Fig. 3.

OGs released upon A. thaliana–B. cinerea interaction. (A) Proportion of pectin lyase products among total OG produced after 20-h infection of A. thaliana leaves by B. cinerea. Data are means ± SD; n = 3. (B and C) Characterization of OGs produced after 20-h infection by HP-SEC-MS. (B) PNL products; (C) PG products. Data are means ± SD; n = 3. (D) MS² fragmentation pattern of oxydized GalA₂ oligomer (m/z 385.0683) eluting at 7.8 min in Fig. 1A using HP-SEC with online MS. (E) Kinetics of GalA₃, GalA₂, and oxydized GalA₂ upon infection. Data are means ± SD; n = 3. (F) DP10 to -15 OGs degradation by B. cinerea. OGs (2 mg/mL) were mixed with germinated B. cinerea spores and the reaction immediately stopped by addition of a volume of ethanol before analysis by HP-SEC-MS. (G) Composition of semipurified OGs from leaves infected by WT B. cinerea strain. (H) GUS quantification and staining of A. thaliana leaves expressing the promoter PGIP1::GUS fusion after the infiltration of GalA₃ (200 µM) and semipurified OGs containing 5 µM of GalA₄MeAc-H₂O. (I) GUS quantification and staining of A. thaliana dark-grown hypocotyls expressing the promoter PGIP1::GUS fusion after the infiltration of GalA₃ and semipurified OGs from leaves infected by WT B. cinerea strain. OGs are named GalA_xMe_yAc_z. Subscript numbers indicate the degree of polymerization and the number of methyl- and acetylester groups, respectively. Asterisks directly above bars denote statistical significance compared with mock treatment (*P < 0.05).