Silencing of the Nonspecific Phospholipase C6 (NPC6) Gene Induces Ricinoleic Acid Accumulation in Castor Seeds

Castor, scientifically known as Ricinus communis L., is among the top ten oil crops globally. It is considered a renewable resource and is commonly referred to as 'green oil'. Castor seeds contain castor oil as their main component, which is predominantly composed of ricinoleic acid. This study utilized RNAi technology to silence the NPC6 gene in NO.2129 castor, resulting in the creation of mutant plants L1 and L2. The weight of 100 dry seed kernels from L1 and L2 exceeds that from NO.2129. The crude fat and ricinoleic acid levels of L1 and L2 were higher than those of NO.2129 at various developmental stages. In the proteomics analysis of 60-day-old castor seeds, a total of 21 differentially expressed proteins were identified, out of which 19 were successfully recognized. Eleven of the differentially expressed proteins identified were legumins, which play a crucial role in nutrient storage within the seed. Silencing the NPC6 gene results in the accumulation of ricinoleic acid in castor seeds. The findings of this study not only enhance our knowledge of NPC6's role in regulating castor seed oil synthesis but also offer fresh perspectives for investigating oil synthesis and accumulation in other plant species.