THE BOTANICAL REVIEW VOL. 57 JULY-SEPTEMBER, 1991 No. 3 Biochemical, Physiological, and Structural Effects of Excess Copper in Plants J. C. FERNANDES AND F. S. HENRIQUES Grupo de Disciplinas de Biologia Vegetal Faculdade de Ciencias e Tecnologia Universidade Nova de Lisboa Quinta da Torte 2825 Monte de Caparica Portugal I. Abstract ...................................................................................................................................................................... 246 I. Resum6 ....................................................................................................................................................................... 247 II. Introduction ............................................................................................................................................................ 248 III. The Role of Copper in Plants .................................................................................................................... 248 IV. Copper Concentrations in Plant Tissues ........................................................................................... 249 V. Copper Uptake, Translocation, and Accumulation in Plants ........................................... 251 VI. Effects on Plant Cell Biochemistry ........................................................................................................ 255 VII. Localization and Morphological Effects at the Cellular and Subcellular Level ... 258 VIII. Effects on Plant Physiology and Morphology ................................................................................ 259 IX. Mechanisms of Copper Tolerance in Plants ................................................................................... 262 X. Copper Complexing Compounds in Plants ..................................................................................... 264 XI. Literature Cited .................................................................................................................................................... 266 I. Abstract Heavy metal pollution is one of the most troublesome environmental problems faced by mankind nowadays. Copper, in particular, poses serious problems due to its widespread industrial and agricultural use. Unlike other heavy metals, such as cadmium, lead, and mercury, copper is not readily bioaccumulated and thus its toxicity to man and other mammals is relatively low. On the contrary, plants in general are very sensitive to Cu toxicity, displaying metabolic disturbances and growth inhibition at Cu contents in the tissues only slightly higher than the normal levels. The reduced mobility of Cu in soil and sediments, due to its strong binding to organic and inorganic colloids, constitutes, in a way, a barrier to Cu toxicity in land plants. In aqueous media, however, plants are directly exposed to the harmful effects Copies of this issue [57(3)] may be purchased from the Sci- entific Publications Department, The New York Botanical Gar- den, Bronx, NY 10458-5126 USA. Please inquire as to prices. The Botanical Review 57: 246-273, Jul.-Sep., 1991 246 9 1991 The New York Botanical Garden