期刊
PLANT AND SOIL
卷 461, 期 1-2, 页码 69-89出版社
SPRINGER
DOI: 10.1007/s11104-019-04376-4
关键词
Method; Modelling; Nutrient uptake; Phosphorus mobilisation; Soil solution
资金
- ERC Consolidator grant [646,809]
- BBSRC SARISA [BB/L025620/1]
- EPSRC [EP/M020355/1]
- BBSRC SARIC [BB/P004180/1]
- NERC [NE/L00237/1]
- [NE/K01093X/1]
- BBSRC [BB/I024283/1, BB/L025620/1] Funding Source: UKRI
This study utilized a combination of experimental and modeling approaches to investigate the mechanism of organic acid exudation by plant roots and its impact on phosphate solubilization and availability. The results showed that while citrate exudation by roots had some influence on phosphate uptake, it was not significant enough to significantly enhance P absorption.
Aims Organic acid exudation by plant roots is thought to promote phosphate (P) solubilisation and bioavailability in soils with poorly available nutrients. Here we describe a new combined experimental (microdialysis) and modelling approach to quantify citrate-enhanced P desorption and its importance for root P uptake. Methods To mimic the rhizosphere, microdialysis probes were placed in soil and perfused with citrate solutions (0.1, 1.0 and 10 mM) and the amount of P recovered from soil used to quantify rhizosphere P availability. Parameters in a mathematical model describing probe P uptake, citrate exudation, P movement and citrate-enhanced desorption were fit to the experimental data. These parameters were used in a model of a root which exuded citrate and absorbed P. The importance of soil citrate-P mobilisation for root P uptake was then quantified using this model. Results A plant needs to exude citrate at a rate of 0.73 mu mol cm(-1) of root h(-1) to see a significant increase in P absorption. Microdialysis probes with citrate in the perfusate were shown to absorb similar quantities of P to an exuding root. Conclusion A single root exuding citrate at a typical rate (4.3 x 10(-5) mu mol m(-1) of root h(-1)) did not contribute significantly to P uptake. Microdialysis probes show promise for measuring rhizosphere processes when calibration experiments and mathematical modelling are used to decouple microdialysis and rhizosphere mechanisms.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据