The data compiles different aspects of plant biology (e.g., anatomy, physiology, fitness and gene-expression) reported in scientific articles that experimentally explored the role of plant microbial symbionts in plant tolerance to chilling (0-15 degrees Celsius) and freezing (<0 degrees Celsius) conditions. Each variable included in the dataset is composed of at least four values, representing the mean of the measured variable with or without a given microbial symbiont and under control or cold conditions in a factorial design. The data were generated for a meta-analysis, and so the level of replication and standard deviation or standard error, plus other relevant information such as plant and microbial species, and source, are also included. The search from which the articles were obtained used ISI-web of Science used ENDOPH* AND COLD and MYCORRHIZA* AND COLD in both title and keyword fields from 1975 to 2019. Funding was provided by Posdoctoral-FONDECYT 3180441, FONDECYT 11140607 and the NERC-CONICYT awards (NE/P003079/1 - PII20150126)

This dataset contains plant trait measurements for nine plant functional traits (specific leaf area, vegetative height, reproductive height, seed mass, leaf dry matter content, wood density, leaf area, leaf fresh mass, leaf dry mass) collected in situ from tundra plant communities at three sites in the Yukon Territory, Canada. The three sites (Kluane Platueau (60.96 degN, 138.41 degW), Pika Camp (61.22 degN, 138.28 degW), Qikiqtaruk-Herschel Island (69.57 degN, 138.90 degW)) were visited annually from 2014-2017. Funding was provided by the NERC grant NE/M016323/1.