The Delay of Raphanus raphanistrum subsp. sativus (L.) Domin Seed Germination Induced by Coumarin Is Mediated by a Lower Ability to Sustain the Energetic Metabolism

Abstract

In the present study, the mode of action of coumarin using the germination process as a target was investigated. A dose–response curve, built using a range of concentrations from 0 to 800 µM, allowed us to identify a key concentration (400 µM) inhibiting the germination process, reducing its speed without compromising seed development. Successively, short time-course (0–48 h) experiments were carried out to evaluate the biochemical and metabolic processes involved in coumarin-induced germination delay. The results pointed out that coumarin delayed K+, Ca2+, and Mg2+ reabsorption, suggesting a late membrane reorganisation. Similarly, seed respiration was inhibited during the first 24 h but recovered after 48 h. Those results agreed with ATP levels, which followed the same trend. In addition, the untargeted metabolomic analysis allowed to identify, among the pathways significantly impacted by the treatment, amino acids metabolism, the TCA cycle, and the glyoxylate pathway. The results highlighted that coumarin was able to interact with membranes reorganisation, delaying them and reducing the production of ATP, as also supported by pathway analysis and cell respiration. The in vivo 31P-NMR analysis supported the hypothesis that the concentration chosen was able to affect plant metabolism, maintaining, on the other hand, its viability, which is extremely important for studying natural compounds’ mode of action.

Metabolic changes induced by Cuscuta campestris Yunck in the host species Artemisia campestris subsp. variabilis (Ten.) Greuter as a strategy for successful parasitisation

“…Macro- and micro-elements contained in shoots portions, collected as previously described [ see Sample collection], were quantified through ICP-MS (BRUKER Aurora-M90 ICP-MS) using the protocol previously described by Araniti et al ( 2022 ).…”

Comparative Metabolomics Profiling Reveals Key Metabolites and Associated Pathways Regulating Tuber Dormancy in White Yam (Dioscorea rotundata Poir.)

“…This also indicates that coumarins prolonged dormancy in the tubers of the long dormant genotype, but induced dormancy breaking process in the tubers of the short dormant genotype. Studies have demonstrated that coumarins induced both primary and secondary seed dormancy [116][117][118]. It has been reported that coumarins induce dormancy due to their ability to antagonize gibberellins and auxin's function, while synergizing with abscisic acid (ABA) [117,119,120].…”

Comparative Metabolomics Profiling Reveals Key Metabolites and Associated Pathways Regulating Tuber Dormancy in White Yam (<em>Dioscorea rotundata</em>)

“…This also indicates that coumarins prolonged dormancy in the tubers of long dormant genotype, but induced dormancy breaking process in the tubers of short dormant genotype. Studies have demonstrated that coumarins induced both primary and secondary seed dormancy [117][118][119]. It has been reported that coumarins induce dormancy due to its ability to antagonize gibberellins and auxin's function, while synergizing with abscisic acid (ABA) [118,120,121].…”