In the 1950s, chlorine (as the anion chloride) was established to be as an essential element in higher plants. The function of chloride in the opening and closing of stomatal guard cells has been since clarified and a number of ion transporters for chloride have been identified.

Chloride deficiencies in the natural environment must be very rare to nonexistent since even rainfall contains chloride. Even under laboratory conditions, it is very difficult to induce chloride deficiency. Far more commonly, chloride is associated with saline soils, in which the salt content of the soil solution, usually as chlorides, causes drought-like stress.

This page was last modified by Phillip Barak, Univ. of Wisconsin, on 10 Jan 97. All rights reserved.