The limits of sodium/calcium interactions in plant growth

2000 ◽  
Vol 27 (7) ◽  
pp. 709 ◽  
Author(s):  
Robert J. Reid ◽  
F. Andrew Smith
Keyword(s):  
High Salinity ◽  
Foliar Application ◽  
Maximum Growth ◽  
Growth Responses ◽  
Wheat Seedlings ◽  
Low Salinity ◽  
High Concentrations ◽  
Main Component ◽  
Dependent Processes ◽  
Root Plasma Membrane

The amelioration of Na toxicity by supplementation of Ca in the growth medium was investigated in wheat with the aims of (1) identifying the Ca-dependent processes that determine the growth responses and (2) defining the limits to Ca effects on these processes. Growth of wheat seedlings was strongly inhibited by 150 mM NaCl but improved as the Ca concentration in the nutrient medium was increased up to 2.34 mM. Further increasing Ca to 10 mM did not increase growth, nor did foliar application of Ca. Even at high concentrations of Ca, the maximum growth was only approximately 50% of the growth at low salinity. We conclude that the main component of improved growth caused by Ca was via its apoplastic effects on the transport of Na and K across the root plasma membrane, rather than by increasing root or shoot Ca concentrations. There was no evidence that high salinity inhibited Ca uptake to the shoot. The limits to improvement of growth by Ca appear to relate to the fact that, although Ca is able to ameliorate the toxicity caused by high intracellular Na, it is not able to overcome the osmotic deficits associated with high salinity.

scholarly journals Evolution of growth by genetic accommodation in Icelandic freshwater stickleback

2013 ◽  
Vol 280 (1772) ◽  
pp. 20132197 ◽  
Author(s):  
Beren W. Robinson
Keyword(s):  
Genetic Variation ◽  
Rapid Growth ◽  
High Salinity ◽  
Individual Growth ◽  
Growth Responses ◽  
Heritable Variation ◽  
Genetic Accommodation ◽  
Low Salinity ◽  
Evolutionary Response ◽  
Plastic Responses

Classical Darwinian adaptation to a change in environment can ensue when selection favours beneficial genetic variation. How plastic trait responses to new conditions affect this process depends on how plasticity reveals to selection the influence of genotype on phenotype. Genetic accommodation theory predicts that evolutionary rate may sharply increase when a new environment induces plastic responses and selects on sufficient genetic variation in those responses to produce an immediate evolutionary response, but natural examples are rare. In Iceland, marine threespine stickleback that have colonized freshwater habitats have evolved more rapid individual growth. Heritable variation in growth is greater for marine full-siblings reared at low versus high salinity, and genetic variation exists in plastic growth responses to low salinity. In fish from recently founded freshwater populations reared at low salinity, the plastic response was strongly correlated with growth. Plasticity and growth were not correlated in full-siblings reared at high salinity nor in marine fish at either salinity. In well-adapted lake populations, rapid growth evolved jointly with stronger plastic responses to low salinity and the persistence of strong plastic responses indicates that growth is not genetically assimilated. Thus, beneficial plastic growth responses to low salinity have both guided and evolved along with rapid growth as stickleback adapted to freshwater.

Growth responses of periphyton and chironomids exposed to biologically treated bleached kraft pulp mill effluent

1997 ◽  
Vol 35 (2-3) ◽  
pp. 339-345 ◽  
Author(s):  
M. G. Dubé ◽  
J. M. Culp
Keyword(s):  
Kraft Pulp ◽  
Pulp Mill ◽  
Pulp Mill Effluent ◽  
Growth Responses ◽  
High Concentration ◽  
Wood Extractives ◽  
Kraft Pulp Mill ◽  
Bleached Kraft Pulp ◽  
Low Levels ◽  
High Concentrations

Experiments were conducted in artificial streams to determine the effects of increasing concentrations of biologically treated bleached kraft pulp mill effluent (BKPME) on periphyton and chironomid growth in the Thompson River, British Columbia. Periphyton growth, as determined by increases in chlorophyll a, was significantly stimulated at all effluent concentrations tested (0.25%, 0.5%, 1.0%, 5.0% and, 10.0%). Chironomid growth (individual weight) was also significantly stimulated at low effluent concentrations (≤1.0%). At higher concentrations (5.0% and 10.0%), chironomid growth was inhibited relative to the 1.0% treatment streams. Increases in growth were attributed to the effects of nutrient and organic enrichment from BKPME. The effluent contained high concentrations of phosphorus and appears to be an important source of carbon for benthic insects grazing on the biofilm. In high concentration effluent streams, chironomid growth decreased despite low levels of typical pulp mill contaminants. This suggests that other compounds in the effluent, such as wood extractives, may be inhibiting chironomid growth. These results support findings of field monitoring studies conducted in the Thompson River where changes in periphyton and chironomid abundance occurred downstream of the bleached kraft pulp mill.

