Localization of Heavy Metals and Other Elements Accumulated in the Lichen Thallus

Abstract

SUMMARYThis study demonstrates the extracellular deposition of particulate metallic fall-out accumulated in the lichen Caloptaca aiirantia with the aid of scanning and transmission electron microscopy and the application of energy dispersive X-ray analyses. The elemental composition of particles integrated in the lichen tissue was compared with the elemental composition of dust partieles collected from the surface of the lichen colonies.The different effect of heavy metals in particulate form or in solution, as reflected by lichen's tolerance or sensitivity, is discussed.

Accumulation du plomb par les lichens

“…Ainsi, pour Brown (1976), le plomb a une localisation intracellulaire tandis que pour Goyal et , puis Tyler (1989), il s'agit d'une localisation extracellulaire. Un argument déter-minant en faveur d'une localisation extracellulaire a été apporté par Garty et al (1979) qui ont observé, au microscope électronique à balayage, la présence de particules de métaux lourds dans les larges espaces extracellulaires de la médulle. Chez Hypogymnia physodes, la forte rétention de plomb indique une liaison particulièrement effi.-:ace du plomb, qui laisse penser à une localisation à la fois intracellulaire ct extracellulaire.…”

Impact of Heavy Metals on Water Loss from Lichen Thalli

“…This must be one of the reasons for the diminished water loss in 10 −8 and 10 −6 M Zn-treated C. rangiformis. Intracellular uptake of supplied Zn (Wainwright and Beckett, 1975;Brown, 1976;Garty et al, 1979;Chettri et al, 1996) must be one of the reasons for the rapid water loss in Cladonia.…”

Air Pollution Monitoring in the south-east baltic using the epiphytic lichen <em>h</em><em>ypogymnia physodes</em>

“…However, this assumption has been questioned in some works [10][11][12][13]. The sources of heavy metals, the mechanisms of heavy metal accumulation and detoxification by lichens, and lichen's bioaccumulation capacity have been discussed in a number of works [14][15][16][17][18][19][20]. The biochemical composition, physiological processes, anatomical and morphological characteristics, population structure, species composition, and structure of lichen communities change under the influence of pollutants.…”