SummaryBiomass crops engineered to accumulate energy‐dense triacylglycerols (TAG or ‘vegetable oils’) in their vegetative tissues have emerged as potential feedstocks to meet the growing demand for renewable diesel and sustainable aviation fuel (SAF). Unlike oil palm and oilseed crops, the current commercial sources of TAG, vegetative tissues, such as leaves and stems, only transiently accumulate TAG. In this report, we used grain (Texas430 or TX430) and sugar‐accumulating ‘sweet’ (Ramada) genotypes of sorghum, a high‐yielding, environmentally resilient biomass crop, to accumulate TAG in leaves and stems. We initially tested several gene combinations for a ‘push‐pull‐protect’ strategy. The top TAG‐yielding constructs contained five oil transgenes for a sorghum WRINKLED1 transcription factor (‘push’), a Cuphea viscosissima diacylglycerol acyltransferase (DGAT; ‘pull’), a modified sesame oleosin (‘protect’) and two combinations of specialized Cuphea lysophosphatidic acid acyltransferases and medium‐chain acyl‐acyl carrier protein thioesterases. Though intended to generate oils with medium‐chain fatty acids, engineered lines accumulated oleic acid‐rich oil to amounts of up to 2.5% DW in leaves and 2.0% DW in stems in the greenhouse, 36‐fold and 49‐fold increases relative to wild‐type (WT) plants, respectively. Under field conditions, the top‐performing event accumulated TAG to amount to 5.5% DW in leaves and 3.5% DW in stems, 78‐fold and 58‐fold increases, respectively, relative to WT TX430. Transcriptomic and fluxomic analyses revealed potential bottlenecks for increased TAG accumulation. Overall, our studies highlight the utility of a lab‐to‐field pipeline coupled with systems biology studies to deliver high vegetative oil sorghum for SAF and renewable diesel production.

中文翻译：

---

营养油高粱的开发：从实验室到田间


摘要生物质作物旨在在其营养组织中积累能量密集的三酰基甘油（TAG 或“植物油”）已成为满足对可再生柴油和可持续航空燃料 （SAF） 日益增长的需求的潜在原料。与油棕和油籽作物不同，目前 TAG 的商业来源是营养组织，如叶和茎，只会短暂积累 TAG。在本报告中，我们使用了谷物（Texas430 或 TX430）和高粱（一种高产、环境适应性强的生物质作物）的积累糖分“甜”（Ramada）基因型来积累叶子和茎中的 TAG。我们最初测试了几种基因组合的 “推-拉-保护 ”策略。排名靠前的 TAG 产量构建体包含高粱WRINKLED1转录因子 （'push'）、Cuphea viscosissima 二酰甘油酰基转移酶 （DGAT;'pull'）、一种修饰的芝麻油酸 （'protect'） 和专门的 Cuphea 溶血磷脂酸酰基转移酶和中链酰基-酰基载体蛋白硫酯酶的两种组合。虽然旨在生成具有中链脂肪酸的油，但工程品系在温室中积累了富含油酸的油，在叶片中积累了高达 2.5% DW 的油，在茎中积累了高达 2.0% 的 DW，相对于野生型 （WT） 植物分别增加了 36 倍和 49 倍。在田间条件下，表现最好的事件积累的 TAG 在叶中达到 5.5% DW，在茎中达到 3.5% DW，相对于 WT TX430 分别增加了 78 倍和 58 倍。转录组学和通量组学分析揭示了 TAG 积累增加的潜在瓶颈。总体而言，我们的研究强调了实验室到田间管道与系统生物学研究相结合的实用性，用于为 SAF 和可再生柴油生产提供高营养油高粱。