baccata seedlings acclimated: Topics by WorldWideScience.org

The Metabolism of the Germinating Oil Palm (Elaeis guineensis) Seedling 1

Increasing the Mg(2+) concentration results in a depression of succincoxidase-linked state 3

1978-01-01

Long- but not short-term heat acclimation produces an apoptosis-resistant cardiac phenotype: a lesson from heat stress and ischemic/reperfusion insults

The metabolism of ¹⁴C-labeled fatty acids and triacylglycerols was followed in intact germinating oil palm seedlings as well as in tissue slices. In the germinating seedling, the shoot contained...Full Text Available

1983-12-01

Fall Chinook Aclimation Project; Pittsburg Landing, Captain John Rapids, and Big Canyon, Annual Report 2001.

Long-term heat acclimation (AC, 30d/34°C) is a phenotypic adaptation leading to increased thermotolerance during heat stress (HS, 2 h 41°C). AC also renders protection against...Full Text Available

2010-09-01

Germination and Seedling Emergence of Ammannia coccinea as Influenced by Environmental Factors

Fisheries co-managers of U.S. v Oregon supported and directed the construction and operation of acclimation and release facilities for Snake River fall Chinook from Lyons Ferry Hatchery at three sites above Lower Granite Dam. In 1996, Congress instructed the U.S. Army Corps of Engineers (USCOE) to construct, under the Lower Snake River Compensation Plan (LSRCP), final rearing and acclimation facilities for fall Chinook in the Snake River basin to complement their activities and efforts in compensating for fish lost due to construction of the lower Snake River dams. The Nez Perce Tribe (NPT) played a key role in securing funding and selecting acclimation sites, then assumed responsibility for operation and maintenance of the facilities. In 1997, Bonneville Power Administrative (BPA) was directed to fund operations and maintenance (O&M) for the facilities. Two acclimation facilities, Captain John ...

2004-01-01

KoreaScience (Korea)

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2010-06-01

Effects of Simulated Acid Rain on Growth, Pigments and Leaf Surface Morphology of the Seedlings of Amaranthus tricolor L.

KoreaScience (Korea)

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1994-08-01

Short RNA half-lives in the slow-growing marine cyanobacterium Prochlorococcus

Acclimation of Two Tomato Species to High Atmospheric CO₂¹

BackgroundRNA turnover plays an important role in the gene regulation of microorganisms and influences their speed of acclimation to environmental changes. We investigated whole-genome...Full Text Available

2010-01-01

Proliferation and differentiation of brown adipocytes from interstitial cells during cold acclimation

Lycopersicon esculentum Mill. cv Vedettos and Lycopersicon chmielewskii Rick, LA 1028, were exposed to two CO₂ concentrations (330 or 900 microliters per...Full Text Available

1989-08-01

Labelling of "1"4C-M-ISP and its absorption, translocation and distribution in peanut and soybean seedling

The mechanisms of brown adipocyte proliferation and differentiation during cold acclimation (and/or adaptation to hyperphagia) have been studied by quantitative photonic radioautography. (/sup 3/H)thymidine was injected to warm-acclimated (25/sup 0/C) rats and to animals exposed to 5/sup 0/C for 2 days. Samples of interscapular brown adipose tissue were collected for quantitative analysis of mitotic frequencies at various periods of time (4 h-15 days) after the injection of (/sup 3/H)thymidine, the rats being maintained at the temperatures to which they were initially exposed. It was found that cold exposure for 2 days markedly enhanced mitotic activity in endothelial cells, interstitial cells, and brown preadipocytes rather than in fully differentiated brown adipocytes. The total tissue labeling index (percent of labeled nuclei) increased approx.70 times over control values. The authors now report that cellular labeling progressively increased ...

1986-06-01

Trade-offs Between Seedling Growth and Survival in Deciduous Broadleaved Trees in a Temperate Forest

Labelling of "1"4C-M-ISP and its absorption, translocation and distribution in peanut and soybean seedling were studied. The results of experiments showed that the radioactive substance could be translocated in xylem and phloem of two kinds of plants. The root of peanut seedling absorbed "1"4C-M-ISP from the nutrient solution more strong than the root of soybean seedling did. After leaf treatment with "1"4C-M-ISP, the soybean seedling absorbed more radioactive substance than peanut seedling did. But the translocation's speed of radioactive substance in pnloem of two kinds of plants were similar.

1990-01-01

Some Enzymic Activities in the Germinating Oil Palm (Elaeis guineensis) Seedling 1

Background and AimsIn spatially heterogeneous environments, a trade-off between seedling survival and relative growth rate may promote the coexistence of plant species. In temperate...Full Text Available

2007-03-01

Nitrate Reduction by Roots of Soybean (Glycine max [L.] Merr.) Seedlings

In germinating oil palm (Elaeis guineensis var D × P) seedling, an active lipase was present in the shoot but absent from both the kernel and the haustorium. It has an optimum...Full Text Available

1983-12-01

Ethylene-Induced Leaf Abscission in Cotton Seedlings ¹

Studies were conducted with 9 to 12 day-old soybean (Glycine max [L.] Merr. cv. Williams) seedlings to determine the contribution of roots to whole plant NO₃⁻...Full Text Available

1982-06-01

Effect of a Longitudinally Applied Voltage Upon the Growth of Zea mays Seedlings ¹

The speed of ethylene-induced leaf abscission in cotton (Gossypium hirsutum L. cv LG-102) seedlings is dependent on leaf position (i.e. physiological age). Fumigation...Full Text Available

1991-01-01

Cytoplasmic Calcium Increases in Response to Changes in the Gravity Vector in Hypocotyls and Petioles of Arabidopsis Seedlings1

The electrical parameters that affect young seedling growth were investigated. Voltages ranging from 5 to 40 volts were applied longitudinally along the mesocotyl region of 4-day old Zea mays...Full Text Available

1988-08-01

Auxins Induce Tryptophan Decarboxylase Activity in Radicles of Catharanthus Seedlings ¹

Plants respond to a large variety of environmental signals, including changes in the gravity vector (gravistimulation). In Arabidopsis (Arabidopsis thaliana) seedlings, gravistimulation...Full Text Available

2008-02-01

Asymmetric Distribution of Glucose and Indole-3-Acetyl-myo-Inositol in Geostimulated Zea mays Seedlings ¹

Germinating seedlings of Catharanthus roseus produce monoterpenoid indole alkaloids as a result of a transient increase of tryptophan decarboxylase (TDC) activity. The influence of...Full Text Available

1992-10-01

Genetic variability, heritability and genetic advance for seedling traits in sorghum genotypes

Indole-3-acetyl-myo-inositol occurs in both the kernel and vegetative shoot of germinating Zea mays seedlings. The effect of a gravitational stimulus on the transport...Full Text Available

1988-07-01

Vermicompost treatment differentially affects seed germination, seedling growth and physiological status of vegetable crop species

Analysis of data on seedling traits from 20 diverse genotypes revealed significant differences fro most of the seedling traits. Significant estimates of broad-sense heritability were observed for VI, ERI, FRTW, DRTW and R/S ratio. Genetic advance was maximum for VI,ERI and E%. The correlation of VI with ERI and R/S ratio was negative and significant, whereas it was positive and significant with E%, FSHW and DSHW. Characterization of the sorghum genotypes according to Anderson's Metro glyph Statistics revealed five different groups for seedling trails. (authors)

1999-01-01

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British Library Electronic Table of Contents (United Kingdom)

Vermicompost preparations are increasingly used in agricultural practice. There is a possibility, that crop plants are sensitive to negative effect of vermicompost at early stages of development. The aim of the present study was to test the effects of vermicompost on seed germination and seedling growth of different vegetable crop species. Vermicompost substitution inhibited seed germination and seedling growth with almost linear decrease of growth with increasing concentration of vermicopost in the substrate. However, both leaf chlorophyll content and photochemical activity of photosynthesis increased in all crop species with the exception of pea seedlings. Vermicompost extract as a watering solution showed positive effect on growth of bean and pea seedlings. Germination response of vermi...

