Peeling off the secrets of Populus trichocarpa defences

植物特化代谢物(传统上称为次生代谢物)是一类化合物，其生物合成仅限于特定的谱系，并在生态相互作用中发挥关键作用。当环境变化时，植物获得合成新的专门代谢物的能力，以此作为应对生物和非生物胁迫的一种策略。我的研究计划的长期愿景是通过探索专门代谢物的自然多样性来理解这种生化反应，弄清楚新的代谢物是如何合成的，并最终破译它们如何帮助植物在具有挑战性的环境中茁壮成长。我建议的NSERC研究计划将黑杨树(三果杨、杨树)的蜡类和萜类作为模型系统。在植物用来阻止入侵者的特征中，角质层和角质层中含有的蜡质构成了抵御恶劣环境的第一道屏障。为了研究角质层蜡质和单个蜡质成分的作用，我们将利用自然产生的毛果树的蜡质组成和丰富程度的广泛差异。我们已经证明，烯烃是一种有机化合物，是黑杨树叶蜡的主要成分。有趣的是，尽管烯烃在工业上有许多用途，但它们是如何在植物中生产的却完全不为人所知。我之前的工作确定了第一种参与烯烃生物合成的酶。这一发现为研究角质层蜡质生物合成的新途径打开了大门。然而，如果我们想要利用角质蜡多样性作为一种保护机制来抵御环境压力，仍然有几个关键领域需要调查。在拟议的研究中，我们将解决以下短期目标：1-识别和表征参与调节和产生烯烃的基因；2-调查角质蜡对环境压力的作用；以及3-开发研究萜烯所需的工具和方法，萜烯是黑杨树的另一组防御化合物。尽管推动我研究的根本问题是为什么植物会合成专门的代谢物，但产生的知识在作物改良和工业中具有潜在的应用价值。通过了解特定代谢产物的生物合成和生态作用，我们将能够培育或设计出更好地适应特定环境的植物。此外，蜡和萜烯还具有作为药品、农药、食品添加剂和生物燃料的商业价值。该项目将要求采用多学科方法，培养基因组学、生物化学、分析化学、植物生理学和生物技术方面的高素质人才。

Plant specialized metabolites (traditionally called secondary metabolites) are compounds whose biosynthesis is restricted to specific lineages and play key roles in ecological interactions. Plants acquire the ability to synthesize new specialized metabolites as a strategy to cope with biotic and abiotic stress when the environment changes. The long-term vision of my research program is to understand this biochemical response by exploring the natural diversity of specialized metabolites, figuring out how new metabolites are synthesized, and ultimately deciphering how they help the plant thrive in a challenging environment. My proposed NSERC research program focuses on waxes and terpenes from the black cottonwood tree (Populus trichocarpa, poplar) as model systems. Among the traits that plants use to deter invaders, the cuticle and the waxes contained within the cuticle constitute the first barrier against a hostile environment. To investigate the role of the cuticular waxes and individual wax components, we will exploit the extensive variation in wax composition and abundance present in a collection of naturally occurring genotypes of P. trichocarpa. We have shown that alkenes, a type of organic compound, are major components of the wax of black cottonwood leaves. Interestingly, despite the many industrial uses of alkenes, the way by which they are produced in plants was completely unknown. My previous work identified the first enzyme involved in the biosynthesis of alkenes. This discovery has opened the doors to the study of a new pathway for the biosynthesis of cuticular waxes. However, there are still several key areas that need to be investigated if we want to harness cuticular wax diversity as a protection mechanism against environmental stress. In the proposed research we will address the following short-term objectives: 1- Identify and characterize the genes involved in regulating and producing alkenes; 2- Investigate the role of cuticular waxes against environmental stresses; and 3- Develop the tools and methods required to study terpenes, another group of defence compounds of the black cottonwood tree. Even though the underlying question driving my research is why plants synthesize specialized metabolites, the knowledge generated has potential applications in crop improvement and industry. By understanding the biosynthesis and ecological role of specialized metabolites we will be able to breed or engineer plants better adapted to specific environments. Moreover, waxes and terpenes have commercial value as pharmaceuticals, pesticides, food additives, and biofuels. This program will require a multi-disciplinary approach that will train highly qualified personnel in genomics, biochemistry, analytical chemistry, plant physiology and biotechnology.