CRISPR-TSKO: A technique for efficient mutagenesis in specific cell types, tissues, or organs in Arabidopsis ($) (Plant Cell)

The ability to introduce base-specific changes through CRISPR/Cas9 gene editing has given scientists fantastic tools with which to understand and modify the genes that control plant development and physiology. New tools and refinements to this toolkit are being developed rapidly. In this new work, Decaestecker et al. introduce CRISPR-TSKO (tissue-specific knockout system). The power of this new method is that gene editing can occur in a very limited subset of cells or tissues, which is invaluable when studying genes that might be lethal when knocked out in all tissues (about 10% of Arabidopsis genes are indispensable). The tissue specificity is conferred by expressing Cas9 nuclease from tissue-specific promoters. The authors started by knocking out GFP as a proof-of-concept and then expanded to test several known regulatory genes. Constructs are available from the authors or Addgene, and detailed cloning protocols are provided. (Summary by Mary Williams) Plant Cell 10.1105/tpc.19.00454