2011-01-01

Diversity of Tropical Tree Seedling Responses to Drought

British Library Electronic Table of Contents (United Kingdom)

ABSTRACT Drought is an important seedling mortality agent in dry and moist tropical forests, and more severe and frequent droughts are predicted in the future. The effect of drought on leaf gas exchange and seedling survival was tested in a dry-down experiment with four tree species from dry and moist forests in Bolivia. Seedlings were droughted and wilting stage and gas exchange were monitored. Drought led to a gradual reduction of photosynthesis and stomatal conductance over time, whereas respiration and photosynthetic water-use efficiency initially increased with drought and then declined. Seedlings gradually went through the different wilting stages, until they eventually died, but the trajectory differed for the four species. The strong relationship between wilting stage and photosynt...

2007-01-01

Symbiotic regulation of plant growth, development and reproduction

Influence of some chemical compounds on germination and early seedling growth of two range species under allelopathic conditions

The growth and development of rice (Oryzae sativa) seedlings was shown to be regulated epigenetically by a fungal endophyte. In contrast to un-inoculated (nonsymbiotic) plants, endophyte...Full Text Available

2009-03-01

British Library Electronic Table of Contents (United Kingdom)

Seed priming technique has been known to improve germination and seedling emergence under different environment stresses. The objective of this study was to evaluate the effectiveness of seed priming in improving the seed germination and seedling vigor of Agropyron elongatum and Bromus inermis in response to five concentrations of the allelopathic extract of Thymus kotschyanus (0, 5%, 25%, 50% and 75%) under laboratory conditions. Pretreatments included gibberellic acid (250, 500 and 1000 ppm), potassium nitrate (0.1%, 0.2% and 0.3%) and salicylic acid (100, 200 and 300 mg/L). This experiment was carried out as a factorial experiment based on a completely randomized design with four replications. The results showed that seed germination, germination speed and seedling vigor were significan...

2011-01-01

PIXE analysis of trace elements in relation to chlorophyll concentration in Plantago ovata Forsk

Mutation breeding in kalmia juvenile trees derived from shoot tip cultare and kobus seedlings

Plantago ovata Forsk - an economically important medicinal plant - was analyzed for trace elements and chlorophyll in a study of the effects of gamma radiation on physiological responses of the seedlings. Proton-induced X-ray emission (PIXE) technique was used to quantify trace elements in unirradiated and gamma-irradiated plants at the seedling stage. The experiments revealed radiation-induced changes in the trace element and chlorophyll concentrations.

2010-03-15

Increased Endogenous Abscisic Acid Maintains Primary Root Growth and Inhibits Shoot Growth of Maize Seedlings at Low Water Potentials ¹

Juvenile trees of kalmia derived from shoot tip culture, and seedlings of kobus were irradiated with #gamma#-rays. In kalmia, two mutation lines were obtained which had narrowlong leaves. In kobus two mutation lines were obtained. One mutation line has flowers with 7 to 13 petals. Another mutation line has yellow-green variegated leaves. (author).

Rapid cold hardening increases cold and chilling tolerances more than acclimation in the adults of the sycamore lace bug, Corythucha ciliata (Say) (Hemiptera: Tingidae)

Roots of maize (Zea mays L.) seedlings continue to grow at low water potentials that cause complete inhibition of shoot growth. In this study, we have investigated the role of abscisic...Full Text Available

1990-08-01

British Library Electronic Table of Contents (United Kingdom)

The sycamore lace bug, Corythucha ciliata is a new, invasive pest of Platanus trees in China. Although C. ciliata is often subjected to acute low temperatures in early winter and spring in northern and eastern China, the cold tolerance of C. ciliata has not been well studied. The objectives of this study were to determine whether adults of C. ciliata are capable of rapid cold hardening (RCH), and to compare the benefits of RCH vs. cold acclimation (ACC) in the laboratory. When the adult females incubated at 26^oC were transferred directly to the discriminating temperature (-12^oC) for 2h, survival was only 22%. However, exposure to 0^oC for 4h before transfer to -12^oC for 2h induced RCH, i.e., increased survival to 68%. RCH could also be induced by gradual cooling of the insects at rates ...

2011-01-01

Boron-Dependent Degradation of NIP5;1 mRNA for Acclimation to Excess Boron Conditions in Arabidopsis.

Acclimation of tree function and structure to climate change and implications to forest carbon and nutrient balances

Boron (B) is an essential plant micronutrient that is toxic at higher levels. NIP5;1 is a boric acid channel required for B uptake and growth under B deficiency. Accumulation of the NIP5;1 transcript is upregulated under B deficiency in Arabidopsis thaliana roots. To elucidate the mechanism of regulation, the 5' untranslated region (UTR) of NIP5;1 was tested for its ability to confer B-dependent regulation using ?-glucuronidase and green fluorescent protein as reporters. This analysis showed that the 5' UTR was involved in NIP5;1 transcript accumulation in response to B conditions. We also found that high-B conditions trigger NIP5;1 mRNA degradation and that the sequence from +182 to +200 bp in the 5' UTR is required for this mRNA destabilization. In the nip5;1-1 mutant background, a NIP5;1 complementation construct without the 5' UTR produced high levels of mRNA accumulation, increased B concentrations in tissues, and reduced growth under high-B conditions. These data suggest that the ...

2011-09-01

Amelioration of phytotoxic effects of Cd on mung bean seedlings by gluconic acid secreting rhizobacterium Enterobacter asburiae PSI3 and implication of role of organic acid

Before large-scale anthropogenetic emissions the environmental factors have been rather stable for thousands of years, varying yearly, seasonally and daily in rather regular manners around some mean values. In this century the emissions of CO{sub 2}, sulphur and nitrogen from society to atmosphere are changing both atmospheric and soil environment at rates not experienced before. The fluxes to soil affect the contents of plant available nutrients and solubility of toxic compounds in the forest soil. Additionally, the chemical state of soil environment is coupled to tree growth, litter production and nutrient uptake as well as to the activity of biological organisms in soil, which decompose litter and release nutrients from it. Trees have developed effective regulation systems to cope with the environment during the evolution. The resulting acclimations improve the functioning of the trees if the environmental factors remain within their range of variation during ...

1996-12-31

British Library Electronic Table of Contents (United Kingdom)

Mung bean seedlings inoculated with Enterobacter asburiae PSI3, a gluconic acid-producing rhizosphere isolate, enhanced plant growth in the presence of phytotoxic levels of Cd2+ in gnotobiotic pot experiments as compared to the uninoculated Cd-treated plants. Addition of organic acids to Cd-stressed seedlings promoted root elongation. Hematoxylin competition assays showed that organic acids could displace Cd2+ from the Cd2+: hematoxylin complex in the same order of effectiveness as was found for restoration of root net elongation viz. oxalate?>?malate?>?succinate while gluconate was effective at higher concentrations. Root associated Cd2+, assessed by hematoxylin staining of roots was found to be reduced when roots were treated with organic acid. Cd stress increased antioxidant enzymes suc...

