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AN OSCILLATING SYSTEM REGULATING DEVELOPMENT OF PLANTS
Author(s) -
Gregory Anne,
Klein Attila O.
Publication year - 1978
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.1978.tb07576.x
Subject(s) - phytochrome , phaseolus , raphanus , avena , far red , oscillation (cell signaling) , horticulture , red light , period (music) , biology , botany , zoology , chemistry , physics , biochemistry , acoustics
Phytochrome conversion shifts the developmental pattern of dark‐grown bean ( Phaseolus vulgaris ) seedlings. Red light was found to initiate rapid oscillations in a system that links illumination with subsequent growth. A single 8 s flash of red light increased the average leaf weight measured 24 h later by 8%. When total illumination was kept constant but the interval between two 4 s flashes was varied, the resulting leaf weight increase was not uniform but depended on the length of the interval between flashes and showed a series of deep minima followed by sharp maxima. Weight increase at the maximum was 60% greater than at the minimum. The minimum‐maximum transitions recurred every 45 s for at least 22 min. Four s of far red light interposed between the two red flashes abolished the oscillation. Temperature between 15 and 30°C had no significant influence on the period of the oscillation but the period varied directly with the duration of the initial red flash. A 2 s initial flash resulted in a 35 s period, while 40 s of red light caused a 2 min period. Oat ( Avena sativa ) and radish ( Raphanus sativus ) seedlings were found to possess similar oscillating mechanisms of growth regulation. The lack of pronounced temperature effects as well as our other findings, suggest that this oscillating system may participate in the time measuring as well as growth regulating mechanisms by which phytochrome controls circadian periodicity and development.