Functional diversity of root-associated microbial communities

在我的国家科学研究委员会发现基金中有两个项目。第一个项目调查了贾斯珀国家公园的高山遗址和育空地区和西北地区北部边界赖特山口的北极遗址的根相关菌根真菌的功能多样性。我们正试图确定实验性变暖（模拟全球变暖的影响）如何影响与冻土带植物根部相关的有益菌根真菌和细菌。我们正在扩增微生物的DNA，并对其进行“DNA指纹”鉴定，以确定存在的真菌类型以及它们对升温处理的反应。我们还将开展实验，研究关键植物物种的移除和添加如何影响剩余植物上菌根真菌的多样性和类型。第二个项目考察了菌根介导的碳和氮转化的功能多样性。虽然“菌根”一词特指真菌和植物根之间的联系，但我们知道，菌根上和菌根内也有许多不同类型的细菌，它们可能参与碳和氮的循环。这些营养循环过程最终决定了营养物质是可用的还是仅限于北极植物。我们对与不同类型菌根相关的不同活动感兴趣，我们使用功能基因编码介导不同过程的关键酶作为研究它们的一种方式。这些实验将深入了解与根相关的微生物群落将如何应对未来的气候变化情景。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正在通过增加其生物量来应对变暖，那么这可能是一个重要的负反馈循环，抵消了气候变化的影响。

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.