Chapter 11 - CRISPR/Cas-mediated genome editing for improved stress tolerance in plants

Abstract

With the growth of the global population (7.3–9.7 billion), crop production needs to be doubled by 2050. Outbreaks of pest and pathogenic biotic stresses and drought, salinity, higher temperature, flooding, and heavy metal abiotic stresses pose a high risk to agricultural production to feed the rapidly growing population under threat of global climate changes. Genome editing technologies are potential tools to revolutionize functional genomics research, and biotic and abiotic stress tolerance in plants. Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-Cas (CRISPR-associated nuclease) is a breakthrough genome editing technology with two classes on the basis of Cas effector module architecture. Class 1 with multisubunit Cas protein complexes is subdivided into type I, III, and IV. Class 2 with a single large Cas protein is subdivided into type II, V, and VI. CRISPR/Cas-based editing in crop trait improvement developments is a fast, cheap, precise, user-friendly, and highly efficient tool against biotic and abiotic stress tolerance. The CRISPR/Cas-mediated genome editing depends on customized Cas endonucleases to create double-stranded breaks at target sites which are repaired by intracellular error-prone nonhomologous end-joining and homology-directed repair pathways in in vivo conditions. This chapter highlights the current knowledge and potential avenues offered by the different types of CRISPR/Cas-mediated genome editing tools in complex traits of abiotic and biotic stresses for the development of stress-tolerant plants with elevated crop productivity and boosted adaptation to changing climate in the future decades.