Hydraulic conductance and K+ transport into the xylem depend on radial volume flow, rather than on xylem pressure, in roots of intact, transpiring maize seedlings
Article first published online: 5 NOV 2008
© The Authors (2008). Journal compilation © New Phytologist (2008)
Volume 181, Issue 2, pages 361–373, January 2009
How to Cite
Wegner, L. H. and Zimmermann, U. (2009), Hydraulic conductance and K+ transport into the xylem depend on radial volume flow, rather than on xylem pressure, in roots of intact, transpiring maize seedlings. New Phytologist, 181: 361–373. doi: 10.1111/j.1469-8137.2008.02662.x
- Issue published online: 16 DEC 2008
- Article first published online: 5 NOV 2008
- Received: 29 May 2008; Accepted: 8 September 2008
- 1976. Transport through roots. In: LüttgeU, PitmanMG, eds. Encyclopedia of plant physiology, new series 2B. Berlin, Germany: Springer, 129–156. .
- 1970. A comparison of potassium translocation in excised roots and intact maize seedlings. Planta 93: 227–232. ,
- 1990. Comparative measurements of the xylem pressure of Nicotiana plants by means of the pressure bomb and pressure probe. Planta 182: 325–338. ,
- 2007. A model based on facilitated passive diffusion is needed to describe root water entry through aquaporins. Plant Signaling & Behaviour 2: 285–287. , , .
- 1988. Root excision decreases nutrient absorption and gas fluxes. Plant Physiology 87: 794–796. , .
- 2007. Comparison between gradient-dependent hydraulic conductivities of roots using the root pressure probe: the role of pressure propagations and implications for the relative roles of parallel radial pathways. Plant, Cell & Environment 30: 861–874. , , , .
- 2001. Aquaporins constitute a large and highly divergent protein family in maize. Plant Physiology 125: 1206–1215. , , , ,
- 1993. Roots and the delivery of solutes to the xylem. Philosophical Transactions of the Royal Society London Series B 341: 5–17. .
- 1963. Water relations of plant cells. Advances in Botanical Research 1: 279–326.
- 1976. Electrochemical gradients and K+ and Cl− fluxes in excised corn roots. Plant Physiology 57: 129–136. ,
- 1999. Potassium translocation into the root xylem. Plant Biology 1: 36–45. .
- 1984. Trans-root potential in roots of Plantago media L. as affected by hydrostatic pressure: the induction of an O2 deficient root core. Plant and Cell Physiology 25: 643–655. ,
- 1971. The movement of ions to the xylem exudate of maize roots. I. Profiles of membrane potential and potassium activity across the root. Journal of Experimental Botany 22: 434–444. , .
- 2002. Water entry into detached root systems saturates with increasing externally applied pressure; a result inconsistent with models of simple passive diffusion. Physiologia Plantarum 115: 406–416. ,
- 1992. Adaptation of potassium translocation into the shoot of maize (Zea mays) to shoot demand: evidence for xylem loading as a regulating step. Physiologia Plantarum 86: 263–268. ,
- 1992. Effect of root zone temperature and shoot demand on uptake and xylem transport of macronutrients in maize (Zea mays L.) Journal of Experimental Botany 44: 1695–1701. , ,
- 1977. Effects of coupled solute and water flow in plant roots with special reference to Brouwer's experiment. Journal of Experimental Botany 28: 71–77.
- 1998. Identification and disruption of a plant Shaker-like outward channel involved in K+ release into the xylem sap. Cell 94: 647–655. , , , , , , , ,
- 2006. Localization and quantification of plasma membrane aquaporin expression in maize primary root: a clue to understanding their role as cellular plumbers. Plant Molecular Biology 62: 305–323. , , , ,
- 2002. The role of aquaporins in root water uptake. Annals of Botany 90: 301–313. ,
- 2007. During measurements of root hydraulics with pressure probes, the contribution of unstirred layers is minimized in the pressure relaxation mode: comparison with pressure clamp and high-pressure flowmeter. Plant, Cell & Environment 30: 845–860. , ,
- 2000. The delivery of salts to the xylem. Three types of anion conductance in the plasmalemma of the xylem parenchyma of barley. Plant Physiology 122: 243–254. ,
- 2002. Loading of nitrate into the xylem: apoplastic nitrate controls the voltage dependence of X-QUAC, the main anion conductance in xylem-parenchyma cells of barley roots. Plant Journal 30: 133–142. , , ,
- 1971. Lateral transport of ions into the xylem of corn roots. II Evaluation of a stelar pump. Plant Physiology 48: 118–124. , ,
- 2006. Intracellular K+ sensing of SKOR, a shaker-type K+ channel from Arabidopsis. Plant Journal 46: 260–268. , ,
- 1964. Effect of water movement on ion movement into the xylem of tomato roots. Plant Physiology 39: 494–501.
