Bio


Johannes received his BSc from the Leibniz Universität Hannover (Germany) in Plant Biotechnology in the Fruit Science laboratory of Prof. Moritz Knoche. Inspired by research on water relations of fruit in the Knoche laboratory, Johannes joined the group of Prof. Stephen Tyerman at The University of Adelaide (Australia) with funding through the German Academic Exchange Service. Initially, his work focused on hydraulic properties of grape clusters for which he received his MSc in Agricultural Science. Afterwards, he joined the ARC Centre of Excellence in Plant Energy Biology through the Tyerman laboratory and specialised in molecular plant physiology by studying the role of aquaporins in plant responses to drought for a PhD. He investigated aquaporins, which are molecular channels in plant membranes that provide a gating mechanism for water fluxes and other small molecules, through a combination of gene expression analysis and utilization of transgenic overexpression and CRISPR-Cas9 knockout lines. His work was funded by the highly competitive Adelaide Scholarship International and a Supplementary Scholarship provided by the ARC Centre of Excellence in Plant Energy Biology. In April 2018, Johannes joins the laboratory of Assoc. Prof. José Dinneny at Stanford University as a Postdoctoral Scholar.

Johannes research focuses on plant hydraulics from a molecular scale up to whole plants. He is interested on how plants perceive and adapt to changes in the environment in particular related to water. This ranges from developmental decisions to molecular control of water movement, for example through aquaporins. In José Dinneny's lab, he will continue work on hydropatterning, a phenomenon investigated in this laboratory previously.

Honors & Awards


  • Adelaide Scholarship International, The University of Adelaide (2013)
  • Supplementary Scholarship, ARC Centre of Excellence in Plant Energy Biology (2013)
  • R.N. Robertson Travelling Fellowship, Australian Society of Plant Scientists (2013)
  • ASVO conference scholarship, Australian Society of Viticulture and Oenology (2013)
  • DAAD Scholarship, German Academic Exchange Service (2011)

Boards, Advisory Committees, Professional Organizations


  • Member, Australian Society of Plant Scientists (2012 - Present)

Professional Education


  • Doctor of Philosophy, University Of Adelaide (2018)
  • Master of Science, University Of Adelaide (2013)
  • Bachelor of Science, Universitat Hannover (2010)

Lab Affiliations


All Publications


  • Water transport, perception, and response in plants JOURNAL OF PLANT RESEARCH Scharwies, J., Dinneny, J. R. 2019; 132 (3): 311–24
  • Water transport, perception, and response in plants. Journal of plant research Scharwies, J. D., Dinneny, J. R. 2019

    Abstract

    Sufficient water availability in the environment is critical for plant survival. Perception of water by plants is necessary to balance water uptake and water loss and to control plant growth. Plant physiology and soil science research have contributed greatly to our understanding of how water moves through soil, is taken up by roots, and moves to leaves where it is lost to the atmosphere by transpiration. Water uptake from the soil is affected by soil texture itself and soil water content. Hydraulic resistances for water flow through soil can be a major limitation for plant water uptake. Changes in water supply and water loss affect water potential gradients inside plants. Likewise, growth creates water potential gradients. It is known that plants respond to changes in these gradients. Water flow and loss are controlled through stomata and regulation of hydraulic conductance via aquaporins. When water availability declines, water loss is limited through stomatal closure and by adjusting hydraulic conductance to maintain cell turgor. Plants also adapt to changes in water supply by growing their roots towards water and through refinements to their root system architecture. Mechanosensitive ion channels, aquaporins, proteins that sense the cell wall and cell membrane environment, and proteins that change conformation in response to osmotic or turgor changes could serve as putative sensors. Future research is required to better understand processes in the rhizosphere during soil drying and how plants respond to spatial differences in water availability. It remains to be investigated how changes in water availability and water loss affect different tissues and cells in plants and how these biophysical signals are translated into chemical signals that feed into signaling pathways like abscisic acid response or organ development.

    View details for PubMedID 30747327

  • Association between water and carbon dioxide transport in leaf plasma membranes: assessing the role of aquaporins. Plant, cell & environment Zhao, M., Tan, H., Scharwies, J., Levin, K., Evans, J. R., Tyerman, S. D. 2017; 40 (6): 789-801

    Abstract

    The role of some aquaporins as CO2permeable channels has been controversial. Low CO2permeability of plant membranes has been criticized because of unstirred layers and other limitations. Here we measured both water and CO2permeability (Pos, PCO2) using stopped flow on plasma membrane vesicles (pmv) isolated from Pisum sativum (pea) and Arabidopsis thaliana leaves. We excluded the chemical limitation of carbonic anhydrase (CA) in the vesicle acidification technique for PCO2using different temperatures and CA concentrations. Unstirred layers were excluded based on small vesicle size and the positive correlation between vesicle diameter and PCO2. We observed high aquaporin activity (Pos0.06 to 0.22 cm s-1) for pea pmv based on all the criteria for their function using inhibitors and temperature dependence. Inhibitors of Posdid not alter PCO2. PCO2ranged from 0.001 to 0.012 cm s-1(mean 0.0079 + 0.0007 cm s-1) with activation energy of 30.2 kJ mol-1. Intrinsic variation between pmv batches from normally grown or stressed plants revealed a weak (R2 = 0.27) positive linear correlation between Posand PCO2. Despite the low PCO2, aquaporins may facilitate CO2transport across plasma membranes, but probably via a different pathway than for water.

    View details for DOI 10.1111/pce.12830

    View details for PubMedID 27620674

  • Comparison of isohydric and anisohydric Vitis vinifera L. cultivars reveals a fine balance between hydraulic resistances, driving forces and transpiration in ripening berries FUNCTIONAL PLANT BIOLOGY Scharwies, J. D., Tyerman, S. D. 2017; 44 (3): 324-338

    View details for DOI 10.1071/FP16010

    View details for Web of Science ID 000395563300005

  • Russeting and Relative Growth Rate Are Positively Related in 'Conference' and 'Condo' Pear HORTSCIENCE Scharwies, J. D., Grimm, E., Knoche, M. 2014; 49 (6): 746-749