Fig. 1

The lace plant programmed cell death (PCD) model system. A-B Lace plant grown in axenic Magenta box culture with the pre-perforation stage (P), window stage (W), mature stage (M), and imperforate leaves (I). C Imperforate leaves emerge from the corm lacking anthocyanin and forming areoles with no perforations. D Successive pre-perforation stage leaves emerge from the corm with anthocyanin pigmentation (indicated by asterisks). E PCD can be seen actively occurring in the window stage of development. Between longitudinal and transverse veins, in spaces known as areoles, a gradient of cell death can be observed. Non-PCD cells (NPCD; bounded by white dashed lines) cells persist beyond maturity. PCD cells (bounded by black dashed lines) have lost their anthocyanins, are translucent and on the verge of death. PCD and perforation formation is complete in mature stage leaves (F) and anthocyanin pigmentation is visibly reduced, and homeostasis for NPCD cells is reached. Scale bars: A = 1 cm; B = 2 cm; C = 200 μm