The organic air pollutant cumene hydroperoxide interferes with NOantioxidant role in rehydrating lichen

Organic pollutants effects on lichens have not been addressed. Rehydration is critical for lichens, a burst of free radicals involving NO occurs. Repeated dehydrations with organic pollutants could increase oxidative damage. Our aim is to learn the effects of cumene hydroperoxide (CP) during lichen rehydration using Ramalina farinacea (L.) Ach., its photobiont Trebouxia spp. and Asterochloris erici. Confocal imaging shows intracellular ROS and NO production within myco and phycobionts, being the chloroplast the main source of free radicals. CP increases ROS, NO and lipid peroxidation and reduces chlorophyll autofluorescence, although photosynthesis remains unaffected. Concomitant NO inhibition provokes a generalized increase of ROS and a decrease in photosynthesis. Our results suggest that CP induces a ompensatory hormetic response in Ramalina farinacea that could reduce the lichen s antioxidant resources after repeated desiccation-rehydration cycles. NO is important in the protection from CP.This project was funded by the Spanish Ministry of Education and Science [project numbers CGL2012-40058-C02-01 and CGL2009-13429-C02-01], project Prometeo 2008/174 of the Generalitat Valenciana and the project AECID PCI/A/024755/09 of the Spanish Ministry of Foreign Affaires.Catalá, M.; Gasulla Vidal, F.; Pradas Del Real, A.; García Breijo, FJ.; Reig Armiñana, J.; Barreno Rodriguez, E. (2013). The organic air pollutant cumene hydroperoxide interferes with NOantioxidant role in rehydrating lichen. Environmental Pollution. 179:277-284. https://doi.org/10.1016/j.envpol.2013.04.015S27728417