0000000000255170
AUTHOR
Jean-luc Cacas
Are diacylglycerol-kinases involved in cryptogein-induced early signaling events?
SPE IPM; National audience
Out for a Walk Along the Secretory Pathway During Programmed Cell Death
This chapter provides a comprehensive updated analysis on the role of the secretory pathway in the orchestration of cell’s demise, an emerging and promising research topic in the field of plant programmed cell death (PCD). Since my first review on this topic, a plethora of data has been published supporting the concept that endomembrane system-forming subcellular compartments cooperate to coordinate cellular responses to developmental and environmental cues and thereby can dictate a cell’s ultimate fate. Thus, the early secretory pathway, encompassing the endoplasmic reticulum and Golgi apparatus, can be involved in the perception of extrinsic and intrinsic stimuli. It can also be an active…
Mechanisms of Defence to Pathogens : Biochemistry and Physiology
SPE IPM; International audience; Plant defences comprise both pre-existing barriers as well as defences induced upon perception of pathogen-associated molecular patterns (PAMPs) or microbe-associated molecular patterns (MAMPs) or molecules produced from damage as a result of infection (damage-associated molecular patterns (DAMPs)). This chapter focuses on the induced mechanisms of defence. The inducibility of phytoalexin biosynthesis has probably been favoured in the course of evolution by biological constraints such as metabolic costs and functional side-effects associated with chemical defence. Historically, the term ‘hypersensitive’ refers to the rapid and localized cell death induced in…
GIPC: Glycosyl Inositol Phospho Ceramides, the major sphingolipids on earth
What are the most abundant sphingolipids on earth? The answer is Glycosyl Inositol Phosphoryl Ceramides (GIPCs) present in fungi and the green lineage. In this review, we discuss the putative role of plant GIPCs in the lipid bilayer asymmetry, in the lateral organization of membrane rafts and in the very long chain fatty acid inter-leaflet coupling of lipids in the plant plasma membrane (PM). A special focus on the structural similarities -and putative functions- of GIPCs is discussed by comparison with animal gangliosides, structural homologs of plant GIPCs.
The combined action of 9 lipoxygenase and galactolipase is sufficient to bring about programmed cell death during tobacco hypersensitive response
International audience; Oxylipins, derived from fatty acid hydroperoxides (FAHs), are thought to play different roles during plant pathogen interactions. During hypersensitive response (HR) some of them serve as signals necessary for defence gene activation whereas others could contribute to pathogen killing or could participate in the execution of plant programmed cell death (PCD) associated with this resistance. In order to address the role of these compounds in the latter process, we have closely observed lipid peroxidation, the first step of this metabolic pathway, under different situations which led either to accelerated or inhibited HR cell death. The oxidative process has been studi…
Revisiting Plant Plasma Membrane Lipids in Tobacco: A Focus on Sphingolipids
International audience; The lipid composition of plasma membrane (PM) and the corresponding detergent-insoluble membrane (DIM) fraction were analyzed with a specific focus on highly polar sphingolipids, so-called glycosyl inositol phosphorylceramides (GIPCs). Using tobacco (Nicotiana tabacum) 'Bright Yellow 2' cell suspension and leaves, evidence is provided that GIPCs represent up to 40 mol % of the PM lipids. Comparative analysis of DIMs with the PM showed an enrichment of 2-hydroxylated very-long-chain fatty acid-containing GIPCs and polyglycosylated GIPCs in the DIMs. Purified antibodies raised against these GIPCs were further used for immunogold-electron microscopy strategy, revealing …