ibclogo XVI International Botanical Congess

Abstract Number: 2455
Poster No. = 2042


ION INTERACTIONS IN RESPONSE TO EXCESS IRON AND MANGANESE IN THE AQUATIC PLANT, _LEMNA MINOR_


Ronald Edwards^1, _Susan Jones-Held_^1 and Michael Held^2 ^1King's College, Wilkes-Barre, PA 18711 ^2Saint Peter's College, Jersey City, NJ 07306


_Lemna minor_, has been used in toxicity assays of contaminants such as metals. Fewer studies have examined the physiological mechanism(s) of metal uptake in _Lemna_. The focus of this work was a systematic analysis of the interactions of Fe, Mn and Ca. Partitioning of metals in _Lemna_ was also examined. Calcium (10mM) reduced the adverse effects of excess Mn^+2 and/or Fe^+2 on growth in this aquatic plant. Manganese had a more pronounced effect on reducing Ca accumulation than Fe. Following treatment with iron sulfate or manganese sulfate for one week, the largest fraction of iron was oxide or oxide bound whereas Mn was present as an exchangeable or organic bound fraction. The mechanism of Fe uptake was also examined by measuring ferric reductase activity.

HTML-Version made 7. July 1999 by Kurt Stüber