Start of funding 01.01.2019

Contribution of xylem surfactants to water transport under negative pressure

Prof. Dr. Berhard Schuldt
University of Würzburg
Julius-von-Sachs-Institute for Biosciences

Prof. Dr. H. Jochen Schenk
California State University, Fullerton
Department of Biological Science



In any plant, water is transported under negative pressure over long distances. Under a given drought-exposure, increasing negative xylem tensions might result in the formation of gas bubbles in the hydraulic system, which causes a break-down of the long-distance water transport. Although there is a general consensus about the capillary driving forces of the ascent of sap according to the cohesion-tension theory, our understanding of water uptake and long-distance transport in plants remains controversial. Recent results show that xylem surfactants support water transport under negative pressure by coating hydrophobic surfaces and nanobubbles, thereby keeping the latter below a critical size at which bubbles could expand. Of special importance are amphiphilic xylem lipids and proteins. The present project aims (1) to identify the origin of xylem amphiphilic lipids and proteins which have been observed in xylem sap, and to (2) monitor if they accumulate over time in xylem.