- 1998. Cell marking in Arabidopsis thaliana and its application to patch–clamp studies. Plant Journal 15: 843–851. , , , , , , , , .
- 2004. Chilling responses of maize (Zea mays L.) seedlings: root hydraulic conductance, abscisic acid, and stomatal conductance. Journal of Experimental Botany 55: 1751–1760. , , .
- 1980. Studies of root function in Zea mays L. I Apparatus and methods. Canadian Journal of Botany 59: 351–360. .
- 1985a. Studies of root function in Zea mays. III. Xylem sap composition at maximum root pressure provides evidence of active transport into the xylem and a measurement of the reflection coefficient of the root. Plant Physiology 77: 162–167. .
- 1985b. Studies on root function in Zea mays. IV. Effects of applied pressure on the hydraulic conductivity and volume flow through the excised root. Plant Physiology 77: 168–174. .
- 1988. Water transport in and to roots. Annual Review of Plant Physiology and Plant Molecular Biology 38: 245–265. .
- 1984. Hydraulic resistance of plants. II. Effects of rooting medium, and time of day, in barley and lupin. Australian Journal of Plant Physiology 11: 341–350. ,
- 1982. Transport across plant roots. Quaterly Reviews of Biophysics 15: 481–554. .
- 1995. Inward and outward K+-selective currents in the plasma membrane of protoplasts from maize root cortex and stele. Plant Journal 8: 811–825. ,
- 1993. Transpiration induces radial turgor pressure gradients in wheat and maize roots. Plant Physiology 103: 493–500. , , , ,
- 1984. Pressure-induced water and solute flow through plant roots. Journal of Experimental Botany 35: 869–881. , .
- 1997a. Diurnal variation in the radial reflection coefficient of intact maize roots determined with the xylem pressure probe. Journal of Experimental Botany 48: 2045–2053. , , , , , , ,
- 1997b. Xylem and cell turgor pressure measurements in intact roots of glycophytes: transpiration induces a change in the radial and cellular reflection coefficients. Plant, Cell & Environment 20: 221–229. , ,
- 1998. How does water get through roots? Journal of Experimental Botany 49: 775–788. , .
- 2001. Partitioning of nutrient transport processes in roots. Journal of Experimental Botany 52 Roots Special Issue: 445–457. , .
- 2006. Structural mechanism of plant aquaporin gating. Nature 439: 688–694. , , , , , , ,
- 2005. Roles of aquaporins in root responses to irrigation. Plant and Soil 274: 141–161. , , , .
- 2003. Molecular mechanisms and regulation of K+ transport in higher plants. Annual Review of Plant Biology 54: 575–603. ,
- 2004. Gating of water channels (aquaporins) in cortical cells of young corn roots by mechanical stimuli (pressure pulses): effects of ABA and of HgCl2. Journal of Experimental Botany 55: 411–422. , ,
- 1982. Water uptake and flow in roots. In: LangeOL, NobelPS, OsmondCB, ZieglerH, eds. Encyclopedia of plant physiology, Vol. 12B. Berlin, Germany: Springer-Verlag, 79–109. .
- 1997. Properties of two outward-rectifying channels in root xylem parenchyma cells suggest a role in K+ homeostasis and long-distance signaling. Plant Physiology 115: 1707–1719. , .
- 1999. Activation kinetics of the K+ outward rectifying conductance (KORC) in xylem parenchyma cells from barley roots. Journal of Membrane Biology 170: 103–119. , .
- 1994. Ion channels in the xylem parenchyma of barley roots. Plant Physiology 105: 799–813. ,
- 2007. On-line measurements of ion relations in the xylem sap of intact plants. In: SattelmacherB, HorstWJ, eds. The apoplast of higher plants: compartment of transport, storage and reaction. Dordrecht, the Netherlands: Kluwer Academic Publishers, 207–220. , ,
- 1998. Simultaneous recording of xylem pressure and trans-root potential in roots of intact glycophytes using a novel xylem pressure probe technique. Plant, Cell & Environment 21: 849–865. ,
- 2002. On-line measurements of K+ activity in the tensile water of the xylem conduit of higher plants. Plant Journal 32: 409–417. ,
- 2007. An electrogenic pump in the xylem parenchyma of barley roots. Physiologia Plantarum 129: 397–406. , ,
- 1998. Apoplastic transport across young maize roots: effect of the endodermis. Planta 206: 7–19. ,
- 2001. Pressure probe measurements of the driving forces for water transport in intact higher plants: effects of transpiration and salinity. In: LäuchliA, LüttgeU, eds. Salinity: environment-plants-molecules. Dordrecht, the Netherlands: Kluwer Academic Publishers, 249–270. , , , .
- 2004. Water ascent in tall trees: does evolution of land plants rely on a highly metastable state? (Tansley Review). New Phytologist 162: 575–615. , , ,
- 1978. Physical aspects of water relations of plant cells. Advances in Botanical Research 6: 45–117. ,