A culture filtrate of Phytophthora infestans primes defense reaction in potato cell suspensions.

Priming of defense reactions by an elicitor results in an enhanced ability of the plant to respond to subsequent pathogen challenges. We previously showed that application of lipopolysaccharides (LPS) to potato cell suspensions causes apoplastic acidification, but does not stimulate lipoxygenase (LOX) activity. Here, we tested the ability of various elicitors to prime and elicit defense reactions in potato cell suspensions.

Activation of defence reactions in Solanaceae: where is the specificity?

When a potential pathogen attempts to infect a plant, biochemical and molecular communication takes place and leads to the induction of plant defence mechanisms. In the case of efficient defence, visible symptoms are restricted and the pathogen does not multiply (incompatible interaction); when defence is inefficient, the plant becomes rapidly infected (compatible interaction). During the last 30 years, a growing body of knowledge on plant-pathogen interactions has been gathered, and a large number of studies investigate the induction of various plant defence reactions by pathogens or by pathogen-derived compounds.

Lipopolysaccharides of Pectobacterium atrosepticum and Pseudomonas corrugata induce different defence response patterns in tobacco, tomato, and potato.

Lipopolysaccharides (LPS), ubiquitous cell surface components of Gram-negative bacteria, are directly implicated in plant/pathogen interactions. However, their perception by the plant, the subsequent signal transduction in both compatible and incompatible interactions, as well as the defence reactions induced in compatible interactions are as yet poorly understood. We focused on biochemical and physiological reactions induced in cell suspensions of three Solanaceae species (tobacco, tomato, and potato) by purified lipopolysaccharides from PECTOBACTERIUM ATROSEPTICUM (PA), a pathogen of potato, and PSEUDOMONAS CORRUGATA (PSC), a pathogen of tomato.