Summary
-
1.
Exposure of dark-grown gherkin seedlings to blue light causes temporary changes in the level of phenylalanine deaminase (PADAse). Following a time lag of about 90 min the enzyme level increases; about 180 min after the beginning of irradiation it declines again.
-
2.
The light-induced increase in the level of PADAse is due to de-novo enzyme synthesis, since spraying of the plants with cycloheximide prior to the light treatment results in inhibition of the increase in enzyme level.
-
3.
The increase of the enzyme level is a function of light intensity. One of the initial processes involved is the transport of a promotive factor from the cotyledons to the hypocotyl.
-
4.
The decline in the PADAse level which follows the initial increase is probably caused by enhanced inactivation of the enzyme. It can be stopped with cycloheximide, indicating that the inactivation process depends on de-novo protein synthesis.
-
5.
The amount of previously induced PADAse and the capacity of the system to respond to a subsequent light treatment are inversely related.
-
6.
The light-induced changes in PADAse activity are parallel to those in the activity of cinnamic acid hydroxylase, the enzyme responsible for the subsequent step in the synthesis of hydroxycinnamic acids from L-phenylalanine. This result indicates a close connection between the induction of the two enzymes.
-
7.
A hypothesis in advanced which explains the effects of irradiation with blue light (“high-energy” reaction) on phenol synthesis on the basis of enzyme synthesis and enzyme inactivation.
Similar content being viewed by others
References
Bechet, J., and J. M. Wiame: Indication of a specific regulatory binding protein for ornithine-transcarbamylase in Saccharomyces cerevisiae. Biochem. biophys. Res. Commun. 21, 226–234 (1965).
Butler, W. L., S. B. Hendricks, and H. W. Siegelman: Purification and properties of phytochrome. In: Chemistry and biochemistry of plant pigments (T. W. Goodwin, ed.), p. 197–210. London and New York: Acad. Press 1965.
Downs, R. J., H. W. Siegelman, W. L. Butler, and S. B. Hendricks: Photoreceptive pigments for anthocyanin synthesis in apple skin. Nature (Lond.) 205, 909–910 (1965).
Durst, F., and H. Mohr: Phytochrome-mediated induction of enzyme synthesis in mustard seedlings (Sinapis alba L.). Naturwissenschaften 53, 531–532 (1966).
Engelsma, G.: Photo-induced hydroxylation of cinnamic acid in gherkin hypocotyls. Nature (Lond.) 208, 1117–1119 (1965).
—: The influence of light of different spectral regions on the synthesis of phenolic compounds in gherkin hypocotyls in relation to photomorphogenesis. III. Hydroxylation of cinnamic acid. Acta bot. neerl. 15, 394–405 (1966).
Engelsma, G.: Effect of cycloheximide on the inactivation of phenylalanine deaminase in gherkin seedlings. Naturwissenschaften 54 (in press) (1967).
—, and G. Meijer: The influence of light of different spectral regions on the synthesis of phenolic compounds in gherkin hypocotyls in relation to photomorphogenesis. I. Biosynthesis of phenolic compounds. Acta bot. neerl. 14, 54–72 (1965).
Grill, R., and D. Vince: Anthocyanin formation in turnip seedlings (Brassica rapa L.): Evidence for two light steps in the biosynthetic pathway. Planta (Berl.) 63, 1–12 (1964).
Hartmann, K. M.: A general hypothesis to interpret “high-energy phenomena” of photomorphogenesis on the basis of phytochrome. Photochem. Photobiol. 5, 349–366 (1966).
Koukol, J., and E. E. Conn: The metabolism of aromatic compounds in higher plants. IV. Purification and properties of the phenylalanine deaminase of Hordeum vulgare. J. biol. Chem. 236, 2692–2698 (1961).
Malaviya, B., and M. M. Laloraya: Anthocyanin biosynthesis in Celosia seedlings. I. Locus of anthocyanin formation and effect of seedling age. Arch. Biochem. 114, 56–60 (1966).
Meijer, G.: The influence of light quality on the flowering response of Salvia occidentalis. Acta bot. neerl. 6, 395–406 (1957).
Mohr, H.: Differential gene activation as a mode of action of phytochrome 730. Photochem. Photobiol. 5, 469–483 (1966).
Nair, P. M., and L. P. Vining: Cinnamic acid hydroxylase in spinach. Phytochem. 4, 161–168 (1965).
Neish, A. C.: Biosynthetic pathways of aromatic compounds. Ann. Rev. Plant Physiol. 11, 55–80 (1960).
Nitsch, C., et J. P. Nitsch: Effet de la lumière sur l'induction de la phénylalaninedéaminase dans les tissues de tubercule d'Helianthus tuberosus L. C. R. Acad. Sci. (Paris) 262, 1102–1105 (1966).
Scherf, H., and M. H. Zenk: Induction of anthocyanin and phenylalanine ammonia-lyase formation by a high energy light reaction and its control through the phytochrome system. Z. Pflanzenphysiol. 56, 203–206 (1967).
Troyer, J. R.: Anthocyan formation in excised segments of buckwheat-seedling hypocotyls. Plant Physiol. 39, 907–912 (1964).
Zenk, M. H.: Zur Frage der Biosynthese von Gallussäure. Z. Naturforsch. 19b, 83–84 (1964).
Zucker, M.: Induction of phenylalanine deaminase by light and its relation to chlorogenic acid synthesis in potato tuber tissue. Plant Physiol. 40, 779–784 (1965).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Engelsma, G. Photoinduction of phenylalanine deaminase in gherkin seedlings. Planta 75, 207–219 (1967). https://doi.org/10.1007/BF00386320
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00386320