Xyloglucans fucosylation defects do not alter plant boundary domain definition.

The CUP-SHAPED COTYLEDON (CUC) transcription factors play a fundamental role in plant morphogenesis by defining boundary domains throughout plant development. Despite their central roles in plant development, little is known about the CUC molecular network. In a recent work, we identified a role for MUR1, a protein involved in the production of GDP-L-Fucose, in this network and showed that fucose per se is required for proper boundary definition in various developmental contexts. Which pathway involving fucose is required to determine boundary is not yet known. Here, we use a previously described mutant and transgenic line with reduced fucosylated xyloglucans (XyG) to explore one such pathway. By quantitatively comparing leaf shape, we show that defects in XyG fucosylation do not impact leaf serrations development suggesting that fucose absence in XyG does not impact boundary development in mur1-1 mutant. Thus another - not yet identified - pathway or fucosylated compound contribute to boundary domain definition.