Circadian and diurnal regulation of plant lipid metabolism

Circadian rhythms, driven by an endogenous biological clock, align physiological processes with the Earth's 24-hour light-dark cycle, enabling organisms to adapt to diurnal environmental changes. In plants, the circadian clock regulates key physiological and metabolic processes, such as photosynthesis, nutrient uptake, and stress responses, thereby optimizing growth and development. Recent studies reveal that lipid metabolism is significantly influenced by the circadian clock and diurnal rhythm, which modulate the expression of lipid metabolic genes and ensures rhythmic production and degradation of lipids in response to energy availability and environmental conditions. This review highlights the circadian and diurnal regulation of fatty acid biosynthesis and membrane (phospho/galactolipids), storage (triacylglycerols), and surface (waxes) lipid metabolism in plants, while addressing the broader implications for plant adaptation to environmental changes and extreme stress conditions.