Comparative metabolomics analysis reveals the variations of eating quality among three high-quality rice cultivars

Good eating quality is a highly desirable trait of rice which determines its commercial value and market share. However, the molecular basis of this trait remains largely unknown. Here, three high-quality conventional rice cultivars, including two superior eating quality cultivars Meixiangzhan-2 (MXZ) and Xiangyaxiangzhan (XYXZ), and one ordinary eating quality cultivar Huanghuazhan (HHZ), were analyzed by comparative metabolomics to identify the inherent mechanism for the formation of superior eating quality. The results showed 58.8% of common differential substances between MXZ vs HHZ and XYXZ vs HHZ were enriched in MXZ and XYXZ, whereas 39.2% of them were prominently decreased compared with HHZ, mainly including amino acids, carbohydrates, lipids, phenolamides, and flavonoids, which may be the primary factors leading to the differences of taste and flavor among these three cultivars. We also found that lysine derivatives and fatty acids may have a close relationship with taste. These results above provide important insights into the taste-forming mechanism of rice and will be beneficial for superior eating quality rice breeding.