Acetosyringone is a phenolic compound secreted by plant wounded tissues and is a specific agonist of the VirA/VirG two-component system[1]. Acetosyringone induces the activation of the VirA gene in Agrobacterium tumefaciens, triggering the autophosphorylation of VirA and the subsequent transfer of the phosphate group to the response regulator VirG. The phosphorylated VirG then activates the expression of all virulence (vir) genes on the Ti plasmid, thereby driving the processing, transfer, and stable integration of T-DNA into the plant genome[2]. Acetosyringone is widely used in Agrobacterium-mediated genetic transformation and plant antibacterial mechanism studies[3][4].
Pre-induction of Agrobacterium strains harboring pMDC45 with Acetosyringone (100μM; 24h) and 10mM D-glucose in TAP medium significantly enhanced the integration efficiency of GFP and HPT transgenes in Dunaliella salina during in vivo co-cultivation[5]. Incubation of G. intraradices spores with Acetosyringone (200μM, 2h) resulted in an overall increase in hyphal respiration and significantly induced the rapid expression of symbiotic related genes such as GiBP1[6].
Co-incubating Agrobacterium with 500μM acetosyringone for 2–4h, infiltrating the mixture into Nicotiana benthamiana leaves and sampling at 4 dpi increased transient GUS expression about five-fold[7].
References:
[1] Xi J, Patel M, Dong S, Que Q, Qu R. Acetosyringone treatment duration affects large T-DNA molecule transfer to rice callus. BMC Biotechnol. 2018;18(1):48.
[2] Shaw CH. Swimming against the tide: chemotaxis in Agrobacterium. Bioessays. 1991;13(1):25-29.
[3] Sheikholeslam SN, Weeks DP. Acetosyringone promotes high efficiency transformation of Arabidopsis thaliana explants by Agrobacterium tumefaciens. Plant Mol Biol. 1987;8(4):291-298.
[4] Szatmári Á, Móricz ÁM, Schwarczinger I, et al. A pattern-triggered immunity-related phenolic, acetosyringone, boosts rapid inhibition of a diverse set of plant pathogenic bacteria. BMC Plant Biol. 2021;21(1):153.
[5] Srinivasan R, Gothandam KM. Synergistic Action of D-Glucose and Acetosyringone on Agrobacterium Strains for Efficient Dunaliella Transformation. PLoS One. 2016;11(6):e0158322.
[6] Flores-Gómez E, Gómez-Silva L, Ruiz-Medrano R, Xoconostle-Cázeres B. Role of acetosyringone in the accumulation of a set of RNAs in the arbuscular mycorrhiza fungus Glomus intraradices. Int Microbiol. 2008;11(4):275-282.
[7] Norkunas K, Harding R, Dale J, Dugdale B. Improving agroinfiltration-based transient gene expression in Nicotiana benthamiana. Plant Methods. 2018;14:71.