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Blue light regulation of stomata in wheat seedlings. I. Influence of red background illumination and initial conductance level
Author(s) -
Karlsson Per Erik
Publication year - 1986
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1986.tb02409.x
Subject(s) - stomatal conductance , photosynthesis , blue light , conductance , light intensity , biophysics , red light , chemistry , botany , horticulture , biology , optics , physics , condensed matter physics
A red background illumination synergistically increased the sensitivity of the stomatal conductance response to low intensity blue light in wheat seedlings ( Triticum aestivum L. cv. Starke II, Weibull). It also saturated the photosynthesis dependent mechanisms so that they did not respond to the low quantum fluence rates needed to activate the blue light mechanism. Thus dual beam experiments provide a suitable experimental approach to study the blue light mechanism for stomatal regulation in the intact leaf. Time course studies indicated that in short time experiments the enhancement effect of the red background light was primarily a result of the increase in conductance level rather than a direct effect of the red light. This was confirmed with experiments where the stomatal blue light response was enhanced due to partial stomatal opening in CO 2 free air as well as due to circadian rhythm. During long term experiments the response to blue light gradually decreased. It could then, however, be restored by a simultaneous red background light.