2008-01-01

Transport of Purine and Pyrimidine Bases and Nucleosides from Endosperm to Cotyledons in Germinating Castor Bean Seedlings 1

The Metabolism of Oat Leaves during Senescence

During germination and early growth of castor bean (Ricinus communis), all cellular constituents of the endosperm are eventually transferred to the growing embryo. The present results...Full Text Available

1983-10-01

Stimulation of Phosphatidylethanolamine Exchange by Castor Bean Cytosol Proteins ¹

When the detached first leaves of green or etiolated oat (Avena sativa cv. Victory) seedlings senesce in the dark, their oxygen consumption shows a large increase, beginning after 24...Full Text Available

1974-09-01

STIMPY mediates cytokinin signaling during shoot meristem establishment in Arabidopsis seedlings

Cytosol proteins prepared from castor bean endosperm (4-day-old) seedlings stimulate the exchange of [³H]phosphatidylethanolamine between liposomes and mitochondria. The acceleration of the...Full Text Available

1980-02-01

Proteinases and Enzyme Stability in Crude Extracts of Castor Bean Endosperm ¹

The establishment of the primary meristems through proliferation after germination is essential for plant post-embryonic development. Cytokinins have long been considered a key regulator of...Full Text Available

2010-02-15

Phytochrome-mediated Electric Potential Changes in Oat Seedlings ¹

The stability of catalase, fumarase, and isocitrate lyase from deliberately broken organelles in crude extracts from endosperm tissue of castor bean seedlings has been examined. These enzymes are relatively...Full Text Available

1981-03-01

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

Brief exposures to red light induce far red-reversible changes of 5 to 10 millivolts magnitude in the upper 1 centimeter of etiolated Avena coleoptiles. The changes begin within 15...Full Text Available

1972-12-01

Light and Dark Controls of Nitrate Reduction in Wheat (Triticum aestivum L.) Protoplasts ¹

Nitrogenase-dependent acetylene reduction, nodule function, and nodule regrowth were studied during vegetative regrowth of harvested (detopped) alfalfa (Medicago sativa L.) seedlings...Full Text Available

1979-07-01

Inhibitory Action of Auxin on Root Elongation Not Mediated by Ethylene

Protoplasts were isolated from the leaves of nitrate-cultured wheat (Triticum aestivum L. var. Frederick) seedlings. When incubated in the dark, protoplasts accumulated nitrite under...Full Text Available

1982-02-01

Diterpene Biosynthesis in Maize Seedlings in Response to Fungal Infection ¹

The inhibitory effects of indole-3-acetic acid (IAA) and 1-aminocyclopropane-1-carboxylic acid (ACC) on elongation growth of pea (Pisum sativum L.) seedling roots were investigated...Full Text Available

1989-09-01

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Dependency of Nitrate Reduction on Soluble Carbohydrates in Primary Leaves of Barley under Aerobic Conditions 1

A cell-free system which catalyzes the biosynthesis of terpene hydrocarbons when supplemented with mevalonate, Mn²⁺, and ATP was prepared from the scutellum-embryonic axis region of maize...Full Text Available

1979-09-01

Cumulative effects of protracted irradiation of Chernobyl exclusive zone plants

Nitrate reduction was studied as a function of carbohydrate concentration in detached primary leaves of barley (Hordeum vulgare L. cv Numar) seedlings under aerobic conditions in light...Full Text Available

1984-07-01

Cottonseed Malate Synthase ¹

The biological and radiobiological peculiarities of seeds and seedlings of the Rumex confertus and Lupinus polycolor plants, which grown during several generations in plots with different level of radionuclide pollution of the Chernobyl exclusive zone have been investigated.

2005-01-01

Characteristics of Galacturonic Acid Oligomers as Elicitors of Casbene Synthetase Activity in Castor Bean Seedlings 1

Malate synthase (EC 4.1.3.2), an enzyme unique to the glyoxylate cycle, was purified to homogeneity from cotyledons of 72-hours, darkgrown cotton (Gossypium hirsutum L.) seedlings....Full Text Available

1987-08-01

Biochemical Characterization of Soybean Mutants Lacking Constitutive NADH:Nitrate Reductase ¹

Partial digestion of polygalacturonic acid with polygalacturonase isolated from Rhizopus stolonifer produces a mixture of α-1,4-d-galacturonide oligomers which act...Full Text Available

1984-04-01

Auxin Biosynthesis during Seed Germination in Phaseolus vulgaris¹

Two nitrate reductase (NR) mutants were selected for low nitrate reductase (LNR) activity by in vivo NR microassays of M₂ seedlings derived from nitrosomethylurea-mutagenized...Full Text Available

1986-06-01

Abscisic Acid Inhibition of Radicle Emergence But Not Seedling Growth Is Suppressed by Sugars1

The relative roles of de novo biosynthesis of indoleacetic acid (IAA) and IAA conjugates stored in mature seeds (Phaseolus vulgaris L.) in supplying auxin to germinating bean seedlings...Full Text Available

1992-09-01

Propagation of jarrah (Eucalyptus marginata) by organ and tissue culture

Low concentrations of sugars altered the sensitivity of seed germination to inhibition by exogenous abscisic acid (ABA). Germination of wild-type and ABA-insensitive (abi) Arabidopsis...Full Text Available

2000-04-01

Nutrient dynamics and carbon partitioning in nutrient loaded Picea mariana [Mill.] B.S.P. seedlings during hardening

Micropropagation methods are described for the production of clonal lines from Eucalyptus marginata (jarrah) seedlings. Nodal explants from mature trees can also yield shoot cultures, but a high frequency of contamination occurs among such explants. Uncontaminated callus cultures can be produced from mature trees by culturing stamen filaments and shoots can subsequently be regenerated from this callus. The rooting percentage of shoot cultures from either nodes or stamen callus of mature trees is low compared with that from seedling explants. Considerable variation was observed between trees in the ability of stamen callus to regenerate shoots and in the frequency of rooting. (Refs. 27)

1982-01-01

Comparative cold resistance of three Columbia River organisms

Biomass and nutrient dynamics of black spruce seedlings during the hardening phase of the greenhouse rotation were examined after four pre-hardening fertilization regimes - conventional, constant-rate loading, exponential loading, and high exponential loading (delivering respectively 15, 40, 40 and 60 mg N seedling{sup -1}) - in order to assess nutrient dilution and steady-state nutrition. Although height growth of seedlings had virtually ceased during hardening, shoot biomass increased 99-142% and root biomass increased five- to tenfold depending on treatment. The biomass increase compromised steady-state nutrient status by diluting internal nutrient pools as nutrient supply was unable to keep up with growth. Soil nutrient levels were rapidly depleted during this period because of plant uptake and lack of fertilizer supplementation. Pre-hardening nutrient loading partly countered and delayed dilution effects, especially ...

1997-07-01

Mechanical wounding induces a nitrosative stress by down-regulation of GSNO reductase and an increase in S-nitrosothiols in sunflower (Helianthus annuus) seedlings

Resistance to abrupt and gradual cold shock was determined in bioassays with pumpkinseed (Lepomis gibbosus), rainbow trout (Salmo gairdneri), and a northwestern crayfish (Pacifastacus leniusculus) acclimated to higher temperatures at 5 C increments. Test criteria were median tolerance limits (TLm) for 96-h exposures after abrupt cold shock, and 50 percent loss of equilibrium (LE50) for decline rates of 18, 15, 10, 5, and 1 C/h during gradual cold shock. Cold resistance depended on original acclimation temperature (AT) and varied among species under both test conditions in the order: pumpkinseed less than rainbow trout less than crayfish. The lower TLm limit for pumpkinseed was 12.3 C at 30 C AT, 9.6 C at 25 C AT, 4.5 C at 20 C AT, and 2.7 C at 15 C AT. Rainbow trout at 20, 15 and 10 C AT survived abrupt exposures to cold down to 3.3, 1.4 and 0.5 C, respectively. Crayfish at 25, 20 and 15 C AT survived exposures down to 2.5, 0.4 and 0.0 C, ...

1977-03-01

British Library Electronic Table of Contents (United Kingdom)

Nitric oxide (NO) and related molecules such as peroxynitrite, S-nitrosoglutathione (GSNO), and nitrotyrosine, among others, are involved in physiological processes as well in the mechanisms of response to stress conditions. In sunflower seedlings exposed to five different adverse environmental conditions (low temperature, mechanical wounding, high light intensity, continuous light, and continuous darkness), key components of the metabolism of reactive nitrogen species (RNS) and reactive oxygen species (ROS), including the enzyme activities L-arginine-dependent nitric oxide synthase (NOS), S-nitrosogluthathione reductase (GSNOR), nitrate reductase (NR), catalase, and superoxide dismutase, the content of lipid hydroperoxide, hydrogen peroxide, S-nitrosothiols (SNOs), the cellular level of N...

