Hydrogel Control of Xylem Hydraulic Resistance in Plants
Maciej A. Zwieniecki(Harvard University)
USA | Science
2001.02.09 | 바로가기
flow rate, hydraulic resistance in plants
Cited by 572
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Science 09 Feb 2001: Vol. 291, Issue 5506, pp. 1059-1062
Maciej A. Zwieniecki*, Peter J. Melcher, N. Michele Holbrook
Organismic and Evolutionary Biology, Harvard University, 16 Divinity Avenue, Cambridge, MA 02138, USA.
Increasing concentrations of ions flowing through the xylem of plants produce rapid, substantial, and reversible decreases in hydraulic resistance. Changes in hydraulic resistance in response to solution ion concentration, pH, and nonpolar solvents are consistent with this process being mediated by hydrogels. The effect is localized to intervessel bordered pits, suggesting that microchannels in the pit membranes are altered by the swelling and deswelling of pectins, which are known hydrogels. The existence of an ion-mediated response breaks the long-held paradigm of the xylem as a system of inert pipes and suggests a mechanism by which plants may regulate their internal flow regime.