Conserved mechanisms of plant lipidome remodeling under heat and cold stresses revealed through a systematic review and meta-analysis

Increasing temperature fluctuations threaten crop productivity worldwide, emphasizing the need for a deeper understanding of plant adaptation to such extremes. Lipids are fundamental biological molecules that furnish structural, metabolic, and regulatory roles in plant growth and development, and responses to environmental stresses. The potential of lipids as key targets for crop improvement under changing climates is emerging. This systematic review and meta-analysis presents comprehensive syntheses of current knowledge on plant lipidome responses to heat and cold stresses. The analysis reveals conserved lipidomic responses to heat and cold stresses across plant species, tissue types, and growth stages. The decreased levels of lipids with relatively smaller head groups [e.g. monogalactosyldiacylglycerol (MGDG) and phosphatidylethanolamine (PE)] that promote membrane bilayer structure, a decrease in unsaturation index in membrane lipids, and sequestration of polyunsaturated acyl chains into neutral lipids (e.g. triacylglycerols) emerged as conserved strategies for heat adaptation. Also, very-long-chain fatty acids were identified as important in heat stress adaptation, as their presence is likely to counteract excessive membrane fluidity caused by high temperature and to maintain membrane stability under heat stress. Under cold stress, the levels of membrane lipids containing polyunsaturated acyl chains were elevated, probably as an adaptive shift favoring more fluid, flexible membranes. Further, the levels of bilayer-forming lipids [e.g. digalactosyldiacylglycerol (DGDG)] increased and those of non-bilayer-forming lipids (e.g. MGDG) decreased. Overall, this article synthesizes knowledge of lipidome remodeling in plants and its role in resilience to temperature stress, identifying priority areas for future research to support climate-resilient agriculture.