2011-01-01

Ergosterol analyses of oil palm seedlings and plants infected with Ganoderma

British Library Electronic Table of Contents (United Kingdom)

Basal stem rot of oil palm (OP) by Ganoderma boninense is of major economic concern and it is the predominant disease of OP in SE Asia. Also, other plantation crops are affected by Ganoderma. The early detection of symptoms is crucial for control, although effective methods remain elusive. Ergosterol is the principal sterol of fungi and plays an essential role in the cell membrane and other cellular constituents. The analysis of ergosterol is useful for fungal detection in solid plant substrates. The present report compares ergosterol concentration in sound and decayed OP seedlings and mature plants using HPLC with diode array detection. The disease of OP requires to be considered as a white rot process where fungal biomass will increase from a low to high level as the infection progresses...

2011-01-01

Effects of fungicides on endophytic fungi and photosynthesis in seedlings of a tropical tree, guarea guidonia (meliaceae)

Differences in morphology, gas exchange and root hydraulic conductance before planting in Pinus canariensis seedlings growing under different fertilization and light regimes

Endophytes are microorganisms that live within healthy plant tissues, and include fungi and bacteria. They can be mutualists, comensals or even latent pathogens. Presence of these endosymbionts may affect host physiology, for example by consuming products of photosynthesis (endophytes are heterotrophs) or producing toxic metabolites. In this work two fungicides were used to eliminate fungal endophytes from seedlings of guarea guidonia. light saturated photosynthesis (Amax) was measured in endophytefree plants and compared with control plants. Each fungicide killed different fungal endosymbionts. phomopsis was more susceptible to benomyl while colletotrichum was more susceptible to propiconazole. Although suggestive, values of Amax were not significantly different for each treatment compared with control plants. No prediction can be made at this point about the final outcome of a given plantendophytic fungi interaction

2005-12-01

British Library Electronic Table of Contents (United Kingdom)

As the main forestry species in the Canary Islands (Spain), Pinus canariensis is frequently used in afforestation programs. Several nursery techniques are commonly employed to modify its morphology and physiology with the aim of improving post-planting survival and growth. In this work, we studied how fertilization and light regime treatments applied during the nursery period modify biomass allocation patterns and produce effects in gas exchange and root hydraulic conductance. Seedlings were grown for a 6-month period in the nursery under two light regimes (full sunlight and 40% PAR reduction), and three fertilization levels were applied in each light regime. Morphology, biomass allocation patterns, leaf gas exchange and hydraulic conductance of the whole root system were evaluated. Fertil...

2010-01-01

The Isolation and Partial Characterization of a Membrane Fraction Containing Phytochrome ¹²

The Decrease in Auxin Polar Transport Down the Lupin Hypocotyl Could Produce the Indole-3-Acetic Acid Distribution Responsible for the Elongation Growth Pattern

If 4-day-old dark-grown zucchini squash seedlings (Cucurbita pepo L. cv. Black Beauty) are exposed briefly to red light, subsequent cell fractionation yields about 40% of the total...Full Text Available

1974-09-01

Reducing Rice Seed Storage Protein Accumulation Leads to Changes in Nutrient Quality and Storage Organelle Formation¹^[W]^[OA]

The variation of indole-3-acetic acid (IAA) transport along Lupinus albus L. hypocotyls was studied using decapitated seedlings and excised sections. To confirm that the mobile species...Full Text Available

1992-09-01

Oxygen Inhibition of Nitrate Reductase Biosynthesis in Detached Corn Leaves via Inhibition of Total Soluble Protein Synthesis ¹

Rice (Oryza sativa) seed storage proteins (SSPs) are synthesized and deposited in storage organelles in the endosperm during seed maturation as a nitrogen source for germinating seedlings....Full Text Available

2010-12-01

Metabolism and Binding of ¹⁴C-Maleic Hydrazide ¹

Detached first leaves of 3-day-old corn seedlings (Zea mays L. W64AxW183E) were incubated with nitrate in air or 100% O₂ in the light. Nitrate accumulation in the leaves...Full Text Available

1989-11-01

Isolation and Initial Characterization of Constitutive Nitrate Reductase-Deficient Mutants NR328 and NR345 of Soybean (Glycine max) ¹

Maleic hydrazide (MH) is taken up by corn and pea seedling roots and bound to some material which is insoluble in 80% ethanol or 5% trichloroacetic acid. ¹⁴C-MH is stable metabolically; chromatography...Full Text Available

1970-01-01

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Induction of Porphyrin Synthesis in Etiolated Bean Leaves by Chelators of Iron ¹²

Two nitrate reductase deficient mutants of soybean (Glycine max [L.] Merr. cv Bragg) were isolated from approximately 10,000 M₂ seedlings, using a direct enzymic assay in...Full Text Available

1986-06-01

In vitro activation of sigma-aminolevulinate dehydratase from far-red irradiated radish (Raphanus sativus L. ) seedlings by thioredoxin f

Primary leaves of 7- to 9-day-old etiolated seedlings of Phaseolus vulgaris L. var. Red Kidney infiltrated in darkness with aqueous solutions of α, α′-dipyridyl,...Full Text Available

1974-02-01

In Vivo Determination of Parameters of Nitrate Utilization in Wheat (Triticum aestivum L.) Seedlings Grown with Low Concentration of Nitrate in the Nutrient Solution ¹

sigma-Aminolevulinate dehydratase has been found to be activated in vitro by dithiotreitol and factors isolated from radish cotyledons grown under continuous far-red light. Cross experiments, between fructose 1-6 bisphosphatase system, and sigma-aminolevulinate dehydratase, show that these factors are functionally identical to thioredoxin f.

1983-10-01

Overexpression of a maize dehydrin gene, ZmDHN2b, in tobacco enhances tolerance to low temperature

Six genotypes of winter wheat (Triticum aestivum L.) differing in grain protein concentration were grown on a nutrient solution containing low concentrations of NO₃⁻...Full Text Available

1981-12-01

British Library Electronic Table of Contents (United Kingdom)

Dehydrins, a subfamily of group 2 LEA proteins, are intrinsically unstructured plant proteins that accumulate in the late stages of seed development and in vegetative tissues subjected to water deficit, salinity, low temperature, or abscisic acid treatment. In this study, we isolated and characterized ZmDHN2b, a maize dehydrin gene. The genomic organization of the ZmDHN2b gene and its expression in maize seedlings were analyzed. To investigate the function of ZmDHN2b, we generated transgenic tobacco plants constitutively overexpressing ZmDHN2b. Ectopic expression of ZmDHN2b in tobacco accelerated seed germination and seedling growth at 15?C. Furthermore, ZmDHN2b-overexpressing lines had lower levels of cold-induced malondialdehyde and less electrolyte leakage than wild-type tobacco at 4?C....

2011-01-01

Flows for Floodplain Forests: A Successful Riparian Restoration

Vegetation re-establishment on a hardwood forest site denuded by brine

This peer-reviewed article from Bioscience journal is about restoring the Truckee river.Throughout the 20th century, the Truckee River that flows from Lake Tahoe into the Nevada desert was progressively dammed and dewatered, which led to the collapse of its aquatic and riparian ecosystems. The federal designation of the endemic cui-ui sucker (Chasmistes cujus) as endangered prompted a restoration program in the 1980s aimed at increasing spring flows to permit fish spawning. These flows did promote cui-ui reproduction, as well as an unanticipated benefit, the extensive seedling recruitment of Fremont cottonwood (Populus fremontii) and sandbar willow (Salix exigua). Recruitment was scattered in 1983 but extensive in 1987, when the hydrograph satisfied the riparian recruitment box model that had been developed for other rivers. That model was subsequently applied to develop flow prescriptions that were implemented from 1995 through 2000 and enabled further ...

