FACULT Y SPOTLIGHT
Going with the Flow:
John Sperry
Retiring botanist studied how plant’s xylem tissue carries phenomenal amounts of water to tree leaves where it evaporates and influences regional weather patterns
J
ohn Sperry grew up in Normal, Illinois, but his interest in plants–eventually their vascular function–would propel him into work that was far from standard in botany via Duke University and, eventually Harvard where he earned his PhD. At Harvard his Swiss-born mentor Martin Zimmermann was considered among the top plant physiologists in the world and a scholar whom Sperry credits with, more than anyone else, “showing him how” to do research. Even so Zimmermann strongly questioned the ability of Sperry’s proposed, novel technique to measure the blockage of vascular flow by cavitation. It was the ultimate success of that technique and new discoveries of how vascular tissues, or xylem in particular, 4
function in conducting water and dissolved nutrients upward from roots, that would become the subject of Sperry’s PhD thesis. And it was that thesis and the questions it spawned that laid the foundation of all of the research he would do for the next thirty-plus years, including a stint as a post-doc at the University of Vermont prior to his arrival at the University of Utah in 1989. “As humans, we are acutely aware of the importance of maintaining vascular function,” Sperry’s Research Statement reads. “To plants it is no less critical. My laboratory investigates hydro-vascular structure and function in plants in relation to their ecology, physiology, and evolution.” The scale of this function in plants is, he explains, a “phenomenal process. The sheer quantity of water moved through plants often exceeds
