Genome editing tools for cotton: In 2018, we developed CRISPR/Cas 9 system with an average 65-85% efficiency in cotton. Then, we performed the whole genome sequencing to investigate the off-target in the CRISPR/Cas9 edited cotton plants. Then, we further developed a high-throughput genome editing system in cotton. A sgRNAs library (containing 1100 sgRNAs targeted to 600 independent genes) was constructed and cloned into the CRISPR/Cas 9 vector. Recently, CRISPR/Cas12a/Cas12b were developed with features distinct from those of Cas9 and both work very well with high efficiency and accuracy in cotton. At the same time, we developed several base editing tools (CBE, ABE8e, Dural base editor) for cotton creating specific point mutations. Most recently, several CRISPR/Cas13 systems (13a, b, c, d) were developed in cotton to target the RNA for down-regulating the gene transcription (knock-down). On the contrary, a transcription activation (dCas9-TV) system was establishing by fusion transcriptional activators with dCas9 to knock-up gene’s transcription.
Cotton Molecular Breeding using Genome editing: The high oleic acid content cotton was generated by knockout of GhFAD2 genes with CRISPR/Cas9 system. Similarly, by targeting GhPGF with Cas12, we efficiently created non-transgenic and gossypol-free cotton plants. Moreover, we have extended the application of base editors to cotton plants by editing the GhTFL1 gene to create ideotype cotton germplasm. In addition, an in vivo maternal haploid induction system was developed in cotton by knock out the GhDMP . Most recently, the optimized dCas9-TV system was recruited to activate the GhEPSPS to generate glyphosate-resistant cotton.