Involvement of a metallothionein-like copper complex in the mechanism of copper tolerance in Mimulus guttatus

1986 ◽  
Vol 227 (1249) ◽  
pp. 493-501 ◽  
Keyword(s):  
Copper Complex ◽  
Small Proportion ◽  
Copper Content ◽  
Copper Tolerance ◽  
Mimulus Guttatus ◽  
High Concentration ◽  
Tolerant Plants ◽  
Total Copper ◽  
Excess Copper ◽  
Copper Tolerant

The possible involvement of a metallothionein-like copper complex in the mechanism of copper tolerance in Mimulus guttatus has been examined. In the roots of copper-tolerant plants, after exposure to copper, a constant proportion of the total copper content is bound to this complex. The complex is present in the roots of both copper-tolerant and non-tolerant plants, and is also induced in the roots of both by increased exposure to copper. Differences in the amount of the complex in the roots of copper-tolerant and non-tolerant plants suggest that it may be involved in the mechanism of copper tolerance. However, only a small proportion (6%) of the copper in the roots of the copper-tolerant clone is bound to the complex after growth in a high concentration (16 μm) of copper; this result suggests that the mechanism of tolerance does not simply involve the sequestration of all excess copper by the complex. The complex may have a transient function in the mechanism of copper tolerance.

Copper tolerance in some Californian populations of the monkey flower, Mimulus guttatus

1971 ◽  
Vol 177 (1047) ◽  
pp. 177-196 ◽  
Keyword(s):  
Contaminated Soils ◽  
Preliminary Investigation ◽  
Copper Tolerance ◽  
Mimulus Guttatus ◽  
Zinc Tolerance ◽  
Low Concentrations ◽  
Lead Tolerance ◽  
Copper Mines ◽  
Normal Soil ◽  
Copper Tolerant

A preliminary investigation had been made into the evolution of copper tolerance in some Californian populations of Mimulus guttatus growing on abandoned copper mines. It has been shown that populations growing on soil with normally toxic levels of copper were tolerant to this heavy metal. There was also some indication of an increase in tolerance to zinc, lead and nickel in the copper tolerant populations, even when the soil was not particularly rich in these other metals. With one exception, populations on non-contaminated soils were non-tolerant as judged by root growth in aqueous solutions or soil containing copper. Furthermore, there was a marked difference in germination and seedling establishment on copper soil between stocks originating from mine and from non-mine environments. The superiority of the mine populations under such circumstances was less marked when established plants were potted up in mine soil. By testing the F 1 progeny of crosses involving tolerant and non-tolerant parents it was found that copper tolerance is dominant in effect at low copper concentrations, intermediate at intermediate concentrations, and recessive in effect at high copper concentrations. When the plants had been grown on normal soil there appeared to be a requirement for copper at low concentrations among the offspring of tolerant parents. It is suggested that this may result from the mechanism of tolerance by complexing the copper and thus making it unavailable to the plant. The genetic control of zinc and lead tolerance is not clear, but there is evidence that zinc tolerance may be dominant at concentrations of zinc in solution of 15 parts/10 6 .

STEROIDS IN THE SEMEN OF DOGFISH (SQUALUS ACANTHIAS)

1963 ◽  
Vol 26 (4) ◽  
pp. 489-498 ◽  
Author(s):  
T. H. SIMPSON ◽  
R. S. WRIGHT ◽  
H. GOTTFRIED
Keyword(s):  
Small Proportion ◽  
Sperm Cell ◽  
Squalus Acanthias ◽  
High Concentration ◽  
Cell Constituent

SUMMARY 11-Deoxycorticosterone has been found in surprisingly high concentration (ca. 500 μg./100 g.) in the semen of Squalus acanthias. Accompanying steroids are progesterone (8 μg./100 g.), androstenedione (2 μg./100 g.), dehydroepiandrosterone (2 μg./100 g.), pregnenolone (14 μg./100 g.), androsterone (< 5 μg./100 g.) and possibly aldosterone (< 1 μg./100 g.); three unidentified compounds were also detected. Only a small proportion (ca. 5%) of the 11-deoxycorticosterone is present in that portion of the semen which passes an ultrafilter. The remainder is either present as a sperm cell constituent or is bound to extracellular mucoids or proteins.

