Genes and Proteins for Solute Transport and Sensing

Abstract

Transport processes are required for nutrient acquisition, translocation in the plant and for compartmentation within the cells. The weed Arabidopsis occurs in many environmentally distinct locations around the world, and a significant proportion of the genome of this small plant encodes membrane proteins, especially transport proteins and putative sensors that cope with these conditions. Many of these proteins are homologous to transporters from other organisms including bacteria, fungi and animals. This chapter provides an overview of the components and mechanisms responsible for solute transport and sensing. Described are the basic principles of transport processes and the transporters of the pump and carrier classes found in Arabidopsis. Transport of the most prominent solutes that are taken up and distributed within the plant such as nitrogenous compounds (ammonium, nitrate, amino acids, peptides) and carbohydrates such as sugars (sucrose, glucose) or sugar alcohols (e.g. mannitol) are discussed in some detail.