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Dynamics, thermodynamics and kinetics of exudates: crucial issues in understanding rhizosphere processes

A Commentary to this article was published on 04 December 2014

The Original Article was published on 04 June 2014

Abstract

Background

In this issue, Schenkeveld and coworkers described the potential of phytosiderophores (a class of root exudates) to mobilize metals in the rhizosphere by an equilibrium modelling approach.

Scope

The rhizosphere is a complex and dynamic environment where several different organic and inorganic compounds coexist. Due to the different concentration and chemical characteristics there might be competitive and synergistic interactions. However the rhizosphere is strongly influenced by root activity: water and nutrient uptake, root respiration that might modify the pH and redox status of the rhizosphere. Thus, how does the complexity of the system and the dynamics influence the thermodynamics of the single process? Can chemical equilibria be really reached in the rhizosphere? Issues related to kinetics vs thermodynamics are discussed. The study of the single processes is important but more complex researches, being thus more realistic (i.e. field-like conditions), are necessary. Hence, what are the available tools/methods in rhizosphere research? What are the drawbacks? How can the results of these methods be related to thermodynamic and kinetic models?

Conclusions

Besides stimulating further awareness around the rhizosphere complexity, tentative answers are given highlighting the future challenges in rhizosphere research, essential knowledge for the development of agronomic practices ensuring a better exploitation of soil endogenous resources of nutrients by crops.

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Acknowledgments

Research supported by grants from Italian MIUR (FIRB - Programma “Futuro in Ricerca”) and Free University of Bolzano (TN5056 - TN2023).

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Correspondence to Stefano Cesco.

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Responsible Editor: Michael A. Grusak.

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Terzano, R., Cesco, S. & Mimmo, T. Dynamics, thermodynamics and kinetics of exudates: crucial issues in understanding rhizosphere processes. Plant Soil 386, 399–406 (2015). https://doi.org/10.1007/s11104-014-2308-1

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Keywords

  • Root exudates
  • Rhizosphere
  • Dynamics
  • Thermodynamics vs. kinetics
  • Nutrients