2003-07-01

Propagation of jarrah (Eucalyptus marginata) by organ and tissue culture

Brine from active oil wells seeped through the soil of a forested site in north-western Pennsylvania and killed all vegetation in its path, leaving the affected area unproductive and unsightly. After the brine source was eliminated, herbaceous plants, shrubs and forest tree seedlings became established and developed rapidly. Establishment began in the first year and by Year 4 the site had developed into a healthy young forest. Results show that Allegheny hardwood forest sites damaged by brine water will rapidly revegetate once the brine water discharge is stopped if there is a seed supply and if the area is fenced to exclude deer. 3 figs., 12 refs.

1989-04-01

Proceedings of the third annual better reclamation with trees conference

Methods are described for the production of callus and subsequent shoot and root induction and multiplication using stamen filaments, nodes of young stems of mature trees or cotyledon petioles. A high frequency of contamination occurred using nodal sections from mature trees, whereas up to 100% sterility was obtained with cotyledons and stamens. The rooting % of shoot cultures from nodes or stamen callus was low compared with that of shoots from seedling callus. Considerable variation was observed between clones from different trees in their ability to produce shoots and roots. 27 references

1982-01-01

Effect of synthetic detergents on germination of fern spores

The twenty-three papers presented at this conference discussed requirements of land reclamation under the Federal surface mining regulations, evaluation techniques for assessing reclaimed land, spoil bank chemistry and its change with time, establishment techniques (vegetative propagation, containerized seedlings, nurse vegetation, nitrogen-fixing tree species, direct seeding, and general cultivation techniques), and results from early land reclamation trials. Twenty-two papers have been abstracted separately. 291 references, 16 figures, 80 tables.

1983-01-01

Clones to replace forest seedlings

Synthetic detergents constitute one of the most important water pollutants by contaminating the lakes and rivers through domestic and industrial use. Considerable information is now available for the adverse effects of detergents an aquatic fauna including fish, algae, and higher aquatic plants. Marked inhibition of germination in orchids and brinjals and of seedlings growth in raddish suggest that rapidly growing systems could be sensitive to detergent polluted water. The present study of the effect of linear alkyl benzene sulphonate on germination of the spores of a fern, Diplazium esculentum aims at the understanding of the effects of water pollution on pteridophytes and the development of spore germination assay for phytoxicity evaluation.

1986-12-01

Tissue culture and micropropagation for forest biomass production

A considerable time can elapse between initial selection of candidate plus trees and harvest of improved seed. The technique showing the greatest promise of shortening this interval is vegetative propagation. Stock plants are grown for two years from seed before the first propagation cycle begins and each plant can be bulked-up 300-500 times over two cycles. An initial stock of 2500 superior Sitka Spruce plants can be multiplied to yield between 300,000 and 750,000 rooted cuttings for forest use within four years from the start of propagation.

1985-01-01

The enhanced genomic instability was induced by alpha particle and low-energy ion irradiation in somatic cells of Arabidopsis thaliana

An increase in forest production will be necessary in the future when wood becomes a major renewable source of energy and chemicals along with its traditional role of fibre source. This increase could eventually by achieved be proper selection and breeding of trees. Clonal forestry by vegetative propagation of cuttings is becoming a viable alternative to a seedling-based forestry with many advantages, and cutting could be used to quickly propagate large numbers of clones of control-pollinated seedlings. Most forest trees are propagated sexually and seed orchards were started in the US and Canada in the last 40-50 years for breeding purposes. Forests could ultimately be established with improved seedlings instead of from seed with unknown genetic potential, or by natural regeneration. Micropropagation is the term used to refer to the propagation of plants raised by tissue culture methods rather than from seeds or cuttings. ...

1984-09-01

The role of acid incubation in rapid immobilization of hydrogen-producing culture in anaerobic upflow column reactors

Although low-energy ion radiation has been proven to have a wide range of biological effects and led to fruitful achievements as a new mutagenic source for genetic modification, there still exist some disputes about its mutagenic mechanisms because of its short-penetrating property. In present research, Arabidopsis thaliana transgenic for GUS recombination substrate was used to evaluate the genomic instability induced by irradiations of alpha particle (3.3MeV) and Low-energy-Argon ion (30 KeV). A pronounced effects of alpha particle irradiation to Arabidopsis thaliana seedlings and Argon ion irradiation to seeds on the somatic homologous recombination frequency (sHRF) were reported. The sHRFs increased 1.88-fold and 2.42-fold, respectively, which indicated that the short-penetrating radiation could effectively induce the plant genomic instability in either dry seeds or seedlings with active metabolism. The local alpha particle irradiation of ...

2008-08-12

Reproductive status influences the survival of new cells in the dentate gyrus of adult male meadow voles.

An approach of acidification was examined on formation of hydrogen-producing granules and biofilms in upflow column-shaped reactors. The reactors were fed with synthetic glucose wastewater and operated at 37 C and pH 5.5. The acclimated anaerobic culture was inoculated in four reactors designated R1, R2, R3 and R4, with R3 and R4 filled with granular activated carbon as support medium. To unveil the roles of acidification, microbial culture in R2 and R3 was subject to an acid incubation for 24 h by shifting the culture pH from 5.5 to 2.0. The experimental results suggested that the acidification substantially accelerated microbial granulation, but not biofilm formation. Microbial activities were inhibited by the acid incubation for about 78 h, resulting in the retarded formation of biofilms of the acidified culture. Reducing culture pH resulted in improvement in cell surface physicochemical properties favoring microbial adhesion and immobilization. Zeta potential ...

2008-10-15

A field demonstration of the microbial treatment of sour produced water

Reproductive status influences cell proliferation and the survival of new cells in the dentate gyrus of adult laboratory-reared and wild female meadow voles; reproductively inactive (RI) females have more proliferating cells and more labeled cells that survive 5 weeks vs. 2 h than reproductively active (RA) females. However, the effect of season has only been studied in a wild sample of male meadow voles and factors such as age and experience that have been shown to influence neurogenesis in the dentate gyrus of adult mammals cannot be controlled in a wild sample. Therefore, we investigated whether reproductive status regulates neurogenesis (cell proliferation and/or the survival of new cells) in the dentate gyrus of laboratory-reared adult male meadow voles so that confounding variables could be controlled. Males were acclimated to a short- or a long-photoperiod to simulate the non-breeding or breeding season, respectively, and reproductive status was verified by ...

2003-07-31

Responses of hybrid poplar clones and red maple seedlings to ambient O_3 under differing light within a mixed hardwood forest

The potential for detoxification and deodorization of sulfide-laden water (sour water) by microbial treatment was evaluated at a petroleum production site under field conditions. A sulfide-tolerant strain of the chemautotroph and facultative anaerobe, Thiobacillus denitrificans, was introduced into an oil-skimming pit of the Amoco Production Company LACT 10 Unit of the Salt Creek Field, Wyoming. Field-produced water enters this pit from the oil/water separation treatment train at an average flowrate of 5,000 bbl/D (795 m{sup 3}/D) with a potential maximum of 98,000 bbl/D (15,580 m{sup 3}/D). Water conditions at the pit inlet are 4,800 mg/l TDS, 100 mg/l sulfide, pH 7.8, and 107{degrees}F. To this water an aqueous solution of ammonium nitrate and diphosphorous pentoxide was added to provide required nutrients for the bacteria. The first 20% of the pit was aerated to a maximum depth of 5 ft (1.5 m) to facilitate the aerobic oxidation of sulfide. No provisions for pH control or biomass ...

1995-12-31

Photobiology and photosynthesis

The responses of ramets of hybrid poplar (Populus spp.) (HP) clones NE388 and NE359, and seedlings of red maple (Acer rubrum, L.) to ambient ozone (O_3) were studied during May-September of 2000 and 2001 under natural forest conditions and differing natural sunlight exposures (sun, partial shade and full shade). Ambient O_3 concentrations at the study site reached hourly peaks of 109 and 98 ppb in 2000 and 2001, respectively. Monthly 12-h average O_3 concentrations ranged from 32.3 to 52.9 ppb. Weekly 12-h average photosynthetically active radiation (PAR) within the sun, partial shade and full shade plots ranged from 200 to 750, 50 to 180, and 25 to 75 #mu#mol m"-"2 s"-"1, respectively. Ambient O_3 exposure induced visible foliar symptoms on HP NE388 and NE359 in both growing seasons, with more severe injury observed on NE388 than on NE359. Slight foliar symptoms were observed on red maple seedlings during the 2001growing season. Percentage of ...

