Multi-omics exploration of the involvement of ABA in identifying unique molecular markers for single and combined stresses in tomato plants.

Over the past decade, there has been increasing evidence that plant responses to combined abiotic stresses are unique and cannot be inferred from studying plants exposed to individual stresses. Understanding how adaptative plant mechanisms integrate from stress perception to biochemical and physiological adjustments is a major challenge in abiotic stress signaling studies. Considering abscisic acid (ABA) as a key regulator in plant abiotic stress responses, ABA-deficient plants (flc) exposed to single or combined salinity and heat stresses were evaluated and different -omics analyses were conducted. Significant changes in biomass, photosynthesis, ions, transcripts, and metabolites occurred in mutant plants under single or combined stresses. Exogenous ABA application in flc mutants did not fully recover plant phenotypes or metabolic levels but induced cellular reprogramming with changes in specific markers. Multi-omics analysis aimed to identify ABA-dependent, ABA-independent, or stress-dependent markers in plant responses to single or combined stresses. We demonstrated that studying different -omics as a whole led to the identification of specific markers for each stress condition that were not detectable when each -omic was studied individually. These findings may be utilized to enhance crop resilience to heat waves, salinity, and their combination, contributing to addressing food security challenges in a climate change scenario. Future exploration of the transcriptomic, ionomic, and metabolomic data presented in this study could lead to the identification of new pathways and genes associated with ABA signaling processes.