Salinity and chilling stresses are known to adversely affect plant growth and development, resulting in major losses in crop production worldwide. Salt stress inhibits growth and development and leads to a reduction in the transport of assimilates. Chilling stress affects the maintenance of the sugar supply of sink organ, which is essential for plant survival. However, the plants’ responses to salinity and chilling stress combination are rarely studied. Grafting has been demonstrated as a promising tool to broaden the tolerance of crops to abiotic stresses. The knowledge of plants’ metabolic alterations in response to combined salinity and chilling stress is urgently needed to reveal biomarkers related to the mechanism of plant tolerance to abiotic stress combinations.
In this study, we employed an untargeted gas chromatography-mass spectrometry (GC-MS) based approach to explore the tissue-specific metabolic alterations at different growth stages of tomato plants under combined salinity and chilling stresses. Three tomato varieties were selected, and one of the lines was a scion being grafted on itself and the other two. Both leaf and root samples were collected after 14 days and 49 days of stress treatments, which represent vegetative and reproductive growth stages, respectively. We observed significant tissue-specific and growth-stage-specific alterations of metabolites in the glycolysis pathway and Krebs cycles under the stress conditions, highlighting the significance of seeking abiotic stress biomarkers in tissue and plant developmental stage aspects.