Multi-Omics Exploration of ABA Involvement in Identifying Unique Molecular Markers for Single and Combined Stresses in tomato plants

Abstract

Over the past decade, our research group has found that plant responses to combined abiotic stresses are unique and cannot be inferred from studying plants exposed to individual stresses. Adaptive mechanisms involve changes in gene expression, ion regulation, hormonal balance, and metabolite biosynthesis or degradation. Understanding how these mechanisms integrate from stress perception to biochemical and physiological adjustments is a major challenge in abiotic stress signaling studies. Today, vast amounts of -omics data (genomics, transcriptomics, proteomics, metabolomics, phenomics) are readily available. Additonally, each –omic level is regulated and influenced by the others, highlighting the complexity of plant metabolism's response to stress. Considering abscisic acid (ABA) as a key regulator in plant abiotic stress responses, in our study, 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 together identifies specific markers for each stress condition not detectable individually. Our findings provide insight into specific metabolic markers in plant responses to single and combined stresses, highlighting specific regulation of metabolic pathways, ion absorption, and physiological responses crucial for plant tolerance to climate change.