Studies in Plant Metabolism. III. Absorption, Translocation and Metabolism of Radioactive 2,4-D in Corn and Wheat Plants.

Abstract

The use of 2,4-dichlorophenoxyacetic acid (2,4-D) as a selective herbicide has become quite extensive. In general, dicotyledonous plants are more sensitive to 2,4-D treatment than are most plants of the monocotyledonous types (7), although very little is known regarding the factors responsible for the difference in sensitivity. Recently, by using an isotopically labeled herbicide, Wood et al. (10) found that bean plants absorbed and translocated 2-iodo13"-3-nitrobenzoic acid (INBA) more readily than barley plants. Later, Mitchell et al. (8) extended their work to oat and corn plants. They suggested that the growth-inhibiting effect of INBA in the bean plant and its failure to produce significant inhibition in barley, oat and corn plants might be due to the differences in the manner in which INBA reacts with the plant constituents in each case.Gallup and Gustafson (3) using 2,4-dichloro-5-iodo'3l-phenoxyacetic acid were also able to demonstrate that the absorption of this growth regulator by the monocotyledonous plants is slower than by the dicotyledonous ones. The translocation to the apical portion of the plant is very rapid in broadleaved plants, but much less rapid in the grasses.Holley, Boyle and Hand (4) using carboxyl-C14-labeled 2,4-D demonstrated the presence of free 2,4-D in bean plant homogenate. Later Holley (5) using the same labeled preparation was able to show the presence of an ether-insoluble, water-soluble compound. Weintraub et al. (9), by using either carboxyl-or methylene-Cl4-labeled 2,4-D, demonstrated that the C14 from the applied 2,4-D in bean plants is incorporated into other substances within a few days. The radioactive carbon becomes distributed among a variety of plant constituents, including acids, sugar, dextrins, starch, pectin, protein and cell wall substances.In a publication from this laboratory (2) it was found that with bean plants the radioactive 2,4-D was readily absorbed and the radioactivity was found in various parts of the bean plant. In a continuation of this study (6) hours. An aliquot of each ground sample was analyzed for C14 by the usual wet combustion procedure.

Detoxication of Phenol in Annual Plant Seedlings

“…A number of studies performed in vivo and in vitro have demonstrated the importance of glutathione conjugation in the detoxication of triazine and chloroacetanilide herbicides (Shimabukuro et al, 1978;Leavitt and Penner, 1979;Breaux and Patanella, 1985). Conjugates with peptides form chlorophenoxyacetic acids (Fang and Butts, 1954;Durmishidze et al, 1982;Chkanikov, 1985), benzoic acid (Mithaishvili et al, 1978), -naphthol and o-nitrophenol , and phenol (Chrikishvili et al, 1977;Ugrekhelidze et al, 1983).…”

UNTERSUCHUNGEN ÜBER AUFNAHME UND TRANSLOKATION VON 14C‐MARKIERTEN HERBIZIDEN IN AGROSTEMMA GITHAGO L. UND TUSSILAGO FARFARA L.

“…et al, 1962). Fur das Uberfuhren des aufgenommenen 2,4-D in eine immobile Form bestehen verschiedene Moglichkeiten: Konjugationsprodukte im Symplasten (Fang & Butts, 1954;Fang, 1958), Adsorption an Zellbestandteilen (Brian & Rideal, 1952;Brian, 1958), Bildung verschiedener Komplexe mit Aminosauren (Holley, 1952;Jaworski & Butts, 1952;Fang & Butts, 1954;Andreae & Good, 1957;Fang, 1958).…”

Translocation and Complex Formation of Picloram and 2,4‐D in Wheat Seedlings

“…It is generally recognized that a number of factors may contribute to the selective action of auxin herbicides on plants. Early investigations pointed to differences in penetration of the herbicide into the plant (Gallup and 10 Gustafson 1952) or in their translocation within the plant (Fang andButts 1954, Weintraub ct al. 1956) as important factors in selectivity.…”

“…The metabolism of herbicides in plant tissues has been reviewed by Swanson (1965) and Robertson and Kirkwood (1970). Estrusion of the herbicide through the roots is another possible protective mechanism reported for several species (Clor 1961, Reid andHurtt 1970) and suggested to be a factor in selectivity by Fites et al (1964).…”