Research activities

Functional plant morphology

Our research addresses functional plant morphology, especially with respect to plant water relations. By integrating functional, anatomical, physiological, and ecological aspects of plant water transport, we aim to address the longstanding question of water transport under negative pressure. Special attention is given to the following topics:
(1)    Effects of drought stress on water transport.
(2)    The morphology and function of bordered pit membranes between water conducting cells.
(3)    The location, origin, and functional role of insoluble, amphiphilic lipids in the hydraulic transport system of a wide range of plants.
Our research on water transport in plants has implications for water conservation and irrigation, drought-induced tree mortality, the effects of climate change on plant growth and forest responses, and biomimetic applications such as man-made fluid transport systems under negative pressure.
Methods applied include light microscopy, electron microscopy, confocal laser scanning microscopy, atomic force microscopy, tomography, and nuclear magnetic resonance imaging. Besides anatomical observations, we apply ecophysiological measurements in the field and in the lab.

Aluminium accumulation in plants

We are interested in studying the distribution, ecology, physiology, and evolution of aluminium (Al) accumulation in plants. This trait, which can be defined as the uptake of Al in aboveground plant tissues in concentrations well above 1,000 ppm, builds on our earlier systematic surveys and is mainly focussed on tropical plants.
A central question is how Al accumulators and excluders co-exist and compete with each other across various vegetation and soil types. Understanding how exactly accumulators take up Al and detoxify it in their leaves, bark, and wood tissue may provide useful information to better understand Al toxicity, which represents one of the major problems for cultivating various crops in acidic soils worldwide.

Current projects

•    DFG individual research grant (JA 2174/5-1): “Surfactants may shed novel light on water transport in plants under negative pressure”; 1 September 2018 - 31 August 2021.
•    National Science Foundation: “Apoplastic lipids in xylem of vascular plants: Composition, locations, origins, and possible functions”. Join application with Prof. Dr. Jochen Schenk (PI); I am co-PI. April 2018 –April 2021.
•    Centre for the study of Biodiversity in Amazonia (CEBA): Bordered pits provide a mechanistic understanding of embolism resistance in branch and leaf xylem of tropical rainforest trees from French Guyana. Joint application with Dr. Patrick Heuret (INRA, UMR Amap, Montpellier, France). 1 April 2018 – 31 December 2019.

    Selection of previous projects

    •    National Science Foundation: “Biology, chemistry, and physics of xylem surfactants”. Joint application with Prof. Dr. H.J. Schenk (Fullerton State University, California, USA) as PI.
    •    German Science Foundation, DFG: “Evolutionary and functional traits of parenchyma in the hydraulic architecture of plants”, 1 April 2013 – 31 December 2016.
    •    Ministry for Science, Research, and the Arts, Baden-Wurttemberg, Germany, Juniorprofessoren-Programm: “Aluminium uptake in Symplocos trees and sustainable use of dye plants by Indonesian weavers”, January 2013 - September 2016.
    •    DAAD: “Xylem analysis of crop plants under drought”, joint application with the University of Belgrade (Serbia), January 2013 – December 2014.
    •    National Science Foundation: “Water in, air out: Mechanisms of xylem embolism repair in seed plants”. Prof. Dr. H.J. Schenk (Fullerton State University, California, USA) as PI; 1/4/2012 – 31/3/2015.
    •    German Science Foundation, DFG: “International Workshop on Plant Hydraulic Techniques”, Ulm University, 17-19 September 2014.
    •    Ministry for Science, Research, and the Arts, Baden-Wurttemberg, Germany, Juniorprofessorenprogramm: “The relationship between microscopic hydraulic networks and water transport in plants”. 1 November 2009 – 30 April 2013.
    •    European Science Foundation (ESF): “The significance of xylem hydraulic plasticity for reconstructing past environments”, organisation of a workshop at Kippel (Switzerland) with Dr. P. Fonti (WSL, Switzerland), 15-17 May 2012.
    •    Royal Society International Joint Project, UK: “The physiology and anatomy of drought resistance in conifers”, joint project with Dr S. Delzon (University of Bordeaux, France), February 2009 – 31 May 2012.
    •    Australian Research Council – New Zealand Research Network for Vegetation Function Working Group: “Xylem Functional Traits”, joint application with Dr. B. Choat, October 2009.
    •    NERC-New Investigators competition, UK: “Structure and function of pit membranes in water conduction pathways of plants: combining novel microscopy techniques with xylem hydraulic experiments”, 23 September 2006 – 22 May 2008.
    •    Royal Society Research Grant, UK: “How do vessel pits enable water flow? Evidence from atomic force microscopy (AFM) and X-ray computed tomography (microCT) of wood”, 4 August 2006 – 3 August 2007.
    •    The Daiwa Anglo-Japanese Foundation, UK: “Electron microscope observations of pit membranes with central thickenings: an overlooked wood anatomical character in angiosperms”, 22 november 2004 - 22 november 2005.
    •    “Krediet aan Navorsers”, F.W.O.-Flanders, Belgium: “The distribution, function and systematic significance of selected wood and leaf anatomical characters in flowering plants”, 01/01/2003 - 03/07/2004.