Photochemistry and Photobiology

Volume 35, Issue 2
February 1982
 Pages 217–221


THE EFFECT OF CYTOKININS ON GROWTH and PIGMENT ACCUMULATION OF RADISH SEEDLINGS (RAPHANUS
SATIVUS L.) GROWN IN THE DARK and AT DIFFERENT LIGHT QUANTA FLUENCE RATES*

Authors

·         Claus Buschmann,

1.

·         Hartmut K. Lichtenthaler

1.

·         First published: February 1982Full publication history

·         DOI: 10.1111/j.1751-1097.1982.tb03835.xView/save citation

·         Cited by: 9 articles

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·

·         *Presented at the Annual European Symposium on Light-Mediated Plant Development, April
6–10, 1981, Bischofmais, W. Germany.

†To whom correspondence and reprint requests should be addressed.

Abstract

Abstract— The dependency of cytokinin effects upon irradiance was studied with radish seedlings
(Raphanus sativus L. cv. Saxa Treib). Kinetin (6-furfurylamino-purine) or BAP
(6-benzylamino-purine) were applied via the roots of plants growing either in continuous darkness
or under high (90 Wm^-2) or low intensity white light (10Wm^-2). Apart from the different
development of plants at low and high fluence rates, the following cytokinin effects were found:

(1) Both cytokinins acted in a similar manner on growth characteristics and pigment accumulation at
high and low light conditions, BAP being in many cases more effective than kinetin.

(2) When compared with the control, the cytokinins suppressed hypocotyl and root lengthening in the
dark and light-grown plants. In darkness they led to increased cotyledon areas, whereas in the
light the leaf expansion was suppressed.

(3) In the etiolated and low light grown plants, the anthocyanin content of the hypocotyls was
enhanced due to the action of cytokinins, whereas under high light the anthocyanin accumulation was
decreased.

(4) In the cotyledons of etiolated plants, more phototransformable protochlorophyll(ide) and more
carotenoids were formed when cytokinins were present. In green leaves the carotenoid content was
diminished due to the action of cytokinins, particularly in plants grown in strong light. The
chlorophyll a/b ratio was increased in the cytokinin-treated plants in most cases.

The results suggest a light dependency of the cytokinin effects. It is believed that the response
of a plant towards exogenously applied cytokinins is similar to that with high intensity light.