Carbon-Isotope, Diatom, and Pollen Evidence for Late Holocene Salinity Change in a Brackish Marsh in the San Francisco Estuary

2001 ◽  
Vol 55 (1) ◽  
pp. 66-76 ◽  
Author(s):  
Roger Byrne ◽  
B. Lynn Ingram ◽  
Scott Starratt ◽  
Frances Malamud-Roam ◽  
Joshua N. Collins ◽  
...  
Keyword(s):  
San Francisco ◽  
High Salinity ◽  
Carbon Isotopic Composition ◽  
Brackish Marsh ◽  
San Francisco Estuary ◽  
Freshwater Inflow ◽  
Water Diversion ◽  
Freshwater Flow ◽  
Low Salinity ◽  
Carbon Isotopic

AbstractAnalysis of diatoms, pollen, and the carbon-isotopic composition of a sediment core from a brackish marsh in the northern part of the San Francisco Estuary has provided a paleosalinity record that covers the past 3000 yr. Changes in marsh composition and diatom frequencies are assumed to represent variations in freshwater inflow to the estuary. Three periods of relatively high salinity (low freshwater inflow) are indicated, 3000 to 2500 cal yr B.P., 1700 to 730 cal yr B.P., and ca. A.D. 1930 to the present. The most recent period of high salinity is primarily due to upstream storage and water diversion within the Sacramento–San Joaquin watershed, although drought may also have been a factor. The two earlier high-salinity periods are likely the result of reduced precipitation. Low salinity (high freshwater flow) is indicated for the period 750 cal yr B.P. to A.D. 1930.

Spatial and seasonal variability of emergent aquatic insects and nearshore spiders in a subtropical estuary

2019 ◽  
Vol 70 (4) ◽  
pp. 541 ◽  
Author(s):  
Martha J. Zapata ◽  
S. Mažeika P. Sullivan
Keyword(s):  
Aquatic Insects ◽  
High Salinity ◽  
Aquatic Insect ◽  
Freshwater Ecosystems ◽  
Dispersal Ability ◽  
Insect Community ◽  
Insect Communities ◽  
Low Salinity ◽  
Subtropical Estuary ◽  
Adult Aquatic Insects

Variability in the density and distribution of adult aquatic insects is an important factor mediating aquatic-to-terrestrial nutritional subsidies in freshwater ecosystems, yet less is understood about insect-facilitated subsidy dynamics in estuaries. We surveyed emergent (i.e. adult) aquatic insects and nearshore orb-weaving spiders of the families Tetragnathidae and Araneidae in a subtropical estuary of Florida (USA). Emergent insect community composition varied seasonally and spatially; densities were lower at high- than low-salinity sites. At high-salinity sites, emergent insects exhibited lower dispersal ability and a higher prevalence of univoltinism than low- and mid-salinity assemblages. Orb-weaving spider density most strongly tracked emergent insect density rates at low- and mid-salinity sites. Tetragnatha body condition was 96% higher at high-salinity sites than at low-salinity sites. Our findings contribute to our understanding of aquatic insect communities in estuarine ecosystems and indicate that aquatic insects may provide important nutritional subsidies to riparian consumers despite their depressed abundance and diversity compared with freshwater ecosystems.

scholarly journals Differential Growth Responses of Wheat Seedlings to Elevated CO2

2018 ◽  
Vol 10 (3) ◽  
pp. 400-409 ◽  
Author(s):  
Hamid Reza ESHGHIZADEH ◽  
Morteza ZAHEDI ◽  
Samaneh MOHAMMADI
Keyword(s):  
Leaf Area ◽  
Plant Height ◽  
Elevated Co2 ◽  
Co2 Concentration ◽  
Tolerance Index ◽  
Dry Matter Accumulation ◽  
Wheat Cultivars ◽  
Growth Responses ◽  
Differential Growth ◽  
Wheat Seedlings

