Gene Editing Produces Blast-Resistant Rice

Blast, caused by the fungus Magnaporthe oryzae, is the most destructive rice disease occurring throughout Brazil. A study by Embrapa Genetic Resources and Biotechnology used the gene editing CRISPR-Cas9 technique to give blast resistance to the rice cultivar BRSMG Curinga.

Launched in 2005, BRSMG Curinga was replaced in the market after becoming susceptible to the blast disease over the years. The technology resulting from knocking out two target genes related to blast is still in its testing stage but has the potential to reach the market in a few years. Researcher Angela Mehta said that once cultivars like BRSMG Curinga are released to the market as resistant or tolerant to blast, they become susceptible in a few years. Their study compared a susceptible rice genotype with a resistant genotype in search of proteins that become more abundant in the susceptible plant after the pathogen infects it.

The researchers identified three genes that are capable of such knockout, two of which were validated during Fabiano Távora's sandwich doctorate, which was supervised by Mehta and carried out at the French Agricultural Research Centre for International Development (CIRAD). By knocking out those genes in the Kitaake rice variety, which is considered a model, Távora found that the plant became slightly more resistant to blast. The researchers used one of those genes as a target and selected two others to create a combination of targets to knock out two genes at once, in two different builds in BRSMG Curinga. The study resulted in two blast-resistant rice lines (one for each build), presenting mutations for the two target genes.

For more details, read the news article in Embrapa News.