Cytoplasma- und Kern-Zustandsänderungen bei Schließzellen

Endogenous Diurnal and Nocturnal Activity of Guard Cells as Indicated by Stomatal Aperture and Protoplasmic Streaming

“…the photoactive process evenUially produced enough osmoticum that, combined with tbe endogenous counterpart, the width of the apparatus finally exceeded that found in the dark. It is, of course, tlien quite impossible to use tbe endogenous component found in dark activity in these studies as an addendum in llie summation process to describe the total or current process in light, somewhat confirming tbe remarks niade by Meidner and Mansfield (1965) and later qualified by Stalfelt (1967). Tbe effect of long wave radiation on leaf water balance is very important in most growtb ehamher studies dealing with plant waler relations and is presently hebig studied in further detail by the author.…”

The Physical Properties of Protoplasm

“…In contradiction to the long held assumption of Heilbrunn (76), Weber (77), and others, KUster (78) found a decrease in the vis cosity of Cladophora protoplasm due to centrifugal force. He sug gests that it is not higher speeds which produce abnormal changes but fractional centrifugation.…”

Light‐Induced Stomatal Movements in Wheat Leaves Recorded as Transpiration Experiments with the Corona‐Hygrometer

“…The invalidity of the product law during the extension phase, especially shown by Harms (10), can Ibus be attributed to the fact that the mechanical resistance against cbanges in the shape of the guard cells is presumed to be greatest at tbese phases of the movement. Since these mechanical influences are due to many different factors snch as waler conditions of the cell.s, including colloidal conditions of tbe protoplasm (Weber,30), it is reasonable to assnme tbat Ihe influence of the.se factors will cause divergences from the product law. Only when the mechanical resistance against opetiing movement is Ihe same during a certain period of time of tbe t>pening prtH'e.ss, can tbe reaction be expected to obey Ibe law; cf.…”