Genome editing in plants using the compact editor CasΦ.

Area of Science:

• Plant science
• Molecular biology
• Biotechnology

Background:

• CRISPR-Cas systems are crucial for plant genome engineering.
• The hypercompact CasΦ nuclease offers a new tool for genetic modification.

Purpose of the Study:

• To evaluate the efficacy and inheritance of CasΦ-mediated gene editing in Arabidopsis.
• To compare the performance of wild-type and variant CasΦ nucleases.
• To assess the specificity and potential of CasΦ in plant genome engineering.

Main Methods:

• CasΦ nuclease and guide RNAs were introduced into Arabidopsis.
• Gene editing efficiency was assessed using the Arabidopsis fwa epiallele.
• DNA methylation's effect on editing efficiency was investigated.
• Off-target edits were analyzed using genomic analysis.

Main Results:

• CasΦ successfully generated stably inherited gene edits in Arabidopsis.
• vCasΦ and nCasΦ variants exhibited significantly higher editing efficiency and heritability than wild-type CasΦ.
• Editing efficiency was influenced by DNA methylation status of the target locus.
• No off-target mutations were detected, indicating high specificity.

Conclusions:

• CasΦ is a potent and specific genome editing tool for plants.
• Optimized CasΦ variants offer improved performance for plant gene editing.
• CasΦ's characteristics make it a valuable addition to existing plant genome engineering toolkits.