Abstract
Melatonin is a conserved substance, which was discovered in the evolutionary distant organisms like bacteria, plants, invertebrates and vertebrates. Recent studies have shown that melatonin despite its possible role in photoperiod processes, has been found to be a direct free radical scavenger and an indirect antioxidant. In this report the impact of exogenous melatonin on the Bax inhibitor-1 (BI-1) expression level in Nicotiana tabacum L. line Bright Yellow 2 (BY-2) suspension cells exposed to lead was examined. BI-1 is a well-conserved protein in plants and animals that serves as the inhibitor of mammalian proapoptotic proteins as well as plant ROS-induced cell death. Our results showed that pretreatment with 200 nm melatonin, expressing BI-1 and fortified tobacco suspension cells against damages induced by lead. The obtained results revealed, that melatonin significantly increases BY-2 cells proliferation and protects BY-2 cells against death. Moreover, the conducted analyses showed for the first time that the protective effect of melatonin may be connected not only with its antioxidant properties but also with its direct impact on elevating BI-1 expression and lead-induced programmed cell death (PCD) restriction.
Highlights
Environment degradation caused by rapid industrial expansion e.g. mining, power generation, transport and intensive agriculture using a lot of chemicals, has become a major threat to the sustenance and welfare of mankind
Experiments were performed in the following variants: (i) C: Bright Yellow 2 (BY-2) cells cultured on LS medium; (ii) MEL: BY-2 cells cultured on LS medium with melatonin added from the beginning of culture; (iii) Pb: BY-2 cells cultured on LS medium with Pb2? added in the 4th day of culture and (iv) MEL 1 Pb: BY-2 cells cultured on LS medium with melatonin added from the start of culture and stressed with Pb2? added in the 4th day of culture
Signal transduction in programmed cell death (PCD) processes is still intensively investigated in plants
Summary
Environment degradation caused by rapid industrial expansion e.g. mining, power generation, transport and intensive agriculture using a lot of chemicals, has become a major threat to the sustenance and welfare of mankind. Pb-provoked growth inhibition and biomass reduction result from heavy metal harmful effects on various plant metabolic processes. Toxic concentrations of this metal disturb or even inhibit activities of key enzymes e.g. acid phosphatase, esterases, peroxidases, malic dehydrogenase, by reacting with their sulfhydril groups. It causes water imbalance, alterations in membrane permeability and limits mineral nutrition. Lead induce gradual glutathione depletion as a consequence of cell membrane alteration, DNA damage, gene mutation, protein oxidation, lipid peroxidation and provoke signal transduction cascade towards cell death (Wierzbicka 1999; Gill 2014)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
