Browsing by Author "Jones, Donald W."

Now showing 1 - 2 of 2
  • Thumbnail Image
    Absorption, translocation, and fate of the herbicide, 2-(3,4- dichlorophenyl)-4-methyl-1,2,4-oxadiazolidine-3,5-dione, in cotton
    Jones, Donald W. (Virginia Tech, 1971-08-05)
    Absorption, translocation, and metabolism of the ¹⁴C-labeled herbicide 2-(3,4-dichlorophenyl)-4-methyl-I,2,4-oxadiazolidine-3,5-dione (VCS-438) in cotton (Gossypium hirsutum L. 'Acala 4-42-77') were studied using autoradiography, thin-layer chromatography, and counting. Foliar penetration and acropetal distribution of 14C occurred within 3 hr and increased with time. No basipetal translocation of ¹⁴C out of treated leaves was detected after treatment. Radioactivity first occurred in the leaf veins, then more generally in interveinal tissues distally from the point of application. Absorption into roots of 30-day-old plants via nutrient solution was rapid; translocation into stem and leaves occurred 12 to 24 hr after treatment. Radioactivity was translocated more rapidly in 40-day-old plants. ¹⁴C in leaves of root-treated plants was first located in the veins, then distributed throughout with accumulation of ¹⁴C in lysigenous glands and leaf margins. Little ¹⁴C moved into young growing points; most accumulated in older leaves. Heterocyclic ring-labeled and phenyl ring-labeled VCS-438- ¹⁴C had similar distribution patterns of ¹⁴C, characteristic of compounds
  • Thumbnail Image
    Some effects of dimethyl sulfoxide on absorption, translocation, and membrane permeability in plants
    Jones, Donald W. (Virginia Polytechnic Institute and State University, 1970)
    The influence of DMSO (dimethyl sulfoxide) on foliar absorption and translocation of herbicides and plant membrane permeability was investigated. Primary leaves of bean (Phaseolus vulgaris L., var. Black Valentine) were treated with ¹⁴C-labeled DMSO, 3,6-dicholoro-o-anisic acid (dicamba), 1,1′-dimethyl-4,4′-bipyridinium salt (paraquat) and 2-choloro-4(ethylamino)-6-(isopropylamino)-s-triazine (atrazine). DMSO at concentrations of 25% or more caused by varying degrees of acute toxicity. However, ¹⁴C was generally distributed throughout the plant 5 days after application of DMSO-¹⁴C, as determined by autoradiography and counting. DMSO, 30%, was not as effective as 0.25% Tween 80 (non-ionic surfactant containing polyoxyethylene sorbitan monooleate) in enhancing the absorption and translocation of dicamba, a phloem-mobile herbicide. Tween 80 was more effective than DMSO in enhancing the foliar uptake of atrazine and distributing it within the treated leaves. The contact toxicity and apoplastic movement of paraquat was increased with DMSO. Spectrophotometric studies revealed the absorption spectrum of paraquat was shifted by addition of DMSO. Root uptake of KH₂³²PO₄ by corn (Zea mays L., var. VPI 646) was inhibited by 3% or higher DMSO. Treatments of DMSO reduced oxygen uptake in corn roots. DMSO failed to increase diffusion of labeled solutes through isolated plant cuticular membranes. In Beta vulgaris L. (beet) permeability studies, DMSO increased efflux of betanin from root cells. Combining atrazine with DMSO resulted in a greater increase in membrane permeability. Membrane permeability of corn mitochondria as determined by characteristic swelling and shrinkage was unaffected by DMSO.