The relative changes in A and gs are similar among ferns and angiosperms over the diel course
Given that stomatal movements, photosynthesis and plant metabolism all follow a circadian rhythm (Hotta 2021), we first investigated whether the the circadian rhythm of A and g s is similar between ferns and angiosperms in relative terms and which primary metabolites are clustered with these parameters throughout the diel course in both plant groups. Twelve clusters were generated according to the pattern of accumulation/degradation over the diel course by Dynamic Time Warping (DTW) analysis (Figure S1). Interestingly, both A andg s from all species were clustered together (see Cluster 11 at Figure S1). Certain sugars, organic acids and secondary metabolites were also found in this cluster. This fact notwithstanding, only glycine is common between ferns and angiosperms (Table S1). The list of metabolites found in each cluster is presented in Table S1. Angiosperms have much higher absolute values of both A andg s, but the relative changes in these parameters are identical between ferns and angiosperms throughout the diel course (Figures 1a-d). These results highlight that stomata from ferns and angiosperms have similar circadian rhythm in relative terms.