Summary
Phytochrome was found by direct spectrophotometry to be present in whole dry seeds of cucumber. This pigment is spectroscopically different from the pigment found in etiolated plants. It shows the phenomenon of inverse reversion; in darkness, the red-absorbing form (Pr) reverts slowly to the far-red-absorbing form (Pfr). This may explain why 75% of the “dry-seed” phytochrome is in the Pfr form.
After imbibition, total phytochrome in the seeds starts to increase. The newly-formed pigment is all in the Pr form and has properties similar to those of “classical” phytochrome of etiolated plants. The relationship of this newly-formed phytochrome with control of germination is presently not known. The dry-seed phytochrome remains unchanged during imbibition and appears to retain its capacity for inverse reversion. This may explain the requirement for continuous or intermittent far-red irradiation in the suppression of germination of cucumber seeds. A similar form of phytochrome may be responsible for control of germination in other seeds which are similarly affected by far-red radiation.
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References
Boisard, J., C. J. P. Spruit, and P. Rollin: Phytochrome in seeds and an apparent dark reversion of Pr to Pfr. Meded. Landbouwhogesch. Wageningen 68, No 17 (1968).
Lint, P. J. A. L. de, and C. J. P. Spruit: Phytochrome destruction following illumination of mesocotyls of Zea mays L. Meded. Landbouwhogesch. Wageningen 63, No. 14 (1963).
Mancinelli, A. L., and H. A. Borthwick: Photocontrol of germination and phytochrome reaction in dark germinating seeds of Lactuca sativa L. Ann. di Bot. 28, 9–24 (1964).
——, and S. B. Hendricks: Phytochrome action in tomato seed germination. Bot. Gaz. 127, 1–5 (1966).
—, and A. Tolkowsky: Phytochrome and seed germination. V. Changes of phytochrome content during the germination of cucumber seed. Plant Physiol. 43, 489–494 (1968).
—, Z. Yaniv, and P. Smith: Phytochrome and seed germination. I. Temperature dependence and relative Pfr levels in the germination of dark-germinating tomato seeds. Plant Physiol. 42, 333–337 (1967).
Rollin, P., et G. Maignan: Nécessité du Prl pour la germination de Lactuca sativa var. “Reine de Mai”. C. R. Acad. Sci. (Paris) 263, 756–759 (1966).
Spruit, C. J. P.: Abnormal phytochrome spectrum in leaves. Biochim. biophys. Acta (Amst.) 143, 260–262 (1967).
Spruit, C. J. P., J. Boisard, and P. Rollin: Spectrophotometric phytochrome in imbibed seeds of dark germinating plants. Plant Physiol. 43, S-15 (1968).
Tobin, E. M., and W. R. Briggs: Phytochrome in embryos of Pinus palustris. Plant Physiol. 44, 148–150 (1969).
Yaniv, Z., and A. L. Mancinelli: Phytochrome and seed germination. II. Changes of Pfr requirement for germination in tomato seeds. Plant Physiol. 42, 1147–1148 (1967).
——, and P. Smith: Phytochrome and seed germination. III. Action of prolonged far-red irradiation on the germination of tomato and cucumber seeds. Plant Physiol. 42, 1479–1482 (1967).
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Partially supported by National Science Foundation grant GB-7526.
279th Communication.
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Spruit, C.J.P., Mancinelli, A.L. Phytochrome in cucumber seeds. Planta 88, 303–310 (1969). https://doi.org/10.1007/BF00387458
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DOI: https://doi.org/10.1007/BF00387458