemical research was encouraged due to the legal implications concerning the misuse of marijuana. The aim of this study was to determine THC, CBD and CBN in a significant number of cannabis samples of Albanian origin, where cannabis is the most frequently used drug of abuse, in order to evaluate and classify them according to their cannabinoid composition. A GC-MS method was used, in order to assay cannabinoid content of hemp samples harvested at different maturation degree levels during the summer months and grown in different areas of Albania. This method can also be used for the determination of plant phenotype, the evaluation of psychoactive potency and the control of material quality. The highest cannabinoid concentrations were found in the flowers of cannabis. The THC concentrations in different locations of Albania ranged from 1.07 to 12.13%. The influence of environmental conditions on cannabinoid content is discussed. The cannabinoid content of cannabis plants were used for their profiling, and it was used for their classification, according to their geographical origin. The determined concentrations justify the fact that Albania is an area where cannabis is extensively cultivated for illegal purposes.

  14. Screening the antiangiogenic activity of medicinal plants grown and sold in Jordan.

    PubMed

    Zihlif, Malek; Afifi, Fatma; Muhtaseb, Ruba; Al-Khatib, Sondos; Abaza, Ismail; Naffa, Randa

    2012-02-01

    Angiogenesis is essential for the growth, invasion, and metastasis of most solid tumors and has become a valuable pharmacological target for cancer prevention and treatment. This study was performed to assess the antiangiogenic activity of 31 medicinal plants grown and sold in Jordan. The antiangiogenic activity was assessed using the rat aortic ring assay. Out of 31 extracts, 15 extracts showed more than 50 % inhibition of the blood vessels outgrowth from the primary tissue explants (p = 0.000). Three of these 15 extracts showed a potential cytotoxic effect on normal fibroblast cells. Four extracts shared antiangiogenic and antiproliferative activity towards MCF7 breast cancer cell lines. Eight extracts demonstrated selective antiangiogenic activity. This is the first report demonstrating the potential antiangiogenic activity of Artemisia judaica, Aloysia citriodora, Salvia egyptiaca, and Calendula arvensis. Some extracts with antiangiogenic activity exhibited selectivity against the endothelial cells proliferation, demonstrating a direct inhibitory activity against the key step in tumor angiogenesis.

  15. Effects of ammonium on elemental nutrition of red spruce and indicator plants grown in acid soil

    SciTech Connect

    Hoelldampf, B.; Barker, A.V. )

    1993-01-01

    Decline of high elevation red spruce forests in the northeastern United States has been related to acid rain, particularly with respect to the deposition of nitrogenous materials. Ca and Mg deficiencies may be induced by input of air-borne nitrogenous nutrients into the forest ecosystem. This research investigated the effects of N nutrition on mineral nutrition of red spruce and radish, as an indicator plant, grown in acid forest soil. Red spruce and radishes in the greenhouse were treated with complete nutrient solutions with 15 mM N supplied as 0, 3.75, 7.5, 11.25, or 15 mM NH[sub 4][sup +] with the remainder being supplied as NO[sub 3][sup [minus

  16. Accumulation of mercury in selected plant species grown in soils contaminated with different mercury compounds

    SciTech Connect

    Su, Yi; Han, Fengxiang; Shiyab, Safwan; Chen, Jian; Monts, David L.

    2007-07-01

    , such as Indian mustard (Brassica juncea), a well-studied metal accumulator, exhibited severe chlorosis symptoms during some experiments. Among all the plant species studied, Chinese brake fern (Pteris vittata) accumulated significant amount of mercury in both roots and shoots and hence may be considered as a potential candidate for mercury phyto-extraction. During one experiment, Chinese brake ferns accumulated 540 mg/kg and 1469 mg/kg in shoots after 18 days of growing in soils treated with 500 parts-per-million (ppm) and 1000 ppm HgCl{sub 2} powder, respectively; no visual stress symptoms were observed. We also studied mercury phyto-remediation using aged soils that contained HgS, HgCl{sub 2}, or Hg(NO{sub 3}){sub 2}. We have found that up to hundreds of ppm mercury can be accumulated in the roots of Indian mustard plants grown with soil contaminated by mercury sulfide; HgS is assumed to be the most stable and also the predominant mercury form in flood plain soils. We have also started to investigate different mercury uptake mechanisms, such as root uptake of soil contaminant and foliar mercury accumulation from ambient air. We have observed mercury translocation from roots to shoot for Chinese fern and two Indian mustard varieties. (authors)

  17. Analysis of genetic relationships among Rosa damascena plants grown in Turkey by using AFLP and microsatellite markers.

    PubMed

    Baydar, Nilgün Göktürk; Baydar, Hasan; Debener, Thomas

    2004-08-05

    Rosa damascena Mill. is the most important rose species for rose oil production. The main rose oil producers in the world are Turkey and Bulgaria and they obtain the rose oil almost exclusively from R. damascena. In spite of coming from the same original populations, R. damascena plants grown in Turkey show some morphological differences. In this study, it was aimed to investigate the genetic relationships among R. damascena plants grown in Turkey by using microsatellite and AFLP markers. Twenty three AFLP and nine microsatellite primer pairs were used for this aim. No polymorphism could be detected among the plants, as the marker patterns obtained from different plants are identical. The conclusion from these data is that all R. damascena plants under study are derived from the same original genotype by vegetative propagation. Furthermore, the observed morphological differences originate from point mutations not detectable by molecular markers. Therefore, they are equivalent to sport mutations frequently observed in cut and garden rose varieties.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alfalfa (Medicago sativa L.) plants were transformed with two constructs: (1) a truncated phosphoenolpyruvate carboxylase promoter isolated from alfalfa nodules (PEPC-4) fused to GUS; and (2) PEPC-4 fused with sucrose synthase (SUS) isolated from alfalfa nodules. Histochemical staining for GUS in st...

  19. The effects of Pantoea sp.Y4-4 on alfalfa in the remediation of heavy-metal-contaminated soil and auxiliary impacts of plant residues on the remediation of saline alkali soils.

    PubMed

    Li, Shuhuan; Wang, Jie; Gao, Nanxiong; Liu, Lizhu; Chen, Yahua

    2016-11-30

    The plant growth-promoting rhizobacteria (PGPR) Y4-4 was isolated from plant rhizosphere soil and identified as Pantoea sp. by 16S rRNA sequence analysis. The effects of strain Y4-4 on alfalfa grew in heavy metals contaminated soil was investigated using a pot experiment. In Cu rich environment, the dry weight from shoot and total of plant inoculated with strain Y4-4 increased by 22.6% and 21%, and Cu accumulation increased by 15%. In Pb-Zn rich environment, the dry weight from shoot and total of plant inoculated with strain Y4-4 increased by 23.4% and 22%, and Zn accumulation increased by 30.3%. In addition, the salt tolerance and biomass of wheat seedling could be improved by applying strain Y4-4 mixed with plant residue as a result of Cu-rich plant residues provide copper nutrition wheat. This study offers an efficient PGPR with strong salt tolerance and a safe strategy for the post-treatment of plant residue.

  20. Effects of different carbohydrate sources on fructan metabolism in plants of Chrysolaena obovata grown in vitro

    PubMed Central

    Trevisan, Flavio; Oliveira, Vanessa F.; Carvalho, Maria A. M.; Gaspar, Marília

    2015-01-01

    Chrysolaena obovata (Less.) Dematt., previously named Vernonia herbacea, is an Asteraceae native to the Cerrado which accumulates about 80% of the rhizophore dry mass as inulin-type fructans. Considering its high inulin production and the wide application of fructans, a protocol for C. obovata in vitro culture was recently established. Carbohydrates are essential for in vitro growth and development of plants and can also act as signaling molecules involved in cellular adjustments and metabolic regulation. This work aimed to evaluate the effect of different sources of carbohydrate on fructan metabolism in plants grown in vitro. For this purpose, C. obovata plants cultivated in vitro were submitted to carbon deprivation and transferred to MS medium supplemented with sucrose, glucose or fructose. Following, their fructan composition and activity and expression of genes encoding enzymes for fructan synthesis (1-SST and 1-FFT) and degradation (1-FEH) were evaluated. For qRT-PCR analysis partial cDNA sequences corresponding to two different C. obovata genes, 1-SST and 1-FFT, were isolated. As expected, C. obovata sequences showed highest sequence identity to other Asteraceae 1-SST and 1-FFT, than to Poaceae related proteins. A carbon deficit treatment stimulated the transcription of the gene 1-FEH and inhibited 1-SST and 1-FFT and carbohydrate supplementation promoted reversal of the expression profile of these genes. With the exception of 1-FFT, a positive correlation between enzyme activity and gene expression was observed. The overall results indicate that sucrose, fructose and glucose act similarly on fructan metabolism and that 1-FEH and 1-SST are transcriptionally regulated by sugar in this species. Cultivation of plants in increasing sucrose concentrations stimulated synthesis and inhibited fructan mobilization, and induced a distinct pattern of enzyme activity for 1-SST and 1-FFT, indicating the existence of a mechanism for differential regulation between them

  1. Effects of different carbohydrate sources on fructan metabolism in plants of Chrysolaena obovata grown in vitro.

    PubMed

    Trevisan, Flavio; Oliveira, Vanessa F; Carvalho, Maria A M; Gaspar, Marília

    2015-01-01

    Chrysolaena obovata (Less.) Dematt., previously named Vernonia herbacea, is an Asteraceae native to the Cerrado which accumulates about 80% of the rhizophore dry mass as inulin-type fructans. Considering its high inulin production and the wide application of fructans, a protocol for C. obovata in vitro culture was recently established. Carbohydrates are essential for in vitro growth and development of plants and can also act as signaling molecules involved in cellular adjustments and metabolic regulation. This work aimed to evaluate the effect of different sources of carbohydrate on fructan metabolism in plants grown in vitro. For this purpose, C. obovata plants cultivated in vitro were submitted to carbon deprivation and transferred to MS medium supplemented with sucrose, glucose or fructose. Following, their fructan composition and activity and expression of genes encoding enzymes for fructan synthesis (1-SST and 1-FFT) and degradation (1-FEH) were evaluated. For qRT-PCR analysis partial cDNA sequences corresponding to two different C. obovata genes, 1-SST and 1-FFT, were isolated. As expected, C. obovata sequences showed highest sequence identity to other Asteraceae 1-SST and 1-FFT, than to Poaceae related proteins. A carbon deficit treatment stimulated the transcription of the gene 1-FEH and inhibited 1-SST and 1-FFT and carbohydrate supplementation promoted reversal of the expression profile of these genes. With the exception of 1-FFT, a positive correlation between enzyme activity and gene expression was observed. The overall results indicate that sucrose, fructose and glucose act similarly on fructan metabolism and that 1-FEH and 1-SST are transcriptionally regulated by sugar in this species. Cultivation of plants in increasing sucrose concentrations stimulated synthesis and inhibited fructan mobilization, and induced a distinct pattern of enzyme activity for 1-SST and 1-FFT, indicating the existence of a mechanism for differential regulation between them.

  2. Nitrogen Fixation, Nodule Development, and Vegetative Regrowth of Alfalfa (Medicago sativa L.) following Harvest 1

    PubMed Central

    Vance, Carroll P.; Heichel, Gary H.; Barnes, Donald K.; Bryan, Jeff W.; Johnson, Lois E.

    1979-01-01

    Nitrogenase-dependent acetylene reduction, nodule function, and nodule regrowth were studied during vegetative regrowth of harvested (detopped) alfalfa (Medicago sativa L.) seedlings grown in the glasshouse. Compared with controls, harvesting caused an 88% decline in acetylene reduction capacity of detached root systems within 24 hours. Acetylene reduction in harvested plants remained low for 13 days, then increased to a level comparable to the controls by day 18. Protease activity increased in nodules from harvested plants, reached a maximum at day 7 after harvest, and then declined to a level almost equal to the control by day 22 after harvest. Soluble protein and leghemoglobin decreased in nodules from harvested plants in an inverse relationship to protease activity. Nitrate reductase activity of nodules from harvested plants increased significantly within 24 hours and was inversely associated with acetylene reduction. The difference in nitrate reductase between nodules from harvested plants and control plants became less evident as shoot regrowth occurred and as acetylene reduction increased in the harvested plants. No massive loss of nodules occurred after harvest as evidenced by little net change in nodule fresh weight. There was, however, a rapid localized senescence which occurred in nodules of harvested plants. Histology of nodules from harvested plants showed that they degenerated at the proximal end after harvest. Starch in the nodule was depleted by 10 days after harvest. The meristem and vascular bundles of nodules from harvested plants remained intact. The senescent nodules began to regrow and fix nitrogen after shoot growth resumed. Images PMID:16660893

  3. Economics of growth regulator treatment of alfalfa seed for interseeding into silage corn

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous studies have focused on interseeding of alfalfa into corn for use as a temporary cover crop rather than as a means of jump-starting alfalfa production after corn. In ongoing field studies, we are evaluating whether plant growth regulators (PGR) may be used to aid the establishment of inters...

  4. Mapping fall dormancy and winter injury in tetraploid alfalfa (Medicago sativa L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alfalfa is a widely planted perennial forage crop. Dormancy in autumn (fall dormancy) is generally negatively correlated with winter injury in alfalfa. To understand the genetic basis of the two traits, we identified quantitative trait loci (QTL) controlling autumn growth and winter injury using a...

  5. Relationship of red and photographic infrared spectral radiances to alfalfa biomass, forage water content, percentage canopy cover, and severity of drought stress

    NASA Technical Reports Server (NTRS)

    Tucker, C. J.; Elgin, J. H., Jr.; Mcmurtrey, J. E., III

    1979-01-01

    Red and photographic infrared spectral data were collected using a handheld radiometer for two cuttings of alfalfa. Significant linear and non-linear correlation coefficients were found between the spectral variables and plant height, biomass, forage water content, and estimated canopy cover for the earlier alfalfa cutting. The alfalfa of later cutting experienced a period of severe drought stress which limited growth. The spectral variables were found to be highly correlated with the estimated drought scores for this alfalfa cutting.

  6. Plant density-dependent variations in bioactive markers and root yield in Australian-grown Salvia miltiorrhiza Bunge.

    PubMed

    Li, Chun Guang; Sheng, Shu Jun; Pang, Edwin C K; May, Brian; Xue, Charlie Chang Li

    2011-04-01

    The plant density-dependent variations in the root yield and content, and the yield of biomarkers in Australian grown Salvia miltiorrhiza Bunge, a commonly used Chinese medicinal herb for the treatment of cardiovascular diseases, were investigated in a field trial involving six different plant densities. The key biomarker compounds cryptotanshinone, tanshinone I, tanshinone IIA, and salvianolic acid B were quantified by a validated RP-HPLC method, and the root yields were determined per plant pair or unit area. There were significant variations (p<0.05) in the root yields and contents and the yields of the biomarkers between the different plant densities. Positive linear correlations were observed between the contents of the three tanshinones, whereas negative linear correlations were revealed between the contents of the tanshinones and salvianolic acid B. The highest root yield per plant pair was achieved when the plants were grown at 45×30 cm or 45×40 cm, whereas the highest root production par unit area was obtained for a plant density of 30×30 cm. The highest contents of the three tanshinones and the most abundant production of these tanshinones per unit area were achieved when the plants were grown at 30×30 cm. However, the highest content of salvianolic acid B was found for a density of 45×40 cm, while its highest yield per unit area was obtained for densities of 30×40 cm or 45×30 cm. The findings suggest that the plant density distinctly affects the root yield and content and the yield of tanshinones and salvianolic acid B in Australian grown S. miltiorrhiza, which may be used as a guide for developing optimal agricultural procedures for cultivating this herb.

  7. Impact of alfalfa on soil and water quality

    SciTech Connect

    Sharma, P.; Moncrief, J.; Gupta, S.

    1997-10-30

    Dominance of row crop agriculture in rolling landscapes of western and Southwestern Minnesota is identified as a primary, non-point source of sediments and associated pollutants reaching the Minnesota River. Currently as a biomass energy project, alfalfa is being promoted in western Minnesota to harvest the leaves for animal feed and stems to generate electricity. As a perennial, leguminous crop grown with minimum inputs, introduction of alfalfa in row cropped lands has potential to improve both in-situ soil productivity and downstream water quality. A field study was initiated in 1996 to compare the volume of runoff and pollutants coming from alfalfa an com-soybean fields in western Minnesota. Two pair of alfalfa and corn-soybean watersheds were instrumented at Morris in the Fall of 1996 to measure rainfall, runoff, and sample water for sediment load, phosphorus, nitrogen, biochemical oxygen demand, and chemical oxygen demand. Simulated rainfall-runoff experiments were conducted on an existing crop rotation - input management study plots at Lamberton to evaluate soil quality effects of the inclusion of alfalfa in a corn-soybean rotation under manure and fertilization management schemes. Alfalfa soil water use as a function of frequency of harvest was also monitored at Morris to evaluate the effect of cutting schedule on soil water use. During the growing season of 1997, alfalfa under a two-cut management scheme used about 25-mm (an inch) more soil water than under a three-cut schedule. The mean differences between the treatments were not significant. The conclusions drawn in this report come from analysis of data collected during one winter-summer hydrologic and crop management cycle. Continued observations through a period of at least 3-5 years is recommended to improve the instrumentation robustness and discern the variability due to climate, soil, and crop management factors.

  8. Oxidative burst in alfalfa-Sinorhizobium meliloti symbiotic interaction.

    PubMed

    Santos, R; Hérouart, D; Sigaud, S; Touati, D; Puppo, A

    2001-01-01

    Reactive oxygen species are produced as an early event in plant defense response against avirulent pathogens. We show here that alfalfa responds to infection with Sinorhizobium meliloti by production of superoxide and hydrogen peroxide. This similarity in the early response to infection by pathogenic and symbiotic bacteria addresses the question of which mechanism rhizobia use to counteract the plant defense response.

  9. EDTA reduces the physiological damage of lead on cardoon plants grown hydroponically

    NASA Astrophysics Data System (ADS)

    Hernandez-Allica, J.; Barrutia, O.; Becerril, J. M.; Garbisu, C.

    2003-05-01

    Cardoon seedlings (Cynara cardunculus L.) were grown hydroponically in nutrient solution and exposed to lead (Pb^{2+}: ImM) in the presence of a range of different EDTA concentrations (EDTANa2: 0, 0.5, 1 or 2mM). Analyses were performed to establish whether the coordination of Pb^{2+} transport by EDTA enhances the mobility of this metal within the plant and to determine the toxic effects of these treatments during a phytoextraction process. Net photosynthesis, transpiration rate and stomatal conductance decreased dramatically in plants treated with Pb^{2+} or Pb-EDTA at doses below 1 mM. ln these treatments, most of the Pb^{2+} accumulated in the roots, alld only a very low amount of it was translocated to the shoots. Increasing the EDTA doses up to Pb^{2+} equimolarity, increased the Pb^{2+} shoot content more than 10-fold without any physiological evidence of toxicity. The treatment with higher doses of EDTA (Pb^{2+} 1 mM + EDTA 2 mM) did not show toxicity symptoms, but the Pb^{2+} concentration in the aboveground tissues decreased when compared with the equimolar treatment. The interaction with the absorption of some essential cations such as Ca^{2+} and phytotoxicity on chelated-assisted phytoextraction is discussed.

  10. Growth and chlorophyll production in plant callus tissues grown in vitro.

    PubMed

    Vasil, I K; Hildebrandt, A C

    1966-03-01

    Growth, nutrition and chlorophyll development were studied in chlorophyllous callus tissues isolated from the following edible angiospermous plants: carrot root, crown gall of tomato, endive embryo, leaf petiole and stem of lettuce, leaf petiole of parsley, pea stem and rose stem. Growth patterns of these tissues in vitro were sigmoid. Synthetic media produced less growth, in terms of fresh weight increase, than media containing coconut milk, a highly complex and little understood natural substance. MURASHIGE and SKOOG'S synthetic medium proved useful for satisfactory growth and chlorophyll production in a number of tissues. Its usefulness was further increased by additional amounts of copper sulphate, potassium nitrate and monobasic ammonium phosphate. Increased levels of iron and magnesium inhibited growth. Incorporation of yeast extract in the tobacco-high-salts-medium produced the highest amount of growth and chlorophyll formation in endive tissue. Presence of exogenous sucrose was essential for the continued good growth of the above callus tissues in vitro. Highest amount of growth took place either in white light or in the dark. Different tissues had different responses to high or low intensities of light. Endive and carrot tissues produced in vitro were palatable to human taste. Endive tissue was particularly good as it also differentiated many small rosettes of leaves, shoots and had a mild aromatic flavor typical of the endive plants grown in nature.

  11. Successful tree planting techniques for drastically disturbed lands: A case study of the propagation planting of container-grown oak and nut trees in Missouri

    SciTech Connect

    Miller, S.

    1998-12-31

    Successful tree seedling establishment on drastically disturbed lands is contingent on seven major variables: (1) selection of proper native species, (2) purchase of the best quality planting stock, (3) correct handling of planting stock, (4) correct planting techniques, (5) effective control of competing vegetation, (6) proper soil conditions and preparation, (7) weather. Exotic species should not be planted to avoid past mistakes such as kudzu, Japanese honeysuckle, sericea lespedeza and chestnut blight. A major concern of reclamation specialists and ecosystem restorationists is obtaining high-quality plant materials with the correct provenance. Ecosystem restorationists, reclamation specialists, park managers and private landowners can easily and cheaply propagate native oak or other hardwood species from local parent stock using Whitcomb bottomless containers. Proper seed collection, storage and preparation techniques as well as propagation methods are critical for seedling growth and development into quality air-pruned planting stock. Air-pruned seedlings of local provenance can be outplanted in the fall after one growing season with little transplanting shock while developing extensive root systems prior to soil freezing in winter. Establishment success of container-grown seedlings greatly exceeds that of spring-planted bare-root seedlings. Fall-planted, container-grown seedlings have a decided advantage since their roots continue to grow throughout the fall and much of the winter, enabling them to better withstand summer drought and weedy competitors. Container-grown seedlings also allow a five- to six-month planting season compared to bare-root seedlings` four to six weeks. Since propagation costs are minimal, planters who grow their own save money on the planting stock. Because the quality is higher, home-grown seedlings have greater establishment success, saving labor, time and money. With better survival rates, far fewer trees need be planted as compared

  12. Amelioration of ozone-induced oxidative damage in wheat plants grown under high carbon dioxide: Role of antioxidant enzymes

    SciTech Connect

    Rao, M.V.; Hale, B.A.; Ormrod, D.P.

    1995-10-01

    O{sub 3}-induced in growth, oxidative damage to protein, and specific activities of certain antioxidant enzymes were investigated in wheat plants (Triticum aestivum L. cv Roblin) grown under ambient or high CO{sub 2}. High CO{sub 2} enhanced shoot biomass. The shoot biomass was relatively unaffected in plants grown under a combination of high CO{sub 2} and O{sub 3}. O{sub 3} exposure under ambient CO{sub 2} decreased photosynthetic pigments, soluble proteins, and ribulose-1,5-bisphosphate carboxylase/oxygenase protein and enhanced oxidative damage to proteins, but these effects were not observed in plants exposed to O{sub 3} under high CO{sub 2}. O{sub 3} exposure initially enhanced the specific activities of superoxide dismutase, peroxidase, glutathione reductase, and ascorbate peroxidase irrespective of growth in ambient or high CO{sub 2}. O{sub 3} exposure initially enhanced the specific activities of superoxide dismutase, peroxidase, glutathione reductase, and ascorbate peroxidase irrespective of growth in ambient or high CO{sub 2}. However, the specific activities decreased in plants with prolonged exposure to O{sub 3} under ambient CO{sub 2} but not in plants exposed to O{sub 3} under high CO{sub 2}. Native gels revealed preferential changes in the isoform composition of superoxide dismutase, peroxidases, and ascorbate peroxidase of plants grown under a combination of high CO{sub 2} and O{sub 3}. Furthermore, growth under high CO{sub 2} and O{sub 3} led to the synthesis of one new isoform of glutathione reductase. This could explain why plants grown under a combination of high CO{sub 2} and O{sub 3} are capable of resisting O{sub 3}-induced damage to growth and proteins compared to plants exposed to O{sub 3} under ambient CO{sub 2}. 66 refs., 8 figs., 1 tab.

  13. Composition and physical properties of starch in microgravity-grown plants

    NASA Astrophysics Data System (ADS)

    Kuznetsov, O. A.; Brown, C. S.; Levine, H. G.; Piastuch, W. C.; Sanwo-Lewandowski, M. M.; Hasenstein, K. H.

    2001-01-01

    The effect of spaceflight on starch development in soybean ( Glycine max L., BRIC-03) and potato ( Solanum tuberosum, Astroculture-05) was compared with ground controls by biophysical and biochemical measurements. Starch grains from plants from both flights were on average 20-50% smaller in diameter than ground controls. The ratio Δκ/Δρ (Δκ - difference of magnetic susceptibilities, Δρ - difference of densities between starch and water) of starch grains was ca. 15% and 4% higher for space-grown soybean cotyledons and potato tubers, respectively, than in corresponding ground controls. Since the densities of particles were similar for all samples (1.36 to 1.38 g/cm 3), the observed difference in Δκ/Δρ was due to different magnetic susceptibilities and indicates modified composition of starch grains. In starch preparations from soybean cotyledons (BRIC-03) subjected to controlled enzymatic degradation with α-amylase for 24 hours, 77±6% of the starch from the flight cotyledons was degraded compared to 58±12% in ground controls. The amylose content in starch was also higher in space-grown tissues. The good correlation between the amylose content and Δκ/Δρ suggests, that the magnetic susceptibility of starch grains is related to their amylose content. Since the seedlings from the BRIC-03 experiment showed elevated post-flight ethylene levels, material from another flight experiment (GENEX) which had normal levels of ethylene was examined and showed no difference to ground controls in size distribution, density, Δκ/Δρ and amylose content. Therefore the role of ethylene appears to be more important for changes in starch metabolism than microgravity.

  14. Composition and physical properties of starch in microgravity-grown plants.

    PubMed

    Kuznetsov, O A; Brown, C S; Levine, H G; Piastuch, W C; Sanwo-Lewandowski, M M; Hasenstein, K H

    2001-01-01

    The effect of spaceflight on starch development in soybean (Glycine max L., BRIC-03) and potato (Solanum tuberosum, Astroculture-05) was compared with ground controls by biophysical and biochemical measurements. Starch grains from plants from both flights were on average 20-50% smaller in diameter than ground controls. The ratio delta X/delta rho (delta X --difference of magnetic susceptibilities, delta rho--difference of densities between starch and water) of starch grains was ca. 15% and 4% higher for space-grown soybean cotyledons and potato tubers, respectively, than in corresponding ground controls. Since the densities of particles were similar for all samples (1.36 to 1.38 g/cm3), the observed difference in delta X/delta rho was due to different magnetic susceptibilities and indicates modified composition of starch grains. In starch preparations from soybean cotyledons (BRIC-03) subjected to controlled enzymatic degradation with alpha-amylase for 24 hours, 77 +/- 6% of the starch from the flight cotyledons was degraded compared to 58 +/- 12% in ground controls. The amylose content in starch was also higher in space-grown tissues. The good correlation between the amylose content and delta X/delta rho suggests, that the magnetic susceptibility of starch grains is related to their amylose content. Since the seedlings from the BRIC-03 experiment showed elevated post-flight ethylene levels, material from another flight experiment (GENEX) which had normal levels of ethylene was examined and showed no difference to ground controls in size distribution, density, delta X/delta rho and amylose content. Therefore the role of ethylene appears to be more important for changes in starch metabolism than microgravity.

  15. Composition and physical properties of starch in microgravity-grown plants

    NASA Technical Reports Server (NTRS)

    Kuznetsov, O. A.; Brown, C. S.; Levine, H. G.; Piastuch, W. C.; Sanwo-Lewandowski, M. M.; Hasenstein, K. H.; Sager, J. C. (Principal Investigator)

    2001-01-01

    The effect of spaceflight on starch development in soybean (Glycine max L., BRIC-03) and potato (Solanum tuberosum, Astroculture-05) was compared with ground controls by biophysical and biochemical measurements. Starch grains from plants from both flights were on average 20-50% smaller in diameter than ground controls. The ratio delta X/delta rho (delta X --difference of magnetic susceptibilities, delta rho--difference of densities between starch and water) of starch grains was ca. 15% and 4% higher for space-grown soybean cotyledons and potato tubers, respectively, than in corresponding ground controls. Since the densities of particles were similar for all samples (1.36 to 1.38 g/cm3), the observed difference in delta X/delta rho was due to different magnetic susceptibilities and indicates modified composition of starch grains. In starch preparations from soybean cotyledons (BRIC-03) subjected to controlled enzymatic degradation with alpha-amylase for 24 hours, 77 +/- 6% of the starch from the flight cotyledons was degraded compared to 58 +/- 12% in ground controls. The amylose content in starch was also higher in space-grown tissues. The good correlation between the amylose content and delta X/delta rho suggests, that the magnetic susceptibility of starch grains is related to their amylose content. Since the seedlings from the BRIC-03 experiment showed elevated post-flight ethylene levels, material from another flight experiment (GENEX) which had normal levels of ethylene was examined and showed no difference to ground controls in size distribution, density, delta X/delta rho and amylose content. Therefore the role of ethylene appears to be more important for changes in starch metabolism than microgravity. c2001 COSPAR. Published by Elsevier Science Ltd. All rights reserved.

  16. Multiwalled carbon nanotubes in alfalfa and wheat: toxicology and uptake.

    PubMed

    Miralles, Pola; Johnson, Errin; Church, Tamara L; Harris, Andrew T

    2012-12-07

    Data on the bioavailability and toxicity of carbon nanotubes (CNTs) in the environment, and, in particular, on their interactions with vascular plants, are limited. We investigated the effects of industrial-grade multiwalled CNTs (75 wt% CNTs) and their impurities on alfalfa and wheat. Phytotoxicity assays were performed during both seed germination and seedling growth. The germinations of both species were tolerant of up to 2560 mg l(-1) CNTs, and root elongation was enhanced in alfalfa and wheat seedlings exposed to CNTs. Remarkably, catalyst impurities also enhanced root elongation in alfalfa seedlings as well as wheat germination. Thus the impurities, not solely the CNTs, impacted the plants. CNT internalization by plants was investigated using electron microscopy and two-dimensional Raman mapping. The latter showed that CNTs were adsorbed onto the root surfaces of alfalfa and wheat without significant uptake or translocation. Electron microscopy investigations of internalization were inconclusive owing to poor contrast, so Fe(3)O(4)-functionalized CNTs were prepared and studied using energy-filter mapping of Fe(3)O(4). CNTs bearing Fe(3)O(4) nanoparticles were detected in the epidermis of one wheat root tip only, suggesting that internalization was possible but unusual. Thus, alfalfa and wheat tolerated high concentrations of industrial-grade multiwalled CNTs, which adsorbed onto their roots but were rarely taken up.

  17. Quantitative trait loci for early plant vigour of maize grown in chilly environments.

    PubMed

    Presterl, Thomas; Ouzunova, Milena; Schmidt, Walter; Möller, Evelyn M; Röber, Frank K; Knaak, Carsten; Ernst, Karin; Westhoff, Peter; Geiger, Hartwig H

    2007-04-01

    Maize (Zea mays L.) is particularly sensitive to chilling in the early growth stages. The objective of this study was to determine quantitative trait loci (QTL) for early plant vigour of maize grown under cool and moderately warm conditions in Central Europe. A population of 720 doubled haploid (DH) lines was derived from a cross between two dent inbred lines contrasting in early vigour and were genotyped with 188 SSR markers. The DH lines per se and their testcrosses with a flint line were evaluated in field experiments across 11 environments in 2001 and 2002. Plants were harvested after six to eight leaves had been fully developed to assess fresh matter yield as a criterion of early vigour. Seven QTL were detected for line performance and ten QTL for testcross performance, explaining 64 and 49% of the genetic variance. Six out of seven QTL detected in the lines per se were also significant in their testcrosses. Significant QTL x environment interaction was observed, but no relationship existed between the size of the QTL effects and the mean temperature in the individual environment. The correlation between fresh matter yield and days to silking was non-significant, indicating that differences in early plant vigour were not simply caused by maturity differences. For three additional chilling-related traits, leaf chlorosis, leaf purpling, and frost damage seven, six, and five QTL were detected, respectively. Three QTL for leaf chlorosis, two for leaf purpling, and two for frost damage co-localized with QTL for fresh matter yield. Results are considered as a reliable basis for further genetic, molecular, and physiological investigations.

  18. Drench Treatments for Management of Larval Japanese Beetle (Coleoptera: Scarabaeidae) in Field-Grown Balled and Burlapped Nursery Plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The study evaluated insecticide drenches applied to post-harvest field-grown nursery plants harvested as 60-cm diameter balled and burlapped (B&B) root balls for controlling third instar Japanese beetle, Popillia japonica Newman. Bifenthrin, chlorpyrifos, lambda-cyhalothrin, and thiamethoxam were d...

  19. Calcium localization in lettuce leaves with and without tipburn: comparison of controlled-environment and field-grown plants

    NASA Technical Reports Server (NTRS)

    Barta, D. J.; Tibbitts, T. W.

    1991-01-01

    An electron microprobe was used to determine tissue concentrations of Ca across 20-mm-long leaves of 'Green Lakes' crisphead lettuce (Lactuca sativa L.) with and without tipburn injury. Concentrations within the fifth and 14th leaves, counted from the cotyledons, from plants grown under controlled-environment conditions were compared to concentrations within similar leaves obtained from plants grown under field conditions. Only the 14th leaf from plants grown under controlled-environment conditions developed tipburn. Injured areas on these leaves had Ca concentrations as low as 0.2 to 0.3 mg g-1 dry weight. Uninjured areas of tipburned leaves contained from 0.4 to 0.5 mg g-1 dry weight. Concentrations across the uninjured 14th leaf from field-grown plants averaged 1.0 mg g-1 dry weight. Amounts across the uninjured fifth leaves from both environments averaged 1.6 mg g-1 dry weight. In contrast, Mg concentrations were higher in injured leaves than in uninjured leaves and thus were negatively correlated with Ca concentrations. Magnesium concentrations averaged 4.7 mg g-1 dry weight in injured leaves compared with 3.4 mg g-1 dry weight in uninjured leaves from both environments. Magnesium concentrations were uniform across the leaf. Potassium concentrations were highest at the leaf apex and decreased toward the base and also decreased from the midrib to the margin. Potassium averaged 51 mg g-1 dry weight in injured and uninjured leaves from both environments. No significant differences in K concentration were present between injured and uninjured leaves. This study documented that deficient concentrations of Ca were present in areas of leaf tissue developing tipburn symptoms and that concentrations were significantly higher in similar areas of other leaves that had no symptoms. This study also documented that Ca concentrations were significantly lower in enclosed leaves that exhibited tipburn symptoms than in exposed leaves that did not exhibit tipburn. Also, the

  20. Calcium localization in lettuce leaves with and without tipburn: comparison of controlled-environment and field-grown plants.

    PubMed

    Barta, D J; Tibbitts, T W

    1991-09-01

    An electron microprobe was used to determine tissue concentrations of Ca across 20-mm-long leaves of 'Green Lakes' crisphead lettuce (Lactuca sativa L.) with and without tipburn injury. Concentrations within the fifth and 14th leaves, counted from the cotyledons, from plants grown under controlled-environment conditions were compared to concentrations within similar leaves obtained from plants grown under field conditions. Only the 14th leaf from plants grown under controlled-environment conditions developed tipburn. Injured areas on these leaves had Ca concentrations as low as 0.2 to 0.3 mg g-1 dry weight. Uninjured areas of tipburned leaves contained from 0.4 to 0.5 mg g-1 dry weight. Concentrations across the uninjured 14th leaf from field-grown plants averaged 1.0 mg g-1 dry weight. Amounts across the uninjured fifth leaves from both environments averaged 1.6 mg g-1 dry weight. In contrast, Mg concentrations were higher in injured leaves than in uninjured leaves and thus were negatively correlated with Ca concentrations. Magnesium concentrations averaged 4.7 mg g-1 dry weight in injured leaves compared with 3.4 mg g-1 dry weight in uninjured leaves from both environments. Magnesium concentrations were uniform across the leaf. Potassium concentrations were highest at the leaf apex and decreased toward the base and also decreased from the midrib to the margin. Potassium averaged 51 mg g-1 dry weight in injured and uninjured leaves from both environments. No significant differences in K concentration were present between injured and uninjured leaves. This study documented that deficient concentrations of Ca were present in areas of leaf tissue developing tipburn symptoms and that concentrations were significantly higher in similar areas of other leaves that had no symptoms. This study also documented that Ca concentrations were significantly lower in enclosed leaves that exhibited tipburn symptoms than in exposed leaves that did not exhibit tipburn. Also, the

  1. Gene-Transformation-Induced Changes in Chemical Functional Group Features and Molecular Structure Conformation in Alfalfa Plants Co-Expressing Lc-bHLH and C1-MYB Transcriptive Flavanoid Regulatory Genes: Effects of Single-Gene and Two-Gene Insertion

    PubMed Central

    Heendeniya, Ravindra G.; Yu, Peiqiang

    2017-01-01

    Alfalfa (Medicago sativa L.) genotypes transformed with Lc-bHLH and Lc transcription genes were developed with the intention of stimulating proanthocyanidin synthesis in the aerial parts of the plant. To our knowledge, there are no studies on the effect of single-gene and two-gene transformation on chemical functional groups and molecular structure changes in these plants. The objective of this study was to use advanced molecular spectroscopy with multivariate chemometrics to determine chemical functional group intensity and molecular structure changes in alfalfa plants when co-expressing Lc-bHLH and C1-MYB transcriptive flavanoid regulatory genes in comparison with non-transgenic (NT) and AC Grazeland (ACGL) genotypes. The results showed that compared to NT genotype, the presence of double genes (Lc and C1) increased ratios of both the area and peak height of protein structural Amide I/II and the height ratio of α-helix to β-sheet. In carbohydrate-related spectral analysis, the double gene-transformed alfalfa genotypes exhibited lower peak heights at 1370, 1240, 1153, and 1020 cm−1 compared to the NT genotype. Furthermore, the effect of double gene transformation on carbohydrate molecular structure was clearly revealed in the principal component analysis of the spectra. In conclusion, single or double transformation of Lc and C1 genes resulted in changing functional groups and molecular structure related to proteins and carbohydrates compared to the NT alfalfa genotype. The current study provided molecular structural information on the transgenic alfalfa plants and provided an insight into the impact of transgenes on protein and carbohydrate properties and their molecular structure’s changes. PMID:28335521

  2. Gene-Transformation-Induced Changes in Chemical Functional Group Features and Molecular Structure Conformation in Alfalfa Plants Co-Expressing Lc-bHLH and C1-MYB Transcriptive Flavanoid Regulatory Genes: Effects of Single-Gene and Two-Gene Insertion.

    PubMed

    Heendeniya, Ravindra G; Yu, Peiqiang

    2017-03-20

    Alfalfa (Medicago sativa L.) genotypes transformed with Lc-bHLH and Lc transcription genes were developed with the intention of stimulating proanthocyanidin synthesis in the aerial parts of the plant. To our knowledge, there are no studies on the effect of single-gene and two-gene transformation on chemical functional groups and molecular structure changes in these plants. The objective of this study was to use advanced molecular spectroscopy with multivariate chemometrics to determine chemical functional group intensity and molecular structure changes in alfalfa plants when co-expressing Lc-bHLH and C1-MYB transcriptive flavanoid regulatory genes in comparison with non-transgenic (NT) and AC Grazeland (ACGL) genotypes. The results showed that compared to NT genotype, the presence of double genes (Lc and C1) increased ratios of both the area and peak height of protein structural Amide I/II and the height ratio of α-helix to β-sheet. In carbohydrate-related spectral analysis, the double gene-transformed alfalfa genotypes exhibited lower peak heights at 1370, 1240, 1153, and 1020 cm(-1) compared to the NT genotype. Furthermore, the effect of double gene transformation on carbohydrate molecular structure was clearly revealed in the principal component analysis of the spectra. In conclusion, single or double transformation of Lc and C1 genes resulted in changing functional groups and molecular structure related to proteins and carbohydrates compared to the NT alfalfa genotype. The current study provided molecular structural information on the transgenic alfalfa plants and provided an insight into the impact of transgenes on protein and carbohydrate properties and their molecular structure's changes.

  3. Bioaccumulation of triclosan and triclocarban in plants grown in soils amended with municipal dewatered biosolids.

    PubMed

    Prosser, Ryan S; Lissemore, Linda; Topp, Edward; Sibley, Paul K

    2014-05-01

    Biosolids generally contain the microbiocidal agents triclosan (TCS) and triclocarban (TCC) that are persistent during wastewater treatment and sorp to organic material. The present study investigated the concentration of TCS in tissues of radish, carrot, and soybean grown in potted soil amended with biosolids. Highest mean concentrations of TCS in radish, carrot, and soybean root tissue midway through the life cycle were 24.8 ng/g, 49.8 ng/g, and 48.1 ng/g dry weight, respectively; by the conclusion of the test, however, concentrations had declined to 2.1 ng/g, 5.5 ng/g, and 8.4 ng/g dry weight, respectively. Highest mean concentrations of TCS in radish and carrot shoot tissue were 33.7 and 18.3 ng/g dry weight at days 19 and 45, respectively, but had declined to 13.7 ng/g and 5.5 ng/g dry weight at days 34 and 69, respectively. Concentration of TCS in all samples of soybean seeds was below method detection limit (i.e., 2.8 ng/g dry wt). The present study also examined the concentration of TCS and TCC in edible portions of green pepper, carrot, cucumber, tomato, radish, and lettuce plants grown in a field amended with biosolids. Triclosan was detected only in cucumber and radish up to 5.2 ng/g dry weight. Triclocarban was detected in carrot, green pepper, tomato, and cucumber up to 5.7 ng/g dry weight. On the basis of the present study and other studies, we estimate that vegetable consumption represents less than 0.5% of the acceptable daily intake of TCS and TCC. These results demonstrate that, if best management practices for land application of biosolids in Ontario are followed, the concentration of TCS and TCC in edible portions of plants represents a negligible exposure pathway to humans.

  4. Aluminium-induced reduction of plant growth in alfalfa (Medicago sativa) is mediated by interrupting auxin transport and accumulation in roots.

    PubMed

    Wang, Shengyin; Ren, Xiaoyan; Huang, Bingru; Wang, Ge; Zhou, Peng; An, Yuan

    2016-07-20

    The objective of this study was to investigate Al(3+)-induced IAA transport, distribution, and the relation of these two processes to Al(3+)-inhibition of root growth in alfalfa. Alfalfa seedlings with or without apical buds were exposed to 0 or 100 μM AlCl3 and were foliar sprayed with water or 6 mg L(-1) IAA. Aluminium stress resulted in disordered arrangement of cells, deformed cell shapes, altered cell structure, and a shorter length of the meristematic zone in root tips. Aluminium stress significantly decreased the IAA concentration in apical buds and root tips. The distribution of IAA fluorescence signals in root tips was disturbed, and the IAA transportation from shoot base to root tip was inhibited. The highest intensity of fluorescence signals was detected in the apical meristematic zone. Exogenous application of IAA markedly alleviated the Al(3+)-induced inhibition of root growth by increasing IAA accumulation and recovering the damaged cell structure in root tips. In addition, Al(3+) stress up-regulated expression of AUX1 and PIN2 genes. These results indicate that Al(3+)-induced reduction of root growth could be associated with the inhibitions of IAA synthesis in apical buds and IAA transportation in roots, as well as the imbalance of IAA distribution in root tips.

  5. Aluminium-induced reduction of plant growth in alfalfa (Medicago sativa) is mediated by interrupting auxin transport and accumulation in roots

    PubMed Central

    Wang, Shengyin; Ren, Xiaoyan; Huang, Bingru; Wang, Ge; Zhou, Peng; An, Yuan

    2016-01-01

    The objective of this study was to investigate Al3+-induced IAA transport, distribution, and the relation of these two processes to Al3+-inhibition of root growth in alfalfa. Alfalfa seedlings with or without apical buds were exposed to 0 or 100 μM AlCl3 and were foliar sprayed with water or 6 mg L−1 IAA. Aluminium stress resulted in disordered arrangement of cells, deformed cell shapes, altered cell structure, and a shorter length of the meristematic zone in root tips. Aluminium stress significantly decreased the IAA concentration in apical buds and root tips. The distribution of IAA fluorescence signals in root tips was disturbed, and the IAA transportation from shoot base to root tip was inhibited. The highest intensity of fluorescence signals was detected in the apical meristematic zone. Exogenous application of IAA markedly alleviated the Al3+-induced inhibition of root growth by increasing IAA accumulation and recovering the damaged cell structure in root tips. In addition, Al3+ stress up-regulated expression of AUX1 and PIN2 genes. These results indicate that Al3+-induced reduction of root growth could be associated with the inhibitions of IAA synthesis in apical buds and IAA transportation in roots, as well as the imbalance of IAA distribution in root tips. PMID:27435109

  6. Transgene silencing of sucrose synthase in alfalfa stem vascular tissue by a truncated phosphoenolpyruvate carboxylase: sucrose synthase construct

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An important role of sucrose synthase (SUS, EC 2.4.1.13) in plants is to provide UDP-glucose needed for cellulose synthesis in cell walls. We examined if over-expressing SUS in alfalfa (Medicago sativa L.) would increase cellulose content of stem cell walls. Alfalfa plants were transformed with two ...

  7. European corn borer (Lepidoptera: Crambidae) infestation level and plant growth stage on whole-plant corn yield grown for silage in Virginia.

    PubMed

    Tiwari, S; Youngman, R R; Laub, C A; Brewster, C C; Jordan, T A; Teutsch, C

    2009-12-01

    Field experiments were conducted in 2004 and 2005 to determine the effect of different levels of hand-infested third instar European corn borer, Ostrinia nubilalis (Hiibner) (Lepidoptera: Crambidae), on whole-plant yield and plant growth stage in corn, Zea mays L., grown for silage. In 2004 and 2005, European corn borer infestation level had a significant negative impact on whole-plant yield (grams of dry matter per plant) with increasing infestation; however, whole-plant yield was not significantly affected by plant growth stage in either year. In 2004, the six larvae per plant treatment caused the greatest percentage of reduction (23.4%) in mean (+/-SEM) whole-plant yield (258.5 +/- 21.0 g dry matter per plant) compared with the Bacillus thuringiensis (Bt) CrylAb control (337.3 +/- 11.1 g dry matter per plant). In 2005, the five larvae per plant treatment caused the greatest percentage of reduction (8.3%) in mean whole-plant yield (282.3 +/- 10.8 g dry matter per plant) compared with the Bt CrylAb control (307.8 +/- 8.3 g dry matter per plant). The relationship between mean whole-plant yield and European corn borer larvae infestation level from the pooled data of both years was described well by using an exponential decay model (r2 = 0.84, P = 0.0038). The economic injury level for silage corn was estimated to be approximately 73% higher than for corn grown for grain based on similar control costs and crop values. In addition, plant growth stage and European corn borer infestation level had no effect on percentage of acid detergent fiber, neutral detergent fiber, and crude protein values in either year of the study.

  8. Heavy metal accumulation in wheat plant grown in soil amended with industrial sludge.

    PubMed

    Bose, Sutapa; Bhattacharyya, A K

    2008-01-01

    The concentrations of different forms of Zn, Cu, Mn, Ni, Cd, Cr, Pb and Fe metals were determined for the roadside sludge collected from pickling-rolling and electroplating industrial area. In sludge the relative abundance of total heavy metals were Fe>Mn>Cr>Ni>Cu>Pb>Zn>Cd and DTPA-extractable metals were in the order--Fe>Ni>Mn>Cr>Cu>Zn>Pb>Cd. Pot-culture experiment was conducted in soils amended with sludge (0%, 10%, 20%, 30%), pretreated with lime (0%, 0.5% and 1%). The soils were alkaline in nature (pH>8.3) with organic carbon contents were 0.34% and 0.72%. The most abundant total and bio-available metal was Fe. Two wheat seedlings were grown in each pot containing 3kg sludge-amended or control soil and the experiment was conducted till harvesting. Application of sludge increased both total and bio-available forms of metals in the soils, while lime application decreased the bioavailability of heavy metals in sludge-amended soils. The content of organic carbon showed positive correlation with all metals except Zn, Cr and Pb. CEC also showed a strong positive correlation (R2>0.7) with Fe, Mn, Cu, Ni and Cd. Though wheat plants are not accumulators, the translocation efficiency was appreciably high. The translocation factor from shoot to grain was found smaller than that of root to shoot of wheat plants. This makes an implication that the heavy metal accumulation was proportionally lesser in grain than in shoot. In, 10% sludge with 0.5% lime-amended soils; each of these toxic heavy metals was found to be within permissible range (USEPA). Hence, on the basis of present study, the best possible treatment may be recommended.

