TY  - JOUR
AU  - Metzner, R.
AU  - Thorpe, M.R.
AU  - Breuer, U.
AU  - Blümler, P.
AU  - Schurr, U.
AU  - Schneider, H. U.
AU  - Schröder, W. H.
TI  - Contrasting dynamics of water and mineral nutrients in stems shown by stable isotope tracers and cryo-SIMS
JO  - Plant, cell & environment
VL  - 33
SN  - 0140-7791
CY  - Oxford [u.a.]
PB  - Wiley-Blackwell
M1  - PreJuSER-10545
SP  - 1393 - 1407
PY  - 2010
N1  - Record converted from VDB: 12.11.2012
AB  - Lateral exchange of water and nutrients between xylem and surrounding tissues helps to de-couple uptake from utilization in all parts of a plant. We studied the dynamics of these exchanges, using stable isotope tracers for water (H(2)(18)O), magnesium ((26)Mg), potassium ((41)K) and calcium ((44)Ca) delivered via a cut stem for various periods to the transpiration stream of bean shoots (Phaseolus vulgaris cv. Fardenlosa Shiny). Tracers were subsequently mapped in stem cross-sections with cryo-secondary ion mass spectrometry. The water tracer equilibrated within minutes across the entire cross-section. In contrast, the nutrient tracers showed a very heterogeneous exchange between xylem vessels and the different stem tissues, even after 4 h. Dynamics of nutrients in the tissues revealed a fast and extensive exchange of nutrients in the xylem parenchyma, with, for example, calcium being completely replaced by tracer in less than 5 min. Dilution of potassium tracer during its 30 s transit in xylem sap through the stem showed that potassium concentration was up-regulated over many hours, to the extent that some of it was probably supplied by phloem recirculation from the shoot.
KW  - Isotopes: analysis
KW  - Phaseolus: metabolism
KW  - Phaseolus: physiology
KW  - Plant Stems: metabolism
KW  - Plant Stems: physiology
KW  - Plant Transpiration
KW  - Water: metabolism
KW  - Xylem: metabolism
KW  - Xylem: physiology
KW  - Isotopes (NLM Chemicals)
KW  - Water (NLM Chemicals)
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
C6  - pmid:20444220
UR  - <Go to ISI:>//WOS:000279610200014
DO  - DOI:10.1111/j.1365-3040.2010.02157.x
UR  - https://juser.fz-juelich.de/record/10545
ER  -