EAGER: Advancing auxin transport research with patch clamp electrophysiology

生长素是植物体内的一种激素，它控制着包括细胞生长在内的许多基本生理过程。一种特殊的运输过程通过植物器官将生长素从一个细胞转移到另一个细胞。在分子和物理水平上详细了解这是如何发生的，一直是植物生物学领域的长期目标。如果更好地了解生长素的运输过程，就有可能操纵它来改善作物和社会赖以生存的其他植物的生长。该项目将使用一种名为膜片钳电生理学的生物物理技术来确定属于ATP结合盒转运体B亚家族的蛋白质如何参与生长素的运输过程。以前的研究表明，这种蛋白质是生长素运输所必需的，但究竟是什么使它们成为必需的尚不清楚，因为还不知道它们实际上是自己运输生长素，还是辅助其他蛋白质，或者以某种其他方式对这一过程是必要的。通过在本身不具有生长素运输能力的动物细胞中表达这种ABCB转运蛋白，然后使用膜片钳技术来测量在生长素存在和不存在的情况下穿过动物细胞膜的离子(带电原子)的流动，研究人员将了解ABCB转运蛋白是如何发挥作用的，这将导致关于生长素如何从细胞转移到细胞的新的、可测试的想法。膜片钳技术以前没有被用来研究生长素的运输，所以这个项目代表了生物物理学和植物遗传学的新结合。一个预期的结果是，当带电的生长素分子通过ABCB转运体时，直接记录它所产生的电流，或者明确证明它不存在。在这个项目中，一名博士后将接受培训，在生物物理学和植物分子生物学的交叉学科界面上工作。

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.