Functional diversity of root-associated microbial communities

在我的NSERC发现补助金中有两个项目。第一个项目调查根相关的菌根真菌的功能多样性在高山网站在碧玉国家公园，并在北极的网站在赖特山口北部边境的育空地区和西北地区。我们正试图确定实验变暖（模拟全球变暖的影响）如何影响与苔原植物根部相关的有益菌根真菌和细菌。我们正在从微生物中扩增DNA，并对其进行“DNA指纹分析”，以确定存在的真菌类型以及它们对变暖处理的反应。我们还将进行实验，研究移除和添加关键植物物种如何影响其余植物上菌根真菌的多样性和类型。第二个项目研究菌根介导的碳和氮转化的功能多样性。虽然术语“菌根”具体指真菌和植物根之间的关联，但我们知道，也有许多不同类型的细菌发生在菌根上和菌根内，可能参与碳和氮循环。这些营养循环过程最终决定了北极植物是否可以获得或限制营养。我们感兴趣的是与不同类型的菌根相关的不同活动，我们使用编码介导不同过程的关键酶的功能基因来研究它们。这些实验将提供深入了解根相关微生物群落将如何应对未来气候变化情景的见解。如果北极植物通过向根系分配更多的碳来应对变暖，并且证实与根系相关的微生物群落通过增加其生物量来应对，那么这可能是抵消气候变化影响的重要负反馈循环。

There are two projects in my NSERC Discovery Grant. The first project investigates the functional diversity of root-associated mycorrhizal fungi at an alpine site in Jasper National Park, and at an arctic site in Wright Pass on the norther border of Yukon and the NWT. We are trying to determine how experimental warming (to simulate the effects of global warming) affects the beneficial mycorrhizal fungi and bacteria associated with the roots of tundra plants. We are amplifying DNA from the microorganisms and subjecting it to "DNA fingerprinting" protocols to identify the types of fungi present and how they are responding to the warming treatments. We will also set up experiments to look at how removal and addition of key plant species affects the diversity and types of mycorrhizal fungi on the remaining plants. The second project examines the functional diversity of mycorrhiza-mediated carbon and nitrogen transformations. Although the term "mycorrhiza" specifically refers to the association between fungi and plant roots, we know that there are also many different types of bacteria occurring on and within the mycorrhizas that may be involved in carbon- and nitrogen cycling. These nutrient-cycling processes ultimately determine if nutrients will be available or limiting to arctic plants. We are interested in the different activities associated with different types of mycorrhizas, and we use functional genes that code for key enzymes that mediate the different processes as a way to study them. These experiments will provide insights into how root-associated microbial communities will respond to future climate change scenarios. If arctic plants respond to warming by allocating more carbon to their root systems, and it is confirmed that root-associated microbial communities are responding by increasing their biomass, then this could be an important negative feedback loop offsetting the effects of climate change.