  9. Alfalfa (Medicago sativa L.) shoot saponins: identification and bio-activity by the assessment of aphid feeding.

    PubMed

    Mazahery-Laghab, H; Yazdi-Samadi, B; Bagheri, M; Bagheri, A R

    2011-01-01

    Biochemical components in alfalfa (Medicago sativa L.), such as saponins, can act as protecting factors against bio-stresses. Saponins are also antifeedants and show oral toxicity towards higher and lower animals. Changes in saponins, such as variation in the carbon skeleton, or hydrolysis of saponin glycosides and other conjugates, may change their biological effects. The aims of this research were to study saponin variation in different growth stages of alfalfa and to investigate the biological role of saponins in the spotted alfalfa aphid, Therioaphis maculata. Saponins from alfalfa shoots in different growth stages were extracted, chemically purified and analysed by TLC. Specific saponins such as soyasaponin1 from root and shoot and two bisdesmosides of medicagenic acid, one from shoot and another from root tissues, were identified using reference compounds allowing changes in saponin composition during plant development in different shoot tissues of alfalfa to be assessed. The response of the alfalfa aphid to feeding on alfalfa in different growth stages was studied. No significant difference in the survival of aphids, from neonate to adult, was observed, but due to the antibiotic effects of saponins, two differences were found in the onset of nymph production and cumulative nymph production. The results show that the saponin composition in alfalfa changes with plant development and this, in turn, can often negatively affect the development of specific insect pests such as the spotted alfalfa aphid, suggesting a possible biological role of alfalfa saponins.

  10. Stress responses in alfalfa (Medicago sativa L. )

    SciTech Connect

    Kessmann, H.; Edwards, R.; Dixon, R.A. ); Geno, P.W. )

    1990-09-01

    The isoflavonoid conjugates medicarpin-3-O-glucoside-6{double prime}-O-malonate (MGM), afrormosin-7-O-glucoside (AG), and afrormosin-7-O-glucoside-6{double prime}-O-malonate (AGM) were isolated and characterized from cell suspension cultures of alfalfa (Medicago sativa L.), where they were the major constitutive secondary metabolites. They were also found in alfalfa roots but not in other parts of the plant. The phytoalexin medicarpin accumulated rapidly in suspension cultured cells treated with elicitor from Colletotrichum lindemuthianum, and this was subsequently accompanied by an increase in the levels of MGM. In contrast, net accumulation of afrormosin conjugates was not affected by elicitor treatment. Labeling studies with ({sup 14}C)phenylalanine indicated that afrormosin conjugates were the major de novo synthesized isoflavonoid products in unelicited cells. During elicitation, ({sup 14}C)phenylalanine was incorporated predominantly into medicarpin, although a significant proportion of the newly synthesized medicarpin was also conjugated. Treatment of {sup 14}C-labeled, elicited cells with L-{alpha}-aminooxy-{beta}-phenylpropionic acid, a potent inhibitor of PAL activity in vivo, resulted in the initial appearance of labeled medicarpin of very low specific activity, suggesting that the phytoalexin could be released from a preformed conjugate under these conditions. Our data draw attention to the involvement of isoflavone hydroxylases during the constitutive and elicitor-induced accumulation of isoflavonoids and their conjugates in alfalfa cell cultures.

  11. Proteome Changes in Penicillium expansum Grown in a Medium Derived from Host Plant.

    PubMed

    Xia, Xiaoshuang; Li, Huan; Liu, Fei; Zhang, Ye; Zhang, Qi; Wang, Yun; Li, Peiwu

    2017-03-28

    Penicillium expansum causes blue mold rot, a prevalent postharvest disease of pome fruit, and is also the main producer of the patulin. However, knowledge on the molecular mechanisms involved in this pathogen-host interaction remains largely unknown. In this work, a two-dimensional gel electrophoresis-based proteomic approach was applied to probe changes in P. expansum 3.3703 cultivated in apple juice medium, which was used to mimic the in planta condition. The results showed that the pH value and reducing sugar content in the apple juice medium decreased whereas the patulin content increased with the growing of P. expansum. A total of 28 protein spots that were up-regulated in P. expansum when grown in apple juice medium were identified. Functional categorization revealed that the identified proteins were mainly related to carbohydrate metabolism, secondary metabolism, protein biosynthesis or degradation, and redox homeostasis. Remarkably, several induced proteins, including glucose dehydrogenase, galactose oxidase, and FAD-binding monooxygenase, which might be responsible for the observed medium acidification and patulin production, were also detected. Overall, the experimental results provide a comprehensive interpretation of the physiological and proteomic responses of P. expansum to the host plant environment, and future functional characterization of the identified proteins will deepen our understanding of fungi-host interactions.

  12. Disposal options for polluted plants grown on heavy metal contaminated brownfield lands - A review.

    PubMed

    Kovacs, Helga; Szemmelveisz, Katalin

    2017-01-01

    Reducing or preventing damage caused by environmental pollution is a significant goal nowadays. Phytoextraction, as remediation technique is widely used, but during the process, the heavy metal content of the biomass grown on these sites special treatment and disposal techniques are required, for example liquid extraction, direct disposal, composting, and combustion. These processes are discussed in this review in economical and environmental aspects. The following main properties are analyzed: form and harmful element content of remains, utilization of the main and byproducts, affect to the environment during the treatment and disposal. The thermal treatment (combustion, gasification) of contaminated biomass provides a promising alternative disposal option, because the energy production affects the rate of return, and the harmful elements are riched in a small amount of solid remains depending on the ash content of the plant (1-2%). The biomass combustion technology is a wildely used energy production process in residential and industrial scale, but the ordinary biomass firing systems are not suited to burn this type of fuel without environmental risk.

  13. Occurrence of alfalfa (Medicago sativa L.) populations along roadsides in southern Manitoba, Canada and their potential role in intraspecific gene flow.

    PubMed

    Bagavathiannan, Muthukumar V; Gulden, Robert H; Van Acker, Rene C

    2011-04-01

    Alfalfa is a highly outcrossing perennial species that can be noticed in roadsides as feral populations. There remains little information available on the extent of feral alfalfa populations in western Canadian prairies and their role in gene flow. The main objectives of this study were (a) to document the occurrence of feral alfalfa populations, and (b) to estimate the levels of outcrossing facilitated by feral populations. A roadside survey confirmed widespread occurrence of feral alfalfa populations, particularly in alfalfa growing regions. The feral populations were dynamic and their frequency ranged from 0.2 to 1.7 populations km(-1). In many cases, the nearest feral alfalfa population from alfalfa production field was located within a distance sufficient for outcrossing in alfalfa. The gene flow study confirmed that genes can move back and forth between feral and cultivated alfalfa populations. In this study, the estimated outcrossing levels were 62% (seed fields to feral), 78% (feral to seed fields), 82% (hay fields to feral) and 85% (feral to feral). Overall, the results show that feral alfalfa plants are prevalent in alfalfa producing regions in western Canada and they can serve as bridges for gene flow at landscape level. Management of feral populations should be considered, if gene flow is a concern. Emphasis on preventing seed spill/escapes and intentional roadside planting of alfalfa cultivars will be particularly helpful. Further, realistic and pragmatic threshold levels should be established for markets sensitive to the presence of GE traits.

  14. The Mouthparts Enriched Odorant Binding Protein 11 of the Alfalfa Plant Bug Adelphocoris lineolatus Displays a Preferential Binding Behavior to Host Plant Secondary Metabolites

    PubMed Central

    Sun, Liang; Wei, Yu; Zhang, Dan-Dan; Ma, Xiao-Yu; Xiao, Yong; Zhang, Ya-Nan; Yang, Xian-Ming; Xiao, Qiang; Guo, Yu-Yuan; Zhang, Yong-Jun

    2016-01-01

    Odorant binding proteins (OBPs) are proposed to be directly required for odorant discrimination and represent potential interesting targets for pest control. In the notoriously agricultural pest Adelphocoris lineolatus, our previous functional investigation of highly expressed antennal OBPs clearly supported this viewpoint, whereas the findings of the current study by characterizing of AlinOBP11 rather indicated that OBP in hemipterous plant bugs might fulfill a different and tantalizing physiological role. The phylogenetic analysis uncovered that AlinOBP11 together with several homologous bug OBP proteins are potential orthologs, implying they could exhibit a conserved function. Next, the results of expression profiles solidly showed that AlinOBP11 was predominantly expressed at adult mouthparts, the most important gustatory organ of Hemiptera mirid bug. Finally, a rigorously selective binding profile was observed in the fluorescence competitive binding assay, in which recombinant AlinOBP11 displayed much stronger binding abilities to non-volatile secondary metabolite compounds than the volatile odorants. These results reflect that AlinOBP11, even its orthologous proteins across bug species, could be associated with a distinctively conserved physiological role such as a crucial carrier for non-volatiles host secondary metabolites in gustatory system. PMID:27313540

  15. Photomorphogenesis, photosynthesis, and seed yield of wheat plants grown under red light-emitting diodes (LEDs) with and without supplemental blue lighting

    NASA Technical Reports Server (NTRS)

    Goins, G. D.; Yorio, N. C.; Sanwo, M. M.; Brown, C. S.; Sager, J. C. (Principal Investigator)

    1997-01-01

    Red light-emitting diodes (LEDs) are a potential light source for growing plants in spaceflight systems because of their safety, small mass and volume, wavelength specificity, and longevity. Despite these attractive features, red LEDs must satisfy requirements for plant photosynthesis and photomorphogenesis for successful growth and seed yield. To determine the influence of gallium aluminium arsenide (GaAlAs) red LEDs on wheat photomorphogenesis, photosynthesis, and seed yield, wheat (Triticum aestivum L., cv. 'USU-Super Dwarf') plants were grown under red LEDs and compared to plants grown under daylight fluorescent (white) lamps and red LEDs supplemented with either 1% or 10% blue light from blue fluorescent (BF) lamps. Compared to white light-grown plants, wheat grown under red LEDs alone demonstrated less main culm development during vegetative growth through preanthesis, while showing a longer flag leaf at 40 DAP and greater main culm length at final harvest (70 DAP). As supplemental BF light was increased with red LEDs, shoot dry matter and net leaf photosynthesis rate increased. At final harvest, wheat grown under red LEDs alone displayed fewer subtillers and a lower seed yield compared to plants grown under white light. Wheat grown under red LEDs+10% BF light had comparable shoot dry matter accumulation and seed yield relative to wheat grown under white light. These results indicate that wheat can complete its life cycle under red LEDs alone, but larger plants and greater amounts of seed are produced in the presence of red LEDs supplemented with a quantity of blue light.

  16. Beneficial effects of silicon on hydroponically grown corn salad (Valerianella locusta (L.) Laterr) plants.

    PubMed

    Gottardi, Stefano; Iacuzzo, Francesco; Tomasi, Nicola; Cortella, Giovanni; Manzocco, Lara; Pinton, Roberto; Römheld, Volker; Mimmo, Tanja; Scampicchio, Matteo; Dalla Costa, Luisa; Cesco, Stefano

    2012-07-01

    Soil-less cultivation of horticultural crops represents a fairly recent innovation to traditional agriculture which has several advantages including higher water-use efficiency. When plants are grown with this system, their roots come in contact with nutrients solely via the hydroponic solution. Although its beneficial effects have been widely demonstrated, silicon (Si) is mostly omitted from the composition of nutrient solutions. Therefore, the objective of this study was to assess the beneficial effect of Si addition to hydroponic solution on quali-quantitative aspects of edible production of two cultivars of corn salad (Valerianella locusta (L.) Laterr.) grown in soil-less floating system. Impacts on shelf life of this food were also studied. Results show that the supply of Si increased the edible yield and the quality level reducing the nitrate concentration in edible tissues. This result might be attributed to changes either in the metabolism (such as the nitrate assimilation process) or to the functionality of root mechanisms involved in the nutrient acquisition from the outer medium. In fact, our results show for the first time the ability of Si to modulate the root activity of nitrate and Fe uptake through, at least in part, a regulation of gene expression levels of the proteins involved in this phenomenon. In addition, the presence of Si decreased the levels of polyphenoloxidase gene expression at harvest and, in post-harvest, slowed down the chlorophyll degradation delaying leaf senescence and thus prolonging the shelf life of these edible tissues. In conclusion, data showed that the addition of Si to the nutrient solution can be a useful tool for improving quali-quantitatively the yield of baby leaf vegetable corn salad as well as its shelf life. Since the amelioration due to the Si has been achieved only with one cultivar, the recommendation of its inclusion in the nutrient solution does not exclude the identification of cultivars suitable for this

  17. Elevated CO2 concentration around alfalfa nodules increases N2 fixation.

    PubMed

    Fischinger, Stephanie A; Hristozkova, Marieta; Mainassara, Zaman-Allah; Schulze, Joachim

    2010-01-01

    Nodule CO2 fixation via PEPC provides malate for bacteroids and oxaloacetate for N assimilation. The process is therefore of central importance for efficient nitrogen fixation. Nodule CO2 fixation is known to depend on external CO2 concentration. The hypothesis of the present paper was that nitrogen fixation in alfalfa plants is enhanced when the nodules are exposed to elevated CO2 concentrations. Therefore nodulated plants of alfalfa were grown in a hydroponic system that allowed separate aeration of the root/nodule compartment that avoided any gas leakage to the shoots. The root/nodule compartments were aerated either with a 2500 microl l(-1) (+CO2) or zero microl l(-1) (-CO2) CO2-containing N2/O2 gas flow (80/20, v/v). Nodule CO2 fixation, nitrogen fixation, and growth were strongly increased in the +CO2 treatment in a 3-week experimental period. More intensive CO2 and nitrogen fixation coincided with higher per plant amounts of amino acids and organic acids in the nodules. Moreover, the concentration of asparagine was increased in both the nodules and the xylem sap. Plants in the +CO2 treatment tended to develop nodules with higher %N concentration and individual activity. In a parallel experiment on plants with inefficient nodules (fix-) the +CO2 treatment remained without effect. Our data support the thesis that nodule CO2 fixation is pivotal for efficient nitrogen fixation. It is concluded that strategies which enhance nodule CO2 fixation will improve nitrogen fixation and nodule formation. Moreover, sufficient CO2 application to roots and nodules is necessary for growth and efficient nitrogen fixation in hydroponic and aeroponic growth systems.

  18. Growth and feeding response of Pseudoplusia includens (Lepidoptera:Noctuidae) to host plants grown in controlled carbon dioxide atmospheres

    SciTech Connect

    Lincoln, D.E.; Sionit, N.; Strain, B.R.

    1984-12-01

    Rising atmospheric carbon dioxide may alter plant/herbivore interactions. The projected rise in atmospheric carbon dioxide is expected to increase plant productivity, but little evidence is available regarding effects on insect feeding or growth. Leaves of soybean plants grown under three carbon dioxide regimes (350, 500, and 650 ..mu..l/liter) were fed to soybean looper larvae. Larvae fed at increasingly higher rates on plants from elevated carbon dioxide atmospheres: 80% greater rates on leaves from the 650 ..mu..l/liter treatment than on leaves from the 350 ..mu..l/litter treatment. Variation in larval feeding was related to the leaf content of nitrogen and water and to the leaf-specific weight, each of which was altered by the carbon dioxide growth regime of the soybean plants. This study suggests that the impact of herbivores may increase as the level of atmospheric carbon dioxide rises.

  19. Characterization of alfalfa populations contrasting for root system architecture (RSA)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The root system architecture affects the capacity for nutrient and water uptake thus impacting biomass yield production and may contribute to the persistence of perennial plants. The objectives of this study were to phenotype the roots of three alfalfa populations and identify differences between di...

  20. Diversity of field isolates of sinorhizobium meliloti nodulating alfalfa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Most alfalfa seed is treated with a rhizobial inoculant consisting of one or more strains of Sinorhizobium meliloti before planting to enhance nodulation of seedlings. However, little is known about the persistence of inoculated strains later in the season. There is also a paucity of information on ...

  1. Efficacy of gamma radiation and aqueous chlorine on Escherichia coli O157:H7 in hydroponically grown lettuce plants.

    PubMed

    Nthenge, Agnes K; Weese, Jean S; Carter, Melvin; Wei, Cheng-I; Huang, Tung-Shi

    2007-03-01

    Interaction of Escherichia coli O157:H7/pGFP with hydroponically grown lettuce plants was evaluated in this study. Lettuce seedlings were planted in contaminated Hoagland's nutrient solution and thereafter subjected to gamma radiation at 0.25, 0.5, and 0.75 kGy, and aqueous chlorine at 200 ppm. There was no trace of E. coli O157:H7/pGFP in lettuce leaves harvested from noncontaminated nutrient solution (control); however, for plants grown in contaminated nutrient solution, the pathogen was recovered from the leaves disinfected with 80% ethanol and 0.1% mercuric chloride. Most of the lettuce seedlings grown in contaminated nutrient solution tested negative for E. coli O157:H7/pGFP under controlled conditions. Gamma radiation at 0.25 and 0.5 kGy, and aqueous chlorine at 200 ppm failed to eliminate E. coli O157:H7/pGFP in lettuce tissue completely; however, the bacteria were not detected in 0.75-kGy treated plants. The presence of E. coli O157:H7/pGFP in lettuce leaves is an indication that the pathogen migrated from the contaminated hydroponic system through the roots to the internal locations of lettuce tissue. Due to inaccessibility and limited penetrating power, aqueous chlorine could not eliminate the bacteria localized in the internal tissue. Findings from this study suggest that gamma irradiation was more efficacious than was aqueous chlorine to control internal contamination in hydroponically grown lettuce. Gamma irradiation is a process that processors can use to inactivate E. coli O157:H7 and therefore, consumers benefit from a safer food product [corrected

  2. Genome-wide expression analysis of reactive oxygen species gene network in Mizuna plants grown in long-term spaceflight

    PubMed Central

    2014-01-01

    Background Spaceflight environment have been shown to generate reactive oxygen species (ROS) and induce oxidative stress in plants, but little is known about the gene expression of the ROS gene network in plants grown in long-term spaceflight. The molecular response and adaptation to the spaceflight environment of Mizuna plants harvested after 27 days of cultivation onboard the International Space Station (ISS) were measured using genome-wide mRNA expression analysis (mRNA-Seq). Results Total reads of transcripts from the Mizuna grown in the ISS as well as on the ground by mRNA-Seq showed 8,258 and 14,170 transcripts up-regulated and down-regulated, respectively, in the space-grown Mizuna when compared with those from the ground-grown Mizuna. A total of 20 in 32 ROS oxidative marker genes were up-regulated, including high expression of four hallmarks, and preferentially expressed genes associated with ROS-scavenging including thioredoxin, glutaredoxin, and alternative oxidase genes. In the transcription factors of the ROS gene network, MEKK1-MKK4-MPK3, OXI1-MKK4-MPK3, and OXI1-MPK3 of MAP cascades, induction of WRKY22 by MEKK1-MKK4-MPK3 cascade, induction of WRKY25 and repression of Zat7 by Zat12 were suggested. RbohD and RbohF genes were up-regulated preferentially in NADPH oxidase genes, which produce ROS. Conclusions This large-scale transcriptome analysis revealed that the spaceflight environment induced oxidative stress and the ROS gene network activation in the space-grown Mizuna. Among transcripts altered in expression by space conditions, some were common genes response to abiotic and biotic stress. Furthermore, certain genes were exclusively up-regulated in Mizuna grown on the ISS. Surprisingly, Mizuna grew in space normally, as well as on the ground, demonstrating that plants can acclimate to long-term exposure in the spaceflight environment by reprogramming the expression of the ROS gene network. PMID:24393219

  3. Isolation of RNA from field-grown jute (Corchorus capsularis) plant in different developmental stages for effective downstream molecular analysis.

    PubMed

    Samanta, Pradipta; Sadhukhan, Sanjoy; Das, Subrata; Joshi, Alpana; Sen, Soumitra K; Basu, Asitava

    2011-10-01

    Jute (Corchorus capsularis), as a natural fibre producing plant species, ranks next to cotton only. Today, biotechnological approach has been considered as most accepted means for any genetic improvement of plant species. However, genetic control of the fibre development in jute has not yet been explored sufficiently for desired genetic improvement. One of the major impediments in exploring the genetic architecture in this crop at molecular level is the availability of good quality RNA from field-grown plant tissues mostly due to the presence of high amount of mucilage and phenolics. Development of a suitable RNA isolation method is becoming essential for deciphering developmental stage-specific gene expression pattern related to fibre formation in this crop species. A combination of modified hot borate buffer followed by isopycnic centrifugation (termed as HBIC) was adopted and found to be the best isolation method yielding sufficient quantity (~350-500 μg/gm fresh tissue) and good quality (A(260/280) ratio 1.88 to 1.91) RNA depending on the developmental stage of stem tissue from field-grown jute plant. The poly A(+) RNA purified from total RNA isolated by the present method was found amenable to efficient RT-PCR and cDNA library construction. The present development of RNA isolation was found to be appropriate for gene expression analysis related to fibre formation in this economically important jute plant in near future.

  4. Developmental patterns of jicama (Pachyrhizus erosus (L.) Urban) plant and the chemical constituents of roots grown in Sonora, Mexico.

    PubMed

    Fernandez, M V; Warid, W A; Loaiza, J M; Montiel, A

    1997-01-01

    The developmental pattern of jicama (Pachyrhizus erosus (L.) Urban) was studied by sampling plants aged 20 to 36 weeks at weekly intervals. There was an increase in all characteristics of foliage: fresh and dry weight, number of leaves per plant, main stem length, number of leaves, nodes and internodes of the main stem; and in all root characteristics: fresh and dry weight, diameter and length. The chemical analysis was determined for roots at different plant ages. The range values for dry matter were 16.19-22.28%, protein 1.11-1.62%, fat 0.553-0.867%, crude fiber 0.3048-0.3943%, and ash 0.669-1.089%. The chemical constituents fluctuated with age but without specific trends. These values are considered the first record of roots produced by plants grown in Mexico.

  5. Microbiological Quality and Food Safety of Plants Grown on ISS Project

    NASA Technical Reports Server (NTRS)

    Wheeler, Raymond M. (Compiler)

    2014-01-01

    The goal of this project is to select and advance methods to enable real-time sampling, microbiological analysis, and sanitation of crops grown on the International Space Station (ISS). These methods would validate the microbiological quality of crops grown for consumption to ensure safe and palatable fresh foods. This would be achieved through the development / advancement of microbiological sample collection, rapid pathogen detection and effective sanitation methods that are compatible with a microgravity environment.

  6. Variation in alfalfa leafcutting bee (hymenoptera: megachilidae) reproductive success according to location of nests in United States commercial domiciles.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Low, medium, and high stocking densities of Megachile rotundata, the alfalfa leafcutting bee, were released over four years in three research plots of Utah alfalfa planted at seed-production rates. A low number of bees (46-79% of released) survived the incubation and field emergence processes, and ...

  7. Alfalfa varieties differ markedly in seedling survival when interseeded into corn and treated with prohexadione-calcium

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Interseeded alfalfa could serve as a dual purpose crop for providing groundcover during silage corn production and forage during subsequent years of production, but this system has been unworkable because competition between the co-planted crops often leads to stand failure of interseeded alfalfa. R...

  8. Uptake of perfluoroalkyl substances and halogenated flame retardants by crop plants grown in biosolids-amended soils.

    PubMed

    Navarro, Irene; de la Torre, Adrián; Sanz, Paloma; Porcel, Miguel Ángel; Pro, Javier; Carbonell, Gregoria; Martínez, María de Los Ángeles

    2017-01-01

    The bioaccumulation behavior of perfluoroalkyl substances (PFASs) and halogenated flame retardants (HFRs) was examined in three horticultural crops and earthworms. Two species, spinach (Spinacia oleracea) and tomato (Solanum lycopersicum L.), were grown in field soil amended with a single application of biosolids (at agronomic rate for nitrogen), to represent the scenario using commercial biosolids as fertilizer, and the third crop, corn (Zea mays) was grown in spiked soil (~50mg PFOS/kg soil, ~5mg Deca-BDE/kg soil and a mixture of both, ~50mg PFOS and ~5mg Deca-BDE/kg soil) to represent a worst-case scenario. To examine the bioaccumulation in soil invertebrates, earthworms (Eisenia andrei) were exposed to the spiked soil where corn had been grown. PFASs and HFRs were detected in the three crops and earthworms. To evaluate the distribution of the compounds in the different plant tissues, transfer factors (TFs) were calculated, with TF values higher for PFASs than PBDEs in all crop plants: from 2 to 9-fold in spinach, 2 to 34-fold in tomato and 11 to 309-fold in corn. Bioaccumulation factor (BAF) values in earthworms were also higher for PFASs (4.06±2.23) than PBDEs (0.02±0.02).

  9. Genome-Wide Expression Analysis of Reactive Oxygen Species Gene Network in Mizuna Plants Grown in Long-Term Spaceflight

    NASA Astrophysics Data System (ADS)

    Sugimoto, Manabu; Gusev, Oleg; Wheeler, Raymond; Levinskikh, Margarita; Sychev, Vladimir; Bingham, Gail; Hummerick, Mary; Oono, Youko; Matsumoto, Takashi; Yazawa, Takayuki

    We have developed a plant growth system, namely Lada, which was installed in ISS to study and grow plants, including vegetables in a spaceflight environment. We have succeeded in cultivating Mizuna, tomato, pea, radish, wheat, rice, and barley in long-term spaceflight. Transcription levels of superoxide dismutase, glutamyl transferase, catalase, and ascorbate peroxidase were increased in the barley germinated and grown for 26 days in Lada, though the whole-plant growth and development of the barley in spaceflight were the same as in the ground control barley. In this study, we investigated the response of the ROS gene network in Mizuna, Brassica rapa var. nipposinica, cultivated under spaceflight condition. Seeds of Mizuna were sown in the root module of LADA aboard the Zvezda module of ISS and the seedlings were grown under 24h lighting in the leaf chamber. After 27 days of cultivation, the plants were harvested and stored at -80(°) C in MELFI aboard the Destiny module, and were transported to the ground at < -20(°) C in GLACIER aboard Space Shuttle. Ground control cultivation was carried out under the same conditions in LADA. Total RNA isolated from leaves was subjected to mRNA-Seq using next generation sequencing (NGS) technology. A total of 20 in 32 ROS oxidative marker genes were up-regulated, including high expression of four hallmarks, and preferentially expressed genes associated with ROS-scavenging including thioredoxin, glutaredoxin, and alternative oxidase genes. In the transcription factors of the ROS gene network, MEKK1-MKK4-MPK3, OXI1-MKK4-MPK3, and OXI1-MPK3 of MAP cascades, induction of WRKY22 by MEKK1-MKK4-MPK3 cascade, induction of WRKY25 and repression of Zat7 by Zat12 were suggested. These results revealed that the spaceflight environment induced oxidative stress and the ROS gene network activation in the space-grown Mizuna.

  10. Novel components of leaf bacterial communities of field-grown tomato plants and their potential for plant growth promotion and biocontrol of tomato diseases.

    PubMed

    Romero, Fernando M; Marina, María; Pieckenstain, Fernando L

    2016-04-01

    This work aimed to characterize potentially endophytic culturable bacteria from leaves of cultivated tomato and analyze their potential for growth promotion and biocontrol of diseases caused by Botrytis cinerea and Pseudomonas syringae. Bacteria were obtained from inner tissues of surface-disinfected tomato leaves of field-grown plants. Analysis of 16S rRNA gene sequences identified bacterial isolates related to Exiguobacterium aurantiacum (isolates BT3 and MT8), Exiguobacterium spp. (isolate GT4), Staphylococcus xylosus (isolate BT5), Pantoea eucalypti (isolate NT6), Bacillus methylotrophicus (isolate MT3), Pseudomonas veronii (isolates BT4 and NT2), Pseudomonas rhodesiae (isolate BT2) and Pseudomonas cichorii (isolate NT3). After seed inoculation, BT2, BT4, MT3, MT8, NT2 and NT6 were re-isolated from leaf extracts. NT2, BT2, MT3 and NT6 inhibited growth of Botrytis cinerea and Pseudomonas syringae pv. tomato in vitro, produced antimicrobial compounds and reduced leaf damage caused by B. cinerea. Some of these isolates also promoted growth of tomato plants, produced siderophores, the auxin indole-3-acetic and solubilized inorganic phosphate. Thus, bacterial communities of leaves from field-grown tomato plants were found to harbor potentially endophytic culturable beneficial bacteria capable of antagonizing pathogenic microorganisms and promoting plant growth, which could be used as biological control agents and biofertilizers/biostimulators for promotion of tomato plant growth.

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

    PubMed

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

    1997-03-01

    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.

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

    NASA Technical Reports Server (NTRS)

    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.

  13. Modifications of Morphometrical and Physiological Parameters of Pepper Plants Grown on Artificial Nutrient Medium for Experiments in Spaceflight

    NASA Astrophysics Data System (ADS)

    Nechitailo, Galina S.

    2016-07-01

    MODIFICATIONS OF MORPHOMETRICAL AND PHYSIOLOGICAL PARAMETERS OF PEPPER PLANTS GROWN ON ARTIFICIAL NUTRIENT MEDIUM FOR EXPERIMENTS IN SPACEFLIGHT Lui Min*, Zhao Hui*, Chen Yu*, Lu Jinying*, Li Huasheng*, Sun Qiao*, Nechitajlo G.S.**, Glushchenko N.N.*** *Shenzhou Space Biotechnology Group, China Academy of Space Technology (CAST), **Emanuel Institute of Biochemical Physics of Russian Academy of Sciences (IBCP RAS) mail: spacemal@mail.ru ***V.L. Talrose Institute for Energy Problems of Chemical Physics of Russian Academy of Science (INEPCP RAS) mail: nnglu@ mail.ru In circumstances of space flights, long residence of the staff at space stations and space settlements an optimal engineering system of the life-support allowing to solve a number of technical and psychological problems for successful work and a life of cosmonauts, researchers, etc. is important and prime. In this respect it is necessary to consider growing plants on board of spacecraft as one of the units in a life-support system. It is feasible due to modern development of biotechnologies in growing plants allowing us to receive materials with new improved properties. Thus, a composition and ratio of components of nutrient medium can considerably influence on plants properties. We have developed the nutrient medium in which essential metals such as iron, zinc, copper were added in an electroneutral state in the form of nanoparticles instead of sulfates or other salts of the same metals. Such replacement is appropriate through unique nanoparticles properties: metal nanoparticles are less toxic than their corresponding ionic forms; nanoparticles produce a prolonged effect, serving as a depot for elements in an organism; nanoparticles introduced in biotic doses stimulate the metabolic processes of the organism; nanoparticles effect is multifunctional. Pepper strain LJ-king was used for growing on a nutrient medium with ferrous, zinc, copper nanoparticles in different concentrations. Pepper plants grown on

  14. Ensiling Characteristics of Alfalfa Leaves and Stems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The separate harvesting of alfalfa leaves and stems would provide farmers more flexibility in the harvesting and utilization of alfalfa, but a key issue is storage. In three trials, unwilted alfalfa leaves were ensiled alone or with cell wall degrading enzymes, formic acid or lactic acid bacterial i...

  15. Managing the rotation from alfalfa to corn

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alfalfa provides many benefits to cropping systems. These benefits occur both during alfalfa production and during the subsequent crops that follow. Some of the common benefits during alfalfa production are increased soil organic matter, decreased soil erosion, and decreased soil nitrate leaching lo...

  16. Efficiency of Nitrogen Assimilation by N2-Fixing and Nitrate-Grown Soybean Plants (Glycine max [L.] Merr.)

    PubMed Central

    Finke, Robert L.; Harper, James E.; Hageman, Richard H.

    1982-01-01

    Nodulated and non-nodulated (not inoculated) soybeans (Glycine max [L.] Merr. cv Wells) were grown in controlled environments with N2 or nonlimiting levels of NO3−, respectively, serving as sole source of nitrogen. The efficiency of the N2-fixing plants was compared with that of the nitrate-supplied plants on the basis of both plant age and plant size. Efficiency evaluations of the plants were expressed as the ratio of moles of carbon respired by the whole plant to the moles of nitrogen incorporated into plant material. Continuous 24-hour CO2 exchange measurements on shoot and root systems made at the beginning of flowering (28 days after planting) indicated that N2-fixing plants respired 8.28 moles of carbon per mole of N, fixed from dinitrogen, while nitrate-supplied plants respired only 4.99 moles of carbon per mole of nitrate reduced. Twenty-one-day-old nitrate-supplied plants were even more efficient, respiring only 3.18 moles of carbon per mole of nitrate reduced. The decreased efficiency of the N2-fixing plants was not due to plant size since, on a dry weight basis, the 28-day-old N2-fixing plants were intermediate between the 28- and 21-day-old nitrate-supplied plants. The calculated efficiencies were predominantly a reflection of root-system respiration. N2-fixing plants lost 25% of their daily net photosynthetic input of carbon through root-system respiration, compared with 16% for 28-day-old nitrate-supplied plants and 12% for 21-day-old nitrate-supplied plants. Shoot dark respiration was similar for all three plant groups, varying between 7.9% and 9.0% of the apparent photosynthate. The increased respiratory loss by the roots of the N2-fixing plants was not compensated for by increased net photosynthetic effectiveness. Canopy photosynthesis expressed on a leaf area basis was similar for 28-day-old N2-fixing plants (15.5 milligrams CO2 square decimeter per hour) and 21-day-old nitrate-supplied plants (14.5 milligrams CO2 square decimeter per hour

  17. Perfluoroalkyl acid distribution in various plant compartments of edible crops grown in biosolids-amended soils

    EPA Science Inventory

    Crop uptake of perfluoroalkyl acids (PFAAs) from biosolids-amended soil has been identified as a potential pathway for PFAA entry into the terrestrial food chain. This study compared the uptake of PFAAs in greenhouse-grown radish (Raphanus sativus), celery (Apium graveolens var.d...

  18. Expression of β-Amylase from Alfalfa Taproots1

    PubMed Central

    Gana, Joyce A.; Kalengamaliro, Newton E.; Cunningham, Suzanne M.; Volenec, Jeffrey J.

    1998-01-01

    Alfalfa (Medicago sativa L.) roots contain large quantities of β-amylase, but little is known about its role in vivo. We studied this by isolating a β-amylase cDNA and by examining signals that affect its expression. The β-amylase cDNA encoded a 55.95-kD polypeptide with a deduced amino acid sequence showing high similarity to other plant β-amylases. Starch concentrations, β-amylase activities, and β-amylase mRNA levels were measured in roots of alfalfa after defoliation, in suspension-cultured cells incubated in sucrose-rich or -deprived media, and in roots of cold-acclimated germ plasms. Starch levels, β-amylase activities, and β-amylase transcripts were reduced significantly in roots of defoliated plants and in sucrose-deprived cell cultures. β-Amylase transcript was high in roots of intact plants but could not be detected 2 to 8 d after defoliation. β-Amylase transcript levels increased in roots between September and October and then declined 10-fold in November and December after shoots were killed by frost. Alfalfa roots contain greater β-amylase transcript levels compared with roots of sweetclover (Melilotus officinalis L.), red clover (Trifolium pratense L.), and birdsfoot trefoil (Lotus corniculatus L.). Southern analysis indicated that β-amylase is present as a multigene family in alfalfa. Our results show no clear association between β-amylase activity or transcript abundance and starch hydrolysis in alfalfa roots. The great abundance of β-amylase and its unexpected patterns of gene expression and protein accumulation support our current belief that this protein serves a storage function in roots of this perennial species. PMID:9847126

  19. Salicornia strobilacea (Synonym of Halocnemum strobilaceum) Grown under Different Tidal Regimes Selects Rhizosphere Bacteria Capable of Promoting Plant Growth

    PubMed Central

    Marasco, Ramona; Mapelli, Francesca; Rolli, Eleonora; Mosqueira, Maria J.; Fusi, Marco; Bariselli, Paola; Reddy, Muppala; Cherif, Ameur; Tsiamis, George; Borin, Sara; Daffonchio, Daniele

    2016-01-01

    Halophytes classified under the common name of salicornia colonize salty and coastal environments across tidal inundation gradients. To unravel the role of tide-related regimes on the structure and functionality of root associated bacteria, the rhizospheric soil of Salicornia strobilacea (synonym of Halocnemum strobilaceum) plants was studied in a tidal zone of the coastline of Southern Tunisia. Although total counts of cultivable bacteria did not change in the rhizosphere of plants grown along a tidal gradient, significant differences were observed in the diversity of both the cultivable and uncultivable bacterial communities. This observation indicates that the tidal regime is contributing to the bacterial species selection in the rhizosphere. Despite the observed diversity in the bacterial community structure, the plant growth promoting (PGP) potential of cultivable rhizospheric bacteria, assessed through in vitro and in vivo tests, was equally distributed along the tidal gradient. Root colonization tests with selected strains proved that halophyte rhizospheric bacteria (i) stably colonize S. strobilacea rhizoplane and the plant shoot suggesting that they move from the root to the shoot and (ii) are capable of improving plant growth. The versatility in the root colonization, the overall PGP traits and the in vivo plant growth promotion under saline condition suggest that such beneficial activities likely take place naturally under a range of tidal regimes. PMID:27597846

  20. From fresh vegetables to the harvest of wheat plants grown in the "SVET" space greenhouse onboard the MIR orbital station

    NASA Technical Reports Server (NTRS)

    Ivanova, T.; Kostov, P.; Sapunova, S.; Dandolov, I.; Sytchev, V.; Podolski, I.; Levinskikh, M.; Meleshko, G.; Bingham, G.; Salisbury, F.

    1997-01-01

    Researchers report the results of experiments conducted onboard MIR in 1990, 1995, and 1996 in raising edible crops. In the 1990 experiment, radishes and Chinese cabbage were grown successfully, though the experimental plants were up to four times smaller than controls at harvest. The 1995 experiment in growing wheat through a complete life cycle was not completed. The 1996 experiment was successful in growing wheat through a complete life cycle to the seed stage. No seeds developed on any of the 279 ears harvested in that experiment. Reasons for the seedless development are explored.

  1. Effects of phosphate and thiosulphate on arsenic accumulation in Brassica juncea plants grown in soil and in hydroponic culture

    NASA Astrophysics Data System (ADS)

    Pezzarossa, Beatrice; Petruzzelli, Gianniantonio; Grifoni, Martina; Rosellini, Irene; Malagoli, Mario; Schiavon, Michela

    2013-04-01

    Arsenic is recognised as a toxic metalloid and a strong pollutant in soils of many countries. Thus, the reclamation of contaminated areas is fundamental in order to protect both human health and agricultural production. This study is focused on the assisted phytoextraction, a technology for reclaiming polluted soils that takes advantage of the capability of some plants to extract inorganic elements from soils with the aid of additive agents. The nutrients phosphorus, as phosphate, and sulphur, as thiosulphate, can compete with the form more oxidised of arsenic, both in soil and plant. This study examined the capability of thiosulphate (Th) and phosphate (Ph) to promote the release of As from soil surfaces in order to improve the phytoavailability and thus the absorption of As by Brassica juncea plants. In the first experiment B. juncea plants were grown on a soil that had been sampled from an industrial area strongly contaminated by As (790 mg As kg-1 soil). The second experiment was carried out in hydroponics where As has been added at a concentration (100 microM) similar to the As available concentration measured in soil. In both trials ammonium thiosulphate (at the concentration of 0.27 M in soil, and 400 microM in hydroponics) and potassium hydrogen phosphate (at the concentration of 0.05 M in soil, and 112 microM in hydroponics) were added. The biomass of B. juncea was determined and the accumulation of P, S and As in root and in the above-ground tissues have been analyzed. Our results showed that thiosulphate and phosphate acted either as nutrients and detoxifying agents, due to the stimulation of plant defensive systems, and influenced either the biomass production and the As accumulation in plant tissues. In the plants grown in soil, As accumulated at higher levels in the above-ground part than in the roots and the addition of Th induced a higher biomass production and a higher total As accumulation (concentration x biomass) in the above-ground tissues

  2. Phenology and abundance of bean leaf beetle (Coleoptera: Chrysomelidae) in eastern South Dakota on alfalfa and soybean relative to tillage, fertilization, and yield.

    PubMed

    Hammack, Leslie; Pikul, Joseph L; West, Mark S

    2010-06-01

    Phenology and abundance of bean leaf beetles, Cerotoma trifurcata (Förster), were examined throughout two eastern South Dakota growing seasons in relation to grain yields in chisel- and ridge-tilled soybeans [Glycine max (L.) Merrill] grown in 2-yr rotation with corn (Zea mays L.) with and without added nitrogen (N). Populations were also sampled early and late season in alfalfa (Medicago sativa L.). Beetles were present in alfalfa by late May and most were reproductively active within a week, but their presence in alfalfa did not always precede soybean emergence. Most beetles taken from alfalfa in late fall were teneral; all were previtellogenic and unmated. Reproductively active beetles were detected in soybeans as soon as seedlings emerged. A partial second generation apparently occurred each year. First-generation beetles started to emerge in soybean fields during the first or third week of July but, whether emergence started early or late, most beetles emerging after July seemingly failed to mature their eggs and started leaving soybeans within several weeks of eclosion. This pattern suggested that any second generation arose from only the earliest emerging beetles of the first generation, with later emerging individuals having to overwinter before reproducing. Thus, any factors delaying emergence of the first generation, such as delayed soybean planting, could potentially limit its reproductive capacity through winter mortality. Cumulative seasonal beetle counts were lower in N-treated subplots and in ridge-tilled compared with chisel-tilled plots. Soybean grain yield increased with decreases in peak abundance of first-generation beetles and with N fertilization.

  3. Role of Silicon Counteracting Cadmium Toxicity in Alfalfa (Medicago sativa L.)

    PubMed Central

    Kabir, Ahmad H.; Hossain, Mohammad M.; Khatun, Most A.; Mandal, Abul; Haider, Syed A.

    2016-01-01

    Cadmium (Cd) is one of the most phytotoxic elements causing an agricultural problem and human health hazards. This work investigates whether and how silicon (Si) ameliorates Cd toxicity in Alfalfa. The addition of Si in Cd-stressed plants caused significant improvement in morpho-physiological features as well as total protein and membrane stability, indicating that Si does have critical roles in Cd detoxification in Alfalfa. Furthermore, Si supplementation in Cd-stressed plants showed a significant decrease in Cd and Fe concentrations in both roots and shoots compared with Cd-stressed plants, revealing that Si-mediated tolerance to Cd stress is associated with Cd inhibition in Alfalfa. Results also showed no significant changes in the expression of two metal chelators [MsPCS1 (phytochelatin synthase) and MsMT2 (metallothionein)] and PC (phytochelatin) accumulation, indicating that there may be no metal sequestration or change in metal sequestration following Si application under Cd stress in Alfalfa. We further performed a targeted study on the effect of Si on Fe uptake mechanisms. We observed the consistent reduction in Fe reductase activity, expression of Fe-related genes [MsIRT1 (Fe transporter), MsNramp1 (metal transporter) and OsFRO1 (ferric chelate reductase] and Fe chelators (citrate and malate) by Si application to Cd stress in roots of Alfalfa. These results support that limiting Fe uptake through the down-regulation of Fe acquisition mechanisms confers Si-mediated alleviation of Cd toxicity in Alfalfa. Finally, an increase of catalase, ascorbate peroxidase, and superoxide dismutase activities along with elevated methionine and proline subjected to Si application might play roles, at least in part, to reduce H2O2 and to provide antioxidant defense against Cd stress in Alfalfa. The study shows evidence of the effect of Si on alleviating Cd toxicity in Alfalfa and can be further extended for phytoremediation of Cd toxicity in plants. PMID:27512401

  4. Role of Silicon Counteracting Cadmium Toxicity in Alfalfa (Medicago sativa L.).

    PubMed

    Kabir, Ahmad H; Hossain, Mohammad M; Khatun, Most A; Mandal, Abul; Haider, Syed A

    2016-01-01

    Cadmium (Cd) is one of the most phytotoxic elements causing an agricultural problem and human health hazards. This work investigates whether and how silicon (Si) ameliorates Cd toxicity in Alfalfa. The addition of Si in Cd-stressed plants caused significant improvement in morpho-physiological features as well as total protein and membrane stability, indicating that Si does have critical roles in Cd detoxification in Alfalfa. Furthermore, Si supplementation in Cd-stressed plants showed a significant decrease in Cd and Fe concentrations in both roots and shoots compared with Cd-stressed plants, revealing that Si-mediated tolerance to Cd stress is associated with Cd inhibition in Alfalfa. Results also showed no significant changes in the expression of two metal chelators [MsPCS1 (phytochelatin synthase) and MsMT2 (metallothionein)] and PC (phytochelatin) accumulation, indicating that there may be no metal sequestration or change in metal sequestration following Si application under Cd stress in Alfalfa. We further performed a targeted study on the effect of Si on Fe uptake mechanisms. We observed the consistent reduction in Fe reductase activity, expression of Fe-related genes [MsIRT1 (Fe transporter), MsNramp1 (metal transporter) and OsFRO1 (ferric chelate reductase] and Fe chelators (citrate and malate) by Si application to Cd stress in roots of Alfalfa. These results support that limiting Fe uptake through the down-regulation of Fe acquisition mechanisms confers Si-mediated alleviation of Cd toxicity in Alfalfa. Finally, an increase of catalase, ascorbate peroxidase, and superoxide dismutase activities along with elevated methionine and proline subjected to Si application might play roles, at least in part, to reduce H2O2 and to provide antioxidant defense against Cd stress in Alfalfa. The study shows evidence of the effect of Si on alleviating Cd toxicity in Alfalfa and can be further extended for phytoremediation of Cd toxicity in plants.

  5. Mercury uptake and phytotoxicity in terrestrial plants grown naturally in the Gumuskoy (Kutahya) mining area, Turkey.

    PubMed

    Sasmaz, Merve; Akgül, Bunyamin; Yıldırım, Derya; Sasmaz, Ahmet

    2016-01-01

    This study investigated mercury (Hg) uptake and transport from the soil to different plant parts by documenting the distribution and accumulation of Hg in the roots and shoots of 12 terrestrial plant species, all of which grow naturally in surface soils of the Gumuskoy Pb-Ag mining area. Plant samples and their associated soils were collected and analyzed for Hg content by ICP-MS. Mean Hg values in the soils, roots, and shoots of all plants were 6.914, 460, and 206 µg kg(-1), respectively and lower than 1. The mean enrichment factors for the roots (ECR) and shoots (ECS) of these plants were 0.06 and 0.09, respectively and lower than 1. These results show that the roots of the studied plants prevented Hg from reaching the aerial parts of the plants. The mean translocation factor (TLF) was 1.29 and higher than 1. The mean TLF values indicated that all 12 plant species had the ability to transfer Hg from the roots to the shoots but that transfer was more efficient in plants with higher ECR and ECS. Therefore, these plants could be useful for the biomonitoring of environmental pollution and for rehabilitating areas contaminated by Hg.

  6. A meta-analysis of arbuscular mycorrhizal effects on plants grown under salt stress.

    PubMed

    Chandrasekaran, Murugesan; Boughattas, Sonia; Hu, Shuijin; Oh, Sang-Hyon; Sa, Tongmin

    2014-11-01

    Salt stress limits crop yield and sustainable agriculture in most arid and semiarid regions of the world. Arbuscular mycorrhizal fungi (AMF) are considered bio-ameliorators of soil salinity tolerance in plants. In evaluating AMF as significant predictors of mycorrhizal ecology, precise quantifiable changes in plant biomass and nutrient uptake under salt stress are crucial factors. Therefore, the objective of the present study was to analyze the magnitude of the effects of AMF inoculation on growth and nutrient uptake of plants under salt stress through meta-analyses. For this, data were compared in the context of mycorrhizal host plant species, plant family and functional group, herbaceous vs. woody plants, annual vs. perennial plants, and the level of salinity across 43 studies. Results indicate that, under saline conditions, AMF inoculation significantly increased total, shoot, and root biomass as well as phosphorous (P), nitrogen (N), and potassium (K) uptake. Activities of the antioxidant enzymes superoxide dismutase, catalase, peroxidase, and ascorbate peroxidase also increased significantly in mycorrhizal compared to nonmycorrhizal plants growing under salt stress. In addition, sodium (Na) uptake decreased significantly in mycorrhizal plants, while changes in proline accumulation were not significant. Across most subsets of the data analysis, identities of AMF (Glomus fasciculatum) and host plants (Acacia nilotica, herbs, woody and perennial) were found to be essential in understanding plant responses to salinity stress. For the analyzed dataset, it is concluded that under salt stress, mycorrhizal plants have extensive root traits and mycorrhizal morphological traits which help the uptake of more P and K, together with the enhanced production of antioxidant enzymes resulting in salt stress alleviation and increased plant biomass.

  7. Evaluation of holocellulase production by plant-degrading fungi grown on agro-industrial residues.

    PubMed

    de Siqueira, Félix Gonçalves; de Siqueira, Aline Gonçalves; de Siqueira, Eliane Gonçalves; Carvalho, Marly Azevedo; Peretti, Beatriz Magalhães Pinto; Jaramillo, Paula Marcela Duque; Teixeira, Ricardo Sposina Sobral; Dias, Eustáquio Souza; Félix, Carlos Roberto; Filho, Edivaldo Ximenes Ferreira

    2010-09-01

    Agaricus brasiliensis CS1, Pleurotus ostreatus H1 and Aspergillus flavus produced holocellulases when grown in solid and submerged liquid cultures containing agro-industrial residues, including sugar cane bagasse and dirty cotton residue, as substrates. These isolates proved to be efficient producers of holocellulases under the conditions used in this screening. Bromatological analysis of agro-industrial residues showed differences in protein, fiber, hemicellulose, cellulose and lignin content. Maximal holocellulase activity (hemicellulase, cellulase and pectinase) was obtained using solid-state cultivation with 10% substrate concentration. In this case, remarkably high levels of xylanase and polygalacturonase activity (4,008 and 4,548 IU/l, respectively) were produced by A. flavus when grown in media containing corn residue, followed by P. ostreatus H1 with IU/l values of 1,900 and 3,965 when cultivated on 5% and 10% sugar cane bagasse, respectively. A. brasiliensis CS1 showed the highest reducing sugar yield (11.640 mg/ml) when grown on medium containing sugar cane bagasse. A. brasiliensis was also the most efficient producer of protein, except when cultivated on dirty cotton residue, which induced maximal production in A. flavus. Comparison of enzymatic hydrolysis of sugar cane bagasse and dirty cotton residue by crude extracts of A. brasiliensis CS1, P. ostreatus H1 and A. flavus showed that the best reducing sugar yield was achieved using sugar cane bagasse as a substrate.

