Endophytic root associated fungi in the prairie: distribution and role in dryland

我们在半干旱的萨斯喀彻温省的田间草原牧草的根中发现了大量的非菌根相关真菌(RAF)。RAF可能是生活在极端环境中的植物的重要伙伴，在极端环境中，它们与丛枝菌根(AM)真菌共享根。在我们所在的草原地区，这些RAF在无症状的植物根中的丰度往往超过AM真菌，这表明在加拿大草原普遍存在的水分减少的情况下，RAF可能会对本地和农作物的生产力产生重要影响。我们实验室最近的研究表明，一些RAF可以提高植物的抗旱性，这一效果在C3和C4植物中可能有所不同。我们建议通过利用当地菌株进行温室实验，阐明RAF对本地C3和C4草原牧草耐旱性的影响，以及对主要作物物种，如小麦和豆类的影响。我们建议通过DNA分析，通过克隆和末端限制性片段长度多态性(TRFLP)的方法，来确定RAF在三个重要草原生态系统中的分布。我们将记录皇家空军在耕地中定居小麦的根，在路边种植冠状冰草，以及在草原残存生态系统中定居本地牧草的群落。我们将对在草原农业区进行的抽样活动收集的数据进行多变量分析，以确定RAF多样性分布的环境驱动因素，并确定可能的RAF-AM真菌相互作用。这项研究将为全球变化背景下的资源监测奠定基础，为生物地理学和景观生态学、微生物生态学、植物-微生物相互作用、农业生物技术发展等领域做出贡献，并对小麦生产具有重要意义。四名博士生将接受培训。

We found large amounts of non-mycorrhizal root associated fungi (RAF) in the root of field-grown prairie grasses in semiarid Saskatchewan. RAF may be important associates of plants living in extreme environments, where they share root occupation with arbuscular mycorrhizal (AM) fungi. The abundance of these RAF in asymptomatic plant roots in our region of the Prairie often exceeds that of AM fungi, suggesting that RAF may influence importantly the productivity of native and crop plants under the reduced moisture conditions prevailing in the Canadian Prairie. Recent research in our laboratory suggests that some RAF can improve plant tolerance to drought, an effect that may differ in C3 and C4 plants. We propose to clarify, through greenhouse experiments using local isolates, the effect of RAF on the drought tolerance of native C3 and C4 prairie grasses, but also on main crop species, such as wheat and pulses. We propose DNA analysis, through applications of cloning and terminal restriction fragment length polymorphism (TRFLP) methods, to define the distribution of the RAF in three important Prairie ecosystems. We will document the community of RAF colonizing the roots of wheat in cultivated fields, of crested wheatgrass in roadsides, and native grasses in prairie remnant ecosystems. We will apply multivariate analyses on data collected through sampling campaigns conducted in the agricultural regions of the Prairie, to identify the environmental drivers of RAF diversity distribution and define possible RAF-AM fungi interactions. This research will set a base line for monitoring the resource in a context of global change, and contribute to the fields of biogeography and landscape ecology, microbial ecology, plant-microbe interaction, agricultural biotechnology development, and has implication in wheat production. Four PhD students will be trained.