Crop Biotech Update

GS9 Regulates Rice Grain Shape and Appearance

July 11, 2018

Identifying genes that determine grain shape can greatly help the breeding of better rice cultivars. Thus, Dong-Sheng Zhao from Yangzhou University in China and team studied the Grain Shape Gene on Chromosome 9 (GS9) and its role in grain shape of rice. To further study the gene, the team developed both GS9-overexpressing and CRISPR-edited gs9 null mutants. The resulting gs9 mutants exhibited slender grains, while overexpression GS9 resulted in round grains.

Further analysis found that GS9 regulates grain shape by altering cell division. The GS9 protein was also found to interact with ovate family proteins. Genetic interaction analysis reveals that GS9 functions independently from other previously identified grain size genes. Introducing the gs9 allele into elite rice cultivars significantly improved grain shape and appearance.

The study suggests a potential application of gs9, alone or in combination with other grain size determining genes, in breeding rice varieties with optimized grain shape.

For more information, read the article in Nature Communications.