SUMMARY An important source of nutrients and raw materials for humans, seed oils also provide energy for the post‐germination growth of seeds. Hence, enhancing seed oil content is crucial to improve overall oil yield. Unsaturated fatty acids and rare neuronic acids are abundant in Yellowhorn ( Xanthoceras sorbifolium Bunge) seed oil, which is used as a cooking oil or as a raw material to make biodiesel. Nevertheless, nothing is known about the genetic controls pertaining to Yellowhorn seed oil. Here, we identified 490 single‐nucleotide polymorphism loci associated with Yellowhorn seeds. Furthermore, we identified two genes, XsLACS8 and XsMYB58 , related to seed oil, where XsMYB58 directly activated XsLACS8 to promote oil content accumulation. When transgenic soybean lines with ectopic overexpression of XsMYB58 and XsLACS8 were compared with wild‐type plants, improvements were observed in three key yield parameters: siliques per plant, seed size, and seeds per silique. In addition, transient suppression of XsMYB58 expression negatively impacted the transcription of genes linked to oil accumulation. This research sheds new light on regulatory mechanisms underlying seed oil biosynthesis. Regulating XsMYB58 activity may lead to increased oil yields in Yellowhorn and other oil‐bearing plants.
Zhang et al. (Sun,) studied this question.