Research output: Contribution to Journal/Magazine › Journal article › peer-review
<mark>Journal publication date</mark> | 09/2014 |
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<mark>Journal</mark> | Plant and Soil |
Issue number | 1-2 |
Volume | 382 |
Number of pages | 14 |
Pages (from-to) | 17-30 |
Publication Status | Published |
<mark>Original language</mark> | English |
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.