Observational and Experimental Studies of Sensitive Plants

The migration of potassium in the petiole of Mimosa pudica

Abstract

By the Macallum's modified method and Mallory's staining, the migration of potassium in the Mimosa petiole is observable.
Before receiving the stimulus the potassium salts appeared in lacunal parenchyma, phloem parenchyma, xylem parenchyma and protoxylem respectively. On the contrary, after receiving the stimulus the potassium salts appeared in the intercellular spaces and/or sieve tubes. Fig. 1 is the schema which is summarized from the data of the cytochemical experiment concerning potassium migration.
In the fixed material, there are still notable differences between the two. In the tissue-cells of xylem parenchyma and protoxylem parenchyma before stimulus is given, the protoplast is observed to be in colloidal mass. After receiving the stimulus the contents of the tissue-cells have disappeared.