Intraspecific variations in wheat growth responses to elevated CO2 was evaluated using 20 Iranian bread wheat (Triticum aestivum L.) cultivars. The plants were grown in the modified Hoagland nutrient solution at a greenhouse until 35 days of age using two levels of CO2 (~380 and 700 µmol mol–1). The shoot and root dry weights of the wheat cultivars exhibited average enhancements of 17% and 36%, respectively, under elevated CO2. This increase was associated with higher levels of chlorophyll a (25%), chlorophyll b (21%), carotenoid (30%), leaf area (54%) and plant height (49.9%). The leaf area (r = 0.69**), shoot N content (r = 0.62**), plant height (r = 0.60**) and root volume (r = 0.53*) were found to have important roles in dry matter accumulation of tested wheat cultivars under elevated CO2 concentration. However, responses to elevated CO2 were considerably cultivar-dependent. Based on the stress susceptibility index (SSI) and stress tolerance index (STI), the wheat cultivars exhibiting the best response to elevated CO2 content were ‘Sistan’, ‘Navid’, ‘Shiraz’, ‘Sepahan’ and ‘Bahar’, while the ones with poor responses were ‘Omid’, ‘Marun’, ‘Sorkhtokhm’ and ‘Tajan’. The findings from the present experiment showed significant variation among the Iranian wheat cultivars in terms of their responses to elevated air CO2, providing the opportunity to select the most efficient ones for breeding purposes.

scholarly journals The genomic sequence ofExiguobacterium chiriqhuchastr. N139 reveals a species that thrives in cold waters and extreme environmental conditions

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3162 ◽  
Author(s):  
Ana Gutiérrez-Preciado ◽  
Carlos Vargas-Chávez ◽  
Mariana Reyes-Prieto ◽  
Omar F. Ordoñez ◽  
Diego Santos-García ◽  
...  
Keyword(s):  
Acid Metabolism ◽  
High Salinity ◽  
Genomic Sequence ◽  
Ultraviolet B ◽  
Comparative Genomic ◽  
Ultraviolet B Radiation ◽  
Genomic Analyses ◽  
High Concentrations ◽  
And Coping ◽  
Cold Lake

We report the genome sequence ofExiguobacterium chiriqhuchastr. N139, isolated from a high-altitude Andean lake. Comparative genomic analyses of theExiguobacteriumgenomes available suggest that our strain belongs to the same species as the previously reportedE. pavilionensisstr. RW-2 andExiguobacteriumstr. GIC 31. We describe this species and propose thechiriqhuchaname to group them. ‘Chiri qhucha’ in Quechua means ‘cold lake’, which is a common origin of these three cosmopolitan Exiguobacteria. The 2,952,588-bpE. chiriqhuchastr. N139 genome contains one chromosome and three megaplasmids. The genome analysis of the Andean strain suggests the presence of enzymes that conferE. chiriqhuchastr. N139 the ability to grow under multiple environmental extreme conditions, including high concentrations of different metals, high ultraviolet B radiation, scavenging for phosphorous and coping with high salinity. Moreover, the regulation of its tryptophan biosynthesis suggests that novel pathways remain to be discovered, and that these pathways might be fundamental in the amino acid metabolism of the microbial community from Laguna Negra, Argentina.

scholarly journals Multiwalled carbon nanotubes in alfalfa and wheat: toxicology and uptake

2012 ◽  
Vol 9 (77) ◽  
pp. 3514-3527 ◽  
Author(s):  
Pola Miralles ◽  
Errin Johnson ◽  
Tamara L. Church ◽  
Andrew T. Harris
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Root Elongation ◽  
Wheat Root ◽  
Root Tip ◽  
Multiwalled Carbon ◽  
Wheat Seedlings ◽  
Industrial Grade ◽  
High Concentrations ◽  
Multiwalled Cnts

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.

scholarly journals Influence of the temperature factor on regeneration features of Silene Jailensis N.I. Rubtzov and Crepis Purpurea (Willd.) M. Bieb. and the content of phenolic substances in vitro

2020 ◽  
pp. 87-96
Author(s):  
I. V. Mitrofanova ◽  
N. N. Ivanova ◽  
A. E. Paliy ◽  
I. N. Paliy ◽  
O. V. Mitrofanova
Keyword(s):  
Phenolic Compounds ◽  
Biochemical Study ◽  
Adventitious Shoots ◽  
Maximum Growth ◽  
Rare Plant ◽  
Temperature Influence ◽  
Phenolic Substances ◽  
Morphogenetic Potential ◽  
High Concentrations

The results of temperature influence on the regeneration of microshoots and the level of phenolic compounds in microshoots of two rare plant species under in vitro conditions are presented. It is shown that the maximum growth of the main and the formation of adventitious shoots, leaves occurred at a temperature of 21- 23°C. Reconnaissance experiments on the biochemical study of organs and tissues of the studied species were conducted. It was found that the leaves contain high concentrations of phenolic substances and are characterized by a wide variety of components. It is shown that as the temperature increased, the content of the sum of phenolic substances increased, which negatively affected the morphogenetic potential of the studied species.

