Potato (Solanum tuberosum) is the fourth most important crop in the world and widely used as food resource and industry applications as well. Sterodial glycoalkaloids (SGAs) are nitrogen-containing secondary metabolites that are derived through biosynthesis from cholesterol and form the major SGAs in potato tubers, α-solanine and α-chaconine.
Although SGAs contribute to plant resistance against pathogens and predators, their toxicity limits the amount of SGAs in food potatoes. The Swedish Food Agency recommends a maximum limit of 200 mg SGAs per kg of fresh weight of potato tubers. SGAs also become problematic in starch potatoes as they are enriched in residual products, which makes it difficult to fully utilize the industrial side stream for proteins and fibers extraction. Thus, reducing the SGA level in potato tubers is crucial for potato breeding. GAME9 is an important transcription factor (TF) that regulates the biosynthesis of SGAs and several crucial pathways in potato plants. Recent research shows that altering GAME9 expression level can significantly impact the SGA level and transcriptome changes.
Our previous results showed that we successfully generated three mutated lines targeting at GAME9 as TF, which resulted in significant reduced SGA level in leaves, and nearly zero SGA in tubers. To further investigate the function of GAME9, we conducted RNA-seq study to revel the transcriptome changes between mutants and wildtype on both leaf and tuber samples. In this RNA-seq study, we will also assess the the stress response by identifying the differentially expressed genes on tuber samples under different treatments (control, wound and light). In the end, we hope to draw a full picture of how GAME9 as TF regulates the genes and metabolites in the SGA biosynthesis pathway in potato plants.