Biophysical Plant Physiology Lectures [WZ4632] and Seminar [WZ4633]

Lecturer: Dr. Mohanned Abdalla, Prof. Dr. Mutez Ahmed

The following topics are covered: 
• Introduction 
• Cells and diffusion (Cell structure [Generalized plant cell, Leaf anatomy, root anatomy, vascular tissue], Diffusion [Fick’s law], membrane structure and permeability) 
• Water physical properties (surface tension, capillary rise, water potential [matric, hydrostatic, osmotic]) 
• Water potential and plant cells (pressure-volume curve, incipient plasmolysis) 
• Roots and fluxes (root hairs, radial water flow across root [apoplastic, symplastic], radial conductance and resistance) 
• Leaves and fluxes (stomata [stomatal conductance and resistance, intercellular air space], CO2 conductances and resistances) 
• Plants and fluxes (soil-plant-atmosphere continuum, aboveground and belowground feedback) 
• Water use efficiency (WUE; value of WUE, stomatal control of WUE, C3 vs. C4 plants) 
• Advanced methodologies in soil-plant interactions. 
• Plant response to atmospheric and soil droughts; Open questions and introduction to seminar topics. 
• Seminars and discussions of seminal research papers related to the lecture topics.

 

Pflanzenphysiologisches Praktikum [WZ8059] oder Einführungspraktikum [WZ0334]

Lecturer: Dr. Mohanned Abdalla, Dr. Nicolai Koebernick, Dr. Alexander Christmann, Prof. Dr. Mutez Ahmed

Im Praktikum werden zunächst die Themen Photosynthese, Wasserhaushalt und Hormonphysiologie der Pflanzen in klassischen Versuchsanordnungen bearbeitet. Die Teilnehmer sollen anschließend einen Einblick in moderne Methoden der Pflanzenphysiologie erhalten. Sie werden dazu in einem weiterführenden Versuche Reportergenkonstrukte im Protoplastensystem von Arabidopsis transient exprimieren. Die Teilnehmer vertiefen ihre theoretischen Kenntnisse zu wichtigen Themen der Pflanzenphysiologie und lernen moderne Ansätze und Methoden der Pflanzenphysiologie kennen. Sie sind dann in der Lage, das erworbene Wissen auf vertiefte Fragestellungen anzuwenden. Sie erlernen grundlegende Arbeitstechniken der Pflanzenphysiologie und vermögen diese Methoden kompetent anzuwenden.

 

Research Project Advances on Root-Soil Interactions (Summer and Winter)

Lecturer: Prof. Dr. Mutez Ahmed, Dr. Mohanned Abdalla, Dr. Nicolai Koebernick, Dr. Tina Koehler, M.Sc. Henri Braunmiller

After successful completion of the module, students acquire in-depth theoretical knowledge and an expanded understanding of issues and modern working techniques in root-soil interactions. The participants are then able to apply the acquired knowledge to in-depth questions, to competently use modern working techniques of biophysical plant physiology, and to work with different crops and model plants, such as Arabidopsis. Additionally, the students will learn to design experiments in the lab or greenhouse/field. They gain experience in planning and conducting the experiments, organizing the work and analyzing experimental data. They are also able to scientifically analyze, interpret, discuss and present their obtained results in the context of current literature.

The practical course introduces participants to current topics and methods in physiological root-soil interactions. The practical course is offered for different topics. Topics include Soil-Plant-Environment Interactions, root phenotyping, plant stress physiology, root biology, rhizosphere biophysics and biogeochemistry as well as AI and advanced imaging techniques. The topic is determined by the ongoing projects and experiments and discussed with potential students. Examples of current topics: 
Plant water use regulation: advanced methodology to identify plant traits that allow plants to mitigate the adverse effects of harsh environmental conditions. 
Techniques: direct measurements of leaf water status, stomatal conductance, transpiration rate, root water uptake, root-soil hydraulic conductance and carbon assimilation rate will be conducted. Complementary root scanning and analysis (using Rhizovision/WinRhizo software) can be performed. 
Root exudates: Root mucilage and its physical properties are investigated at the chair, especially surface tension, viscosity and changing soil-water contact angle. 
Root-fungi interaction: Investigation of effects of Arbuscular mycorrhizal fungi (AMF) on root-soil contact and soil-plant hydraulics 
Techniques: root colonization assessment, using microscopic and molecular approaches, direct measurements of leaf water status, stomatal conductance, transpiration rate and carbon assimilation rate will be conducted on the mutants and the corresponding wild types of each crop. 
Root AI analysis: In recent years, root researchers are increasingly using X-ray micro-computed tomography (µCT) to visualize roots in 3D directly in their natural environment. At the chair, we aim to improve the segmentation and classification of roots using data driven AI approaches. Technique: We are developing a data driven tool to improve and simplify the analysis of µCT images of roots in soil.

 

Basic Practical Course on the Physics of Water Flow in Soils and Plants

Lecturer: Dr. Tina Köhler

This module equips students with the skills and knowledge required to measure water dynamics across the soil-plant-atmosphere continuum and the processes impacting it in the field. Upon successful completion of this module, students will have the following skills: 
1. To measure the fundamental physical properties of soils in the field, including type, texture, and structures to understand how those factors affect soil water dynamics (drying and wetting). 
2. To measure and monitor soil water dynamics (water potential and water content) throughout the growing season in the field to understand how it responds to water input (precipitation) and water depletion (evapotranspiration). 
3. To measure and monitor indicators of plant water status (transpiration, stomatal conductance, leaf xylem water potential) throughout the growing season in the field to understand how it is affected by atmospheric water demand and soil water availability. 
4. To measure plant architectural properties (leaf area, root length density) to understand how they contribute to plant water demand and supply.