Evaluation of different methodology for gene editing of Clock genes (StEID1 and StLNK2) in potato (Solanum tuberosum )

Sammanfattning

Solanum tuberosum (Potato) is a cool-season, short-day crop that tuberize effectively at temperatures between 15°C-19°C and at a day length of about 12 hours. These environmental requirements pose a moderate challenge to potato cultivar in different region globally. In Northern Europe, summers are characterized by the prolonged daylight and temperature that frequently exceed 19℃. Such conditions can delay tuber initiation and stolon formation ultimately reducing number of tubers and overall yield. For farmers, potato cultivation offers a significant economic potential due to its short growth cycle and high market demand. With more than 700 million people globally lacking adequate access to enough food, improving the potato productivity and adaptability is crucial. Potato is a high yielding and nutrient rich crop, containing essential carbohydrates, amino acids, dietary fibre, vitamins, and important minerals. As a result, it is considered as a complete food, for supporting human food access and overall well-being. Optimizing potato cultivars is essential to achieve consistent high yields and meet increasing production and nutritional demands worldwide. In this thesis, we focused on the genome editing of clock-associated genes involved in photoperiod perception, specifically StEID1 and StLNK2, in the potato cultivar ‘Desirée’. The primary objective was to reprogram the plant’s circadian clock to improve its adaptation to long-day conditions, which are critical for enhancing tuberization and maximizing yield. To achieve this, we employed advanced CRISPR-Cas technologies to introduce targeted mutations. Notably, our results demonstrate the successful application of homology-directed repair (HDR) to precisely modify these genes. Furthermore, we achieved efficient and simultaneous targeting of both genes, highlighting the potential of multiplex editing strategies for complex trait improvement in potato.