Effect on metal homeostasis and pollution tolerance
Lichen secondary metabolites are sensitive to heavy metal accumulation and might play a
general role in metal homeostasis and pollution tolerance. According to B
IA
Ł
ONSKA
and
D
AYAN
(2005) the levels of atranorin, physodi
c acid and hydroxyphysodic acid significantly
decreased in thalli of
Hypogymnia physodes
transplanted to the vici
nity of a chemical plant
producing chromium, phosphorous and sulfur co
mpounds. In contrast, the level of physodalic
acid increased significantly, suggesting that
this compound might be effective against
pollution stress.
Usnic acid and divaricatic acid were both found to significantly increase the intracellular
uptake of Cu
2+
in
Evernia mesomorpha
and in
Ramalina menziesii
(usnic acid only) (H
AUCK
et al. 2009), but intracellular uptake of Mn
2+
was reduced. The influence of the compounds
facilitate the survival of the two lichen species.