THE NATURAL OCCURRENCE OF AN ANTIBIOTIC IN THE MYCORRHIZAL FUNGUS CENOCOCCUM GRANIFORME

1964 ◽  
Vol 10 (3) ◽  
pp. 323-328 ◽  
Author(s):  
George N. Krywolap ◽  
Larry F. Grand ◽  
L. E. Casida Jr.
Keyword(s):  
Populus Tremuloides ◽  
Mycorrhizal Fungus ◽  
Antibiotic Activity ◽  
Natural Occurrence ◽  
Trembling Aspen ◽  
Mycorrhizal Roots ◽  
Cenococcum Graniforme ◽  
Surrounding Soil

Antibiotic activity chromatographically resembling that produced in vitro by Cenococcum graniforme has been demonstrated in extracts from C. graniforme mycorrhizae and from roots and needles of three species of conifers. In trembling aspen (Populus tremuloides Michx.), activity was observed only in mycorrhizal roots and not in leaves. Seedlings of conifers, presumably devoid of C. graniforme mycorrhizae, also contained antibiotic resembling that of C. graniforme. However, the surrounding soil, which contained C. graniforme sclerotia, also exhibited the antibiotic on extraction with acetone but not on extraction with saline.

Phoma etheridgei sp.nov. from black galls and cankers of trembling aspen (Populus tremuloides) and its potential role as a bioprotectant against the aspen decay pathogen Phellinus tremulae

1994 ◽  
Vol 72 (10) ◽  
pp. 1424-1431 ◽  
Author(s):  
Leonard J. Hutchison ◽  
P. Chakravarty ◽  
Lawrence M. Kawchuk ◽  
Yasuyuki Hiratsuka
Keyword(s):  
Populus Tremuloides ◽  
Potential Role ◽  
Molecular Characteristics ◽  
Natural Ecosystem ◽  
Antifungal Compounds ◽  
Trembling Aspen ◽  
Aspen Wood ◽  
Liquid Media ◽  
Antifungal Metabolites

Phoma etheridgei is described and illustrated from isolates obtained from the bark of black galls and cankers of trembling aspen in Alberta. Comparisons are made with Phoma enteroleuca and several other mostly wood-inhabiting Phoma spp. using morphological, physiological, and molecular characteristics. A key is provided for the differentiation of Phoma spp. that could potentially be isolated from Populus wood. Phoma etheridgei produced antifungal compounds that were strongly inhibitory in vitro to the aspen decay pathogen Phellinus tremulae on agar, in liquid media and on aspen wood chips, and may play a role in the natural ecosystem as an antagonist to Phellinus tremulae. Key words: Phoma etheridgei, taxonomy, black gall, antifungal metabolites, biological control, Phellinus tremulae, Populus tremuloides.

AN ANTIBIOTIC PRODUCED BY THE MYCORRHIZAL FUNGUS CENOCOCCUM GRANIFORME

1964 ◽  
Vol 10 (3) ◽  
pp. 365-370 ◽  
Author(s):  
George N. Krywolap ◽  
L. E. Casida Jr.
Keyword(s):  
Absorption Spectra ◽  
Mycorrhizal Fungus ◽  
Ultraviolet Absorption ◽  
Microbial Inhibition ◽  
Cenococcum Graniforme

An antibiotic active against representatives of the bacteria, yeasts, and actinomycetes has been extracted from the mycelium, produced in vitro, of several strains of the mycorrhizal fungus, Cenococcum graniforme. No activity was observed in culture fluids of this organism. The antibiotic differed from that found in Boletus luteus mycelium by its microbial inhibition and ultraviolet absorption spectra.

scholarly journals Ethylene enhances root water transport and aquaporin expression in trembling aspen (Populus tremuloides) exposed to root hypoxia

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xiangfeng Tan ◽  
Mengmeng Liu ◽  
Ning Du ◽  
Janusz J. Zwiazek
Keyword(s):  
Gas Exchange ◽  
Water Transport ◽  
Populus Tremuloides ◽  
Leaf Gas Exchange ◽  
Hydraulic Conductance ◽  
Root Hydraulic Conductance ◽  
Trembling Aspen ◽  
Expression Levels ◽  
Root Hypoxia ◽  
Exogenous Ethylene

