I visited Dr. Bing Yang’s lab at University Missouri, Columbia MO, November 12 – 21, 2022. During this visit, with the help from our collaborators at Dr. Yang’s lab, I have customized a CRISPR/Cas12a-mediated genome editing system for Tragopogon (also known as goatsbeard) from the sunflower family. Tragopogon is a model system for studies of polyploidy (i.e., genome doubling), an important evolutionary force in eukaryotes. CRISPR/Cas12a is an efficient system for multiplex genome editing and gene insertion. With the established CRISPR/Cas12a system, we have expanded our toolkit for functional studies in Tragopogon. This will help us to have a better understanding of the significant evolutionary role of polyploidy from functional biology perspective.

The lab work that I have accomplished is swapping gene promoters on vectors expressing Cas12a and guide RNAs. Dr. Yang’s lab has developed a CRISPR/Cas12a system for monocot. Based on the results from our previous experiments, this monocot-customized system may not work efficiently in eudicot, including Tragopogon. Using Gibson cloning method, the maize (monocot) Ubi promoter on vector pYPQ203 (expressing Cas12a) has been changed to Ubi promoter from soybean (eudicot); the maize Ubi promoter on vector pYPQ144 (expressing guide RNAs) has been changed to Ubi promoter from Arabidopsis (eudicot). The successful construction of the vectors has been confirmed using restriction enzyme digestion.

In addition, I had many great discussions with Dr. Yang and the lab members during this visit. Some graduate students and postdocs in the lab are experienced in plant tissue culture (including soybean, hemp, Brassica, and rice). Although we have developed an efficient tissue culture and transformation system in Tragopogon, their advises will help us to improve the current systems. This will pave the way for future projects on Tragopogon, in which large quantity of transgenic plants will be generated.