Reducing Arsenic Accumulation in Rice with Gene Editing

Nanjing Agricultural University scientists explored using gene-editing tool CRISPR-Cas9 to minimize arsenic build-up in rice grains. Environmental Science and Technology journal reports their findings.
Rice, the top staple for many countries, is exposed to inorganic arsenic in the soil. Reducing the build-up of arsenic in rice grains is vital in delivering safer rice grains. The researchers edited the genes involved in silicon uptake in rice roots to reduce arsenic absorption. The transporters genes for silicon uptake, OsLsi1 and OsLsi2, also inadvertently take up arsenic in soil water. Thus, they edited the promoter region of OsLsi1 and the coding sequence of both genes, generating 27 mutant rice lines.
The researchers reported that deleting a portion of the promoter region of OsLsi1 led to reduced silicon uptake, without impacting arsenic uptake of arsenic levels in the grains. Mutations in both OsLsi1 and OsLsi2 coding sequences led to decreased silicon and arsenic uptake and silicon accumulation in husks. OsLsi2 mutations did not affect rice yield.
(Source: Crop Biotech Update, International Service for Acquisition of Agri-Biotech Applications. www.isaaa.org)