Dissected Leaf 1 encodes an MYB transcription factor that controls leaf morphology in potato

The transcription factor StDL1 regulates dissected leaf formation in potato and the genotype frequency of recessive Stdl1/Stdl1, which results in non-dissected leaves, has increased in cultivated potatoes. Leaf morphology is a key trait of plants, influencing plant architecture, photosynthetic efficiency and yield. Potato (Solanum tuberosum L.), the third most important food crop worldwide, has a diverse leaf morphology. However, despite the recent identification of several genes regulating leaf formation in other plants, few genes involved in potato leaf development have been reported. In this study, we identified an R2R3 MYB transcription factor, Dissected Leaf 1 (StDL1), regulating dissected leaf formation in potato. A naturally occurring allele of this gene, Stdl1, confers non-dissected leaves in young seedlings. Knockout of StDL1 in a diploid potato changes the leaf morphology from dissected to non-dissected. Experiments in N. benthamiana and yeast show that StDL1 is a transcriptional activator. Notably, by calculating the genotype frequency of the Stdl1/Stdl1 in 373-potato accessions, we found that it increases significantly in cultivated potatoes. This work reveals the genetic basis of dissected leaf formation in potato and provides insights into plant leaf morphology.