Environmental stress, genetic

The techniques of molecular biology have particular potential for rapidly introducing small numbers of single genes. Unfortunately there is strong evidence that the complex compensation mechanisms that exist in plants, and the interactions between different whole-plant and biochemical responses to stress, will make the direct improvement of environmental stress tolerance in crop plants by genetic engineering rather more difficult... 

The use of protoplasts in studies of stress physiology and biochemistry expands the advantages of cell culture systems discussed in the preceding sections. Additional applications are related to the fusion of protoplasts. Intraspecifie and interspecific protoplast fusion greatly enhance genetic variability of the fused protoplasts (Kumar Cocking, 1987). The resulting somatic hybrids provide cells which can be used for selection of specific traits (e.g. environmental stress tolerance) provided by one or both donor cells and for basic studies on cytoplasmic and nuclear inheritance of desired characteristics. 

While genetic studies provide clear evidence that a substantial proportion of the variation in risk for developing a substance abuse or dependence disorder is accounted for by genetic variation, these studies also point to a significant environmental contribution. Although environmental determinants of risk for substance abuse or dependence are undoubtedly complex, recent work has indicated that environmental stress can... 

Verkleij, J. A. C., Lolkema, P. C., de Neeling, A.L. Harmens, H. (1991). Heavy metal resistance in higher plants biochemical and genetic aspects. In Ecological Responses to Environmental Stresses, ed. J. Rozema J. A. C. Verkleij, pp. 8-19. London Kluwer Academic. 

We wish to thank Drs W. Taylor (CSIRO) and T. Nelson (Yale) for providing MOD and MDH gene probes. Supported by USDA-CRGP (Environmental Stress Program), USDA-CRSR (SW Consortium on Plant Genetics) and, in part, the National Science Foundation. We are indebted to Dr John L. Wray for suggestions that improved the manuscript. 

Like many traits, concentrations of secondary metabolites in algae are determined by a combination of genetic and environmental factors. Secondary metabolites are known to respond to changes in a variety of environmental conditions, including light,14,49,70 herbivory,43" 6, nutrients,44,45,49,73,74 desiccation,75 and salinity.76 Most of these studies have looked at the effects of a single environmental stress at once. However, in nature, multiple stresses often occur simultaneously and may have synergistic effects. 

Hoffmann AA, Parsons PA. 1991. Evolutionary genetics and environmental stress. Oxford (UK) Oxford Science Publishers, 296 p. 

Advances in Modifications of Biochemical Properties of Cereal Allergens The Effect of Environmental Stresses on Allergic Properties of Cereal Proteins and the Problem of Safety of Genetically... 

ADVANCES IN MODIFICATIONS OF BIOCHEMICAL PROPERTIES OF CEREAL ALLERGENS THE EFFECT OF ENVIRONMENTAL STRESSES ON ALLERGIC PROPERTIES OF CEREAL PROTEINS AND THE PROBLEM OF SAFETY OF GENETICALLY MODIFIED CEREALS... 

For example, if genetic variation exists in a crop plant population, it will become apparent under the environmental stress of a siege of pollution. Some individuals will survive the attack with no or minimum... 

Air quality standards have to take into account the seasonal fluctuation of tolerance. The level below which no effect will be seen on Norway spruce under field conditions is, however, much lower than that found in this fumigation experiment. The observed differences between graftings and seedlings and between both progenies (see Fig. 2) require greater numbers of replication for verification and interpretation because environmental stress and genetic disposition have to be separated from each other. 

Another effect of genetic uniformity is to make the entire population of plants also vulnerable to the same environmental stresses. 

Possible health benefits of consuming fish oils and omega-3 fatty acids have been reviewed by various authors (1-5). These oils can also be obtained from phytoplankton (6-8). Oils obtained from phytoplankton do not contain cholesterol. Phytoplankton require very simple nutrients in easy-to-maintain growth conditions. They can be harvested in short culture cycles. They can be manipulated by genetic engineering to increase their yield and their resistance to environmental stresses. 

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