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G A Strobel

Publications and source records attributed to G A Strobel.

At least 19 recordsLinked to original sources
PubMed1982

Phytotoxins.

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Alternaria↗
PubMed1980

Inverse relationship of protein concentration and binding activity of alpha-galactoside receptors from sugarcane membranes.

1. The binding activity of purified alpha-galactoside receptor proteins from a number of plant species decreases when the protein concentration is increased from 2 ng/ml to 100 micrograms/ml. 2. The apparent loss of binding activity at high protein concentrations corresonds to the formation of high molecular weight multimers. 3. Raffinose and melibiose cause a ligant-dependent increase in binding activity and a corresponding decrease in the relative abundance of multimers at any give protein concentration. 4. The self-inhibition of binding activity at high protein concentrations arises from a competition between ligant binding by oligomers and self-association of these oligomers into multimeric species which have little or no binding acitivity.

Binding, Competitive↗
PubMed1979

The relationship between membrane ATPase activity in sugarcane and heat-induced resistance to helminthosporoside.

1. Heating of susceptible sugarcane leaves (4 h at 35 degrees C) renders them resistant, for 24 h, to the effects of helminthosporoside. Membrane ATPase activity is reduced by 50% as a result of the heat treatment. When the leaves again become susceptible (after 24 h), membrane. ATPase activity is fully restored. 2. Inhibitors of membrane ATPase activity protect susceptible leaves from the effects of helminthosporoside (KF, EDTA, and octylguanidine). 3. Helminthosporoside activates (30%) membrane ATPase in microsomes from susceptible, but not heat-treated (resistant) leaves. Once heat-treated leaves again become susceptible, helminthosporoside activation of membrane ATPase activity resumes. 4. A plot of the production of helminthosporoside-induced symptoms, and membrane ATPase activity as a function of the reciprocal of the absolute temperature reveals that both have sharp breaks at 32 degrees C. 5. Protoplasts of susceptible cane are rendered insensitivity to the effects of the toxin in a medium deficient in K+ and Mg2+. When these ions are added, cell sensitivity to the toxin is restored. Since K+ uptake in plants is mediated by membrane ATPase, a connection with this enzyme activity can be made to cell sensitivity to the toxin.

Adenosine Triphosphatases↗
PubMed1977

Bacterial phytotoxins.

Representatives of all of the major genera of plant disease-causing bacteria have been shown to produce one or more phytotoxins. Toxicological studies on the bacterial diseases of the major food crops have not been extensive. Bacterial phytotoxins belong to a number of classes of organic substances, including peptide, derivatized amino acid, polysaccharide, and glycopeptide. The mechanism of action of these compounds is largely unknown, as is their origin and importance in the disease syndrome. Nevertheless, some progress has been made in these areas in isolated cases. There is a tremendous potential in the future for studies on the bacterial phytotoxins.

Bacterial Proteins↗
PubMed1975

Deficiency of toxin-binding protein activity in mutants of sugarcane clone H54-775 as it relates to disease resistance.

Three mutants selected from a population of sugarcane clone H54-775 that had been irradiated with 3 kR gamma-radiation all lacked toxin-binding protein activity. This activity previously had been shown to be essential for eye spot disease susceptibility and was demonstrated in the susceptible parent clone H54-775. In one mutant, the biochemical, immunochemical, and electrophoretic mobilities of the toxin-binding protein were all modified.

Carrier Proteins↗
PubMed1974

Evidence for the presence of the toxin-binding protein on the plasma membrane of sugarcane cells.

Helminthosporoside is a host-specific toxin produced by Helminthosporium sacchari, both in culture and in infected sugarcane tissue. The susceptibility of any given clone of sugarcane to disease is invariably associated with the presence of a toxin-binding protein. This report presents evidence for the presence of the toxin-binding protein on the plasma membrane of the plant cell. This evidence includes, among others: (1) The protection of susceptible plant tissues by prior treatment with antiserum to the binding protein, (2) the successful pyridoxylation and reduction of the binding protein in vivo followed by its isolation, (3) the reaction of sugarcane cells and free protoplasts with [(3)H]antiserum prepared against the binding protein, and (4) the agglutination of sugarcane protoplast preparations with antiserum to the binding protein.

Binding Sites↗
PubMed1968

Origin of cyanide in cultures of a psychrophilic basidiomycete.

An unidentified psychrophilic basidiomycete used valine and isoleucine as precursors to hydrocyanic acid (HCN). As probable intermediates in the pathway from valine and isoleucine two cyanogenic glucosides, linamarin and lotaustralin, were demonstrated in fungus cultures. The fungus contained two beta-glucosidases and an oxynitrilase which, acting together, were capable of releasing cyanide from both linamarin and lotaustralin. The two beta-glucosidases were purified and compared as to pH optimum, Michaelis constant, energy of activation, thermal stability, and substrate specificity. The products of methyl ethyl ketone cyanohydrin and acetone cyanohydrin dissociation by the oxynitrilase were demonstrated to be HCN together with methyl ethyl ketone and acetone, respectively. The oxynitrilase attacked aliphatic hydroxynitriles, but showed no activity on aromatic hydroxynitriles.

Amino Acids↗