
TY  - JOUR
A1  - Bidwell, Sjaan D. 
A1  - Woodrow, Ian E. 
A1  - Batianoff, George N. 
A1  - Sommer-Knudsen, Jens 
T1  - Hyperaccumulation of manganese in the rainforest tree <emph type="2">Austromyrtus bidwillii</emph> (Myrtaceae) from Queensland, Australia
JF  - Functional Plant Biology
JO  - Functional Plant Biol.
Y1  - 2002
VL  - 29
IS  - 7
SP  - 899
EP  - 905
KW  - Austromyrtus bidwillii, hyperaccumulator, manganese, organic acids, serpentine.
UR  - https://doi.org/10.1071/PP01192 
N2  - Throughout the world, over 400 species of plants are known to accumulate large quantities of metals in their shoots (`hyperaccumulators'), but of these, relatively few accumulate manganese (Mn). We have identified for the first time an Australian native hyperaccumulator of Mn, Austromyrtus bidwillii (Benth.) Burrett (Myrtaceae). Concentrations of Mn up to 19 200 &#181;g g-1 were measured in dried leaves of this rainforest tree, and young bark was found to contain up to 26 500 &#181;g g-1 Mn. Approximately 40% of the Mn in the leaves is readily extracted with water, suggesting that some of the Mn is associated with water-soluble compounds such as organic acids. Organic acids present in appreciable amounts in leaf extracts of A. bidwillii were identified and quantified by HPLC and gas chromatography-mass spectrometry. The following organic acids (in order of concentration) were present: succinic > malic &#8805; malonic > oxalic >> citric acid. The concentration of total organic acids was on average 123 000 &#181;g g-1 dry tissue, which amounted to approximately three times the molar equivalent of Mn and two times the molar equivalent of total cations (Mn, Mg and Ca), demonstrating that organic anions were in excess. The Mn remaining after water extraction ((61 &#177; 3.9&#37;) could be extracted with 0.2M HCl, suggesting that a significant portion of the Mn is associated with the cell wall (perhaps replacing Ca) or is present as other insoluble compounds. 
ER  -

