ABSTRACT
We tested the activity of 11 main compounds identified from Pinus plants on the growth of Dictyostelium discoideum NC4. Four concentrations (1, 0.1, 0.01, 0.001 microg/microl) of each compound were tested using a disk volatilization technique following germination of D. discoideum NC4 spores. Photographs of D. discoideum NC4 fruiting bodies were taken 2 days after treatment. Fenchone (at 0.1, 0.01, and 0.001 microg/microl) and camphene (at 0.01 microg/microl) stimulated growth of D. discoideum NC4. (1S)-(-)-verbenone, (1S)-(-)-alpha-pinene, (+)-beta-pinene, myrcene, (-)-menthone, (-)-bornyl acetate, (S)-(+)-carvone, (-)-camphene, and (R)-(+)-limonene inhibit its growth. All of the compounds at 1 microg/microl had a strong inhibitory effect on cell growth of D. discoideum NC4. Microscopic observation of the fruiting bodies matched the results of growth rate analysis. Most of the inhibitory effects were represented by changes in the shapes of the fruiting bodies. These changes include short sorophores, smaller sized sori, and sori without spores. Our results suggest that inhibition of growth is the most common effect of monoterpenoids on D. discoideum NC4. Nevertheless, some of them, like fenchone and camphene, seem to enhance its growth.
Subject(s)
Dictyostelium/drug effects , Germination/drug effects , Monoterpenes/pharmacology , Pinus/chemistry , Animals , Culture Media, Conditioned , Dictyostelium/growth & development , Dictyostelium/physiology , Fruit/growth & development , Fruit/physiology , Microscopy, Electron , Monoterpenes/chemistry , Monoterpenes/classification , Temperature , Time Factors , VolatilizationABSTRACT
The effects of an aqueous extract of Artemisia princeps var. orientalis and two phenolic compounds on mycorrhizal colonization and plant growth have been investigated. Greenhouse studies showed that the inhibitory effect of the extract on mycorrhizal colonization and plant growth increased in proportion to the concentration of the extract. When the mycorrhizal test plants were treated with an increasing concentration of phenolic compounds, the mycorrhizal colonization in roots of the test plant and the plant growth were decreased. There were strong indications that mycorrhizal fungi mitigated the inhibitory influence of shoot extract of A. princeps var. orientalis and phenolic compounds.
Subject(s)
Artemisia/chemistry , Phenols/pharmacology , Plant Roots/microbiology , Fungi/growth & development , Plant Development , Plant Extracts/pharmacologyABSTRACT
An in vitro study was performed to determine the potential application of tissue culture in determining allelopathic potentialof Artemisia princeps var.Orientalis (wormwood). Aqueous extracts and volatile substances ofA. princeps var.Orientalis were tested to determine their effects on callus induction and growth of several tested species. Extracts of 5%A. princeps var.Orientalis caused some reduction in concentration, induction, and growth of callus, although they looked normal, whereas the expiants of most receptor plants did not develop callus at higher concentration. Lettuce andEclipta prostrata were the most sensitive species, andA. princeps var.Orientalis was affected by its own extracts. The growth of calluses in MS 121 medium treated with essential oil ofA. princeps var.Orientalis was inhibited, and the degree of inhibition was proportional to the concentration of the essential oil.
ABSTRACT
The allelopathic effects of wormwood plants (Artemisia princeps var.orientalis) and their possible phytotoxicity on receptor species were investigated. The aqueous extracts of mature leaf, stem, and root of wormwood plants caused significant inhibition in germination and decreased seedling elongation of receptor plants, whereas germination of some species was not inhibited by extracts of stems and roots. Dry weight growth was slightly increased at lower concentrations of the extract, whereas it was proportionally inhibited at higher concentrations. The calorie value of the organic matter in receptor plants measured by bomb calorimeter was reduced proportionally to the extract concentration. However, results with extracts of juvenile leaf did not correlate with inhibition or promotion of elongation and dry weight.
ABSTRACT
Field and laboratory studies were conducted to examine the differential phytotoxicity of residues ofArtemisia princeps var.orientalis (wormwood) using various plants as test species. Seedling elongation and dry weights of receptor plants were inversely proportional to the concentration and incubation time of dry leaves ofA. princeps var.orientalis in vermiculite. In seedling growth tests with abandoned field soils (control) and soil underneath wormwood plants (test), the elongation, dry weight, and caloric content of seedlings grown in the soil from under wormwood plants were severely inhibited, thereby suggesting that certain growth inhibitors were released from wormwood and the inhibitor remained in the soil.
