Peter Melcher was an invited seminar speaker in the horticulture department's seminar series at Cornell University.
His seminar was entitled, "Surfing the Xylem Pipeline: `Gels and Bordered Pits'".
Unlike animals, plants have cell walls and thus lack the capacity to have evolved a pump-like mechanism (such as a heart) to distribute water, minerals, nutrients to all their cells. Plants on the other hand rely on mostly "passive" forces to distribute these goods around their systems. In this presentation I focus on the water conducting transport system of plants (xylem).
Because water can withstand substantially large negative pressures it allows plants to power the movement of water through the xylem by evaporation from leaf surfaces. The negative pressures that these continuous water columns can withstand before breaking (cavitate) is critical for a plant to survive periods of water stress. Thus, I will specifically discuss factors that affect the cavitation threshold within the xylem of plants.
Contributed by Nancy Pierce