2004-07-01

British Library Electronic Table of Contents (United Kingdom)

To test the hypothesis that leaf level photosynthetic related traits might confer late successionals a competitive advantage over early successionals in low light growth conditions, steady photosynthetic assimilation and dynamic photosynthetic induction related traits were examined in low light grown seedlings with contrasting successional status. Compared with the early successionals, late successionals as a group significantly exhibited lower leaf gas exchange rates. While late successionals required a longer time to respond to simulated sunflecks, they had lower rates of induction losses after sunflecks. Such photosynthetic induction traits allowed late successionals to more effectively utilize subsequent sunflecks. It was observed that plants with lower gas exchange rates responded mor...

2011-01-01

Identification of Semiochemicals Released by Cotton, Gossypium hirsutum, Upon Infestation by the Cotton Aphid, Aphis gossypii

British Library Electronic Table of Contents (United Kingdom)

The cotton aphid, Aphis gossypii (Homoptera: Aphididae), is increasing in importance as a pest worldwide since the introduction of Bt-cotton, which controls lepidopteran but not homopteran pests. The chemical ecology of interactions between cotton, Gossypium hirsutum (Malvaceae), A. gossypii, and the predatory lacewing Chrysoperla lucasina (Neuroptera: Chrysopidae), was investigated with a view to providing new pest management strategies. Behavioral tests using a four-arm (Pettersson) olfactometer showed that alate A. gossypii spent significantly more time in the presence of odor from uninfested cotton seedlings compared to clean air, but significantly less time in the presence of odor from A. gossypii infested plants. A. gossypii also spent significantly more time in the presence of heads...

2011-01-01

Growth promotion and induction of resistance in tomato plant against Xanthomonas euvesicatoria and Alternaria solani by Trichoderma spp.

British Library Electronic Table of Contents (United Kingdom)

In tomato crop, the induction of resistance emerges as an important alternative for achieving the reduction of chemicals in disease control. This study aimed to evaluate the ability of 28 Trichoderma isolates to promote the growth of tomato seedlings and to induce systemic resistance (ISR) against Xanthomonas euvesicatoria and Alternaria solani, the causal agents of bacterial spot and early blight, respectively. Twelve isolates promoted the increase of plant dry matter mass (DMM) above 100%, showing the great potential of these strains. All isolates were able to colonize the root system of tomato plants. The plant growth-promoting isolates were further evaluated for potential elicitation of ISR. Treatment of the soil with all Trichoderma isolates provided protection in tomato plants from 2...

2011-01-01

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Effects of acute and chronic gamma irradiation on the shoot apex and general morphology of Lupinus albus L

Changes in Energy Metabolism and Antioxidant Defense Systems During Seed Germination of the Weed Species Ipomoea triloba L. and the Responses to Allelochemicals

Lupinus albus L. plants were grown from seeds and irradiated at various stages of development with acute or chronic gamma rays. All plants were greenhouse grown (pre- and post-irradiation) and allowed to proceed through their normal growth cycle. The purpose of these experiments was to establish a Plactochron Index for Lupinus albus L. and to determine the effects of acute and chronic irradiation on development at the macro and microscopic levels. A Plastochron Index was calculated and used as an indirect time scale to evaluate the effects of gamma rays from a common base line. Acute radiation treatment lasted for a period of a few days, whereas chronic treatment was initiated at the seedling stage and lasted for the entire growth season. Vegetative plants were used to study the effects of acute radiation exposure on apical meristem morphology, Plastochron Index, phyllatoxis and gross morphology.

1980-01-01

British Library Electronic Table of Contents (United Kingdom)

The relationships between changes in energy metabolism and the antioxidant defense system in the weed species Ipomoea triloba L. during seed germination and early seedling growth were investigated. The effects of some common allelochemicals on these parameters also were studied. Respiratory activity and the activities of alcohol dehydrogenase, superoxide dismutase, catalase, guaicol peroxidase, ascorbate peroxidase, glutathione reductase, and lipoxygenase were measured. Mitochondrial oxidative phosphorylation resumed shortly after the seed imbibition period, as indicated by considerable KCN-sensitive respiratory activity in embryos of I. triloba. The occurrence of superoxide dismutase, catalase, guaicol peroxidase, and lipoxygenase activities in the embryos, along with significant KCN-inse...

2011-01-01

Abscisic Acid in Soil Facilitates Community Succession in Three Forests in China

British Library Electronic Table of Contents (United Kingdom)

Plants release secondary metabolites into the soil that change the chemical environment around them. Exogenous abscisic acid (ABA) is an important allelochemical whose role in successional trajectories has not been examined. We hypothesized that ABA can accumulate in the soil through successional processes and have an influence on forest dynamics. To this end, we investigated the distribution of ABA in forest communities from early to late successional stages and the response of dominant species to the gradient of ABA concentrations in three types of forests from northern to southern China. Concentrations of ABA in the soils of three forest types increased from early to late successional stages. Pioneer species? litters had the lowest ABA content, and their seed germination and seedling ea...

2011-01-01

Up-regulation of sucrose metabolizing enzymes in Oncidium goldiana grown under elevated carbon dioxide

Improved salt tolerance and seed cotton yield in cotton (Gossypium hirsutum L.) by transformation with betA gene for glycinebetaine synthesis

Experiments were conducted in controlled growth chambers to evaluate how increase in CO{sub 2} concentration affected sucrose metabolizing enzymes, especially sucrose phosphate synthase (SPS; EC 2.4.1.14) and sucrose synthase (SS; EC 2.4.1.13), as well as carbon metabolism and partitioning in a tropical epiphytic orchid species (Oncidium goldiana). Response of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco; EC 4.1.1.39) to elevated CO{sub 2} was determined along with dry mass production, photosynthesis rate, chlorophyll content, total nitrogen and total soluble protein content. After 60 days of growth, there was a 80% and 150% increase in dry mass production in plants grown at 750 and 1100 {mu} l{sup -}1 CO{sub 2}, respectively, compared with those grown at ambient CO{sub 2} (about 370 {mu} l{sup -}1). A similar increase in photosynthesis rate was detected throughout the growth period when measured under growth CO{sub 2} conditions. Concomitantly, there was a decline in leaf ...

2001-07-01

British Library Electronic Table of Contents (United Kingdom)

Homozygous transgenic cotton (Gossypium hirsutum L.) plants that accumulated glycinebetaine (GB) in larger quantities were more tolerant to salt than wild-type (WT) plants. Four transgenic lines, namely 1, 3, 4, and 5, accumulated significantly higher levels of GB than WT plants did both before and after salt stress. At 175 and 275?mM NaCl, seeds of all the transgenic lines germinated earlier and recorded a higher final germination percentage, and the seedlings grew better, than those of the WT. Under salt stress, all the lines showed some characteristic features of salt tolerance, such as higher leaf relative water content (RWC), higher photosynthesis, better osmotic adjustment (OA), lower percentage of ion leakage, and lower peroxidation of the lipid membrane. Levels of endogenous GB in ...

2011-01-01

Biological control of take-all in wheat by endophytic Bacillus subtilis E1R-j and potential mode of action

British Library Electronic Table of Contents (United Kingdom)

The bacterial strain E1R-j, isolated as an endophyte from wheat roots, exhibited high antifungal activity to Gaeumannomyces graminis var. tritici (Ggt). Strain E1R-j was identified as Bacillus subtilis based on morphological, physiological and biochemical methods as well as on 16S rDNA analysis. This strain inhibited mycelium growth in vitro of numerous plant pathogenic fungi, especially of Ggt, Coniothyrium diplodiella, Phomopsis sp. and Sclerotinia sclerotiorum. In greenhouse experiments, soil drenches with cell densities of 106, 109 and 1012CFU ml-1 E1R-j reduced significantly take-all disease, caused by Ggt, in wheat seedling by 62.6%, 68.6% and 70.7%, respectively, compared to the inoculated control, 4weeks after sowing. Growth parameters such as lengths and fresh weights of roots and...

