Eric Kramer, faculty in Science, Mathematics, and Computing, and senior Ethan Ackelsberg ’12 authored a second paper together, “Do Vacuoles Obscure the Evidence for Auxin Homeostasis?” published in the January issue of Molecular Plant.
This latest paper continues Eric and Ethan’s research on auxin, extending the work done last year and published in the scientific journal Frontiers, “Auxin Metabolism Rates and Implications for Plant Development.” Both papers are concerned with the quantification of previously vague ideas about auxin production and action within the plant.
The plant hormone auxin regulates many events in plant growth and development. When it accumulates to a high level inside the nucleus of a single root cell, it triggers events such as the growth of a new root from the side of an existing root.
Eric and Ethan’s work analyzes the importance of the plant vacuole to this process. The vacuole, a water-filled sack inside each plant cell, can occupy 90 percent of the cell volume in large cells. The auxin concentration in a cell nucleus depends critically on whether or not it can also enter the vacuole.
Ethan extracted and analyzed data from other papers that had previously measured the auxin content of plant tissues. The two concluded that the data were consistent with auxin exclusion from vacuoles, implying a much higher concentration of auxin in the cell nucleus than had previously been recognized.
Many research groups around the world are trying to understand auxin signaling in the nucleus. Eric and Ethan are contributing to that effort.