Biochemical Consequences of Climate Change: Effects on Enzyme Stability and Metabolic Homeostasis in Plants

Background: Climate change imposes multifaceted biochemical stressors on plants, including elevated temperatures, increased atmospheric CO₂, and altered precipitation patterns. These environmental shifts disrupt the finely tuned enzymatic and metabolic networks that underlie plant growth, development, and adaptation. Understanding how climate-induced stress affects enzyme stability and metabolic homeostasis is crucial for ensuring crop productivity and ecosystem resilience under future conditions. Methods and Results: This review explores the molecular and biochemical responses of plant systems to climate stress, focusing on the stability, activity, and regulation of key metabolic enzymes. Elevated temperatures destabilize protein tertiary structures, increase proteolytic degradation, and impair cofactor binding, particularly in thermolabile enzymes involved in photosynthesis and respiration, such as Rubisco, PEPC, and cytochrome oxidases. Concurrently, oxidative stress induced by reactive oxygen species alters redox-sensitive signaling pathways and post-translational modifications, including S-nitrosylation and thiol oxidation. Shifts in stomatal conductance under increased CO₂ levels affect carbon fixation dynamics, while drought and salinity impose osmotic stress that perturbs amino acid, sugar, and polyol metabolism. Multi-omics profiling reveals reprogramming of metabolic fluxes and activation of stress-responsive gene networks that modulate enzymatic adaptation. Genetic engineering and directed evolution strategies are being employed to develop enzyme variants with enhanced thermal and redox stability. Conclusion: The biochemical integrity of plant metabolism is increasingly vulnerable to climate change-driven perturbations. By elucidating how abiotic stressors affect enzyme structure and function, researchers can inform the development of climate-resilient crops through systems-based metabolic engineering and stress-adaptive breeding programs.