  8. Response of Two Plant Species to Two Ultraviolet-B Radiation Regimes

    NASA Technical Reports Server (NTRS)

    Levy, Daniel L.; Skiles, J. W.; Peterson, David (Technical Monitor)

    1996-01-01

    The depleted stratospheric ozone layer has been directly linked to increased levels of ultraviolet radiation at the earth's surface. It is important to understand what effect this will have on plants. We tested the hypothesis that in response to increased UV-B radiation (280-320 man), soybean (Glycine max Merrill) and alfalfa (Mercado Saliva L.) would produce higher concentrations of flavonoids than plants screened from UV-B. Soybean and alfalfa plants were grown successively in a growth chamber that provided UV-B radiation intensities 45% above summer field levels. A wooden frame was used to suspend mylar-D film over one group of plants and mono-acetate film over another group. Mylar is opaque in the 280-316 nm range, and acetate absorbs most radiation from 280-290 nm and then reduces intensities in the 290-320 nm range by roughly 15%. Leaf chlorophyll concentration was determined with a Minolta SPAD-502 chlorophyll meter; the BRAD meter was calibrated with N,N- extractions. Flavonoids were extracted with an acidified methanol/water solution. Soybean grown under the acetate treatment showed 26% smaller internodal lengths and higher concentrations of flavonoids compared to plants grown under mylar. Significant results for alfalfa included 22% greater leaf flavonoid concentration under acetate, 14% greater leaf chlorophyll concentration under mylar, and 32% greater above-ground biomass under mylar. We found that increased UV-B radiation leads to increased production of UV-B absorbing compounds (i.e. flavonoids) in soybean and alfalfa leaves. This suggests that a protective mechanism in these plants is triggered by UV-B. In response, flavonoids are produced that absorb UV-B, and consequently decrease potentially damaging effects to the plants. In addition, we hypothesize that this flavonoid protection mechanism saturates at certain UV-B intensities.

  9. Two Bee-Pollinated Plant Species Show Higher Seed Production when Grown in Gardens Compared to Arable Farmland

    PubMed Central

    Cussans, John; Goulson, David; Sanderson, Roy; Goffe, Louis; Darvill, Ben; Osborne, Juliet L.

    2010-01-01

    Background Insect pollinator abundance, in particular that of bees, has been shown to be high where there is a super-abundance of floral resources; for example in association with mass-flowering crops and also in gardens where flowering plants are often densely planted. Since land management affects pollinator numbers, it is also likely to affect the resultant pollination of plants growing in these habitats. We hypothesised that the seed or fruit set of two plant species, typically pollinated by bumblebees and/or honeybees might respond in one of two ways: 1) pollination success could be reduced when growing in a floriferous environment, via competition for pollinators, or 2) pollination success could be enhanced because of increased pollinator abundance in the vicinity. Methodology/Principal Findings We compared the pollination success of experimental plants of Glechoma hederacea L. and Lotus corniculatus L. growing in gardens and arable farmland. On the farms, the plants were placed either next to a mass-flowering crop (oilseed rape, Brassica napus L. or field beans, Vicia faba L.) or next to a cereal crop (wheat, Triticum spp.). Seed set of G. hederacea and fruit set of L. corniculatus were significantly higher in gardens compared to arable farmland. There was no significant difference in pollination success of G. hederacea when grown next to different crops, but for L. corniculatus, fruit set was higher in the plants growing next to oilseed rape when the crop was in flower. Conclusions/Significance The results show that pollination services can limit fruit set of wild plants in arable farmland, but there is some evidence that the presence of a flowering crop can facilitate their pollination (depending on species and season). We have also demonstrated that gardens are not only beneficial to pollinators, but also to the process of pollination. PMID:20668704

  10. Scale-up of Agrobacterium-mediated transient protein expression in bioreactor-grown Nicotiana glutinosa plant cell suspension culture.

    PubMed

    O'Neill, Kristin M; Larsen, Jeffrey S; Curtis, Wayne R

    2008-01-01

    The reporter gene beta-glucuronidase was transiently expressed in a 51-L bioreactor-grown plant cell suspension culture of Nicotiana glutinosa at a yield of approximately 1.1 mg through co-culture with an auxotrophic strain of Agrobacterium tumefaciens. The three order of magnitude scale-up involved the investigation of factors contributing to transient expression including the timing of Agrobacterium inoculation relative to the plant cell growth phase, plant tissue culture hormonal triggers and plant cell cycle synchronization. The co-culture process was simplified to facilitate implementation in a pilot-scale bioreactor. At the shake flask scale it was determined that elevated concentrations of oxygen in the headspace were detrimental to transient expression levels and the addition of acetosyringone to the co-culture had a negligible effect. The bacterial preparation process was also streamlined, permitting the direct transfer of the Agrobacterium culture from a bench-scale fermentor to the pilot-scale plant cell culture bioreactor. Increasing expression levels and overcoming batch-to-batch variability despite extensive procedure systemization remain the major technical hurdles.

  11. Effect of silicon addition on soybean (Glycine max) and cucumber (Cucumis sativus) plants grown under iron deficiency.

    PubMed

    Gonzalo, María José; Lucena, Juan J; Hernández-Apaolaza, Lourdes

    2013-09-01

    Silicon is considered an essential element in several crops enhancing growth and alleviating different biotic and abiotic stresses. In this work, the role of Si in the alleviation of iron deficiency symptoms and in the Fe distribution in iron deficient plants has been studied. Thus, soybean and cucumber plants grown in hydroponic culture under iron limiting conditions were treated with different Si doses (0.0, 0.5 and 1.0 mM). The use of a strong chelating agent such as HBED avoided Fe co-precipitation in the nutrient solution and allowed for the first time the analysis of Si effect in iron nutrition without the interference of the iron rhizospheric precipitation. SPAD index, plant growth parameters and mineral content in plant organs were determined. For soybean, the addition of 0.5 mM of Si to the nutrient solution without iron, initially or continuously during the experiment, prevented the chlorophyll degradation, slowed down the growth decrease due to the iron deficiency and maintained the Fe content in leaves. In cucumber, Si addition delayed the decrease of stem dry weight, stem length, node number and iron content in stems and roots independently of the dose, but no-effect was observed in chlorosis symptoms alleviation in leaves. The observed response to Si addition in iron deficiency was plant-specific, probably related with the different Fe efficiency strategies developed by these two species.

  12. Interactive effects of temperature and UVB radiation on methane emissions from different organs of pea plants grown in hydroponic system.

    PubMed

    Abdulmajeed, Awatif M; Derby, Samantha R; Strickland, Samantha K; Qaderi, Mirwais M

    2017-01-01

    There is no information on variation of methane (CH4) emissions from plant organs exposed to multiple environmental factors. We investigated the interactive effects of temperature and ultraviolet-B (UVB) radiation on CH4 emissions from different organs of pea (Pisum sativum L. var. UT234 Lincoln). Plants were grown hydroponically under two temperatures (22/18°C and 28/24°C; 16h day/8h night) and two levels of UVB radiation [0 and 5kJm(-2) d(-1)] in controlled-environment growth chambers for ten days, after two weeks of initial growth under ambient temperatures. Methane emission, dry mass, growth index, electrical conductivity (EC), pectin, total chlorophyll content, gas exchange and flavonoids were measured in the appropriate plant organs - leaf, stem and root. Higher temperatures increased CH4 emissions, leaf mass ratio, and shoot: root mass ratio. Neither temperature nor UVB had significant effects on leaf, stem, root and total dry mass, EC, pectin, total chlorophyll, as well as specific leaf mass. Among plant organs, there were differences in CH4, EC, pectin and total chlorophyll. Methane and EC were highest for the stem and lowest for the leaf; leaf had highest, but stem had lowest, pectin content; total chlorophyll was highest in the leaf but lowest in the root. Higher temperatures decreased leaf flavonoids, net carbon dioxide assimilation, and water use efficiency. Overall, environmental stressors increased aerobic CH4 emission rates, which varied with plant organs.

  13. Effects of engineered Sinorhizobium meliloti on cytokinin synthesis and tolerance of alfalfa to extreme drought stress.

    PubMed

    Xu, Ji; Li, Xiao-Lin; Luo, Li

    2012-11-01

    Cytokinin is required for the initiation of leguminous nitrogen fixation nodules elicited by rhizobia and the delay of the leaf senescence induced by drought stress. A few free-living rhizobia have been found to produce cytokinin. However, the effects of engineered rhizobia capable of synthesizing cytokinin on host tolerance to abiotic stresses have not yet been described. In this study, two engineered Sinorhizobium strains overproducing cytokinin were constructed. The tolerance of inoculated alfalfa plants to severe drought stress was assessed. The engineered strains, which expressed the Agrobacterium ipt gene under the control of different promoters, synthesized more zeatins than the control strain under free-living conditions, but their own growth was not affected. After a 4-week inoculation period, the effects of engineered strains on alfalfa growth and nitrogen fixation were similar to those of the control strain under nondrought conditions. After being subjected to severe drought stress, most of the alfalfa plants inoculated with engineered strains survived, and the nitrogenase activity in their root nodules showed no apparent change. A small elevation in zeatin concentration was observed in the leaves of these plants. The expression of antioxidant enzymes increased, and the level of reactive oxygen species decreased correspondingly. Although the ipt gene was transcribed in the bacteroids of engineered strains, the level of cytokinin in alfalfa nodules was identical to that of the control. These findings suggest that engineered Sinorhizobium strains synthesizing more cytokinin could improve the tolerance of alfalfa to severe drought stress without affecting alfalfa nodulation or nitrogen fixation.

  14. Root morphology, hydraulic conductivity and plant water relations of high-yielding rice grown under aerobic conditions

    PubMed Central

    Kato, Yoichiro; Okami, Midori

    2011-01-01

    Background and Aims Increasing physical water scarcity is a major constraint for irrigated rice (Oryza sativa) production. ‘Aerobic rice culture’ aims to maximize yield per unit water input by growing plants in aerobic soil without flooding or puddling. The objective was to determine (a) the effect of water management on root morphology and hydraulic conductance, and (b) their roles in plant–water relationships and stomatal conductance in aerobic culture. Methods Root system development, stomatal conductance (gs) and leaf water potential (Ψleaf) were monitored in a high-yielding rice cultivar (‘Takanari’) under flooded and aerobic conditions at two soil moisture levels [nearly saturated (> –10 kPa) and mildly dry (> –30 kPa)] over 2 years. In an ancillary pot experiment, whole-plant hydraulic conductivity (soil-leaf hydraulic conductance; Kpa) was measured under flooded and aerobic conditions. Key Results Adventitious root emergence and lateral root proliferation were restricted even under nearly saturated conditions, resulting in a 72–85 % reduction in total root length under aerobic culture conditions. Because of their reduced rooting size, plants grown under aerobic conditions tended to have lower Kpa than plants grown under flooded conditions. Ψleaf was always significantly lower in aerobic culture than in flooded culture, while gs was unchanged when the soil moisture was at around field capacity. gs was inevitably reduced when the soil water potential at 20-cm depth reached –20 kPa. Conclusions Unstable performance of rice in water-saving cultivations is often associated with reduction in Ψleaf. Ψleaf may reduce even if Kpa is not significantly changed, but the lower Ψleaf would certainly occur in case Kpa reduces as a result of lower water-uptake capacity under aerobic conditions. Rice performance in aerobic culture might be improved through genetic manipulation that promotes lateral root branching and rhizogenesis as well as deep

  15. Variations in heavy metal accumulation, growth and yield of rice plants grown at different sewage sludge amendment rates.

    PubMed

    Singh, R P; Agrawal, M

    2010-05-01

    Use of sewage sludge in agriculture is an alternative disposal technique for this waste. The present field study was conducted to assess the suitability of sewage sludge amendment in soil for rice (Oryza sativa L. cv. Pusa sugandha 3) by evaluating the heavy metal accumulation, growth, biomass and yield responses of plants grown at 0, 3, 4.5, 6, 9, 12 kgm(-2) sewage sludge amendment (SSA) rate. Sewage sludge amendment modified the physico-chemical properties of soil, thus increasing the availability of heavy metals in soil and consequently with higher accumulation in plant parts. Root length decreased, whereas shoot length, number of leaves, leaf area and total biomass increased significantly when grown under various SSA rates. Yield of rice increased by 60%, 111%, 125%, 134% and 137% at 3, 4.5, 6, 9 and 12 kgm(-2) SSA, respectively, as compared to those grown in unamended soil. Sewage sludge amendment rates above 4.5 kgm(-2) though increased the yield of rice, but caused risk of food chain contamination as concentrations of Ni and Cd in rice grains were found to be above the Indian safe limits (1.5 mgkg(-1)) of human consumption above 4.5 kgm(-2) SSA and of Pb (2.5 mgkg(-1)) above 6 kgm(-2) SSA. Since aboveground parts of the rice also showed higher concentration than the permissible levels of Ni, Cd and Pb at 4.5 kgm(-2) SSA rate, it cannot be used as fodder. The rice husk may be used as bioresource for energy production. Efforts should be made to treat the effluents from small scale industries before discharge into the sewerage system.

  16. Metaproteomic identification of diazotrophic methanotrophs and their localization in root tissues of field-grown rice plants.

    PubMed

    Bao, Zhihua; Okubo, Takashi; Kubota, Kengo; Kasahara, Yasuhiro; Tsurumaru, Hirohito; Anda, Mizue; Ikeda, Seishi; Minamisawa, Kiwamu

    2014-08-01

    In a previous study by our group, CH4 oxidation and N2 fixation were simultaneously activated in the roots of wild-type rice plants in a paddy field with no N input; both processes are likely controlled by a rice gene for microbial symbiosis. The present study examined which microorganisms in rice roots were responsible for CH4 oxidation and N2 fixation under the field conditions. Metaproteomic analysis of root-associated bacteria from field-grown rice (Oryza sativa Nipponbare) revealed that nitrogenase complex-containing nitrogenase reductase (NifH) and the alpha subunit (NifD) and beta subunit (NifK) of dinitrogenase were mainly derived from type II methanotrophic bacteria of the family Methylocystaceae, including Methylosinus spp. Minor nitrogenase proteins such as Methylocella, Bradyrhizobium, Rhodopseudomonas, and Anaeromyxobacter were also detected. Methane monooxygenase proteins (PmoCBA and MmoXYZCBG) were detected in the same bacterial group of the Methylocystaceae. Because these results indicated that Methylocystaceae members mediate both CH4 oxidation and N2 fixation, we examined their localization in rice tissues by using catalyzed reporter deposition-fluorescence in situ hybridization (CARD-FISH). The methanotrophs were localized around the epidermal cells and vascular cylinder in the root tissues of the field-grown rice plants. Our metaproteomics and CARD-FISH results suggest that CH4 oxidation and N2 fixation are performed mainly by type II methanotrophs of the Methylocystaceae, including Methylosinus spp., inhabiting the vascular bundles and epidermal cells of rice roots.

  17. Plant response of onion cultivars developed from greenhouse-grown transplants to plant density and fertilizer rate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Onions (Allium cepa L.) can be established from seed or transplants. The latter planting material can be dormant or actively growing when transplanted to the field. Onion transplants can be produced in a greenhouse, but there are gaps in the knowledge of the cultural requirements for these plants ...

  18. Highly Diverse Endophytic and Soil Fusarium oxysporum Populations Associated with Field-Grown Tomato Plants

    PubMed Central

    Demers, Jill E.; Gugino, Beth K.

    2014-01-01

    The diversity and genetic differentiation of populations of Fusarium oxysporum associated with tomato fields, both endophytes obtained from tomato plants and isolates obtained from soil surrounding the sampled plants, were investigated. A total of 609 isolates of F. oxysporum were obtained, 295 isolates from a total of 32 asymptomatic tomato plants in two fields and 314 isolates from eight soil cores sampled from the area surrounding the plants. Included in this total were 112 isolates from the stems of all 32 plants, a niche that has not been previously included in F. oxysporum population genetics studies. Isolates were characterized using the DNA sequence of the translation elongation factor 1α gene. A diverse population of 26 sequence types was found, although two sequence types represented nearly two-thirds of the isolates studied. The sequence types were placed in different phylogenetic clades within F. oxysporum, and endophytic isolates were not monophyletic. Multiple sequence types were found in all plants, with an average of 4.2 per plant. The population compositions differed between the two fields but not between soil samples within each field. A certain degree of differentiation was observed between populations associated with different tomato cultivars, suggesting that the host genotype may affect the composition of plant-associated F. oxysporum populations. No clear patterns of genetic differentiation were observed between endophyte populations and soil populations, suggesting a lack of specialization of endophytic isolates. PMID:25304514

  19. First report of Alfalfa mosaic virus infecting basil (Ocimum basilicum L.) in California.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Basil (Ocimum basilicum L.) plants collected from a field in Imperial County, CA in May, 2011 were found to exhibit yellowing, chlorotic sectors and spots on leaves, resulting in plants being unmarketable. Total nucleic acid was extracted from plants and tested by RT-PCR for the presence of Alfalfa...

  20. Combined effects of CO2 enrichment, changes in diurnal light level and water stress on foliar metabolites of potato plants grown in naturally sunlit controlled environment chambers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Potato plants (Solanum tuberosum L. cv Kennebec) were grown in outdoor, naturally sunlit, soil-plant-atmosphere research (SPAR) chambers. Drought treatments were imposed at post-tuber initiation stage to assess water stress effects on leaf metabolites, and interactions with enriched CO2 concentrati...

  1. Contrasting Strategies of Alfalfa Stem Elongation in Response to Fall Dormancy in Early Growth Stage: The Tradeoff between Internode Length and Internode Number

    PubMed Central

    Wang, Zongli; Sun, Qizhong

    2015-01-01

    Fall dormancy (FD) in alfalfa (Medicago sativa L.) can be described using 11 FD ratings, is widely used as an important indicator of stress resistance, productive performance and spring growth. However, the contrasting growth strategies in internode length and internode number in alfalfa cultivars with different FD rating are poorly understood. Here, a growth chamber study was conducted to investigate the effect of FD on plant height, aboveground biomass, internode length, and internode number in alfalfa individuals in the early growth stages. In order to simulate the alfalfa growth environment in the early stage, 11 alfalfa cultivars with FD ratings from one to 11 were chosen and seeded at the greenhouse, and then were transplanted into an artificial growth chamber. The experimental design was a randomized complete block in a split-plot arrangement with three replicates. Plant height, above-ground biomass, internode length, and internode number were measured in early growth stage in all individuals. Our findings showed that plant height and the aboveground biomass of alfalfa did not significantly differ among 11 different FD rated cultivars. Also, internode length and internode number positively affected plant height and the aboveground biomass of alfalfa individuals and the average internode length significantly increased with increasing FD rating. However, internode number tended to sharply decline when the FD rating increased. Moreover, there were no correlations, slightly negative correlations, and strongly negative correlations between internode length and internode number in alfalfa individuals among the three scales, including within-FD ratings, within-FD categories and inter-FD ratings, respectively. Therefore, our results highlighted that contrasting growth strategies in stem elongation were adopted by alfalfa with different FD ratings in the early growth stage. Alfalfa cultivars with a high FD rating have longer internodes, whereas more dormant alfalfa

  2. Comparative Analysis Of 226Ra Soil-To-Plant Transfer In Cabbage Grown In Various Regions

    NASA Astrophysics Data System (ADS)

    Madruga, M. J.; Carvalho, F. P.; Silva, L.; Gouveia, J.

    2008-08-01

    The transfer of 226Ra from soil to cabbage was compared amongst regions, namely the surroundings of Urgeiriça uranium milling tailings (GE), regions with past uranium mining activities (GN1), and regions with no uranium mining activities and no uranium deposits (GN2). Results show a slight increase of the concentration ratio values at low radium concentration in soils. Statistical analysis of the mean 226Ra activity concentrations in soil and cabbage for the three regions was carried out. The comparison of 226Ra activity concentrations in soils indicated no difference (p>0.05), between GE and GN2 and significant differences (p<0.05) between GE and GN1 and between GN1 and GN2. Similar statistical results were obtained for 226Ra activity concentrations in cabbage from the same regions. It was concluded that radium Concentration Ratio (CR) for cabbage grown in the region of the main uranium milling site (GE) is of the same order of magnitude of CR in cabagge grown in background regions (GN2). However, 226Ra CR was higher in cabagge from the region with past uranium mining activities (GN1).

  3. Japanese flowering cherry tree as a woody plant candidate grown in space

    NASA Astrophysics Data System (ADS)

    Tomita-Yokotani, K.; Yoshida, S.; Hashimoto, H.; Nyunoya, H.; Funada, R.; Katayama, T.; Suzuki, T.; Honma, T.; Nagatomo, M.; Nakamura, T.

    We are proposing to raise woody plant in space for several applications Japanese flowering cherry tree is a candidate to do wood science in space Mechanism of sensing gravity and controlling shape of tree has been studied quite extensively Cherry mutants associated with gravity are telling responsible plant hormones and molecular machinery for plant adaptation against action of gravity Space experiment using our wood model contribute to understand molecular and cellular process of gravitropism in plant Tree is considered to be an important member in space agriculture to produce excess oxygen wooden materials for constructing living environment and provide biomass for cultivating mushrooms and insects Furthermore trees and their flowers improve quality of life under stressful environment in outer space

  4. Effect of artificial electric fields on plants grown under microgravity conditions

    NASA Astrophysics Data System (ADS)

    Nechitailo, G.; Gordeev, A.

    2001-01-01

    Ionic and structural hetorogeneity of cells, tissues, and organs of plants are associated with a spectrum of electric characteristics such as bioelectric potentials, electrical conductance, and bioelectric permeability. An important determinant for the plant function is electric properties of the cell membranes and organelles which maintain energy and substance exchange with the environment. Enzymes and other biologically active substances have a powerful charge at the molecular level. Finally, all molecules, including those of water, represent dipoles, and this determines their reactive capacity. A major determinant is the bioelectric polarity of a plant is genetically predetermined and cannot be modified. It is an intrinsic structural feature of the organism whose evolution advent was mediated by gravity. An illustrative presentation of polarity is the downward growth of the roots and upward growth of stems in the Earth's gravitation field. However, gravity is a critical, but not the sole determinant of the plant organism polarization. Potent polarizing effects are exerted by light, the electromagnetic field, moisture, and other factors. It is known that plant cultivation in an upturned position is associated with impairment of water and nutrient uptake, resulting in dyscoordination of physiological processes, growth and developmental retardation. These abnormalities were characteristic when early attempts were made to grow plants in weightlessness conditions.

  5. Effect of artificial electric fields on plants grown under microgravity conditions.

    PubMed

    Nechitailo, G; Gordeev, A

    2001-01-01

    Ionic and structural hetorogeneity of cells, tissues, and organs of plants are associated with a spectrum of electric characteristics such as bioelectric potentials, electrical conductance, and bioelectric permeability. An important determinant for the plant function is electric properties of the cell membranes and organelles which maintain energy and substance exchange with the environment. Enzymes and other biologically active substances have a powerful charge at the molecular level. Finally, all molecules, including those of water, represent dipoles, and this determines their reactive capacity. A major determinant is the bioelectric polarity of a plant is genetically predetermined and cannot be modified. It is an intrinsic structural feature of the organism whose evolution advent was mediated by gravity. An illustrative presentation of polarity is the downward growth of the roots and upward growth of stems in the Earth's gravitation field. However, gravity is a critical, but not the sole determinant of the plant organism polarization. Potent polarizing effects are exerted by light, the electromagnetic field, moisture, and other factors. It is known that plant cultivation in an upturned position is associated with impairment of water and nutrient uptake, resulting in dyscoordination of physiological processes, growth and developmental retardation. These abnormalities were characteristic when early attempts were made to grow plants in weightlessness conditions.

  6. Quantitation of pyrimidine dimers in DNA from UVB-irradiated alfalfa (@ L. ) seedlings

    SciTech Connect

    Quaite, F.E.; Sutherland, B.M.; Sutherland, J.C.

    1991-01-01

    Depletion of stratospheric ozone will increase the solar ultraviolet radiation in the range from 290-320 nm (UVB) that reaches the surface of the earth, placing an increased UV burden on exposed organisms. One consequence of increased UVB may be decreased productivity of crop plants. A principal lesion caused by UV in DNA is the cyclobutyl pyrimidine dimer. We have adapted a method for measuring these dimers in nanogram quantities of non-radioactive DNA for use in UV-irradiated plants. We find that biologically relevant doses of broad band UVB radiation induce easily detectable frequencies of pyrimidine dimers in the DNA of irradiated alfalfa sprout leaves and that the dose response for dimer formation is linear up to doses of at least 690 J/m{sup 2}. We also find easily measurable frequencies of dimers in the leaves of seedlings grown in glass filtered sunlight but not exposed to additional UVB, suggesting that significant number of dimers are formed in plants exposed to normal sunlight. 27 refs., 3 figs., 1 tab.

  7. [Pb, Zn accumulation and nutrient uptake of 15 plant species grown in abandoned mine tailings].

    PubMed

    Shi, Xiang; Chen, Yi-Tai; Wang, Shu-Feng; Li, Jiang-Chuan

    2012-06-01

    Vegetation restoration field test was carried out in the abandoned lead-zinc tailings for 3 years. The study showed that accumulation of lead (Pb), zinc (Zn) and nutrient uptake differed with plant species and organs, heavy metals, and planting time. Pb was mainly accumulated in tree roots, and its content distribution in tree organs was generally in the order of roots > leaves > stems. But Zn concentrations in leaves of several tree species were higher than those in roots and stems. Within the tested 15 species, Cercis Canadensis had the highest concentrations of Pb and Zn in roots (1 803 and 2120 mg x kg(-1), respectively). Rhus chinensis had the highest Pb concentration in stems and leaves (280 and 546 mg x kg(-1), respectively) and Zn concentration (1 507 mg x kg(-1)) in leaves. Zn concentration in stems and leaves of Salix matsudana (729 and 1 153 mg x kg(-1), respectively) were the highest. Among the tested 15 species, TF values for Pb of Liquidambar formosana, Medicago sativa, and for Zn of Salix matsudana, Rhus chinensis, Medicago sativa were higher than 1. BCF values for Pb were all lower than 0.17, while that for Zn were all lower than 0.44. The N contents in nitrogen-fixing plants, P contents in Rhus typhina and Ailanthus altissima, and K content in Nerium indicum were significantly higher than those in other plants. With the increase of planting time, concentrations of heavy metal in plant body increased significantly; however the inverse trend were observed in nutritional element content. The species have higher metal accumulation capacity, such as Rhus chinensis, Salix matsudana and those nitrogen-fixing plants have higher tolerance to metal contamination and nutrient deficiency, such as Amorpha fruticosa, Medicago sativa, Lespedeza cuneata, and Alnus cremastogyne, they were suitable as the phytostabilizers in abandoned mine tailings.

  8. An Insight into microRNA156 Role in Salinity Stress Responses of Alfalfa.

    PubMed

    Arshad, Muhammad; Gruber, Margaret Y; Wall, Ken; Hannoufa, Abdelali

    2017-01-01

    Salinity is one of the major abiotic stresses affecting alfalfa productivity. Developing salinity tolerant alfalfa genotypes could contribute to sustainable crop production. The functions of microRNA156 (miR156) have been investigated in several plant species, but so far, no studies have been published that explore the role of miR156 in alfalfa response to salinity stress. In this work, we studied the role of miR156 in modulating commercially important traits of alfalfa under salinity stress. Our results revealed that overexpression of miR156 increased biomass, number of branches and time to complete growth stages, while it reduced plant height under control and salinity stress conditions. We observed a miR156-related reduction in neutral detergent fiber under non-stress, and acid detergent fiber under mild salinity stress conditions. In addition, enhanced total Kjeldahl nitrogen content was recorded in miR156 overexpressing genotypes under severe salinity stress. Furthermore, alfalfa genotypes overexpressing miR156 exhibited an altered ion homeostasis under salinity conditions. Under severe salinity stress, miR156 downregulated SPL transcription factor family genes, modified expression of other important transcription factors, and downstream salt stress responsive genes. Taken together, our results reveal that miR156 plays a role in mediating physiological and transcriptional responses of alfalfa to salinity stress.

  9. An Insight into microRNA156 Role in Salinity Stress Responses of Alfalfa

    PubMed Central

    Arshad, Muhammad; Gruber, Margaret Y.; Wall, Ken; Hannoufa, Abdelali

    2017-01-01

    Salinity is one of the major abiotic stresses affecting alfalfa productivity. Developing salinity tolerant alfalfa genotypes could contribute to sustainable crop production. The functions of microRNA156 (miR156) have been investigated in several plant species, but so far, no studies have been published that explore the role of miR156 in alfalfa response to salinity stress. In this work, we studied the role of miR156 in modulating commercially important traits of alfalfa under salinity stress. Our results revealed that overexpression of miR156 increased biomass, number of branches and time to complete growth stages, while it reduced plant height under control and salinity stress conditions. We observed a miR156-related reduction in neutral detergent fiber under non-stress, and acid detergent fiber under mild salinity stress conditions. In addition, enhanced total Kjeldahl nitrogen content was recorded in miR156 overexpressing genotypes under severe salinity stress. Furthermore, alfalfa genotypes overexpressing miR156 exhibited an altered ion homeostasis under salinity conditions. Under severe salinity stress, miR156 downregulated SPL transcription factor family genes, modified expression of other important transcription factors, and downstream salt stress responsive genes. Taken together, our results reveal that miR156 plays a role in mediating physiological and transcriptional responses of alfalfa to salinity stress. PMID:28352280

  10. Dredging Operations Technical Support Program. Comparison of the Heavy-Metal Uptake of Cyperus esculentus and of Agronomic Plants Grown on Contaminated Dutch Sediments.

    DTIC Science & Technology

    1985-06-01

    under reduced (flooded) and oxidized (upland) disposal conditions was studied in the greenhouse. Heavy-metal uptake by lettuce, radish, spring wheat , and...planted in the sediments was grown to maximum vegetative growth (45 days). Seeds of lettuce, radish, spring wheat , and red fescue grass were planted...spring wheat for Ni. Both DTPA-extractable and total metal in the substrates were related to plant metal concentrations, but for Zn the best fit was

  11. Experimental study of hyperspectral responses of plants grown on mud pit soil

    NASA Astrophysics Data System (ADS)

    Credoz, Anthony; Hédacq, Rémy; Barreau, Christophe; Dubucq, Dominique

    2016-10-01

    On-shore, hyperspectral imagery is currently used to detect and measure remotely oil spill extension for environmental purpose and hydrocarbon seepage for petroleum exploration. In this study, variations of hyperspectral signatures of vegetal species have been analyzed at the laboratory scale to detect indirectly the potential impacts on the plants of crude oil seepage and spills in the soil. Experimental study has been performed under greenhouse to simulate the exposure of two species of plants to a co-contamination of hydrocarbons and heavy metals contained in sludge from mud pit. Maize and bramble have been selected for this study since they are cultivated and spontaneous species respectively located in the region of interest. Five levels of exposure were performed over a period of 100 days. Reflectance evolution of each plant was measured with a spectroradiometer from 350 nm to 2500 nm with a dedicated leaf clip. Net morphological impacts were observed for maize with a global reduction of plants and leaves sizes correlated to the level of cocontamination. Hyperspectral measurement on maize revealed a higher reflectance in the absorption wavelength of water at 1450 and 1900 nm due to contamination and water stress. Reflectance in the visible increased at 600 nm (red interval) for bramble plants exposed to co-contamination. Then, the level of reflectance in the NIR decreased between 700 and 800 nm (red-edge) and absorption of water also decreased at 1450 and 1900 nm as described previously for the maize.

  12. Accumulation of heavy metals and antioxidant responses in Vicia faba plants grown on monometallic contaminated soil.

    PubMed

    Nadgórska-Socha, Aleksandra; Kafel, Alina; Kandziora-Ciupa, Marta; Gospodarek, Janina; Zawisza-Raszka, Agnieszka

    2013-02-01

    The purpose of this study was to explore the effects of soil contamination by selected metals (cadmium, copper, nickel, lead or zinc) on the antioxidant response of Vicia faba plants. The levels of the antioxidants: glutathione, proline, non-protein thiols, as well as guaiacol peroxidase and catalase activities were measured in the upper parts of plants. Additionally, the potential bioavailability of metals in the soil and their concentrations in V. faba plants were compared. Treatment with metal caused the problem of an elevation in its bioavailability in soil and its concentration in leaves and stems. The most serious problems seemed to be metal elevations in soil, especially Zn and Ni as well as in the aerial parts of V. faba plants. The antioxidant responses appeared to be metal specific. The elevation of guaiacol peroxidase activity in leaves and stems as well as the proline in leaves was the only more general reaction to metal exposure. Upon analysis of the effects of soil metal contamination on V. faba plants, we recommend the use of some measurements such as guaiacol peroxidase activity and proline level as useful tools in biological monitoring.

  13. Microbiological Sampling Methods and Sanitation of Edible Plants Grown on ISS

    NASA Technical Reports Server (NTRS)

    Parrish, Charles H. II; Khodadad, Christina L.; Garland, Nathaniel T.; Larson, Brian D.; Hummreick, Mary E.

    2013-01-01

    Pathogenic microbes on the surfaces of salad crops and growth chambers pose a threat to the health of crew on International Space Station. For astronauts to safely consume spacegrown vegetables produced in NASA's new vegetable production unit, VEGGIE, three technical challenges must be overcome: real-time sampling, microbiological analysis, and sanitation. Raphanus sativus cultivar Cherry Bomb II and Latuca sativa cultivar Outredgeous, two saled crops to be grown in VEGGIE, were inoculated with Salmonella enterica serovar Typhimurium (S. Typhimurium), a bacterium known to cause food-borne illness Tape- and swab-based sampling techniques were optimized for use in microgravity and assessed for effectiveness in recovery of bacteria from crop surfaces: Rapid pathogen detection and molecular analyses were performed via quantitative real-time polymerase chain reactiop using LightCycler® 480 and RAZOR® EX, a scaled-down instrument that is undergoing evaluation and testing for future flight hardware. These methods were compared with conventional, culture-based methods for the recovery of S. Typhimurium colonies. A sterile wipe saturated with a citric acid-based, food-grade sanitizer was applied to two different surface materials used in VEGGIE flight hardware that had been contaminated with the bacterium Pseudomonas aeruginosa,. another known human pathogen. To sanitize surfaces, wipes were saturated with either the sanitizer or sterile deionized water and applied to each surface. Colony forming units of P. aeruginosa grown on tryptic soy agar plates were enumerated from surface samples after sanitization treatments. Depending on the VEGGIE hardware material, 2- to 4.5-log10 reductions in colony-forming units were observed after sanitization. The difference in recovery of S. Typhimurium between tape- and swab- based sampling techniques was insignificant. RAZOR® EX rapidly detected S. Typhimurium present in both raw culture and extracted DNA samples.

  14. Assessing disease stress and modeling yield losses in alfalfa

    NASA Astrophysics Data System (ADS)

    Guan, Jie

    weight, percentage reflectance (810 nm), and green leaf area index (GLAI). Percentage reflectance (810 nm) assessments had a stronger relationship with dry weight and green leaf area index than percentage defoliation assessments. Our research conclusively demonstrates that percentage reflectance measurements can be used to nondestructively assess green leaf area index which is a direct measure of plant health and an indirect measure of productivity. This research conclusively demonstrates that remote sensing is superior to visual assessment method to assess alfalfa stress and to model yield and GLAI in the alfalfa foliar disease pathosystem.

  15. Transcriptome profiling in Arabidopsis inflorescence stems grown under hypergravity in terms of cell walls and plant hormones

    NASA Astrophysics Data System (ADS)

    Tamaoki, D.; Karahara, I.; Nishiuchi, T.; De Oliveira, S.; Schreiber, L.; Wakasugi, T.; Yamada, K.; Yamaguchi, K.; Kamisaka, S.

    2009-07-01

    Land plants rely on lignified secondary cell walls in supporting their body weight on the Earth. Although gravity influences the formation of the secondary cell walls, the regulatory mechanism of their formation by gravity is not yet understood. We carried out a comprehensive analysis of gene expression in inflorescence stems of Arabidopsis thaliana L. using microarray (22 K) to identify genes whose expression is modulated under hypergravity condition (300 g). Total RNA was isolated from the basal region of inflorescence stems of plants grown for 24 h at 300 g or 1 g. Microarray analysis showed that hypergravity up-regulated the expression of 403 genes to more than 2-fold. Hypergravity up-regulated the genes responsible for the biosynthesis or modification of cell wall components such as lignin, xyloglucan, pectin and structural proteins. In addition, hypergravity altered the expression of genes related to the biosynthesis of plant hormones such as auxin and ethylene and that of genes encoding hormone-responsive proteins. Our transcriptome profiling indicates that hypergravity influences the formation of secondary cell walls by modulating the pattern of gene expression, and that auxin and/or ethylene play an important role in signaling hypergravity stimulus.

  16. Fall-grown oat forages: cultivars, planting dates, and expected yields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    For the dairy industry, the options for producing a late-summer emergency forage crop are limited, mostly because the growing season is relatively short. Recent work conducted at Prairie du Sac (WI) has demonstrated that some cereal grains (primarily oats) planted in early August will joint, elongat...

  17. Effect of Hypergravity on Localization Calcium Ions in Plant Cells Grown in Vivo and in Vitro

    NASA Astrophysics Data System (ADS)

    Nedukha, Olena

    Using plant callus tissues and Arabidopsis thaliana plants as model systems we have been investigated the effect of hypergravity on the localization and relative content of calcium ions in photosynthesizing cells. The tobacco callus cells in log stage of growth and mesophyll cells from developed A. thaliana leaves were used in the experiments. Plant samples were exposed to hypergravity at 6.5 g, 10g and 14 g for 15-60 min. After centrifugation, dye Fluo-4 was loaded in the control leaves and the centrifuged samples by the standard cytochemical method. Observation of calcium fluorescence was carried out with a laser confocal microscope LSM 5 Pascal at the excitation wave 488 nm (by the argon laser), at emission wavelength 516 nm. The data of the calcium ion distribution and quantification in cells were obtained using software "Pascal" (Carl Zeiss). The effect of hypergravity on redistribution of calcium ions in plant cells has been established. This effect is depended from exposure time and from the value of hypergravity. The cells cultivated in vitro is showed fast response to hypergravity influence. Plasmolysis cells and calcium domains formation have been observed in most of callus cells. This influence was like to that, which was wrote in Funaria hygrometrica protonema cells after 8.5 g influence (Sytnik et al., 1984). Leaf cells of A. thaliana were of less responsively to hypergravity than callus cells. Sytnik K, Kordyum E, Nedukha O. et al. 1984. Plant Cell Under Change of Geophysical Factors. Kiev: Naukova Dumka, 1-134 p.

  18. Phyto extraction and accumulation of mercury in selected plant species grown in soil contaminated with different mercury compounds

    SciTech Connect

    Su, Y.; Han, F.; Shiyab, S.; Monts, D.L.

    2007-07-01

    /kg). Consequently, this plant species may not be suitable for mercury phyto-remediation. Other plant species, such as Indian mustard (Brassica juncea), a well-studied metal accumulator, exhibited severe chlorosis symptoms during some experiments. Among all the plant species studied, Chinese brake fern (Pteris vittata) accumulated significant amount of mercury in both roots and shoots and hence may be considered as a potential candidate for mercury phyto-extraction. During one experiment, brake ferns accumulated 540 mg/kg and 1469 mg/kg in shoots after 18 days of growing in soils treated with 500 ppm and 1000 ppm HgCl{sub 2} powder, respectively; no visual stress symptoms were observed. We also studied mercury phyto-remediation using aged soils that contaminated HgS, HgCl{sub 2}, and Hg(NO{sub 3}){sub 2}. We have found that up to hundreds of ppm mercury can be accumulated in the roots of Indian mustard plants grown with soil contaminated by mercury sulfide; HgS is assumed to be the most stable and also the predominant mercury form in Oak Ridge flood plain soils. We have also started to investigate different mercury uptake mechanisms, such as root uptake of soil contaminant and foliar mercury accumulation from ambient air. (authors)

  19. Metaproteomic Identification of Diazotrophic Methanotrophs and Their Localization in Root Tissues of Field-Grown Rice Plants

    PubMed Central

    Bao, Zhihua; Okubo, Takashi; Kubota, Kengo; Kasahara, Yasuhiro; Tsurumaru, Hirohito; Anda, Mizue; Ikeda, Seishi

    2014-01-01

    In a previous study by our group, CH4 oxidation and N2 fixation were simultaneously activated in the roots of wild-type rice plants in a paddy field with no N input; both processes are likely controlled by a rice gene for microbial symbiosis. The present study examined which microorganisms in rice roots were responsible for CH4 oxidation and N2 fixation under the field conditions. Metaproteomic analysis of root-associated bacteria from field-grown rice (Oryza sativa Nipponbare) revealed that nitrogenase complex-containing nitrogenase reductase (NifH) and the alpha subunit (NifD) and beta subunit (NifK) of dinitrogenase were mainly derived from type II methanotrophic bacteria of the family Methylocystaceae, including Methylosinus spp. Minor nitrogenase proteins such as Methylocella, Bradyrhizobium, Rhodopseudomonas, and Anaeromyxobacter were also detected. Methane monooxygenase proteins (PmoCBA and MmoXYZCBG) were detected in the same bacterial group of the Methylocystaceae. Because these results indicated that Methylocystaceae members mediate both CH4 oxidation and N2 fixation, we examined their localization in rice tissues by using catalyzed reporter deposition-fluorescence in situ hybridization (CARD-FISH). The methanotrophs were localized around the epidermal cells and vascular cylinder in the root tissues of the field-grown rice plants. Our metaproteomics and CARD-FISH results suggest that CH4 oxidation and N2 fixation are performed mainly by type II methanotrophs of the Methylocystaceae, including Methylosinus spp., inhabiting the vascular bundles and epidermal cells of rice roots. PMID:24928870

  20. Overexpressing Arabidopsis ABF3 increases tolerance to multiple abiotic stresses and reduces leaf size in alfalfa.

    PubMed

    Wang, Zhi; Su, Guoxia; Li, Min; Ke, Qingbo; Kim, Soo Young; Li, Hongbing; Huang, Jin; Xu, Bingcheng; Deng, Xi-Ping; Kwak, Sang-Soo

    2016-12-01

    Arabidopsis ABSCISIC ACID-RESPONSIVE ELEMENT-BINDING FACTOR 3 (ABF3), a bZIP transcription factor, plays an important role in regulating multiple stress responses in plants. Overexpressing AtABF3 increases tolerance to various stresses in several plant species. Alfalfa (Medicago sativa L.), one of the most important perennial forage crops worldwide, has high yields, high nutritional value, and good palatability and is widely distributed in irrigated and semi-arid regions throughout the world. However, drought and salt stress pose major constraints to alfalfa production. In this study, we developed transgenic alfalfa plants (cv. Xinjiang Daye) expressing AtABF3 under the control of the sweetpotato oxidative stress-inducible SWPA2 promoter (referred to as SAF plants) via Agrobacterium tumefaciens-mediated transformation. After drought stress treatment, we selected two transgenic lines with high expression of AtABF3, SAF5 and SAF6, for further characterization. Under normal conditions, SAF plants showed smaller leaf size compared to non-transgenic (NT) plants, while no other morphological changes were observed. Moreover, SAF plants exhibited enhanced drought stress tolerance and better growth under drought stress treatment, which was accompanied by a reduced transpiration rate and lower reactive oxygen species contents. In addition, SAF plants showed an increased tolerance to salt and oxidative stress. Therefore, these transgenic AtABF3 alfalfa plants might be useful for breeding forage crops with enhanced tolerance to environmental stress for use in sustainable agriculture on marginal lands.

  1. Analysis of Leaf and Root Transcriptome of Soil Grown Avena barbata Plants

    SciTech Connect

    Swarbreck, Sté; phanie,; Lindquist, Erika; Ackerly, David; Andersen, Gary

    2011-02-01

    Slender wild oat (Avena barbata) is an annual grass dominant in many grassland ecosystems in Mediterranean climate. This species has been the subject of ecological studies that aim at understanding the effect of global climate change on grassland ecosystems and the genetic basis for adaptation under varying environmental conditions. We present the sequencing and analysis of cDNA libraries constructed from leaf and root samples collected from A. barbata grown on natural soil and under varying rainfall patterns. More than one million expressed sequence tags (ESTs) were generated using both GS 454-FLX pyrosequencing and Sanger sequencing, and these tags were assembled into consensus sequences. We identified numerous candidate polymorphic markers in the dataset, providing possibilities for linking the genomic and the existing genetic information for A. barbata. Using the digital northern method, we showed that genes involved in photosynthesis were down regulated under high rainfall while stress- related genes were up regulated. We also identified a number of genes unique to the root library with unknown function. Real-time RT-PCR was used to confirm the root specificity of some of these transcripts such as two genes encoding O-methyl transferase. Also we showed differential expression under three water levels. Through a combination of Sanger and 454-based sequencing technologies, we were able to generate a large set of transcribed sequences for A. barbata. This dataset provides a platform for further studies of this important wild grass species

  2. Effects of chlorpyrifos and chlorantraniliprole on fermentation quality of alfalfa (Medicago sativa L.) silage inoculated with or without Lactobacillus plantarum LP.

    PubMed

    Zhang, Qing; Yu, Zhu; Wang, Xianguo; Na, Risu

    2017-03-01

    The effects of pesticides and Lactobacillus plantarum (LP) on fermentation quality of alfalfa (Medicago sativa L.) silage were investigated. Chlorpyrifos and chlorantraniliprole were sprayed on the surface of alfalfa plants at 658.6 and 45.0 g active ingredient/ha, respectively. Alfalfa plants were harvested on day 5 post-application and ensiled with or without LP. Chlorpyrifos and chlorantraniliprole decreased the yeast count of alfalfa material (P < 0.05). Both pesticides increased the butyric acid content of alfalfa silage (P < 0.001). Chlorpyrifos increased pH and decreased lactic acid, acetic acid and short-chain fatty acid contents (P < 0.05). LP decreased pH and butyric acid content, and increased lactic acid and short-chain fatty acid contents of alfalfa silage treated with pesticides (P < 0.05). LP increased the concentration of chlorpyrifos residue in alfalfa silage (P < 0.05). Chlorpyrifos and chlorantraniliprole affected the microbial communities of the material before ensiling, especially coliform bacteria and yeast; the two pesticide residues were reduced after the fermentation of alfalfa silage and affected the fermentation process, whereas LP improved the fermentation quality of pesticides-contaminated alfalfa silage and slowed down the dissipation of chlorpyrifos.

  3. Alternative control of Tetranychus evansi Baker & Pritchard (Acari: Tetranychidae) on tomato plants grown in greenhouses.

    PubMed

    Soto, Alberto; Venzon, Madelaine; Oliveira, Rafael M; Oliveira, Hamilton G; Pallini, Angelo

    2010-01-01

    Tetranychus evansi Baker & Pritchard is an important pest of solanaceous plants, including tomatoes. This mite is characterized by a high reproductive rate, which leads to high population growth in a short period of time causing important economic damage. Control of T. evansi is mainly through synthetic acaricides. In searching for environmentally friendly control measures, we evaluated the efficiency of alternative products to control T. evansi on tomato plants under greenhouse conditions. The products tested were lime sulphur and neem based products. We first estimated the lethal concentration (LC) and instantaneous rate of increase (r i) of T. evansi exposed to different product concentrations in laboratory conditions, and later tested the efficacy of LC95 and the concentrations that restrained mite population growth (r i = 0) in greenhouse conditions. The following treatments were repeated three times: NeemPro (81.0 and 71.6 mg a.i./l), Natuneem (31.1 and 20.4 mg ai/l), Organic Neem (39.1 and 30.4 mg a.i./l), lime sulphur (1.0 and 0.6%) and water (control). For all products, control provided by LC95 was higher than provided for lower concentrations (r i = 0) one day after spraying. However, after five days, for both concentrations, the percentage of T. evansi population reduction was superior to 95% and increased over time. Only plants sprayed with Natuneem (31.1 mg a.i./l) showed symptoms of phytotoxicity. Lime sulphur and neem based products, applied in appropriate concentrations and formulations, bear out as a viable alternative to control T. evansi on tomato plants.

