PO-27: Sunflower WRINKILED1 transcription factor regulates through an Aw box binding sequence with a particular base bias

In sunflower, the biochemical pathways leading to oil synthesis and accumulation seeds hare been largely stud how these pathways are regulated is less well understood. WRLE KLED1 (WRII) factor, a member of the AP2/ER,EBP class, is considered a kep regulator in the control of carbon allocation between the glycolytic and fatty acid biosynthetic pathways' The AW box (CNTNG(N)7CG) is characterized as an ,4¿WR.I1 ninaing element nith a location-sensitive feature in Arabidopsis. In this work, we identified the sunflowe r WRI1 gen and characterized its activity in electrophoretic mobility shift assays (EMSA). We studied its role as a co-regulator of sunflower genes involved,in plastidial fatty acid synthesis, identifying tbc gene isoforms that are recognized and bound Uy ttre transcription factor. We also determired the base bias at the N positions in the active sunflower AWbox motif. The sunflower AWbox b sequence-sensitive at the nolt-conserved positions, enabling WRll-binding. Moreover, sunflosu WR'I1 could bind to a non-canonical AW-box motif, opening the possibility of searchi¡g fbr ner target genes.