Guide RNA library-based CRISPR screens in plants: opportunities and challenges

Next-generation sequencing technologies have revolutionized our ability to read sequence information at the genome and transcriptome levels in a high-throughput manner. However, genetic screening at a large or genomic scale remains challenging in plants. Recently, the RNA-guided CRISPR-Cas nucleases have been optimized for high-throughput functional genomic screens combined with guide RNA (gRNA) libraries in plants. This approach has shown great promise in facilitating genetic screening, directed evolution, and quantitative trait engineering. However, this technology is still in its infancy. In this short review, we describe the recent progress in gRNA library-based CRISPR screens in plants. We provide a critical assessment of the current approaches and emerging delivery methods for CRISPR screens. We also highlight the challenges and present future perspectives on CRISPR screens in plants.