title: Elucidating rhizosphere processes by mass spectrometry - A review.
abstract: The presented review discusses state-of-the-art mass spectrometric methods, which have been developed and applied for investigation of chemical processes in the soil-root interface, the so-called rhizosphere. Rhizosphere soil's physical and chemical characteristics are to a great extent influenced by a complex mixture of compounds released from plant roots, i.e. root exudates, which have a high impact on nutrient and trace element dynamics in the soil-root interface as well as on microbial activities or soil physico-chemical characteristics. Chemical characterization as well as accurate quantification of the compounds present in the rhizosphere is a major prerequisite for a better understanding of rhizosphere processes and requires the development and application of advanced sampling procedures in combination with highly selective and sensitive analytical techniques. During the last years, targeted and non-targeted mass spectrometry-based methods have emerged and their combination with specific separation methods for various elements and compounds of a wide polarity range have been successfully applied in several studies. With this review we critically discuss the work that has been conducted within the last decade in the context of rhizosphere research and elemental or molecular mass spectrometry emphasizing different separation techniques as GC, LC and CE. Moreover, selected applications such as metal detoxification or nutrient acquisition will be discussed regarding the mass spectrometric techniques applied in studies of root exudates in plant-bacteria interactions. Additionally, a more recent isotope probing technique as novel mass spectrometry based application is highlighted.
authors.affiliation: Division of Analytical Chemistry, Department of Chemistry, University of Natural Resources and Life Sciences-BOKU, Vienna, Austria.
authors.forename: Ariana
authors.initials: A
authors.lastname: Rugova
authors.affiliation: Department of Forest and Soil Sciences, Rhizosphere Ecology and Biogeochemistry Group, University of Natural Resources and Life Sciences-BOKU, Vienna, Austria.
authors.forename: Markus
authors.initials: M
authors.lastname: Puschenreiter
authors.affiliation: Institute of Analytical Chemistry, Faculty of Chemistry, University of Vienna, Vienna, Austria.
authors.forename: Gunda
authors.initials: G
authors.lastname: Koellensperger
authors.affiliation: Division of Analytical Chemistry, Department of Chemistry, University of Natural Resources and Life Sciences-BOKU, Vienna, Austria. Electronic address: stephan.hann@boku.ac.at.
authors.forename: Stephan
authors.initials: S
authors.lastname: Hann
mesh_terms: D001419:Bacteria; D013058:Mass Spectrometry; D018517:Plant Roots / Q000737:chemistry; D058441:Rhizosphere; D012987:Soil / Q000737:chemistry*; D012988:Soil Microbiology
chemical_list: D012987:Soil
keywords: Mass spectrometry; Rhizosphere; Root exudates; Separation techniques