Metabolite profiling of the oilseed crop Ricinus communis during early seed imbibition reveals a specific metabolic signature in response to temperature

•GC–MS based profiling of Ricinus communis seeds revealed the presence of 39 compounds.•A shift in the carbon and nitrogen metabolism is the main response to high temperatures during seed imbibition.•Lipolysis and gluconeogenesis are enhanced during imbibition at 20 and 25 °C.•Variation in ascorbate content during imbibition suggests that seeds perceive 35 °C as a stress condition.

Seed imbibition is an important process in the plant life cycle and determines whether seed germination and plant growth will be successful or not. Ricinus communis is becoming an important crop for oil production, and therefore, studying the physiological and biochemical aspects of seed imbibition and germination may aid in the improvement of crop quality and yield. Metabolite profiling was performed in order to assess biochemical changes associated with the temperature during early seed imbibition. Changes in the metabolite profile were already detected within 2 h of imbibition, but they were more prominent after 8 h. An increased level of glycerol and fatty acids upon a few hours of imbibition suggests that lipid mobilization occurs shortly after water uptake begins. Fumarate and succinate levels increased after 2 h of imbibition, suggesting that energy metabolism is reactivated relatively early in this species. Seeds imbibed at 20 and 25 °C showed an overall accumulation of carbohydrates, while at 35 °C increased levels of some amino acids were observed. Ascorbate content was 30-fold higher in seeds imbibed for 8 h at 35 °C as compared to seeds imbibed at 20 °C, suggesting that 35 °C is a stress condition for R. communis seeds. In this study, we have demonstrated that temperature plays an important role in water uptake rate, reserve mobilization and reactivation of metabolism during early seed imbibition. Additionally, we demonstrated that this species possess a specific metabolic signature which is not restricted to the imbibition period, but also during seedling establishment and plant growth.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide