MENDEZ andrea Analia Elena
congresos y reuniones científicas
Methionine sulfoxide reductases and cadmium-induced abiotic stress: is NO an intermediary?
Congreso; SouthAmerica 11th International Congress of Plant Molecular Biology.; 2015
Proteins are macromolecules that can suffer oxidative post-translationalmodifications (MPT) induced by reactive oxygen species (ROS). An example ofthese MPT is the oxidation of the thioether moiety of methionine to the sulfoxide(MetSO). This event damages the structure and activity of proteins, but it maybe reversed by the presence of methionine sulfoxide reductases (MSR). Fivegenes for MSRA and nine for MSRB have been identified in A thaliana, coding for proteins with different subcellular locations.These sequences are associated to a higher stress tolerance and yield intransgenic plants. The present work demonstrates that MSR family is involved in the abioticstress response in plants. After treating 20 d-old Arabidopsis thaliana (Col 0) plants with 100 µM Cl2Cd for3 d, a raise in protein carbonylation, lower chlorophyll content, higher ROSlevels in chloroplasts and NO content in leaves was observed. Further analysishad shown a decrease in ascorbate (APX) and guaiacol (GPX) peroxidases, whilstcatalase (CAT) activity was higher in Cd-treated plants. This treatmentproduced a boost in transcription levels of all the MSR. Interestingly, pre-expositionof plants to 100 µM sodium nitroprusside, a NO donor, before cadmium treatment,prevented all the above mentioned. Our results indicate that the MSR family takespart in a general response pattern to oxidative stress induced by cadmium,affecting all MSR isoforms. Although NO seems to have no direct effect on theMSR transcripts levels, it may be acting as an antioxidant or as an antioxidantsystem regulator.