Cadmium exposure of heavy metal-tolerant Mesembryanthemum crystallinum L. (the common ice plant) stimulates gas exchange

et al. 2019, Śliwa-Cebula et al. 2020, 2023). In the case of cadmium, it has been shown that M. crystallinum can accumulate and deposit this metal in plant organs at relatively high levels without showing any overt signs of damage (Nosek et al. 2019, 2020, Śliwa-Cebula et al. 2020). However, the effect of the Cd ion presence on the transpiration process and photosynthetic rate in the common ice plant has not been investigated, yet. It is well known that, when analyzing plant sensitivity/ tolerance to different stresses, photosynthetic activity plays a crucial role. In considering the mechanisms of the stress response, a key question arises whether they depend on the plant’s carboxylation potential (involving RubisCO, ribulose-1,5-bisphosphate carboxylase/oxygenase or PEPC, phosphoenolpyruvate carboxylase), or on photochemical activities connected with PSI and PSII function, along with the chloroplastic electron transport chain. Thus, it is important