  4. Effects of cadmium on cork oak (Quercus suber L.) plants grown in hydroponics.

    PubMed

    Gogorcena, Yolanda; Larbi, Ajmi; Andaluz, Sofia; Carpena, Ramón O; Abadía, Anunciación; Abadía, Javier

    2011-12-01

    Cork oak (Quercus suber L.) is an autochthonous tree species that is being used for reforestation in heavy-metal-contaminated areas in Spain. A hydroponics experiment was carried out to characterize the effects of Cd on several morphological and physiological parameters in this species, including shoot length, nutrient concentrations and allocation in different organs, leaf pigment concentrations, photosynthetic efficiency, root ferric chelate reductase (FCR) activity and organic acid concentrations in xylem sap. Four different Cd treatments were applied, adding Cd chelated with EDTA or as chloride salt at two different concentrations (10 and 50 µM Cd). After 1 month of Cd treatment, plant growth was significantly inhibited in all treatments. Results indicate that Cd accumulates in all organs 7- to 500-fold when compared with control plants. The highest Cd concentration was found in the 50 µM CdCl(2) treatment, which led to concentrations of ~30, 123 and 1153 µg Cd g(-1) dry weight in leaves, stems and roots, respectively. In the strongest Cd treatments the concentrations of P and Ca decreased in some plant parts, whereas the Mn leaf concentrations decreased with three of the four Cd treatments applied. The concentrations of chlorophyll and carotenoids on an area basis decreased, whereas the (zeaxanthin plus antheraxanthin)/(total violaxanthin cycle carotenoids) ratio and the non-photochemical quenching increased significantly in all Cd treatments. Cadmium treatments caused significant increases in the activity of the enzyme FCR in roots and in the concentrations of organic acids in xylem sap. Some of the physiological changes found support the fact that Cd induces a deficiency of Fe in cork oak, although the plant Fe concentrations were not reduced significantly. At higher concentrations the effects of Cd were more pronounced, and were more marked when Cd was in the free ion form than when present in the form of Cd-EDTA.

  5. Bioaccumulation of heavy metals in crop plants grown near Almeda Textile Factory, Adwa, Ethiopia.

    PubMed

    Gitet, Hintsa; Hilawie, Masho; Muuz, Mehari; Weldegebriel, Yirgaalem; Gebremichael, Dawit; Gebremedhin, Desta

    2016-09-01

    The contents of heavy metals cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni), lead (Pb), and zinc (Zn) present in water (wastewater and wetland), soils, and food crops collected from the vicinity of Almeda Textile Factory were quantified using Flame Atomic Absorption Spectrometer (FAAS) in order to assess the environmental impact of the textile factory. The contents of heavy metals determined in the wastewater were found below the recommended limit set by WHO and United States Environmental Protection Agency (US EPA) except for Cr, which was found slightly higher than WHO permissible limit. Besides, the contents of the heavy metals determined in soils were below the permissible level of FAO/WHO and Canada maximum allowable limits. Moreover, only the concentrations of Cd and Pb were found above the permissible level set by FAO/WHO in the crop plants studied. Generally, the mean concentrations of heavy metals in the plants were in the decreasing order of: Mn > Zn > Cu > Pb > Ni > Co > Cr > Cd. Nevertheless, higher bioconcentration factor (BCF) was found for Cd (0.108-1.156) followed by Zn (0.081-0.499). In conclusion, comparison of heavy metal concentrations with the permissible limits in all collected sample types i.e. water, soil, and crop plants did not show significant pollution from the factory.

  6. Effects of community versus single strain inoculants on the biocontrol of Salmonella and microbial community dynamics in alfalfa sprouts.

    PubMed

    Matos, Anabelle; Garland, Jay L

    2005-01-01

    Potential biological control inoculants, Pseudomonas fluorescens 2-79 and microbial communities derived from market sprouts or laboratory-grown alfalfa sprouts, were introduced into alfalfa seeds with and without a Salmonella inoculum. We examined their ability to inhibit the growth of this foodborne pathogen and assess the relative effects of the inoculants on the alfalfa microbial community structure and function. Alfalfa seeds contaminated with a Salmonella cocktail were soaked for 2 h in bacterial suspensions from each inoculant tested. Inoculated alfalfa seeds were grown for 7 days and sampled during days 1, 3, and 7. At each sampling, alfalfa sprouts were sonicated for 7 min to recover microflora from the surface, and the resulting suspensions were diluted and plated on selective and nonselective media. Total bacterial counts were obtained using acridine orange staining, and the percentage culturability was calculated. Phenotypic potential of sprout-associated microbial communities inoculated with biocontrol treatments was assessed using community-level physiological profiles based on patterns of use of 95 separate carbon sources in Biolog plates. Community-level physiological profiles were also determined using oxygen-sensitive fluorophore in BD microtiter plates to examine functional patterns in these communities. No significant differences in total and mesophilic aerobe microbial cell density or microbial richness resulting from the introduction of inoculants on alfalfa seeds with and without Salmonella were observed. P. fluorescens 2-79 exhibited the greatest reduction in the growth of Salmonella early during alfalfa growth (4.22 log at day 1), while the market sprout inoculum had the reverse effect, resulting in a maximum log reduction (5.48) of Salmonella on day 7. Community-level physiological profiles analyses revealed that market sprout communities peaked higher and faster compared with the other inoculants tested. These results suggest that

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

    NASA Astrophysics Data System (ADS)

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

    2016-02-01

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

  8. Prohexadione-calcium improves the establishment and yield of alfalfa interseeded as a dual purpose cover-forage crop into silage corn

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Interseeded alfalfa could serve as a dual purpose crop for providing groundcover during silage corn production and forage during subsequent years of production, but this system has been unworkable because competition between the co-planted crops often leads to stand failure of interseeded alfalfa an...

  9. Metal uptake by agricultural plant species grown in sludge-amended soil following ecosystem restoration practices

    SciTech Connect

    Peles, J.D.; Barrett, G.W.; Brewer, S.R.

    1996-12-01

    The disposal of municipal sewage sludge is an important environmental problem presently facing society. Because sludge is rich in plant nutrients such as nitrogen and phosphorous, land application as a fertilizer has been proposed as a cost-effective means of disposal. This method of disposal, however, is frequently the subject of public health concern since municipal sludge may contain heavy metals that potentially could be introduced into the human food chain. This study examined metal concentrations in two agricultural species at a study site where ecosystem restoration practices (liming and tilling) had been conducted for 5 years following 11 years of sludge enrichment. 11 refs., 2 tabs.

  10. Divergent alfalfa root system architecture is maintained across environment and nutrient supply

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant root system architecture can alter and be altered by soil fertility and other environmental conditions. In soils with suboptimal fertility, plant root length often is correlated with P and K uptake because these nutrients are supplied by diffusion. We developed alfalfa (Medicago sativa L.) pop...

  11. Potato leafhopper (Hemiptera: Cicadellidae) ecology and integrated pest management focused on alfalfa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Knowledge to date on biology of the potato leafhopper, Empoasca fabae (Harris), is summarized, including geographic distribution, development, migration, agricultural host plants, and the mechanism of injury to host plants. Damage to alfalfa, potato, soybean and snap bean, as well as treatment guide...

  12. Proteomic Identification of Differentially Expressed Proteins during Alfalfa (Medicago sativa L.) Flower Development.

    PubMed

    Chen, Lingling; Chen, Quanzhu; Zhu, Yanqiao; Hou, Longyu; Mao, Peisheng

    2016-01-01

    Flower development, pollination, and fertilization are important stages in the sexual reproduction process of plants; they are also critical steps in the control of seed formation and development. During alfalfa (Medicago sativa L.) seed production, some distinct phenomena such as a low seed setting ratio, serious flower falling, and seed abortion commonly occur. However, the causes of these phenomena are complicated and largely unknown. An understanding of the mechanisms that regulate alfalfa flowering is important in order to increase seed yield. Hence, proteomic technology was used to analyze changes in protein expression during the stages of alfalfa flower development. Flower samples were collected at pre-pollination (S1), pollination (S2), and the post-pollination senescence period (S3). Twenty-four differentially expressed proteins were successfully identified, including 17 down-regulated in pollinated flowers, one up-regulated in pollinated and senesced flowers, and six up-regulated in senesced flowers. The largest proportions of the identified proteins were involved in metabolism, signal transduction, defense response, oxidation reduction, cell death, and programmed cell death (PCD). Their expression profiles demonstrated that energy metabolism, carbohydrate metabolism, and amino acid metabolism provided the nutrient foundation for pollination in alfalfa. Furthermore, there were three proteins involved in multiple metabolic pathways: dual specificity kinase splA-like protein (kinase splALs), carbonic anhydrase, and NADPH: quinone oxidoreductase-like protein. Expression patterns of these proteins indicated that MAPK cascades regulated multiple processes, such as signal transduction, stress response, and cell death. PCD also played an important role in the alfalfa flower developmental process, and regulated both pollination and flower senescence. The current study sheds some light on protein expression profiles during alfalfa flower development and

  13. Proteomic Identification of Differentially Expressed Proteins during Alfalfa (Medicago sativa L.) Flower Development

    PubMed Central

    Chen, Lingling; Chen, Quanzhu; Zhu, Yanqiao; Hou, Longyu; Mao, Peisheng

    2016-01-01

    Flower development, pollination, and fertilization are important stages in the sexual reproduction process of plants; they are also critical steps in the control of seed formation and development. During alfalfa (Medicago sativa L.) seed production, some distinct phenomena such as a low seed setting ratio, serious flower falling, and seed abortion commonly occur. However, the causes of these phenomena are complicated and largely unknown. An understanding of the mechanisms that regulate alfalfa flowering is important in order to increase seed yield. Hence, proteomic technology was used to analyze changes in protein expression during the stages of alfalfa flower development. Flower samples were collected at pre-pollination (S1), pollination (S2), and the post-pollination senescence period (S3). Twenty-four differentially expressed proteins were successfully identified, including 17 down-regulated in pollinated flowers, one up-regulated in pollinated and senesced flowers, and six up-regulated in senesced flowers. The largest proportions of the identified proteins were involved in metabolism, signal transduction, defense response, oxidation reduction, cell death, and programmed cell death (PCD). Their expression profiles demonstrated that energy metabolism, carbohydrate metabolism, and amino acid metabolism provided the nutrient foundation for pollination in alfalfa. Furthermore, there were three proteins involved in multiple metabolic pathways: dual specificity kinase splA-like protein (kinase splALs), carbonic anhydrase, and NADPH: quinone oxidoreductase-like protein. Expression patterns of these proteins indicated that MAPK cascades regulated multiple processes, such as signal transduction, stress response, and cell death. PCD also played an important role in the alfalfa flower developmental process, and regulated both pollination and flower senescence. The current study sheds some light on protein expression profiles during alfalfa flower development and

  14. The uptake and distribution of selenium in three aquatic plants grown in Se(IV) solution.

    PubMed

    Mechora, Spela; Stibilj, Vekoslava; Germ, Mateja

    2013-03-15

    The uptake of Se(IV) by Myriophyllum spicatum, Ceratophyllum demersum and Potamogeton perfoliatus, and the effects of Se(IV) on their physiological and biochemical characteristics were studied. Plants were cultivated outdoors under semi-controlled conditions in water solution containing Na selenite (20 μg Se L(-1) and 10 mg Se L(-1)). The higher concentration of Se lowered the photochemical efficiency of PSII in all species studied, while the lower concentration had no effect on any species. The higher concentration of Se lowered respiratory potential in M. spicatum. The response of M. spicatum and C. demersum to Se(IV) regarding chlorophylls was variable, however in the majority of cases, there was a trend of increasing the amount of chlorophylls, while in P. perfoliatus the amount of chlorophyll a decreased. The concentration of Se in plants cultured in 10 mg Se(IV) L(-1) ranged from 436 to 839 μg Se g(-1) DM in M. spicatum, 319 to 988 μg Se g(-1) DM in C. demersum and 310 to 661 μg Se g(-1) DM in P. perfoliatus. The amount of soluble Se compounds in enzyme extracts of high Se treatment was 27% in M. spicatum, 41% in C. demersum and 35% in P. perfoliatus. Se compounds were determined using HPLC-ICP-MS. It was observed that the applied Se(IV) was mainly transformed to insoluble Se.

  15. The gravitropic response dynamics of wheat plants grown inside hemispherical greenhouse prototype

    NASA Astrophysics Data System (ADS)

    Zyablova, Natalya; Berkovich, Yuliy A.; Skripnikov, Alexander

    The characters of time course of gravicurvature (TCGC) of the 3-day wheat coleoptiles after a change in their orientation within the gravity field in dark and under red light are studied. It was found that maximal curvature angle and average rate of gravicurvature took place after 90 degrees of gravistimulation turn. Duration of the TCGC was registered in the range from 130 to 195 minutes. The estimates of red light (PPF of 30 µmol.m-2.s-1and 300 µmol.m-2.s-1) influence on 3-days coleoptiles TCGC are obtained. The reorganization of microtubules in dark and light during TCGC of wheat coleoptiles after changing their orientation from vertical to different angles is studied. The parameters of growth and development of wheat, cultivated during 5 weeks in rotating growth chamber of hemispherical on-ground prototype of space greenhouse were compared with stationary control crop. The wheat crop was cultivated under the hemispherical red-blue LEDs assembly with PPF of around 300 µmol.m-2.s-1. The plant growth chamber had diameter of 600mm and rotated 3 rph around of 2 perpendicular axes. Nutrient solution supply system regulated water potential in the range of (1,0 ± 0,45) kPa. The experiment showed that integral wheat gravitropic reactions inside rotating growth chamber under chosen illumination had not significant effect on growth and development of the plants.

  16. Radium-226 and calcium uptake by crops grown in mixtures of sand and cay tailings from phosphate mining

    SciTech Connect

    Million, J.B.; Sartain, J.B.; Gonzalez, R.X.; Carrier, W.D. III

    1994-07-01

    Radium-226 is a naturally occurring radionuclide found in reclaimed clay and sand tailing from phosphate mining. Field studies were conducted to investigate the effects of sand/clay ratio (SCR), Ca supplement and organic amendments on the {sup 226}Ra concentration in turnip, banana pepper, cabbage, yellow squash, mustard, and alfalfa. For vegetables, treatment effects included SCR (2:1, 4:1, 6:1, and 8:1), phosphogypsum (PG) 0,22, and 134 Mg ha{sup {minus}1}, and peat 0,100, and 200 Mg ha{sup {minus}1}. For alfalfa grown in a 1:1 SCR mixture, treatments included organic amendments (control, peat, sewage slude, sawdust, composted sewage sludge, composted garbage and humate) applied at 44.8 Mg ha{sup {minus}1} (2.2 Mg ha{sup {minus}1} for humate). Plant {sup 226}Ra concentration tended to be higher in the 4:1 than in the 2:1 SCR mix but this depended on the crop an d the season. Organic amendments and PG had no effect (p<0.05) on the {sup 226}Ra concentration in vegetables and alfalfa. Mean {sup 226}Ra concentration in plant tissues ranged from 3.4 Bq kg{sup {minus}1} in banana pepper fruit to 31.1 Bq kg{sup {minus}1}. A quadratic relationship based on 631 observations was observed between {sup 226}Ra and Ca concentration in plant tissues. The {sup 226}Ra/Ca ratio in plant tissues ranged from 0.85 to 2.13 kBq {sup 226}Ra kg{sup {minus}1} Ca and decreased with increasing plant {sup 226}Ra. Results indicated that wide differences in plant {sup 226}Ca concentration were related more to differences in plant Ca levels than to soil factors. 21 refs., 1 fig., 6 tabs.

  17. Ionic and osmotic relations in quinoa (Chenopodium quinoa Willd.) plants grown at various salinity levels.

    PubMed

    Hariadi, Yuda; Marandon, Karl; Tian, Yu; Jacobsen, Sven-Erik; Shabala, Sergey

    2011-01-01

    Ionic and osmotic relations in quinoa (Chenopodium quinoa Willd.) were studied by exposing plants to six salinity levels (0-500 mM NaCl range) for 70 d. Salt stress was administered either by pre-mixing of the calculated amount of NaCl with the potting mix before seeds were planted or by the gradual increase of NaCl levels in the irrigation water. For both methods, the optimal plant growth and biomass was achieved between 100 mM and 200 mM NaCl, suggesting that quinoa possess a very efficient system to adjust osmotically for abrupt increases in NaCl stress. Up to 95% of osmotic adjustment in old leaves and between 80% and 85% of osmotic adjustment in young leaves was achieved by means of accumulation of inorganic ions (Na(+), K(+), and Cl(-)) at these NaCl levels, whilst the contribution of organic osmolytes was very limited. Consistently higher K(+) and lower Na(+) levels were found in young, as compared with old leaves, for all salinity treatments. The shoot sap K(+) progressively increased with increased salinity in old leaves; this is interpreted as evidence for the important role of free K(+) in leaf osmotic adjustment under saline conditions. A 5-fold increase in salinity level (from 100 mM to 500 mM) resulted in only a 50% increase in the sap Na(+) content, suggesting either a very strict control of xylem Na(+) loading or an efficient Na(+) removal from leaves. A very strong correlation between NaCl-induced K(+) and H(+) fluxes was observed in quinoa root, suggesting that a rapid NaCl-induced activation of H(+)-ATPase is needed to restore otherwise depolarized membrane potential and prevent further K(+) leak from the cytosol. Taken together, this work emphasizes the role of inorganic ions for osmotic adjustment in halophytes and calls for more in-depth studies of the mechanisms of vacuolar Na(+) sequestration, control of Na(+) and K(+) xylem loading, and their transport to the shoot.

  18. Role of curli and plant cultivation conditions on Escherichia coli O157:H7 internalization into spinach grown on hydroponics and in soil.

    PubMed

    Macarisin, Dumitru; Patel, Jitendra; Sharma, Vijay K

    2014-03-03

    Contamination of fresh produce could represent a public health concern because no terminal kill step is applied during harvest or at the processing facility to kill pathogens. In addition, once contaminated, pathogens may internalize into produce and be protected from disinfectants during the postharvest processing step. The objective of the current study was to determine the potential internalization of Escherichia coli O157:H7 into spinach roots and subsequent transfer to the edible parts. Because curli are involved in biofilm formation, we investigated whether their presence influence the internalization of E. coli O157:H7 into spinach. Further, the effect of the spinach cultivar on E. coli O157:H7 internalization was evaluated. Spinach plants were grown in contaminated soil as well as hydroponically to prevent mechanical wounding of the roots and inadvertent transfer of pathogens from the contamination source to the non-exposed plant surfaces. Results showed that E. coli O157:H7 could internalize into hydroponically grown intact spinach plants through the root system and move to the stem and leaf level. The incidence of internalization was significantly higher in hydroponically grown plants when roots were exposed to 7 log CFU/mL compared to those exposed to 5 log CFU/mL. The effect of cultivar on E. coli O157:H7 internalization was not significant (P>0.05) for the analyzed spinach varieties, internalization incidences showing almost equal distribution between Space and Waitiki, 49.06% and 50.94% respectively. Wounding of the root system in hydroponically grown spinach increased the incidence of E. coli O157:H7 internalization and translocation to the edible portions of the plant. Experimental contamination of the plants grown in soil resulted in a greater number of internalization events then in those grown hydroponically, suggesting that E. coli O157:H7 internalization is dependent on root damage, which is more likely to occur when plants are grown in soil

  19. Phytoremediation potential of Cd and Zn by wetland plants, Colocasia esculenta L. Schott., Cyperus malaccensis Lam. and Typha angustifolia L. grown in hydroponics.

    PubMed

    Chayapan, P; Kruatrachue, M; Meetam, M; Pokethitiyook, P

    2015-09-01

    Cadmium and zinc phytoremediation potential of wetland plants, Colocasia esculenta, Cyperus malaccensis, and Typha angustifolia, was investigated. Plants were grown for 15 days in nutrient solutions containing various concentrations of Cd (0, 5, 10, 20, 50 mg l(-1)) and Zn (0, 10, 20, 50, 100 mg l(-1)). T angustifolia was tolerant to both metals as indicated by high RGR when grown in 50 mg I(-1) Cd and 100 mg I(-1) Zn solutions. All these plants accumulated more metals in their underground parts and > 100 mg kg(-1) in their aboveground with TF values < 1. Only C. esculenta could be considered a Zn hyperaccumulator because it could concentrate > 10,000 mg kg(-1) in its aboveground parts with TF > 1. T angustifolia exhibited highest biomass production and highest Cd and Zn uptake, confirming that this plant is a suitable candidate for treating of Cd contaminated soil/sediments.

  20. Alfalfa living mulch advances biological control of soybean aphid.

    PubMed

    Schmidt, Nicholas P; O'neal, Matthew E; Singer, Jeremy W

    2007-04-01

    Despite evidence for biological control in North America, outbreaks of the invasive soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), continue to occur on soybean (Glycine max L. Merr.). Our objectives were to determine whether natural enemies delay aphid establishment and limit subsequent population growth and whether biological control can be improved by altering the within-field habitat. We hypothesized that a living mulch would increase the abundance of the aphidophagous community in soybean and suppress A. glycines establishment and population growth. We measured natural enemy and A. glycines abundance in soybean grown with and without an alfalfa (Medicago sativa L.) living mulch. Soybean grown with an alfalfa living mulch had 45% more natural enemies and experienced a delay in A. glycines establishment that resulted in lower peak populations. From our experiments, we concluded that the current natural enemy community in Iowa can delay A. glycines establishment, and an increase in aphidophagous predator abundance lowered the rate of A. glycines population growth preventing economic populations (i.e., below the current economic threshold) from occurring. Incorporation of a living mulch had an unexpected impact on A. glycines population growth, lowering the aphids' intrinsic rate of growth, thus providing a bottom-up suppression of A. glycines. We suggest future studies of living mulches or cover crops for A. glycines management should address both potential sources of suppression. Furthermore, our experience suggests that more consistent biological control of A. glycines may be possible with even partial resistance that slows but does not prevent reproduction.

  1. Effects of CO2 enrichment and drought pretreatment on metabolite responses to water stress and subsequent rehydration using potato tubers from plants grown in sunlit SPAR chambers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Experiments were performed using naturally sunlit Soil–Plant–Atmosphere-Research chambers that provided ambient or elevated CO2. Potato plants were grown in pots that were water sufficient (W), water insufficient for 12 to 18 days during both vegetative and tuber development stages (VR), or water i...

  2. Elemental concentration of a native fern from Greece that grows in a monoculture and of corn plants grown in the same soil with different levels of copper

    SciTech Connect

    Procopiou, J.; Wallace, A.

    1982-07-01

    Analysis of a native fern (Pteridium aquilinum L.) growing in large tracts of soil at about 1200 meters mean sea level in Greece indicated that it tolerated low levels of copper. Corn plants (Zea mays L.) grown in potted soil from the area did respond slightly to Cu added to the soil.

  3. Dynamic changes of rhizosphere properties and antioxidant enzyme responses of wheat plants (Triticum aestivum L.) grown in mercury-contaminated soils.

    PubMed

    Li, Yonghua; Sun, Hongfei; Li, Hairong; Yang, Linsheng; Ye, Bixiong; Wang, Wuyi

    2013-10-01

    A pot experiment was conducted to investigate the dynamic changes in the rhizosphere properties and antioxidant enzyme responses of wheat plants (Triticum aestivum L.) grown in three levels of Hg-contaminated soils. The concentrations of soluble Hg and dissolved organic carbon (DOC) in the rhizosphere soil solutions of the wheat plants were characterised by the sequence before sowing>trefoil stage>stooling stage, whereas the soil solution pH was found to follow an opposite distribution pattern. The activities of antioxidant enzymes in wheat plants under Hg stress were substantially altered. Greater superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) activities were observed in the wheat plants grown in a highly polluted soil than in a slightly polluted soil (with increases of 11-27% at the trefoil stage and 26-70% at the stooling stage); however, increasing concentrations of Hg up to seriously polluted level led to reduced enzyme activities. The present results suggest that wheat plants could positively adapt to environmental Hg stress, with rhizosphere acidification, the enhancement of DOC production and greater antioxidant enzyme activities perhaps being three important mechanisms involved in the metal uptake/tolerance in the rhizospheres of wheat plants grown in Hg-contaminated soils.

  4. RNA-mediated gene silencing signals are not graft transmissible from the rootstock to the scion in greenhouse-grown apple plants Malus sp.

    PubMed

    Flachowsky, Henryk; Tränkner, Conny; Szankowski, Iris; Waidmann, Sascha; Hanke, Magda-Viola; Treutter, Dieter; Fischer, Thilo C

    2012-01-01

    RNA silencing describes the sequence specific degradation of RNA targets. Silencing is a non-cell autonomous event that is graft transmissible in different plant species. The present study is the first report on systemic acquired dsRNA-mediated gene silencing of transgenic and endogenous gene sequences in a woody plant like apple. Transgenic apple plants overexpressing a hairpin gene construct of the gusA reporter gene were produced. These plants were used as rootstocks and grafted with scions of the gusA overexpressing transgenic apple clone T355. After grafting, we observed a reduction of the gusA gene expression in T355 scions in vitro, but not in T355 scions grown in the greenhouse. Similar results were obtained after silencing of the endogenous Mdans gene in apple that is responsible for anthocyanin biosynthesis. Subsequently, we performed grafting experiments with Mdans silenced rootstocks and red leaf scions of TNR31-35 in order to evaluate graft transmitted silencing of the endogenous Mdans. The results obtained suggested a graft transmission of silencing signals in in vitro shoots. In contrast, no graft transmission of dsRNA-mediated gene silencing signals was detectable in greenhouse-grown plants and in plants grown in an insect protection tent.

  5. Redesigning alfalfa to reduce protein losses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alfalfa is often referred to as the “Queen of Forages” due to its relatively good digestibility, high protein, and ability to readily fix nitrogen. But there’s a big drawback to alfalfa – much of its protein is lost during the harvest and ensiling process, and more is lost in the rumen of livestock....

  6. The antenna-specific odorant-binding protein AlinOBP13 of the alfalfa plant bug Adelphocoris lineolatus is expressed specifically in basiconic sensilla and has high binding affinity to terpenoids.

    PubMed

    Sun, L; Xiao, H-J; Gu, S-H; Zhou, J-J; Guo, Y-Y; Liu, Z-W; Zhang, Y-J

    2014-08-01

    Odorant-binding proteins (OBPs) are crucial in the olfactory pathway of insects. In the present study, the antenna-enriched OBP AlinOBP13 was investigated because of its potential contribution to the peripheral olfactory perception in the alfalfa plant bug Adelphocoris lineolatus. The results of quantitative reverse transcriptase-PCR showed that the transcript level of AlinOBP13 was higher in the adult stage than in the nymph stages. The transcript levels of AlinOBP13 in the male and female antennae significantly increased after 4 and 8 h of starvation, respectively. Fine ultrastructures of different types of chemosensilla in both female and male antennae were investigated using transmission electron microscopy and immunocytochemical labelling. The results revealed that the anti-AlinOBP13 antiserum strongly and specifically labelled short basiconic sensilla; this antiserum was restricted to the inner lumen and the cavities below the sensillum base of the sensilla. By contrast, multiporous sensilla trichodea, medium long sensilla basiconica, and aporous sensilla chaetica were not labelled. The present study is the first to report an OBP showing specific expression in the short basiconic sensilla of a member of the Hemipteran species. The results of a fluorescence displacement binding assay indicated that recombinant AlinOBP13 showed a more specific binding preference to terpenoids than to sex pheromones and other classes of chemicals. This binding ability was dramatically affected by pH; higher binding affinities were displayed at pH 10.0 than at pH 7.4 and 5.0. In addition, the results of dose-dependent electroantennogram recordings from the antennae showed that both female and male adult bugs responded to the terpenoids tested, suggesting an apparent physiological relevance of AlinOBP13 in A. lineolatus chemoreception. The results of this study suggest that AlinOBP13 functions as a specific carrier of terpenoids and provide insights into the mechanism of A

  7. Subpicosecond surface dynamics in genomic DNA from in vitro-grown plant species: a SERS assessment.

    PubMed

    Muntean, Cristina M; Bratu, Ioan; Leopold, Nicolae; Morari, Cristian; Buimaga-Iarinca, Luiza; Purcaru, Monica A P

    2015-09-07

    In this work the surface-enhanced Raman total half band widths of seven genomic DNAs from leaves of chrysanthemum (Dendranthema grandiflora Ramat.), common sundew (Drosera rotundifolia L.), edelweiss (Leontopodium alpinum Cass), Epilobium hirsutum L., Hypericum richeri ssp. transsilvanicum (Čelak) Ciocârlan, rose (Rosa x hybrida L.) and redwood (Sequoia sempervirens D. Don. Endl.) have been measured. We have shown that surface-enhanced Raman spectroscopy (SERS) can be used to study the fast subpicosecond dynamics of DNA in the proximity of a metallic surface. The dependencies of the total half band widths and the global relaxation times, on the DNA molecular subgroup structure and on the type of genomic DNA, are reported. In our study, the full widths at half-maximum (FWHMs) for the SERS bands of genomic DNAs from different leaf tissues are typically in the wavenumber range from 15 to 55 cm(-1). Besides, it can be observed that molecular relaxation processes studied in this work have a global relaxation time smaller than 0.71 ps and larger than 0.19 ps. A comparison between different ranges of FT-Raman and SERS band parameters, respectively, corresponding to DNA extracted from leaf tissues is given. It is shown that the interaction between DNA and a metallic surface has the potential to lead to a shortening of the global relaxation times, as compared with molecular dynamics in solution. We have found that the surface dynamics of molecular subgroups in plant DNA is, in some cases, about two times faster than the solution dynamics of nucleic acids. This can be rationalized in a qualitative manner by invoking the complex landscape of the interaction energy between the molecule and the silver surface.

  8. Alleviating salt stress in tomato seedlings using Arthrobacter and Bacillus megaterium isolated from the rhizosphere of wild plants grown on saline-alkaline lands.

    PubMed

    Fan, Pengfei; Chen, Daitao; He, Yanan; Zhou, Qingxia; Tian, Yongqiang; Gao, Lihong

    2016-11-01

    Salt-induced soil degradation is common in farmlands and limits the growth and development of numerous crop plants in the world. In this study, we isolated salt-tolerant bacteria from the rhizosphere of Tamarix chinensis, Suaeda salsa and Zoysia sinica, which are common wild plants grown on a saline-alkaline land, to test these bacteria's efficiency in alleviating salt stress in tomato plants. We screened out seven strains (TF1-7) that are efficient in reducing salt stress in tomato seedlings. The sequence data of 16S rRNA genes showed that these strains belong to Arthrobacter and Bacillus megaterium. All strains could hydrolyze casein and solubilize phosphate, and showed at least one plant growth promotion (PGP)-related gene, indicating their potential in promoting plant growth. The Arthrobacter strains TF1 and TF7 and the Bacillus megaterium strain TF2 and TF3 could produce indole acetic acid under salt stress, further demonstrating their PGP potential. Tomato seed germination, seedling length, vigor index, and plant fresh and dry weight were enhanced by inoculation of Arthrobacter and B. megaterium strains under salt stress. Our results demonstrated that salt-tolerant bacteria isolated from the rhizosphere of wild plants grown on saline-alkaline lands could be used for alleviating salt stress in crop plants.

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

    USGS Publications Warehouse

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

    2016-01-01

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

  10. "allometry" Deterministic Approaches in Cell Size, Cell Number and Crude Fiber Content Related to the Physical Quality of Kangkong (Ipomoea reptans) Grown Under Different Plant Density Pressures

    NASA Astrophysics Data System (ADS)

    Selamat, A.; Atiman, S. A.; Puteh, A.; Abdullah, N. A. P.; Mohamed, M. T. M.; Zulkeefli, A. A.; Othman, S.

    Kangkong, especially the upland type (Ipomoea reptans) is popularly consumed as a vegetable dish in the South East Asian countries for its quality related to Vitamins (A and C) and crude fiber contents. Higher fiber contents would prevent from the occurrence of colon cancer and diverticular disease. With young stem edible portion, its cell number and size contribute to the stem crude fiber content. The mathematical approach of allometry of cell size, number, and fiber content of stem could be used in determining the 'best' plant density pressure in producing the quality young stem to be consumed. Basically, allometry is the ratio of relative increment (growth or change) rates of two parameters, or the change rate associated to the log of measured variables relationship. Kangkog grown equal or lower than 55 plants m-2 produced bigger individual plant and good quality (physical) kangkong leafy vegetable, but with lower total yield per unit area as compared to those grown at higher densities.

  11. Drench treatments for management of larval Japanese beetle (Coleoptera: Scarabaeidae) in field-grown balled and burlapped nursery plants.

    PubMed

    Oliver, Jason B; Reding, Michael E; Dennis, Sam O; Moyseenko, James J; Youssef, Nadeer N; Klein, Michael G; Callcott, Anne-Marie A; James, Shannon S; McAnally, Lee R; Bishop, Bert L

    2008-08-01

    Insecticide drenches were applied to postharvest field-grown nursery plants harvested as 60-cm-diameter balled and burlapped (B&B) root balls for controlling third instars of Japanese beetle, Popillia japonica Newman (Coleoptera: Scarabaeidae). Bifenthrin, chlorpyrifos, lambda-cyhalothrin, and thiamethoxam were drench-applied in fall and spring tests at volumes of runoff (1X; approximately equal 2.57 liters per drench per root ball) or twice runoff (2X). Tests also examined consecutive drenches (two, four, or six) and B&B rotation between drenches. Fall-applied drenches did not meet the Domestic Japanese Beetle Harmonization Plan (DJHP) standards of < or =1 grub and ranged from 0 to 90% control. However, most fall-applied drenches significantly reduced grub numbers relative to the untreated root balls. Spring-applied drenches were more effective than fall drenches: chlorpyrifos treatments gave 94-100% control, whereas other spring-applied treatments were less consistent, including thiamethoxam (83-100% control) and bifenthrin (61-100% control). Lambda-cyhalothrin was not effective. A higher drench volume (2X) did not significantly improve treatment efficacy; however, grub numbers decreased as the number of drenches increased for fall-applied chlorpyrifos and thiamethoxam and spring-applied bifenthrin. Rotation of root balls significantly reduced grub numbers compared with nonrotated treatments for fall-applied chlorpyrifos (six drenches) and bifenthrin (two or six drenches), but these treatments did not meet DJHP standards. The study indicates chlorpyrifos, bifenthrin, and thiamethoxam drenches can control Japanese beetle in the spring and may provide a new postharvest option to certify B&B plants for Japanese beetle.

  12. Effect of iron stress on Withania somnifera L.: antioxidant enzyme response and nutrient elemental uptake of in vitro grown plants.

    PubMed

    Rout, Jyoti Ranjan; Behera, Sadhana; Keshari, Nitin; Ram, Shidharth Sankar; Bhar, Subhajit; Chakraborty, Anindita; Sudarshan, Mathummal; Sahoo, Santi Lata

    2015-03-01

    In the present study the response of antioxidant enzyme activities and the level of expression of their corresponding genes on bioaccumulation of iron (Fe) were investigated. In vitro germinated Withania somnifera L. were grown in Murashige and Skoog's liquid medium with increasing concentrations (0, 25, 50, 100 and 200 µM) of FeSO4 for 7 and 14 days. Root and leaf tissues analyzed for catalase (CAT, EC 1.11.1.6), superoxide dismutase (SOD, EC 1.15.1.1) and guaiacol peroxidase (GPX, EC 1.11.1.7), have shown an increase in content with respect to exposure time. Isoforms of CAT, SOD and GPX were separated using non-denaturing polyacrylamide gel electrophoresis and observed that the isoenzymes were greatly affected by higher concentrations of Fe. Reverse transcriptase polymerase chain reaction analysis performed by taking three pairs of genes of CAT (RsCat, Catalase1, Cat1) and SOD (SodCp, TaSOD1.2, MnSOD) to find out the differential expression of antioxidant genes under Fe excess. RsCat from CAT and MnSOD from SOD have exhibited high levels of gene expression under Fe stress, which was consistent with the changes of the activity assayed in solution after 7 days of treatment. Analysis by proton induced X-ray emission exhibited an increasing uptake of Fe in plants by suppressing and expressing of other nutrient elements. The results of the present study suggest that higher concentration of Fe causes disturbance in nutrient balance and induces oxidative stress in plant.

  13. Proximate Composition of Seed and Biomass from Soybean Plants Grown at Different Carbon Dioxide (CO2) Concentrations

    NASA Technical Reports Server (NTRS)

    Wheeler, R. M.; Mackowiak, C. L.; Sager, J. C.

    1990-01-01

    Soybean plants were grown for 90 days at 500, 1000, 2000, and 5000 ubar (ppm) carbon dioxide (CO2) and compared for proximate nutritional value. For both cultivars (MC and PX), seed protein levels were highest at 1000 (39.3 and 41.9 percent for MC and PX) and lowest at 2000 (34.7 and 38.9 percent for MC and PX). Seed fat (oil) levels were highest at 2000 (21.2 and 20.9 percent for MC and PX) and lowest at 5000 (13.6 and 16.6 percent for MC and PX). Seed carbohydrate levels were highest at 500 (31.5 and 28.4 percent for MC and PX) and lowest at 2000 (20.9 and 20.8 percent for MC and PX). When adjusted for total seed yield per unit growing area, the highest production of protein and carbohydrate occurred with MC at 1000, while equally high amounts of fat were produced with MC at 1000 and 2000. Seed set and pod development at 2000 were delayed in comparison to other CO2 treatments; thus the proportionately high fat and low protein at 2000 may have been a result of the delay in plant maturity rather than CO2 concentration. Stem crude fiber and carbohydrate levels for both cultivars increased with increased CO2. Leaf protein and crude fiber levels also tended to rise with increased CO2 but leaf carbohydrate levels decreased as CO2 was increased. The results suggest that CO2 effects on total seed yield out-weighed any potential advantages to changes in seed composition.

  14. Accumulation and residue of napropamide in alfalfa (Medicago sativa) and soil involved in toxic response.

    PubMed

    Cui, Li E; Yang, Hong

    2011-06-15

    Napropamide belongs to the amide herbicide family and widely used to control weeds in farmland. Intensive use of the herbicide has resulted in widespread contamination to ecosystems. The present study demonstrated an analysis on accumulation of the toxic pesticide napropamide in six genotypes of alfalfa (Medicago sativa), along with biological parameters and its residues in soils. Soil was treated with napropamide at 3 mg kg(-1) dry soil and alfalfa plants were cultured for 10 or 30 d, respectively. The maximum value for napropamide accumulation is 0.426 mg kg(-1) in shoots and 2.444 mg kg(-1) in roots. The napropamide-contaminated soil with alfalfa cultivation had much lower napropamide concentrations than the control (soil without alfalfa cultivation). Also, the content of napropamide residue in the rhizosphere was significantly lower than that in the non-rhizosphere soil. M. sativa exposed to 3 mg kg(-1) napropamide showed inhibited growth. Further analysis revealed that plants treated with napropamide accumulated more reactive oxygen species (O(2)(-) and H(2)O(2)) and less amounts of chlorophyll. However, not all cultivars showed oxidative injury, suggesting that the alfalfa cultivars display different tolerance to napropamide.

  15. Nitrogen requirements of first-year corn following alfalfa were not altered by fall-applied manure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There are no published reports on the direct effects of fall manure application on alfalfa (Medicago sativa L.) N credits to first-year corn (Zea mays L.) grown as grain or silage. Therefore, on-farm experiments were conducted at eight locations in Minnesota to test whether manure applied during fal...

  16. Effects of water stress on photosynthesis and carbon partitioning in soybean (Glycine max (L. ) Merr. ) plants grown in the field at different CO/sub 2/ levels

    SciTech Connect

    Huber, S.C.; Rogers, H.H.; Mowry, F.L.

    1984-09-01

    The effects of water stress and CO/sub 2/ enrichment on photosynthesis, assimilate export, and sucrose-P synthase activity were examined in the field grown soybean plants. In general, leaves of plants grown in CO/sub 2/-enriched atmospheres (300 microliters per liter above unenriched control, which was 349 +/- 12 microliters per liter between 0500 and 1900 hours EST over the entire season) had higher carbon exchange rates (CER) compared to plants grown at ambient CO/sub 2/, but similar rates of export and similar activities of sucrose-P synthase. On most sample dates, essentially all of the extra carbon fixed as a result of CO/sub 2/ enrichment was partitioned into starch. CO/sub 2/-enriched plants had lower transpiration rates and therefore had a higher water use efficiency (milligrams CO/sub 2/ fixed per gram H/sub 2/O transpired) per unit leaf area compared to nonenriched plants. Water stress reduced CER in nonenriched plants to a greater extent than in CO/sub 2/-enriched plants. As CER declined, stomatal resistance increased, but this was not the primary cause of the decrease in assimilation because internal CO/sub 2/ concentration remained relatively constant. Export of assimilates was less affected by water stress than was CER. When CERs were low as a result of the imposed stress, export was supported by mobilization of reserves (mainly starch). Export rate and leaf sucrose concentration were related in a curvilinear manner. When sucrose concentration was above about 12 milligrams per square decimeter, obtained with nonstressed plants at high CO/sub 2/, there was no significant increase in export rate. Assimilate export rate was also correlated positively with SPS activity and the quantitative relationship varied with CER. Thus, export rate was a function of both CER and carbon partitioning. 28 references, 11 figures.

  17. Effects of Water Stress on Photosynthesis and Carbon Partitioning in Soybean (Glycine max [L.] Merr.) Plants Grown in the Field at Different CO(2) Levels.

    PubMed

    Huber, S C; Rogers, H H; Mowry, F L

    1984-09-01

    The effects of water stress and CO(2) enrichment on photosynthesis, assimilate export, and sucrose-P synthase activity were examined in field grown soybean plants. In general, leaves of plants grown in CO(2)-enriched atmospheres (300 microliters per liter above unenriched control, which was 349 +/- 12 microliters per liter between 0500 and 1900 hours EST over the entire season) had higher carbon exchange rates (CER) compared to plants grown at ambient CO(2), but similar rates of export and similar activities of sucrose-P synthase. On most sample dates, essentially all of the extra carbon fixed as a result of CO(2) enrichment was partitioned into starch. CO(2)-enriched plants had lower transpiration rates and therefore had a higher water use efficiency (milligrams CO(2) fixed per gram H(2)O transpired) per unit leaf area compared to nonenriched plants. Water stress reduced CER in nonenriched plants to a greater extent than in CO(2)-enriched plants. As CER declined, stomatal resistance increased, but this was not the primary cause of the decrease in assimilation because internal CO(2) concentration remained relatively constant. Export of assimilates was less affected by water stress than was CER. When CERs were low as a result of the imposed stress, export was supported by mobilization of reserves (mainly starch). Export rate and leaf sucrose concentration were related in a curvilinear manner. When sucrose concentration was above about 12 milligrams per square decimeter, obtained with nonstressed plants at high CO(2), there was no significant increase in export rate. Assimilate export rate was also correlated positively with SPS activity and the quantitative relationship varied with CER. Thus, export rate was a function of both CER and carbon partitioning.

  18. Quantification of Anti-Addictive Alkaloids Ibogaine and Voacangine in In Vivo- and In Vitro-Grown Plants of Two Mexican Tabernaemontana Species.

    PubMed

    Krengel, Felix; Herrera Santoyo, Josefina; Olivera Flores, Teresa de Jesús; Chávez Ávila, Víctor M; Pérez Flores, Francisco J; Reyes Chilpa, Ricardo

    2016-12-01

    Tabernaemontana alba and Tabernaemontana arborea are Apocynaceae species used in Mexican traditional medicine for which little phytochemical information exists. In this study, preliminary gas chromatography/mass spectrometry analyses of different organs obtained from wild plants of both species identified a total of 10 monoterpenoid indole alkaloids (MIAs) and one simple indole alkaloid, nine of which were reported for the first time in these species. Furthermore, callus cultures were established from T. alba leaf explants and regeneration of whole plants was accomplished via somatic embryogenesis. The anti-addictive MIAs ibogaine and voacangine were then quantified by gas chromatography with flame ionization detection in wild plants of both species, as well as greenhouse-grown plants, in vitro-grown plantlets and embryogenic callus of T. alba. Ibogaine and voacangine were present in most samples taken from the whole plants of both species, with stem and root barks showing the highest concentrations. No alkaloids were detected in callus samples. It was concluded that T. alba and T. arborea are potentially viable sources of ibogaine and voacangine, and that these MIAs can be produced through somatic embryogenesis and whole plant regeneration of T. alba. Approaches to increase MIA yields in whole plants and to achieve alkaloid production directly in cell cultures are discussed.

  19. Detection and isolation of Salmonella from naturally contaminated alfalfa seeds following an outbreak investigation.

    PubMed

    Inami, G B; Moler, S E

    1999-06-01

    Naturally contaminated alfalfa seeds, epidemiologically linked to foodborne disease outbreaks in Oregon and British Columbia, were tested for the presence of Salmonella. Ten sample units from the suspected lot were sprouted and grown for 4 days. After enrichment of the grown sprouts, an enzyme immunoassay (EIA) and culture method (modified procedure of the Food and Drug Administration Bacteriological Analytical Manual) were used for the detection and isolation of Salmonella. Four of the 10 sample units were positive with the EIA; however, 5 of the 10 sample units were culture positive (four were positive for Salmonella serotype Newport and a fifth was positive for Salmonella serotype Albany and serotype Schwarzengrund). The positive alfalfa seed sample units were further tested after shredding, soaking, and washing before culturing. Results suggest that sprouting and shredding methods may yield greater detection and recovery rates of Salmonella, but more research with a larger sample size is warranted.

  20. Transcriptome analysis of resistant and susceptible alfalfa cultivars infected with root-knot nematode Meloidogyne incognita.

    PubMed

    Postnikova, Olga A; Hult, Maria; Shao, Jonathan; Skantar, Andrea; Nemchinov, Lev G

    2015-01-01

    Nematodes are one of the major limiting factors in alfalfa production. Root-knot nematodes (RKN, Meloidogyne spp.) are widely distributed and economically important sedentary endoparasites of agricultural crops and they may inflict significant damage to alfalfa fields. As of today, no studies have been published on global gene expression profiling in alfalfa infected with RKN or any other plant parasitic nematode. Very little information is available about molecular mechanisms that contribute to pathogenesis and defense responses in alfalfa against these pests and specifically against RKN. In this work, we performed root transcriptome analysis of resistant (cv. Moapa 69) and susceptible (cv. Lahontan) alfalfa cultivars infected with RKN Meloidogyne incognita, widespread root-knot nematode species and a major pest worldwide. A total of 1,701,622,580 pair-end reads were generated on an Illumina Hi-Seq 2000 platform from the roots of both cultivars and assembled into 45,595 and 47,590 transcripts in cvs Moapa 69 and Lahontan, respectively. Bioinformatic analysis revealed a number of common and unique genes that were differentially expressed in susceptible and resistant lines as a result of nematode infection. Although the susceptible cultivar showed a more pronounced defense response to the infection, feeding sites were successfully established in its roots. Characteristically, basal gene expression levels under normal conditions differed between the two cultivars as well, which may confer advantage to one of the genotypes toward resistance to nematodes. Differentially expressed genes were subsequently assigned to known Gene Ontology categories to predict their functional roles and associated biological processes. Real-time PCR validated expression changes in genes arbitrarily selected for experimental confirmation. Candidate genes that contribute to protection against M. incognita in alfalfa were proposed and alfalfa-nematode interactions with respect to resistance

  1. A comparison of constitutive promoters for expression of transgenes in alfalfa (Medicago sativa).

    PubMed

    Samac, Deborah A; Tesfaye, Mesfin; Dornbusch, Melinda; Saruul, Purev; Temple, Stephen J

    2004-08-01

    The activity of constitutive promoters was compared in transgenic alfalfa plants using two marker genes. Three promoters, the 35S promoter from cauliflower mosaic virus (CaMV), the cassava vein mosaic virus (CsVMV) promoter, and the sugarcane bacilliform badnavirus (ScBV) promoter were each fused to the beta-glucuronidase (gusA) gene. The highest GUS enzyme activity was obtained using the CsVMV promoter and all alfalfa cells assayed by in situ staining had high levels of enzyme activity. The 35S promoter was expressed in leaves, roots, and stems at moderate levels, but the promoter was not active in stem pith cells, root cortical cells, or in the symbiotic zones of nodules. The ScBV promoter was active primarily in vascular tissues throughout the plant. In leaves, GUS activity driven by the CsVMV promoter was approximately 24-fold greater than the activity from the 35S promoter and 38-fold greater than the activity from the ScBV promoter. Five promoters, the double 35S promoter, figwort mosaic virus (FMV) promoter, CsVMV promoter, ScBV promoter, and alfalfa small subunit Rubisco (RbcS) promoter were used to control expression of a cDNA from Trichoderma atroviride encoding an endochitinase (ech42). Highest chitinase activity in leaves, roots, and root nodules was obtained in plants containing the CsVMV:ech42 transgene. Plants expressing the endochitinase were challenged with Phoma medicaginis var. medicaginis, the causal agent of spring black stem and leaf spot of alfalfa. Although endochitinase activity in leaves of transgenic plants was 50- to 2650-fold greater than activity in control plants, none of the transgenic plants showed a consistent increase in disease resistance compared to controls. The high constitutive levels of both GUS and endochitinase activity obtained demonstrate that the CsVMV promoter is useful for high-level transgene expression in alfalfa.

