Recent Advances in Synthesis Regulation, Quality Effect, and Genetic Improvement Strategies of Rice Grain Lipids

Rice grain lipids, though constituting a minor fraction of brown rice weight, exert a pivotal influence on grain quality, encompassing eating and cooking quality, nutritional value, and storage stability. Lipids are unevenly distributed within the caryopsis, predominantly localized in the embryo and aleurone layers, and consist of neutral triacylglycerols and polar glycerolipids with a characteristic fatty acid profile rich in oleic, linoleic, and palmitic acids. The application of advanced lipidomics and imaging techniques, such as liquid chromatography-mass spectrometry, matrix-assisted laser desorption/ionization mass spectrometry imaging, and nuclear magnetic resonance, has enabled detailed profiling and spatial visualization of lipid species, revealing their interactions with starch and proteins. Molecular studies have identified key genes ( OsFAD2 , OsLOX , OsPLDα1 , OsWRI1 ), enzymes, and QTLs that govern lipid content, composition, and stability. Grain lipids determine eating quality by forming amylose-lipid complexes that influence texture, digestibility, and aroma, while their oxidative degradation, mediated by lipases and lipoxygenases, is a primary cause of quality deterioration during storage. Genetic strategies, including breeding for high-oleic acid, lipoxygenase-null, or high-lysophospholipid genotypes via genetic engineering, and biotechnological interventions are emerging as powerful tools to tailor lipid profiles for enhanced palatability, extended shelf life, and improved nutritional outcomes. Consequently, integrating lipid-centric approaches with traditional starch- and protein-focused breeding paradigms is essential for the holistic improvement of rice quality in the future.