CRISPR/Cas9 Editing of CBP80 Enhances Drought Tolerance in Potato (Solanum tuberosum)

Cecilia Decima Oneto^1,2*Gabriela A Massa¹Laura Echarte¹Maria Florencia Rey Burusco¹Matías Nicolás González³Carla Alfonso¹Maria Paula Laserna³Natalia Norero¹Silvina Divito¹Sergio Feingold¹

• ¹Instituto Nacional de Tecnología Agropecuaria (Argentina), Buenos Aires, Argentina
• ²University of Dundee, Dundee, Scotland, United Kingdom
• ³Department of Plant Breeding, Swedish University of Agricultural Sciences, SLU Alnarp, Arnalp, Sweden

The development of drought-tolerant potato varieties is becoming increasingly critical in the face of climate change and water scarcity. Potatoes are particularly sensitive to water deficits, which can significantly reduce yield and tuber quality. The cap-binding protein CBP80, known for its role in the abscisic acid (ABA) signaling pathway, has been identified as a target for improving drought tolerance in plants. In this study, we employed CRISPR/Cas9 to disrupt the CBP80 gene in the tetraploid potato cultivar Spunta.Given the complexity of editing all four alleles in a tetraploid species, eight independent lines with partial knockouts were obtained, harboring mutations in two or three alleles, but no complete (tetra-allelic) knockouts. This study focuses on the molecular and phenotypic characterization of two of these lines, which were selected based on detailed mutational analysis. Under restricted water conditions, the selected partially edited lines exhibited reduced transpiration rates, and improved leaf area index in comparison to the non-edited control. Quantitative real-time PCR revealed differential expression of drought-responsive genes (P5CS, PDH, and CBP80), with particular emphasis on the role of CBP80 in modulating stress responses. Furthermore, the edited lines displayed lower yield penalties—both in biomass and tuber production—under drought conditions.This study is among the early efforts applying genome editing to improve drought tolerance in a commercial potato cultivar. The results support the role of CBP80 in drought response and suggest its potential as a target for crop improvement. These findings provide useful insights for applying genome editing to enhance drought tolerance in potato and other crops.