Research output: Contribution to Journal/Magazine › Journal article › peer-review
Xylem sap calcium concentrations do not explain liming-induced inhibition of legume gas exchange. / Rothwell, Shane A.; Dodd, Ian C.
In: Plant and Soil, Vol. 382, No. 1-2, 09.2014, p. 17-30.Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Xylem sap calcium concentrations do not explain liming-induced inhibition of legume gas exchange
AU - Rothwell, Shane A.
AU - Dodd, Ian C.
PY - 2014/9
Y1 - 2014/9
N2 - Liming is considered normal agricultural practise for remediating soil acidity and improving crop productivity; however recommended lime applications can reduce yield. We tested the hypothesis that elevated xylem sap Ca2+ limited gas exchange of Phaseolus vulgaris L. and Pisum sativum L. plants that exhibited reduced shoot biomass and leaf area when limed.We used Scholander and whole-plant pressure chamber techniques to collect root and leaf xylem sap, a calcium-specific ion-selective electrode to measure xylem sap Ca2+, infra-red gas analysis to measure gas exchange of limed and unlimed (control) plants, and a detached leaf transpiration bioassay to determine stomatal sensitivity to Ca2+.Liming reduced shoot biomass, leaf area and leaf gas exchange in both species. Root xylem sap Ca2+ concentration was only increased in P. vulgaris and not in P. sativum. Detached leaves of both species required 5 mM Ca2+ supplied to via the transpiration stream to induce stomatal closure, however, maximum in vivo xylem sap Ca2+ concentrations of limed plants was only 1.7 mM and thus not high enough to influence stomata.We conclude that an alternative xylem-borne antitranspirant other than Ca2+ decreases gas exchange of limed plants.
AB - Liming is considered normal agricultural practise for remediating soil acidity and improving crop productivity; however recommended lime applications can reduce yield. We tested the hypothesis that elevated xylem sap Ca2+ limited gas exchange of Phaseolus vulgaris L. and Pisum sativum L. plants that exhibited reduced shoot biomass and leaf area when limed.We used Scholander and whole-plant pressure chamber techniques to collect root and leaf xylem sap, a calcium-specific ion-selective electrode to measure xylem sap Ca2+, infra-red gas analysis to measure gas exchange of limed and unlimed (control) plants, and a detached leaf transpiration bioassay to determine stomatal sensitivity to Ca2+.Liming reduced shoot biomass, leaf area and leaf gas exchange in both species. Root xylem sap Ca2+ concentration was only increased in P. vulgaris and not in P. sativum. Detached leaves of both species required 5 mM Ca2+ supplied to via the transpiration stream to induce stomatal closure, however, maximum in vivo xylem sap Ca2+ concentrations of limed plants was only 1.7 mM and thus not high enough to influence stomata.We conclude that an alternative xylem-borne antitranspirant other than Ca2+ decreases gas exchange of limed plants.
KW - Calcium
KW - Lime
KW - Pisum sativum
KW - Phaseolus vulgaris
KW - Stomatal conductance
KW - Xylem sap
KW - STOMATAL CONDUCTANCE
KW - ABSCISIC-ACID
KW - SOIL ACIDIFICATION
KW - RICINUS-COMMUNIS
KW - FLOW-RATE
KW - WATER
KW - PLANTS
KW - SHOOT
KW - LIME
KW - TRANSPIRATION
U2 - 10.1007/s11104-014-2118-5
DO - 10.1007/s11104-014-2118-5
M3 - Journal article
VL - 382
SP - 17
EP - 30
JO - Plant and Soil
JF - Plant and Soil
SN - 0032-079X
IS - 1-2
ER -