What is a repositorium?

The repositorium is a searchable database that provides data on relevant articles from journals, company web pages and web pages of governmental agencies about studies/applications of genome-editing in model plants and agricultural crops in the period January 1996 to May 2018. Search options are article type, technique, plant, traits or free text. The repositorium is based on the systematic map of Dominik Modrzejewski et al., published in the journal environmental evidence. (Download article PDF).

Characterization of paired Cas9 nickases induced mutations in maize mesophyll protoplasts

Typ / Jahr

Journal Article / 2017


Wolter, Felix; Edelmann, Susanne; Kadri, Anan; Scholten, Stefan


Targeted genome modifications are important for both fundamental and applied research. The CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats / CRISPR-associated protein 9) technology has been successfully used in various plant species with high efficiency. Approaches with paired Cas9 nickase enhance the specificity of the CRISPR/Cas9 system by using guide RNA pairs to create two staggered single strand breaks on complementary DNA strands. Here we used maize mesophyll protoplasts as a transient test system and demonstrated the mutagenic potential of Cas9 nickases. Although we found activity for all the three different guide RNA pairs tested, their efficiency varied considerably. Characterization of the modification events revealed a high ratio of large deletions as well as insertions of donor DNA fragments. By the use of the maternally expressed in embryo 1 gene (mee1) as model target sequence, we could demonstrate that transcriptionally inactive and methylated genomic loci are practical targets of Cas9 nickase. The high specificity of Cas9 nickase approaches might provide advantage for genome modifications of certain loci in the complex and highly repetitive maize genome.

genome editing; Protoplasts; Sequence specific nucleases; transient transformation
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ID Corresponding Author
Plant Species GE Technique
Sequence Identifier
Type of Alteration
Progress in Research
Key Topic
845 Scholten, Stefan
Zea mays CRISPR/Cas9
No information
Basic research
Basic research
846 Scholten, Stefan
Zea mays TALENs
No information
Basic research
Basic research