Stomatal behaviour in buffer solutions
by Williams W. T., Shipton M. E. (1950)
in Physiologia Plantarum 3(4): 479-486 –
Stomata open when epidermal strips are immersed in neutral unbuffered salt solutions. Unless due account is taken of such “salt effects” in interpreting results, similar experiments. using buffer solutions provide no reliable evidence of the response of stomata to changes in pH.
Such movements are also light-sensitive, and this factor must be controlled. In Pelargonium the movements are not accompanied by evident starch changes; if these occur they are too small to be demonstrated by simple inspection.
In Na acetate solution, however, Pelargonium shows a starch change of hitherto unrecorded type: the rapid complete disappearance of starch from individual guard-cells.