Ionomic and metabolomic analyses reveal association between nutritional value and aleurone layer thickness in rice

The fortification of aleurone cells represents a promising avenue for enhancing the nutritional quality of cereal. This study investigated dorsal aleurone thickness (DAT) in a rice diversity panel comprising 180 varieties, revealing that DAT of the Geng subspecies is typically greater than that of the Xian subspecies. The minerals and primary metabolites accumulated in the brown grains of ten rice varieties exhibiting distinct DAT were subjected to analysis using spectrometry-based technologies. A positive correlation was identified between essential mineral zinc and DAT, whereas toxic mineral cadmium exhibited a negative correlation. Moreover, our findings revealed that the Xian varieties with high DAT exhibited greater lipid accumulation in the brown seeds than those with thin DAT, while the Geng varieties with high DAT predominantly influenced amino acid accumulation. The findings suggest that the natural variations in aleurone thickness may be exploited for the development of rice varieties that are enriched in nutrients.