FIGURE 1.

Impact of bacterial supernatants of PGC‐producing Pseudomonas on the germination rate of different broomrapes. (A) Biosynthetic pathway of the DAPG in Pseudomonas cells (according to Biessy & Filion, 2021). The genes involved in the different transformation steps are written in italic. (B) Quantification of Phloroglucinol (PG), monoacetylphloroglucinol (MAPG), diacetylphloroglucinol (DAPG) and triacetylphloroglucinol (TAPG) in the bacterial supernatants of Pseudomonas ogarae F113 and its mutant derivatives: ΔphlD (mutant impaired in the production of DAPG); ΔphlD Comp. (complemented mutant strain overproducing PG) and Over phlD (DAPG, MAPG and PG overproducing strain). Error bars correspond to the standard deviation; ND: Not detected. (C) Impact of these supernatants on the germination capacity of different P. ramosa pathovars and O. cumana in vitro. The supernatants as well as the control condition were supplemented with 1 μM of the germination stimulant (GR24). Results are expressed as percentage of germination of the non‐inoculated ABm medium control. Statistical differences were assessed by ANOVA and Kruskal‐Wallis test using a Bonferroni correction and are indicated with letters. The horizontal lines indicate the interquartile range with the centre representing the median.