Identification of the biochemical characteristics of developing giant embryo rice grains using non-targeted metabolomics

Abstract

Giant embryo rice is well known for its high content of nutrients, such as GABA. However, the biochemical characteristics of this grain remain un-elucidated, and little is known about whether additional types of nutritional chemicals accumulate in giant embryo rice. In this study, we compared the metabolome of the developing grain of giant embryo rice, namely, ‘Shangshida No. 5‘, to that of normal embryo rice, namely, ‘Chao2-10‘, using a non-targeted metabolomics approach. Our results showed that more additional nutrients and bioactive compounds that had not been reported previously in other giant embryo rice, such as reduced glutathione, β-alanine, VB6, arabinose, xylitol, and xylose, were present in ‘Shangshida No. 5’ than in ‘Chao2-10‘. Specifically, the amount of β-alanine in ‘Shangshida No. 5’ was 18.71 times that in ‘Chao2-10’ at 45 DAF. These analyses suggest that ‘Shangshida No. 5’ is a high-quality functional rice, and has potential applications in rice nutritional improvements.