Governing equations for plant cell growth

Abstract
Governing equations are important in the evolution of a science from a qualitative or descriptive state to a quantitative state. This review discusses recent progress made toward the goal of establishing governing equations for plant cell growth. Recent extensions of the previously established growth equations are reviewed, and recent pressure probe methods which have been used to determine the magnitude and behavior of biomechanical and biophysical parameters are emphasized. Two recently developed pressure probe methods (in vivo creep and in vivo stress relaxation), which have been used to determine the wall extensibility and the yield threshold of plant cells, are discussed and compared. Also reviewed are pressure probe methods which have been used to measure the volumetric elastic modulus, and transpiration rate from a single plant cell.