title: The Arabidopsis patatin-like protein 2 (PLP2) plays an essential role in cell death execution and differentially affects biosynthesis of oxylipins and resistance to pathogens.
abstract: We previously reported that patatin-like protein 2 (PLP2), a pathogen-induced patatin-like lipid acyl hydrolase, promotes cell death and negatively affects Arabidopsis resistance to the fungus Botrytis cinerea and to the bacteria Pseudomonas syringae. We show here that, on the contrary, PLP2 contributes to resistance to Cucumber mosaic virus, an obligate parasite inducing the hypersensitive response. These contrasted impacts on different pathosystems were also reflected by differential effects on defense gene induction. To examine a possible link between PLP2 lipolytic activity and oxylipin metabolism, gene expression profiling was performed and identified B. cinerea among these pathogens as the strongest inducer of most oxylipin biosynthetic genes. Quantitative oxylipin profiling in wild-type and PLP2-modified, Botrytis-challenged plants established the massive accumulation of oxidized fatty acid derivatives in infected leaves. Several compounds previously described as modulating plant tissue damage and issued from the alpha-dioxygenase pathway were found to accumulate in a PLP2-dependent manner. Finally, the contribution of PLP2 to genetically controlled cell death was evaluated using PLP2-silenced or -overexpressing plants crossed with the lesion mimic mutant vascular-associated death 1 (vad1). Phenotypic analysis of double-mutant progeny showed that PLP2 expression strongly promotes necrotic symptoms in vad1 leaves. Collectively, our data indicate that PLP2 is an integral component of the plant cell death execution machinery, possibly providing fatty acid precursors for the biosynthesis of specific oxylipins and differentially affecting resistance to pathogens with distinct lifestyles.
authors.affiliation: Institut de Biologie Moléculaire des Plantes du CNRS, UPR, conventionné avec l'Université Louis Pasteur, Strasbourg, France.
authors.forename: Sylvain
authors.initials: S
authors.lastname: La Camera
authors.forename: Claudine
authors.initials: C
authors.lastname: Balagué
authors.forename: Cornelia
authors.initials: C
authors.lastname: Göbel
authors.forename: Pierrette
authors.initials: P
authors.lastname: Geoffroy
authors.forename: Michel
authors.initials: M
authors.lastname: Legrand
authors.forename: Ivo
authors.initials: I
authors.lastname: Feussner
authors.forename: Dominique
authors.initials: D
authors.lastname: Roby
authors.forename: Thierry
authors.initials: T
authors.lastname: Heitz
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism* / Q000382:microbiology / Q000821:virology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D020171:Botrytis / Q000472:pathogenicity; D016923:Cell Death; D017799:Cucumovirus / Q000472:pathogenicity; D020869:Gene Expression Profiling; D006867:Hydrolases / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D054883:Oxylipins / Q000378:metabolism*; D000217:Acyltransferases; D010740:Phospholipases
chemical_list: D029681:Arabidopsis Proteins; D006867:Hydrolases; D054883:Oxylipins; C507690:At2g26560 protein, Arabidopsis; D000217:Acyltransferases; D010740:Phospholipases