Oligogalacturonide production upon Arabidopsis thaliana – Botrytis cinerea interaction

Abstract

Despite an ever-increasing interest for the use of pectin-derived oligogalacturonides (OGs) as biological control agents in agriculture, very little information exists—mainly for technical reasons—on the nature and activity of the OGs that accumulate during pathogen infection. Here we developed a sensitive OG profiling method, which revealed unsuspected features of the OGs generated during infection of Arabidopsis thaliana with the fungus Botrytis cinerea. Indeed, in contrast to previous reports, most OGs were acetyl- and methylesterified, and 80% of them were produced by fungal pectin lyases, not by polygalacturonases. Polygalacturonase products did not accumulate as larger size OGs but were converted into oxidized GalA dimers. Finally, the comparison of the OGs and transcriptomes of leaves infected with B. cinerea mutants with reduced pectinolytic activity but with decreased or increased virulence, respectively, identified candidate OG elicitors. In conclusion, OG analysis provides insights into the enzymatic arms race between plant and pathogen and facilitates the identification of defense elicitors.

The exogenous application of AtPGLR, an endo‐polygalacturonase, triggers pollen tube burst and repair

“…The mode of action of AtPGLR on more complex substrates, i.e. pectins of DM 30% was tested using a recently developed LC-MS/MS oligoprofiling method (Voxeur et al, 2019). The OGs produced by AtPGLR differed from those obtained after degradation of pectins with a commercial PG from A. aculeatus.…”

“…Two-hundred microliters of the upper phase was dried using a Speed Vac (2 h, 45°C) and resuspended in 200 µl of ultra-pure water. Chromatographic separation was performed on an ACQUITY UPLC Protein BEH size exclusion chromatography (SEC) column (125 A, 1.7 µm, 4.6 X 300 mm; Waters, https://www.waters.com/) according to Voxeur et al, (2019). Elution was performed in 50 mM ammonium formate, formic acid 0.1% at a flow rate of 0.4 ml min À1 and a column oven temperature of 40°C.…”

Arabinoxylan-Oligosaccharides Act as Damage Associated Molecular Patterns in Plants Regulating Disease Resistance

“…Confirming this hypothesis, pectic oligogalacturonides (OGs) were first cell wall DAMPs to be characterized (Nothnagel et al, 1983). OGs are derived from homogalacturonan, the main component of pectins, as a result of the activity of CWDE released by the pathogens during the colonization process (Ridley et al, 2001;Benedetti et al, 2015;Voxeur et al, 2019). Also, the overexpression or inactivation of genes encoding enzymes involved in the control of pectin structure [e.g., pectin methyl esterases (PME) and PME inhibitors], results in the modification of the degree of OGs release upon infection, and alterations of disease resistance phenotypes (Ferrari et al, 2008;Raiola et al, 2011;Lionetti et al, 2017;Benedetti et al, 2018;De Lorenzo et al, 2019).…”

ARABIDOPSIS DEHISCENCE ZONE POLYGALACTURONASE 1 (ADPG1) releases latent defense signals in stems with reduced lignin content

“…latent signal molecules sequestered within plant cell walls and characterization of their receptors. Improved approaches for the analysis of plant cell wall-released pectic fractions will facilitate these efforts (69). Understanding how plants remodel their cell walls as a result of engineered structural perturbations may allow us to better design improved lignocellulosic energy crops by optimizing bioprocessing quality, yield, and stress resistance.…”