The behavior of osmotic potential in leaves of maize

Abstract

Large diurnal and seasonal changes in osmotic potential were measured in the upper exposed leaves of Zea mays L. Shaded lower leaves showed little change. The diurnal change was largely due to shifts in solute level, and these could be very rapid following a step change in light. Solute regulation appeared to be a fixed response to light and was not dependent on loss of water volume or turgor. This may severely limit the role of solute level in osmotic adaption to dry conditions.