Evidence for the involvement of the soil microbiota in the exclusion of Fusarium from coniferous forest soils

1984 ◽  
Vol 30 (2) ◽  
pp. 142-150 ◽  
Author(s):  
David A. Schisler ◽  
R. G. Linderman
Keyword(s):  
Forest Soil ◽  
Pacific Northwest ◽  
Propylene Oxide ◽  
Forest Soils ◽  
Germ Tube ◽  
Coniferous Forest ◽  
Nutritional Properties ◽  
Soil Microbiota ◽  
High Concentrations ◽  
Stimulation Of

Fusarium was recovered from only 1 of 14 Pacific Northwest coniferous forest soils but from all 7 nursery soils tested. Assays using high concentrations of Fusarium oxysporum macroconidia added to soil determined that forest soils stimulate macroconidial germination [Formula: see text] often followed by germ-tube lysis or the formation of stunted chlamydospores, while nursery soils support little macroconidial germination [Formula: see text]. Treatment of forest soils with aerated steam (minimum of 45 °C for 30 min), radiation, or propylene oxide reduced the amount of germination in forest soils, suggesting that the forest soil microbiota is involved in the stimulation of macroconidial germination. Bacteria isolated from F. oxysporum hyphae placed in forest, field, or nursery soils on nylon screens did not significantly influence germ-tube lysis when combined with macroconidia in a nutrient broth. Chemical, physical, and nutritional properties of forest soils likely affect the capacity of the forest soil microbiota to influence Fusarium macroconidial germination and germ-tube lysis.

Nitrosospira, an important ammonium-oxidizing bacterium in fertilized coniferous forest soil

1985 ◽  
Vol 31 (3) ◽  
pp. 190-197 ◽  
Author(s):  
Pertti J. Martikainen ◽  
Eeva-Liisa Nurmiaho-Lassila
Keyword(s):  
Forest Soil ◽  
Forest Soils ◽  
Exponential Growth ◽  
Doubling Time ◽  
Coniferous Forest ◽  
Growth Yield ◽  
Wood Ash ◽  
Pine Forest ◽  
Treated Soil ◽  
Pure Cultures

Among ammonium-oxidizing autotrophic nitrifiers only Nitrosospira was found in two pine forest soils fertilized with urea or wood ash in southern Finland. A strain isolated from an ash-treated soil was partially characterized. The cells were spirals, mostly of one to three turns; they were either flagellated or not and pili were found. The strain grew best at 20–27 °C at Po2 of 0.21 (shortest doubling time, 29 h). Km(O2) at 27 °C was 0.20 mg/L. Activity per cell during exponential growth ranged from 0.0060 to 0.0085 pmol [Formula: see text] and growth yield from 2.53 × 106 to 3.60 × 106 cells/μmol [Formula: see text]. Pure cultures could not be isolated from urea-fertilized soils. Hyphomicrobium- and seliberia-like bacteria were frequent contaminants of enrichment cultures in these soils. Reasons for the persistence of Nitrosospira in forest soil were discussed.

scholarly journals Influence of Root Distribution on Preferential Flow in Deciduous and Coniferous Forest Soils

Forests ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 986 ◽  
Author(s):  
Ziteng Luo ◽  
Jianzhi Niu ◽  
Baoyuan Xie ◽  
Linus Zhang ◽  
Xiongwen Chen ◽  
...  
Keyword(s):  
Forest Soil ◽  
Forest Soils ◽  
Root Distribution ◽  
Preferential Flow ◽  
Deciduous Forest ◽  
Coniferous Forest ◽  
Soil Layer ◽  
Extreme Rainfall ◽  
Coarse Roots ◽  
Rainfall Events

