Modified carbon dot-mediated transient transformation for genomic and epigenomic studies in wheat

Genotype restriction poses a significant bottleneck to stable transformation in the vast majority of plant species, thereby severely impeding advancement in plant bioengineering, particularly for crops. Nanoparticles (NPs) can serve as effective carriers for the transient delivery of nucleic acids, facilitating gene overexpression or silencing in plants in a genotype-independent manner. However, the applications of NP-mediated transient systems in comprehensive genomic studies remained underexplored in plants, especially in crops that face challenges in genetic transformation. Consequently, there is an urgent need for efficient NP-mediated delivery systems capable of generating whole plants or seedlings with uniformly transformed nucleic acids. We have developed a straightforward and efficient modified carbon dot (MCD)-mediated transient transformation system for delivering DNA plasmids into the seeds of wheat, which is also applicable to other plant species. This system facilitates the generation of whole seedlings that contain the transferred DNA plasmids. Furthermore, our study demonstrates that this system serves as an excellent platform for conducting functional genomic studies in wheat, including the validation of gene functions, protein interactions and regulation, omics studies, and genome editing. This advancement significantly enhances functional genomic research for any plants or crops that face challenges in stable transformation. Thus, our study provides for the first time evidence of new applications for MCDs in functional genomics and epigenomic studies, and bioengineering potentially leading to the improvement of desirable agronomic traits in crops.