Prof. Alexis MaizelCell and Developmental biology
How does the genetic information encoded in the DNA reliably lead to a specific organismal shape? The laboratory is interested in understanding morphogenesis in plants, which, unlike animals, form organs throughout their life. We study the formation of lateral roots that determine the plant's capacity to forage its environment for nutrients and stabilize its anchoring. To understand how these new roots are formed, we combine molecular genetics with cell biology, imaging and quantitative analysis.
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TOR acts as a metabolic gatekeeper for auxin-dependent lateral root initiation in Arabidopsis thaliana 
We primarily use Arabidopsis thaliana, a model plant which forms lateral roots from founder cells located deep in the primary root. The process starts with the de novo formation of stem cells, the asymmetric expansion of two abutting founder cells in the pericycle.
These founder cells share a common interface and expand along it, prefiguring the future dome-shaped lateral root primordium that grows out of the parental root. Accompanying the asymmetric growth, both nuclei migrate toward the common cell wall, and the cells divide asymmetrically. Failure to execute these steps leads to an aberrantly shaped lateral root or the complete arrest of lateral root growth.
Lateral root formation is a self-organizing process during which the founder cells invariably undergo first an asymmetric anticlinal division. We showed that radial expansion of the founder cells and spatial accommodation by the overlying endodermis is essential for forming a lateral root and the first asymmetric cell divisions. We have made key discoveries about the role of the cell wall and the cytoskeleton in this process. We also have co-developed innovative methods to analyse the shape of cells.
The laboratory combines precise manipulation of cell properties at the cell and tissue scale with live imaging and quantitative analysis to understand the mechanisms responsible for the proper execution of the lateral root initiation program. We have developed several techniques to study and analyze the morphogenesis of lateral roots in real-time.
Our current and future research concentrate on understanding how cell polarity, growth and division articulate to specify distinct identities in the developing lateral root.
Plants harvest energy from sunlight in their leaves to produce sugar. To support their growth, they must also forage for water and mineral nutrients with their roots. Designing better roots represents an under-explored way to increase yield in changing environmental and climate conditions, reduce fertilizer use and pollution, promote soil health and, ultimately, help people.
How to optimize root systems? This is not an easy question. Building more roots in an uncontrolled manner comes with construction and maintenance costs. Optimizing root systems, therefore, requires a basic understanding of the cellular mechanisms that control how and where new roots are formed.
By unravelling the basic concepts and mechanisms underpinning the formation of roots, our work will pave the way for the rational design of better crop root systems.
The Maizel lab started as an independent group in the CellNetworks Cluster of Excellence. The laboratory is part of the collaborative research centre SFB1101 on specificity in plant processes, the FOR2581 on plant Morphodynamics and the HBIGS graduate school. Funds from a variety of public sources support our work.
In the context of the Bertalanffy live podcast, Michael Stitz and Alexis Maizel discuss their research with roots, their career, the challenges of managing work and family and how small changes can have a large impact. In german.