Anaerobic Treatment of Industrial Wastewater Containing Organic Solvents

1994 ◽  
Vol 29 (9) ◽  
pp. 321-329 ◽  
Author(s):  
Evangelos Terzis
Keyword(s):  
Anaerobic Digestion ◽  
Organic Solvents ◽  
Industrial Effluent ◽  
Maximum Growth ◽  
Anaerobic Treatment ◽  
Maximum Growth Rate ◽  
Bacterial Cells ◽  
Precise Control ◽  
Water Charges ◽  
High Concentrations

Industrial water usage results in large volumes of liquid wastes rich in organic pollutants. Waste waters from certain industrial chemical operations (e.g. organic synthesis, perfume industry) will sometimes contain organic solvents at relatively high concentrations. The presence of organic solvents is undesirable in the sewerage system and so must be removed from the industrial effluent. Anaerobic treatment of many of these organic solvents is possible, in which the organic material is converted ~90% to volatile substances -carbon dioxide and methane gas- and ~10% to new bacterial cells (solids). Industry will be using less water in the future. Increased water charges will lead to more precise control and integrated processes will reduce wastage. The smaller volumes of more concentrated waste will be ideal for anaerobic digestion. In order to evaluate the optimum conditions for the anaerobic digestion of propan-2-ol (iso-propanol) the kinetic parameters of the Monod rate model, namely, maximum growth rate (µm), yield (Y), half velocity constant (Ks) and endogenous decay coefficient (Kd), were determined at the temperature range 25°-40°C, inclusively. The regulatory role of molecular hydrogen was investigated and discussed, and also its possible use as a monitor feature in the anaerobic digestion.

Review Lecture - Picoplankton

1986 ◽  
Vol 228 (1250) ◽  
pp. 1-30 ◽  
Keyword(s):  
Natural Waters ◽  
Heterotrophic Bacteria ◽  
Marine Ecosystem ◽  
Radiant Energy ◽  
Euphotic Zone ◽  
Nutrient Status ◽  
Maximum Growth ◽  
Accessory Pigment ◽  
High Concentrations ◽  
Dynamic Population

Picoplankton consists of those organisms found in the open waters of seas and lakes which are capable of passing through a filter with 2 μm pores but not through one with 0.2 μm pores. Cells in this size range are well adapted to planktonic life in that they sink extremely slowly and are more efficient than larger forms in taking up nutrients and absorbing radiant energy. Picophytoplankton includes coccoid cyanobacteria and a variety of eukaryotic algal forms. Strains studied in the laboratory have all been found to show maximum growth at relatively low irradiances, the eukaryotic forms being more efficient than the cyanobacteria in utilizing the blue light which predominates at the bottom of the photic zone in clear oceanic waters. Oceanic strains of coccoid cyanobacteria, however, are characterized by high concentrations of phycoerythrin, which appears to function as a nitrogenous reserve as well as an accessory pigment in photosynthesis. The seasonal and spatial distribution of picophytoplankton seems explicable in terms of these physiological characteristics. Numbers of coccoid cyanobacteria have shown a striking correlation with temperature in a number of different situations. Heterotrophic bacteria are also included in the picoplankton, and a review of the information concerning them suggests that they form a highly dynamic population subsisting on dissolved organic matter liberated by living phytoplankton and zooplankton and by decomposition of dead matter. The productivity of this population in the euphotic zone approaches that of the phytoplankton. Both the picophytoplankton and the bacterioplankton are preyed on by phagotrophic flagellates. Both bacteria and flagellates are active in regeneration of mineral nutrients. Regardless of the salinity, temperature or nutrient status of the water, the numbers of heterotrophic bacteria, picophytoplankton and flagellates tend to be around 10 6 , 10 4 and 10 3 organisms per millilitre respectively. It is suggested that these populations form a basic, self-sustaining and self-regulating community in all natural waters. From present information, it seems that little of the energy which passes through this community finds its way into the larger planktonic organisms, but the role of picoplankton in recycling nutrient elements is of great importance in the marine ecosystem.

Sign in / Sign up

Export Citation Format

Share Document