EAGER: Advancing auxin transport research with patch clamp electrophysiology

University Of Wisconsin-Madison, Madison WI

Investigators

Abstract

Auxin is a hormone in plants that governs many basic physiological processes including cell growth. A special transport process moves auxin from cell to cell through plant organs. Understanding how this happens in detail, at the molecular and physical levels, has been a long-standing goal in the field of plant biology. If the auxin transport process were better understood, it could be possible to manipulate it to improve the growth of crops and other plants on which society depends. The project will use a biophysical technique called patch-clamp electrophysiology to determine how proteins belonging to the B subfamily of ATP-Binding-Cassette Transporters, contribute to the auxin transport process. Previous research has shown such proteins are required for auxin transport, but exactly what makes them necessary is not known, because it is not known if they actually transport auxin by themselves, assist other proteins, or in some other way are necessary for the process. By expressing such ABCB transporter proteins in animal cells, which do not possess auxin transport capability themselves, and then using the patch clamp technique to measure the flow of ions (electrically charged atoms) across the membranes of the animal cells, with and without auxin being present, the investigators will learn how ABCB transporters function, and this will lead to new, testable ideas about how auxin moves from cell to cell. The patch-clamp technique has not been used to study auxin transport before, so this project represents a new combination of biophysics and plant genetics. One expected result is a direct recording of the electric current caused by the charged auxin molecule as it passes through the ABCB transporter, or a definitive demonstration of its absence. A postdoctoral student will be trained to work at the interdisciplinary interface of biophysics and plant molecular biology during this project.