title: CRISPR/Cas9-mediated viral interference in plants.
abstract: BACKGROUND
  The CRISPR/Cas9 system provides bacteria and archaea with molecular immunity against invading phages and conjugative plasmids. Recently, CRISPR/Cas9 has been used for targeted genome editing in diverse eukaryotic species.
  
  
  RESULTS
  In this study, we investigate whether the CRISPR/Cas9 system could be used in plants to confer molecular immunity against DNA viruses. We deliver sgRNAs specific for coding and non-coding sequences of tomato yellow leaf curl virus (TYLCV) into Nicotiana benthamiana plants stably overexpressing the Cas9 endonuclease, and subsequently challenge these plants with TYLCV. Our data demonstrate that the CRISPR/Cas9 system targeted TYLCV for degradation and introduced mutations at the target sequences. All tested sgRNAs exhibit interference activity, but those targeting the stem-loop sequence within the TYLCV origin of replication in the intergenic region (IR) are the most effective. N. benthamiana plants expressing CRISPR/Cas9 exhibit delayed or reduced accumulation of viral DNA, abolishing or significantly attenuating symptoms of infection. Moreover, this system could simultaneously target multiple DNA viruses.
  
  
  CONCLUSIONS
  These data establish the efficacy of the CRISPR/Cas9 system for viral interference in plants, thereby extending the utility of this technology and opening the possibility of producing plants resistant to multiple viral infections.
authors.affiliation: Laboratory for Genome Engineering, Center for Desert Agriculture & Division of Biological Sciences, 4700 King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia.
authors.forename: Zahir
authors.initials: Z
authors.lastname: Ali
authors.affiliation: Laboratory for Genome Engineering, Center for Desert Agriculture & Division of Biological Sciences, 4700 King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia.
authors.forename: Aala
authors.initials: A
authors.lastname: Abulfaraj
authors.affiliation: Laboratory for Genome Engineering, Center for Desert Agriculture & Division of Biological Sciences, 4700 King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia.
authors.forename: Ali
authors.initials: A
authors.lastname: Idris
authors.affiliation: Laboratory for Genome Engineering, Center for Desert Agriculture & Division of Biological Sciences, 4700 King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia.
authors.forename: Shakila
authors.initials: S
authors.lastname: Ali
authors.affiliation: Laboratory for Genome Engineering, Center for Desert Agriculture & Division of Biological Sciences, 4700 King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia.
authors.forename: Manal
authors.initials: M
authors.lastname: Tashkandi
authors.affiliation: Laboratory for Genome Engineering, Center for Desert Agriculture & Division of Biological Sciences, 4700 King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia. magdy.mahfouz@kaust.edu.sa.
authors.forename: Magdy M
authors.initials: MM
authors.lastname: Mahfouz
mesh_terms: D053839:Begomovirus / Q000235:genetics*; D064130:CRISPR-Associated Proteins / Q000378:metabolism; D064113:CRISPR-Cas Systems; D060467:Disease Resistance / Q000235:genetics; D004706:Endodeoxyribonucleases / Q000378:metabolism; D016679:Genome, Viral; D010935:Plant Diseases / Q000517:prevention & control* / Q000821:virology*; D014026:Nicotiana / Q000821:virology
chemical_list: D064130:CRISPR-Associated Proteins; D004706:Endodeoxyribonucleases