保存网页 保存网页  打印网页 打印网页   全文下载

2019年12卷22期
《Rice》
页码:1-12

Identification and Characterization of LARGE EMBRYO, a New Gene Controlling Embryo Size in Rice (Oryza sativa L.)

Gileung Lee,Rihua Piao,Yunjoo Lee,Backki Kim,Jeonghwan Seo,Dongryung Lee,Su Jang,Zhuo Jin,Choonseok Lee,Joong Hyoun Chin,Hee-Jong Koh

Department of Plant Science and Research Institute for Agriculture and Life Sciences, and Plant Genomics and Breeding Institute, Seoul National University, Seoul 08826, South Korea

Abstract:

Background

Although embryo accounts for only 2-3% of the total weight of a rice grain, it is a good source of various nutrients for human health. Because enlarged embryo size causes increase of the amount of nutrients and bioactive compounds stored within rice grain, giant embryo mutants of rice (Oryza sativa L.) are excellent genetic resources for improving the nutritional value of rice grains.

Results

Three giant embryo mutants, including large embryo (le), giant embryo (ge) and super-giant embryo (ges), with variable embryo size were used in this study. We investigated whether genes controlling embryo size in these mutants (le, ge and ges) were allelic to each other. Although ge and ges was allelic to GIANT EMBRY (GE), le was not allelic to ge and ges in allelism test. The GE gene carried a unique nucleotide substitution in each of the two mutants (ge and ges), resulting in non-synonymous mutations in exon 2 of GE in both mutants. However, the GE gene of the le mutant did not carry any mutation, suggesting that the enlarged embryo phenotype of le was governed by another gene. Using map-based cloning, we mapped the LE gene to the short arm of chromosome 3. The le mutant showed mild enlargement in embryo size, which resulted from an increase in the size of scutellar parenchyma cells. The LE encodes a C3HC4-type RING finger protein and was expressed to relatively high levels in seeds at a late developmental stage. Knockdown of LE expression using RNA interference increased the embryo size of rice grains, confirming the role of LE in determining the embryo size.

Conclusion

Overall, we identified a new gene controlling embryo size in rice. Phenotypic and molecular characterization results suggest that the le mutant will serve as a valuable resource for developing new rice cultivars with large embryos and nutrient-dense grains.

Keywords: Rice;Large embryo;Giant embryo;C3HC4-type RING finger protein;Nutritional value

保存网页 保存网页  打印网页 打印网页   全文下载