Overexpression of RAG2 Improves Grain Yield and Quality of Rice

Increasing grain yield and improving grain quality are the primary goals for rice breeding. Hence, understanding the factors that contribute to the grain quantity and nutrition of rice will be the basis for developing new breeding strategies. RAG2 is an inhibitor of 14-to-16-kDa α-amylase/trypsin in rice, which are the albumin of seed storage proteins. The research team of Wei Zhou from Huazhong Agricultural University in China aimed to study the effect of RGA2 on rice yield.

The team found that RAG2 was specifically expressed in ripening seeds and its transcription peak was between 14 and 21 days after flowering. When overexpressed, the grain size and 1000-grain weight significantly increased in RAG2-overexpressed lines compared with wild type. On the contrary, grain size was reduced in RAG2-suppressed lines. The protein content and amount of total lipids were also increased and decreased in the seeds of RAG2-overexpressing and RAG2-suppressed lines, respectively.

Overexpression of RAG2 significantly increased grain size and improved grain quality and yield simultaneously. These results suggest that RAG2 plays a vital role in regulating grain weight and seed quality of rice.

For more on this study, read the full article in Plant Biotechnology Journal.