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PHYTOCHROME CONTROLLED NYCTINASTY IN ALBIZZIA JULIBRISSIN. II. POTASSIUM FLUX AS A BASIS FOR LEAFLET MOVEMENT
Author(s) -
Satter Ruth L.,
Marinoff Philip,
Galston Arthur W.
Publication year - 1970
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.1002/j.1537-2197.1970.tb09891.x
Subject(s) - darkness , biophysics , biology , leaflet (botany) , potassium , botany , anatomy , chemistry , organic chemistry
Excised Albizzia leaflet pairs exposed to red (R) light close within 30–90 min after transfer to darkness. Interruption of darkness by far‐red (FR) light at any time after R inhibits closure within ca. 10 min. Similarly, irradiation with R at any time after prior FR promotes closure within ca. 10 min, and the increased rate of closure is independent of the time lapse between the FR and R irradiations. Closure in the dark is inhibited by NaN 3 and DNP (5 X 10 –4 m ), by anaerobic conditions and by externally applied salts of monovalent cations, especially K; it is also temperature sensitive. Pulvinule cells are very high in K. Electron microprobe analysis of cryostated, lyophilized pulvinules reveals that during closure, K is lost from ventral cells and enters dorsal cells. FR before darkness inhibits the former but not the latter process. Thus, K flux appears to control the changes in volume of the pulvinule cells that control leaflet movement. While leaflet closure normally requires a dark period, salts of organic acids such as sodium acetate, propionate, and butyrate cause closure in the light.