Ricerc@Sapienza

A clear example of interspecific variation is the number of root cortical layers in plants. The genetic
mechanisms underlying this variability are poorly understood, partly due to the lack of a convenient
model. Here, we demonstrate that Cardamine hirsuta, unlike Arabidopsis thaliana, has two cortical
layers that are patterned during late embryogenesis. We show that a miR165/6-dependent
distribution of the HOMEODOMAIN LEUCINE ZIPPER III (HD-ZIPIII) transcription factor

How do genes modify cellular growth to create morphological diversity? We study this problem in two related plants with differently shaped leaves: Arabidopsis thaliana (simple leaf shape) and Cardamine hirsuta (complex shape with leaflets). We use live imaging, modeling, and genetics to deconstruct these organ-level differences into their cell-level constituents: growth amount, direction, and differentiation.