Comparative and functional genomics of fibre development and natural product biosynthesis

陆地植物习性的演变最终导致了大量维管植物物种的出现，这些物种现在主导着陆地生态系统，在为人类活动提供食物、纤维和能源方面至关重要。陆地植物适应陆地环境可能需要关键的进化创新，包括出于防御、通信和结构目的的代谢途径的进化。此外，在维管陆地植物中，木质部和次生木质部(木材)中富含纤维素和木质素的次生细胞壁的形成是结构支持和养分/水分运输所必需的。这项提案的重点是模式植物(拟南芥、苔藓、杨树)和有商业价值的树木(杨树、云杉)的自然产物生物合成和纤维/次生细胞壁/木材分化和形成等关键过程的性质和调控。具体地说，我们的实验将研究新发现的编码一类潜在的天然产物的酶的基因，这些天然产物是花粉存活所需的，以及编码合成信号化合物茉莉酸的酶的基因，这是应对环境压力(如昆虫攻击)所必需的。我们还将研究调控基因，如转录因子和受体激酶，参与细胞分化为木质部和富含纤维素和木质素的纤维细胞，并研究一类定位于细胞壁的几丁质酶样蛋白，它们似乎有助于纤维素沉积到细胞壁。这项研究将提供有关植物功能的这些独特方面的基本信息，并建议如何修改这些过程，以期在植物肥力控制和抗虫害方面产生潜在的实际副产品。调节次生细胞壁形成和纤维/木质部分化的工作对于理解生物材料(纤维和木材)的形成具有重要意义，这些材料在未来几十年将作为能源和碳源变得越来越重要，并可能提出操纵和/或选择更适合生物质和/或生物燃料应用的植物和树木遗传变异的新方法。

The evolution of the land plant habit has culminated in the vast array of vascular plant species that now dominate terrestrial ecosystems and are essential in providing food, fibre, and energy for human activities. Key evolutionary innovations were likely required for the adaptation of land plants to the terrestrial environment, including evolution of metabolic pathways for defense, communication, and structural purposes. Furthermore, development of cellulose and lignin-rich secondary cell walls in xylem and secondary xylem (wood) was required in vascular land plants for structural support and nutrient/water transport. The focus of this proposal is on the nature and regulation of key processes such as natural product biosynthesis and fibre/secondary cell wall/wood differentiation and formation in model plants (Arabidopsis, moss, poplar) and commercially valuable (poplar, spruce) trees. Specifically, our experiments will investigate newly discovered genes encoding enzymes for a potentially novel class of natural products required for pollen viability and genes encoding enzymes for the biosynthesis of the signaling compound jasmonic acid, required for response to environmental stresses such as insect attack. We will also study regulatory genes such as transcription factors and receptor kinases involved in programming cells to differentiate into xylem and fibre cells rich in cellulose and lignin, and study a class of cell wall localized chitinase-like proteins that appear to facilitate cellulose deposition into cell walls. This research will provide basic information about these unique aspects of plant function and suggest how these processes might be modified, with potential practical spin-offs in plant fertility control and resistance to insect pests. The work on regulation of secondary cell wall formation and fibre/xylem differentiation has important implications for understanding the formation of biomaterials (fibre and wood) that will be increasingly important as energy and carbon sources in the coming decades and may suggest new ways to manipulate and/or select for plant and tree genetic variants that will be more amenable for biomass and/or biofuels applications.