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The Absence of a Role of Absorption, Translocation, or Metabolism in the Selectivity of Picloram and Clopyralid in Two Plant Species

Published online by Cambridge University Press:  12 June 2017

J. Christopher Hall
Affiliation:
Dep. Environ. Biol., Univ. Guelph, Guelph, Ont., Canada N1G 2W1
William H. Vanden Born
Affiliation:
Dep. Plant Sci., Univ. Alberta, Edmonton, Alta., Canada T6G 2P5

Abstract

Experiments were conducted to determine whether differences in sensitivity of sunflower (Helianthus annuus L.), and rapeseed (Brassica napus L.) to 14C-picloram (4-amino-3,5,6-trichloro-2-pyridinecarboxylic acid) and 14C-clopyralid (3,6-dichloro-2-pyridinecarboxylic acid) can be attributed to differences in absorption, translocation, or metabolism of the herbicides. Within 24 h, more than 97% of the radioactivity from picloram or clopyralid was absorbed by the foliage of both plant species. Acropetal transport of both herbicides was similar in the two plant species, with approximately 60% or more of the recovered radioactivity from picloram and clopyralid treatments moving acropetally out of the treated leaf 144 h after application. Less than 6% of the 14C-label from either herbicide treatment moved basipetally in both species. Therefore, differences in absorption and translocation did not account for intra- or inter-species sensitivity differences to the two herbicides. Significantly more 14C-picloram and 14C-clopyralid was converted to water-soluble metabolites in rapeseed than in sunflower plants. However, in rapeseed plants, the pattern of metabolism of both herbicides was similar, indicating that the difference between the metabolism of picloram and clopyralid did not account for the sensitivity difference within this species. It appears that only one picloram and clopyralid metabolite was formed in both plant species as determined by TLC. The metabolite of picloram or clopyralid was a water-soluble conjugate that yielded the carboxylic acid amide of the respective herbicide upon ammonolysis.

Type
Physiology, Chemistry, and Biochemistry
Copyright
Copyright © 1988 by the Weed Science Society of America 

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References

Literature Cited

1. Chaleff, R. S. 1980. Further characterization of picloram-tolerant mutants of Nicotiana tabacum . Theor. Appl. Genet. 58:9195.Google Scholar
2. Chen, L. G., Switzer, C. M., and Fletcher, R. A. 1972. Nucleic acid and protein changes induced by auxin-like herbicides. Weed Sci. 20:5355.Google Scholar
3. Chkanikov, D. I., Pavlova, N. N., Makeev, A. M., and Nazarova, T. A. 1984. Conjugates of picloram and 2,4-D with mustard oils in plants of the family Cruciferae. Soviet Plant Physiol. 31: 257262.Google Scholar
4. Chkanikov, D. I., Makeev, A. M., Pavlova, N. N., and Nazarova, T. A. 1983. Formation of picloram N-glucoside in plants. Soviet Plant Physiol. 30:7074.Google Scholar
5. Devine, M. D., Bestman, H. D., Hall, C., and Vanden Born, W. H. 1984. Leaf wash techniques for estimation of foliar absorption of herbicides. Weed Sci. 32:418425.Google Scholar
6. Hall, J. C., Bassi, P. K., Spencer, M. S., and Vanden Born, W. H. 1985. An evaluation of the role of ethylene in herbicidal injury induced by picloram or clopyralid in rapeseed and sunflower plants. Plant Physiol. 79:1823.Google Scholar
7. Hallmen, U. 1975. Translocation and complex formation of root applied 2,4-D and picloram in susceptible and tolerant species. Physiol. Plant. 34:266272.Google Scholar
8. Hallmen, U. 1974. Translocation and complex formation of picloram and 2,4-D in rape and sunflower. Physiol. Plant. 32: 7883.Google Scholar
9. Hallmen, U. and Eliasson, L. 1972. Translocation and complex formation of picloram and 2,4-D in wheat seedlings. Physiol. Plant. 27:143149.Google Scholar
10. Kudaikina, I. V., Makeev, A. M., and Chkanikov, D. I. 1981. 1-O-(4-amino-3,5,6-trichloropicolyl)-D-gluco-pyranoside, a product of picloram metabolism in plants. Fiziologiya Rastenii 28:435439.Google Scholar
11. Labarca, C., Nicholls, P. B., and Bandurski, R. S. 1965. A partial characterization of indoleacetylinositols from Zea mays . Biochem. Biophys. Res. Comm. 20:641646.Google Scholar
12. Maroder, H. L. and Prego, I. A. 1976. Characterization de un metabolito de picloram que se forms en vinal (Prosopis rucsifolia Gris.). In: Trabajos y Resumenes, III Congreso Asociacion Latino-americana de Malezas “ALAM” y VIII Reunion Argentina de Malezas y su Control, “ASAM”, Mar del Plata. Vol. 1. Pages 193200.Google Scholar
13. Mitchell, B.J.F. and Stephenson, G. R. 1973. The selective action of picloram in red maple and white ash. Weed Res. 13:169178.Google Scholar
14. Turnbull, G. C. 1981. Selectivity of 3,6-dichloro-picolinic acid vs. 2,4-D in rapeseed and Canada thistle. M.S. Thesis. Univ. Guelph, Guelph. 85 pp.Google Scholar
15. Ueda, M. and Bandurski, R. S. 1969. A quantitative estimation - of alkali-labile indole-3-acetic acid compounds in dormant and germinating maize kernels. Plant Physiol. 44:11751181.Google Scholar
16. Zweig, G. and Sharma, J. 1980. Selected methods of sample preparation. Pages 228229 in Zweig, G. and Sharma, J., eds. Handbook of Chromatography: General Data and Principles. Vol. 2. CRC Press, Boca Raton.Google Scholar