Manipulating mRNA splicing by base editing in plants
Precursor-mRNAs (pre-mRNA) can be processed into one or more mature mRNA isoforms through constitutive or alternative splicing pathways. Constitutive splicing of pre-mRNA plays critical roles in gene expressional regulation, such as intron-mediated enhancement (IME), whereas alternative splicing (AS) dramatically increases the protein diversity and gene functional regulation. However, the unavailability of mutants for individual spliced isoforms in plants has been a major limitation in studying the function of mRNA splicing. Here, we describe an efficient tool for manipulating the splicing of plant genes. Using a Cas9-directed base editor, we converted the 5′ splice sites in four Arabidopsis genes from the activated GT form to the inactive AT form. Silencing the AS of HAB1.1 (encoding a type 2C phosphatase) validated its function in abscisic acid signaling, while perturbing the AS of RS31A revealed its functional involvement in plant response to genotoxic treatment for the first time. Lastly, altering the constitutive splicing of Act2 via base editing facilitated the analysis of IME. This strategy provides an efficient tool for investigating the function and regulation of gene splicing in plants and other eukaryotes.
keywordsbase editing splicing intron retention alternative 5′ splicing site
Unable to display preview. Download preview PDF.
This work was supported by grants from the National Key Research and Development Program of China (2016YFD0101804), the National Natural Science Foundation of China (31788103 and 31420103912), as well as the Chinese Academy of Sciences (QYZDY-SSW-SMC030 and GJHZ1602).