Investigating the cellular basis of organ symmetry establishment in plants

MOUBAYIDIN_J22DTP

During multicellular organ development, the establishment of a symmetric pattern, e.g., radial and bilateral symmetry, requires careful coordination of cells dividing and expanding within tissues. This developmental challenge is genetically committed and impacts on organ function.

Plants, which produce new organs post-embryonically such as roots, leaves and flowers, show a huge variety of ‘geometric’ (symmetric) shapes at the organ level, ranking from flat sheets with a left and right side (bilateral symmetry), to round and pea-like (radial symmetry). Despite its importance, our knowledge about symmetry foundation during organ development is very limited. Therefore, the aim of this project is to elucidate the cellular basis underpinning symmetry foundation, using Arabidopsis thaliana as a model system.

To this end, the student will investigate the growth dynamics of wild-type gynoecium – the female reproductive structure of the flower – and will employ quantitative microscopy techniques, genetic and molecular experiments, to understand how cell-division and cell-expansion are coordinated during radial symmetry establishment. These experiments will be carried out alongside the analysis of a key loss-of-function mutant, to inform the cellular behaviours which break radial symmetry and promote a bilaterally symmetric pattern instead. Moreover, the project aims at elucidating a general, conserved mechanism(s) employed across plant organs to set up their symmetric patterns, thus, the student will investigate how specific cellular activities (such as cell proliferation and elongation) impact on root radial symmetry when driven under the control of tissue-specific promoters. Thus, overall, this project will shed light on the biological principles necessary to set up a ground symmetric type during organogenesis.

The research programme will provide the student with the opportunity to develop the skills and expertise to work at the cutting edge of biological science, in a highly stimulating environment. Moreover, they will be inducted into the existing JIC postgraduate training and mentoring programme, and benefit from attending relevant national and international conferences and outreach events to communicate their results and networking within the wider academic community.

References
1) Coordination of biradial-to-radial symmetry and tissue polarity by HD-ZIP II proteins. Carabelli M, Turchi L, Morelli G, Østergaard L, Ruberti I, Moubayidin L. Nat Commun. 2021 Jul 14;12(1):4321.

2) Gynoecium formation: an intimate and complicated relationship. Moubayidin L and Østergaard L. Curr Opin Genet Dev. 2017 Aug;45:15-21.

3) Dynamic control of auxin distribution imposes a bilateral-to-radial symmetry switch during gynoecium development. Moubayidin L, Ostergaard L. Curr Biol. 2014 Nov 17;24(22):2743-8.