Regulation of aquaporins in plants under stress.

Aquaporins (AQP) are channel proteins belonging to the Major Intrinsic Protein (MIP) superfamily that play an important role in plant water relations. The main role of aquaporins in plants is transport of water and other small neutral molecules across cellular biological membranes. AQPs have remarkable features to provide an efficient and often, specific water flow and enable them to transport water into and out of the cells along the water potential gradient.

Responses of hybrid aspen over-expressing a PIP2;5 aquaporin to low root temperature.

Aquaporins mediate the movement of water across cell membranes. Plasma membrane intrinsic protein 2;5 from Populus trichocarpa×deltoides (PtdPIP2;5) was previously demonstrated to be a functionally important water conducting aquaporin. To study the relevance of aquaporin-mediated root water transport at low temperatures, we generated transgenic Populus tremula×alba over-expressing PtdPIP2;5 under control of the maize ubiquitin promoter, and compared the physiological responses and water transport properties of the PtdPIP2;5 over-expressing lines (PtdPIP2;5ox) with wild-type plants.