Control of Plant Viruses by CRISPR/Cas System-Mediated Adaptive Immunity.

Yongsen Cao,Fangfang Li,Xueping Zhou,Huanbin Zhou

doi:10.3389/fmicb.2020.593700

Abstract

Plant diseases caused by invading plant viruses pose serious threats to agricultural production in the world, and the antiviral engineering initiated by molecular biotechnology has been an effective strategy to prevent and control plant viruses. Recent advances in clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) system-mediated DNA or RNA editing/interference in plants make them very attractive tools applicable to the plant protection field. Here, we review the development of CRISPR/Cas systems and summarize their applications in controlling different plant viruses by targeting viral sequences or host susceptibility genes. We list some potential recessive resistance genes that can be utilized in antiviral breeding and emphasize the importance and promise of recessive resistance gene-based antiviral breeding to generate transgene-free plants without developmental defects. Finally, we discuss the challenges and opportunities for the application of CRISPR/Cas techniques in the prevention and control of plant viruses in the field.

Highlights

Plant diseases caused by plant pathogens, including bacteria, fungi, nematodes, and viruses in different crops, lead to enormous economic losses worldwide
The sgRNAs targeting the stem-loop sequence compared to the sgRNAs targeting the viral coat protein (CP) region and the replicationassociated region within the intergenic region (IR) displayed a more effective interference of several geminiviruses including the monopartite geminivirus, cotton leaf curl Kokhran virus (CLCuKoV), the bipartite geminivirus, Merremia mosaic virus (MeMV), and different severe and mild strains of tomato yellow leaf curl virus (TYLCV) geminiviruses (Ali et al, 2016). These findings suggest that clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9-induced variants in open reading frames (ORFs) but not the IR of geminiviruses are capable of replication and systemic movement, thereby evading the CRISPR/Cas9 machinery
Molecular breeding has played a pivotal role in the prevention and control of plant viruses causing diseases, and the emergence and development of CRISPR/Cas technologies would speed up the generation and obtainment of new resistance resources

Summary

Introduction

Plant diseases caused by plant pathogens, including bacteria, fungi, nematodes, and viruses in different crops, lead to enormous economic losses worldwide. CRISPR/Cas9 constructs with single guide RNAs (sgRNAs) targeting the viral replication-associated region, or intergenic region (IR), have exhibited effective DNA interference and conferred viral resistance against beet severe curly top virus (BSCTV), cotton leaf curl Multan virus (CLCuMuV), and bean yellow dwarf virus (BeYDV) in transgenic Nicotiana benthamiana or Arabidopsis thaliana plants, respectively (Baltes et al, 2015; Ji et al, 2015; Yin et al, 2019).

Results

Conclusion