Deciphering Cold Stress Resilience: Multiomics Insights in Contrasting Wheat Genotypes From the Western Himalayas

Cold stress threatens wheat productivity, particularly in regions with extreme climatic conditions. To elucidate the molecular mechanisms underlying wheat's response to cold stress, we performed a multiomics analysis integrating lipidomics, transcriptomics, proteomics and metabolomics. Our study focused on two wheat genotypes with contrasting cold tolerance levels, SKAU_52 (tolerant) and SKAU_4301 (susceptible) to capture genotype-specific responses under cold stress. Lipidomic analysis revealed significant changes in lipid composition, with unsaturated lipids such as digalactosyldiacyl glycerols (DGDGs) and monogalactosyldiacylglycerols (MGDGs) upregulated in response to cold stress. These lipids are associated with maintaining membrane fluidity, whereas saturated lipids were downregulated in the cold-tolerant genotype. Transcriptomics analysis provides a strong evidence that cold tolerance in wheat is governed by coordinated activation of the ICE-CBF-COR regulatory cascade, with the cold-tolerant genotype 'SKAU_52' showing stronger and more sustained induction across pathway tiers than the cold susceptible wheat genotype 'SKAU_4301'. Similarly, proteomic data highlighted differential abundance of proteins involved in antioxidative defence, osmotic adjustment and signal transduction, including late embryogenesis abundant (LEA) proteins. Metabolome assessment revealed substantial alterations in carbohydrate and amino acid metabolism, with sucrose and amino acids such as hydroxyproline identified as key contributors to cold tolerance. Additionally, defence hormones such as salicylic acid (SA), jasmonic acid (JA) and abscisic acid (ABA) exhibited genotype-specific regulation with higher accumulation in cold-tolerant genotype. Overall, this integrated multi-omics approach provides novel insights into the complex molecular mechanisms underlying cold stress adaptation in wheat, supporting the development of resilient wheat varieties capable of thriving in challenging cold environments.