A Synthetic Reaction-Diffusion System for Engineering Patterning and Self-Organisation in Plant Stem Cells
Reaction-diffusion systems are employed in biology to establish patterns associated with the formation of distinct tissues and organs at the multicellular scale.
In plants, reaction-diffusion systems in the shoot apical meristem (SAM) govern important processes including leaf initiation and stem cell maintenance.
We have recently identified a minimal three-component reaction diffusion system that controls meristem-organ boundary specification in the SAM, a critical process for the establishment of plant architecture. This comprises a positive feedback-loop between two transcriptional regulators, one of which is mobile, attenuated by localised induction of a microRNA inhibitor which targets the second transcriptional regulator for destruction. The gradient formed by the mobile transcriptional regulator causes differential accumulation of the other system components resulting in the establishment of discrete expression domains within the SAM.
We now seek to develop a synthetic self-organising regulatory network that can create analogous distinct expression domains within a field of cells such as the SAM or leaf epidermis. In this project, a derivative synthetic system will be re-engineered in Arabidopsis thaliana and Marchantia polymorpha, comprising synthetic orthogonal components to determine if such a minimal system is sufficient to recapitulate the establishment of discrete expression domains observed in nature.
The engineered system will be tested in vivo and refined to best mimic the expression domains created by the natural boundary specification system. Further modification could enable a broad spectrum of potential patterns to be created and employed in the design and re-engineering of plant architecture, an important area in synthetic biology and in achieving sustainable agriculture in the future.