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Transgene expression and Bt protein content in transgenic Bt maize (MON810) under optimal and stressful environmental conditions.

Trtikova M, Wikmark OG, Zemp N, Widmer A, Hilbeck A - PLoS ONE (2015)

Bottom Line: Under stressful environmental conditions we found similar transgene expressions as under optimal conditions but Bt content responded differently.These results suggest that Bt content is not only controlled by the transgene expression but is also dependent on the genetic background of the maize variety.Under stressful conditions the concentration of Bt protein is even more difficult to predict.

View Article: PubMed Central - PubMed

Affiliation: ETH Zurich, IBZ, Plant Ecological Genetics, Universitaetstrasse 16, 8092 Zurich, Switzerland.

ABSTRACT
Bt protein content in transgenic insect resistant (Bt) maize may vary between tissues within plants and between plants growing under different environmental conditions. However, it is unknown whether and how Bt protein content correlates with transgene expression, and whether this relationship is influenced by stressful environmental conditions. Two Bt maize varieties containing the same transgene cassette (MON 810) were grown under optimal and stressful conditions. Before and during stress exposure, the upper leaves were analysed for transgene expression using quantitative RT-PCR and for Bt content using ELISA. Under optimal conditions there was no significant difference in the transgene expression between the two investigated Bt maize varieties whereas Bt protein content differed significantly. Transgene expression was correlated with Bt protein content in only one of the varieties. Under stressful environmental conditions we found similar transgene expressions as under optimal conditions but Bt content responded differently. These results suggest that Bt content is not only controlled by the transgene expression but is also dependent on the genetic background of the maize variety. Under stressful conditions the concentration of Bt protein is even more difficult to predict.

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Related in: MedlinePlus

Transgene expression.Fold change in the transgene expression in the upper leaves of the white and yellow Bt maize between the first (before stress) and the second (during stress) sampling. Calculated as the ratio of the ‘during stress’ value to the ‘before stress’ value (i.e. 1 = no change). Plants grown under optimal growth conditions were exposed to no stress. The means labelled with the different letters are significantly different at P < 0.05, Tukey’s HSD. Means ± SE, n = 5.
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pone.0123011.g001: Transgene expression.Fold change in the transgene expression in the upper leaves of the white and yellow Bt maize between the first (before stress) and the second (during stress) sampling. Calculated as the ratio of the ‘during stress’ value to the ‘before stress’ value (i.e. 1 = no change). Plants grown under optimal growth conditions were exposed to no stress. The means labelled with the different letters are significantly different at P < 0.05, Tukey’s HSD. Means ± SE, n = 5.

Mentions: There was no significant difference in cry1Ab expression in the upper leaves of the two Bt maize varieties (Table 1). Also, the transgene expression did not differ between the treatments (Table 1). We also compared how transgene expression changed during the stress relative to the level before stress (i.e. fold change) in the same plants (Fig 1). In the white Bt maize, the transgene expression under cold/wet stress was similar to the expression under optimal conditions, but was significantly reduced under hot/dry stress. In the yellow Bt maize, the transgene expression under cold/wet and hot/dry stress was not significantly different from the expression under optimal conditions (Fig 1).


Transgene expression and Bt protein content in transgenic Bt maize (MON810) under optimal and stressful environmental conditions.

Trtikova M, Wikmark OG, Zemp N, Widmer A, Hilbeck A - PLoS ONE (2015)

Transgene expression.Fold change in the transgene expression in the upper leaves of the white and yellow Bt maize between the first (before stress) and the second (during stress) sampling. Calculated as the ratio of the ‘during stress’ value to the ‘before stress’ value (i.e. 1 = no change). Plants grown under optimal growth conditions were exposed to no stress. The means labelled with the different letters are significantly different at P < 0.05, Tukey’s HSD. Means ± SE, n = 5.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4390241&req=5

pone.0123011.g001: Transgene expression.Fold change in the transgene expression in the upper leaves of the white and yellow Bt maize between the first (before stress) and the second (during stress) sampling. Calculated as the ratio of the ‘during stress’ value to the ‘before stress’ value (i.e. 1 = no change). Plants grown under optimal growth conditions were exposed to no stress. The means labelled with the different letters are significantly different at P < 0.05, Tukey’s HSD. Means ± SE, n = 5.
Mentions: There was no significant difference in cry1Ab expression in the upper leaves of the two Bt maize varieties (Table 1). Also, the transgene expression did not differ between the treatments (Table 1). We also compared how transgene expression changed during the stress relative to the level before stress (i.e. fold change) in the same plants (Fig 1). In the white Bt maize, the transgene expression under cold/wet stress was similar to the expression under optimal conditions, but was significantly reduced under hot/dry stress. In the yellow Bt maize, the transgene expression under cold/wet and hot/dry stress was not significantly different from the expression under optimal conditions (Fig 1).

Bottom Line: Under stressful environmental conditions we found similar transgene expressions as under optimal conditions but Bt content responded differently.These results suggest that Bt content is not only controlled by the transgene expression but is also dependent on the genetic background of the maize variety.Under stressful conditions the concentration of Bt protein is even more difficult to predict.

View Article: PubMed Central - PubMed

Affiliation: ETH Zurich, IBZ, Plant Ecological Genetics, Universitaetstrasse 16, 8092 Zurich, Switzerland.

ABSTRACT
Bt protein content in transgenic insect resistant (Bt) maize may vary between tissues within plants and between plants growing under different environmental conditions. However, it is unknown whether and how Bt protein content correlates with transgene expression, and whether this relationship is influenced by stressful environmental conditions. Two Bt maize varieties containing the same transgene cassette (MON 810) were grown under optimal and stressful conditions. Before and during stress exposure, the upper leaves were analysed for transgene expression using quantitative RT-PCR and for Bt content using ELISA. Under optimal conditions there was no significant difference in the transgene expression between the two investigated Bt maize varieties whereas Bt protein content differed significantly. Transgene expression was correlated with Bt protein content in only one of the varieties. Under stressful environmental conditions we found similar transgene expressions as under optimal conditions but Bt content responded differently. These results suggest that Bt content is not only controlled by the transgene expression but is also dependent on the genetic background of the maize variety. Under stressful conditions the concentration of Bt protein is even more difficult to predict.

No MeSH data available.


Related in: MedlinePlus