Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, 86011-5640, USA.
Department of Biology, San Diego State University, San Diego, CA, 92182, USA.
New Phytol. 2019 Jan;221(1):493-502. doi: 10.1111/nph.15352. Epub 2018 Jul 16.
The interactions among climate change, plant genetic variation and fungal mutualists are poorly understood, but probably important to plant survival under drought. We examined these interactions by studying the ectomycorrhizal fungal (EMF) communities of pinyon pine seedlings (Pinus edulis) planted in a wildland ecosystem experiencing two decades of climate change-related drought. We established a common garden containing P. edulis seedlings of known maternal lineages (drought tolerant, DT; drought intolerant, DI), manipulated soil moisture and measured EMF community structure and seedling growth. Three findings emerged: EMF community composition differed at the phylum level between DT and DI seedlings, and diversity was two-fold greater in DT than in DI seedlings. EMF communities of DT seedlings did not shift with water treatment and were dominated by an ascomycete, Geopora sp. By contrast, DI seedlings shifted to basidiomycete dominance with increased moisture, demonstrating a lineage by environment interaction. DT seedlings grew larger than DI seedlings in high (28%) and low (50%) watering treatments. These results show that inherited plant traits strongly influence microbial communities, interacting with drought to affect seedling performance. These interactions and their potential feedback effects may influence the success of trees, such as P. edulis, in future climates.
气候变化、植物遗传变异和真菌共生体之间的相互作用了解甚少，但在干旱条件下对植物的生存可能很重要。我们通过研究经历了二十年与气候变化相关的干旱的野生生态系统中种植的派恩松（Pinus edulis）幼苗的外生菌根真菌（EMF）群落来研究这些相互作用。我们建立了一个包含已知母系（耐旱、DT；耐旱、DI）的派恩松幼苗的普通花园，操纵土壤水分并测量 EMF 群落结构和幼苗生长。有三个发现：DT 和 DI 幼苗之间在门水平上的 EMF 群落组成不同，DT 幼苗的多样性比 DI 幼苗高两倍。DT 幼苗的 EMF 群落不受水分处理的影响，主要由子囊菌属的一种 Geopora sp. 组成。相比之下，DI 幼苗随着水分的增加而转向担子菌的优势，表现出线粒体与环境的相互作用。在高（28%）和低（50%）浇水处理中，DT 幼苗比 DI 幼苗生长得更大。这些结果表明，植物遗传特性强烈影响微生物群落，并与干旱相互作用影响幼苗的性能。这些相互作用及其潜在的反馈效应可能会影响树木（如派恩松）在未来气候中的成功。
