A fungal phospholipase C involved in the degradation of plant glycosylinositol phosphorylceramides during Arabidopsis/Botrytis interaction

This study investigates the presence and significance of phosphorylated oligosaccharides that accumulate during the interaction between Arabidopsis thaliana and Botrytis cinerea, a necrotrophic fungus that poses a major threat to crops worldwide. While previous research has extensively characterized cell wall-derived molecules during fungal infection, the role of plasma membrane-derived ones remains unclear. Here, we reveal the discovery of inositol phosphate glycans (IPGs) released during infection, originating from plant sphingolipids, specifically glycosylinositol phosphorylceramides (GIPC). Advanced chromatography, mass spectrometry techniques and molecular biology were employed to identify these IPGs, and determine their origins. In addition to the well-characterized role of B. cinerea in releasing cell wall-degrading enzymes, this research suggests that B. cinerea's enzymatic machinery may also target the degradation of the plant plasma membrane. As a consequence of this, IPGs identical to those generated by the host plant are released, most likely due to activity of a putative phospholipase C that acts on GIPC plasma membrane lipids. These insights could pave the way for developing new strategies to enhance crop resistance by focusing on membrane integrity in addition to cell wall fortification.