Stimulation of fungal spore germination by volatiles from aged seeds

1978 ◽  
Vol 56 (17) ◽  
pp. 2124-2127 ◽  
Author(s):  
G. E. Harman ◽  
B. Nedrow ◽  
G. Nash
Keyword(s):  
Lipid Peroxidation ◽  
Fusarium Solani ◽  
Carbonyl Compounds ◽  
Fungal Spore ◽  
Pythium Ultimum ◽  
Seed Deterioration ◽  
Storage Fungus ◽  
Pea Seeds ◽  
Stimulation Of ◽  
Aged Seeds

Alaska pea seeds were stored asceptically or with inoculum of Aspergillus ruber, a pathogenic storage fungus, under conditions which induce rapid seed deterioration and permit infection of seeds by A. ruber (30 °C and 92% relative humidity). Volatiles from germinating aged seeds stimulated germination of conidiospores of Fusarium solani f. sp. pisi and Alternaria alternata and chlamydospores of F. solani f. sp. pisi, all in soil-induced stasis, much more than volatiles from unaged seeds. Volatiles from A. ruber - infected seeds were more stimulatory than from comparably aged noninfected seeds when planted in sand, but this effect was not seen when the seeds were planted in soil. Oospores of Pythium ultimum were not stimulated to germinate by volatiles from any seeds. Aged and infected seeds produced up to 24 times more carbonyl compounds than unaged seeds, presumably as a consequence of lipid peroxidation.

Stimulation of fungal spore germination and inhibition of sporulation in fungal vegetative thalli by fatty acids and their volatile peroxidation products

1980 ◽  
Vol 58 (14) ◽  
pp. 1541-1547 ◽  
Author(s):  
G. E. Harman ◽  
L. R. Mattick ◽  
G. Nash ◽  
B. L. Nedrow
Keyword(s):  
Fatty Acids ◽  
Palmitic Acid ◽  
Spore Germination ◽  
Fusarium Solani ◽  
Alternaria Alternata ◽  
Fungal Spore ◽  
Stimulation Of

As little as 200 parts per billion of 2,4-hexadienal in aerial solution stimulated germination of Alternaria alternata conidiospores in soil-imposed stasis. This compound, as well as trans-2-hexene-1-ol, and palmitic acid, stimulated germination of Fusarium solani f. sp. pisi conidiospores. Other 5- to 10-carbon aldehydes, ketones, and alcohols, as well as some 16- to 18-carbon aldehydes and fatty acids, stimulated germination of these spores at 10- or 100-fold higher concentrations. Chlamydospores of F. solanif. sp. pisi were stimulated to germinate by heptanal, octanal, nonanal,trans,trans-2,4-nonadienal, decanal, and undecanal at 20 000 or 20 0000 parts per billion in air, but not by any compound at lower concentrations. Compounds similar to those stimulating germination of conidiospores or chlamydospores inhibited sporulation of vegetative A. alternata thalli at concentrations as low as 800 parts per billion.

scholarly journals Differential Inactivation of Seed Exudate Stimulation of Pythium ultimum Sporangium Germination by Enterobacter cloacae Influences Biological Control Efficacy on Different Plant Species

2003 ◽  
Vol 69 (2) ◽  
pp. 1114-1120 ◽  
Author(s):  
Koji Kageyama ◽  
Eric B. Nelson
Keyword(s):  
Biological Control ◽  
Plant Species ◽  
Enterobacter Cloacae ◽  
Pythium Ultimum ◽  
Damping Off ◽  
Control Efficacy ◽  
Stimulatory Activity ◽  
Seed Exudate ◽  
Pea Seeds ◽  
Stimulation Of

ABSTRACT This study was initiated to understand whether differential biological control efficacy of Enterobacter cloacae on various plant species is due to differences in the ability of E. cloacae to inactivate the stimulatory activity of seed exudates to Pythium ultimum sporangium germination. In biological control assays, E. cloacae was effective in controlling Pythium damping-off when placed on the seeds of carrot, cotton, cucumber, lettuce, radish, tomato, and wheat but failed to protect corn and pea from damping-off. Seeds from plants such as corn and pea had high rates of exudation, whereas cotton and cucumber seeds had much lower rates of exudation. Patterns of seed exudation and the release of P. ultimum sporangium germination stimulants varied among the plants tested. Seed exudates of plants such as carrot, corn, lettuce, pea, radish, and wheat were generally more stimulatory to P. ultimum than were the exudates of cotton, cucumber, sunflower, and tomato. However, this was not directly related to the ability of E. cloacae to inactivate the stimulatory activity of the exudate and reduce P. ultimum sporangium germination. In the spermosphere, E. cloacae readily reduced the stimulatory activity of seed exudates from all plant species except corn and pea. Our data have shown that the inability of E. cloacae to protect corn and pea seeds from Pythium damping-off is directly related to its ability to inactivate the stimulatory activity of seed exudates. On all other plants tested, E. cloacae was effective in suppressing damping-off and inactivating the stimulatory activity of seed exudates.

scholarly journals Stimulation of 5-lipoxygenase activity under conditions which promote lipid peroxidation

