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Effects of SO 2 fumigations on photosynthetic CO 2 gas exchange, chlorophyll a fluorescence emission and antioxidant enzymes in the lichens Evernia prunastri and Ramalina farinacea
Author(s) -
Deltoro V. I.,
Gimeno C.,
Calatayud A.,
Barreno E.
Publication year - 1999
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1034/j.1399-3054.1999.105408.x
Subject(s) - chlorophyll fluorescence , photosynthesis , chemistry , antioxidant , thallus , chlorophyll , thylakoid , botany , biochemistry , biology , chloroplast , gene
The effects of elevated gaseous SO 2 concentrations in the lichens Evernia prunastri (L.) Ach. and Ramalina farinacea (L.) Ach. were investigated by means of gas exchange, modulated chlorophyll fluorescence analysis and antioxidant enzyme assays. The response to SO 2 of the studied species differed markedly. Net photosynthetic rates were more adversely affected in E. prunastri than in R. farinacea . In addition, processes dependent on thylakoid membrane integrity such as PSII‐mediated electron flow and nonphotochemical quenching were reduced to a greater extent by exposure to SO 2 in E. prunastri . Moreover, the ability to reoxidize the quinone pool was lower in this species. Finally, the activity of chloroplastidic and cytoplasmic antioxidant enzymes was decreased in E. prunastri in response to fumigations but increased in R. farinacea . The results suggest that the ability to process and deal with the SO 2 once it has been absorbed must play a role in determining the sensitivity of these lichen species to this air pollutant.