TY - JOUR T1 - Alkyl gallates display elicitor activities in tobacco plants JF - bioRxiv DO - 10.1101/145425 SP - 145425 AU - Pascale Goupil AU - Razik Benouaret AU - Claire Richard Y1 - 2017/01/01 UR - http://biorxiv.org/content/early/2017/06/02/145425.abstract N2 - Alkyl gallates showed elicitor activities on tobacco in both whole plants and cell suspensions. Methyl gallate (MG), ethyl gallate (EG) and n-propyl gallate (PG) infiltration into tobacco leaves induced hypersensitive reaction-like lesions and topical production of autofluorescent compounds revealed under UV light. When sprayed on tobacco plants at 5 mM, EG promoted upregulation of defence-related genes such as the antimicrobial PR1, β-1,3-glucanase PR2, chitinase PR3 and osmotin PR5 target genes. Tobacco BY-2 cells challenged with EG underwent cell death in 48 h, significantly reduced in the presence of the protease inhibitor aprotinin. The three alkyl gallates all caused alkalinisation of the BY-2 extracellular medium, whereas gallic acid did not trigger any pH variation. Using EGTA or LaCl3, we showed that Ca2+ mobilisation occurred in BY-2 cells elicited with EG. Overall, our findings are the first evidence of alkyl gallate elicitor properties with early perception events on plasma membrane, potential hypersensitive reactions and PR-related downstream defence responses in tobacco.Highlights– Alkyl gallates elicited defence reactions in tobacco– Alkyl gallates induced local biochemical changes in tobacco leaves– Alkyl gallates caused modification of plasma membrane properties– Ethyl gallate led to defence transcript accumulation and dose-dependent cell death associated with hypersensitive response– Alkyl gallates are novel elicitor agents well-suited to crop protection schemes. ER -