title: The holistic rhizosphere: integrating zones, processes, and semantics in the soil influenced by roots.
abstract: Despite often being conceptualized as a thin layer of soil around roots, the rhizosphere is actually a dynamic system of interacting processes. Hiltner originally defined the rhizosphere as the soil influenced by plant roots. However, soil physicists, chemists, microbiologists, and plant physiologists have studied the rhizosphere independently, and therefore conceptualized the rhizosphere in different ways and using contrasting terminology. Rather than research-specific conceptions of the rhizosphere, the authors propose a holistic rhizosphere encapsulating the following components: microbial community gradients, macroorganisms, mucigel, volumes of soil structure modification, and depletion or accumulation zones of nutrients, water, root exudates, volatiles, and gases. These rhizosphere components are the result of dynamic processes and understanding the integration of these processes will be necessary for future contributions to rhizosphere science based upon interdisciplinary collaborations. In this review, current knowledge of the rhizosphere is synthesized using this holistic perspective with a focus on integrating traditionally separated rhizosphere studies. The temporal dynamics of rhizosphere activities will also be considered, from annual fine root turnover to diurnal fluctuations of water and nutrient uptake. The latest empirical and computational methods are discussed in the context of rhizosphere integration. Clarification of rhizosphere semantics, a holistic model of the rhizosphere, examples of integration of rhizosphere studies across disciplines, and review of the latest rhizosphere methods will empower rhizosphere scientists from different disciplines to engage in the interdisciplinary collaborations needed to break new ground in truly understanding the rhizosphere and to apply this knowledge for practical guidance.
authors.affiliation: Centre for Plant Integrative Biology, School of Biosciences, University of Nottingham, Sutton Bonington Campus, LE12 5RD, UK larry.york@rootbiologist.com.
authors.forename: Larry M
authors.identifier: 0000-0002-1995-9479
authors.initials: LM
authors.lastname: York
authors.affiliation: Division of Soil Hydrology, Georg-August University of Göttingen, 37077 Göttingen, Germany.
authors.forename: Andrea
authors.initials: A
authors.lastname: Carminati
authors.affiliation: Centre for Plant Integrative Biology, School of Biosciences, University of Nottingham, Sutton Bonington Campus, LE12 5RD, UK.
authors.forename: Sacha J
authors.initials: SJ
authors.lastname: Mooney
authors.affiliation: Centre for Plant Integrative Biology, School of Biosciences, University of Nottingham, Sutton Bonington Campus, LE12 5RD, UK.
authors.forename: Karl
authors.initials: K
authors.lastname: Ritz
authors.affiliation: Centre for Plant Integrative Biology, School of Biosciences, University of Nottingham, Sutton Bonington Campus, LE12 5RD, UK.
authors.forename: Malcolm J
authors.initials: MJ
authors.lastname: Bennett
mesh_terms: D018517:Plant Roots / Q000254:growth & development / Q000502:physiology*; D058441:Rhizosphere; D012987:Soil / Q000737:chemistry*; D009626:Terminology as Topic
chemical_list: D012987:Soil
keywords: Depletion; microbial; mucilage; nutrient; plant; rhizodeposition; root; soil.