COPPER-BINDING PROTEIN AND COPPER TOLERANCE IN AGROSTIS-GIGANTEA

Cu-binding protein was measured in roots of a Cu-tolerant and 2 nontolerant ecotypes of A. gigantea. Cu-binding protein was present in all 3 ecotypes and was induced to increase by application of Cu. In the Cu-tolerant ecotype Cu-binding protein increased within 1 day of growing the plants in various concentrations of excess Cu. These roots continued to elongate. Under the same conditions the roots of the non-tolerant ecotypes grew little and their Cu-binding protein contents rose only after 2 or 3 days. The rapid production of Cu-binding protein is essential for the expression of Cu-tolerance in A. gigantea.