Plant Cell Biology and Morphodynamics

Imaging approaches are central to our comprehension of the organization and interaction of molecules in biological systems. The infrastructure group led by Dr. Arun Sampathkumar provides research groups at the MPI-MP with access to a technology platform containing light and electron microscopes, as well as scientific and technical assistance to meet their cell biological needs. The group also undertakes research that focuses on understanding how the structural components of the cell (cell wall and the cytoskeleton) influence growth rates and directions in plants.

Understanding design principles behind plant morphogenesis

How life forms attain their specific shapes and modify their growth patterns in response to environmental and chemical signals has been the subject of numerous studies. The group’s research program investigates aspects of cell wall deposition and remodelling, factors that act as major determinants of plant growth. More specifically, the group aims to discern what processes regulate when and where a particular cell wall polymer is synthesised and deposited, what are the molecular players involved in such an activity, and how this affects growth and form of cells and tissues.

Current research questions in the group are highly interconnected:

How do mechanical forces orchestrate morphogenesis at cellular and tissue scales?
What are the molecular factors involved in transduction of mechanical signal to the cytoskeleton?
How do cell wall and cytoskeleton status affect cellular growth rates and directions?
How does mechanical feedback between cells influence gene expression and morphogenesis?

Cellulose synthase complex – microtubule interaction in pavement cells

Microtubules cytoskeleton (magenta) templates the deposition of stiff cellulose microfibrils by guiding cellulose synthase complexes (green) influencing cell shape

Floral Morphogenesis

Movie showing the sequence of shape changes that takes place during early stages of flower development

The group addresses these questions using an approach termed “Morphodynamics”. This relates to the extraction of quantitative data on spatio-temporal changes in gene expression patterns and protein dynamics using advancing imaging techniques as cells grow and divide. This, in combination with molecular and physical perturbations, allows for testing and developing hypotheses on the importance of cell wall and cytoskeleton during morphogenesis, an area of both fundamental and practical importance.

Services

The microscopy service unit offers:

Initial instruction and support for users of stereo-microscopes, light microscopes, confocal microscopes, electron microscopes (TEM, SEM), microtomes, and provision of protocols for their use, including equipment set-up and technical controls;
Advanced methods and protocols for sample preparation for light (fixation, embedding, sectioning, staining, visualisation and analysis of biological specimens) and electron microscopy (fixation, embedding, ultrathin sectioning, visualisation, and analysis of biological specimens);
Basics in software programmes „LAS, “Cell^P”, “LAS AF“, “MetaMorph” and image analysis;
Organisation of demonstrations of new microscopy techniques, and the introduction of new methods and newly developed techniques in microscopy and soft imaging systems;
Teaching and organising of courses on microscopy techniques and software programmes: a) Microscopy and Analysis, Imaging microscopy; b) Light, Electron and Scanning probe microscopy; c) Correlative microscopy: from Dynamics to Structure (integrated Laser and transmission electron microscopy)