  2. Tritium dynamics in soils and plants grown under three irrigation regimes at a tritium processing facility in Canada.

    PubMed

    Mihok, S; Wilk, M; Lapp, A; St-Amant, N; Kwamena, N-O A; Clark, I D

    2016-03-01

    The dynamics of tritium released from nuclear facilities as tritiated water (HTO) have been studied extensively with results incorporated into regulatory assessment models. These models typically estimate organically bound tritium (OBT) for calculating public dose as OBT itself is rarely measured. Higher than expected OBT/HTO ratios in plants and soils are an emerging issue that is not well understood. To support the improvement of models, an experimental garden was set up in 2012 at a tritium processing facility in Pembroke, Ontario to characterize the circumstances under which high OBT/HTO ratios may arise. Soils and plants were sampled weekly to coincide with detailed air and stack monitoring. The design included a plot of native grass/soil, contrasted with sod and vegetables grown in barrels with commercial topsoil under natural rain and either low or high tritium irrigation water. Air monitoring indicated that the plume was present infrequently at concentrations of up to about 100 Bq/m(3) (the garden was not in a major wind sector). Mean air concentrations during the day on workdays (HTO 10.3 Bq/m(3), HT 5.8 Bq/m(3)) were higher than at other times (0.7-2.6 Bq/m(3)). Mean Tissue Free Water Tritium (TFWT) in plants and soils and OBT/HTO ratios were only very weakly or not at all correlated with releases on a weekly basis. TFWT was equal in soils and plants and in above and below ground parts of vegetables. OBT/HTO ratios in above ground parts of vegetables were above one when the main source of tritium was from high tritium irrigation water (1.5-1.8). Ratios were below one in below ground parts of vegetables when irrigated with high tritium water (0.4-0.6) and above one in vegetables rain-fed or irrigated with low tritium water (1.3-2.8). In contrast, OBT/HTO ratios were very high (9.0-13.5) when the source of tritium was mainly from the atmosphere. TFWT varied considerably through time as a result of SRBT's operations; OBT/HTO ratios showed no clear temporal

  3. The role of growth form and correlated traits in competitive ranking of six perennial ruderal plant species grown in unbalanced mixtures

    NASA Astrophysics Data System (ADS)

    Dietz, Hansjörg; Steinlein, Thomas; Ullmann, Isolde

    1998-02-01

    The competitive abilities of six perennial ruderal plants of three different growth forms were compared via yield measures using an additive diallel experimental design with unbalanced mixtures (9:3 or 3:9 plants per pot, respectively). Thus, in a given mixture species A was grown in two configurations: three individuals in centre position of the pot together with nine plants of species B in border position and vice versa. Effect competitive abilities as well as response competitive abilities of the species were significantly related to canopy height and plant biomass. The species with lower rosette growth form and smaller biomasses were weaker competitors than the species possessing elevated canopies along with higher biomasses, whereas total leaf area was not significantly correlated with competitive ability between species. Species differences in competitive ability were stronger between the plants grown in the central position than between those grown in the border position. Furthermore, interactions between species-specific traits and configuration could be observed, indicating the importance of species proportions and arrangement patterns for evaluation of competitive outcome in the field. The degree of complete transitivity of the competitive network of the six ruderal species, which was significantly higher than expected under the null model in our experimental design, also seemed to depend on species proportions in mixture. Shifts in root:shoot ratio of the centre plants when faced with competition by the border plants were in the direction of higher shoot allocation for the weak competitors with rosette growth form irrespective of the neighbour species, except for Bunias orientalis, which showed a more plastic response. The stronger competitors showed higher root allocation ( Urtica dioica) or were hardly affected at all. Consistent with the results of our experiment, the weaker competitors occur at rather frequently disturbed and therefore transient

  4. Changes in Whole-Plant Metabolism during the Grain-Filling Stage in Sorghum Grown under Elevated CO2 and Drought.

    PubMed

    De Souza, Amanda P; Cocuron, Jean-Christophe; Garcia, Ana Carolina; Alonso, Ana Paula; Buckeridge, Marcos S

    2015-11-01

    Projections indicate an elevation of the atmospheric CO2 concentration ([CO2]) concomitant with an intensification of drought for this century, increasing the challenges to food security. On the one hand, drought is a main environmental factor responsible for decreasing crop productivity and grain quality, especially when occurring during the grain-filling stage. On the other hand, elevated [CO2] is predicted to mitigate some of the negative effects of drought. Sorghum (Sorghum bicolor) is a C4 grass that has important economical and nutritional values in many parts of the world. Although the impact of elevated [CO2] and drought in photosynthesis and growth has been well documented for sorghum, the effects of the combination of these two environmental factors on plant metabolism have yet to be determined. To address this question, sorghum plants (cv BRS 330) were grown and monitored at ambient (400 µmol mol(-1)) or elevated (800 µmol mol(-1)) [CO2] for 120 d and subjected to drought during the grain-filling stage. Leaf photosynthesis, respiration, and stomatal conductance were measured at 90 and 120 d after planting, and plant organs (leaves, culm, roots, prop roots, and grains) were harvested. Finally, biochemical composition and intracellular metabolites were assessed for each organ. As expected, elevated [CO2] reduced the stomatal conductance, which preserved soil moisture and plant fitness under drought. Interestingly, the whole-plant metabolism was adjusted and protein content in grains was improved by 60% in sorghum grown under elevated [CO2].

  5. Variable salinity responses of 12 alfalfa genotypes and comparative expression analyses of salt-response genes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Twelve alfalfa genotypes that were selected for biomass under salinity, differences in Na and Cl concentrations in shoots and K/Na ratio were evaluated in this long-term salinity experiment. The selected plants were cloned to reduce genetic variability within each genotype. Salt tolerance (ST) index...

  6. Emergence, forage production, and ion relations of alfalfa in response to saline waters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alfalfa (Medicago sativa L) is an important crop utilized in regions under irrigation commonly impacted by salinity. In this study we evaluate the effect of salinity, as a continual process, from emergence to mature plant growth in successive harvests. We studied emergence, biomass production, salt ...

  7. Pythium and Fusarium species causing seed rot and damping-off of alfalfa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seed rot and damping-off is an important disease of alfalfa, severely affecting stand establishment when conditions favor the disease. This disease may have been overlooked as a cause of poor stand establishment and reduced vigor of adult plants. Globally, 15 Pythium species have been found to cause...

  8. Enhancing forage yields and soil conservation by interseeding alfalfa into silage corn

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent field studies have identified prohexadione-calcium (PHD) as an effective plant growth regulator for enhancing the establishment of alfalfa interseeded into corn as a dual-purpose cover and forage crop. Foliar applications of PHD on seedlings doubled or tripled stand survival of interseeded al...

  9. Alfalfa interseeded into silage corn can enhance productivity and soil and water conservation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alfalfa and corn silage are widely planted for dairy forage production systems throughout the northern regions of the USA, accounting for about 0.8 and 1.9 million hectares per year, respectively. Much of this area could benefit from strategies to reduce soil erosion and nutrient losses. Because the...

  10. Estimation of soil-to-plant transfer factors of radiocesium in 99 wild plant species grown in arable lands 1 year after the Fukushima 1 Nuclear Power Plant accident.

    PubMed

    Yamashita, Jun; Enomoto, Takashi; Yamada, Masao; Ono, Toshiro; Hanafusa, Tadashi; Nagamatsu, Tomohiro; Sonoda, Shoji; Yamamoto, Yoko

    2014-01-01

    One year after the deposition of radionuclides from the Fukushima 1 Nuclear Power Plant (A formal name is Fukushima Daiichi Nuclear Power Station) in March 2011, radiocesium (¹³⁴Cs, ¹³⁷Cs) concentrations ([Cs]) were comprehensively investigated in the wild plants of 99 species most of which were annual or summer green perennial herbs and started to grow from April 2012 at the heavily contaminated fields of paddy (three study sites) and upland (one study site) in Fukushima Prefecture. The survey was conducted three times (April, July and October) in the year. In each site, soils (soil cores of 5-cm depth) and plants (aerial shoots) were collected for determination of [Cs] on a dry weight basis, and then the transfer factor (TF) of radiocesium from soil to plant ([Cs]plant/[Cs]soil) was estimated in each species. The [Cs] values of both soils and plants largely varied. However, some species exhibited relatively high TF values (more than 0.4) (e.g., Athyrium yokoscense, Dryopteris tokyoensis, and Cyperus brevifolius), while others exhibited almost negligible values (less than 0.01) (e.g., Salix miyabeana, Humulus scandens, and Elymus tsukushiensis). In addition, judging from the 11 species grown in both paddy and upland fields, TF values were generally higher in the paddy fields. The estimation of phytoextraction efficiency of soil radiocesium by weed communities in the paddy fields suggests that the weed community is not a practical candidate for phytoremediation technique.

  11. Enhanced salt tolerance of alfalfa (Medicago sativa) by rstB gene transformation.

    PubMed

    Zhang, Wan-Jun; Wang, Tao

    2015-05-01

    Generating salt tolerance forage plant is essential for use of the land affected by high salinity. A salt tolerance gene rstB was used as a selectable marker gene in Agrobacterium-mediated transformation of tobacco under a selective regime of 170mM NaCl. The transgenic plants showed clear improvement in salt tolerance. To improve salt tolerance of alfalfa (Medicago sativa L.), rstB gene was introduced into alfalfa genome by Agrobacterium-mediated transformation. No abnormal phenotype was observed among the transgenic plants when compared with wild type (wt) plants. Significant enhancement of resistance to salt-shock treatment was noted on the rstB transgenic (T0) plants. Transgenic second-generation (T1) seeds showed improved germination rate and seedling growth under salt-stress condition. Hindered Na(+) accumulation, but enhanced Ca(2+) accumulation was observed on the rstB T1 plants when subjected to salt-stresses. Enhanced calcium accumulation in transgenic plants was also verified by cytohistochemical localization of calcium. Under salt-stress of 50mM NaCl, about 15% of the transgenic plants finished their life-cycle but the wt plants had no flower formation. The results demonstrated that the expression of rstB gene improved salt tolerance in transgenic alfalfa.

  12. Effect of bacterial root symbiosis and urea as source of nitrogen on performance of soybean plants grown hydroponically for Bioregenerative Life Support Systems (BLSSs)

    PubMed Central

    Paradiso, Roberta; Buonomo, Roberta; Dixon, Mike A.; Barbieri, Giancarlo; De Pascale, Stefania

    2015-01-01

    Soybean is traditionally grown in soil, where root symbiosis with Bradyrhizobium japonicum can supply nitrogen (N), by means of bacterial fixation of atmospheric N2. Nitrogen fertilizers inhibit N-fixing bacteria. However, urea is profitably used in soybean cultivation in soil, where urease enzymes of telluric microbes catalyze the hydrolysis to ammonium, which has a lighter inhibitory effect compared to nitrate. Previous researches demonstrated that soybean can be grown hydroponically with recirculating complete nitrate-based nutrient solutions. In Space, urea derived from crew urine could be used as N source, with positive effects in resource procurement and waste recycling. However, whether the plants are able to use urea as the sole source of N and its effect on root symbiosis with B. japonicum is still unclear in hydroponics. We compared the effect of two N sources, nitrate and urea, on plant growth and physiology, and seed yield and quality of soybean grown in closed-loop Nutrient Film Technique (NFT) in growth chamber, with or without inoculation with B. japonicum. Urea limited plant growth and seed yield compared to nitrate by determining nutrient deficiency, due to its low utilization efficiency in the early developmental stages, and reduced nutrients uptake (K, Ca, and Mg) throughout the whole growing cycle. Root inoculation with B. japonicum did not improve plant performance, regardless of the N source. Specifically, nodulation increased under fertigation with urea compared to nitrate, but this effect did not result in higher leaf N content and better biomass and seed production. Urea was not suitable as sole N source for soybean in closed-loop NFT. However, the ability to use urea increased from young to adult plants, suggesting the possibility to apply it during reproductive phase or in combination with nitrate in earlier developmental stages. Root symbiosis did not contribute significantly to N nutrition and did not enhance the plant ability to use

  13. Stomatal and mesophyll conductances to CO2 are the main limitations to photosynthesis in sugar beet (Beta vulgaris) plants grown with excess zinc.

    PubMed

    Sagardoy, R; Vázquez, S; Florez-Sarasa, I D; Albacete, A; Ribas-Carbó, M; Flexas, J; Abadía, J; Morales, F

    2010-07-01

    *The effects of zinc (Zn) toxicity on photosynthesis and respiration were investigated in sugar beet (Beta vulgaris) plants grown hydroponically with 1.2, 100 and 300 microM Zn. *A photosynthesis limitation analysis was used to assess the stomatal, mesophyll, photochemical and biochemical contributions to the reduced photosynthesis observed under Zn toxicity. *The main limitation to photosynthesis was attributable to stomata, with stomatal conductances decreasing by 76% under Zn excess and stomata being unable to respond to physiological and chemical stimuli. The effects of excess Zn on photochemistry were minor. Scanning electron microscopy showed morphological changes in stomata and mesophyll tissue. Stomatal size and density were smaller, and stomatal slits were sealed in plants grown under high Zn. Moreover, the mesophyll conductance to CO(2) decreased by 48% under Zn excess, despite a marked increase in carbonic anhydrase activity. Respiration, including that through both cytochrome and alternative pathways, was doubled by high Zn. *It can be concluded that, in sugar beet plants grown in the presence of excess Zn, photosynthesis is impaired due to a depletion of CO(2) at the Rubisco carboxylation site, as a consequence of major decreases in stomatal and mesophyll conductances to CO(2).

  14. Inoculating Helianthus annuus (sunflower) grown in zinc and cadmium contaminated soils with plant growth promoting bacteria--effects on phytoremediation strategies.

    PubMed

    Marques, Ana P G C; Moreira, Helena; Franco, Albina R; Rangel, António O S S; Castro, Paula M L

    2013-06-01

    Plant growth promoting bacteria (PGPR) may help reducing the toxicity of heavy metals to plants in polluted environments. In this work the effects of inoculating metal resistant and plant growth promoting bacterial strains on the growth of Helianthus annuus grown in Zn and Cd spiked soils were assessed. The PGPR strains Ralstonia eutropha (B1) and Chrysiobacterium humi (B2) reduced losses of weight in metal exposed plants and induced changes in metal bioaccumulation and bioconcentration - with strain B2 decreasing up to 67% Zn accumulation and by 20% Zn bioconcentration factor (BCF) in the shoots, up to 64% Zn uptake and 38% Zn BCF in the roots, and up to 27% Cd uptake and 27% Cd BCF in plant roots. The impact of inoculation on the bacterial communities in the rhizosphere of the plant was also assessed. Bacterial community diversity decreased with increasing levels of metal contamination in the soil, but in rhizosphere soil of plants inoculated with the PGPR strains, a higher bacterial diversity was kept throughout the experimental period. Inoculation of sunflower, particularly with C. humi (B2), appears to be an effective way of enhancing the short term stabilization potential of the plant in metal contaminated land, lowering losses in plant biomass and decreasing aboveground tissue contamination.

  15. Characterization of plant growth promoting traits of bacterial isolates from the rhizosphere of barley (Hordeum vulgare L.) and tomato (Solanum lycopersicon L.) grown under Fe sufficiency and deficiency.

    PubMed

    Scagliola, M; Pii, Y; Mimmo, T; Cesco, S; Ricciuti, P; Crecchio, C

    2016-10-01

    Plant Growth Promoting Bacteria (PGPB) are considered a promising approach to replace the conventional agricultural practices, since they have been shown to affect plant nutrient-acquisition processes by influencing nutrient availability in the rhizosphere and/or those biochemical processes determining the uptake at root level of nitrogen (N), phosphorus (P), and iron (Fe), that represent the major constraints for crop productivity worldwide. We have isolated novel bacterial strains from the rhizosphere of barley (Hordeum vulgare L.) and tomato (Solanum lycopersicon L.) plants, previously grown in hydroponic solution (either Fe deficient or Fe sufficient) and subsequently transferred onto an agricultural calcareous soil. PGPB have been identified by molecular tools and characterized for their capacity to produce siderophores and indole-3-acetic acid (IAA), and to solubilize phosphate. Selected bacterial isolates, showing contemporarily high levels of the three activities investigated, were finally tested for their capacity to induce Fe reduction in cucumber roots two isolates, from barley and tomato plants under Fe deficiency, significantly increased the root Fe-chelate reductase activity; interestingly, another isolate enhanced the reduction of Fe-chelate reductase activity in cucumber plant roots, although grown under Fe sufficiency.

  16. Zinc distribution and speciation within rocket plants (Eruca vesicaria L. Cavalieri) grown on a polluted soil amended with compost as determined by XRF microtomography and micro-XANES.

    PubMed

    Terzano, Roberto; Al Chami, Ziad; Vekemans, Bart; Janssens, Koen; Miano, Teodoro; Ruggiero, Pacifico

    2008-05-14

    Zinc distribution and speciation within different organs (root, petiole, and leaf) of the edible plant Eruca vesicaria L. Cavalieri were determined using synchrotron microbeam X-ray techniques (XRF microtomography and mu-XANES) for plants grown in polluted soil with or without compost amendment. Data on soil derived from different extraction procedures and using mu-XANES analyses on rhizospheric soil indicated that compost amendment did not significantly influence the Zn speciation and availability in soil. However, major differences were observed within the plants. Plants grown in the presence of compost were able to partly block zinc immediately outside the root endodermis in the form of zinc-phytate, while a smaller Zn fraction was allowed to xylem transport as zinc-citrate. In the leaves, zinc was largely excluded from leaf cells, and about approximately 50% was in the form of phosphate precipitates, and the other 50% was complexed by cysteine and histidine residues. The reported data provide new information concerning the mechanisms of zinc tolerance in E. vesicaria L. Cavalieri, a very common edible plant in Mediterranean regions, and on the role of compost in influencing the molecular strategies involved in zinc uptake and detoxification.

  17. Effect of Arbuscular Mycorrhizal Fungi on Plant Biomass and the Rhizosphere Microbial Community Structure of Mesquite Grown in Acidic Lead/Zinc Mine Tailings

    PubMed Central

    Solís-Domínguez, Fernando A.; Valentín-Vargas, Alexis; Chorover, Jon; Maier, Raina M.

    2011-01-01

    Mine tailings in arid and semi-arid environments are barren of vegetation and subject to eolian dispersion and water erosion. Revegetation is a cost-effective strategy to reduce erosion processes and has wide public acceptance. A major cost of revegetation is the addition of amendments, such as compost, to allow plant establishment. In this paper we explore whether arbuscular mycorrhizal fungi (AMF) can help support plant growth in tailings at a reduced compost concentration. A greenhouse experiment was performed to determine the effects of three AMF inocula on biomass, shoot accumulation of heavy metals, and changes in the rhizosphere microbial community structure of the native plant Prosopis juliflora (mesquite). Plants were grown in an acidic lead/zinc mine tailings amended with 10% (w/w) compost amendment, which is slightly sub-optimal for plant growth in these tailings. After two months, AMF-inoculated plants showed increased dry biomass and root length (p < 0.05) and effective AMF colonization compared to controls grown in uninoculated compost-amended tailings. Mesquite shoot tissue lead and zinc concentrations did not exceed domestic animal toxicity limits regardless of whether AMF inoculation was used. The rhizosphere microbial community structure was assessed using denaturing gradient gel electrophoresis (DGGE) profiles of the small subunit RNA gene for bacteria and fungi. Canonical correspondence analysis (CCA) of DGGE profiles showed that the rhizosphere fungal community structure at the end of the experiment was significantly different from the community structure in the tailings, compost, and AMF inocula prior to planting. Further, CCA showed that AMF inoculation significantly influenced the development of both the fungal and bacterial rhizosphere community structures after two months. The changes observed in the rhizosphere microbial community structure may be either a direct effect of the AMF inocula, caused by changes in plant physiology induced by

  18. Effect of arbuscular mycorrhizal fungi on plant biomass and the rhizosphere microbial community structure of mesquite grown in acidic lead/zinc mine tailings.

    PubMed

    Solís-Domínguez, Fernando A; Valentín-Vargas, Alexis; Chorover, Jon; Maier, Raina M

    2011-02-15

    Mine tailings in arid and semi-arid environments are barren of vegetation and subject to eolian dispersion and water erosion. Revegetation is a cost-effective strategy to reduce erosion processes and has wide public acceptance. A major cost of revegetation is the addition of amendments, such as compost, to allow plant establishment. In this paper we explore whether arbuscular mycorrhizal fungi (AMF) can help support plant growth in tailings at a reduced compost concentration. A greenhouse experiment was performed to determine the effects of three AMF inocula on biomass, shoot accumulation of heavy metals, and changes in the rhizosphere microbial community structure of the native plant Prosopis juliflora (mesquite). Plants were grown in an acidic lead/zinc mine tailings amended with 10% (w/w) compost amendment, which is slightly sub-optimal for plant growth in these tailings. After two months, AMF-inoculated plants showed increased dry biomass and root length (p<0.05) and effective AMF colonization compared to controls grown in uninoculated compost-amended tailings. Mesquite shoot tissue lead and zinc concentrations did not exceed domestic animal toxicity limits regardless of whether AMF inoculation was used. The rhizosphere microbial community structure was assessed using denaturing gradient gel electrophoresis (DGGE) profiles of the small subunit RNA gene for bacteria and fungi. Canonical correspondence analysis (CCA) of DGGE profiles showed that the rhizosphere fungal community structure at the end of the experiment was significantly different from the community structure in the tailings, compost, and AMF inocula prior to planting. Further, CCA showed that AMF inoculation significantly influenced the development of both the fungal and bacterial rhizosphere community structures after two months. The changes observed in the rhizosphere microbial community structure may be either a direct effect of the AMF inocula, caused by changes in plant physiology induced by

  19. Preservation and Faithful Expression of Transgene via Artificial Seeds in Alfalfa

    PubMed Central

    Liu, Wenting; Liang, Zongsuo; Wang, Xinhua; Sibbald, Susan; Hunter, David; Tian, Lining

    2013-01-01

    Proper preservation of transgenes and transgenic materials is important for wider use of transgenic technology in plants. Here, we report stable preservation and faithful expression of a transgene via artificial seed technology in alfalfa. DNA constructs containing the uid reporter gene coding for β-glucuronidase (GUS) driven by a 35S promoter or a tCUP promoter were introduced into alfalfa via Agrobacterium-mediated genetic transformation. Somatic embryos were subsequently induced from transgenic alfalfa plants via in vitro technology. These embryos were treated with abscisic acid to induce desiccation tolerance and were subjected to a water loss process. After the desiccation procedure, the water content in dried embryos, or called artificial seeds, was about 12–15% which was equivalent to that in true seeds. Upon water rehydration, the dried somatic embryos showed high degrees of viability and exhibited normal germination. Full plants were subsequently developed and recovered in a greenhouse. The progeny plants developed from artificial seeds showed GUS enzyme activity and the GUS expression level was comparable to that of plants developed from somatic embryos without the desiccation process. Polymerase chain reaction analysis indicated that the transgene was well retained in the plants and Southern blot analysis showed that the transgene was stably integrated in plant genome. The research showed that the transgene and the new trait can be well preserved in artificial seeds and the progeny developed. The research provides a new method for transgenic germplasm preservation in different plant species. PMID:23690914

  20. Health status of alfalfa leafcutting bee larvae (Hymenoptera: Megachilidae) in commercial United States alfalfa seed fields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We conducted a geographically large survey to quantify production losses in the alfalfa leafcutting bee (Megachile rotundata, Hymenoptera: Megachilidae), a solitary pollinator used extensively in alfalfa seed production. Healthy prepupae were found in only 47.1% of the nest cells collected at the en...

  1. Gene Expression Analysis of Alfalfa Seedlings Response to Acid-Aluminum

    PubMed Central

    Lv, Aimin; Wang, Shengyin; Huang, Bingru

    2016-01-01

    Acid-Aluminum (Al) is toxic to plants and greatly affects crop production worldwide. To understand the responses of plants to acid soils and Aluminum toxicity, we examined global gene expression using microarray data in alfalfa seedlings with the treatment of acid-Aluminum. 3,926 genes that were identified significantly up- or downregulated in response to Al3+ ions with pH 4.5 treatment, 66.33% of which were found in roots. Their functional categories were mainly involved with phytohormone regulation, reactive oxygen species, and transporters. Both gene ontology (GO) enrichment and KEGG analysis indicated that phenylpropanoid biosynthesis, phenylalanine metabolism, and flavonoid biosynthesis played a critical role on defense to Aluminum stress in alfalfa. In addition, we found that transcription factors such as the MYB and WRKY family proteins may be also involved in the regulation of reactive oxygen species reactions and flavonoid biosynthesis. Thus, the finding of global gene expression profile provided insights into the mechanisms of plant defense to acid-Al stress in alfalfa. Understanding the key regulatory genes and pathways would be advantageous for improving crop production not only in alfalfa but also in other crops under acid-Aluminum stress. PMID:28074175

  2. Soil factors exhibit greater influence than bacterial inoculation on alfalfa growth and nitrogen fixation.

    PubMed

    Neumann, Ute; Kosier, Bob; Jahnke, Joachim; Priefer, Ursula B; Al-Halbouni, Djamila

    2011-09-01

    In order to study the effects of soil factors and bacterial inoculation on alfalfa (Medicago sativa), plants were inoculated with Ensifer meliloti L33 and Azospirillum brasilense Sp7 in pot experiments using two different soils separately as well as in a mixture. One soil was contaminated with chemical waste products; the other was an arable soil. Soil factors, including the availability of macro- and micronutrients as well as carbon and nitrogen contents, were found to exhibit a much greater influence on the growth of alfalfa than any of the inoculations. In contaminated soil, the shoot and root growth of alfalfa was decreased and nodules were diminished and ineffective. Bacterial inoculations did not significantly improve this hostile growth environment. However, in a mixture (44% arable, 22% contaminated soil, 34% vermiculite), growth conditions for alfalfa were improved so that shoot dry weight and nodule numbers increased up to 100- and 20-fold, respectively, compared with the contaminated soil. For the strain L33, its persistence in the rhizosphere was correlated to the presence of its host plant, but its dynamics were influenced by competition with indigenous rhizobia. The strain Sp7, once provided with a suitable soil, was not dependent on the plant's rhizosphere, but it enhanced the performance of L33 and native rhizobia.

  3. Selective lignin downregulation leads to constitutive defense response expression in alfalfa (Medicago sativa L.).

    PubMed

    Gallego-Giraldo, Lina; Jikumaru, Yusuke; Kamiya, Yuji; Tang, Yuhong; Dixon, Richard A

    2011-05-01

    • Downregulation of hydroxycinnamoyl CoA: shikimate hydroxycinnamoyl transferase (HCT) in alfalfa (Medicago sativa) reduces lignin levels and improves forage quality and saccharification efficiency for bioethanol production. However, the plants have reduced stature. It was previously reported that HCT-down-regulated Arabidopsis have impaired auxin transport, but this has recently been disproved. • To address the basis for the phenotypes of lignin-modified alfalfa, we measured auxin transport, profiled a range of metabolites including flavonoids and hormones, and performed in depth transcriptome analyses. • Auxin transport is unaffected in HCT antisense alfalfa despite increased flavonoid biosynthesis. The plants show increased cytokinin and reduced auxin levels, and gibberellin levels and sensitivity are both reduced. Levels of salicylic, jasmonic and abscisic acids are elevated, associated with massive upregulation of pathogenesis and abiotic stress-related genes and enhanced tolerance to fungal infection and drought. • We suggest that HCT downregulated alfalfa plants exhibit constitutive activation of defense responses, triggered by release of bioactive cell wall fragments and production of hydrogen peroxide as a result of impaired secondary cell wall integrity.

  4. Enhanced Botrytis cinerea resistance of Arabidopsis plants grown in compost may be explained by increased expression of defense-related genes, as revealed by microarray analysis.

    PubMed

    Segarra, Guillem; Santpere, Gabriel; Elena, Georgina; Trillas, Isabel

    2013-01-01

    Composts are the products obtained after the aerobic degradation of different types of organic matter waste and can be used as substrates or substrate/soil amendments for plant cultivation. There is a small but increasing number of reports that suggest that foliar diseases may be reduced when using compost, rather than standard substrates, as growing medium. The purpose of this study was to examine the gene expression alteration produced by the compost to gain knowledge of the mechanisms involved in compost-induced systemic resistance. A compost from olive marc and olive tree leaves was able to induce resistance against Botrytis cinerea in Arabidopsis, unlike the standard substrate, perlite. Microarray analyses revealed that 178 genes were differently expressed, with a fold change cut-off of 1, of which 155 were up-regulated and 23 were down-regulated in compost-grown, as against perlite-grown plants. A functional enrichment study of up-regulated genes revealed that 38 Gene Ontology terms were significantly enriched. Response to stress, biotic stimulus, other organism, bacterium, fungus, chemical and abiotic stimulus, SA and ABA stimulus, oxidative stress, water, temperature and cold were significantly enriched, as were immune and defense responses, systemic acquired resistance, secondary metabolic process and oxireductase activity. Interestingly, PR1 expression, which was equally enhanced by growing the plants in compost and by B. cinerea inoculation, was further boosted in compost-grown pathogen-inoculated plants. Compost triggered a plant response that shares similarities with both systemic acquired resistance and ABA-dependent/independent abiotic stress responses.

  5. Greenhouse (III): Gas-Exchange and Seed-to-Seed Experiments on the Russian Space Station MIR and Earth-grown, Ethylene-Treated Wheat Plants

    NASA Technical Reports Server (NTRS)

    Campbell, William F.; Bingham, Gail; Carman, John; Bubenheim, David; Levinskikh, Margarita; Sytchev, Vladimir N.; Podolsky, Igor B.; Chernova, Lola; Nefodova, Yelena

    2001-01-01

    The Mir Space Station provided an outstanding opportunity to study long-term plant responses when exposed to a microgravity environment. Furthermore, if plants can be grown to maturity in a microgravity environment, they might be used in future bioregenerative life-support systems (BLSS). The primary objective of the Greenhouse experiment onboard Mir was to grow Super Dwarf and Apogee wheat through complete life cycles in microgravity; i.e., from seed-to-seed-to-seed. Additional objectives were to study chemical, biochemical, and structural changes in plant tissues as well as photosynthesis, respiration, and transpiration (evaporation of water from plants). Another major objective was to evaluate the suitability clothe facilities on Mir for advanced research with plants. The Greenhouse experiment was conducted in the Russian/Bulgarian plant growth chamber, the Svet, to which the United States added instrumentation systems to monitor changes in CO2 and water vapor caused by the plants (with four infrared gas analyzers monitoring air entering and leaving two small plastic chambers). In addition, the US instrumentation also monitored O2; air, leaf (IR), cabin pressure; photon flux; and substrate temperature and substrate moisture (16 probes in the root module). Facility modifications were first performed during the summer of 1995 during Mir 19, which began after STS-72 left Mir. Plant development was monitored by daily observations and some photographs.

  6. Evaluation of variations in CO2 gas exchange in the atmosphere of the BTLSS with plants grown in a conveyor mode on the soil-like substrate

    NASA Astrophysics Data System (ADS)

    Velichko, Vladimir; Tikhomirov, Alexander A.; Tikhomirova, Natalia; Ushakova, Sofya

    2016-07-01

    The soil-like substrate (SLS) included in the bioregenerative life support system (BLSS) exerts a substantial effect on its gas exchange. This effect is determined by the non-uniform rate of organic matter degradation in the SLS, on the one hand, and by the variable intensity of photosynthesis of the plants grown on it, on the other. The purpose of this study was to compare CO2 variations in the atmosphere of the higher plants - SLS system at different intervals in uneven-aged higher plant conveyers. The study showed that CO2 concentration could reach and exceed the levels of atmospheric carbon dioxide acceptable for humans (over 1%) even when the conveyer interval was rather short. CO2 variations in the atmosphere of the higher plants - SLS system were determined not only by the frequency of adding plant waste to the SLS and the mass of the waste but also by the amount of the harvested actively photosynthesizing plant biomass. At the same time, no significant differences were found in the mineral and production components between the plants in different experiments. Results of the study can be used to optimize the conveyor interval and the associated effectiveness of mineralization of the plant waste added to the SLS and to stabilize the CO2 gas exchange. This study was carried out in the IBP SB RAS and supported by the grant of the Russian Science Foundation (Project No. 14-14-00599).

  7. Plant growth and metal distribution in tissues of Prosopis juliflora-velutina grown on chromium contaminated soil in the presence of Glomus deserticola

    PubMed Central

    Arias, Jack A.; Peralta-Videa, Jose R.; Ellzey, Joanne T.; Viveros, Marian N.; Ren, Minghua; Mokgalaka-Matlala, Ntebogeng S.; Castillo-Michel, Hiram; Gardea-Torresdey, Jorge L.

    2015-01-01

    Arbuscular mycorrhizal fungi have been known to increase metal uptake in plants. In this study, mesquite (Prosopis juliflora-velutina) inoculated with Glomus deserticola or amended with EDTA were grown for 30 days in soil containing Cr(III) or Cr(VI) at 0, 40, 80, and 160 mg kg−1. Total amylase activity (TAA) was monitored as a stress indicator. Element concentrations and distribution in tissue were determined using ICP-OES, electron scanning microprobe, and TEM. Inoculated Cr(VI) treated plants had 21% and 30% more Cr than uninoculated and EDTA treated roots, respectively, at 80 mg Cr kg−1 treatment. In the case of Cr(III), EDTA produced the highest Cr accumulation in roots. TAA was higher in inoculated plants grown with Cr(III) at 80 and 160 mg kg−1 and Cr(VI) at 40 and 160 mg kg−1. The X-ray mapping showed higher metal concentrations in the vascular system of inoculated plants and the TEM micrographs demonstrated the presence of G. deserticola in roots. PMID:20795657

  8. Plant growth and metal distribution in tissues of Prosopis juliflora-velutina grown on chromium contaminated soil in the presence of Glomus deserticola.

    PubMed

    Arias, Jack A; Peralta-Videa, Jose R; Ellzey, Joanne T; Viveros, Marian N; Ren, Minghua; Mokgalaka-Matlala, Ntebogeng S; Castillo-Michel, Hiram; Gardea-Torresdey, Jorge L

    2010-10-01

    Arbuscular mycorrhizal fungi have been known to increase metal uptake in plants. In this study, mesquite (Prosopis juliflora-velutina) inoculated with Glomus deserticola or amended with EDTA were grown for 30 days in soil containing Cr(III) or Cr(VI) at 0, 40, 80, and 160 mg kg(-1). Total amylase activity (TAA) was monitored as a stress indicator. Element concentrations and distribution in tissue were determined using ICP-OES, electron scanning microprobe, and TEM. Inoculated Cr(VI) treated plants had 21% and 30% more Cr than uninoculated and EDTA treated roots, respectively, at 80 mg Cr kg(-1) treatment. In the case of Cr(III), EDTA produced the highest Cr accumulation in roots. TAA was higher in inoculated plants grown with Cr(III) at 80 and 160 mg kg(-1) and Cr(VI) at 40 and 160 mg kg(-1). The X-ray mapping showed higher metal concentrations in the vascular system of inoculated plants and the TEM micrographs demonstrated the presence of G. deserticola in roots.

  9. Rhizosphere bacteria containing 1-aminocyclopropane-1-carboxylate deaminase increase yield of plants grown in drying soil via both local and systemic hormone signalling.

    PubMed

    Belimov, Andrey A; Dodd, Ian C; Hontzeas, Nikos; Theobald, Julian C; Safronova, Vera I; Davies, William J

    2009-01-01

    Decreased soil water availability can stimulate production of the plant hormone ethylene and inhibit plant growth. Strategies aimed at decreasing stress ethylene evolution might attenuate its negative effects. An environmentally benign (nonchemical) method of modifying crop ethylene relations - soil inoculation with a natural root-associated bacterium Variovorax paradoxus 5C-2 (containing the enzyme 1-aminocyclopropane-1-carboxylate (ACC) deaminase that degrades the ethylene precursor ACC), was assessed with pea (Pisum sativum) plants grown in drying soil. Inoculation with V. paradoxus 5C-2, but not with a transposome mutant with massively decreased ACC deaminase activity, improved growth, yield and water-use efficiency of droughted peas. Systemic effects of V. paradoxus 5C-2 included an amplified soil drying-induced increase of xylem abscisic acid (ABA) concentration, but an attenuated soil drying-induced increase of xylem ACC concentration. A local bacterial effect was increased nodulation by symbiotic nitrogen-fixing bacteria, which prevented a drought-induced decrease in nodulation and seed nitrogen content. Successfully deploying a single bacterial gene in the rhizosphere increased yield and nutritive value of plants grown in drying soil, via both local and systemic hormone signalling. Such bacteria may provide an easily realized, economic means of sustaining crop yields and using irrigation water more efficiently in dryland agriculture.

  10. Effect of wheel traffic and green manure treatments on forage yield and crown rot in alfalfa (Medicago sativa)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Harvesting alfalfa (Medicago sativa) results in mechanical wheel traffic on plants, which may damage crowns and increase the opportunity for entry of pathogens causing crown rot. Developing resistance to crown rot is problematic due to the large number of pathogens involved. Incorporation of plant b...

  11. Scaling and Predicting the Geotechnical Resistance Provided by Alfalfa in Experimental Studies of Alluvial-Channel Morphology and Planform

    NASA Astrophysics Data System (ADS)

    Bankhead, N.; Simon, A.

    2008-12-01

    Several complex interactions occur between riparian vegetation and bank stability processes. Although there are both positive and negative effects of riparian vegetation on streambank stability, a link between increased vegetation density and decreased bank erosion and lateral migration rates of channels has generally been recorded. The ability of vegetation to promote increased bank stability leads to a positive feedback, in which bank stability then allows the growth and establishment of more vegetation. To study interactions between vegetation density and channel planform, past flume studies have used alfalfa sprouts (Medicago sativa), seeded over the entire floodplain in varying densities. Such studies have observed reductions in braiding intensity with increased alfalfa density. It has been assumed in these studies that the alfalfa sprouts increase the resistance of the bank material to lateral erosion. When alfalfa sprouts are scaled up they simulate mature riparian trees well. However, the geotechnical properties of alfalfa roots, and quantification of the increase in resistance provided to the banks under different densities of alfalfa have thus far been ignored. It is therefore unknown if the resistance provided by the alfalfa roots also scales well to real-world root-reinforcement values. To quantify additional bank strength, alfalfa sprouts were grown in sand and the roots tested at regular intervals to measure tensile strength. Results of tensile-strength measurements for alfalfa sprouts displayed the typical non-linear decrease of tensile strength (in MPa) with increasing root diameter. Values for the additional cohesion provided by alfalfa roots were calculated by inputting alfalfa tensile-strength and root density data to the root-reinforcement model, RipRoot, resulting in root-reinforcement values of 0 to 11.8 kPa. These values are similar to those that would be expected under field conditions. The root-cohesion values calculated for alfalfa sprouts

  12. Alfalfa carbon and nitrogen sequestration patterns and effects of temperature and precipitation in three agro-pastoral ecotones of northern China.

    PubMed

    Chang, Shujuan; Liu, Nan; Wang, Xiaoya; Zhang, Yingjun; Xie, Yue

    2012-01-01

    Alfalfa (Medicago sativa L.) is a primary and widely cultivated forage crop in China. As a perennial leguminous grass, continuous planted alfalfa may influence carbon and nitrogen sequestration in soils. We evaluated the effect of alfalfa, planted for different lengths of time, and temperature and precipitation on soil organic carbon (SOC) and total nitrogen (TN) contents, and estimated soil SOC and TN inventories from 0-60 cm in three agro-pastoral ecotones of northern China. Alfalfa SOC and TN storage patterns were significantly different with increasing soil depths between the three regions of northern China. Continuous alfalfa grassland planted had a positive effect on accumulation of both SOC and TN in the Northwest region, whereas SOC storage peaked 6-7 years after planting in the Northeast and North region. Moreover, relatively higher TN storage appeared 7 years after planting in the Northeast and North regions. This study controlled as many factors as possible, but we caution that such temporal inferences could be artifacts of site selection. The regression analysis indicated that SOC and TN accumulation was mainly dependent on temperature (≥10°C of effective total accumulated temperature) in the North region. Precipitation in the growing season was the main limiting factor for SOC storage in the Northwest region and TN accumulation in the North regions. Therefore, the different climate factors affecting SOC and TN sequestration in alfalfa occurred at a regional scale.

  13. The sky is falling II: Impact of deposition produced during the static testing of solid rocket motors on corn and alfalfa.

    PubMed

    Doucette, William J; Mendenhall, Scout; McNeill, Laurie S; Heavilin, Justin

    2014-06-01

    Tests of horizontally restrained rocket motors at the ATK facility in Promontory, Utah, USA result in the deposition of an estimated 1.5million kg of entrained soil and combustion products (mainly aluminum oxide, gaseous hydrogen chloride and water) on the surrounding area. The deposition is referred to as test fire soil (TFS). Farmers observing TFS deposited on their crops expressed concerns regarding the impact of this material. To address these concerns, we exposed corn and alfalfa to TFS collected during a September 2009 test. The impact was evaluated by comparing the growth and tissue composition of controls relative to the treatments. Exposure to TFS, containing elevated levels of chloride (1000 times) and aluminum (2 times) relative to native soils, affected the germination, growth and tissue concentrations of various elements, depending on the type and level of exposure. Germination was inhibited by high concentrations of TFS in soil, but the impact was reduced if the TFS was pre-leached with water. Biomass production was reduced in the TFS amended soils and corn grown in TFS amended soils did not develop kernels. Chloride concentrations in corn and alfalfa grown in TFS amended soils were two orders of magnitude greater than controls. TFS exposed plants contained higher concentrations of several cations, although the concentrations were well below livestock feed recommendations. Foliar applications of TFS had no impact on biomass, but some differences in the elemental composition of leaves relative to controls were observed. Washing the TFS off the leaves lessened the impact. Results indicate that the TFS deposition could have an effect, depending on the amount and growth stage of the crops, but the impact could be mitigated with rainfall or the application of additional irrigation water. The high level of chloride associated with the TFS is the main cause of the observed impacts.

  14. [Efficiency of alfalfa and reed in the phytoremediation of hydrocarbon polluted soil].

    PubMed

    Muratova, A Iu; Turkovskaia, O V; Hubner, T; Kuschk, P

    2003-01-01

    The efficacy of plants as means of decontaminating hydrocarbon-polluted soil has been studied. Ditch reed (Phragmites australis) and alfalfa (Medicago sativa) markedly intensified processes of pollutant destruction, the effect being particularly pronounced in the case of polycyclic aromatic hydrocarbons (PAHs). Comparative analysis of microflora in soils (including those devoid of plants and rhizosphere) demonstrated that, in addition to preventing the pollutant-induced decrease in the amount of heterotrophic microorganisms, the plants stimulated their development, significantly increasing the population of destructors. Effects of plants on major physiological groups of soil microorganisms under conditions of pollution were ambiguous. The rhizosphere consortium of alfalfa was less susceptible to effects of pollutants than that of reed.

  15. Performance and dietary preferences of white-tailed deer grazing chicory, birdsfoot trefoil or alfalfa in north central Alberta.

    PubMed

    Chapman, G A; Bork, E W; Donkor, N T; Hudson, R J

    2009-12-01

    Little information exists on the performance of deer on alternative forage species in northern temperate environments during summer and fall, the period of inherent maximum growth in deer. In performance and choice experiments, we compared live weight gain (g/kg(0.75)/day), absolute [kg/ha dry matter (DM)] and relative (% DM) herbage utilization, relative preference index (RPI) as well as plant community visitation of white-tailed deer grazing alfalfa (Medicago sativa), birdsfoot trefoil (Lotus corniculatus) or chicory (Cichorium intybus) in north central Alberta, Canada. Herbage phytomass and quality was also measured on the grazed pastures. Alfalfa had higher dry matter yields and crude protein concentrations than chicory and trefoil. Chicory had lower neutral detergent fiber concentrations than the other forages. Tannin concentrations were greatest in birds foot trefoil (nearly 55 g/kg DM), well above those in the other forages (<5 g/kg DM). Live weight gain was similar among deer feeding within the paddocks seeded to birds foot trefoil and chicory, and more than two times higher (p < 0.05) than deer feeding in paddocks seeded to alfalfa. Deer spent more grazing time (about 40%) on chicory pastures than on alfalfa and birds foot trefoil pastures. RPI values were greatest for birds foot trefoil at 2.11, intermediate for chicory at 1.40, and lowest for alfalfa at <0.60. Absolute herbage utilization remained similar (p > 0.05) among the three forage species. In contrast, relative herbage utilization was greater from birds foot trefoil (52% DM) than chicory (40% DM) or alfalfa (25% DM). These results suggest that the use of alfalfa with other alternative forages may prove beneficial to deer production, rather than using alfalfa pasture alone.

  16. Characterization of plant-growth-promoting effects and concurrent promotion of heavy metal accumulation in the tissues of the plants grown in the polluted soil by Burkholderia strain LD-11.

    PubMed

    Huang, Gui-Hai; Tian, Hui-Hui; Liu, Hai-Ying; Fan, Xian-Wei; Liang, Yu; Li, You-Zhi

    2013-01-01

    Plant-growth-promoting (PGP) bacteria especially with the resistance to multiple heavy metals are helpful to phytoremediation. Further development of PGP bacteria is very necessary because of the extreme diversity of plants, soils, and heavy metal pollution. A Burkholderia sp. strain, numbered LD-11, was isolated, which showed resistances to multiple heavy metals and antibiotics. It can produce indole-3-acetic acid, 1-aminocyclopropane-1-carboxylic acid deaminase and siderophores. Inoculation with the LD-11 improved germination of seeds of the investigated vegetable plants in the presence of Cu, promoted elongation of roots and hypocotyledonary axes, enhanced the dry weights of the plants grown in the soils polluted with Cu and/or Pb, and increased activity of the soil urease and the rhizobacteria diversity. Inoculation with the LD-11 significantly enhanced Cu and/or Pb accumulation especially in the roots of the plants grown in the polluted soils. Notably, LD-11 could produce siderophores in the presence of Cu. Conclusively, the PGP effects and concurrent heavy metal accumulation in the plant tissues results from combined effects of the above-mentioned multiple factors. Cu is an important element that represses production of the siderophore by the bacteria. Phytoremediation by synergistic use of the investigated plants and the bacterial strain LD-11 is a phytoextraction process.

  17. Assessing of the contributions of pod photosynthesis to carbon acquisition of seed in alfalfa (Medicago sativa L.).

    PubMed

    Zhang, Wenxu; Mao, Peisheng; Li, Yuan; Wang, Mingya; Xia, Fangshan; Wang, Hui

    2017-02-07

    The distribution of carbon from a branch setting pod in alfalfa was investigated during the seed development of seeds to determine the relative contribution of pod and leaf photoassimilates to the total C balance and to investigate the partitioning of these photoassimilates to other plant organs. A (13)Clabeling procedure was used to label C photoassimilates of pods and leaves in alfalfa, and the Δ(13)C values of a pod, leaves, a section of stem and roots were measured during seed development on day 10, 15, 20 and 25 after labeling of the pod. The results showed that the alfalfa pod had photosynthetic capacity early in the development of seeds, and that pod photosynthesis could provide carbon to alfalfa organs including seeds, pods, leaves, stems and roots, in addition to leaf photosynthesis. Photosynthesis in the pod affected the total C balance of the alfalfa branch with the redistribution of a portion of pod assimilates to other plant organs. The assimilated (13)C of the pod was used for the growth requirements of plant seeds and pods. The requirements for assimilated C came primarily from the young pod in early seed development, with later requirements provided primarily from the leaf.

  18. Assessing of the contributions of pod photosynthesis to carbon acquisition of seed in alfalfa (Medicago sativa L.)

    PubMed Central

    Zhang, Wenxu; Mao, Peisheng; Li, Yuan; Wang, Mingya; Xia, Fangshan; Wang, Hui

    2017-01-01

    The distribution of carbon from a branch setting pod in alfalfa was investigated during the seed development of seeds to determine the relative contribution of pod and leaf photoassimilates to the total C balance and to investigate the partitioning of these photoassimilates to other plant organs. A 13Clabeling procedure was used to label C photoassimilates of pods and leaves in alfalfa, and the Δ13C values of a pod, leaves, a section of stem and roots were measured during seed development on day 10, 15, 20 and 25 after labeling of the pod. The results showed that the alfalfa pod had photosynthetic capacity early in the development of seeds, and that pod photosynthesis could provide carbon to alfalfa organs including seeds, pods, leaves, stems and roots, in addition to leaf photosynthesis. Photosynthesis in the pod affected the total C balance of the alfalfa branch with the redistribution of a portion of pod assimilates to other plant organs. The assimilated 13C of the pod was used for the growth requirements of plant seeds and pods. The requirements for assimilated C came primarily from the young pod in early seed development, with later requirements provided primarily from the leaf. PMID:28169330

  19. Molybdate in Rhizobial Seed-Coat Formulations Improves the Production and Nodulation of Alfalfa

    PubMed Central

    Zhou, Jiqiong; Deng, Bo; Zhang, Yingjun; Cobb, Adam B.; Zhang, Zhao

    2017-01-01

    Rhizobia-legume symbiosis is the most well researched biological nitrogen fixation system. Coating legume seeds with rhizobia is now a recognized practical measure for improving the production of legume corp. However, the efficacy of some commercial rhizobia inoculants cannot be guaranteed in China due to the low rate of live rhizobia in these products. A greenhouse experiment was conducted to assess the effects of different rhizobial inoculant formulations on alfalfa productivity and nitrogen fixation. Two rhizobia strains, (ACCC17631 and ACCC17676), that are effective partners with alfalfa variety Zhongmu No. 1 were assessed with different concentrations of ammonium molybdate in seed-coat formulations with two different coating adhesives. Our study showed that the growth, nodulation, and nitrogen fixation ability of the plants inoculated with the ACCC17631 rhizobial strain were greatest when the ammonium molybdate application was0.2% of the formulation. An ammonium molybdate concentration of 0.1% was most beneficial to the growth of the plants inoculated with the ACCC17676 rhizobial strain. The sodium carboxymethyl cellulose and sodium alginate, used as coating adhesives, did not have a significant effect on alfalfa biomass and nitrogen fixation. However, the addition of skimmed milk to the adhesive improved nitrogenase activity. These results demonstrate that a new rhizobial seed-coat formulation benefitted alfalfa nodulation and yield. PMID:28099471

  20. Molybdate in Rhizobial Seed-Coat Formulations Improves the Production and Nodulation of Alfalfa.

    PubMed

    Zhou, Jiqiong; Deng, Bo; Zhang, Yingjun; Cobb, Adam B; Zhang, Zhao

    2017-01-01

    Rhizobia-legume symbiosis is the most well researched biological nitrogen fixation system. Coating legume seeds with rhizobia is now a recognized practical measure for improving the production of legume corp. However, the efficacy of some commercial rhizobia inoculants cannot be guaranteed in China due to the low rate of live rhizobia in these products. A greenhouse experiment was conducted to assess the effects of different rhizobial inoculant formulations on alfalfa productivity and nitrogen fixation. Two rhizobia strains, (ACCC17631 and ACCC17676), that are effective partners with alfalfa variety Zhongmu No. 1 were assessed with different concentrations of ammonium molybdate in seed-coat formulations with two different coating adhesives. Our study showed that the growth, nodulation, and nitrogen fixation ability of the plants inoculated with the ACCC17631 rhizobial strain were greatest when the ammonium molybdate application was0.2% of the formulation. An ammonium molybdate concentration of 0.1% was most beneficial to the growth of the plants inoculated with the ACCC17676 rhizobial strain. The sodium carboxymethyl cellulose and sodium alginate, used as coating adhesives, did not have a significant effect on alfalfa biomass and nitrogen fixation. However, the addition of skimmed milk to the adhesive improved nitrogenase activity. These results demonstrate that a new rhizobial seed-coat formulation benefitted alfalfa nodulation and yield.

