Genetic engineering including genome editing for broad-spectrum disease resistance in crops.

Abstract

Plant diseases, caused by a wide range of pathogens, severely reduce crop yield, quality and pose a threat to global food security. Developing broad-spectrum resistance (BSR) in crops is a key strategy to control crop diseases and safeguard crop production. Cloning of disease-resistance (R) genes and understanding their underlying molecular mechanisms provides new genetic resources and strategies for crop breeding. Novel genetic engineering and genome editing tools have accelerated the study of BSR genes and engineering of BSR in crops, and this area represents the primary focus of this review. We first summarize recent advances in the understanding of the plant immune system. We then examine progress in understanding molecular mechanisms underlying BSR in crops. Finally, we highlight diverse strategies employed to achieve BSR, such as gene stacking to combine multiple R genes, multiplexed genome editing of susceptibility (S) genes and promoters of executor R genes, editing cis-regulatory elements for fine-tuning gene expression, RNA interference, saturation mutagenesis, and precise genomic insertions. Genetic studies and engineering of BSR accelerate breeding of disease-resistant cultivars and crop improvement, which will act to safeguard global food security.