Plant biology variables under cold stress from published experiments (1975-2019) that include microbial symbionts as an experimental factor.

After the initial selection of experimental articles that included all of the necessary data, we extracted the mean values of each variable that had been used to assess the performance of each plant species. We only used those variables for which it was also possible to estimate the level of replication and a pertinent dispersion value (i.e., standard deviation or standard error). The data were typically derived from tables and figures as reported in the published version of each article. When the figures were the only source of information, the mean and dispersion values were extracted using the online image processor WebPlotDigitizer v4.2 (https://automeris.io/WebPlotDigitizer/), which digitalizes Figures according to the given axes units, enabling the extraction of any point in the defined Cartesian space.