Function and regulation of plant aquaporins
Aquaporins (AQPs) are channels facilitating the movement of water and small solutes across cellular membranes. Plants appear to express a surprisingly high number of AQP homologues. On the basis of sequence comparison, higher plant AQPs are classified into five subfamilies, the plasma membrane intrinsic proteins (PIPs), the tonoplast intrinsic protein (TIP), the NOD26-like intrinsic protein (NIP), the small basic intrinsic proteins (SIPs) and the uncharacterized X intrinsic proteins (XIPs). AQPs are thought to be involved in the regulation of transcellular water flow for long-distance transport in the root and leaf tissues. Their role is also critical for short-distance water transport and osmotic adjustments within a cell and between the cytoplasm and the cell wall space. However, some AQP isoforms play important roles in many other processes, such as gas and nutrient uptake and translocation, metalloid homeostasis, signal transduction. AQP abundance is regulated developmentally in a cell-specific manner and by environmental signals. The activity of AQPs is also regulated by different post-translational regulation mechanisms, which provide an efficient way for rapid and reversible regulation of the water membrane permeability.
The research project aims at understanding the function and regulation of plant AQPs at the cellular level and in the whole plant subjected to various environmental conditions.