  1. Screening of Cd tolerant genotypes and isolation of metallothionein genes in alfalfa (Medicago sativa L.).

    PubMed

    Wang, Xiaojuan; Song, Yu; Ma, Yanhua; Zhuo, Renying; Jin, Liang

    2011-12-01

    In order to evaluate Cd tolerance in wide-ranging sources of alfalfa (Medicago sativa) and to identify Cd tolerant genotypes which may potentially be useful for restoring Cd-contaminated environments, thirty-six accessions of alfalfa were screened under hydroponic culture. Our results showed that the relative root growth rate varied from 0.48 to 1.0, which indicated that different alfalfa accessions had various responses to Cd stress. The candidate fragments derived from differentially expressed metallothionein (MT) genes were cloned from leaves of two Cd tolerant genotypes, YE and LZ. DNA sequence and the deduced protein sequence showed that MsMT2a and MsMT2b had high similarity to those in leguminous plants. DDRT-PCR analysis showed that MsMT2a expressed in both YE and LZ plants under control and Cd stress treatment, but MsMT2b only expressed under Cd stress treatment. This suggested that MsMT2a was universally expressed in leaves of alfalfa but expression of MsMT2b was Cadmium (Cd) inducible.

  2. Alfalfa -- a sustainable crop for biomass energy production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alfalfa (Medicago sativa) has the potential to be a significant contributor to America's renewable energy future. In an alfalfa biomass energy production system, alfalfa forage would be separated into stem and leave fractions. The stems would be processed to produce energy, and the leaves would be s...

  3. Cash in on N credits when corn follows alfalfa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    When alfalfa is killed, some of the accumulated N in the soil and in alfalfa leaves, stems, and roots becomes available to subsequent crops. This increased N supply is known as the “alfalfa N credit,” which is the amount of fertilizer or available manure N a grower can save, resulting in higher net ...

  4. Comparative drought response in eleven diverse alfalfa accessions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alfalfa (Medicago sativa L.) production is often negatively affected by drought stress. This is particularly true for alfalfa that is cultivated on rangeland. Thus, the development of drought-tolerant alfalfa cultivars is of great significance. A greenhouse study was conducted to evaluate 11 alfa...

  5. Mentha canadensis L., a subtropical plant can withstand first few fall frost when grown in northern climate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Japanese cornmint (Mentha canadensis L.) is a subtropical essential oil crop grown in Asia and South America. The essential oil of Japanese cornmint is the only commercial source for production of natural crystalline menthol, an important aromatic agent used in various industrial applications. The ...

  6. Growth, reproductive phenology and yield responses of a potential biofuel plant, Jatropha curcas grown under projected 2050 levels of elevated CO2.

    PubMed

    Kumar, Sumit; Chaitanya, Bharatula S K; Ghatty, Sreenivas; Reddy, Attipalli R

    2014-11-01

    Jatropha (Jatropha curcas) is a non-edible oil producing plant which is being advocated as an alternative biofuel energy resource. Its ability to grow in diverse soil conditions and minimal requirements of essential agronomical inputs compared with other oilseed crops makes it viable for cost-effective advanced biofuel production. We designed a study to investigate the effects of elevated carbon dioxide concentration ([CO(2)]) (550 ppm) on the growth, reproductive development, source-sink relationships, fruit and seed yield of J. curcas. We report, for the first time that elevated CO(2) significantly influences reproductive characteristics of Jatropha and improve its fruit and seed yields. Net photosynthetic rate of Jatropha was 50% higher in plants grown in elevated CO(2) compared with field and ambient CO(2) -grown plants. The study also revealed that elevated CO(2) atmosphere significantly increased female to male flower ratio, above ground biomass and carbon sequestration potential in Jatropha (24 kg carbon per tree) after 1 year. Our data demonstrate that J. curcas was able to sustain enhanced rate of photosynthesis in elevated CO(2) conditions as it had sufficient sink strength to balance the increased biomass yields. Our study also elucidates that the economically important traits including fruit and seed yield in elevated CO(2) conditions were significantly high in J. curcas that holds great promise as a potential biofuel tree species for the future high CO(2) world.

  7. The phenotype alterations showed by the res tomato mutant disappear when the plants are grown under semi-arid conditions: Is the res mutant tolerant to multiple stresses?

    PubMed

    Garcia-Abellan, José O; Albaladejo, Irene; Egea, Isabel; Flores, Francisco B; Capel, Carmen; Capel, Juan; Angosto, Trinidad; Lozano, Rafael; Bolarin, Maria C

    2016-02-23

    The res (restored cell structure by salinity) mutant, recently identified as the first tomato mutant accumulating jasmonate (JA) without stress, exhibited important morphological alterations when plants were grown under control conditions but these disappeared under salt stress. Since the defense responses against stresses are activated in the res mutant as a consequence of the increased expression of genes from the JA biosynthetic and signaling pathways, the mutant may display a tolerance response not only to salt stress but also to multiple stresses. Here, we show that when res mutant plants are grown under the summer natural conditions of the Mediterranean area, with high temperatures and low relative humidity, the characteristic leaf chlorosis exhibited by the mutant disappears and leaves become dark green over time, with a similar aspect to WT leaves. Moreover, the mutant plants are able to achieve chlorophyll and fluorescence levels similar to those of WT. These results hint that research on res tomato mutant may allow very significant advances in the knowledge of defense responses activated by JA against multiple stresses.

  8. Detection of carbon nanotubes in plant roots through microwave-induced heating

    NASA Astrophysics Data System (ADS)

    Irin, Fahmida; Shrestha, Babina; Canas, Jaclyn; Saed, Mohammad; Green, Micah

    2012-02-01

    We demonstrate a novel technique for quantitative detection of CNTs in biological samples by utilizing the thermal response of CNTs under microwave irradiation. In particular, rapid heating of CNTs due to microwave absorption was employed to quantify the amount of CNTs present in alfalfa plant roots. Alfalfa roots were prepared by injecting a known amount of CNTs (single walled and multi walled) and exposed to 30-50 W microwave power to generate calibration curves (temperature rise vs. CNT mass). These calibration curves serve as a characterization tool to determine the unknown amount of CNTs absorbed by alfalfa plant roots grown in CNT-laden soil with superior accuracy and sensitivity. Moreover, the threshold for detectable CNT concentration is much lower than common analytical methods of detecting nanomaterials, such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectroscopy. Considering the lack of effective detection methods for CNT uptake in plants, this method is not only unique but also practical, as it addresses a major problem in the field of nanotoxicology risk assessment.

  9. The Undergraduate ALFALFA Team: Collaborative Research Projects

    NASA Astrophysics Data System (ADS)

    Cannon, John M.; Koopmann, Rebecca A.; Haynes, Martha P.; Undergraduate ALFALFA Team, ALFALFA Team

    2016-01-01

    The NSF-sponsored Undergraduate ALFALFA (Arecibo Legacy Fast ALFA) Team (UAT) has allowed faculty and students from a wide range of public and private colleges and especially those with small astronomy programs to learn how science is accomplished in a large collaboration while contributing to the scientific goals of a legacy radio astronomy survey. The UAT has achieved this through close collaboration with ALFALFA PIs to identify research areas accessible to undergraduates. In this talk we will summarize the main research efforts of the UAT, including multiwavelength followup observations of ALFALFA sources, the UAT Collaborative Groups Project, the Survey of HI in Extremely Low-mass Dwarfs (SHIELD), and the Arecibo Pisces-Perseus Supercluster Survey. This work has been supported by NSF grants AST-0724918/0902211, AST-075267/0903394, AST-0725380, and AST-1211005.

  10. Effective microorganisms enhance the scavenging capacity of the ascorbate-glutathione cycle in common bean (Phaseolus vulgaris L.) plants grown in salty soils.

    PubMed

    Talaat, Neveen B

    2014-07-01

    No information is available regarding effective microorganisms (EM) influence on the enzymatic and non-enzymatic antioxidant defence system involved in the ascorbate-glutathione cycle under saline conditions. Therefore, as a first approach, this article focuses on the contribution of EM to the scavenging capacity of the ascorbate-glutathione cycle in salt-stressed plants. It investigates some mechanisms underlying alleviation of salt toxicity by EM application. Phaseolus vulgaris cv. Nebraska plants were grown under non-saline or saline conditions (2.5 and 5.0 dSm(-1)) with and without EM application. Lipid peroxidation and H2O2 content were significantly increased in response to salinity, while they decreased with EM application in both stressed and non-stressed plants. Activities of ascorbate peroxidase (APX; EC 1.11.1.11) and glutathione reductase (GR; EC 1.6.4.2) increased under saline conditions; these increases were more significant in salt-stressed plants treated by EM. Activities of monodehydroascorbate reductase (MDHAR; EC 1.6.5.4) and dehydroascorbate reductase (DHAR; EC 1.8.5.1) decreased in response to salinity; however, they were significantly increased in stressed plants treated with EM. Ascorbate and glutathione contents were increased with the increasing salt concentration; moreover they further increased in stressed plants treated with EM. Ratios of AsA/DHA and GSH/GSSG decreased under saline conditions, whereas they were significantly increased with EM treatment in the presence or in the absence of soil salinization. The EM treatment detoxified the stress generated by salinity and significantly improved plant growth and productivity. Enhancing the H2O2-scavenging capacity of the ascorbate-glutathione cycle in EM-treated plants may be an efficient mechanism to attenuate the activation of plant defences.

  11. Strobilurin fungicides induce changes in photosynthetic gas exchange that do not improve water use efficiency of plants grown under conditions of water stress.

    PubMed

    Nason, Mark A; Farrar, John; Bartlett, David

    2007-12-01

    The effects of five strobilurin (beta-methoxyacrylate) fungicides and one triazole fungicide on the physiological parameters of well-watered or water-stressed wheat (Triticum aestivum L.), barley (Hordeum vulgare L.) and soya (Glycine max Merr.) plants were compared. Water use efficiency (WUE) (the ratio of rate of transpiration, E, to net rate of photosynthesis, A(n)) of well-watered wheat plants was improved slightly by strobilurin fungicides, but was reduced in water-stressed plants, so there is limited scope for using strobilurins to improve the water status of crops grown under conditions of drought. The different strobilurin fungicides had similar effects on plant physiology but differed in persistence and potency. When applied to whole plants using a spray gun, they reduced the conductance of water through the epidermis (stomatal and cuticular transpiration), g(sw), of leaves. Concomitantly, leaves of treated plants had a lower rate of transpiration, E, a lower intercellular carbon dioxide concentration, c(i), and a lower net rate of photosynthesis, A(n), compared with leaves of control plants or plants treated with the triazole. The mechanism for the photosynthetic effects is not known, but it is hypothesised that they are caused either by strobilurin fungicides acting directly on ATP production in guard cell mitochondria or by stomata responding to strobilurin-induced changes in mesophyll photosynthesis. The latter may be important since, for leaves of soya plants, the chlorophyll fluorescence parameter F(v)/F(m) (an indication of the potential quantum efficiency of PSII photochemistry) was reduced by strobilurin fungicides. It is likely that the response of stomata to strobilurin fungicides is complex, and further research is required to elucidate the different biochemical pathways involved.

  12. Evaluation of the metabolic fate of munitions material (TNT & RDX) in plant systems and initial assessment of material interaction with plant genetic material. Validation of the metabolic fate of munitions materials (TNT, RDX) in mature crops

    SciTech Connect

    Fellows, R.J.; Harvey, S.D.; Cataldo, D.A.

    1995-09-01

    The goals of this effort were to confirm and expand data related to the behavior and impacts of munitions residues upon human food chain components. Plant species employed included corn (Zea mays), alfalfa (Medicago sativa). spinach (Spinacea oleraceae), and carrot (Daucus carota). Plants were grown from seed to maturity (70 to 120 days) in a low-fertility soil (Burbank) amended with either {sup 14}C-TNT or {sup 14}C-RDX at which time they were harvested and analyzed for munitions uptake, partitioning, and chemical form of the munition or munition-metabolite. All four of the plant species used in this study accumulated the {sup 14}C-TNT- and RDX-derived label. The carrot, alfalfa, and corn demonstrated a higher percentage of label retained in the roots (62, 73, and 83% respectively). The spinach contained less activity in its root (36%) but also contained the highest TNT specific activity observed (>4600 jig TNT equivalents/g dry wt.). The specific uptake values of RDX for the spinach and alfalfa were comparable to those previously reported for wheat and bean (314 to 590 {mu}g RDX-equivalents/g dry wt. respectively). An exception to this may be the carrot where the specific activity was found to exceed 4200 {mu}g RDX-equivalents/g dry wt. in the shoot. The total accumulation of TNT by the plants ranged from 1.24% for the spinach to 2.34% for the carrot. The RDX plants ranging from 15% for the spinach to 37% for the carrot. There was no identifiable TNT or amino dinitrotoluene (ADNT) isomers present in the plants however, the parent RDX compound was found at significant levels in the shoot of alfalfa (> 1 80 {mu}g/g) and corn (>18 {mu}g/g).

  13. Health risk assessment of heavy metals contamination in tomato and green pepper plants grown in soils amended with phosphogypsum waste materials.

    PubMed

    Al-Hwaiti, Mohammad; Al-Khashman, Omar

    2015-04-01

    Phosphogypsum (PG) is a waste produced by the phosphate fertilizer industry that has relatively high concentrations of some heavy metals (e.g., Cd, Cr, Cu, Pb, V, and Zn). The present study was conducted to investigate heavy metal contamination in soils and vegetables (tomatoes and green peppers) and to evaluate the possible health risks associated with the consumption of vegetables grown in PG-amended soils. The enrichment factor values indicated that Pb, Cr, Cu, Ni, Zn, and V were depleted to minimally enriched, and Cd was moderately enriched. The pollution load index values indicated that the PG-amended soils were strongly polluted with Cd, moderately polluted with Cr and Ni, and slightly polluted with Pb, Cu, Zn and V. The geo-accumulation index values indicated that the PG-amended soils were uncontaminated with Pb, Cr, Cu, Ni, Zn, V, and moderately contaminated with Cd. The trace metal transfer for Cd, Cr, Pb, and Zn concentrations was below what are considered as acceptable limits (<1) for food production in soil and vegetables (tomatoes and green peppers) at each site area. Soil-to-plant transfer factor values decreased in order of Zn > Pb > Cd > Cr. The biological absorption coefficients in plants are, in order of highest to lowest, Pb > Zn > Cd > Cr, which suggests that Pb is more bioavailable to plants than Cd, Cr, and Zn. Furthermore, this study highlights that both adults and children consuming vegetables (e.g., tomatoes and green peppers) grown in PG-amended soils ingest significant amounts of the metals studied. However, the daily intake of metals (DIM) and the health risk index (HRI) values are <1, indicating a relative absence of health risks associated with the consumption of vegetables/fruits grown in PG-amended soils. However, while DIM and HRI values suggest that the consumption of plants grown in PG-amended soils is nearly free of risks, there are other sources of metal exposures such as dust inhalation, dermal contact, and ingestion (for

  14. Iodine uptake by spinach (Spinacia oleracea L.) plants grown in solution culture: effects of iodine species and solution concentrations.

    PubMed

    Zhu, Y-G; Huang, Y-Z; Hu, Y; Liu, Y-X

    2003-04-01

    A hydroponic experiment was carried out to investigate the effects of iodine species and solution concentrations on iodine uptake by spinach (Spinacia oleracea L.). Five iodine concentrations (0, 1, 10, 50 and 100 microM) for iodate (IO(3)(-)) and iodide (I(-)) were used. Results show that higher concentrations of I(-) (> or =10 microM) had some detrimental effect on plant growth, while IO(3)(-) had little effect on the biomass production of spinach plants. Increases in iodine concentration in the growth solution significantly enhanced I concentrations in plant tissues. The detrimental effect of I(-) on plant growth was probably due to the excessively high accumulation of I in plant tissues. The solution-to-spinach leaf transfer factors (TF(leaf), fresh weight basis) for plants treated with iodide were between 14.2 and 20.7 at different solution concentrations of iodide; TF(leaf) for plants treated with iodate decreased gradually from 23.7 to 2.2 with increasing solution concentrations of iodate. The distribution coefficients (DCs) of I between leaves and roots were constantly higher for plants treated with iodate than those treated with iodide. DCs for plants treated with iodide increased with increasing solution concentrations of iodide, while DCs for plants treated with iodate (around 5.5) were similar across the range of solution concentrations of iodate used in this experiment. The implications of iodine accumulation in leafy vegetables in human iodine nutrition are also discussed.

  15. Prediction of phytoavailability of trace metals to plants: Comparison between chemical extractions and soil-grown radish

    NASA Astrophysics Data System (ADS)

    Baraud, Fabienne; Leleyter, Lydia

    2012-08-01

    One of the major routes of human exposure to toxic metals is the consumption of vegetables grown on contaminated soils. Radishes were grown in three different soils (kitchen garden, agricultural and industrial soils), presenting various contamination levels. A sequential extraction procedure was compared with EDTA and HCl simple extractions methods in order to predict the metals phytoavailabilty to radish. The analysis of the results shows that the simple HCl and sequential chemical extractions bring complementary results, since HCl is correlated in the phytoavailability of Cd, Mn and Zn, whereas the sequential extraction is correlated in the phytoavailability of Cr, Fe, Mn, Ni. EDTA simple extraction brings here less interesting results than the two other tested extractions.

  16. Salt stress alters DNA methylation levels in alfalfa (Medicago spp).

    PubMed

    Al-Lawati, A; Al-Bahry, S; Victor, R; Al-Lawati, A H; Yaish, M W

    2016-02-26

    Modification of DNA methylation status is one of the mechanisms used by plants to adjust gene expression at both the transcriptional and posttranscriptional levels when plants are exposed to suboptimal conditions. Under abiotic stress, different cultivars often show heritable phenotypic variation accompanied by epigenetic polymorphisms at the DNA methylation level. This variation may provide the raw materials for plant breeding programs that aim to enhance abiotic stress tolerance, including salt tolerance. In this study, methylation-sensitive amplified polymorphism (MSAP) analysis was used to assess cytosine methylation levels in alfalfa (Medicago spp) roots exposed to increasing NaCl concentrations (0.0, 8.0, 12.0, and 20.0 dS/m). Eleven indigenous landraces were analyzed, in addition to a salt-tolerant cultivar that was used as a control. There was a slight increase in DNA methylation upon exposure to high levels of soil salinity. Phylogenetic analysis using MSAP showed epigenetic variation within and between the alfalfa landraces when exposed to saline conditions. Based on MSAP and enzyme-linked immunosorbent assay results, we found that salinity increased global DNA methylation status, particularly in plants exposed to the highest level of salinity (20 dS/m). Quantitative reverse transcription-polymerase chain reaction indicated that this might be mediated by the overexpression of methyltransferase homolog genes after exposure to saline conditions. DNA demethylation using 5-azacytidine reduced seedling lengths and dry and fresh weights, indicating a possible decrease in salinity tolerance. These results suggest that salinity affects DNA methylation flexibility.

  17. Infection of Seedlings of Alfalfa and Red Clover by Concomitant Populations of Meloidogyne incognita and Pratylenchus penetrans

    PubMed Central

    Turner, Deborah R.; Chapman, R. A.

    1972-01-01

    Invasion of 2-day-old seedlings of 'Buffalo' alfalfa and 'Kenland' red clover by larvae of M. incognita and adults of P. penetrans, during 1-3 day periods of incubation at 24 C, was investigated in 50-mm petri dishes on 1% agar. Penetration by both nematodes increased arithmetically with increased numbers in inocula. P. penetrans invaded alfalfa more readily than red cover, but M. incognita invaded red clover more readily than alfalfa. Both nematodes inhibited root-elongation of alfalfa more than that of red clover. In combinations of 10 and 50 of both nematodes, invasion of both plants by both nematodes was the same as for each nematode alone. Penetration by M. incognita into alfalfa, but not into red clover, was significantly reduced when combinations of 50 M. incognita and 200 P. penetrans were inoculated simultaneously. In the presence of large numbers of entrant P. penetrans in both plants, penetration by M. incognita was highly significantly reduced. Penetration by P. penetrans was unaffected in the reciprocal situations. PMID:19319281

  18. Co-transforming bar and CsLEA enhanced tolerance to drought and salt stress in transgenic alfalfa (Medicago sativa L.).

    PubMed

    Zhang, Jiyu; Duan, Zhen; Zhang, Daiyu; Zhang, Jianquan; Di, Hongyan; Wu, Fan; Wang, Yanrong

    2016-03-25

    Drought and high salinity are two major abiotic factors that restrict alfalfa productivity. A dehydrin protein, CsLEA, from the desert grass Cleistogenes songorica was transformed into alfalfa (Medicago sativa L.) via Agrobacterium-mediated transformation using the bar gene as a selectable marker, and the drought and salt stress tolerances of the transgenic plants were assessed. Thirty-nine of 119 transformants were positive, as screened by Basta, and further molecularly authenticated using PCR and RT-PCR. Phenotype observations revealed that the transgenic plants grew better than the wild-type (WT) plants after 15d of drought stress and 10d of salt stress: the leaves of WT alfalfa turned yellow, whereas the transgenic alfalfa leaves only wilted; after rewatering, the transgenic plants returned to a normal state, though the WT plants could not be restored. Evaluation of physiologic and biochemical indices during drought and salt stresses showed a relatively lower Na(+) content in the leaves of the transgenic plants, which would reduce toxic ion effects. In addition, the transgenic plants were able to maintain a higher relative water content (RWC), higher shoot biomass, fewer photosystem changes, decreased membrane injury, and a lower level of osmotic stress injury. These results demonstrate that overexpression of the CsLEA gene can enhance the drought and salt tolerance of transgenic alfalfa; in addition, carrying the bar gene in the genome may increase herbicide resistance.

  19. Accumulation and distribution of iron, cadmium, lead and nickel in cucumber plants grown in hydroponics containing two different chelated iron supplies.

    PubMed

    Csog, Árpád; Mihucz, Victor G; Tatár, Eniko; Fodor, Ferenc; Virág, István; Majdik, Cornelia; Záray, Gyula

    2011-07-01

    Cucumber plants grown in hydroponics containing 10 μM Cd(II), Ni(II) and Pb(II), and iron supplied as Fe(III) EDTA or Fe(III) citrate in identical concentrations, were investigated by total-reflection X-ray fluorescence spectrometry with special emphasis on the determination of iron accumulation and distribution within the different plant compartments (root, stem, cotyledon and leaves). The extent of Cd, Ni and Pb accumulation and distribution were also determined. Generally, iron and heavy-metal contaminant accumulation was higher when Fe(III) citrate was used. The accumulation of nickel and lead was higher by about 20% and 100%, respectively, if the iron supply was Fe(III) citrate. The accumulation of Cd was similar. In the case of Fe(III) citrate, the total amounts of Fe taken up were similar in the control and heavy-metal-treated plants (27-31 μmol/plant). Further, the amounts of iron transported from the root towards the shoot of the control, lead- and nickel-contaminated plants were independent of the iron(III) form. Although Fe mobility could be characterized as being low, its distribution within the shoot was not significantly affected by the heavy metals investigated.

  20. Health risk assessment of polycyclic aromatic hydrocarbons and heavy metals via dietary intake of vegetables grown in the vicinity of thermal power plants.

    PubMed

    Khillare, P S; Jyethi, Darpa Saurav; Sarkar, Sayantan

    2012-05-01

    Six different vegetables grown in the vicinity of three thermal power plants and a background site in Delhi, India were analyzed for 16 priority polycyclic aromatic hydrocarbons (PAHs) and 7 heavy metals (Cd, Cu, Cr, Ni, Zn, Fe and Mn). Annual mean concentrations of PAHs and all metals were found to be significantly higher (ANOVA, p<0.001) at power plant sites as compared to the background site. Higher abundances of coal tracer PAHs such as Phen, Anth, Flan, Pyr and Chry in power plant vegetables suggested possible impacts of coal combustion emissions. Higher ratios of polluted sample-to-background sample of vegetables were found especially for Cr, Cd, Ni and Zn. Spinach and radish showed greater accumulation of PAHs and metals on a mass basis at the power plant sites while vegetables belonging to the gourd family showed highest relative enrichment. Power plant samples showed 184-475% greater metal pollution index (MPI) values as compared to the background location while health risk indices (HRI) for Cd and Ni exceeded the safe limit for most vegetables. Incremental lifetime cancer risk (ILCR) assessment showed that up to 58 excess cancer cases are likely in Delhi for lifetime ingestion exposure to PAHs at their observed concentrations.

  1. (Carbon isotope fractionation in plants: Progress report)

    SciTech Connect

    Not Available

    1987-01-01

    The purpose of this work is to use carbon isotope fractionation as a means of studying photosynthetic efficiency in plants. During the past year we have developed a new short-term method for measuring the isotope fractionation over a period of about an hour. This method is being used to study a variety of environmental and developmental effects in both C/sub 3/ and C/sub 4/ plants, and these results are being compared with results of the traditional combustion method. We have made extensive studies of aspartic acid, malic acid, and citric acid as possible indicators of the functioning of phosphoenolpyruvate carboxylase in C/sub 3/ plants. We find that most of the aspartic acid in proteins in C/sub 3/ plants is synthesized by action of phosphoenolpyruvate carboxylase on atmospheric CO/sub 2/ and phosphoenolpyruvate produced by glycolysis. The metabolically active pool of malate, aspartate, and citrate, on the other hand, appear not to be principally synthesized by this route. Studies of C/sub 4/ plants are in progress. During deacidification, CAM plants lose CO/sub 2/ to the atmosphere, and this material is highly enriched in carbon-13. Field-grown and growth-chamber grown CAM plants show similar isotope fractionations. Ploidy effects on isotope fractionation in alfalfa are extremely small.

  2. Leaf chlorosis in oilseed rape plants (Brassica napus) grown on cadmium-polluted soil: causes and consequences for photosynthesis and growth.

    PubMed

    Baryla, A; Carrier, P; Franck, F; Coulomb, C; Sahut, C; Havaux, M

    2001-04-01

    Brassica napus L. (oilseed rape) was grown from seeds on a reconstituted soil contaminated with cadmium (100 mg Cd kg-1 dry soil), resulting in a marked chlorosis of the leaves which was investigated using a combination of biochemical, biophysical and physiological methods. Spectroscopic and chromatographic analyses of the photosynthetic pigments indicated that chlorosis was not due to a direct interaction of Cd with the chlorophyll biosynthesis pathway. In addition, mineral deficiency and oxidative stress were apparently not involved in the pigment loss. Leaf chlorosis was attributable to a marked decrease in the chloroplast density caused by a reduction in the number of chloroplasts per cell and a change in cell size, suggesting that Cd interfered with chloroplast replication and cell division. Relatively little Cd was found in the chloroplasts and the properties of the photosynthetic apparatus (electron transport, protein composition, chlorophyll antenna size, chloroplast ultrastructure) were not affected appreciably in plants grown on Cd-polluted soil. Depth profiling of photosynthetic pigments by phase-resolved photoacoustic spectroscopy revealed that the Cd-induced decrease in pigment content was very pronounced at the leaf surface (stomatal guard cells) compared to the leaf interior (mesophyll). This observation was consistent with light transmission and fluorescence microscopy analyses, which revealed that stomata density in the epidermis was noticeably reduced in Cd-exposed leaves. Concomitantly, the stomatal conductance estimated from gas-exchange measurements was strongly reduced with Cd. When plants were grown in a high-CO2 atmosphere (4,000 microliters CO2 l-1), the inhibitory effect of Cd on growth was not cancelled, suggesting that the reduced availability of CO2 at the chloroplast level associated with the low stomatal conductance was not the main component of Cd toxicity in oilseed rape.

  3. The Essential Oils of Rhaponticum carthamoides Hairy Roots and Roots of Soil-Grown Plants: Chemical Composition and Antimicrobial, Anti-Inflammatory, and Antioxidant Activities.

    PubMed

    Skała, Ewa; Rijo, Patrícia; Garcia, Catarina; Sitarek, Przemysław; Kalemba, Danuta; Toma, Monika; Szemraj, Janusz; Pytel, Dariusz; Wysokińska, Halina; Śliwiński, Tomasz

    2016-01-01

    The essential oils were isolated by hydrodistillation from the hairy roots (HR) and roots of soil-grown plants (SGR) of Rhaponticum carthamoides and were analyzed by GC-MS method. In the both essential oils 62 compounds were identified. The root essential oils showed the differences in the qualitative and quantitative composition. The sesquiterpene hydrocarbons (55-62%) dominated in both essential oils. The major compounds of HR essential oil were cyperene, 13-norcypera-1(5),11(12)-diene, and cadalene while aplotaxene, nardosina-1(10),11-diene, and dauca-4(11),8-diene dominated in SGR essential oil. Both essential oils showed antibacterial activity especially against Enterococcus faecalis (ATCC 29212) and Pseudomonas aeruginosa (ATCC 27853) (MIC value = 125 µg/mL). HR and SGR essential oils also decreased the expression of IL-1β, IL-6, and TNF-α and the ROS level in LPS-treatment astrocytes. This is the first report to describe the chemical composition of R. carthamoides essential oil from hairy roots, its protective effect against LPS-induced inflammation and ROS production in astrocytes, and its antimicrobial potential. The results show that R. carthamoides hairy roots may be a valuable source of the essential oil and may be an alternative to the roots of soil-grown plants.

  4. The Essential Oils of Rhaponticum carthamoides Hairy Roots and Roots of Soil-Grown Plants: Chemical Composition and Antimicrobial, Anti-Inflammatory, and Antioxidant Activities

    PubMed Central

    Rijo, Patrícia; Garcia, Catarina; Kalemba, Danuta; Toma, Monika; Szemraj, Janusz; Pytel, Dariusz; Śliwiński, Tomasz

    2016-01-01

    The essential oils were isolated by hydrodistillation from the hairy roots (HR) and roots of soil-grown plants (SGR) of Rhaponticum carthamoides and were analyzed by GC-MS method. In the both essential oils 62 compounds were identified. The root essential oils showed the differences in the qualitative and quantitative composition. The sesquiterpene hydrocarbons (55–62%) dominated in both essential oils. The major compounds of HR essential oil were cyperene, 13-norcypera-1(5),11(12)-diene, and cadalene while aplotaxene, nardosina-1(10),11-diene, and dauca-4(11),8-diene dominated in SGR essential oil. Both essential oils showed antibacterial activity especially against Enterococcus faecalis (ATCC 29212) and Pseudomonas aeruginosa (ATCC 27853) (MIC value = 125 µg/mL). HR and SGR essential oils also decreased the expression of IL-1β, IL-6, and TNF-α and the ROS level in LPS-treatment astrocytes. This is the first report to describe the chemical composition of R. carthamoides essential oil from hairy roots, its protective effect against LPS-induced inflammation and ROS production in astrocytes, and its antimicrobial potential. The results show that R. carthamoides hairy roots may be a valuable source of the essential oil and may be an alternative to the roots of soil-grown plants. PMID:28074117

  5. Development of simple sequence repeat markers and diversity analysis in alfalfa (Medicago sativa L.).

    PubMed

    Wang, Zan; Yan, Hongwei; Fu, Xinnian; Li, Xuehui; Gao, Hongwen

    2013-04-01

    Efficient and robust molecular markers are essential for molecular breeding in plant. Compared to dominant and bi-allelic markers, multiple alleles of simple sequence repeat (SSR) markers are particularly informative and superior in genetic linkage map and QTL mapping in autotetraploid species like alfalfa. The objective of this study was to enrich SSR markers directly from alfalfa expressed sequence tags (ESTs). A total of 12,371 alfalfa ESTs were retrieved from the National Center for Biotechnology Information. Total 774 SSR-containing ESTs were identified from 716 ESTs. On average, one SSR was found per 7.7 kb of EST sequences. Tri-nucleotide repeats (48.8 %) was the most abundant motif type, followed by di-(26.1 %), tetra-(11.5 %), penta-(9.7 %), and hexanucleotide (3.9 %). One hundred EST-SSR primer pairs were successfully designed and 29 exhibited polymorphism among 28 alfalfa accessions. The allele number per marker ranged from two to 21 with an average of 6.8. The PIC values ranged from 0.195 to 0.896 with an average of 0.608, indicating a high level of polymorphism of the EST-SSR markers. Based on the 29 EST-SSR markers, assessment of genetic diversity was conducted and found that Medicago sativa ssp. sativa was clearly different from the other subspecies. The high transferability of those EST-SSR markers was also found for relative species.

  6. Salicornia europaea L. Na⁺/H⁺ antiporter gene improves salt tolerance in transgenic alfalfa (Medicago sativa L.).

    PubMed

    Zhang, L Q; Niu, Y D; Huridu, H; Hao, J F; Qi, Z; Hasi, A

    2014-07-24

    In order to obtain a salt-tolerant perennial alfalfa (Medicago sativa L.), we transferred the halophyte Salicornia europaea L. Na(+)/H(+) antiporter gene, SeNHX1, to alfalfa by using the Agrobacterium-mediated transformation method. The transformants were confirmed by both PCR and RT-PCR analyses. Of 197 plants that were obtained after transformation, 36 were positive by PCR analysis using 2 primer pairs for the CaMV35S-SeNHX1 and SeNHX1-Nos fragments; 6 plants survived in a greenhouse. RT-PCR analysis revealed that SeNHX1 was expressed in 5 plants. The resultant transgenic alfalfa had better salt tolerance. After stress treatment for 21 days with 0.6% NaCl, the chlorophyll and MDA contents in transgenic plants were lower, but proline content and SOD, POD, and CAT activities were higher than those in wild-type plants. These results suggest that the salt tolerance of transgenic alfalfa was improved by the overexpression of the SeNHX1 gene.

  7. The effect of humic acids and their complexes with iron on the functional status of plants grown under iron deficiency

    NASA Astrophysics Data System (ADS)

    Abros'kin, D. P.; Fuentes, M.; Garcia-Mina, J. M.; Klyain, O. I.; Senik, S. V.; Volkov, D. S.; Perminova, I. V.; Kulikova, N. A.

    2016-10-01

    The effect of humic acids (HAs) and their iron complexes (Fe-HAs) on the input of the main mineral elements into wheat seedlings, as well as on the efficiency of photosynthesis and the lipid profile of plants, under iron deficiency has been studied. The input of iron from Fe-HA complexes and its predominant accumulation in roots are demonstrated. It is found that HAs increase the efficiency of photosynthesis due to enhanced electron transport in photosystem II. It is shown that the application of HAs and Fe-HAs is accompanied by an enhanced input of Zn into plants, which could increase the antioxidant status of plants under iron deficiency conditions. In addition, a pronounced increase in the content of lipids in plants is revealed, which is indicative of the effect of HAs on plant metabolism. The obtained results suggest that the positive effect of Fe-HAs and HAs on plants under iron deficiency conditions is due to a combination of factors, among which the effect of HAs on the antioxidant status of plants and the plant lipid metabolism predominates.

  8. Community structures and antagonistic activities of the bacteria associated with surface-sterilized pepper plants grown in different field soils.

    PubMed

    Kang, Sin Ae; Han, Jae Woo; Kim, Beom Seok

    2016-12-01

    Endophytic bacteria may act individually or in consortia in controlling certain plant diseases. In this study, pepper plants (Capsicum annuum L. cv. Nokkwang) were cultivated in glasshouse conditions using field soils collected from two different geographic locations, Deokso (DS) and Gwangyang (GY) in Korea. Community structure and antifungal activity of pepper endophytic bacteria were analyzed using culture-independent (PCR-DGGE) and culture-dependent (plating) methods, respectively. Dissimilarities were observed between DGGE profiles of DS and GY samples at all plant tissues. However, sequencing of the major DGGE bands revealed an enrichment of Firmicutes in the leaves of plants propagated in either soil. Similar results were observed with the culturable assays. Firmicutes dominated the isolates from both leaf samples, DS leaf (100 %) and GY leaf (83.3 %), although the genus compositions of DS leaf and GY leaf isolates were different. We assessed the antifungal activity of each isolate recovered to better understand the potential role that these endophytic bacteria may play. Of the 27 representative isolates from DS plant samples, 17 isolates (63.0 %) had antagonistic activity against at least one of the fungi tested. Seventeen isolates from GY plant samples (58.6 %) displayed antagonistic properties. The results show that the endophytic communities differ in the same plant species when propagated in different soils. Exploring the internal tissues of plants growing in diverse soil environments could be a way to find potential candidates for biocontrol agents.

  9. Soil sulfur amendments suppress selenium uptake by alfalfa and Western wheatgrass.

    PubMed

    Mackowiak, C L; Amacher, M C

    2008-01-01

    Selenium (Se) is a potential soil contaminant in many parts of the world where it can pose a health risk to livestock and wildlife. Phosphate ore mining in Southeast Idaho has resulted in numerous waste rock dumps revegetated with forages to stabilize the dumps and support grazing. Alfalfa (Medicago sativa L.), smooth brome (Bromus inermis Leyss.), and western wheat grass [Pascopyrum smithii (Rydb.) A. Löve] are the dominant forage species on these lands. To demonstrate the feasibility of using sulfur (S) as a soil amendment to restrict plant Se uptake, 3 kg pots containing 50:50 w/w soil and waste shale were uniformly mixed with 0, 0.5, 1.0, or 2.0 Mg ha(-1) S as either elemental S or gypsum. Pots were seeded with alfalfa or western wheat grass. Dry mass and tissue Se were monitored over several clippings. Soils were sampled at the conclusion of the study and analyzed for water-soluble, oxalate-extractable, and total Se. Sulfur amendments as either elemental S or gypsum at 1.0 Mg ha(-1) or greater equally suppressed Se uptake over 60% in both forage species. Alfalfa accumulated more Se than western wheat grass. Plant removal via successive clippings resulted in lower tissue Se accumulation over time than the use of S soil amendments alone. Alfalfa-planted soils contained lower water-soluble and oxalate-extractable Se than did the non-planted controls while western wheat grass-planted soils contained lower water-soluble Se. Applying S to these shale-based soils may be an economically viable option for treating Se-impacted, revegetated lands.

  10. Yield and forage quality of glandular-haired alfalfa under alfalfa weevil (Coleoptera: Curculionidae) and potato leafhopper (Hemiptera: Cicadellidae) pest pressure in Virginia.

    PubMed

    Dellinger, Theresa A; Youngman, Roger R; Laub, Curt A; Brewster, Carlyle C; Kuhar, Thomas P

    2006-08-01

    Cultivars of glandular-haired alfalfa, Medicago sativa L., such as '54H69', are currently available and marketed as being resistant to potato leafhopper, Empoasca fabae (Harris) (Hemiptera: Cicadellidae). 54H69 and a standard, nonglandular-haired alfalfa 'Choice' were evaluated at two locations in Virginia over a 3-yr period. Dry matter yields and concentrations of crude protein and acid detergent fiber were compared at the first, second, and third harvests. Overall, the two cultivars produced similar dry matter yields of comparable forage quality in the absence of insecticides at both locations in each year. Untreated 54H69 did not produce greater dry matter yields than untreated Choice under either light or heavier potato leafhopper pest pressure. Concentrations of crude protein did not vary between the two cultivars at any harvest. Some differences in concentrations of acid detergent fiber were detected between cultivars, but these differences were not consistent among years, harvests, or between locations. Further comparisons between untreated 54H69 and treated Choice were made, but few significant differences were detected in dry matter yields or forage quality. An economic analysis for the study indicated that a grower planting 54H69 would realize less net revenue than a grower planting Choice, largely because of the seed premium for the glandular-haired cultivar and the evident need to treat 54H69 with insecticide for control of alfalfa weevil, Hypera postica (Gyllenhal) (Coleoptera: Curculionidae), and potato leafhopper.

  11. Association of AFLP and SCAR markers with common leafspot resistance in autotetraploid alfalfa (Medicago sativa).

    PubMed

    Wang, Y; Bi, B; Yuan, Q H; Li, X L; Gao, J M

    2012-03-14

    To identify amplified fragment length polymorphism (AFLP) markers associated with resistance or susceptibility of alfalfa to common leafspot (CLS) caused by the fungus Pseudopeziza medicaginis (Dermateaceae), bulked segregant analysis was conducted based on an F(1(M × M)) population of 93 plants and a BC(1)S population of 91 plants. Three AFLP markers, ACTCAA(R206), TAGCAC(R185), and GGACTA(S264), were found to be associated with CLS resistance or susceptibility. All three markers were found at significantly different frequencies (71.9, 80.3 and 91.8%) compared to resistant or susceptible plants in the original population. Subsequently, these three AFLP markers were converted into three SCAR markers, ACTCAA(R136), TAGCAC(R128) and GGACTA(S254), which are easier to employ in breeding programs. The three SCAR markers were used in a randomly selected population with 50% resistance; the probability of finding one resistant plant was increased to 67.3, 66.7 and 90.0% with markers ACTCAA(R136), TAGCAC(R128) and GGACTA(S254), independently. If two of the SCAR markers were used simultaneously, the probability would be higher than 89%. The three SCAR markers identified in this study would be applicable for selection for CLS resistance in alfalfa breeding programs. Moreover, the genetic analysis indicated that CLS resistance in alfalfa is conferred by a single dominant gene.

  12. Sativa by falcata alfalfa hybrid variety trials

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous research has demonstrated that alfalfa (Medicago sativa L.) subsp. sativa by subsp. falcata hybrids showed heterosis. Limited work has been done examining these hybrids in a sward situation. The objective of this study was to produce sativa by falcata hybrids using Dairyland Seed Company’...

  13. Effects of silo type on ensiling alfalfa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Various silo types are used on dairy farms, but there is uncertainty as to how silo type affects losses and silage quality. The objective of this study was to compare three silo types, filled with alfalfa from the same fields and emptied simultaneously, relative to filling rates, dry matter (DM) los...

  14. Overexpression of GsZFP1 enhances salt and drought tolerance in transgenic alfalfa (Medicago sativa L.).

    PubMed

    Tang, Lili; Cai, Hua; Ji, Wei; Luo, Xiao; Wang, Zhenyu; Wu, Jing; Wang, Xuedong; Cui, Lin; Wang, Yang; Zhu, Yanming; Bai, Xi

    2013-10-01

    GsZFP1 encodes a Cys2/His2-type zinc-finger protein. In our previous study, when GsZFP1 was heterologously expressed in Arabidopsis, the transgenic Arabidopsis plants exhibited enhanced drought and cold tolerance. However, it is still unknown whether GsZFP1 is also involved in salt stress. GsZFP1 is from the wild legume Glycine soja. Therefore, the aims of this study were to further elucidate the functions of the GsZFP1 gene under salt and drought stress in the forage legume alfalfa and to investigate its biochemical and physiological functions under these stress conditions. Our data showed that overexpression of GsZFP1 in alfalfa resulted in enhanced salt tolerance. Under high salinity stress, greater relative membrane permeability and malondialdehyde (MDA) content were observed and more free proline and soluble sugars accumulated in transgenic alfalfa than in the wild-type (WT) plants; in addition, the transgenic lines accumulated less Na(+) and more K(+) in both the shoots and roots. Overexpression of GsZFP1 also enhanced the drought tolerance of alfalfa. The fold-inductions of stress-responsive marker gene expression, including MtCOR47, MtRAB18, MtP5CS, and MtRD2, were greater in transgenic alfalfa than those of WT under drought stress conditions. In conclusion, the transgenic alfalfa plants generated in this study could be used for farming in salt-affected as well as arid and semi-arid areas.

  15. Effect of 1-naphthaleneacetic acid on organic acid exudation by the roots of white lupin plants grown under phosphorus-deficient conditions.

    PubMed

    Gómez, Diego A; Carpena, Ramón O

    2014-09-15

    The effect of NAA (1-naphthaleneacetic acid) on organic acid exudation in white lupin plants grown under phosphorus deficiency was investigated. Plants were sampled periodically for collecting of organic acids (citrate, malate, succinate), and also were used to study the effect on proton extrusion and release of Na(+), K(+), Ca(2+) and Mg(2+). The tissues were later processed to quantify the organic acids in tissues, the phosphorus content and the effects on plant biomass. The exogenous addition of NAA led to an increase in organic acid exudation, but this response was not proportional to the concentration of the dose applied, noticing the largest increments with NAA 10(-8)M. In contrast the increase in root weight was proportional to the dose applied, which shows that with higher doses the roots produced are not of proteoid type. Proton extrusion and the release of cations were related to the NAA dose, the first was proportional to the dose applied and the second inversely proportional. Regarding the analysis of tissues, the results of citrate and phosphorus content in shoots show that the overall status of these parts are the main responsible of the organic acids exuded. NAA served as an enhancer of the organic acid exudation that occurs under phosphorus deficient conditions, with a response that depends on the dose applied, not only in its magnitude, but also in the mechanism of action of the plant hormone.

  16. Phytoextraction of trace elements and physiological changes in Indian mustard plants (Brassica nigra L.) grown in post methanated distillery effluent (PMDE) irrigated soil.

    PubMed

    Bharagava, R N; Chandra, R; Rai, V

    2008-11-01

    The metal accumulation potential and its physiological effects in Indian mustard plants (Brassica nigra L.) grown in soil irrigated with post methanated distillery effluent (25%, 50%, 75%, 100%, v/v) were studied after 30, 60 and 90 days after sowing. An increase in the chlorophyll and protein contents was recorded at the lower concentrations of post methanated distillery effluent (PMDE) at initial exposure periods followed by a decrease at higher concentrations of PMDE compared to their respective controls. An enhanced lipid peroxidation in tested plants was observed, which was evidenced by the increased malondialdehyde content in shoot, leaves and seeds at all the concentrations of PMDE and exposure periods compared to their respective controls. This study revealed that Indian mustard plants (B. nigra L.) are well adopted to tolerate and accumulate high quantities of trace elements due to increased level of antioxidants (cysteine and ascorbic acid) in root, shoot and leaves of the treated plants at all the concentrations and exposure periods except at 90 days, whereas a decrease was observed at 100% PMDE as compared to their respective controls.

  17. Comparative Analysis Of {sup 226}Ra Soil-To-Plant Transfer In Cabbage Grown In Various Regions

    SciTech Connect

    Madruga, M. J.; Carvalho, F. P.; Silva, L.; Gouveia, J.

    2008-08-07

    The transfer of {sup 226}Ra from soil to cabbage was compared amongst regions, namely the surroundings of Urgeirica uranium milling tailings (GE), regions with past uranium mining activities (GN1), and regions with no uranium mining activities and no uranium deposits (GN2). Results show a slight increase of the concentration ratio values at low radium concentration in soils. Statistical analysis of the mean {sup 226}Ra activity concentrations in soil and cabbage for the three regions was carried out. The comparison of {sup 226}Ra activity concentrations in soils indicated no difference (p>0.05), between GE and GN2 and significant differences (p<0.05) between GE and GN1 and between GN1 and GN2. Similar statistical results were obtained for {sup 226}Ra activity concentrations in cabbage from the same regions. It was concluded that radium Concentration Ratio (CR) for cabbage grown in the region of the main uranium milling site (GE) is of the same order of magnitude of CR in cabagge grown in background regions (GN2). However, {sup 226}Ra CR was higher in cabagge from the region with past uranium mining activities (GN1)

  18. Soil and water warming accelerates phenology and down-regulation of leaf photosynthesis of rice plants grown under free-air CO2 enrichment (FACE).

