"Adaptation of Frankia, alders, and their symbiosis to environmental stress. Adaptation au stress environnemental de Frankia, des aulnes et de leur symbiose."

“Frankia、桤木及其共生对环境压力的适应。Frankia、des aulnes et de leur symbiose对环境压力的适应。”

• 批准号: 330361-2012
• 负责人: Roy, Sébastien
• 金额: $ 1.82万
• 依托单位: Université de Sherbrooke
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2013
• 资助国家: 加拿大
• 起止时间: 2013-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=527154
• 关键词: Adaptation; Frankia; alders; their; symbiosis

Filamentous actinobacteria of the genus Frankia are ubiquitous and participate significantly in global nitrogen fixation. With their host plants (actinorhizal plants, amongst which alders), they establish a root nodule symbiosis analogous to that of legumes with rhizobia. In North America, alders are of particular interest for their distribution, robustness and adaptation to a wide range of harsh environmental conditions. Although actinorhizal alders are routinely used for the revegetation of derelict lands, little research has focussed on how natural and anthropogenic stress (soil nutrient deficiency, heavy metals) affect the alder actinorhizal symbiosis. These questions are even more important considering that frankiae, in their saprophytic life cycle, are directly exposed to these stresses. Specifically, I will study: 1- cellular differentiation of growing Frankia spp. populations (i.e. massive conversion to difformed hyphae), 2- the study of interactions between alder, frankiae and ectomycorrhizal symbionts in soils that are contaminated with metals, and 3- the bacterial populations in root nodules. My research program focusses mainly on elucidating how actinorhizal alders and Frankia sp. adapt to environmental stress (both natural and anthropogenic). Through this knowledge, we are able to understand the impact of human activity on these organisms which are ubiquitous in Canada, and tailor rhizodegradation or phytoextraction technologies according to the natural potential of combinations of alder species and Frankia strains. It must be emphasized that the Frankia symbiosis (actinorhizal symbiosis) is relatively understudied. This contrasts with their importance in Nature; it is estimated that 15% to 25% of global nitrogen fixation can be attributed to these organisms. Unfortunately, the study of frankiae and their symbiosis to comprise a number of technical difficulties. I am addressing these difficulties using state-of-the-art techniques, in a systematic fashion, and pursuing this important research in an integrated manner. This results in the training of highly competent students, and in the involvement of industrial partners for the benefit of science and society.

Frankia 属的丝状放线菌无处不在，并在全球固氮过程中发挥着重要作用。它们与寄主植物（放线菌植物，其中包括桤木）建立了根瘤共生关系，类似于豆科植物与根瘤菌的共生关系。在北美，桤木因其分布、坚固性和对各种恶劣环境条件的适应能力而受到特别关注。尽管桤木放线菌通常用于废弃土地的重新植被，但很少有研究关注自然和人为胁迫（土壤养分缺乏、重金属）如何影响桤木放线菌共生。考虑到法兰克兰在其腐生生命周期中直接暴露于这些压力下，这些问题就显得更加重要。具体来说，我将研究： 1- 生长中的 Frankia spp 的细胞分化。种群（即大量转化为异型菌丝），2- 研究受金属污染的土壤中桤木、法兰克菌和外生菌根共生体之间的相互作用，3- 根瘤中的细菌种群。我的研究项目主要集中于阐明放线菌桤木和弗兰基亚属如何。适应环境压力（自然的和人为的）。通过这些知识，我们能够了解人类活动对加拿大普遍存在的这些生物的影响，并根据桤木物种和 Frankia 菌株组合的自然潜力定制根际降解或植物提取技术。必须强调的是，Frankia 共生（放线菌共生）的研究相对较少。这与它们在自然界中的重要性形成鲜明对比。据估计，全球 15% 至 25% 的固氮作用可归因于这些生物体。不幸的是，对法兰克及其共生的研究存在许多技术困难。我正在使用最先进的技术，以系统的方式解决这些困难，并以综合的方式进行这项重要的研究。这样可以培养高素质的学生，并让工业合作伙伴参与进来，造福科学和社会。