2009-01-01

On the impact of low power density microwaves in some living tissues

["3H]Indole-3-acetyl-myo-inositol hydrolysis by extracts of Zea mays L. vegetative tissue

The biomedical and ecological interest for the microwave impact on the Earth biosphere is continuously increased since the industrial, military and communication activities strongly contribute to the electromagnetic stress of living bodies. In the next the authors present some of the main results obtained regarding the microwave exposure of various types of biological material: bacteria, fungi, young plant seedlings, dry seeds, animal tissues. The electromagnetic exposure was carried out in open space in well controlled environmental conditions by using 10.75 GHz/1 m W cm{sup -2} microwaves. Biochemical assays and cytogenetic tests have been carried out to reveal the changes induced post irradiation. The response of some pathogen bacteria, have been emphasized by means of turbidimetric measurements - the stimulatory effect being noticed at the level of the microbial population density (the stimulation of the human body microbial flora seems to be one of the side ...

2006-07-01

Vegetative propagation of hybrid aspen by bud grafting

["3H]Indole-3-acetyl-myo-inositol was hydrolyzed by buffered extracts of acetone powders prepared from 4 day shoots of dark grown Zea mays L. seedlings. The hydrolytic activity was proportional to the amount of extract added and was linear for up to 6 hours at 37"0C. Boiled or alcohol denatured extracts were inactive. Analysis of reaction mixtures by high performance liquid chromatography demonstrated that not all isomers of indole-3-acetyl-myo-inositol were hydrolyzed at the same rate. Buffered extracts of acetone powders were prepared from coleoptiles and mesocotyls. The rates of hydrolysis observed with coleoptile extracts were greater than those observed with mesocotyl extracts. Active extracts also catalyzed the hydrolysis of esterase substrates such as #alpha#-naphthyl acetate and the methyl esters of indoleacetic acid and naphthyleneacetic acid. Attempts to purify the indole-3-acetyl-myo-inositol hydrolyzing activity by chromatographic procedures resulted in ...

Translocation of /sup 14/C-sucrose from mesophyll to vein and stem bark in mulberry plant

Results are presented of trials in W. Germany involving Populus tremula X P. tremuloides. In a nursery in late August - early September 1971, some 1300 buds from 38 selected 3-yr-old hybrid aspen seedlings were grafted into T-slits at nodes 10-20 cm above root' collars of 1 and a half yr-old hybrid aspen stock (products of controlled crossings, and in some cases of similar parentage to the transplanted buds). In spring 1972, each stock (from which its own buds were removed) was cut back to a 'peg' 15-20 cm above the level of the graft; the 'peg' was later used to support the new shoot developed from the transplanted bud. By Sept. 1972, 33% of grafts were successful, the success rate being significantly different (3-67%) within clones; average height of scion shoots ranged from 79 to 375 cm (no significant difference between clones). In spring 1973, some 190 grafts from 35 clones were row-planted in the open (3 m between ...

1982-01-01

The effect of elevated carbon dioxide on a Sierra-Nevadan dominant species: Pinus ponderosa

One-year-old seedlings of mulberry, the variety of Shinichinose, were used to fix /sup 14/CO/sub 2/ for 10 minutes under light of 18,000 lux at 28 deg C. Photosynthesis was continued after that in the air not containing /sup 14/CO/sub 2/. The specimens were collected immediately after and 10 and 30 minutes after the /sup 14/CO/sub 2/ fixation, divided into mesophyll, vein and stem bark, frozen in liquid N/sub 2/, and the contents of sucrose, glucose and fructose and their radioactivity were measured. The ratio of the radioactivity incorporated into sucrose to the total radioactivity incorporated into each tissue was very large, and the incorporation into glucose or fructose was very little. The content of sucrose was also larger than that of the other sugars in all the tissues. These findings showed that the photosynthates were translocated mainly in the form of sucrose. The ratio of specific radioactivity (dpm/mg sugar) in the mesophyll to that in the vein was ...

1982-12-01

Soil chemistry and nutrition of North American spruce-fir stands: Evidence of recent change

The impact of increasing atmospheric C0{sub 2} has not been fully evaluated on western coniferous forest species. Two year old seedlings of Pinusponderosa were grown in environmentally controlled chambers under increased C0{sub 2} conditions for 6 months. These trees exhibit morphological, physiological, and biochemical alterations when compared to our controls. Analysis of whole plant biomass distribution has shown no significant effect to the root to shoot ratios, however needles subjected to elevated C0{sub 2} exhibited an increased overall specific needle mass and a decreased total needle area. Morphological changes at the needle level included decreased mesophyll to vascular tissue 91 ratio and variations in starch storage in chloroplasts. The elevated CO{sub 2} increased internal CO{sub 2} concentrations and assimilation of carbon. Biochemical assays revealed that ribulose-bisphosphate carboxylase specific activities increased on per unit area basis with ...

1995-01-01

Primary study on lesion mimic mutants of rice (oryza sativa L.)

One set of hypotheses offered to explain the decline of red spruce (Picea rubens Sarg.) in eastern North America focuses on the effect of acidic deposition on soil chemistry changes that may affect nutrient availability and root function. Long-term soils data suggests that soil acidification has occurred in some spruce stands over the past 50 yr, with plant uptake and cation leaching both contributing to the loss of cations. Studies of tree ring chemistry also have indicated changes in Ca/Al and Mg/Al ratios in red spruce wood, suggesting increases in the ionic strength of soil solution. Irrigation studies using strong acid inputs have demonstrated accelerated displacement of base cations from upper horizons. Spruce-fir (Abies spp.) nutrient budgets indicate that current net Ca and Mg leaching loss rates are of the same order of magnitude as losses to whole tree harvest removals, spread out over a 50-yr rotation. For most cations, red spruce foliar nutrient levels decline with ...

Physiological responses of Pinus sylvestris to changing carbon dioxide and ozone concentrations

Nineteen lesion mimic mutants (xsl1-19) of japonica rice Xiushui11 were obtained by ?-rays irradiation treatment. All mutants belonged to whole life lesion mimic. Lesion mimic of mutants didn't largen after tillering stage, leaves didn't wither, and no effect on the plants exsert spikes and seed. When the highest temperature in day exceeded 32 degree C in seedling stage, lesion mimic of all mutant expect xsl19 disappeared. Under 32 degree C, lesion mimic would appear gradually, and symptoms weren't inhibited by high temperature after 5 leaf stage. The plant heights of all lesion mimic mutants were 47.56-63.54 cm in the tillering stage, and that of CK was 83.75 cm; but the dwarf phenomenon of mutants only appeared before tillering stage, and didn't affect plant heights finally; the heading dates of mutants were the same to the CK, the ear length of all mutants were 9.43-15.19 cm, and that of CK was 16.41 cm; the total grain quantity per spike of all mutants were ...

2007-08-01

Natural vegetation at the proposed Reference Repository Location in southeastern Washington

The objective of this research is to study the effects of elevated ozone, carbon dioxide and their combination on ultrastructural, physiological and biochemical responses of Scots pine needles and how these effects are reflected to photosynthesis, carbohydrate and nutrient allocation and finally to shoot and root growth of trees. In addition the interactions of the studied trees and mycorrhizal fungi as well as insect herbivores are studied. The exposures have been running only for two growing periods and it seems necessary to continue the experiment over the third growing season in 1996. Since the analyses are partially incomplete, only preliminary conclusions are possible at the moment. The slightly increased shoot growth and needle width and increased amount of starch in chloroplasts point to the slight stimulating effect of elevated CO{sub 2} among the chamber treatments. Altogether the growth of the seedlings was best in the chamberless treatment indicating a ...

