Leaf development and morphogenesis

Leaves are a powerful system to understand how organs acquire their shape. We study the genetic and hormonal control of leaf margin dissection, boundary formation and leaflet individualisation, with a focus on the NAM/CUC transcription factors, miR164 and auxin. We showed that the balance between MIR164A and CUC2 controls leaf margin serration, that miR164, CUC genes and LATERAL SUPPRESSOR interact to control axillary meristem formation, and that NAM/CUC boundary genes promote leaflet formation in distantly related eudicots.

Related publications

• Nikovics et al., 2006 — The balance between the MIR164A and CUC2 genes controls leaf margin serration in Arabidopsis
• Raman et al., 2008 — Interplay of miR164, CUP-SHAPED COTYLEDON genes and LATERAL SUPPRESSOR controls axillary meristem formation in Arabidopsis thaliana
• Blein et al., 2008 — A conserved molecular framework for compound leaf development

These findings led us to propose that leaf dissection relies on the interplay between boundary domains, KNOX gene activity and auxin gradients. We further reviewed the genetic and molecular networks controlling leaf polarity and the comparison between simple and compound leaves, and analysed the evolution and specific roles of CUC1–CUC3 during Arabidopsis leaf serration.

Related publications

• Blein et al., 2010 — Leaf development: what it needs to be complex
• Blein, 2009 — A conserved mechanism at the base of leaf dissection
• Hasson et al., 2010 — Leaving the meristem behind: the genetic and molecular control of leaf patterning and morphogenesis
• Hasson et al., 2011 — Evolution and diverse roles of the CUP-SHAPED COTYLEDON genes in Arabidopsis leaf development

More recently, we combined genetics and morphometrics to show that mutations in different pathways can act synergistically to alter leaf dissection, and that GDP-L-fucose is required for boundary definition and differential growth at the leaf margin. Together, this work connects molecular boundary formation to the evolution and diversification of leaf shape.

Related publications

• Blein et al., 2013 — Combinations of Mutations Sufficient to Alter Arabidopsis Leaf Dissection
• Gonçalves et al., 2017 — GDP-L-fucose is required for boundary definition in plants