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The area cultivated with Bt‐cottons expressing Cry1Ac gene increases year by year in China and other countries. To evaluate any potential adverse impacts on the environment from the release of Bt (Bacillus thuringiensis) technology, the development of a method for easily detecting the activity of the Cry1Ac toxins is of particular interest. The aim of this study was to develop sandwich‐ELISA for the detection of Cry1Ac protein in Bt‐cotton tissues. A specific antibody was obtained from rabbits inoculated with Cry1Ac protein derived from Bt strain HD‐73 and a secondary antibody conjugated to HRP could combine the Bt Cry1Ac protein specifically. The limit of detection was 5 ng/mL and there were no cross‐reactions between the positive control of Cry1Ab/1Ac, Cry1C, Cry2A, Cry3Bb1 and Cry9C. Extracts of proteins from cotton leaves were used to evaluate the suitability of the assay. Tris‐borate buffer and sodium carbonate buffer were employed for the extraction of protein, the limit absorbance of detection was 0.134 and 0.449, respectively, and the latter produced a higher background. The results showed that cultivars GK‐12, GK‐22, insect‐resistant cotton, bivalent transgenic cotton and shiyuan 321 assayed positively and NON was the negative sample. The PCR method was used for the validation of the developed assay. Although both methods allowed the same results to be obtained, ELISA needed simple equipment and took less time. The developed immunoassay method is considered reliable for the detection of Bt Cry1Ac protein.

The action resonance theory (ART), a hypothesis based on a logical extension of EINSTEIN'S theory of Brownian movement, suggests that the genotype x environment interaction can be modelled as forceful encounters of the gene-products of an organism with its environment. This model has implications for molecular and cell biology, morphogenesis, evolutionary development via mutation, the mechanism of natural selection and overall function of ecosystems, extending SCHR~DINGER'S programme for molecular biology. Action, a thermodynamic property with the same physical dimensions as angular momentum and PLANCK'S quantum of action, is proposed to be reversibly generated as a result of the molecular exchange of quanta, which become resonant at equilibrium, corresponding to an optimum degree of entropy and action for living systems. Because the theory can potentially predict solutions to unsolved problems such as the folding of proteins it has strong implications for successful genetic modification of organisms and for biotechnology in general; the design of a programme of research to test this theory is proposed. A key element in this research programme, improving productivity and sustainability, would be the need to select genetically modified strains in the ecological environment or niche in which they are required to function.

The characteristics of C2H4 formation and H2 evolution associated with 2,4-D induced root structures on wheat seedlings inoculated with Azospirillum brasilense Sp7 have been investigated. C2H4 formation and H2 evolution with 2,4-D treatment is several times greater than that by wheat seedlings inoculated with Azospirillum alone, as the result of the formation of a niche for azospirilla protected from O2. This increased C2H4 production in 2,4-D treated seedlings was proportional to C2H2 concentration and it was strongly inhibited by nitrite and ammonia. The inhibition increased with greater ammonia and nitrite concentration, but was reversible. The increased rate of C2H2 reduction activity was correlated with 15N enrichment in 2,4-D treated seedlings. These results confirm that the C2H4 formation was C2H2 dependent and represented the nitrogenase activity of A. brasilense associated with the 2,4-D induced root structures of wheat seedlings rather than C2H2 produced by plant tissues.