Joe D. Robbins

In vitro auxin production by Balansia epichloë

Abstract Balansia epichloe , a systemic plant pathogen isolated from Sporobolus poiretii , was shown to produce the plant growth regulators 3-indole acetic acid, 3-indole ethanol, 3-indole acetamide and methyl-3-indole carboxylate when grown on a medium containing tryptophan. When grown on a tryptophan deficient medium 3-substituted indole derivatives were not detected. However, extracts of the medium in lower doses increased and in higher doses inhibited the growth of wheat coleoptiles.

Laboratory production of ergot alkaloids by species of balansia.

Four species of Balansia (clavicipitaceous systemic grass pathogens) isolated from pastures where cattle showed signs of ergot toxicity were grown in culture. Balansia epichloë, one isolate of B. claviceps, B. henningsiana and two isolates of B. strangulans produced conidia in submerged culture during the first stage of a two-stage fermentation procedure. When tranferred to a glucose/sorbitol/inorganic salts medium during the second stage, these four species produced ergot alkaloids in stationary cultures. The transfer of fungi cultured in the first medium to the second medium was necessary for alkaloid biosynthesis. One isolate of B. claviceps did not produce alkaloids. Balansia epichloë produced chanoclavine (I), agroclavine, penniclavine, elymoclavine, ergonovine and ergonovinine. Balansia claviceps produced chanoclavine (I), ergonovine and ergonovinine. This is the first report of isolating ergonovine and ergonovinine, two lysergic acid derivatives, from fungi outside the genus Claviceps. Only chanoclavine (I) was identified from extracts of B. strangulans and B. henningsiana. Chanoclavine (I) and ergonovine were identified from smut grass (Sporobolus poiretii) parasitized by B. epichloë, indicating that this endophyte produces alkaloids both in vivo and in vitro.

Bioavailability in rabbits of formaldehyde from durable‐press textiles

Carbon-14-labeled formaldehyde was used per se, or was used in the synthesis of dimethyloldihydroxyethyleneurea (DMDHEU), which was incorporated into cotton or cotton/polyester blend fabric. Patches of the fabric containing known quantities of radioactive DMDHEU were applied to the backs of New Zealand White rabbits for periods up to 48 h. The rabbits were placed in specially constructed metabolism chambers designed to prevent either inhalation of volatile material emanating from the fabric or interference of any volatile material from the fabric with trapping of expired carbon dioxide. The results of the studies indicate that aqueous formaldehyde covered with a latex barrier is absorbed and retained in the layers of skin in direct contact with the formaldehyde. Approximately 65% of a dose of [14C] formaldehyde was recovered in skin 4 h after application. Skin samples from the backs of rabbits to which durable-press fabric prepared from radiolabeled DMDHEU had been applied were found to have 0.09-2.61% of the total 14C contained in the cloth patches. The levels of radioactivity recovered from the skin varied with degree of occlusion of the cloth, presence or absence of perspiration, type of synthesis used for the preparation of DMDHEU, and whether cotton or cotton/polyester blend fabric was used. Other tissues and organs had only low levels of radioactivity. Injected [14C] formaldehyde was rapidly expired as 14CO2 (28.6% of the dose within 4 h; 37.0% within 48 h). Metabolism and distribution of formaldehyde was found to be dependent on route of administration: i.e., topical application resulted in high skin levels, whereas intravenous injection led to rapid pulmonary and renal excretion and retention of radioactivity in liver, kidney, and blood.

Occurrence and clinical manifestations of ergot and fescue toxicoses

Historically, ergotism in animals has been defined as a disease of livestock consuming the sclerotia of Claviceps sp. infected grasses. The gangrenous form of ergot toxicity most frequently occurs when animals are exposed to Claviceps purpurea on feed grains and pasture grasses. This type of ergotism is a great risk to livestock, especially cattle. The convulsive form of ergotism, a nervous disorder ranging from mild tremors to severe tetany, is observed in cattle grazed on Paspalum grasses infected with Claviceps paspali [24, 45, 49, 50, 57].

Isolation and characterization of three self-inhibitors of germination from aeciospores of Cronartium fusiforme

The germination inhibition activity of a crude aqueous extract from aeciospores of Cronartium fusiforme was tested against seven rust species and three spore types and found to be aeciospore specific but not species specific. Inhibition was assessed by a germination bioassay. Three self-inhibitors were isolated and purified from the aqueous extract. The ED 100 values of the self-inhibitors were 12.0–30.0, 2.3–7.2, and 3.1–11.9 μ g/ml. The activity of the combined self-inhibitors was 0.81–1.25 μ g/ml, indicating a synergistic effect. The self-inhibitors were structurally similar molecules containing only carbon, hydrogen, and oxygen, with no aromatic rings or unusual bonding.