Tween 20 inducible genes

Polyethylene glycol sorbitan monoacylates (Tween) are detergents of widespread use in plant sciences. We show them, notably Tween 20, to cause a rapid and complex change in transcript abundance which bears all characteristics of a PAMP / elicitor-induced defense response, and they do so at concentrations which cause no detectable deleterious effects on plant cellular integrity. The activity does not reside in the intact Tween molecule itself, but is caused by medium-chain fatty acids, notably lauric acid (LA), which are efficiently released from the Tween-backbone by the plant. The Tween / LA-response is independent of the jasmonate signalling system. Medium-chain fatty acids are thus novel elicitors/regulators of plant pathogen defense. The results also have several practical implications: (i) The use of Tweens and, as we show, several other detergents, as solvating/wetting agents on intact plants causes profound physiological changes which may mask actual effects of test compounds; (ii) Tweens by themselves can be regarded (and probably used) as economical, non-toxic, and safe-to-apply elicitors of inducible plant immunity against pathogens.

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