Historical Perspectives on Plasmodesmata

Abstract

Immediately following publication of Tangl’s (1879) paper describing ‘open communications’ between protoplasts of endosperm cells of Strychnos, Phoenix and Areca (Frontispiece) there was a spate of claims of prior discovery or at least of prior observation. These claims are discussed by Mühldorf (1937) who like Strasburger (1901) gives Tangl the credit for being the first to realise the full implications of his observations. In Tangl’s own words: “the observations made leave only one correct explanation of the matter, that the protoplasmic bodies of the inner cells of the endosperm are united by thin strands passing through the connecting ducts in the walls, which put the cells into connection with each other and so unite them to an entity of higher order”. In the years following 1879 there was an astonishing output of work extending Tangl’s findings to a wide variety of tissues and plants, virtually exhausting the possibilities of the microscopical methods of the times and enunciating most of the possible hypotheses on the origin, development and function of the structures, which Strasburger (1901) named ‘plasmodesmata’.

“We may ask ourselves if plant cells are in communication with each other and what is the nature of that communication. Many observers believe that they have seen in certain spots a complete absence of intervening cell wall and the cell contents able to pass from one cell to another… One must question whether the dark spots observed by Mirbel on the walls are such openings or whether the extreme tenuousness of the cell communications would probably not permit of their observation, even with the highest magnifications. The former hypothesis is the less probable” Bernhardi, 1805.