Abstract Background Root hypoxia has detrimental effects on physiological processes and growth in most plants. The effects of hypoxia can be partly alleviated by ethylene. However, the tolerance mechanisms contributing to the ethylene-mediated hypoxia tolerance in plants remain poorly understood. Results In this study, we examined the effects of root hypoxia and exogenous ethylene treatments on leaf gas exchange, root hydraulic conductance, and the expression levels of several aquaporins of the plasma membrane intrinsic protein group (PIP) in trembling aspen (Populus tremuloides) seedlings. Ethylene enhanced net photosynthetic rates, transpiration rates, and root hydraulic conductance in hypoxic plants. Of the two subgroups of PIPs (PIP1 and PIP2), the protein abundance of PIP2s and the transcript abundance of PIP2;4 and PIP2;5 were higher in ethylene-treated trembling aspen roots compared with non-treated roots under hypoxia. The increases in the expression levels of these aquaporins could potentially facilitate root water transport. The enhanced root water transport by ethylene was likely responsible for the increase in leaf gas exchange of the hypoxic plants. Conclusions Exogenous ethylene enhanced root water transport and the expression levels of PIP2;4 and PIP2;5 in hypoxic roots of trembling aspen. The results suggest that ethylene facilitates the aquaporin-mediated water transport in plants exposed to root hypoxia.

The bacteria in sapwood, wetwood, and heartwood of trembling aspen (Populus tremuloides)

1973 ◽  
Vol 51 (2) ◽  
pp. 498-500 ◽  
Author(s):  
Donald M. Knutson
Keyword(s):  
Populus Tremuloides ◽  
Trembling Aspen ◽  
Indigenous Bacteria ◽  
Large Populations ◽  
Xylem Tissue

Bacteria (Erwinia, Bacillus) were consistently isolated from all samples of aspen sapwood and heartwood. In wetwood zones (water-soaked xylem tissue) or discolored heartwood, large populations often occur. No organisms unique to wetwood were isolated. Wetwood probably is formed by nonmicrobial means and, once formed, merely supports large populations of indigenous bacteria.

Wounding of aspen roots promotes suckering

2004 ◽  
Vol 82 (3) ◽  
pp. 310-315 ◽  
Author(s):  
Erin C Fraser ◽  
Victor J Lieffers ◽  
Simon M Landhäusser
Keyword(s):  
Populus Tremuloides ◽  
Growth Rates ◽  
Growing Season ◽  
Organic Layer ◽  
Trembling Aspen ◽  
Layer Depth ◽  
Injury Type ◽  
Organic Layers ◽  
Root Injury ◽  
Root Sucker

In early May, 1-m sections of trembling aspen (Populus tremuloides Michx.) roots in a forest cutblock were carefully exposed and examined for damage. Undamaged roots were subjected to one of three wounding treatments (scrape, sever, or uninjured control) and were then reburied to either the full normal organic layer depth or to one third of the normal depth. Following one growing season, the roots were reexposed and assessed for aspen sucker numbers and growth rates. Results indicate that injured roots produced suckers nearly twice as often as uninjured roots. Further, injured roots produced more suckers per root, and these suckers were taller and had greater leaf area. Roots buried under shallow organic layers also generated more suckers, regardless of injury type. The side of injury (distal or proximal) did not affect any of the measured variables. The present study suggests that moderate wounding of aspen roots increases initial sucker numbers and growth rates.Key words: trembling aspen, root sucker, root injury, regeneration.

THE BEHAVIOUR OF FIVE WOOD SPECIES IN COMPRESSION

IAWA Journal ◽  
2002 ◽  
Vol 23 (2) ◽  
pp. 201-211 ◽  
Author(s):  
Simon Ellis ◽  
Paul Steiner
Keyword(s):  
Young’S Modulus ◽  
Populus Tremuloides ◽  
Wood Species ◽  
Young's Modulus ◽  
Douglas Fir ◽  
Thuja Plicata ◽  
Trembling Aspen ◽  
Moisture Contents ◽  
Red Cedar ◽  
Western Red Cedar

