DISSERTATION RESEARCH: Metatranscriptomics links phenology with community dynamics and ecosystem function in wood decay fungi

森林含有世界上一半的陆地碳，其中大部分长期储存在林木中。这种碳通常是在树木死亡后通过真菌和其他微生物的活动释放出来的，这些微生物消耗木质碎片，分解它，并将碳释放到土壤和大气中(作为二氧化碳)。人们对木材腐烂真菌的了解大多来自对蘑菇等生殖子实体的观察，但这只是这些真菌生命周期的一个阶段。在这个项目中，将在森林生长季节和真菌的整个发育生命周期中研究真菌的活动，以测量木材腐烂活动量，并确定控制这一过程的因素。这些结果将大大提高我们对木材腐烂真菌在现在和不断变化的全球条件下释放储存的碳所起的作用的理解。这个项目将通过检查全年细胞外酶的产生，为木材腐烂真菌群落的功能提供必要的洞察力。研究人员将利用测序方法的最新进展来确定真菌何时活跃地表达衰退基因，以及衰退活动如何受到群落多样性、底物质量和环境条件的影响。高通量测序将通过捕获信使RNA群体来比较衰退基因随时间的表达，并使用核糖体RNA识别活跃真菌群落中的变化。测序数据将与胞外酶分析和呼吸测量相补充，以量化分别针对特定木材成分的酶的活性水平和释放到大气中的二氧化碳的速率。腐烂活动和真菌群落变化的驱动因素将与影响子实体生产的驱动因素进行比较。

Forests contain half of the world's terrestrial carbon, much of which is stored over long time periods in forest trees. This carbon is typically released after tree death through the actions of fungi and other microorganisms that consume woody debris, breaking it down and releasing carbon into the soil and atmosphere (as carbon dioxide). Most of what is known about wood decay fungi comes from observations of reproductive fruiting bodies, such as mushrooms, but this is only one stage of the life cycle of these fungi. In this project, fungal activities will be studied over the course of the forest growing season and over the developmental life cycle of fungi to measure the amount of wood decay activity, and to determine the factors that control the process. These results will significantly improve our understanding of the role wood decay fungi play in releasing stored carbon now and under changing global conditions. This project will provide needed insight into the functioning of wood decay fungal communities by examining the phenology of extracellular enzyme production throughout the year. The researchers will use recent advances in sequencing methods to determine when fungi are actively expressing decay genes, and how decay activity is affected by community diversity, substrate quality, and environmental conditions. High throughput sequencing will be used to compare decay gene expression through time by capturing populations of messenger RNAs, and to identify shifts in the active fungal community using ribosomal RNA. Sequencing data will be complemented with extracellular enzyme assays and measurements of respiration, to quantify the activity levels of enzymes targeting specific wood components and rate of carbon dioxide released to the atmosphere, respectively. The drivers of decay activity and fungal community changes will be compared with those affecting fruiting body production.