Biotech Updates

Dominant Allele Restricts Nodulation of Rhizobium Species in Soybean

April 25, 2018

Sinorhizobium fredii is a rhizobial species that can establish a nitrogen-fixing symbiosis with a wide range of legume species. In soybean (Glycine max), this interaction shows a high level of specificity since S. fredii strains nodulate only on a limited set of soybean genotypes. The team of Yinglun Fan from the Liaocheng University in China identified a gene in soybean that restricts nodulation with S. fredii USDA193.

Using complementation tests as well as the CRISPR-Cas9 knock-out, the team found that the Rfg1 allele was responsible for resistance to nodulation by S. fredii USDA193. in previous studies, the Rfg1 allele was found to encode a class of plant resistance protein that restricts nodulation by S. fredii strains USDA257 and USDA205. Another version of this gene also restricts nodulation by Bradyrhizobium japonicum strain USDA122.

The Rfg1 allele likely provides broad-spectrum resistance to nodulation in soybeans.

For more information, read the article in Frontiers in Plant Science.