Summary
In an ultrastructural and cytochemical study of tentoxin-treatedSorghum bicolor (L.) Moench, both bundle sheath and mesophyll plastids were severely affected, Plastids from chlorotic leaf areas lacked most internal membranes yet had plastid ribosomes and large fibrillar areas of plastid DNA. In “recovered areas” (mottled yellow and green), cells were found that had plastids of near-normal ultrastructure as well as the severely affected plastid-types found in chlorotic leaf areas. Polyphenol oxidase (PPO) cytochemistry of these mottled leaf areas indicated that all “recovered” mesophyll plastids had PPO whereas all the abnormal mesophyll plastids showed no activity. Because bundle sheath plastids ofSorghum have no PPO activity at any developmental stage, yet are affected by tentoxin, PPO cannot be uniquely affected by this toxin. We suggest that tentoxin may affect the transport of cytosolic proteins into the plastid.
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References
Arntzen, C. J., 1972: Inhibition of photophosphorylation by tentoxin, a cyclic tetrapeptide. Biochim. biophys. Acta283, 539–542.
Bradbeer, J. W., Börner, T., 1978: Activities of glyceraldehydephosphate dehydrogenase (NADP+) and phosphoribulokinase in two barley mutants deficient in plastid ribosomes. In: Chloroplast Development (Akoyunoglou, G., Argyroudi-Akoyunoglou, J. H., eds.), pp. 727–732. Amsterdam: Elsevier/N. Holland.
Czaninski, Y., Catesson, A. M., 1974: Polyphenoloxidases (plants). In: Electron Microscopy of Enzymes (Hayat, M. A., ed.), Vol. 2, pp. 66–78. New York: Van Nostrand Reinhold.
Downton, W. J. S., Pyliotis, N. A., 1970: Loss of photosystem II during ontogeny ofSorghum bundle sheath chloroplasts. Canad. J. Bot.49, 179–180.
Duke, S. O., Paul, R. N., Wickliff, J. N., 1980: Tentoxin effects on ultrastructure and greening of ivyleaf morningglory (Ipomoea hederacea var.hederacea) cotyledons. Physiol. Plant.49, 27–36.
Durbin, R. D., Uchytil, T. F., 1977: A survey of plant insensitivity to tentoxin. Phytopathology67, 602–603.
Mayer, A. M., Harel, E., 1979: Polyphenol oxidases in plants. Phytochemistry18, 193–215.
Mueller, W. C., Greenwood, A. D., 1978: The ultrastructure of phenol-storing cells fixed with caffeine. J. exp. Bot.29, 757–764.
Postek, M. T., Tucker, S. C., 1976: A new short chemical dehydration method for light microscopy preparations of plant material. Canad. J. Bot.54, 872–875.
Steele, J. A., Uchytil, T. F., Durbin, R. D., Bhatnagar, P., Rich, D. H., 1976: Chloroplast coupling factor 1: A species-specific receptor for tentoxin. Proc. Natl. Acad. Sci. U.S.A.73, 2245–2248.
Templeton, G. E., 1972:Alternaria toxin related to pathogenesis in plants. In: Algal and Fungal Toxins (Ajl, S. J., Nadis, S., Ciegler, A., eds.), pp. 169–192. New York: Academic Press.
Vaughn, K. C.,Duke, S. O., 1981a: Tentoxin-induced loss of plastidic polyphenol oxidase. Physiol. Plant., in press.
- 1981b: Tissue localization of polyphenol oxidase inSorghum. Protoplasma, in press.
—,Downs, B. D., Wilson, K. G., 1980: Ultrastructural and cytochemical studies of “air blisters” inPilea cadierei Gagnep. and Guillaumin. Ann. Bot.46, 221–224.
-Miller, P. D.,Wilson, K. G., 1981: Ultrastructural localization of polyphenol oxidase inAegopodium podograria. Cytobios, in press.
Wellburn, F. A. M., Wellburn, A. R., 1979: Conjoined mitochondria and plastids in the barley mutantalbostrians. Planta147, 178–179.
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Vaughn, K.C., Duke, S.O. Tentoxin effects onSorghum: The role of polyphenol oxidase. Protoplasma 110, 48–53 (1982). https://doi.org/10.1007/BF01314681
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DOI: https://doi.org/10.1007/BF01314681