Terpenoid Defences in Spruce (Picea spp.)

云杉是加拿大森林工业中最重要的经济树种之一；它们在加拿大的许多森林生态系统中占主导地位，对亚洲和欧洲的森林经济也至关重要。随着环境的变化，云杉和其他针叶树越来越多地受到虫害和病原体爆发的挑战。可持续森林管理需要对树木的自然防御和抵抗机制有深入的了解。在与害虫和病原体数亿年的共同进化中，针叶树进化出了一种称为油树脂（沥青）的主要化学防御系统。油树脂是一种复杂的混合物，由数百种特殊的代谢物（萜类）在树脂管或水泡中形成。它主要由二萜树脂酸（松香）和挥发性单萜（松节油）组成。油脂树脂的化学多样性是由萜烯合成酶和细胞色素p450等基因和酶产生的。针叶树积累油树脂作为预先形成的或昆虫/病原体诱导的防御。油树脂和其他化学物质为针叶树提供持久的保护，使其免受大多数潜在害虫或病原体的侵害。虽然一些极具破坏性的害虫（如象鼻虫、树皮甲虫、budworm）可以压倒或破坏树木的防御，但即使在这些系统中，也观察到树木的独特抵抗力。例如，在特定基因型的锡特卡云杉中发现了对象鼻虫的抗性。我对云杉抵御象鼻虫的长期研究项目建立了一个基于基因组学的油树脂/萜类防御分子表征的野外定义系统。我的项目提供了关于自然树木防御机制的领先知识，这些知识正在与加拿大和国际森林管理组织合作应用，以实现经济和生态效益。除了林业，萜类化合物在许多生物产品工业（食品、香精、香料、生物农药、制药）和先进的生物燃料中也具有巨大的价值。我的萜类生物化学项目为这些行业的应用提供了先进的知识和技术。我的项目为本科生、研究生、博士后和技术人员提供了良好的培训机会。

Species of spruce are among the most economically important trees for Canada's forest industry; they dominate many of the forest ecosystems across Canada, and are also of critical importance to forest economies in Asia and Europe. With environmental change, spruce and other conifers are increasingly challenged by outbreaks of insect pests and pathogens. Sustainable forest management requires advanced knowledge of trees' natural defence and resistance mechanisms. In hundreds of millions of years of co-evolution with pests and pathogens, conifers have evolved major chemical defences known as oleoresin (pitch). Oleoresin is a complex mixture of hundreds of specialized metabolites (terpenoids) formed in resin ducts or blisters. It consists mostly of diterpene resin acids (rosin) and volatile monoterpenes (turpentine). The chemical diversity of oleoresin is produced by genes and enzymes known as terpene synthases and cytochrome P450s. Conifers accumulate oleoresin as preformed or insect/pathogen-induced defences. Oleoresin and other chemicals provide durable protection for conifers against most potential pests or pathogens. While some highly destructive pests (e.g., weevils, bark beetles, budworms) can overwhelm or undermine tree defences, even in these systems unique tree resistance has been observed. For example, resistance against weevils was identified in select genotypes of Sitka spruce. My long-term research program on spruce defence against weevils established a field-defining system for a genomics-enabled, molecular characterization of oleoresin/terpenoid defences. My program delivers leading knowledge on natural tree defence mechanisms, which is being applied in collaboration with Canadian and international forest stewardship organizations for economic and ecological benefits. Beyond forestry, terpenoids are also enormously valuable for many bio-product industries (food, flavour, fragrance, bio-pesticides, pharmaceuticals) and as advanced biofuels. My program on terpenoid biochemistry delivers advanced knowledge and technology for applications in these industries. My program provides excellent training opportunities for undergraduate and graduate students, postdoctoral trainees, and technicians.