Root-induced channels are the primary controlling factors for rapid movement of water and solute in forest soils. To explore the effects of root distribution on preferential flow during rainfall events, deciduous (Quercus variabilis BI.) and coniferous forest (Platycladus orientalis (L.) Franco) sites were selected to conduct dual-tracer experiments (Brilliant Blue FCF and Bromide [Br−]). Each plot (1.30 × 1.30 m) was divided into two subplots (0.65 × 1.30 m), and two rainfall simulations (40 mm, large rainfall and 70 mm, extreme rainfall) were conducted in these. Vertical soil profiles (1.00 m × 0.40 m) were excavated, and preferential flow path features were quantified based on digital image analysis. Root (fine and coarse) abundance and Br− concentration were investigated for each soil profile. In deciduous forest, accumulated roots in the upper soil layer induce larger lateral preferential flow as compared to the coniferous forest soil during large rainfall events. Compared with deciduous forest, coniferous forest soil, with higher (horizontal and vertical) spatial variability of preferential flow paths, promotes higher percolation and solute leaching to deeper soil layers during extreme rainfall events. Fine roots, accounting for a larger proportion of total roots (compared to coarse roots), facilitate preferential flow in the 0–40 cm forest soil layer. Overall, our results indicate that the root distribution pattern of different tree species can exert diverse effects on preferential flow in forest soils.

BIOLOGICAL ACTIVITY OF GREY FOREST SOILS OF THE STARODUB AND BRYANSK OPOLIE AGROECOSYSTEMS

2020 ◽  
Keyword(s):  
Biological Activity ◽  
Soil Respiration ◽  
Forest Soil ◽  
Forest Soils ◽  
Humus Horizon ◽  
Natural Ecosystem ◽  
Mineral Fertilization ◽  
Crop Cultivation ◽  
Soil Microbiota ◽  
Grey Forest Soil

The main indicators of biological activity of grey forest soils of the Starodub and Bryansk Opolie in natural ecosystems, regular and intensive agroecosystems, including radioactively contaminated ones, were determined year by year. It is established that the radioactivity of the soils in the natural ecosystem catena of the Starodub Opolie is practically identical. In agroecosystems the radionuclides in soil catenas are redistributed. They are accumulated in the agrohorizons of soil cavities. In the natural ecosystem the total number of invertebrates and the absolute number of earthworms are higher in grey forest soils, having the second humus horizon cavities, than in the grey forest soils of the neighboring low ridge. In both soils of opolie the earthworms predominate among invertebrates, accounting for about 81 % of their total number. Radioactive contamination reduces the number of earthworms less than the intensification of crop cultivation technologies. In the grey forest soil of the regular agroecosystem, this figure is reduced by 56%, and in the grey forest soil with the second humus horizon by 76 %. In intensive agroecosystems the number of earthworms is reduced less, by 39 and 23 %, respectively. The biomass of the microbiota is significantly greater in the grey forest soils with the second humus horizon of the soil cavities than in the grey forest soils of the neighboring low ridge. Radioactive contamination of these soils reduces microbiota biomass less than intensification of crop cultivation technologies. In the grey forest soils of the agroecosystem, this figure is reduced by 50%, and in the grey forest soil with the second humus horizon by 61 %. In the intensive agroecosystem the biomass of microbiota decreases less intensively, by 30 and 46 %, respectively. In the incubation experiment on the grey forest soils of the Bryansk Opolje it is marked that soil enrichment with organic matter activates the soil microbiota more than 2 times. To a lesser extent, soil respiration increases with NPK application. This figure rises more than 5 times with the combined use of straw and NPK. In the field experiment, the cultivation of winter wheat in the crop rotation after annual grasses and mineral fertilization at the rate of NeoPeoKm+Neo activated the soil microbiota by 75-76 %. The biological cultivation technology on the background of the aftereffect of dung, straw and green manure without mineral fertilization causes a decrease in soil respiration and cellulolytic activity, as compared with the intensive technology.

