PDF(Pubmed)
Abstract：
Xanthoceras sorbifolium (yellowhorn) is a woody oil plant with super stress resistance and excellent oil characteristics. The yellowhorn oil can be used as biofuel and edible oil with high nutritional and medicinal value. However, genetic studies on yellowhorn are just in the beginning, and fundamental biological questions regarding its very long-chain fatty acid (VLCFA) biosynthesis pathway remain largely unknown. In this study, we reconstructed the VLCFA biosynthesis pathway and annotated 137 genes encoding relevant enzymes. We identified four oleosin genes that package triacylglycerols (TAGs) and are specifically expressed in fruits, likely playing key roles in yellowhorn oil production. Especially, by examining time-ordered gene co-expression network (TO-GCN) constructed from fruit and leaf developments, we identified key enzymatic genes and potential regulatory transcription factors involved in VLCFA synthesis. In fruits, we further inferred a hierarchical regulatory network with MYB-related (XS03G0296800) and B3 (XS02G0057600) transcription factors as top-tier regulators, providing clues into factors controlling carbon flux into fatty acids. Our results offer new insights into key genes and transcriptional regulators governing fatty acid production in yellowhorn, laying the foundation for efforts to optimize oil content and fatty acid composition. Moreover, the gene expression patterns and putative regulatory relationships identified here will inform metabolic engineering and molecular breeding approaches tailored to meet biofuel and bioproduct demands.
摘要：
文冠果(yellowhorm)是一种具有超强抗逆性和优良油脂特性的木本油料植物。黄牛油可用作生物燃料和食用油，具有很高的营养和药用价值。然而,对Yellowhorn的遗传研究才刚刚开始，关于其超长链脂肪酸（VLCFA）生物合成途径的基本生物学问题仍然未知。在这项研究中,我们重建了VLCFA生物合成途径，并注释了137个编码相关酶的基因。我们确定了四个油质蛋白基因，它们包装三酰甘油（TAG）并在水果中特异性表达，可能在Yellowhorn石油生产中发挥关键作用。尤其是,通过检查从果实和叶片发育中构建的时序基因共表达网络（TO-GCN），我们确定了参与VLCFA合成的关键酶基因和潜在的调节转录因子。在水果中，我们进一步推断MYB相关（XS03G0296800）和B3（XS02G0057600）转录因子作为顶级调节因子的分级调节网络，为控制碳通量进入脂肪酸的因素提供线索。我们的研究结果提供了新的见解，关键基因和转录调节因子在yellowhorn控制脂肪酸的生产，为优化油脂含量和脂肪酸组成奠定基础。此外，这里确定的基因表达模式和推定的调控关系将为适应生物燃料和生物产品需求的代谢工程和分子育种方法提供信息。
