摘要:

The mechanism of zinc tolerance in non‐tolerant and tolerant clones ofDeschampsia caespitosaandAnthoxanthum odoratumhas been investigated. Analysis of non‐tolerant and tolerant clones of these two grasses showed that the tolerant roots accumulated more zinc than the non‐tolerant ones. The zinc contents of the shoots of both clones were similar and contained less zinc than the roots. Compartmental flux analysis using65Zn suggested that both clones ofD. caespitosawere capable of actively pumping zinc across the plasmalemma into the external medium. However, only the tolerant clone was capable of actively pumping zinc out of the cytoplasm of root cells into vacuoles when exposed to levels of zinc up to 1mM, this process was inhibited above 0.1mMzinc in the non‐tolerant clone. Analysis of D.caespitosafor organic acids showed that only the tolerant clone, grown in the presence of zinc accumulated high levels of malic acid. Cytoplasmic sensitivity to zinc was measured by estimating the effect of zinc upon 1‐malate and 1‐glutamate dehydrogenases extracted from roots of non‐tolerant and tolerant clones. No significant differences were found between the two clones. The implications of these observations are discussed in relationship to the mechanism of zinc tolerance in grasses.

ISSN:0190-4167    

DOI:10.1080/01904168109362872

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

The uptake of cadmium‐115 by intact seedlings of maize vas investigated with respect to time, concentration and interactions with various cations. An appreciable fraction of the cadmium absorbed by the roots was displaced by desorption and consequently constitutes the exchangeable fraction. Only a small proportion of the cadmium was absorbed in the presence of calcium indicating that this fraction is taken up predominantly by metabolically mediated processes. The transport of cadmium to the shoots was markedly reduced by the addition of zinc to the culture solution.

ISSN:0190-4167    

DOI:10.1080/01904168109362873

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

The tolerance of triticale to low copper status in a soil adjusted to extremes of pH was determined in pots in a glasshouse experiment, and compared with the tolerance of its parent species, wheat and rye. Wheat plants were extremely sensitive to copper deficiency at all soil pH values and failed to produce heads or grain, whereas rye produced maximum yield irrespective of copper status or soil pH. Intermediate tolerance of triticale was demonstrated by virtue of the copper‐pH‐genotype interaction in that triticale was tolerant like rye at pH 5.0, but sensitive at pH 8.4 like wheat.

ISSN:0190-4167    

DOI:10.1080/01904168109362874

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

It has been shown that certain plant populations have evolved tolerance to elevated amounts of trace metals in their environment. However, little attention has been given to other traits which occur in the tolerant genotype, incidental to their selected tolerances. These additional traits may be preadaptive or they may have a ‘cost’ associated, should the tolerant genotype come to occupy a new environment. This will be discussed in relation to metal tolerance and co‐tolerances, metal requirement, morphology and germination in populations of the grassDeschampsia cespitosasampled from near to a Cu/Ni smelter and from uncontaminated pastures. Comparisons have been made between the populations using tolerances to Ni, Cu, Al, Pb, Cd, Zn, and Co. These were investigated using a method adapted from Wilkins’ (1957) using relative root growth in the presence and absence of the metal in water culture [described more fully in Cox and Hutchinson (1979)].

ISSN:0190-4167    

DOI:10.1080/01904168109362875

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

ISSN:0190-4167    

DOI:10.1080/01904168109362811

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor