Genetic Databases and Gene Editing Tools for Enhancing Crop Resistance against Abiotic Stress

Abstract

Abiotic stresses extensively reduce agricultural crop production globally. Traditional breeding technology has been the fundamental approach used to cope with abiotic stresses. The development of gene editing technology for modifying genes responsible for the stresses and the related genetic networks has established the foundation for sustainable agriculture against environmental stress. Integrated approaches based on functional genomics and transcriptomics are now expanding the opportunities to elucidate the molecular mechanisms underlying abiotic stress responses. This review summarizes some of the features and weblinks of plant genome databases related to abiotic stress genes utilized for improving crops. The gene-editing tool based on clustered, regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) has revolutionized stress tolerance research due to its simplicity, versatility, adaptability, flexibility, and broader applications. However, off-target and low cleavage efficiency hinder the successful application of CRISPR/Cas systems. Computational tools have been developed for designing highly competent gRNA with better cleavage efficiency. This powerful genome editing tool offers tremendous crop improvement opportunities, overcoming conventional breeding techniques' shortcomings. Furthermore, we also discuss the mechanistic insights of the CRISPR/Cas9-based genome editing technology. This review focused on the current advances in understanding plant species' abiotic stress response mechanism and applying the CRISPR/Cas system genome editing technology to develop crop resilience against drought, salinity, temperature, heavy metals, and herbicides.

Keywords: CRISPR/Cas9; abiotic stress; genome databases; genome editing.

Figure 1

Schematic illustration of the mechanism of genome editing using CRISPR/Cas9 system. The single guide RNA (sgRNA)/CRISPR-associated protein 9 (Cas9) complex binds to the target site at a complementary region of the genomic DNA. The protospacer adjacent motif (PAM) is recognized by Cas9 nuclease, which introduces the double-stranded breaks (DSBs) within the target DNA at a site three base pair upstream to the PAM. Double-stranded breaks (DSBs) of the target DNA are repaired by non-homologous end joining (NHEJ), resulting InDel mutations (insertion or deletion) or homology-directed repair (HDR) in the presence of a donor DNA, resulting in precise gene editing.