CRISPR-Cas genome editing system: A versatile tool for developing disease resistant crops

The crop productivity is seriously threatened by phyto-pathogens like virus, bacteria and fungi, causing more than 30-40% of crop loss globally. Developing disease resistant crop varieties is very much essential to meet the increasing population. In order to develop disease resistant crops, several technologies have been applied. Among which the genome editing tool, clustered regularly interspaced short palindromic repeat CRISPR-associated protein 9 (CRISPR/Cas9) has revolutionizing the plant research. In this review, we cover the exploitation of CRISPR genome editing (GE) tool for developing plant disease resistance to virus, bacteria and fungi. Several disease susceptibility, recessive, negatively regulated genes and transcription factors have been discovered in host plants which have potential role in compatible interaction with pathogens. These genes were edited in different plants like rice, wheat, cucumber, cassava, cacao, grapes, citrus, apple, banana etc. for improving disease resistance. In addition, we discussed applications and limitations in developing transgene free disease resistant crops.