Vir gene inducers in Dunaliella salina; an insight in to the Agrobacterium-mediated genetic transformation of microalgae

Phenolic compounds such as vanillin, vanillic acid, gallic acid, coumarin, caffeic acid and acetosyringone, extracted and identified from spent medium of Dunaliella salina has shown to facilitate the virulence (vir) gene induction in Agrobacterium strain A348 (harboring pSM358, a virE::LacZ fusion vector). Among these phenolic compounds, vanillin showed highest concentration of 38.12 ± 0.88 μg L− 1 in spent medium. All these phenolic compounds were evaluated independently for induction of vir gene expression using β-galactosidase activity. Our results showed that except for gallic acid, there was significant vir gene induction activity and these phenolic compounds may be involved in facilitating efficient Agrobacterium-mediated transformation in D. salina.