1989 ◽  
Vol 263 (2) ◽  
pp. 565-572 ◽  
Author(s):  
D Riendeau ◽  
D Denis ◽  
L Y Choo ◽  
D J Nathaniel
Keyword(s):  
Lipid Peroxidation ◽  
High Speed ◽  
Chemical Reduction ◽  
Gel Filtration ◽  
Maximal Activity ◽  
Lipoxygenase Activity ◽  
Supernatant Fraction ◽  
Acid Oxidation ◽  
Thiol Compounds ◽  
Stimulation Of

The characteristics of hydroperoxide activation of 5-lipoxygenase were examined in the high speed supernatant fraction prepared from rat polymorphonuclear leukocytes. Stimulation of 5-lipoxygenase activity by the 5-hydroperoxyeicosatetraenoic acid (5-HPETE) reaction product was strongly dependent on the presence of thiol compounds. Various reducing agents such as mercaptoethanol and glutathione (0.5-2 mM) inhibited the reaction and increased the concentrations of 5-HPETE (1-10 microM) necessary to achieve maximal arachidonic acid oxidation. The requirement for 5-HPETE was not specific and could be replaced by H2O2 (10 microM) but not by the 5-hydroxyeicosatetraenoic acid (5-HETE) analogue. Furthermore, gel filtration chromatography of the soluble extract from leukocytes resolved different fractions which can increase the hydroperoxide dependence or fully replace the stimulation by 5-HPETE. Maximal activity of the 5-HPETE-stimulated reaction required Ca2+ ions (0.2-1 mM) and ATP with the elimination of the HPETE requirement at high ATP concentrations (2-4 mM). In addition, NADPH (1-2 mM), FAD (1 mM), Fe2+ ions (20-100 microM) and chelated Fe3+ (0.1 mM-EDTA/0.1 mM-FeCl3) all markedly increased product formation by 5-lipoxygenase whereas NADH (1 mM) was inhibitory and Fe3+ (20-100 microM) alone had no effect on the reaction. The stimulation by Fe2+ ions and NADPH was also observed under various conditions which increase the hydroperoxide dependence such as pretreatment of the enzyme preparation with glutathione peroxidase or chemical reduction with 0.015% NaBH4. These results provide evidence for an hydroperoxide activation of 5-lipoxygenase which is not product-specific and is modulated by thiol levels and several soluble components of the leukocytes. They also indicate that stimulation of 5-lipoxygenase activity can contribute to increase lipid peroxidation in iron and nucleotide-promoted reactions.

scholarly journals Deep Brain Stimulation of the Pedunculopontine Tegmental Nucleus Renders Neuroprotection through the Suppression of Hippocampal Apoptosis: An Experimental Animal Study

2020 ◽  
Vol 10 (1) ◽  
pp. 25
Author(s):  
Chellappan Praveen Rajneesh ◽  
Tsung-Hsun Hsieh ◽  
Shih-Ching Chen ◽  
Chien-Hung Lai ◽  
Ling-Yu Yang ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Deep Brain Stimulation ◽  
Brain Stimulation ◽  
Interleukin 6 ◽  
Pedunculopontine Tegmental Nucleus ◽  
Experimental Animals ◽  
Tegmental Nucleus ◽  
Hippocampal Apoptosis ◽  
Deep Brain ◽  
Stimulation Of

The core objective of this study was to determine the neuroprotective properties of deep brain stimulation of the pedunculopontine tegmental nucleus on the apoptosis of the hippocampus. The pedunculopontine tegmental nucleus is a prime target for Parkinson′s disease and is a crucial component in a feedback loop connected with the hippocampus. Deep brain stimulation was employed as a potential tool to evaluate the neuroprotective properties of hippocampal apoptosis. Deep brain stimulation was applied to the experimental animals for an hour. Henceforth, the activity of Caspase-3, myelin basic protein, Bcl-2, BAX level, lipid peroxidation, interleukin-6 levels, and brain-derived neurotrophic factor levels were evaluated at hours 1, 3 and 6 and compared with the sham group of animals. Herein, decreased levels of caspases activity and elevated levels of Bcl-2 expressions and inhibited BAX expressions were observed in experimental animals at the aforementioned time intervals. Furthermore, the ratio of Bcl-2/BAX was increased, and interleukin -6, lipid peroxidation levels were not affected by deep brain stimulation in the experimental animals. These affirmative results have explained the neuroprotection rendered by hippocampus apoptosis as a result of deep brain stimulation. Deep brain stimulation is widely used to manage neuro-motor disorders. Nevertheless, this novel study will be a revelation for a better understanding of neuromodulatory management and encourage further research with new dimensions in the field of neuroscience.

Root-rot resistance in common bean

1993 ◽  
Vol 73 (1) ◽  
pp. 365-367 ◽  
Author(s):  
J. C. Tu ◽  
S. J. Park
Keyword(s):  
Phaseolus Vulgaris ◽  
Rhizoctonia Solani ◽  
Common Bean ◽  
Fusarium Oxysporum ◽  
Key Words ◽  
Fusarium Solani ◽  
Root Rot ◽  
Pythium Ultimum ◽  
Growth Room

A bean (Phaseolus vulgaris) line, A - 300, resistant to Rhizoctonia solani and Fusarium oxysporum was introduced into Ontario from Colombia. The results of tests conducted in a root-rot nursery, in a greenhouse and in a growth room showed that this bean line is resistant to Fusarium solani f. sp. phaseoli and Pythium ultimum. Key words: Bean, Phaseolus vulgaris, root rot resistance

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