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PHOTOINDUCTION OF PHARBITIS FLOWERING: RELATIONSHIP TO RNA SYNTHESIS AND OTHER METABOLIC EVENTS
Author(s) -
Gressel J.,
Zilberstein A.,
Strausbauch L.,
Arzee T.
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.tb07594.x
Subject(s) - pharbitis nil , uridine , rna , biology , stimulus (psychology) , botany , biophysics , biochemistry , gene , psychology , psychotherapist
We have previously shown that a wave of enhanced uridine incorporation into RNA occurs in the more vegetative parts of the plumule at the end of the single dark period that evokes flowering in Pharbitis nil . We demonstrate here that a light break that suppresses flowering suppresses this wave as well. It does not shift the kinetics of the wave of uridine incorporation to a different time. The enhanced incorporation is into all RNA fractions. It had been concluded from excision experiments that the floral stimulus reaches the apex much after photoinduction. There is a metabolic shock caused by such excision of the cotyledons or surgical removal of the plumule that can suppress flowering if it is performed near the end of the inductive dark period. The terminal bud is more affected by this shock than lateral buds. Excision of the cotyledons enhances the rate of incorporation of exogenous uridine into the plumule. We propose that the “floral stimulus” stimulating incorporation into RNA reaches the plumule immediately after the end of the critical dark period.