Understanding of Molecular Mechanisms and Breeding Strategies for Enhancing Oleic Acid Biosynthesis in Oil Crops

ABSTRACT

Oleic acid (C18:1), a monounsaturated fatty acid, is a key determinant of nutritional value and oxidative stability of vegetable oils. Increasing its concentration has therefore become a central objective in oilseed crop improvement. This review summarizes current knowledge on the molecular mechanisms and breeding strategies underlying oleic acid biosynthesis in oil crops. Particular attention is given to fatty acid metabolism, including fatty acid desaturase 2  ( FAD2 ),  acetyl‐CoA carboxylase ( ACCase ),  diacylglycerol acyltransferase ( DGAT ), and  stearoyl‐ACP desaturase ( SAD ). Among these, FAD2  plays a pivotal role by catalyzing the conversion of oleic acid to linoleic acid and thus largely determining oleic acid accumulation. We also discuss how environmental factors, including temperature and water availability, influence desaturase activity and oil composition. In addition, conventional breeding approaches and modern molecular breeding strategies, such as marker‐assisted selection (MAS), genomic approaches and CRISPR/Cas‐based genome editing, are evaluated for their effectiveness in enhancing oleic acid content in oilseed crops. Finally, we highlight emerging opportunities that integrate genomics, multi‐omics, and artificial intelligence to accelerate the development of high‐oleic cultivars. This review provides a comprehensive framework for improving oleic acid content and advancing oilseed crop breeding.