    PubMed

    Adachi, Minaco; Hasegawa, Toshihiro; Fukayama, Hiroshi; Tokida, Takeshi; Sakai, Hidemitsu; Matsunami, Toshinori; Nakamura, Hirofumi; Sameshima, Ryoji; Okada, Masumi

    2014-02-01

    To enable prediction of future rice production in a changing climate, we need to understand the interactive effects of temperature and elevated [CO2] (E[CO2]). We therefore examined if the effect of E[CO2] on the light-saturated leaf photosynthetic rate (Asat) was affected by soil and water temperature (NT, normal; ET, elevated) under open-field conditions at the rice free-air CO2 enrichment (FACE) facility in Shizukuishi, Japan, in 2007 and 2008. Season-long E[CO2] (+200 µmol mol(-1)) increased Asat by 26%, when averaged over two years, temperature regimes and growth stages. The effect of ET (+2°C) on Asat was not significant at active tillering and heading, but became negative and significant at mid-grain filling; Asat in E[CO2]-ET was higher than in ambient [CO2] (A[CO2])-NT by only 4%. Photosynthetic down-regulation at E[CO2] also became apparent at mid-grain filling; Asat compared at the same [CO2] in the leaf cuvette was significantly lower in plants grown in E[CO2] than in those grown in A[CO2]. The additive effects of E[CO2] and ET decreased Asat by 23% compared with that of A[CO2]-NT plants. Although total crop nitrogen (N) uptake was increased by ET, N allocation to the leaves and to Rubisco was reduced under ET and E[CO2] at mid-grain filling, which resulted in a significant decrease (32%) in the maximum rate of ribulose-1,5-bisphosphate carboxylation on a leaf area basis. Because the change in N allocation was associated with the accelerated phenology in E[CO2]-ET plants, we conclude that soil and water warming accelerates photosynthetic down-regulation at E[CO2].

  19. ECOLOGICAL RISK ASSESSMENT OF ALFALFA (MEDICAGO VARIA L.) GENETICLALY ENGINEERED TO EXPRESS A HUMAN METALLOTHIONEIN (HMT) GENE

    EPA Science Inventory

    The objectives of these studies were two-fold: (1) to determine efficacy of low and high expression hMT gene constructs by assessing accumulation of Cu in shoots of parental and transgenic plants of alfalfa (Medicago varia L.) exposed to different concentrations of CuSO4 by addit...

  20. Identification of molecular markers associated with Verticillium wilt resistance in alfalfa (Medicago sativa L.) using high-resolution melting.

    PubMed

    Zhang, Tiejun; Yu, Long-Xi; McCord, Per; Miller, David; Bhamidimarri, Suresh; Johnson, David; Monteros, Maria J; Ho, Julie; Reisen, Peter; Samac, Deborah A

    2014-01-01

    Verticillium wilt, caused by the soilborne fungus, Verticillium alfalfae, is one of the most serious diseases of alfalfa (Medicago sativa L.) worldwide. To identify loci associated with resistance to Verticillium wilt, a bulk segregant analysis was conducted in susceptible or resistant pools constructed from 13 synthetic alfalfa populations, followed by association mapping in two F1 populations consisted of 352 individuals. Simple sequence repeat (SSR) and single nucleotide polymorphism (SNP) markers were used for genotyping. Phenotyping was done by manual inoculation of the pathogen to replicated cloned plants of each individual and disease severity was scored using a standard scale. Marker-trait association was analyzed by TASSEL. Seventeen SNP markers significantly associated with Verticillium wilt resistance were identified and they were located on chromosomes 1, 2, 4, 7 and 8. SNP markers identified on chromosomes 2, 4 and 7 co-locate with regions of Verticillium wilt resistance loci reported in M. truncatula. Additional markers identified on chromosomes 1 and 8 located the regions where no Verticillium resistance locus has been reported. This study highlights the value of SNP genotyping by high resolution melting to identify the disease resistance loci in tetraploid alfalfa. With further validation, the markers identified in this study could be used for improving resistance to Verticillium wilt in alfalfa breeding programs.

  1. Nitrogen, Phosphor, and Potassium Level in Soil and Oil Palm Tree at various Composition of plant species mixtures grown

    NASA Astrophysics Data System (ADS)

    Hanum, C.; Rauf, A.; Fazrin, D. A.; Habibi, A. R.

    2016-08-01

    In productive oil palm plantation areas, poor vegetation is generally caused by low light intensity. This condition causes excessive erosion and decreases soil fertility. One of the efforts for soil and water conservation at oil palm plantations is through increased vegetation diversity. The changes of soil and plant nitrogen, phosporus, and potassium content, observed by planting two types of herbs under oil palm tree, with different compositions. Vegetation composition was set as: Arachis glabrata 100%; Stenotaprum secundatum 100%; Arachis glabrata 50% + Stenotaprum secundatum 50%; Arachis glabrata 75% + Stenotaprum secundatum 25%; Arachis glabrata 25% + Stenotaprum secundatum 75%. The shoot and root fresh/dry weight, nutrient content (nitrogen, phosphor, and potassium) of each cutting were measured at the end of the experiment. Ten of treatment plant were harvested and divided shoots and roots after washing out of soil. Biomass samples were dried at 70 °C for 48 h and weighed. The total N and its proportional concentration (N%) were analyzed with the micro- Kjeldahl method. Potasium analyzing with flamephotometry, and phosphor and from samples was determined by analyzing with spectrophotometry method. The results showed the highest shoot growth of A.glabarata if planting was mixed with S. secundatum, but the result was different with S.secundatum being superior if planted with monoculture system. Combination of interrow cultivation is more recommended for soil conservation and nutrient maintenance in palm oil trees were A. Glabarata 75% + S.secundatum 25%.

  2. Mercury uptake and distribution in Lavandula stoechas plants grown in soil from Almadén mining district (Spain).

    PubMed

    Sierra, M J; Millán, R; Esteban, E

    2009-11-01

    This work studies mercury root uptake by Lavandula stoechas var. Kew Red (lavender) and the distribution of this metal through the plant under greenhouse conditions along three consecutive seasons. Mercury concentration in plant tissues and in the different products obtained from lavender plants (essential oil, toilet water and in lavender tea) was assessed in order to evaluate the possible cultivation of lavender as a profitable alternative land use to mercury mining in the Almadén area once the mine had been closed down. Mercury concentration in useful parts of the plant was low (0.03-0.55 mg kg(-1)). Likewise, the essential oil, toilet water and tea obtained from these plants presented very low mercury levels, below the detection limit of the used equipment (<0.5 microg kg(-1)). In the case of the obtained tea, according to the recommendations given by the World Health Organization, the maximum daily intake of it without intoxication risk would be 85.2l. So, although other sources of mercury intake should also be considered in order to elaborate a complete toxicological risk assessment. Lavender data, obtained under this greenhouse working conditions, shows that lavender cultivation could be an alternative crop in the Almadén area.

  3. Growth and elemental accumulation of plants grown in acidic soil amended with coal fly ash-sewage sludge co-compost.

    PubMed

    Wong, Jonathan W C; Selvam, Ammaiyappan

    2009-10-01

    A greenhouse experiment was conducted to evaluate the growth and heavy-metal accumulation of Brassica chinensis and Agropyron elongatum in 10 and 25% ash-sludge co-compost (ASC)--amended loamy acidic soil (pH 4.51) at two different application rates: 20% and 40% (v/v). Soil pH increased, whereas electrical conductivity decreased with the amendment of ASC to soil. Bioavailable Cu, Zn, and Mn contents of ASC-amended soil decreased, whereas Ni, Pb, and B contents increased. Concentrations of bioavailable Cu, Zn, and Mn in sludge compost (SC)-amended soils were 5.57, 20.8, and 8.19 mg kg(-1), respectively. These concentrations were significantly lower than those in soil receiving an application rate of 20 or 25% ASC as 2.64, 8.48, and 5.26 mg kg(-1), respectively. Heavy metals and B contents of the composting mass significantly increased with an increase in ASC application rate from 20 to 40% (6.2 to 16.6 mg kg(-1) for 10% ASC- and 9.4 to 18.6 mg kg(-1) for 25% ASC-amended soil. However, when the ash content in co-compost increased from 10 to 25% during composting, bioavailable heavy-metal contents decreased. However, B contents increased with an increase in ash content. Addition of co-composts increased the dry-weight yield of the plants, and this increase was more obvious as the ash amendment rate in the co-composts and the ASC application rate increased. In case of B. chinensis, the biomass of 2.84 g/plant for 40% application of 25% ASC was significantly higher than SC (0.352 g/plant), which was 40% application of 10% ASC (0.434 g/plant) treatments. However, in A. elongatum, the differences between biomass of plants grown with 10% (1.34-1.94 g/ plant) and 25% ASC (2.12-2.21 g/plant) were not significantly different. Furthermore, there were fewer plant-available heavy metals in 25% ASC, which decreased the uptake of heavy metals by plants. ASC was favorable in increasing the growth of B. chinensis and A. elongatum. The optimal ash amendment to the sludge composting

  4. Influence of salicylic acid on rubisco and rubisco activase in tobacco plant grown under sodium chloride in vitro

    PubMed Central

    Lee, So Young; Damodaran, Puthanveettil Narayanankutty; Roh, Kwang Soo

    2014-01-01

    The present study was designed to evaluate the influence of salicylic acid (SA) on the growth of salt stress (sodium chloride) induced in tobacco plants. In addition, quantification of rubisco and rubisco activase contents of the plants was also determined in treatments with the control, 10−4 mM SA, 50 mM NaCl, 100 mM NaCl, 150 mM NaCl, SA + 50 mM NaCl, SA + 100 mM NaCl and SA + 150 mM NaCl, respectively after in vitro culture for 5 weeks. The growth of the tobacco plant decreased in 50 mM and 100 mM NaCl when not treated with SA. However, the growth was accelerated by SA, and the growth retardation caused by NaCl was improved by SA. The content of rubisco was improved by SA only in plants treated with 50 mM NaCl, and the activity of rubisco was increased by SA resulting in the decreased effect of NaCl, but only in 50 mM NaCl treated plants. The content of rubisco activase decreased due to NaCl, and SA did not improve the effect caused by NaCl. The activity of rubisco activase was increased by SA resulting in decreased activity caused by NaCl, but increased effect by SA was not recovered to the level of NaCl untreated plants. The activity of rubisco and rubisco activase, which decreased due to denaturing agents, did not demonstrate significant improvement when compared to the control. PMID:25313276

  5. Effect of metal tolerant plant growth promoting bacteria on growth and metal accumulation in Zea mays plants grown in fly ash amended soil.

    PubMed

    Kumar, Kalpna V; Patra, D D

    2013-01-01

    The present study was undertaken to examine the effect of the application of fly ash (FA) into Garden soil (GS), with and without inoculation of plant growth promoting bacteria (PGPB), on the growth and metal uptake by Zea mays plants. Three FA tolerant PGPB strains, Pseudomonas sp. PS5, PS14, and Bacillus sp. BC29 were isolated from FA contaminated soils and assessed for their plant growth promoting features on the Z. mays plants. All three strains were also examined for their ability to solubilize phosphate and to produce Indole Acetic Acid (IAA), siderophores, and hydrogencynide acid (HCN) production. Although inoculation of all strains significantly enhanced the growth of plants at both the concentration of FA but maximum growth was observed in plants inoculated with BC29 and PS14 at low level (25%) of FA concentration. The experimental results explored the plant growth promoting features of selected strains which not only enhanced growth and biomass of plants but also protected them from toxicity of FA.

  6. Phytochelatin Synthesis Promotes Leaf Zn Accumulation of Arabidopsis thaliana Plants Grown in Soil with Adequate Zn Supply and is Essential for Survival on Zn-Contaminated Soil.

    PubMed

    Kühnlenz, Tanja; Hofmann, Christian; Uraguchi, Shimpei; Schmidt, Holger; Schempp, Stefanie; Weber, Michael; Lahner, Brett; Salt, David E; Clemens, Stephan

    2016-11-01

    Phytochelatin (PC) synthesis is essential for the detoxification of non-essential metals such as cadmium (Cd). In vitro experiments with Arabidopsis thaliana seedlings had indicated a contribution to zinc (Zn) tolerance as well. We addressed the physiological role of PC synthesis in Zn homeostasis of plants under more natural conditions. Growth responses, PC accumulation and leaf ionomes of wild-type and AtPCS1 mutant plants cultivated in different soils representing adequate Zn supply, Zn deficiency and Zn excess were analyzed. Growth on Zn-contaminated soil triggers PC synthesis and is strongly impaired in PC-deficient mutants. In fact, the contribution of AtPCS1 to tolerating Zn excess is comparable with that of the major Zn tolerance factor MTP1. For plants supplied with a normal level of Zn, a significant reduction in leaf Zn accumulation of AtPCS1 mutants was detected. In contrast, AtPCS1 mutants grown under Zn-limited conditions showed wild-type levels of Zn accumulation, suggesting the operation of distinct Zn translocation pathways. Contrasting phenotypes of the tested AtPCS1 mutant alleles upon growth in Zn- or Cd-contaminated soil indicated differential activation of PC synthesis by these metals. Experiments with truncated versions identified a part of the AtPCS1 protein required for the activation by Zn but not by Cd.

  7. Genetic Structure and Molecular Variability Analysis of Citrus sudden death-associated virus Isolates from Infected Plants Grown in Brazil

    PubMed Central

    Matsumura, Emilyn Emy; Coletta Filho, Helvécio Della; de Oliveira Dorta, Silvia; Nouri, Shahideh; Machado, Marcos Antonio

    2016-01-01

    Citrus sudden death-associated virus (CSDaV) is a monopartite positive-sense single-stranded RNA virus that was suggested to be associated with citrus sudden death (CSD) disease in Brazil. Here, we report the first study of the genetic structure and molecular variability among 31 CSDaV isolates collected from both symptomatic and asymptomatic trees in CSD-affected areas. Analyses of partial nucleotide sequences of five domains of the CSDaV genomic RNA, including those encoding for the methyltransferase, the multi-domain region (MDR), the helicase, the RNA-dependent RNA polymerase and the coat protein, showed that the MDR coding region was the most diverse region assessed here, and a possible association between this region and virus adaption to different host or plant tissues is considered. Overall, the nucleotide diversity (π) was low for CSDaV isolates, but the phylogenetic analyses revealed the predominance of two main groups, one of which showed a higher association with CSD-symptomatic plants. Isolates obtained from CSD-symptomatic plants, compared to those obtained from asymptomatic plants, showed higher nucleotide diversity, nonsynonymous and synonymous substitution rates and number of amino acid changes on the coding regions located closer to the 5’ end region of the genomic RNA. This work provides new insights into the genetic diversity of the CSDaV, giving support for further epidemiological studies. PMID:27999249

  8. Plant density and N fertilizer rate on yield and nutrient content of onion developed from greenhouse grown transplants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Onions (Allium cepa L.) can be established from seed or transplants. The latter planting material can be dormant or actively growing when transplanted to the field. Onion transplants can be produced in a greenhouse, but additional information is needed regarding the cultural requirements for these...

  9. Reduced stomatal conductance in plants grown under elevated carbon dioxide leads to lower emission of herbivore induced volatiles.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Terpene volatiles produced by sweet corn (Zea Mays) upon infestation with pests such as Beet armyworm (Spodoptera exigua) function as part of an indirect plant defense mechanism by attracting parasitoid wasps. To investigate the effect of climate change on this indirect defense, we determined the im...

  10. Biological effects and biochemical studies of tomato plants grown from seeds exposed for a long time at the MIR station

    NASA Astrophysics Data System (ADS)

    Nechitailo, G.; Yurov, S.; Kuznetsov, A.; Kapitanov, A.

    Experiments at orbital space stations were carried out with seeds of various plants -- welsh onion arabidopsis wheat pea maize barley tomato etc The results of these experiments showed some discrepancy concerning germinating capacity presence of chromosome aberrations and other parameters After short-term space flights most of plants did not exhibit any irreversible changes But prolongation of space flights to over one year leads to practically complete loss of the germinating capacity in for example Arabidopsis thaliana and Crepis capillaries The level of recessive mutations increased more than 3-fold as compared to the control variants after exposure of seeds during 840 days The objects studied in the experiments described here are tomato plants obtained from seeds carried for 6 years at the station MIR According to the results of the experiments the germinating capacity of the seeds was 32 versus 60 in the control The germination of the seeds began only on the 14-15 th days in the control -- on the 5 th day In the process of ontogenesis the level of mutations revealed in the experimental variants made up to 18 as compared to the 8 in the control After 6 years of exposure under space flight conditions practically all seeds lost their germinating capacity Most viable were seeds of wheat and tomato Biochemical analysis of tomato plants of the second generation produced from seeds exposed for a long time under space flight conditions was carried out The results of the analysis demonstrated an increased

  11. Transcript analysis in two alfalfa salt tolerance selected breeding populations relative to a non-tolerant population.

    PubMed

    Gruber, M Y; Xia, J; Yu, M; Steppuhn, H; Wall, K; Messer, D; Sharpe, A G; Acharya, S N; Wishart, D S; Johnson, D; Miller, D R; Taheri, A

    2017-02-01

    With the growing limitations on arable land, alfalfa (a widely cultivated, low-input forage) is now being selected to extend cultivation into saline lands for low-cost biofeedstock purposes. Here, minerals and transcriptome profiles were compared between two new salinity-tolerant North American alfalfa breeding populations and a more salinity-sensitive western Canadian alfalfa population grown under hydroponic saline conditions. All three populations accumulated two-fold higher sodium in roots than shoots as a function of increased electrical conductivity. At least 50% of differentially expressed genes (p < 0.05) were down-regulated in the salt-sensitive population growing under high salinity, while expression remained unchanged in the saline-tolerant populations. In particular, most reduction in transcript levels in the salt-sensitive population was observed in genes specifying cell wall structural components, lipids, secondary metabolism, auxin and ethylene hormones, development, transport, signalling, heat shock, proteolysis, pathogenesis-response, abiotic stress, RNA processing, and protein metabolism. Transcript diversity for transcription factors, protein modification, and protein degradation genes was also more strongly affected in salt-tolerant CW064027 than in salt-tolerant Bridgeview and salt-sensitive Rangelander, while both saline-tolerant populations showed more substantial up-regulation in redox-related genes and B-ZIP transcripts. The report highlights the first use of bulked genotypes as replicated samples to compare the transcriptomes of obligate out-cross breeding populations in alfalfa.

  12. Hazardous impact and translocation of vanadium (V) species from soil to different vegetables and grasses grown in the vicinity of thermal power plant.

    PubMed

    Khan, Sumaira; Kazi, Tasneem Gul; Kolachi, Nida Fatima; Baig, Jameel Ahmed; Afridi, Hassan Imran; Shah, Abdul Qadir; Kumar, Sham; Shah, Faheem

    2011-06-15

    The distribution of vanadium (V) species in soil (test soil), vegetables and grasses, collected from the vicinity of a thermal power plant has been studied. For comparison purpose soil (control soil), same vegetable and grass samples were collected from agricultural land devoid of any industrial area. A simple and efficient ultrasonic assisted extraction method has been developed for the extraction of V(5+) species from soil, vegetable and grass samples using Na(2)CO(3) in the range of 0.1-0.5 mol/L. For comparison purpose same sub samples were also extracted by conventional heating method. The total and V species were determined by electrothermal atomic absorption spectrometry using different modifiers. The validity of V(5+) and V(4+) determination had been confirmed by the spike recovery and total amount of V by the analysis of CRM 1570 (spinach leave) and sub samples of agricultural soil. The concentration of total V was found in the range of 90-215 and 11.4-42.3 μg/g in test and control soil samples, respectively. The contents of V(5+) and total V in vegetables and grasses grown around the thermal power plant were found in the range of 2.9-5.25 and 8.74-14.9 μg/g, respectively, which were significantly higher than those values obtained from vegetables and fodders grown in non exposed agricultural site (P<0.01). Statistical evaluations indicate that the sum of concentrations of V(5+) and V(4+) species was not significantly different from total concentration of V in same sub samples of vegetable, grass and soil of both origins, at 95% level of confidence.

  13. Effect of a Sinorhizobium meliloti Strain with a Modified putA Gene on the Rhizosphere Microbial Community of Alfalfa

    PubMed Central

    van Dillewijn, Pieter; Villadas, Pablo J.; Toro, Nicolás

    2002-01-01

    The success of a rhizobial inoculant in the soil depends to a large extent on its capacity to compete against indigenous strains. M403, a Sinorhizobium meliloti strain with enhanced competitiveness for nodule occupancy, was recently constructed by introducing a plasmid containing an extra copy of a modified putA (proline dehydrogenase) gene. This strain and M401, a control strain carrying the same plasmid without the modified gene, were used as soil inoculants for alfalfa in a contained field release experiment at León, Spain. In this study, we determined the effects of these two strains on the indigenous microbial community. 16S rRNA genes were obtained from the rhizosphere of alfalfa inoculated with strain M403 or strain M401 or from noninoculated plants by amplification of DNA from soil with bacterial group-specific primers. These genes were analyzed and compared by restriction fragment length polymorphism and temperature gradient gel electrophoresis. The results allowed us to differentiate between alterations in the microbial community apparently caused by inoculation and by the rhizosphere effect and seasonal fluctuations induced by the alfalfa plants and by the environment. Only moderate inoculation-dependent effects could be detected, while the alfalfa plants appeared to have a much stronger influence on the microbial community. PMID:12200266

  14. Distribution pathways of hexachlorocyclohexane isomers in a soil-plant-air system. A case study with Cynara scolymus L. and Erica sp. plants grown in a contaminated site.

    PubMed

    Pereira, R Calvelo; Monterroso, C; Macías, F; Camps-Arbestain, M

    2008-09-01

    This study focuses on the main routes of distribution and accumulation of different hexachlorocyclohexane (HCH) isomers (mainly alpha-, beta-, gamma- and delta-HCH) in a soil-plant-air system. A field assay was carried out with two plant species, Cynara scolymus L. and Erica sp., which were planted either: (i) directly in the HCH-contaminated soil; or (ii) in pots filled with uncontaminated soil, which were placed in the HCH-contaminated soil. Both plant species accumulated HCH in their tissues, with relatively higher accumulation in above-ground biomass than in roots. The beta-HCH isomer was the main isomer in all plant tissues. Adsorption of HCH by the roots from contaminated soil (soil-->root pathway) and adsorption through the aerial biomass from either the surrounding air, following volatilization of the contaminant (soil-->air-->shoot pathway), and/or contact with air-suspended particles contaminated with HCH (soil particles-->shoot pathway) were the main mechanisms of accumulation. These results may have important implications for the use of plants for reducing the transfer of contaminants via the atmosphere.

  15. Metal transfer to plants grown on a dredged sediment: use of radioactive isotope 203Hg and titanium.

    PubMed

    Caille, Nathalie; Vauleon, Clotilde; Leyval, Corinne; Morel, Jean-Louis

    2005-04-01

    Improperly disposed of dredged sediments contaminated with metals may induce long-term leaching and an increase of metal concentrations in ground waters and vegetal cover plants. The objective of the study was to quantify the sediment-to-plant transfer of Cu, Pb, Hg and Zn with a particular focus on the pathway of Hg and to determine whether the establishment of vegetal cover modifies the metal availability. A pot experiment with rape (Brassica napus), cabbage (Brassica oleraccea) and red fescue (Festuca rubra) was set up using a sediment first spiked with the radioisotope 203Hg. Zinc concentrations (197-543 mg kg(-1) DM) in leaves were higher than Cu concentration (197-543 mg kg(-1) DM), Pb concentration (2.3-2.6 mg kg(-1) DM) and Hg concentration (0.9-1.7 mg kg(-1) DM). Leaves-to-sediment ratios decreased as follows: Zn > Cu > Hg > Pb. According to Ti measurements, metal contamination by dry deposition was less than 1%. Mercury concentration in plant leaves was higher than European and French thresholds. Foliar absorption of volatile Hg was a major pathway for Hg contamination with a root absorption of Hg higher in rape than in cabbage and red fescue. Growth of each species increased Cu solubility. Zinc solubility was increased only in the presence of rape. The highest increase of Cu solubility was observed for red fescue whereas this species largely decreased Zn solubility. Dissolved organic carbon (DOC) measurements suggested that Cu solubilisation could result from organic matter or release of natural plant exudates. Dissolved inorganic carbon (DIC) measures suggested that the high Zn solubility in the presence of rape could originate from a generation of acidity in rape rhizosphere and a subsequent dissolution of calcium carbonates. Consequently, emission of volatile Hg from contaminated dredged sediments and also the potential increase of metal solubility by a vegetal cover of grass when used in phytostabilisation must be taken into account by decision

  16. Genetic diversity and antifungal activity of native Pseudomonas isolated from maize plants grown in a central region of Argentina.

    PubMed

    Cordero, Paula; Cavigliasso, Andrea; Príncipe, Analía; Godino, Agustina; Jofré, Edgardo; Mori, Gladys; Fischer, Sonia

    2012-07-01

    Pseudomonas strains producing antimicrobial secondary metabolites play an important role in the biocontrol of phytopathogenic fungi. In this study, native Pseudomonas spp. isolates were obtained from the rhizosphere, endorhizosphere and bulk soil of maize fields in Córdoba (Argentina) during both the vegetative and reproductive stages of plant growth. However, the diversity based on repetitive-element PCR (rep-PCR) and amplified ribosomal DNA restriction analysis (ARDRA) fingerprinting was not associated with the stage of plant growth. Moreover, the antagonistic activity of the native isolates against phytopathogenic fungi was evaluated in vitro. Several strains inhibited members of the genera Fusarium, Sclerotinia or Sclerotium and this antagonism was related to their ability to produce secondary metabolites. A phylogenetic analysis based on rpoB or 16S rRNA gene sequences confirmed that the isolates DGR22, MGR4 and MGR39 with high biocontrol potential belonged to the genus Pseudomonas. Some native strains of Pseudomonas were also able to synthesise indole acetic acid and to solubilise phosphate, thus possessing potential plant growth-promoting (PGPR) traits, in addition to their antifungal activity. It was possible to establish a relationship between PGPR or biocontrol activity and the phylogeny of the strains. The study allowed the creation of a local collection of indigenous Pseudomonas which could be applied in agriculture to minimise the utilisation of chemical pesticides and fertilisers.

  17. Productivity of poplar grown on short rotation in Spain: Influence of the rotation age and plant density

    SciTech Connect

    Ciria, M.P.; Mazon, P.; Carrasco, J.

    1995-11-01

    The objective of this work is to evaluate the growth potential and biomass productivity of poplar on short rotation for different growth cycles and plant densities in southern Europe. Five poplar clones have been tested: Unal, Beaupre, Hunnegen, Boelare and Raspalje, all are hybrid clones P. trichocarpa x P. deltoides. For each clone, plant densities of 10000, 5000, 2500 and 1666 trees/ha have been assayed, for growth cycles of 2, 3, 4 and 5 years. The experimentation was initiated in 1986 at Castilla y Leon, region in Spain. The situation of the plantation is 41{degrees}36`N and 2{degrees}30`E (Greenwich meridiane), at an altitude of 1010 m above the sea level. The average rain precipitation is of about 550 mm/year and the average temperature, 10.5{degrees}C. The parameters evaluated for each plant after harvesting have been: total dry weight of the aerial part and dry weight, height and basal diameter of the stems. The highest biomass productivity, next to 20 t/ha.year, was achieved for Raspalje clone, utilizing 10000 trees/ha plantation density and growth cycle of 5 years. Under these conditions the average diameter of the stems was 9.5 cm and the average height of the trees was 7.9 m.

  18. Bioaccumulation and distribution of heavy metals in Maize, Oat and Sorghum Plants, grown in industrially polluted region

    NASA Astrophysics Data System (ADS)

    Angelova, Violina; Ivanova, Radka; Ivanov, Krasimir

    2010-05-01

    The uptake of heavy metals (Cd, Pb and Zn) by maize, oat and sorghum plants cultivated, under field conditions, in industrially polluted soils was studied. The experimental plots were situated at different distances (0.1, 2.0 and 15.0 km) from the source of pollution - the Non-Ferrous Metal Works near Plovdiv, Bulgaria. On reaching commercial ripeness the crops were gathered and the contents of heavy metals in their different parts - roots, stems, leaves and grains, were determined after dry ashing. The quantitative measurements were carried out with ICP. A clearly distinguished species peculiarity existed in the accumulation of heavy metals in the vegetative and reproductive organs of the studied crops. Sorghum plants accumulated larger heavy metal quantities compared to maize and oat plants, as the major part of heavy metals was retained by roots and a very small part was translocated to epigeous parts. The studied crops may be considered as metal-tolerant crops and may be cultivated on soils which are low, medium or highly contaminated with lead, zinc and cadmium, as they do not show a tendency of accumulating these elements in epigeous parts and grains above the maximum permissible concentrations. The possible use of aboveground mass and grains for animal food guarantees the economic expedience upon the selection of these crops. Acknowledgment: This work is supported by the Bulgarian Ministry of Education, Project DO-02-87/08.

  19. Characterization of Epiphytic Bacterial Communities from Grapes, Leaves, Bark and Soil of Grapevine Plants Grown, and Their Relations

    PubMed Central

    Martins, Guilherme; Lauga, Béatrice; Miot-Sertier, Cécile; Mercier, Anne; Lonvaud, Aline; Soulas, Marie-Louise; Soulas, Guy; Masneuf-Pomarède, Isabelle

    2013-01-01

    Despite its importance in plant health and crop quality, the diversity of epiphytic bacteria on grape berries and other plant parts, like leaves and bark, remains poorly described, as does the role of telluric bacteria in plant colonization. In this study, we compare the bacterial community size and structure in vineyard soils, as well as on grapevine bark, leaves and berries. Analyses of culturable bacteria revealed differences in the size and structure of the populations in each ecosystem. The highest bacteria population counts and the greatest diversity of genera were found in soil samples, followed by bark, grapes and leaves. The identification of isolates revealed that some genera – Pseudomonas, Curtobacterium, and Bacillus – were present in all ecosystems, but in different amounts, while others were ecosystem-specific. About 50% of the genera were common to soil and bark, but absent from leaves and grapes. The opposite was also observed: grape and leaf samples presented 50% of genera in common that were absent from trunk and soil. The bacterial community structure analyzed by T-RFLP indicated similarities between the profiles of leaves and grapes, on the one hand, and bark and soil, on the other, reflecting the number of shared T-RFs. The results suggest an interaction between telluric bacterial communities and the epiphytic bacteria present on the different grapevine parts. PMID:24023666

  20. Regulation of UVR8 photoreceptor dimer/monomer photo-equilibrium in Arabidopsis plants grown under photoperiodic conditions.

    PubMed

    Findlay, Kirsten M W; Jenkins, Gareth I

    2016-08-01

    The UV RESISTANCE LOCUS 8 (UVR8) photoreceptor specifically mediates photomorphogenic responses to UV-B. Photoreception induces dissociation of dimeric UVR8 into monomers to initiate responses. However, the regulation of dimer/monomer status in plants growing under photoperiodic conditions has not been examined. Here we show that UVR8 establishes a dimer/monomer photo-equilibrium in plants growing in diurnal photoperiods in both controlled environments and natural daylight. The photo-equilibrium is determined by the relative rates of photoreception and dark-reversion to the dimer. Experiments with mutants in REPRESSOR OF UV-B PHOTOMORPHOGENESIS 1 (RUP1) and RUP2 show that these proteins are crucial in regulating the photo-equilibrium because they promote reversion to the dimer. In plants growing in daylight, the UVR8 photo-equilibrium is most strongly correlated with low ambient fluence rates of UV-B (up to 1.5 μmol m(-2) s(-1) ), rather than higher fluence rates or the amount of photosynthetically active radiation. In addition, the rate of reversion of monomer to dimer is reduced at lower temperatures, promoting an increase in the relative level of monomer at approximately 8-10 °C. Thus, UVR8 does not behave like a simple UV-B switch under photoperiodic growth conditions but establishes a dimer/monomer photo-equilibrium that is regulated by UV-B and also influenced by temperature.

  1. Characterization of epiphytic bacterial communities from grapes, leaves, bark and soil of grapevine plants grown, and their relations.

    PubMed

    Martins, Guilherme; Lauga, Béatrice; Miot-Sertier, Cécile; Mercier, Anne; Lonvaud, Aline; Soulas, Marie-Louise; Soulas, Guy; Masneuf-Pomarède, Isabelle

    2013-01-01

    Despite its importance in plant health and crop quality, the diversity of epiphytic bacteria on grape berries and other plant parts, like leaves and bark, remains poorly described, as does the role of telluric bacteria in plant colonization. In this study, we compare the bacterial community size and structure in vineyard soils, as well as on grapevine bark, leaves and berries. Analyses of culturable bacteria revealed differences in the size and structure of the populations in each ecosystem. The highest bacteria population counts and the greatest diversity of genera were found in soil samples, followed by bark, grapes and leaves. The identification of isolates revealed that some genera - Pseudomonas, Curtobacterium, and Bacillus - were present in all ecosystems, but in different amounts, while others were ecosystem-specific. About 50% of the genera were common to soil and bark, but absent from leaves and grapes. The opposite was also observed: grape and leaf samples presented 50% of genera in common that were absent from trunk and soil. The bacterial community structure analyzed by T-RFLP indicated similarities between the profiles of leaves and grapes, on the one hand, and bark and soil, on the other, reflecting the number of shared T-RFs. The results suggest an interaction between telluric bacterial communities and the epiphytic bacteria present on the different grapevine parts.

  2. The copper tolerance strategies and the role of antioxidative enzymes in three plant species grown on copper mine.

    PubMed

    Boojar, Massod Mashhadi Akbar; Goodarzi, Faranak

    2007-05-01

    This study was undertaken to identify the strategies and the status of antioxidant enzyme activities involved in three plant species tolerance against Cu-toxicity in copper mine. The following methods were used for evaluations in three wild type species; Datura stramonium, Malva sylvestris and Chenopodium ambrosioides. The level of chlorophyll and the activities of superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase (CAT) by spectrometry, malondialdehyde (MDA) and dityrosine by HPLC and the levels of Cu in tissues and soils by atomic absorption spectrometry (AAS). Analysis showed that total and available copper were at toxic levels for plants growing on contaminated soil (zone 1). However, there were not any visual and conspicuous symptoms of Cu toxicity in plant species. Among three species, excess copper was transferred only into the D. stramonium and C. ambrosioides tissues. The C. ambrosioides accumulated Cu in roots and then in leaves, in which the leaves chloroplasts stored Cu around two times of vacuoles. In D. stramonium most of Cu was accumulated in leaves in which the storage rate in vacuoles and chloroplasts were 42% and 8%, respectively. In zone 1, the chlorophyll levels increased significantly in leaves of C. ambrosioides with respect to the same plant growing on uncontaminated soil (zone 2). There was insignificant decrease in chlorophyll content of D. stramonium leaves, collected from zone 1 with respect to zone 2. The D. stramonium and C. ambrosioides in zone 1, both revealed significant increase in their tissues antioxidant enzyme activities in comparison with the same samples of zone 2. There was significant elevation in oxidative damage biomarkers; MDA and dityrosine, when the aerial parts of D. stramonium in zone 1 were compared with the same parts of zone 2. We concluded that there were different tolerance strategies in studied plant species that protected them against copper toxicity. In M. sylvestris, exclusion of Cu from

  3. Growth and elemental accumulation of plants grown in acidic soil amended with coal fly ash-sewage sludge co-compost

    SciTech Connect

    Wong, J.W.C.; Selvam, A.

    2009-10-15

    A greenhouse experiment was conducted to evaluate the growth and heavy-metal accumulation of Brassica chinensis and Agropyron elongatum in 10 and 25% ash-sludge co-compost (ASC)-amended loamy acidic soil (pH 4.51) at two different application rates: 20% and 40% (v/v). Soil pH increased, whereas electrical conductivity decreased with the amendment of ASC to soil. Bioavailable Cu, Zn, and Mn contents of ASC-amended soil decreased, whereas Ni, Pb, and B contents increased. Concentrations of bioavailable Cu, Zn, and Mn in sludge compost (SC)-amended soils were 5.57, 20.8, and 8.19 mg kg{sup -1}, respectively. These concentrations were significantly lower than those in soil receiving an application rate of 20 or 25% ASC as 2.64, 8.48, and 5.26 mg kg(-1), respectively. Heavy metals and B contents of the composting mass significantly increased with an increase in ASC application rate from 20 to 40% (6.2 to 16.6 mg kg{sup -1} for 10% ASC- and 9.4 to 18.6 mg kg{sup -1} for 25% ASC-amended soil. However, when the ash content in co-compost increased from 10 to 25% during composting, bioavailable heavy-metal contents decreased. However, B contents increased with an increase in ash content. Addition of co-composts increased the dry-weight yield of the plants, and this increase was more obvious as the ash amendment rate in the co-composts and the ASC application rate increased. In case of B. chinensis, the biomass of 2.84 g/plant for 40% application of 25% ASC was significantly higher than SC (0.352 g/plant), which was 40% application of 10% ASC (0.434 g/plant) treatments. However, in A. elongatum, the differences between biomass of plants grown with 10% (1.34-1.94 g/ plant) and 25% ASC (2.12-2.21 g/plant) were not significantly different. ASC was favorable in increasing the growth of B. chinensis and A. elongatum. The optimal ash amendment to the sludge composting and ASC application rates were at 25 and 20%, respectively.

  4. In vitro antagonistic activity, plant growth promoting traits and phylogenetic affiliation of rhizobacteria associated with wild plants grown in arid soil.

    PubMed

    El-Sayed, Wael S; Akhkha, Abdellah; El-Naggar, Moustafa Y; Elbadry, Medhat

    2014-01-01

    The role of plant growth-promoting rhizobacteria (PGPR) in adaptation of plants in extreme environments is not yet completely understood. For this study native bacteria were isolated from rhizospeheric arid soils and evaluated for both growth-promoting abilities and antagonistic potential against phytopathogenic fungi and nematodes. The phylogentic affiliation of these representative isolates was also characterized. Rhizobacteria associated with 11 wild plant species from the arid soil of Almadinah Almunawarah, Kingdom of Saudi Arabia (KSA) were investigated. From a total of 531 isolates, only 66 bacterial isolates were selected based on their ability to inhibit Fusarium oxysporum, and Sclerotinia sclerotiorum. The selected isolates were screened in vitro for activities related to plant nutrition and plant growth regulation as well as for antifungal and nematicidal traits. Isolated bacteria were found to exhibit capabilities in fix atmospheric nitrogen, produce ammonia, indoleacetic acid (IAA), siderophores, solubilize phosphate and zinc, and showed an antagonistic potential against some phytopathogenic fungi and one nematode species (Meloidogyne incognita) to various extent. Isolates were ranked by their potential ability to function as PGPR. The 66 isolates were genotyped using amplified rDNA restriction analysis (ARDRA) and 16S rRNA gene sequence analysis. The taxonomic composition of the representative genotypes from both rhizosphere and rhizoplane comprised Bacillus, Enterobacter and Pseudomonas. Out of the 10 genotypes, three strains designated as PHP03, CCP05, and TAP02 might be regarded as novel strains based on their low similarity percentages and high bootstrap values. The present study clearly identified specific traits in the isolated rhizobacteria, which make them good candidates as PGPR and might contribute to plant adaption to arid environments. Application of such results in agricultural fields may improve and enhance plant growth in arid soils.

  5. In vitro antagonistic activity, plant growth promoting traits and phylogenetic affiliation of rhizobacteria associated with wild plants grown in arid soil

    PubMed Central

    El-Sayed, Wael S.; Akhkha, Abdellah; El-Naggar, Moustafa Y.; Elbadry, Medhat

    2014-01-01

    The role of plant growth-promoting rhizobacteria (PGPR) in adaptation of plants in extreme environments is not yet completely understood. For this study native bacteria were isolated from rhizospeheric arid soils and evaluated for both growth-promoting abilities and antagonistic potential against phytopathogenic fungi and nematodes. The phylogentic affiliation of these representative isolates was also characterized. Rhizobacteria associated with 11 wild plant species from the arid soil of Almadinah Almunawarah, Kingdom of Saudi Arabia (KSA) were investigated. From a total of 531 isolates, only 66 bacterial isolates were selected based on their ability to inhibit Fusarium oxysporum, and Sclerotinia sclerotiorum. The selected isolates were screened in vitro for activities related to plant nutrition and plant growth regulation as well as for antifungal and nematicidal traits. Isolated bacteria were found to exhibit capabilities in fix atmospheric nitrogen, produce ammonia, indoleacetic acid (IAA), siderophores, solubilize phosphate and zinc, and showed an antagonistic potential against some phytopathogenic fungi and one nematode species (Meloidogyne incognita) to various extent. Isolates were ranked by their potential ability to function as PGPR. The 66 isolates were genotyped using amplified rDNA restriction analysis (ARDRA) and 16S rRNA gene sequence analysis. The taxonomic composition of the representative genotypes from both rhizosphere and rhizoplane comprised Bacillus, Enterobacter and Pseudomonas. Out of the 10 genotypes, three strains designated as PHP03, CCP05, and TAP02 might be regarded as novel strains based on their low similarity percentages and high bootstrap values. The present study clearly identified specific traits in the isolated rhizobacteria, which make them good candidates as PGPR and might contribute to plant adaption to arid environments. Application of such results in agricultural fields may improve and enhance plant growth in arid soils

  6. Alfalfa containing the glyphosate-tolerant trait has no effect on feed intake, milk composition, or milk production of dairy cattle.

    PubMed

    Combs, D K; Hartnell, G F

    2008-02-01

    The objective of this experiment was to assess if feeding glyphosate-tolerant alfalfa affects feed intake, milk composition, or milk production of dairy cows. One alfalfa (Medicago sativa), variety expressing the CP4 EPSPS protein and grown in southeastern Washington State was harvested at the late vegetative stage as hay. Three commercial conventional varieties of alfalfa hay of similar nutrient composition and harvested in the same geographic region were fed to cows as controls. The commercial hays were selected to be similar in crude protein [18% of dry matter (DM)] and neutral detergent fiber (40% of DM) to the glyphosate-tolerant hay. Sixteen multiparous Holstein cows were fed diets containing alfalfa hay (39.7% of diet DM) from either the glyphosate-tolerant alfalfa, or 1 of the 3 conventional varieties. Diets contained at least 15.7% crude protein and 29% neutral detergent fiber. Experimental design was a replicated 4 x 4 Latin square. Periods were 28 d and feed intake, milk yield, and milk composition were summarized over the last 14 d of each period. Daily milk yield (38.0 kg) and 4% fat-corrected milk (34.7 kg) were not affected by treatment. Milk fat (3.44%) and milk true protein (2.98%) were also not affected by source of hay. Milk lactose (4.72%) and soldis-not-fat (8.5%) did not differ due to treatment. Dry matter intake was similar across treatments (24.4 kg/d). These results are consistent with data from feeding trials with other glyphosate-tolerant crops and previously reported compositional comparisons of glyphosate-tolerant alfalfa with controls. Milk production, milk composition, feed intake, and feed efficiency were not affected by feeding diets that contained nearly 40% glyphosate-tolerant alfalfa hay to lactating dairy cows.

  7. Flavone Limitations to Root Nodulation and Symbiotic Nitrogen Fixation in Alfalfa 1

    PubMed Central

    Kapulnik, Yoram; Joseph, Cecillia M.; Phillips, Donald A.

    1987-01-01

    Transcription of the nodABC genes in Rhizobium meliloti is required for root nodule formation in alfalfa (Medicago sativa L.) and occurs when specific compounds, such as the flavone luteolin, are supplied by the host plant. Results reported here indicate how luteolin in the root and rhizosphere can affect subsequent N2 fixation and plant growth. Previous experiments with `Hairy Peruvian 32' (HP32), an alfalfa population produced from `Hairy Peruvian' (HP) by two generations of selection for increased N2 fixation and growth, found that HP32 had more root nodules and fixed more N2 than the parental HP population. In the present study, flavonoid extracts of HP32 seedling roots are shown to contain a 60% higher concentration of compounds that induce transcription of a nodABC-lacZ fusion in R. meliloti than comparable extracts of HP roots. Chromatographic data indicated that HP32 roots had a 77% higher concentration of luteolin than HP roots. Adding 10 micromolar luteolin to the rhizosphere of HP seedlings increased nodulation, N2 fixation, total N, and total dry weight but had no effect on nitrate assimilation. These data show that normal levels of flavone nodulation signals in the rhizosphere of HP alfalfa can limit root nodulation, symbiotic N2 fixation, and seedling growth and suggest that one mechanism for increasing N2 fixation can be the genetic enhancement of specific biochemical signals which induce nodulation genes in Rhizobium. PMID:16665583

  8. Saprobe fungi decreased the sensitivity to the toxic effect of dry olive mill residue on arbuscular mycorrhizal plants.

    PubMed

    Sampedro, I; Aranda, E; Díaz, R; García-Sanchez, M; Ocampo, J A; García-Romera, I

    2008-02-01

    We studied the influence of olive mill dry residue (DOR) treated with saprobe fungi on growth of tomato and alfalfa colonized by Glomus deserticola. The application of 25g kg(-1) of dry DOR to soil decreased the shoot and root dry weight of tomato and alfalfa. Plants were more sensitive to the toxicity of DOR when colonized with the arbuscular mycorrhizal (AM) fungi. The sensitivity of both plants to the toxicity of DOR differed according to whether they were colonized by G. deserticola or by indigenous AM fungi. The phytotoxicity of DOR towards tomato and alfalfa was decreased by incubation the residue before planting with saprobe fungi for 20wk. The beneficial effects of AM fungi on plant growth added with DOR incubated with saprobe fungi depend of the type of the plant and AM fungi. The contribution of AM fungi to the beneficial effect of DOR incubated with saprobe fungi varied according to the type of the plant and AM fungi. G. deserticola increased the shoot and root dry weight of plants when they were grown in the presence of DOR incubated with saprobe fungi for 20wk. The beneficial effect of saprobe fungi on the dry weight and the level of AM mycorrhization of plants seem to be related to the decrease caused by these fungi in the phenol concentration in DOR. However, the toxicity of DOR due to substances other than phenols can not be ignored. The use of certain saprobe and AM fungi allows the possibility of using DOR as an organic fertilizer.

  9. Tomato yellow leaf curl virus infection mitigates the heat stress response of plants grown at high temperatures.

    PubMed

    Ghandi, Anfoka; Adi, Moshe; Lilia, Fridman; Linoy, Amrani; Or, Rotem; Mikhail, Kolot; Mouhammad, Zeidan; Henryk, Czosnek; Rena, Gorovits

    2016-01-21

    Cultured tomatoes are often exposed to a combination of extreme heat and infection with Tomato yellow leaf curl virus (TYLCV). This stress combination leads to intense disease symptoms and yield losses. The response of TYLCV-susceptible and resistant tomatoes to heat stress together with viral infection was compared. The plant heat-stress response was undermined in TYLCV infected plants. The decline correlated with the down-regulation of heat shock transcription factors (HSFs) HSFA2 and HSFB1, and consequently, of HSF-regulated genes Hsp17, Apx1, Apx2 and Hsp90. We proposed that the weakened heat stress response was due to the decreased capacity of HSFA2 to translocate into the nuclei of infected cells. All the six TYLCV proteins were able to interact with tomato HSFA2 in vitro, moreover, coat protein developed complexes with HSFA2 in nuclei. Capturing of HSFA2 by viral proteins could suppress the transcriptional activation of heat stress response genes. Application of both heat and TYLCV stresses was accompanied by the development of intracellular large protein aggregates containing TYLCV proteins and DNA. The maintenance of cellular chaperones in the aggregated state, even after recovery from heat stress, prevents the circulation of free soluble chaperones, causing an additional decrease in stress response efficiency.

  10. The coupling of the plant and microbial catabolisms of phenanthrene in the rhizosphere of Medicago sativa.

    PubMed

    Muratova, Anna; Dubrovskaya, Ekaterina; Golubev, Sergey; Grinev, Vyacheslav; Chernyshova, Marina; Turkovskaya, Olga

    2015-09-01

    We studied the catabolism of the polycyclic aromatic hydrocarbon phenanthrene by four rhizobacterial strains and the possibility of enzymatic oxidation of this compound and its microbial metabolites by the root exudates of alfalfa (Medicago sativa L.) in order to detect the possible coupling of the plant and microbial metabolisms under the rhizospheric degradation of the organic pollutant. A comparative study of phenanthrene degradation pathways in the PAH-degrading rhizobacteria Ensifer meliloti, Pseudomonas kunmingensis, Rhizobium petrolearium, and Stenotrophomonas sp. allowed us to identify the key metabolites from the microbial transformation of phenanthrene, including 9,10-phenanthrenequinone, 2-carboxybenzaldehyde, and 1-hydroxy-2-naphthoic, salicylic, and o-phthalic acids. Sterile alfalfa plants were grown in the presence and absence of phenanthrene (0.03 g kg(-1)) in quartz sand under controlled environmental conditions to obtain plant root exudates. The root exudates were collected, concentrated by ultrafiltration, and the activity of oxidoreductases was detected spectrophotometrically by the oxidation rate for various substrates. The most marked activity was that of peroxidase, whereas the presence of oxidase and tyrosinase was detected on the verge of the assay sensitivity. Using alfalfa root exudates as a crude enzyme preparation, we found that in the presence of the synthetic mediator, the plant peroxidase could oxidize phenanthrene and its microbial metabolites. The results indicate the possibility of active participation of plants in the rhizospheric degradation of polycyclic aromatic hydrocarbons and their microbial metabolites, which makes it possible to speak about the coupling of the plant and microbial catabolisms of these contaminants in the rhizosphere.