Quantitative Procedure for CWorophyllin Copper Complex

1994 ◽  
Vol 77 (3) ◽  
pp. 756-757 ◽  
Author(s):  
Simon Chernomorsky
Keyword(s):  
United States ◽  
Elemental Analysis ◽  
Copper Complex ◽  
Comparative Studies ◽  
Copper Content ◽  
The United States ◽  
United States Pharmacopeia ◽  
Optical Measurements ◽  
States Pharmacopeia ◽  
Quantitative Procedure

Abstract The reliability of the currently used quantitative assay for commercially available chlorophyllin copper complex is discussed. It was shown that optical measurements at 405 nm can overestimate the purity of the preparation by 16.4–49.5%. This conclusion is from comparative studies using spectrophotometry at 405 nm and elemental analysis (copper content) of chlorophyllin copper complex. Spectrophotometry at 630 nm resulted in closer agreement with data calculated from elemental analysis. These observations have to be taken into consideration by those involved in the manufacture and distribution of chlorophyllin copper complex as well as in the development of the United States Pharmacopeia compendial monograph for this preparation.

Copper requirement of a copper-tolerant isolate of Scenedesmus and the effect of copper depletion on tolerance

1981 ◽  
Vol 59 (10) ◽  
pp. 1817-1823 ◽  
Author(s):  
P. M. Stokes ◽  
S. I. Dreier
Keyword(s):  
Copper Tolerance ◽  
Complete Medium ◽  
Tolerance Mechanisms ◽  
Zinc Tolerance ◽  
Original State ◽  
High Copper ◽  
Tolerance To Cadmium ◽  
Effect Of Copper ◽  
Copper Depletion ◽  
Copper Tolerant

A copper-tolerant isolate of Scenedesmus from Sudbury, Ontario, cultured in medium completely lacking copper, lost its ability to grow at high copper concentrations after 10 generations. The change was sudden in onset and relatively rapid. The algae had previously been maintained on medium with micronutrient levels of copper and had retained their tolerance over 7 years of laboratory culture.The tolerance of the copper depleted cells to nickel and cobalt also decreased. Their tolerance to cadmium and silver was unchanged by copper depletion. The situation for zinc tolerance was less clear, but there was no significant decrease over the range tested.When copper-depleted cells were cultured in complete medium with micronutrient levels of copper, copper tolerance increased after four divisions and recovered to the original state after eight divisions. Plate assays indicated that all of the cells in the culture were recovering i.e., this was not a reselection of a few tolerant cells.The results are discussed in terms of possible tolerance mechanisms, and their implications for the occurrence of multiple or cotolerance.

scholarly journals THE GENETICS OF COPPER TOLERANCE IN THE YELLOW MONKEY FLOWER, MIMULUS GUTTATUS. I. CROSSES TO NONTOLERANTS

Genetics ◽  
1979 ◽  
Vol 91 (3) ◽  
pp. 553-563
Author(s):  
Mark R Macnair
Keyword(s):  
Threshold Model ◽  
Copper Tolerance ◽  
Additive Effects ◽  
Mimulus Guttatus ◽  
Biometrical Genetics ◽  
First Order ◽  
Monkey Flower

ABSTRACT The biometrical genetics of copper tolerance has been investigated in two Californian populations of Mimulus guttatus by crosses to a nontolerant British population. A simple biometrical model involving only additive and dominance effects is not sufficient. When the first order interactions are included, the model is shown to fit the data. Interactions between the dominance effects of different loci, and between dominance and additive effects, are the most important. These interactions can be explained either by a threshold model, or by postulating dominance modification.

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