Molecular Regulation of Bioenergy and Bioremediation in Trees

杨树（Populus sp.）生长在加拿大的每个省和地区，长期以来一直是经济的重要组成部分，因为它们在纸浆和造纸工业中的核心作用。最近，杨树正成为第二代生物燃料的重要原料，它们可以提供热量或转化为乙醇等液体燃料。采矿对加拿大经济也很重要，但在提取贵金属后留下的尾矿会造成环境成本。虽然大规模的工程努力主要用于控制大部分受污染的土壤，但总会有大量的残余污染，可能造成巨大的环境破坏。一些植物和相关真菌有能力结合这些重金属，并将它们稳定在根/真菌网络中，或者将污染物吸收到地上的生物量中。杨树根深，与包括丛枝菌根真菌在内的许多有益真菌为伍，在净化污染土壤方面具有巨大的潜力。该研究项目旨在通过识别负责这些特性的基因，更好地了解如何将杨树用于生物能源和生物修复。我们正在使用大量激活标记的杨树种群来识别控制生物能源或生物修复相关性状的基因。在安大略省金斯顿附近的一个大型野外试验中，有2000条激活标记的线，暴露在加拿大的各种天气下，生长到25英尺的高度。在过去的10年里，我的实验室对种群进行了不同表型的筛选，发现了超过75个标记系，这些标记系在木材特性、树木结构、叶片形态和害虫抗性方面发生了变化。在这个研究项目中，我们将扩大筛选范围，以识别与生物能源（木材生物量的质量和数量）和生物修复（根结构、与有益真菌相关联的能力和从土壤中吸收污染物的能力）相关的表型的标记系，并充分表征负责的基因。了解这些基因的功能将有助于未来杨树育种者选择用于生物能源或生物修复应用的树木。通过这项研究计划，至少14名HQP将在植物解剖学、生理学、分子生物学或基因组学领域接受培训，为学术界、工业界或政府工作提供宝贵的技能。

Poplars (Populus sp.) grow in every province and territory of Canada and have long been an important part of the economy because of their central role in the pulp and paper industry. More recently, poplars are emerging as an important feedstock for second generation biofuels where they can provide energy as heat or converted to liquid fuel such as ethanol. Mining is also important to the Canadian economy but there is an environmental cost when mine tailings are left behind after the precious metals have been extracted. While large-scale engineering endeavours are primarily used to contain most of the contaminated soil, there is always significant residual contamination that can cause tremendous environmental damage. Some plants and associated fungi, have the ability to bind these heavy metals and either stabilize them in the root/fungal network, or uptake the contaminates into the above ground biomass. Poplars have deep roots, associate with many beneficial fungi including arbuscular mycorrhizal fungi, and show tremendous potential for cleaning up contaminated soil. This research program seeks to better understand how poplars can be used for bioenergy and bioremediation by identifying genes that are responsible for these traits. We are using a large population of activation-tagged poplars to identify genes that control traits related to bioenergy or bioremediation. The 2000 activation-tagged lines reside in a large field trial near Kingston Ontario, are exposed to the full range of Canadian weather and grow to a height of 25 feet. For the past 10 years, my lab has screened the population for distinct phenotypes and more than 75 tagged lines with alterations in wood properties, tree structure, leaf morphology and pest resistance have been found. For this research program, we will extend the screening to identify tagged lines with phenotypes related to bioenergy (quality and quantity of wood biomass) and bioremediation (root architecture, ability to associate with beneficial fungi and uptake contaminants from the soil), and fully characterize the genes that are responsible. Understanding the function of these genes will help poplar breeders in the future select trees for bioenergy or bioremediation applications. Through this research program, at least 14 HQP will be trained in areas of plant anatomy, physiology, molecular biology or genomics, giving these trainees valuable skills for academia, industry or government jobs.