  11. Inhibitory potential of pure isoflavonoids, red clover, and alfalfa extracts on hemoglobin glycosylation

    PubMed Central

    Hosseini, Mohsen; Asgary, Sedigheh; Najafi, Somayeh

    2015-01-01

    BACKGROUND Non-enzymatic glycosylation of hemoglobin is complications of diabetes. Antioxidant system imbalance can result in the emergence of free radicals’ destructive effects in the long-term. Red clover (Trifolium pratense L.) and alfalfa (Medicago sativa L.) contain isoflavonoids and have antioxidant activity. This experimental study evaluated the inhibitory activity of pure isoflavonoids (daidzein and genistein), red clover and alfalfa extracts on hemoglobin glycosylation. METHODS This study was performed in Iran. Stock solution of hydroalcoholic extracts of red clover and alfalfa in concentrations of 1 and 10 g/100 ml and stock solution of daidzein and genistein in concentrations of 250 ng, 500 ng, 25 µg and 250 µg/100 ml were prepared as case groups. Control group was without hydroalcoholic extracts of plants and pure isoflavonoids. All experiments were performed in triplicate. Hemoglobin was prepared and antioxidant activities were investigated to estimate degree of nonenzymatic hemoglobin glycosylation. RESULTS There was no significantly difference between used extracts (extract of red clover and alfalfa) and control of the hemoglobin glycosylation but using daidzein (P = 0.046, 0.029 and 0.021, respectively) and genistein (P = 0.034, 0.036 and 0.028) significantly inhibited (P < 0.050) this reaction in 25 µg/100 ml, 250 and 500 ng/100 ml concentrations when compared to control. in 25 µg/100 ml, 250 ng and 500 ng/100 ml concentrations percentage of inhibition were 32, 80 and 74.5% respectively with used of daidzein and were 21, 83 and 76% respectively with consumption of genistein. CONCLUSION According to decrease of glycation of hemoglobin with isoflavonoids, two used plant in this study containing isoflavonoid may be useful on diabetes. PMID:26405442

  12. Expression of a fungal ferulic acid esterase in alfalfa modifies cell wall digestibility

    PubMed Central

    2014-01-01

    Background Alfalfa (Medicago sativa) is an important forage crop in North America owing to its high biomass production, perennial nature and ability to fix nitrogen. Feruloyl esterase (EC 3.1.1.73) hydrolyzes ester linkages in plant cell walls and has the potential to further improve alfalfa as biomass for biofuel production. Results In this study, faeB [GenBank:AJ309807] was synthesized at GenScript and sub-cloned into a novel pEACH vector containing different signaling peptides to target type B ferulic acid esterase (FAEB) proteins to the apoplast, chloroplast, endoplasmic reticulum and vacuole. Four constructs harboring faeB were transiently expressed in Nicotiana leaves, with FAEB accumulating at high levels in all target sites, except chloroplast. Stable transformed lines of alfalfa were subsequently obtained using Agrobacterium tumefaciens (LBA4404). Out of 136 transgenic plants regenerated, 18 independent lines exhibited FAEB activity. Subsequent in vitro digestibility and Fourier transformed infrared spectroscopy (FTIR) analysis of FAEB-expressing lines showed that they possessed modified cell wall morphology and composition with a reduction in ester linkages and elevated lignin content. Consequently, they were more recalcitrant to digestion by mixed ruminal microorganisms. Interestingly, delignification by alkaline peroxide treatment followed by exposure to a commercial cellulase mixture resulted in higher glucose release from transgenic lines as compared to the control line. Conclusion Modifying cell wall crosslinking has the potential to lower recalcitrance of holocellulose, but also exhibited unintended consequences on alfalfa cell wall digestibility due to elevated lignin content. The combination of efficient delignification treatment (alkaline peroxide) and transgenic esterase activity complement each other towards efficient and effective digestion of transgenic lines. PMID:24650274

  13. Plant available nitrogen from anaerobically digested sludge and septic tank sludge applied to crops grown in the tropics.

    PubMed

    Sripanomtanakorn, S; Polprasert, C

    2002-04-01

    Agricultural land is an attractive alternative for the disposal of biosolids since it utilises the recyclable nutrients in the production of crops. In Thailand and other tropical regions, limited field-study information exists on the effect of biosolids management strategies on crop N utilisation and plant available N (PAN) of biosolids. A field study was conducted to quantify the PAN of the applied biosolids, and to evaluate the N uptake rates of some tropical crops. Sunflower (Helianthus annuus) and tomato (Lycopersicon esculentum) were chosen in this study. Two types of biosolids used were: anaerobically digested sludge and septic tank sludge. The soil is acid sulfate and is classified as Sulfic Tropaquepts with heavy clay in texture. The anaerobically digested sludge applied rates were: 0, 156 and 312 kg N ha(-1) for the sunflower plots, and 0, 586, and 1172 kg N ha(-1) for the tomato plots. The septic tank sludge applied rates were: 0, 95 and 190 kg N ha(-1) for the sunflower plots, and 0, 354 and 708 kg N ha(-1) for the tomato plots, respectively. The results indicated the feasibility of applying biosolids to grow tropical crops. The applications of the anaerobically digested sludge and the septic tank sludge resulted in the yields of sunflower seeds and tomato fruits and the plant N uptakes comparable or better than that applied with only the chemical fertiliser. The estimated PAN of the anaerobically digested sludge was about 27-42% of the sludge organic N during the growing season. For the septic tank sludge, the PAN was about 15-58% of the sludge organic N. It is interesting to observe that an increase of the rate of septic tank sludge incorporated into this heavy clay soil under the cropping system resulted in the decrease of N mineralisation rate. This situation could cause the reduction of yield and N uptake of crops.

  14. Soil characterization and differential patterns of heavy metal accumulation in woody plants grown in coal gangue wastelands in Shaanxi, China.

    PubMed

    Yakun, Shi; Xingmin, Mu; Kairong, Li; Hongbo, Shao

    2016-07-01

    Soil contamination by heavy metals in coal mine wastelands is a significant environmental issue in most developing countries. The purpose of this study is to evaluate contamination characteristics in the coal mine wastelands of Sanlidong coal mine, Tongchuan, China. To achieve this goal, we conducted field sampling work, followed by further analysis of the properties of soil contamination and accumulation characteristics in woody plants. At this site, the pH value ranged from 4.41 to 7.88, and the nutrient content of the soil rose gradually with the time after deposition due to the weathering effect improving the soil quality. Meanwhile, the levels of Cd, Cr, Cu, Ni, and Zn gradually decreased with the passage time. Generally, heavy metal contamination was found to be more serious in the discharge refuse area, with Cd contamination at moderate or heavy levels; Ni, Zn, and Cu contamination at light levels; and with no Cr contamination. The geoaccumulation index (I geo) was highest for Cd (2.38-3.14), followed by Ni, Zn, Cu, and Cr. Heavy metals accumulated on the lower slopes and spread to the surrounding areas via hydrodynamic effects and wind. According to transfer and enrichment coefficient analyses, Robinia pseudoacacia, Ulmus pumila, and Hippophae rhamnoides with considerable biomass could be used as pollution-resistant tree species for vegetation restoration. This study provided a theoretical basis for the restoration of the ecological environment in the mining area. This report described a link between heavy metal contamination of soils and growth dynamics of woody plants in China.

  15. Intended release and actual retention of alfalfa leafcutting bees (Hymenoptera: Megachilidae) for pollination in commercial alfalfa seed fields.

    PubMed

    Pitts-Singer, Theresa L

    2013-04-01

    Low, medium, and high stocking densities (15,000; 30,000; and 45,000-50,000 bees per acre, respectively) of Megachile rotundata (F.) (Hymenoptera: Megachilidae), the alfalfa leafcutting bee, were released over 4 yr in three research plots of Utah alfalfa, Medicago sativa L. (Fabaceae), planted at seed-production rates. A low percentage of bees (46-79% of released) survived the incubation and field-emergence processes; of those bees, the number of females that established at the nesting sites was 25-100%. Of the three field sites, one site consistently retained more females and produced more completed nests than the other sites, all of which usually had poor female establishment and progeny production. In addition, floral resources were depleted over time, but many flowers remained unvisited over the season. Nest production decreased over time, as numbers of flowers and female bees declined. Significant positive relationships were found between the intended stocking densities and 1) the number of females that actually survived incubation and field emergence and 2) the number of females that established nests. The number of females that established nests was positively affected by the number of females that survived to emerge in the field. The percentage of females that established was not significantly affected by the intended number of released bees, countering a prediction that the release of fewer bees would allow more females to establish nests and achieve high reproductive success. For growers, it may be more frugal to use modest numbers of M. rotundata for pollination, because many of the bees at medium and high stocking densities do not nest in grower-provided bee boards.

  16. Alfalfa suppression of weeds is affected by preceding crop

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Organic producers are seeking alternative tactics for weed control so that they can reduce their need for tillage. In this study, we examined the impact of the preceding crop on alfalfa suppression of weeds. Alfalfa was most competitive with weeds following soybean. When following spring wheat, v...

  17. 'Don' a Diploid Falcata Alfalfa for Western US Rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    'Don' (Reg. No. CV-______, PI _______) a diploid falcata alfalfa (Medicago sativa subsp falcata L.) developed by the Forage and Range Research Laboratory in Logan, Utah, in cooperation with the Utah Agricultural Experiment Station, Utah State University. Recent interest in falcata alfalfa has been ...

  18. Storage characteristics of large round alfalfa bales: dry hay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Losses of forage dry matter (DM) and quality in large round bales of alfalfa stored outdoors can be substantial. The objective of this research was to determine the effect of wrap type and storage method on the preservation of dry alfalfa bales stored outdoors. Several methods to wrap large round ...

  19. Persistence and diversity of rhizobial bacteria nodulating alfalfa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Most alfalfa seed is treated with an inoculant consisting of several strains of the nitrogen fixing bacterium Sinorhizobium meliloti to enhance nodulation of seedlings. One strategy for increasing alfalfa forage yields, particularly in less fertile sites, is selection and use of highly competitive a...

  20. Does Alfalfa-Hay NDFD Matter in a Dairy TMR?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three feeding trials were conducted to study the effect of alfalfa-hay in vitro neutral detergent fiber digestibility (IVNDFD, 48-hour laboratory incubation in rumen fluid) on Holstein dairy cow performance. Treatments (Lh, Ll, Hh, and Hl) included four alfalfa hays selected for relatively low-(L) o...

  1. Alfalfa: Potential For New Feed and Biofuel - USDFRC Research Update

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alfalfa hay is a major crop supporting U.S ruminant livestock industry, particularly dairy. Several cellulosic feedstocks will be needed to meet current ethanol production goals. Alfalfa has considerable potential as a feedstock for production of ethanol and other industrial materials because of i...

  2. Alfalfa forage and seed crop tolerance to flumioxazin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Weed control is an important component of producing high quality and high yielding alfalfa seed and forage. Flumioxazin was evaluated for weed control in alfalfa forage and seed production in 2007 and 2008 in Washington State. Flumioxazin applied at 0.14 and 0.28 kg ai/ha plus paraquat in February t...

  3. Satellite images reveal patterns in crop rotations with alfalfa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crops that follow alfalfa in rotation usually benefit from: i) reduced nitrogen (N) requirement from fertilizer or manure; ii) increased yield potential than when following other crops; and iii) reduced weed, insect, and disease pressure. Although benefits of alfalfa in crop rotations often depend o...

  4. Predicting fertilizer nitrogen response in corn following alfalfa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Correct prediction and application of alfalfa nitrogen (N) credits to first-year corn can reduce fertilizer N costs for growers, reduce over-application of N, and reduce the potential for water contamination. For decades, researchers have found that first-year corn following alfalfa often requires n...

  5. Complete genome sequence of the alfalfa latent virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alfalfa latent virus (ALV) is a member of the carlavirus group and occurs symptomlessly in alfalfa (Medicago sativa). In the US it is prevalent in Nebraska and Wisconsin. The virus is recognized as a strain of Pea streak virus (PeSV) So far, no complete genomic sequence of PSV or ALV is availab...

  6. Alfalfa leafcutting bee population dynamics, flower availability, and pollination rates in two Oregon alfalfa fields.

    PubMed

    Bosch, Jordi; Kemp, William P

    2005-08-01

    Since the 1970s, it has become increasingly difficult for U.S. alfalfa seed producers to maintain Megachile rotundata (F.) populations used for alfalfa, Medicago sativa L., pollination. In 1998, we monitored M. rotundata population dynamics and foraging behavior, as well as alfalfa bloom and pollination rates in two fields in eastern Oregon. Despite marked differences in bee management, establishment was very similar in the two fields (approximately 0.5 females per nesting cavity) and lagged peak bloom by approximately 2 wk. Pollination rates increased from 0-10% in the first 3 wk to 80-90% in week 4-5. By then, M. rotundata females had difficulty finding untripped (nonpollinated) flowers and visited large numbers of already tripped or not fully matured flowers. M. rotundata progeny mortality was very high (54-78%). Estimated seed yields were similar in both fields. We contend similar seed yields, and improved bee production, could be accomplished with smaller bee populations, better timed with alfalfa bloom.

  7. Opportunities exist to improve alfalfa and manure nitrogen crediting in corn following alfalfa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A survey of Minnesota growers was conducted to determine adoption of extension N rate guidelines for fertilizer and manure for first- and second-year corn (Zea mays L.) following alfalfa (Medicago sativa L.) (AC and ACC, respectively) during 2009 to 2011. There were 421 and 273 valid responses for A...

  8. Genome-Wide Association Mapping and Genomic Selection for Alfalfa (Medicago sativa) Forage Quality Traits

    PubMed Central

    Pecetti, Luciano; Brummer, E. Charles; Palmonari, Alberto; Tava, Aldo

    2017-01-01

    Genetic progress for forage quality has been poor in alfalfa (Medicago sativa L.), the most-grown forage legume worldwide. This study aimed at exploring opportunities for marker-assisted selection (MAS) and genomic selection of forage quality traits based on breeding values of parent plants. Some 154 genotypes from a broadly-based reference population were genotyped by genotyping-by-sequencing (GBS), and phenotyped for leaf-to-stem ratio, leaf and stem contents of protein, neutral detergent fiber (NDF) and acid detergent lignin (ADL), and leaf and stem NDF digestibility after 24 hours (NDFD), of their dense-planted half-sib progenies in three growing conditions (summer harvest, full irrigation; summer harvest, suspended irrigation; autumn harvest). Trait-marker analyses were performed on progeny values averaged over conditions, owing to modest germplasm × condition interaction. Genomic selection exploited 11,450 polymorphic SNP markers, whereas a subset of 8,494 M. truncatula-aligned markers were used for a genome-wide association study (GWAS). GWAS confirmed the polygenic control of quality traits and, in agreement with phenotypic correlations, indicated substantially different genetic control of a given trait in stems and leaves. It detected several SNPs in different annotated genes that were highly linked to stem protein content. Also, it identified a small genomic region on chromosome 8 with high concentration of annotated genes associated with leaf ADL, including one gene probably involved in the lignin pathway. Three genomic selection models, i.e., Ridge-regression BLUP, Bayes B and Bayesian Lasso, displayed similar prediction accuracy, whereas SVR-lin was less accurate. Accuracy values were moderate (0.3–0.4) for stem NDFD and leaf protein content, modest for leaf ADL and NDFD, and low to very low for the other traits. Along with previous results for the same germplasm set, this study indicates that GBS data can be exploited to improve both quality traits

  9. Alfalfa variety development. Minnesota Agripower Project, Task II research report

    SciTech Connect

    Lamb, J.F.S.; Samac, D.A.; Sheaffer, C.C.

    1997-10-30

    This report briefly summarizes preliminary results from crossbreeding alfalfa to develop desirable characteristics for a dedicated biomass feed stock. The varieties development is part of a larger project which includes preparation and gasification of the alfalfa stems for energy production, and use of the co-product alfalfa leaves in livestock feed. The desired alfalfa traits include winter hardiness, resistance to major pathogens, resistance to foliar disease complexes, many thick, tall, solid, non-lodging stems with high lignin content, delayed flowering, and high quality leaves retained through harvest. Currently no alfalfa varieties meet these criteria. Three crosses were made using old European varieties, with thick stems, and modern resistant varieties. The crossbreeds showed some resistance to diseases, but increased resistance is needed to maximize leaf and steam yield. 1 tab.

  10. Geotechnical Implications for the use of Alfalfa in Experimental Studies of Alluvial-Channel Morphology and Planform

    NASA Astrophysics Data System (ADS)

    Pollen, N.; Simon, A.

    2006-12-01

    Research on the interactions between vegetation and channel flow dynamics has shown that vegetation is an important control on river morphology and planform. Increased vegetation density is commonly linked to a decrease in bank erosion and lateral migration rates. Roots add to bank strength through the production of a reinforced soil-root matrix, and vegetation can also act to increase bank stability through its hydrological effects, including canopy interception, and removal of soil water through evapotranspiration. Flow dynamics are also affected by vegetation, with a number of studies showing a linkage between vegetation density and width- depth-velocity relations and bank roughness. To evaluate the effects of vegetation on channel morphology and planform, several experimental studies in flumes have used alfalfa sprouts (Medicago sativa) to seed the bed and banks of experimental channels. In such studies, the effects of vegetation are accounted for by qualitatively increasing the resistance of the bank material to lateral erosion. However, the material properties of alfalfa roots and stems, and the actual increase in resistance provided to the banks under different densities of alfalfa have thus far been ignored. To quantify this added erosion resistance, alfalfa sprouts were grown for 7 to 21 days, in sand with a d50 of 0.23 mm. At regular intervals, roots and stems were tested to measure tensile strength and forces required for pullout. Results of the tensile-strength measurements display the typical non-linear decrease of tensile strength (in MPa) with increasing root diameter but the curve is shifted to the left (weaker for a given diameter) of other riparian species. However, to calculate the increase in bank cohesion due to alfalfa roots, it is necessary to also account for the number of roots, and the distribution of different root diameters. The number of roots was calculated for a range of stem densities (0 to 10 stems/cm2), assuming a single, un

  11. Effects of diets containing alfalfa hay or barley flour mixed alfalfa silage on feeding behavior, productivity, rumen fermentation and blood metabolites in lactating cows.

    PubMed

    Khadem, Ali-Akbar; Sharifi, Majid; Afzalzadeh, Ahmad; Rezaeian, Mohammad

    2009-08-01

    The effects of barley flour on the fermentation parameters of alfalfa silage and on the productivity of dairy cows were investigated. Alfalfa forage was ensiled either with or without barley flour. Barley flour was soaked in water for 24 h before being mixed with alfalfa (12 kg: 100 kg dry matter bases) at ensiling. Eighteen multi-parous cows were assigned to three equal treatment groups using a completely randomized design. Three isocaloric and isonitrogenous total mixed rations containing alfalfa hay, ordinary alfalfa silage or barley flour mixed alfalfa silage were then prepared. The concentrations of ammonia nitrogen, acetic acid and butyric acid were lower in barley flour mixed alfalfa silage compared to that in ordinary alfalfa silage but the concentration of lactic acid was lower in the ordinary alfalfa silage. Feeding behavior, milk yield and composition, ruminal fermentation and blood metabolites were measured. Although dry matter intake and milk production were not affected, the effect of preparation of alfalfa influenced feeding behavior and rumen fermentation parameters. Cows on alfalfa silage diets spent longer ruminating compared to those fed alfalfa hay. The ruminal ammonia nitrogen and blood urea were affected by ensiling (alfalfa hay versus alfalfa silages) while both parameters were lower in cows fed on barley flour mixed alfalfa silage than those fed on ordinary silage. Although similar blood glucose was recorded for cows fed on alfalfa silages, it was higher in cows fed on alfalfa hay. It is concluded that the addition of barely flour when making alfalfa silage may improve both the fermentation process during ensilage and the ruminal ammonia nitrogen utilization with no significant effects on productivity.

  12. Inhibitory effect of essential oils obtained from plants grown in Colombia on yellow fever virus replication in vitro

    PubMed Central

    Meneses, Rocío; Ocazionez, Raquel E; Martínez, Jairo R; Stashenko, Elena E

    2009-01-01

    Background An antiviral drug is needed for the treatment of patients suffering from yellow fever. Several compounds present in plants can inactive in vitro a wide spectrum of animal viruses. Aim In the present study the inhibitory effect of essential oils of Lippia alba, Lippia origanoides, Oreganum vulgare and Artemisia vulgaris on yellow fever virus (YFV) replication was investigated. Methods The cytotoxicity (CC50) on Vero cells was evaluated by the MTT reduction method. The minimum concentration of the essential oil that inhibited virus titer by more than 50% (MIC) was determined by virus yield reduction assay. YFV was incubated 24 h at 4°C with essential oil before adsorption on Vero cell, and viral replication was carried out in the absence or presence of essential oil. Vero cells were exposed to essential oil 24 h at 37°C before the adsorption of untreated-virus. Results The CC50 values were less than 100 μg/mL and the MIC values were 3.7 and 11.1 μg/mL. The CC50/MIC ratio was of 22.9, 26.4, 26.5 and 8.8 for L. alba, L origanoides, O. vulgare and A. vulgaris, respectively. The presence of essential oil in the culture medium enhances the antiviral effect: L. origanoides oil at 11.1 μg/mLproduced a 100% reduction of virus yield, and the same result was observed with L. alba, O. vulgare and A. vulgaris oils at100 μg/mL. No reduction of virus yield was observed when Vero cells were treated with essential oil before the adsorption of untreated-virus. Conclusion The essential oils evaluated in the study showed antiviral activities against YFV. The mode of action seems to be direct virus inactivation. PMID:19267922

  13. Challenges and opportunities for improved N management in corn following alfalfa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    With some exceptions, the alfalfa nitrogen (N) credit usually eliminates the need for manure N and/or fertilizer N to economically optimize yield of the first corn crop following alfalfa. Alfalfa also can provide nearly one-half or more of the N requirement for the second corn crop following alfalfa...

  14. Phytotoxicity of three plant-based biodiesels, unmodified castor oil, and Diesel fuel to alfalfa (Medicago sativa L.), lettuce (Lactuca sativa L.), radish (Raphanus sativus), and wheatgrass (Triticum aestivum).

    PubMed

    Bamgbose, Ifeoluwa; Anderson, Todd A

    2015-12-01

    The wide use of plant-based oils and their derivatives, in particular biodiesel, have increased extensively over the past decade to help alleviate demand for petroleum products and improve the greenhouse gas emissions profile of the transportation sector. Biodiesel is regarded as a clean burning alternative fuel produced from livestock feeds and various vegetable oils. Although in theory these animal and/or plant derived fuels should have less environmental impact in soil based on their simplified composition relative to Diesel, they pose an environmental risk like Diesel at high concentrations when disposed. The aim of the present study was to ascertain the phytotoxicity of three different plant-derived biodiesels relative to conventional Diesel. For phytotoxicological analysis, we used seeds of four crop plants, Medicago sativa, Lactuca sativa, Raphanus sativus, and Triticum aestivum to analyze the germination of seeds in contaminated soil samples. The toxicological experiment was conducted with two different soil textures: sandy loam soil and silt loam soil. The studied plant-based biodiesels were safflower methyl-ester, castor methyl ester, and castor ethyl-ester. Biodiesel toxicity was more evident at high concentrations, affecting the germination and survival of small-seeded plants to a greater extent. Tolerance of plants to the biodiesels varied between plant species and soil textures. With the exception of R. sativus, all plant species were affected and exhibited some sensitivity to the fuels, such as delayed seedling emergence and slow germination (average=10 days) at high soil concentrations (0.85% for Diesel and 1.76% for the biodiesels). Tolerance of plants to soil contamination had a species-specific nature, and on average, decreased in the following order: Raphanus sativus (0-20%)>Triticum aestivum (10-40%) ≥ Medicago sativa> Lactuca sativa (80-100%). Thus, we conclude that there is some phytotoxicity associated with plant-based biodiesels. Further

  15. Occurrence of transgenic feral alfalfa (Medicago sativa subsp. sativa L.) in alfalfa seed production areas in the United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genetically-engineered glyphosate-resistant alfalfa (Medicago sativa subsp. sativa) was commercialized in 2011. The potential risk of transgene dispersal into the environment is not clearly understood for alfalfa, a perennial crop that is cross-pollinated by insects. We gathered data on feral and tr...

  16. Uptake of copper and cerium by alfalfa, lettuce and cucumber exposed to nCeO2 and nCuO through the foliage or the roots: Impacts on food quality, physiological and agronomical parameters

    NASA Astrophysics Data System (ADS)

    Hong, Jie

    Nanotechnology is increasingly attracting attention not only for its variety of applications in modern life, but for the potential negative effects that nanomaterials (NMs) can cause in the environment and human health. Studies have shown varied effects of engineered nanoparticles (ENPs) on plants; however, most of these studies focused on the interaction of NPs with plants at root level. The increasing production and use of NPs have also increased the atmospheric amounts of NPs, which could be taken up by plants through their leaves. Cucumbers (Cucumis sativus L.) are broad leaf plants commonly grown both commercially and in home vegetable gardens that can be easily impacted by atmospheric NPs. However, there is limited information about the potential effects of these atmospheric NPs on cucumber. This research was aimed to determine (I) the possible uptake and translocation of cerium (Ce) by cucumber plants exposed to nCeO 2 (cerium dioxide nanoparticles, nanoceria) through the foliage, (II) the impacts of the NPs on physiological parameters of the plants and the effects on the nutritional value and quality of the fruits, and (III) the effects of seven copper compounds/nanoparticles applied to the growth medium of lettuce (Lactuca sativa) and alfalfa (Medicago sativa). For aim I, 15 day-old hydroponically grown cucumber plants were exposed to nCeO2, either as powder at 0.98 and 2.94 g/m3 or suspensions at 20, 40, 80, 160, 320 mg/l. Ce uptake was analyzed by using inductively coupled plasma-optical emission spectroscopy (ICP-OES) and transmission electron microscope (TEM). The activity of three stress enzymes was measured by UV/Vis. Ce was detected in all cucumber tissues and TEM images showed the presence of Ce in roots. Results suggested nCeO2 penetrated plants through leaves and moved to other plant parts. The biochemical assays showed nCeO2 also modified stress enzyme activities. For aim II, 15 day-old soil grown cucumber plants were foliar treated, separately

  17. Sustainable domestic effluent reuse via Subsurface Drip Irrigation (SDI): alfalfa as a perennial model crop.

    PubMed

    Kazumba, Shija; Gillerman, Leonid; DeMalach, Yoel; Oron, Gideon

    2010-01-01

    Scarcity of fresh high-quality water has heightened the importance of wastewater reuse primarily in dry regions together with improving its efficient use by implementing the Subsurface Drip Irrigation (SDI) method. Sustainable effluent reuse combines soil and plant aspects, along with the maintainability of the application system. In this study, field experiments were conducted for two years on the commercial farm of Revivim and Mashabay-Sade farm (RMF) southeast of the City of Beer-Sheva, Israel. The purpose was to examine the response of alfalfa (Medicago sativa) as a perennial model crop to secondary domestic effluent application by means of a SDI system as compared with conventional overhead sprinkler irrigation. Emitters were installed at different depths and spacing. Similar amounts of effluent were applied to all plots during the experimental period. The results indicated that in all SDI treatments, the alfalfa yields were 11% to 25% higher than the ones obtained under sprinkler irrigated plots, besides the one in which the drip laterals were 200 cm apart. The average Water Use Efficiency (WUE) was better in all SDI treatments in comparison with the sprinkler irrigated plots. An economic assessment reveals the dependence of the net profit on the emitters' installation geometry, combined with the return for alfalfa in the market.

  18. Influence of exogenous application of glutathione on rubisco and rubisco activase in heavy metal-stressed tobacco plant grown in vitro

    PubMed Central

    Son, Jeong Ah; Narayanankutty, Damodaran Puthanveettil; Roh, Kwang Soo

    2013-01-01

    The effect of glutathione on the influences of heavy metals affecting rubisco and rubisco activase was studied in tobacco plants grown in vitro where the shoot explants of the tobacco plant cultured on MS medium under aseptic conditions and two explants were placed in the control, 0.1 mM GSH, 1 mM GSH, 0.2 mM Cd, 0.2 mM Cu, 0.2 mM Zn, and a mixture of Cd and GSH, Cu and GSH, Zn and GSH, respectively. The effect of GSH on the growth of the tobacco plant was minimal, but the heavy metals clearly retarded its growth. GSH recovered the growth retarded by heavy metals, and the concentration of GSH required to recover the growth differed depending on the heavy metals. The content of chlorophyll in the plant increased through GSH and Zn, and decreased through Cd and Cu. The chlorophyll content which decreased due to Cd and Cu was recovered by GSH, and the content which increased due to Zn was decreased by 1 mM GSH. The content of rubisco decreased due to GSH and heavy metals, and the content which decreased due to heavy metals was recovered by GSH, and when GSH was treated with Zn, the increased rate was maximum compared to other heavy metals. The activity of rubisco was increased due to GSH and heavy metals, and the activity increased by Cd and Zn decreased through GSH. In the case of Cu, the activity of GSH increased even more. There was no effect of GSH on the influences of heavy metals on the content and activity of rubisco activase. The activity of rubisco decreased by thiourea among six denaturing agents, and increased by l-cysteine, and in most cases the activity level was recorded as high. The activity of rubisco activase all decreased as a result of six denaturing agents, and the effect caused by EDTA and guanidine-HCl was the greatest, while the effect caused by l-cysteine and urea was minimal. PMID:24596504

  19. Selective enhancement of the fluorescent pseudomonad population after amending the recirculating nutrient solution of hydroponically grown plants with a nitrogen stabilizer.

    PubMed

    Pagliaccia, D; Merhaut, D; Colao, M C; Ruzzi, M; Saccardo, F; Stanghellini, M E

    2008-10-01

    Fluorescent pseudomonads have been associated, via diverse mechanisms, with suppression of root disease caused by numerous fungal and fungal-like pathogens. However, inconsistent performance in disease abatement, after their employment, has been a problem. This has been attributed, in part, to the inability of the biocontrol bacterium to maintain a critical threshold population necessary for sustained biocontrol activity. Our results indicate that a nitrogen stabilizer (N-Serve, Dow Agrosciences) selectively and significantly enhanced, by two to three orders of magnitude, the resident population of fluorescent pseudomonads in the amended (i.e., 25 microg ml(-1) nitrapyrin, the active ingredient) and recycled nutrient solution used in the cultivation of hydroponically grown gerbera and pepper plants. Pseudomonas putida was confirmed as the predominant bacterium selectively enhanced. Terminal restriction fragment length polymorphism (T-RFLP) analysis of 16S rDNA suggested that N-Serve selectively increased P. putida and reduced bacterial diversity 72 h after application. In vitro tests revealed that the observed population increases of fluorescent pseudomonads were preceded by an early growth suppression of indigenous aerobic heterotrophic bacteria (AHB) population. Interestingly, the fluorescent pseudomonad population did not undergo this decrease, as shown in competition assays. Xylene and 1,2,4-trimethylbenzene (i.e., the inert ingredients in N-Serve) were responsible for a significant percentage of the fluorescent pseudomonad population increase. Furthermore, those increases were significantly higher when the active ingredient (i.e., nitrapyrin) and the inert ingredients were combined, which suggests a synergistic response. P. putida strains were screened for the ability to produce antifungal compounds and for the antifungal activity against Pythium aphanidermatum and Phytophthora capsici. The results of this study suggest the presence of diverse mechanisms with

  20. Community Analysis of Root- and Tuber-Associated Bacteria in Field-Grown Potato Plants Harboring Different Resistance Levels against Common Scab

    PubMed Central

    Kobayashi, Akira; Kobayashi, Yuki Ohdaira; Someya, Nobutaka; Ikeda, Seishi

    2015-01-01

    Eight genotypes of potato plants with different resistance levels against common scab were grown in a field infested with Streptomyces turgidiscabies. DNA was extracted from the roots, tubers, and rhizosphere soils of each of the eight genotypes at the flowering stage, and the quantity of S. turgidiscabies genomic DNA was assessed by real-time PCR using a TaqMan probe. The results obtained showed that the different potato genotypes had significant impacts on the population levels of S. turgidiscabies between resistant and susceptible genotypes in the tubers, but not in the roots or rhizosphere soils. Clone analyses of 16S rRNA gene libraries from the eight potato genotypes identified three phyla (Proteobacteria, Firmicutes, and Actinobacteria) as dominant taxa in root and tuber clone libraries, while a clustering analysis identified 391 operational taxonomic units (OTUs) at the species level. Eleven OTUs closely related to Aquicella siphonis, Arthrobacter nicotinovorans, Streptomyces rishiriensis, Rhodococcus baikonurensis, Rhizobium radiobacter, Rhizobium etli, Phyllobacterium myrsinacearum, Paenibacillus pabuli, Paenibacillus alginolyticus, and Bacillus halmapalus were detected in the root or tuber libraries of all the potato genotypes examined. Furthermore, an abundance of OTUs related to Aquicella and Rhodococcus was observed in the rhizospheres of resistant and susceptible potato genotypes, respectively. Based on this ecological information, an efficient survey may be conducted for biological agents from the potato rhizosphere. PMID:26657303

  1. Root responses of Medicago truncatula plants grown in two different iron deficiency conditions: changes in root protein profile and riboflavin biosynthesis.

    PubMed

    Rodríguez-Celma, Jorge; Lattanzio, Giuseppe; Grusak, Michael A; Abadía, Anunciación; Abadía, Javier; López-Millán, Ana-Flor

    2011-05-06

    Iron deficiency is a yield-limiting factor with major implications for field crop production in one-third of the world's agricultural areas, especially those with high soil CaCO(3). In the present work, a two-dimensional gel electrophoresis proteomic approach was combined with a study on the riboflavin synthesis pathway, including qPCR and riboflavin determination, to investigate Fe-deficiency responses in Medicago truncatula plants grown with and without CaCO(3). Iron deficiency caused a de novo accumulation of DMRLs and GTPcII, proteins involved in riboflavin biosynthesis, as well as marked increases in root riboflavin concentrations and in the expression of four genes from the riboflavin biosynthetic pathway. Two novel changes found were the increased accumulation of proteins related to N recycling and protein catabolism. Other identified changes were consistent with previously found increases in glycolysis, TCA cycle, and stress-related processes. All effects were more marked in the presence of CaCO(3). Our results show that the riboflavin biosynthesis pathway was up-regulated at the genomic, proteomic, and metabolomic levels under both Fe-deficiency treatments, especially in the presence of CaCO(3). Results also indicate that N recycling occurs in M. truncatula upon Fe deficiency, possibly constituting an additional anaplerotic N and C source for the synthesis of secondary metabolites, carboxylates, and others.

  2. Is There a Genetic Basis for Fluctuating Asymmetry and Does it Predict Fitness in the Plant Lotus corniculatus Grown in Different Environmental Conditions?

    PubMed

    Andalo; Bazin; Shykoff

    2000-03-01

    Fluctuating asymmetry (FA) is considered to be a good measure of developmental stability. We measured the asymmetry of leaves and flowers of 16 different genotypes of Lotus corniculatus grown in four different experimental environments to estimate the plasticity or developmental stability of asymmetry itself. We found that an index of FA (absolute difference between size of left and right sides, corrected for trait size) differed significantly across environments, with the treatment CO2+/N+ inducing the greatest FA for both flowers and leaves. Genotypes did not differ in FAs. Individual plants showed significantly different FAs only for flowers. At the individual level, we found no significant relationship between flower FA and fitness. Previous work indicates that change in asymmetry in a poor or perturbing environment versus a good environment could reflect the intrinsic quality of a particular genotype. However, in our experiment, genotype effect was significant only for change in asymmetry of leaves, and this last trait was not significantly correlated with our fitness estimate for each genotype in either the most or the least perturbing environment.

  3. Effects of AN Alfalfa (medicago Sativa) Buffer Strip on Leached δ15NNITRATE Values: Implications for Management of Hydrologic N Losses

    NASA Astrophysics Data System (ADS)

    Kelley, C. J.; Keller, C. K.; Smith, J. L.; Evans, R. D.; Harlow, B.

    2011-12-01

    Buffer strips are commonly used to decrease agricultural runoff with the objective of limiting sediment and agrochemicals fluxes to surface waters. The objective of this study was to determine the effects of an alfalfa buffer strip on the magnitude and source(s) of leached nitrate from a dryland agricultural field. Previous research at the Cook Agronomy Farm has inferred two sources of nitrate in tile drain discharge, a high-discharge-season (January through May) synthetic fertilizer source, and a low-discharge-season (June through December) soil organic nitrogen source. This study examines how a change in management strategy and crop species alters the low discharge season nitrate source. In the spring of 2006 an alfalfa buffer strip approximately 20 m wide was planted running approximately north-south in the lowland portion of a 12 ha tile-drained field bordering a ditch that drains into Missouri Flat Creek. Three-year (2003 through 2005) average NO3--N flux prior to the planting of the alfalfa buffer strip was ~0.40 kg ha-1 year-1. After planting, the three-year (2006 through 2008) average NO3--N flux was ~0.38 kg ha-1 year-1. The lack of evident buffer-strip influence on the fluxes may be due in part to the large variation in precipitation amounts and timing that control water flows through the system. Three-year average δ15Nnitrate values for the tile drain pre and post planting of the alfalfa buffer strip were 6.9 ± 1.1 % and 4.2 ± 0.9 % respectively. We hypothesize that the significant difference indicates that the alfalfa strip affects the source of leached nitrate. Before planting the alfalfa buffer strip, the interpreted source of nitrate was mineralization of soil organic nitrogen from non-N2 fixing crops (spring and summer wheat varieties). After planting the alfalfa buffer strip, the source of nitrate was interpreted to be a mixture of mineralized soil organic nitrogen from N2 fixing alfalfa and non-N2 fixing crops. Further work is needed to test

  4. Down-regulation of specific members of the glutamine synthetase gene family in alfalfa by antisense RNA technology.

    PubMed

    Temple, S J; Bagga, S; Sengupta-Gopalan, C

    1998-06-01

    Glutamine synthetase (GS) catalyzes the ATP-dependent condensation of NH3 with glutamate to produce glutamine. In plants GS is an octameric enzyme and is located either in the cytoplasm (GS1) or in the chloroplast (GS2). Two distinct classes of GS1 genes with unique 3'-untranslated region (3'UTR) have been identified in alfalfa. We have demonstrated that the two classes exhibit differential expression pattern in the different plant organs suggesting different functional roles for the different isozymes. To determine the functional significance of the two classes of GS1 genes in alfalfa, we have utilized antisense gene constructs aimed specifically at the 3'UTR of the two GS1 genes and introduced them individually into alfalfa. Our data show that the gene constructs are effective in lowering the corresponding transcript level very effectively though there were organ-specific differences in the level of reduction. No transcript corresponding to the antisense gene construct was detected in any of the alfalfa transformants though they accumulated to significant levels in transgenic tobacco containing the same construct. This suggests that the antisense transcript was not stable in the presence of the homologous target sequence. Transgenic alfalfa with up to 80% reduction in the transcript level corresponding to each gene class, however, showed no reduction in GS activity or GS1 polypeptide level. The results suggest that GS1 mRNA levels are not rate-limiting for GS1 polypeptide synthesis and that GS levels are controlled both at the transcriptional and translational/post-translational level.

  5. Stress Responses in Alfalfa (Medicago sativa L.)

    PubMed Central

    Jorrin, Jesus; Dixon, Richard A.

    1990-01-01

    l-Phenylalanine ammonia-lyase has been purified from elicitor-treated alfalfa (Medicago sativa L.) cell suspension cultures using two protocols based on different sequences of chromatofocusing and hydrophobic interaction chromatography. Three distinct forms of the intact enzyme were separated on the basis of affinity for Octyl-Sepharose, with isoelectric points in the range pH 5.1 to 5.4. The native enzyme was a tetramer of Mr 311,000; the intact subunit Mr was about 79,000, although polypeptides of Mr 71,000, 67,000 and 56,000, probably arising from degradation of the intact subunit, were observed in all preparations. Two-dimensional gel analysis revealed the presence of several subunit isoforms of differing isoelectric points. The purified isoforms of the native enzyme had different Km values for l-phenylalanine in the range 40 to 110 micromolar, although mixtures of the forms in crude preparations exhibited apparent negative rate cooperativity. The enzyme activity was induced approximately 16-fold within 6 hours of exposure of alfalfa cells to a fungal elicitor or yeast extract. Analysis by hydrophobic interaction chromatography revealed different proportions of the different active enzyme isoforms, depending upon either time after elicitation or the elicitor used. The elicitor-induced increase in enzyme activity was associated with increased translatable phenylalanine ammonia-lyase mRNA activity in the polysomal fraction. Images Figure 4 Figure 7 PMID:16667296

  6. From model to crop: functional analysis of a STAY-GREEN gene in the model legume Medicago truncatula and effective use of the gene for alfalfa improvement.

    PubMed

    Zhou, Chuanen; Han, Lu; Pislariu, Catalina; Nakashima, Jin; Fu, Chunxiang; Jiang, Qingzhen; Quan, Li; Blancaflor, Elison B; Tang, Yuhong; Bouton, Joseph H; Udvardi, Michael; Xia, Guangmin; Wang, Zeng-Yu

    2011-11-01

    Medicago truncatula has been developed into a model legume. Its close relative alfalfa (Medicago sativa) is the most widely grown forage legume crop in the United States. By screening a large population of M. truncatula mutants tagged with the transposable element of tobacco (Nicotiana tabacum) cell type1 (Tnt1), we identified a mutant line (NF2089) that maintained green leaves and showed green anthers, central carpels, mature pods, and seeds during senescence. Genetic and molecular analyses revealed that the mutation was caused by Tnt1 insertion in a STAY-GREEN (MtSGR) gene. Transcript profiling analysis of the mutant showed that loss of the MtSGR function affected the expression of a large number of genes involved in different biological processes. Further analyses revealed that SGR is implicated in nodule development and senescence. MtSGR expression was detected across all nodule developmental zones and was higher in the senescence zone. The number of young nodules on the mutant roots was higher than in the wild type. Expression levels of several nodule senescence markers were reduced in the sgr mutant. Based on the MtSGR sequence, an alfalfa SGR gene (MsSGR) was cloned, and transgenic alfalfa lines were produced by RNA interference. Silencing of MsSGR led to the production of stay-green transgenic alfalfa. This beneficial trait offers the opportunity to produce premium alfalfa hay with a more greenish appearance. In addition, most of the transgenic alfalfa lines retained more than 50% of chlorophylls during senescence and had increased crude protein content. This study illustrates the effective use of knowledge gained from a model system for the genetic improvement of an important commercial crop.

  7. Transgenic expression of medicago truncatula PR10 and PR5 promoters in alfalfa shows pathogen-induced up-regulation of transgene expression

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genetic modification of alfalfa to introduce novel traits requires promoters for controlling gene expression. Promoters that are constitutively activated for expression of genes that enhance disease resistance pose a great energy load on the plant and exert a strong selective pressure on the pathoge...

  8. Environmental Impact Research Program: Alfalfa (Medicago sativa). Section 7.3.1, U.S. Army Corps of Engineers Wildlife Resources Management Manual.

    DTIC Science & Technology

    1986-07-01

    Ditterline et al. 1976, Hanson and Barnes 1978, Wasser 1982). ,’ - Plants are palatable and nutritious to most herbivores and provide good cover for many...I to 4 cm) long and 0.4 to 0.8 in. (I to 2 cm) wide. Small pea - like flowers range in color from pale blue to purple but are occasionally J . white or...se- vere damage. Lygus bugs and alfalfa seed chalcids affect seed production but are controllable by insecticides. The pea aphid and spotted alfalfa

  9. An algorithm for temperature correcting substrate moisture measurements: aligning substrate moisture responses with environmental drivers in polytunnel-grown strawberry plants

    NASA Astrophysics Data System (ADS)

    Goodchild, Martin; Janes, Stuart; Jenkins, Malcolm; Nicholl, Chris; Kühn, Karl

    2015-04-01

    The aim of this work is to assess the use of temperature corrected substrate moisture data to improve the relationship between environmental drivers and the measurement of substrate moisture content in high porosity soil-free growing environments such as coir. Substrate moisture sensor data collected from strawberry plants grown in coir bags installed in a table-top system under a polytunnel illustrates the impact of temperature on capacitance-based moisture measurements. Substrate moisture measurements made in our coir arrangement possess the negative temperature coefficient of the permittivity of water where diurnal changes in moisture content oppose those of substrate temperature. The diurnal substrate temperature variation was seen to range from 7° C to 25° C resulting in a clearly observable temperature effect in substrate moisture content measurements during the 23 day test period. In the laboratory we measured the ML3 soil moisture sensor (ThetaProbe) response to temperature in Air, dry glass beads and water saturated glass beads and used a three-phase alpha (α) mixing model, also known as the Complex Refractive Index Model (CRIM), to derive the permittivity temperature coefficients for glass and water. We derived the α value and estimated the temperature coefficient for water - for sensors operating at 100MHz. Both results are good agreement with published data. By applying the CRIM equation with the temperature coefficients of glass and water the moisture temperature coefficient of saturated glass beads has been reduced by more than an order of magnitude to a moisture temperature coefficient of

  10. Physico-chemical changes in dissolved organic matters in the rhizosphere of plants grown in soil amended with organic wastes: an in-situ investigation.

    NASA Astrophysics Data System (ADS)

    Djae, Tanalou; Bravin, Matthieu; Garnier, Cédric; Mayen, Jean-Fabien; Doelsch, Emmanuel

    2014-05-01

    In agricultural context, prerequisite condition to forecast trace metal phytodisponibility is to evaluate trace metal speciation in the rhizosphere solution, especially in soil amended with organic wastes. The most advanced trace metal speciation models (e.g. WHAM, NICA-DONNAN) take into account dissolved organic matter (DOM) reactivity toward trace metals. Generally, the scientific community uses, a fixed percentage of DOM reactivity, usually of 40 % to 80 %, to predict trace metal speciation. However, recent studies have demonstrated that the binding capacity of DOM towards trace metals is much larger than expected. The aim of our study was to investigate the mechanisms supporting the variability in DOM reactivity by assessing the physico-chemical changes of DOM in the bulk-soil and rhizosphere in context of agricultural recycling of organic wastes. An in-situ experiment was conducted in Reunion Island (Indian Ocean). Two plant species, i.e. a graminaceous species the fescue (Festuca rubra) and a dicotyledonous species the tomato (Lycopersicon esculentum), were grown on a soil where we applied two types of organic wastes (pig manure compost and poultry manure compost) at three rates and a mineral fertilizer. Following this experiment, the soil either adhering to the roots (i.e. rhizosphere) or not (i.e. bulk-soil) was sampled and the soil solution was recovered by chemical extraction. DOM concentration, total acidity and DOM fluorescence were measured. Root activities and organic wastes induced variations in the physico-chemical parameters of DOM. DOM concentration tended to increase in bulk-soil with increasing organic waste application rate. DOM concentrations measured in rhizosphere are significantly greater than those in the bulk-soil especially when organic wastes were applied to soil. Preliminary results allow us to observe a decrease in the density of carboxylic-like (pKa

  11. Removal of phenanthrene in contaminated soil by combination of alfalfa, white-rot fungus, and earthworms.

    PubMed

    Deng, Shuguang; Zeng, Defang

    2017-01-23

    The aim of this study was to investigate the removal of phenanthrene by combination of alfalfa, white-rot fungus, and earthworms in soil. A 60-day experiment was conducted. Inoculation with earthworms and/or white-rot fungus increased alfalfa biomass and phenanthrene accumulation in alfalfa. However, inoculations of alfalfa and white-rot fungus can significantly decrease the accumulation of phenanthrene in earthworms. The removal rates for phenanthrene in soil were 33, 48, 66, 74, 85, and 93% under treatments control, only earthworms, only alfalfa, earthworms + alfalfa, alfalfa + white-rot fungus, and alfalfa + earthworms + white-rot fungus, respectively. The present study demonstrated that the combination of alfalfa, earthworms, and white-rot fungus is an effective way to remove phenanthrene in the soil. The removal is mainly via stimulating both microbial development and soil enzyme activity.

  12. Calcium Nutrition and Resistance of Alfalfa to Ditylenchus dipsaci

    PubMed Central

    Sherwood, R. T.; Huisingh, D.

    1970-01-01

    Stem nematode-susceptible 'Atlantic' and resistant 'Lahontan' alfalfa seedlings, grown in sand and watered with complete nutrient solutions containing 0.75, 1.5, 3.0, 6.0, or 12.0 mM Ca⁺⁺/liter, were inoculated with Ditylenchus dipsaci (the stem nematode) 5-6 days after emergence. Approximately equal numbers of nematodes entered the tissues of each variety/Ca⁺⁺ concentration within 2 days. Penetration was reduced at 12 mM Ca⁺⁺/liter. Reproduction during 21 days following inoculation yielded 3-fold, or greater, nematode increases in 'Atlantic' buds at all Ca⁺⁺ concentrations, in 'Atlantic' cotyledons at the four lower concentrations, in 'Lahontan' buds at the lowest concentration and in 'Lahontan' cotyledons at the two lowest concentrations. Reproduction was lower at the higher Ca⁺⁺ concentrations. Increased nutrient Ca⁺⁺ concentrations resulted in increased Ca⁺⁺ conten