16] Water flow in plants and its coupling to other processes: An overview

Abstract

This chapter discusses the vast field of possible couplings between water transport and other processes as they occur, for example, during gas exchange, during water and nutrient uptake into the root, or during the coupled flow of water and assimilates in the phloem. Some basic phenomena of the coupling between water and solute transport at the cell and tissue level and coupling phenomena between water transport and cell wall mechanics are considered as they occur during water stress, osmoregulation, or growth. The chapter also describes the water–solute interactions in roots where they are most obvious. In most cases, results obtained with pressure probe techniques are reported and compared with others. The analysis of water and solute relations of roots indicates a strong coupling between water and solutes that could be, perhaps, described best in terms of an extended osmometer model of the root. The model should take into account the structural complexity of the root and active pumping.