1996-12-31

Induced mutation in narrow-leafed lupin improvement: An example of herbicide tolerance

The dominant shrubs were sagebrush and spiny hopsage; the herbs were dominated by cheatgrass and Sandberg bluegrass. Spiny hopsage appeared to be vulnerable to burning and also to damage by off-road vehicular traffic. It appears to have little or no ability to reproduce through seedlings; once the existing plants are killed they are not likely to be replaced, even if seed-producing plants are nearby. The only pure stand of spiny hopsage known to exist on the Hanford Site is on and near study plot 2H. Sagebrush, like spiny hopsage, is killed by burning and by heavy vehicles. Sagebrush is capable of reproducing via seeds, indicating that it is an inherently aggressive species with a capacity to reestablish itself if parent plants are in the vicinity to act as seed sources. Alien, annual plants, especially cheatgrass, were a major contributor to the herbaceous canopy cover in plots 3S, 4S, and 5S. However, native perennial grasses, especially Sandberg bluegrass, were ...

Gene expression profiles deciphering rice phenotypic variation between Nipponbare (Japonica) and 93-11 (Indica) during oxidative stress.

Spontaneous mutation has been discovered and utilized in domestication of narrow-leafed lupin (Lupinus angustifolius L.). As the result of the domestication, lupin has become a dominant grain legume crop in Western Australia. Facing the new challenge of developing herbicide tolerance cultivars, chemical mutagenesis has been used to create new tolerance to herbicide. This paper reports the characterization of two lupin mutants (Tanjil-AZ-33 and Tanjil-AZ-55) that are highly tolerant to metribuzin herbicide. A dose response study over 8 doses revealed that Tanjil-AZ-33 was 6 times more tolerant to metribuzin than the original parental cultivar Tanjil by measure of LD50. This mutant Tanjil-AZ-33 is the most tolerant germplasm in narrow-leafed lupin. Both mutants also maintain the high resistance to the disease anthracnose as cv Tanjil. Seed yield based on small field plots (3.6 m"2) under irrigation was 4.2 t/ha for Tanjil-AZ-33 and 1.9 t/ha for Tanjil when the ...

2008-08-12

Fluxes of H+ and K+ in corn roots

Rice is a very important food staple that feeds more than half the world's population. Two major Asian cultivated rice (Oryza sativa L.) subspecies, japonica and indica, show significant phenotypic variation in their stress responses. However, the molecular mechanisms underlying this phenotypic variation are still largely unknown. A common link among different stresses is that they produce an oxidative burst and result in an increase of reactive oxygen species (ROS). In this study, methyl viologen (MV) as a ROS agent was applied to investigate the rice oxidative stress response. We observed that 93-11 (indica) seedlings exhibited leaf senescence with severe lesions under MV treatment compared to Nipponbare (japonica). Whole-genome microarray experiments were conducted, and 1,062 probe sets were identified with gene expression level polymorphisms between the two rice cultivars in addition to differential expression under MV treatment, which were assigned as Core ...

2010-01-08

Evaluation of the F_1 sterility technique for population suppression of the pink bollworm, Pectinophora gossypiella (Saunders)

We report here on an experimental system that utilizes ion-selective microelectrodes to measure the electrochemical potential gradients for H"+ and K"+ ions within the unstirred layer near the root surface of both tact 4-day-old corn seedlings and corn root segments. Analysis of the steady state H"+ and K"+ electrochemical potential gradients provided a simultaneous measure of the fluxes crossing a localized region of the root surface. Net K"+ influx values obtained by this method were compared with unidirectional K"+ ("8"6Rb"+) influx kinetic data; at any particular K"+ concentration, similar values were obtained by either technique. The ion-specific microelectrode system was then used to investigate the association between net H"+ efflux and net K"+ influx. Although the computed H"+K"+ stoichiometry is dependent upon the choice of diffusion coefficients, the values obtained were extremely variable, and net K"+ influx rarely appeared to be charge-balanced by H"+ ...

1987-01-01

Coordinated responses of phytochelatin synthase and metallothionein genes in black mangrove, Avicennia germinans, exposed to cadmium and copper

Field cage studies were carried out to evaluate the F_1 sterility technique for population suppression of the pink bollworm, Pectinophora gossypiella (Saunders), in cotton. For this purpose, six field cages (1.8 m x 1.8 m x 1.8 m) were placed over cotton seedlings in the field. Five pairs of laboratory reared, untreated adult moths were released in all six cages during the first week of August. In addition, on the same data 100 pairs of adults, following irradiation of the mature pupae at 100 Gy, were released in two cages and 250 such pairs of irradiated adults in two other cages in ratios of 20:1 and 50:1 (irradiated:normal), respectively. The results of per cent larval infestation in the rosette blooms in different field cages indicated that larval infestation in the flowers was significantly lower (4.93%) in cages where the moths were released at the 50:1 ratio than in cages where moths were released at the 20:1 ratio (6.71%). Larval infestation in the flowers ...

1993-09-01

100

Coordinated responses of phytochelatin synthase and metallothionein genes in black mangrove, Avicennia germinans, exposed to cadmium and copper

To evaluate the role of phytochelatins and metallothioneins in heavy metal tolerance of black mangrove Avicennia germinans, 3-month-old seedlings were exposed to cadmium or copper for 30 h, under hydroponic conditions. Degenerate Mt2 and PCS primers were synthesized based on amino acid and nucleotide alignment sequences reported for Mt2 and PCS in other plant species found in GenBank. Total RNA was isolated from A. germinans leaves and two partial fragments of metallothionein and phytochelatin synthase genes were isolated. Gene expression was evaluated with reverse transcripatase-polymerase chain reaction (RT-PCR) amplification technique. Temporal analysis showed that low Cd{sup 2+} and Cu{sup 2+} concentrations caused a slight (but not significant) increase in AvMt2 expression after a 16 h exposure time, while AvPCS expression showed a significant increase under the same conditions but only after 4 h. Results strongly suggest that the rapid increase in AvPCS ...

2007-08-01

1 2 3 4 5 6

101

Water-level variations and their effects on tree growth and mortality and on the biogeochemical system at the phytoremediation demonstration site in Fort Worth, Texas, 1996-2003

To evaluate the role of phytochelatins and metallothioneins in heavy metal tolerance of black mangrove Avicennia germinans, 3-month-old seedlings were exposed to cadmium or copper for 30 h, under hydroponic conditions. Degenerate Mt2 and PCS primers were synthesized based on amino acid and nucleotide alignment sequences reported for Mt2 and PCS in other plant species found in GenBank. Total RNA was isolated from A. germinans leaves and two partial fragments of metallothionein and phytochelatin synthase genes were isolated. Gene expression was evaluated with reverse transcripatase-polymerase chain reaction (RT-PCR) amplification technique. Temporal analysis showed that low Cd"2"+ and Cu"2"+ concentrations caused a slight (but not significant) increase in AvMt2 expression after a 16 h exposure time, while AvPCS expression showed a significant increase under the same conditions but only after 4 h. Results strongly suggest that the rapid increase in AvPCS expression ...

2007-08-01

102

Evolution of improved varieties of sesame through induced mutations

In 1996, a field-scale phytoremediation demonstration project was initiated and managed by the U.S. Air Force at a site in western Fort Worth, Texas, using a plantation of 1-year-old stems harvested from branches of eastern cottonwoods during the dormant season (whips) and a plantation of 1-year-old eastern cottonwood seedlings (calipers). The primary objective of the demonstration project was to determine the effectiveness of eastern cottonwoods at reducing the mass of dissolved trichloroethene transported within an alluvial aquifer. The U.S. Geological Survey conducted a study, in cooperation with the U.S. Air Force, to determine water-level variations and their effects on tree growth and mortality and on the biogeochemical system at the phytoremediation site. As part of the study, water-level and water-quality data were collected throughout the duration of the project. This report presents water-level variations at periodic sampling events; data from August ...

2004-01-01

103