Nikil Badey

Plant transformation through gene editing has reimagined the way we generate plant varieties. Although gene editing systems, such as CRISPR/Cas9, allow for precise genomic mutations to be made, bottlenecks still exist when trying to generate edited plant lines. The most commonly used method in this regard is tissue culture, where you regenerate undifferentiated cells into plants after they have received editing reagents. Regeneration of plants through tissue culture is not ideal for large-scale, high-throughput production of gene edited plants1. The process is often inefficient, requires considerable time, works with limited genotypes, and causes unintended changes to the genome and epigenome. New methods to circumvent these bottlenecks have been developed, namely the ectopic delivery of developmental regulators (DRs) to promote de novo meristem production2.

While these techniques have been shown to be effective, they are still primed for improvements. One way in which this method can be optimized is to modify the DRs to be of more use in a biotechnological setting. One of the key regulators for de novo organogenesis is the transcription factor WUSCHEL (WUS). WUS plays an important role in cell division within the meristem. By altering known functional domains within the WUS coding sequence, novel WUS variants can be tested for use in an applied setting. Using Fast-TrACC as a delivery method, we have examined different domain deletion variants of WUS to determine those most useful for growth induction. This approach revealed that removing the homodimerization domain of WUS induces more ectopic growths on Nicotiana benthamiana seedlings. This insight can be used as a design principle for future improvements in DR based transformation platforms.