Establishing reagent testing platforms for functional analyses in sunflower

Authors: Nasti, Ryan; KENDERSKI, CATHY - University Of California Berkeley; CHANCHANI, ARYAA - University Of California Berkeley; SHARMA, AMBIKA - University Of California Berkeley; BLACKMAN, BENJAMIN - University Of California Berkeley

Submitted to: Plants
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/23/2025
Publication Date: 12/27/2025
Citation: Nasti, R.A., Kenderski, C.S., Chanchani, A., Sharma, A., Blackman, B.K. 2025. Establishing reagent testing platforms for functional analyses in sunflower. Plants. 15(1):89. https://doi.org/10.3390/plants15010089.
DOI: https://doi.org/10.3390/plants15010089

Interpretive Summary: To perform biotechnological practices, such as genetic engineering, the necessary molecular tools need to be well established and confirmed to function well in their desired context. This process is done with techniques that allow for the transient application of these components to different plant tissues or cells to test their functionality. Certain species have many well-defined methods to do these analyses, whereas others have fewer available techniques. Sunflowers are one such plant that lacks a reliable platform to test these molecular tools. We adapted three of the most common transient testing platforms to work in sunflowers and demonstrated their use by showing the function of components like observable fluorescent proteins. Establishing these techniques for future biotechnology development in sunflowers for further improvement of the important oilseed crop.

Technical Abstract: Recent advancements in molecular tools for plant genetic engineering, particularly CRISPR-based technologies, have created new opportunities for targeted genome editing. Applying these tools remains challenging however in crop species such as sunflower (Helianthus annuus) that lack of established and effective transient reagent delivery methods for functional validation. To address this gap, three major reagent delivery platforms, namely protoplast transfection, leaf infiltration, and Agrobacterium-mediated tissue co-culture, were systematically adapted and assessed for use in sunflower seedlings. While each method enabled successful reagent delivery, each manifested with differing levels of scalability and efficiency. With these platforms, comparisons were able to be made to define the most optimal components for reporter gene cassettes and related expression elements. Together, these results establish a foundational toolkit for transient functional testing in sunflower and pave the way for more sophisticated genetic engineering approaches in this agriculturally important oilseed crop.