Five wood species, Oregon ash (Fraxinus latifolia Benth.), Balau (Shorea spp.), Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), Western red cedar (Thuja plicata Donn ex D. Don), and Trembling aspen (Populus tremuloides Michx.) were loaded in compression longitudinally, radially and tangentially. The wood cubes were conditioned to one of four moisture contents prior to loading. Small cubes were loaded until no void space remained after which samples were released and soaked in water. Stress /strain curves were recorded over the whole range of strain and cube thicknesses were recorded at the end of the compression, after release from the testing apparatus, and after soaking in water. Denser woods resulted in a greater Young’s modulus, higher levels of stress and shorter time to densification than did less dense woods. Higher initial moisture contents apparently increased the plasticity of the wood leading to a lower Young’s modulus and lower levels of stress during compression, greater springback after release of stress and greater recovery after swelling in water. Differences observed in the radial and tangential behaviours were believed to be due to the supporting action of the rays when the wood was compressed in the radial direction in balau and trembling aspen and to the relative difference between the lower density earlywood and higher density latewood regions in ash, Douglas-fir and western red cedar.

scholarly journals Antifungal Activity of Western Australian Soil Actinomycetes against Phytophthora and Pythium Species and a Mycorrhizal Fungus, Laccaria laccata

1983 ◽  
Vol 36 (2) ◽  
pp. 191 ◽  
Author(s):  
D Keast ◽  
C Tonkin
Keyword(s):  
Antifungal Activity ◽  
Phytophthora Cinnamomi ◽  
Mycorrhizal Fungus ◽  
Organic Matter Content ◽  
Phytophthora Species ◽  
Matter Content ◽  
Soil Organic Matter Content ◽  
Soil Actinomycetes ◽  
High Degree

Soil pH, soil moisture content and soil organic matter content did not appear to influence significantly the total numbers of actinomycetes isolated from sample sites in Western Australia. However, seasonal influences exist with summer conditions leading to higher spore isolation. Substantial but non-specific antifungal activity against Phytophthora cinnamomi, P. cryptogea, P. nicotiana, Pythium proli/erum and L. laccata was detected in vitro from many of the 2367 actinomycetes isolated. Antifungal activity mayor may not occur in members of the same actinomycete group, suggesting segregation of antifungal capacity within all groups. A limited number of actinomycete groups was isolated from the rhizosphere of plants and these exhibited similar properties to their counterparts in soil or litter. Actinomycetes isolated from the rhizosphere of Pinus radiata produced a high degree of in vitro antifungal activity against the Phytophthora species but, in general, actinomycetes isolated from root surfaces exhibited antibiosis against all the fungi tested. More actinomycetes showed antifungal activity from soils where P. cinnamomi was causing dieback of jarrah and other understorey species.

Annual differences in quality of leaf litter of aspen (Populus tremuloides) affecting rates of decomposition

1988 ◽  
Vol 66 (10) ◽  
pp. 1940-1947 ◽  
Author(s):  
Barry R. Taylor ◽  
Dennis Parkinson
Keyword(s):  
Water Absorption ◽  
Leaf Litter ◽  
Populus Tremuloides ◽  
Decomposition Rate ◽  
Rocky Mountains ◽  
Absorption Rate ◽  
Trembling Aspen ◽  
Leaching Loss ◽  
The Difference

Freshly fallen leaf litter was collected from a stand of trembling aspen (Populus tremuloides Michx.) in the Rocky Mountains of Alberta each autumn from 1981 through 1984. Leaves from 1981 and 1982 were yellow, waxy, and strong. Leaves from 1983 were pale brown and very brittle, and almost 1% of them suffered symmetrical deformities. Leaves from 1984 were composed of 80% yellow leaves and 20% green leaves, which apparently abscissed before senescence. Green and yellow 1984 leaves were distinctly different with respect to total (3 days) leaching loss, leachate conductivity, and proportions of ash, cellulose, and labile material. Green 1984 leaves contained twice as much nitrogen as yellow ones (13.1 vs. 6.5 mg∙g−1) and significantly more phosphorus (1.6 vs. 1.3 mg∙g−1). Leaves of different years varied widely with respect to leaf mass, water absorption rate, mass and conductivity of leachate, and proportions of cellulose, labiles, lignin, and ash, but there was no consistent ordering among years; leaves of different colouration (especially 1981 and 1983) were often physicochemically similar, while leaves identical in appearance were often chemically different. Small but significant differences in N and P concentrations among years were removed by 2 h leaching. Leaves of 1981 decomposing in laboratory microcosms at 26 °C lost less mass than either 1982 or 1983 leaves after 1 month, but not after 2 months. Ability of the cuticle to resist water absorption was probably responsible for the difference in initial decomposition rate.

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