CRISPR-Cas9 Speeds Up Domestication of African Rice Landraces

Researchers from the University of Milan developed protocols for genetic transformation of African rice varieties to enable the use of CRISPR-Cas9.

African Oryza glaberrima and Oryza sativa are known to be valuable sources of favorable traits because of their adaptation to the continent's extreme environmental conditions. These varieties exhibit superior resistance to endemic pests and tolerance to drought and nutrient deficiencies compared to Asian rice varieties. However, "domestication traits" including seed shattering, lodging, and seed yield are not well established in these African landraces. Thus, the use of these African varieties for high production agriculture is limited by unpredictable yield and grain quality. To address this concern, the researchers developed protocols for the improvement of the African rice landraces using CRISPR-Cas9.

As proof of concept, they used African landrace Kabre to target the "domestication loci" and enhance its agronomic potential. Genetic transformation with CRISPR-Cas9-based vectors led to single and simultaneous several gene knockouts. Plants with reduced height to decrease lodging were generated by disrupting the HTD1 gene. The researchers detected three loci that control seed size and/or yield then targeted them using a multiplex CRISPR-Cas9 construct. This led to mutants with significantly enhanced seed yield.

Read the research article in Plos One.