It is concluded that local climatic conditions greatly influenced the evolution of population earliness, thus being a major factor of differentiation in the DM system. Accordingly, a substantial proportion (approximately 25 %) of genetic variance was distributed among populations, suggesting that diversity was on average conserved during evolution but was differently distributed by natural selection (and possibly drift). Earliness is a complex trait and each genetic factor is controlled by multiple homeoalleles; the next step will be to look for spatial divergence in allele frequencies.

The presence of acrylamide (AA), a potentially carcinogenic and neurotoxic compound, in food has become a major concern for public health. AA in plant-derived food mainly arises from the reaction of the amino acid asparagine (Asn) and reducing sugars during processing of foodstuffs at high temperature. Using a selection of genotypes from the chicory (Cichorium intybus L.) germplasm, we performed Asn measurements in storage roots and leaves to identify genotypes contrasting for Asn accumulation. We combined molecular analysis and grafting experiments to show that leaf to root translocation controls Asn biosynthesis and accumulation in chicory storage roots. We could demonstrate that Asn accumulation in storage roots depends on Asn biosynthesis and transport from the leaf, and that a negative feedback loop by Asn on CiASN1 expression impacts Asn biosynthesis in leaves. Our results provide a new model for Asn biosynthesis in root crop species and highlight the importance of characterizing and manipulating Asn transport to reduce AA content in processed plant-based foodstuffs.

1 0 3 1 • Using a selection of genotypes from the chicory germplasm we performed Asn 3 2 measurements in storage roots and leaves to identify genotypes contrasting for Asn 3 3 accumulation. We combined molecular analysis and grafting experiments to show that 3 4 leaf to root translocation controls asparagine biosynthesis and accumulation in chicory 3 5 storage roots. 3 6• We could demonstrate that Asn accumulation in storage roots depends on Asn 3 7 biosynthesis and transport from the leaf, and that a negative feedback loop by Asn on 3 8CiASN1 expression impacts Asn biosynthesis in leaves. 3 9 • Our results provide a new model for asparagine biosynthesis in root crop species and 4 0 highlight the importance of characterizing and manipulating asparagine transport to 4 1 reduce AA content in processed plant-based foodstuffs.4 2