PCA of sympodial inflorescence meristem (SIM) transcriptomes from multiflowered species. The maturation state of each SIM was assessed by PCA of normalized gene expression. The tomato TM and FM were included as reference stages. The analysis was restricted to TM and FM marker genes (twofold higher expression in the TM or FM than any other stage) (Methods). PC1 accounted for 55% of the variation, with the tomato TM and FM representing the minimum and maximum values, respectively. As expected, all SIMs were intermediate between the tomato TM and FM. Notably, PC1 was positively correlated with inflorescence complexity with the Spe SIM closest to the tomato TM, Sl SIM intermediate, and Spr SIM closest to the tomato FM, indicating PC1 predicts SIM maturation state and flower production potential in multiflowered species. White scale bars represent 100 µm. Reference images of SIM for S. lycopersicum and S. peruvianum adapted from Park et al. (2012).
