Changes in the Potential Quantum Yield of Photosystem Ii and the Integrity of Cell Membranes Relative to the Elemental Content of the Epilithic Desert Lichen Ramalina Maciformis

Abstract

Abstract-The present study used the epilithic fruticose lichen Ramalina maciformis to investigate the occurrence of mineral elements, including heavy metals, at a distance of up to 50 km from the industrial region in Ramat Hovav in the Negev Desert, Israel. The major objective of this study was an analytical comparison of elemental content and physiological parameters of lichen vitality, apart from a test of the applicability of this specific lichen in investigations of air pollution. The Ca, Cr, Cu, K, Mg, Na, Pb, S, Sr, and Zn content of thalli from the unpolluted Tellalim site collected in August 1997, transferred to 24 biomonitoring sites, and retrieved in April 1998 was analyzed in comparison with the following parameters: The potential quantum yield of photosystem II (PSII), and the integrity of cell membranes. Transplanted thalli in several sites at Ramat Hovav accumulated large amounts of most of the elements. The K content of the transplants located in the polluted sites indicated a leakage of this element, because this content was lower than that of thalli in unpolluted sites. Calcium, Cu, Mn, and Na showed an inverse correlation with the K content of the lichen. Calcium, Cu, and Sr showed an inverse correlation with the F v /F m ratio expressing the potential quantum yield of PSII. Calcium, Cr, Cu, Mg, Na, S, and Sr showed a positive correlation with the electrical conductivity corresponding with cell-membrane disintegration. The present study demonstrated a meaningful connection between enlarged concentrations of certain elements and physiological phenomena. The capability of the lichen to detect air pollution was found to be satisfactory. The dispersion of airborne heavy metals was found, however, to be local and limited to a few hundred meters from the source of pollution.

Influence of ore processing activity on Hg, As and Sb contamination and fractionation in soils in a former mining site of Monte Amiata ore district (Italy)

“…The significant positive correlations between the concentrations of the main heavyelement contaminants in the study area (Cr, Pb, Sb and Zn) and the values of electrical conductivity in exposed lichens confirmed the hypothesis above. This is consistent with the results of other studies that found higher values of electrical conductivity in lichen transplants affected by heavy element accumulation (Adamo et al, 2003;Garty et al, 2002;Garty et al, 1998b). Paoli and Loppi (2008) also observed that cell membrane damage in E. prunastri lichens was correlated with air quality.…”

Heavy element accumulation in Evernia prunastri lichen transplants around a municipal solid waste landfill in central Italy

“…This is consistent with the results of other studies that found higher values of electrical conductivity in lichen transplants affected by heavy element accumulation (Adamo et al, 2003;Garty et al, 2002;1998b). Paoli and Loppi (2008) also observed that cell membrane damage in E. prunastri lichens was correlated with air quality.…”

Effect of dehydration on spectral reflectance and photosynthetic efficiency in Umbilicaria arctica and U. hyperborea

“…The study showed a relation between NDVI decrease and heavy metal-induced loss of photosystem (PS) II functioning expressed as a variable to maximum fluorescence ratio (F v /F m ) decrease. The F v /F m ratio decrease is caused mainly by a partial disintegration of PS II (Garty et al 2002).…”