Gathering previously published gas exchange and GC-MS data
In order to have a better understanding of the metabolic differences between ferns and angiosperms and how this influences the diel course of leaf gas exchange, we collected previous gas exchange and GC-MS data carried out in the same species studied here (Lima et al. 2019). The GC-MS data collected refer to primary metabolites detected in the same leaf samples used for LC-MS analysis. Polar metabolites were extracted according to a well-established GC-MS metabolite profiling protocol and identified using TagFinder, exactly as described previously (Lisec et al. 2006; Luedemann et al. 2008). The gas exchange was determined in leaves of angiosperms and ferns throughout the day (05:00 h, 08:00 h, 14:00 h and 17:00 h) using IRGA, as described above. We further collected data from stomatal closure kinetics induced by high CO2 or dark conditions (Lima et al. 2019) to compare the speed of stomatal closure induced by ABA, sucrose and mannitol with those observed under these environmental cues.