The SmFLS gene was cloned from eggplant and has an ORF of 1014 bp encoding 337 amino acids. The deduced protein sequence of SmFLS was 88.07% and 84.94% identical to homologs encoded by StFLS in Solanum tuberosum and SlFLS in S. lycopersicum, respectively. SmFLS contains typical DIOX_N and 2OG-Fe (II)_Oxy functional domains, as well as five strictly conserved amino acid residues (H223, D225, H279, R289, and S291) related to FLS enzyme activity. Phylogenetic tree analysis showed that SmFLS had the closest genetic relationship with the FLS genes in potato and tomato. At a high temperature of 35 °C, the expression level of SmFLS was higher than that of the control in the same period, and it reached extremely significant levels on 15DAF and 20DAF, at which the eggplant peel color became lighter accordingly. Upon overexpression of SmFLS in eggplant, the flavonol content of transformed plants was significantly higher than that of untransformed plants, and the peel color was lighter than that of the control. The results indicate that SmFLS negatively regulates eggplant peel coloration under high temperature.
Keywords: FLS; aubergine; coloration de la peau; eggplant; flavonol; high temperature; peel coloring; température élevée.