A rare dominant allele DYSOC1 determines seed coat color and improves seed oil content in Brassica napus

Yellow seed coat color (SCC) is a valuable trait in Brassica napus , which is significantly correlated to high seed oil content (SOC) and low seed lignocellulose content (SLC). However, no dominant yellow SCC genes were identified in B. napus . In this study, a dominant yellow SCC B. napus N53-2 was verified, and then 58,981 eQTLs and 25 trans-eQTL hotspots were identified in a double haploid population derived from N53-2 and black SCC material Ken-C8. A rare dominant allele DYSOC1 ( dominant gene of yellow seed coat color and improved seed oil content 1 ) was subsequently cloned in a trans-eQTL hotspot that colocated with SCC, SOC, and SLC QTL hotspot on ChrA09 through QTL fine mapping and multi-omics analysis. Transgenic experiments revealed that the expression of DYSOC1 produced yellow SCC seeds with significantly increased SOC and decreased SLC. Our result provides a rare dominant yellow SCC allele in B. napus , which has excellent potential for yellow SCC and high SOC rapeseed breeding.