Skip to main content Accessibility help

Ultrastructural Changes of Tobacco Chloroplasts Induced by Pyriclor

  • J. Geronimo (a1) and J. W. Herr (a1)


Treatment of tobacco (Nicotiana tabacum L., var. NC-402) with 2,3,5-trichloro-4-pyridinol (pyriclor) leads to progressive disruption of chloroplast ultrastructure. Initial changes include the inception of a spherical form, swelling of the fret system, and commencement of loss of starch. More advanced changes include the complete disappearance of starch, further swelling and disorganization of the fret membrane system, followed by swelling and disruption of the membranes of the granal discs and rupture of the chloroplast envelope. The changes induced by pyriclor on chloroplast ultrastructure in tobacco are analagous to those caused by 2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine (atrazine) on kidney bean (Phaseolus vulgaris L.) and barnyardgrass (Echinochloa crusgalli L. Beauv.). The shape and size of mitochondria were not altered by treatment with the chemical; however, there appeared to be a significant increase in the number of mitochondria present when alterations in chloroplast structure could be seen. The appearance of visual symptoms of phytotoxicity (chlorosis) correlated with the onset of disruptive changes in chloroplast ultrastructure.



Hide All
1. Ashton, F. M., Gifford, E. M. Jr., and Bisalputra, T. 1963. Structural changes in Phaseolus vulgaris induced by atrazine, II. Effects of fine structure of chloroplasts. Bot. Gaz. 124:336343.
2. Gantt, E. and Conti, S. F. 1966. Granules associated with the chloroplast lamellae of Porphyridum cryentum . J. Cell Biol. 29:423434.
3. Good, N. E. 1961. Inhibitors of the Hill reaction. Plant Physiol. 36:788803.
4. Gunning, B. E. S. 1965. The fine structure of chloroplast following aldehyde osmium tetraoxide fixation. J. Cell Biol. 24:7993.
5. Hill, E. R., Putala, E. C., and Vengris, J. 1968. Atrazineinduced ultrastructural changes of barnyardgrass chloroplasts. Weed Sci. 16:377380.
6. Klein, S. and Newman, J. 1966. The greening of etoliated bean leaves and the development of chloroplast fine structure in absence of photosynthesis. Plant Cell Physiol. 7:115124.
7. Lehninger, A. L. 1959. Respiratory-energy transformation. Rev. Modern Physics 31:136146.
8. Luft, J. H. 1961. Improvements in epoxy resin embedding methods. J. Biophys. and Biochem. Cytol. 9:409414.
9. Meikle, R. W. 1969. Inhibition of photosynthesis by pyriclor. Weed Sci. (In press).
10. Novikoff, A. B. and Essner, E. 1962. Pathological changes in cytoplasmic organelles. Fed. Proc. 21:11301142.
11. Reynolds, E. S. 1963. The use of lead citrate at high pH as an electron-opaque stain in electron microscopy. J. Cell Biol. 17:208213.
12. Saloman, T. G. 1966. Action of 3-amino-s-triazole in the ultrastructure of Indian corn chloroplasts. Compt. Rend. Ser. D 262:25102513.
13. Van Overbeek, J. 1964. Survey of mechanisms of herbicide action, p. 387399. In Audus, L. J. (ed). The physiology and biochemistry of herbicides. Academic Press, Inc., New York.

Ultrastructural Changes of Tobacco Chloroplasts Induced by Pyriclor

  • J. Geronimo (a1) and J. W. Herr (a1)


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed