Commonwealth Scientific and Industrial Research Organisation, Agriculture and Food, Canberra, ACT, Australia.
Department of Primary Industries, Graham Centre for Agricultural Innovation, Charles Sturt University, Wagga Wagga, NSW, Australia.
Plant Cell Physiol. 2019 May 1;60(5):945-960. doi: 10.1093/pcp/pcy247.
Cocos nucifera (coconut), a member of the Arecaceae family, is an economically important woody palm that is widely grown in tropical and subtropical regions. The coconut palm is well known for its ability to accumulate large amounts of oil, approximately 63% of the seed weight. Coconut oil varies significantly from other vegetable oils as it contains a high proportion of medium-chain fatty acids (MCFA; 85%). The unique composition of coconut oil raises interest in understanding how the coconut palm produces oil of a high saturated MCFA content, and if such an oil profile could be replicated via biotechnology interventions. Although some gene discovery work has been performed there is still a significant gap in the knowledge associated with coconut's oil production pathways. In this study, a de novo transcriptome was assembled for developing coconut endosperm to identify genes involved in the synthesis of lipids, particularly triacylglycerol. Of particular interest were thioesterases, acyltransferases and oleosins because of their involvement in the processes of releasing fatty acids for assembly, esterification of fatty acids into glycerolipids and protecting oils from degradation, respectively. It is hypothesized that some of these genes may exhibit a strong substrate preference for MCFA and hence may assist the future development of vegetable oils with an enriched MCFA composition. In this study, we identified and confirmed functionality of five candidate genes from the gene families of interest. This study will benefit future work in areas of increasing vegetable oil production and the tailoring of oil fatty acid compositions.
椰肉（椰子）是棕榈科的一员，是一种经济上重要的木本棕榈，广泛种植于热带和亚热带地区。椰子树以其积累大量油脂的能力而闻名，其种子的油脂含量约为 63%。与其他植物油相比，椰子油有很大的不同，因为它含有很高比例的中链脂肪酸（MCFA；85%）。椰子油的独特成分引起了人们的兴趣，人们想了解椰子树是如何产生高饱和 MCFA 含量的油的，如果这种油的成分可以通过生物技术干预来复制。尽管已经进行了一些基因发现工作，但与椰子油生产途径相关的知识仍存在很大差距。在这项研究中，为开发椰子胚乳组装了一个从头转录组，以鉴定参与脂质合成的基因，特别是三酰基甘油。硫酯酶、酰基转移酶和油体蛋白特别受关注，因为它们分别参与释放脂肪酸进行组装、脂肪酸酯化形成甘油酯以及保护油脂免受降解的过程。据推测，其中一些基因可能对 MCFA 表现出很强的底物偏好性，因此可能有助于未来开发富含 MCFA 的植物油。在这项研究中，我们从感兴趣的基因家族中鉴定并证实了五个候选基因的功能。这项研究将有助于未来增加植物油产量和定制油脂肪酸成分的工作。
