Molecular mechanisms in developmental boundary formation
In the Arabidopsis thaliana root, stem cells divide in the apical stem cell niche of the meristem and originate daughter cells that divide until they reach a distal boundary denominated transition zone (TZ) where they start differentiating. The balance between cell division and cell differentiation is regulated by two antagonistic hormones - auxin that promotes cell division and cytokinin that promotes cell differentiation ¿ which interact with each other through an elegantly simple regulatory circuit.
Aim of this project is to understand how changes in auxin level mediated by cytokinin via this regulatory circuit control the position of the TZ developmental boundary thus determining meristem size, and how environmental stimuli are integrated in this circuit in affecting root growth.
This will be achieved through a combination of state of the art genetic, molecular and cell biology approaches including single and multiple mutants, cell-specific gene expression, fluorescence-activated cell sorting (FACS) coupled to expression profiling and tissue¿specific microarray analysis.