Improving stress tolerance in the bioenergy crop switchgrass (Panicum virgatum) by investigating and engineering terpene metabolic networks

作为木质纤维生物燃料生产的专用下一代原料，豆科作物柳枝菊(Panicum Virgatum)具有农业经济价值。高净能量产量和广泛的栖息地范围使柳枝花适合在农业投入较少的边际土地上种植，有望实现可持续的生物燃料生产。然而，日益加剧的干旱和其他环境压力预计将成为扩大柳枝条种植的主要障碍。更深入地了解控制柳枝菊环境适应的分子机制将为优化作物生产力提供关键资源。物种特有的萜类化合物的动态网络是柳枝草非生物抗逆性的关键组成部分，通过精确的基因组工程可以利用这一知识来培育更具抗逆性的作物，并提供先进的生物燃料生产。利用基因组学支持的平台快速发现萜类代谢网络，已在柳枝草中鉴定出功能多样的大型萜类代谢基因家族。初步研究进一步证明了胁迫诱导的萜类途径的上调，支持了柳枝枝草的胁迫防御作用。利用这些结果，该项目将全基因组酶的发现与全系统组学、机制和生物活性研究相结合，以确定柳枝草萜类代谢的生物合成网络和保护作用。这种洞察力可以促进有针对性的基因组工程设计具有定制的萜烯混合物的植物，以增强弹性并从生物质原料中生产生物燃料。

The Poaceous crop switchgrass (Panicum virgatum) is of agroeconomic value as a dedicated next-generation feedstock for lignocellulosic biofuel production. High net energy yield and a wide habitat range make switchgrass suitable for cultivation on marginal lands with reduced agricultural inputs, promising sustainable biofuel production. However, rising drought and other environmental pressures are projected to become major impediments for expanded switchgrass cultivation. A deeper knowledge of the molecular mechanisms that govern switchgrass environmental adaptation would offer critical resources for optimizing crop productivity. Dynamic networks of species-specific terpenes serve as key components of switchgrass abiotic stress tolerance, knowledge of which can be harnessed through precision genome engineering to generate crops that are more resistant to stress and provide advanced biofuel production. Using a genomics-enabled platform for the rapid discovery of terpene metabolic networks, large and functionally diverse terpene-metabolic gene families have been identified in switchgrass. Preliminary studies further demonstrated stress-elicited up-regulation of terpene pathways, supporting a role in switchgrass stress defenses. Leveraging these results, this project merges genome-wide enzyme discovery with system-wide omics, mechanistic and bioactivity studies to define the biosynthetic network and protective roles of switchgrass terpene metabolism. This insight can facilitate targeted genome engineering to design plants with tailored terpene blends for enhanced resilience and biofuel production from biomass feedstock.