Dynamic and seasonal fluctuations of microarthropod complex in coniferous forest soil

Ekologija ◽  
2008 ◽  
Vol 54 (4) ◽  
pp. 201-215 ◽  
Author(s):  
Irena Eitminavičiūtė ◽  
Audronė Matusevičiūtė ◽  
Algirdas Augustaitis
Keyword(s):  
Forest Soil ◽  
Coniferous Forest ◽  
Seasonal Fluctuations

Nitrification in coniferous forest soils

1990 ◽  
Vol 128 (1) ◽  
pp. 31-44 ◽  
Author(s):  
K. Killham
Keyword(s):  
Forest Soils ◽  
Coniferous Forest

scholarly journals The regulation of glyceride synthesis in isolated white-fat cells. The effects of palmitate and lipolytic agents

1972 ◽  
Vol 128 (5) ◽  
pp. 1057-1067 ◽  
Author(s):  
E. D Saggerson
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Free Fatty Acids ◽  
Fatty Acid Synthesis ◽  
Acid Synthesis ◽  
Fat Cells ◽  
Glyceride Synthesis ◽  
Glucose Incorporation ◽  
High Concentrations ◽  
Stimulation Of

1. 0.5mm-Palmitate stimulated incorporation of [U-14C]glucose into glyceride glycerol and fatty acids in normal fat cells in a manner dependent upon the glucose concentration. 2. In the presence of insulin the incorporation of 5mm-glucose into glyceride fatty acids was increased by concentrations of palmitate, adrenaline and 6-N-2′-O-dibutyryladenosine 3′:5′-cyclic monophosphate up to 0.5mm, 0.5μm and 0.5mm respectively. Higher concentrations of these agents produced progressive decreases in the rate of glucose incorporation into fatty acids. 3. The effects of palmitate and lipolytic agents upon the measured parameters of glucose utilization were similar, suggesting that the effects of lipolytic agents are mediated through increased concentrations of free fatty acids. 4. In fat cells from 24h-starved rats, maximal stimulation of glucose incorporation into fatty acids was achieved with 0.25mm-palmitate. Higher concentrations of palmitate were inhibitory. In fat cells from 72h-starved rats, palmitate only stimulated glucose incorporation into fatty acids at high concentrations of palmitate (1mm and above). 5. The ability of fat cells to incorporate glucose into glyceride glycerol in the presence of palmitate decreased with increasing periods of starvation. 6. It is suggested that low concentrations of free fatty acids stimulate fatty acid synthesis from glucose by increasing the utilization of ATP and cytoplasmic NADH for esterification of these free fatty acids. When esterification of free fatty acids does not keep pace with their provision, inhibition of fatty acid synthesis occurs. Provision of free fatty acids far in excess of the esterification capacity of the cells leads to uncoupling of oxidative phosphorylation and a secondary stimulation of fatty acid synthesis from glucose.

scholarly journals Regulation of interleukin 6 receptor expression in human monocytes and monocyte-derived macrophages. Comparison with the expression in human hepatocytes.

1989 ◽  
Vol 170 (5) ◽  
pp. 1537-1549 ◽  
Author(s):  
J Bauer ◽  
T M Bauer ◽  
T Kalb ◽  
T Taga ◽  
G Lengyel ◽  
...  
Keyword(s):  
Plasma Cells ◽  
Human Peripheral Blood ◽  
Receptor Expression ◽  
Mrna Levels ◽  
Blood Monocytes ◽  
Inflammatory Conditions ◽  
High Concentrations ◽  
Human Primary Hepatocytes ◽  
Stimulation Of

IL-6 is a cytokine with pleiotropic biological functions, including induction of the hepatic acute phase response and differentiation of activated B cells into Ig-secreting plasma cells. We found that human peripheral blood monocytes express the IL-6-R, which is undetectable on the large majority of lymphocytes of healthy individuals. Stimulation of monocytes by endotoxin or IL-1 causes a rapid downregulation of IL-6-R mRNA levels and a concomitant enhancement of IL-6 mRNA expression. IL-6 itself was found to suppress the IL-6-R at high concentrations. A gradual decrease of IL-6-R mRNA levels was observed along in vitro maturation of monocytes into macrophages. We show that downregulation of IL-6-R mRNA levels by IL-1 and IL-6 is monocyte specific, since IL-6-R expression is stimulated by both IL-1 and IL-6 in cultured human primary hepatocytes. Our data indicate that under noninflammatory conditions, monocytes may play a role in binding of trace amounts of circulating IL-6. Repression of monocytic IL-6-R and stimulation of hepatocytic IL-6-R synthesis may represent a shift of the IL-6 tissue targets under inflammatory conditions.

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