Water relations and leaf growth

Cell expansion may be described in physical terms by a model in which growth and turgor are linearly related above a threshold value for turgor. Tissue extensibility, an indication of the capacity of cell walls to loosen, is the gradient of this line.The growth of leaves and leaf cell turgor have been directly correlated, but much of the information on the physical characteristics of growth has been obtained from simpler tissue types. For leaves of bean, variation in cell wall extensibility (WEX) may often be the factor controlling growth, maturation, and the response to a decreased water supply (Van Volkenburgh and Cleland, 1980; Davies and Van Volkenburgh, 1983).Diurnal patterns of leaf growth in woody plants cannot always be explained in terms of daily fluctuations in turgor and for birch leaves WEX and growth are correlated