title: Transgene expression and Bt protein content in transgenic Bt maize (MON810) under optimal and stressful environmental conditions.
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.
authors: ETH Zurich, IBZ, Plant Ecological Genetics, Universitaetstrasse 16, 8092 Zurich, Switzerland.
authors: Miluse
authors: M
authors: Trtikova
authors: Genok-Centre for Biosafety, 9294 Tromso, Norway.
authors: Odd Gunnar
authors: OG
authors: Wikmark
authors: ETH Zurich, IBZ, Plant Ecological Genetics, Universitaetstrasse 16, 8092 Zurich, Switzerland.
authors: Niklaus
authors: N
authors: Zemp
authors: ETH Zurich, IBZ, Plant Ecological Genetics, Universitaetstrasse 16, 8092 Zurich, Switzerland.
authors: Alex
authors: A
authors: Widmer
authors: ETH Zurich, IBZ, Plant Ecological Genetics, Universitaetstrasse 16, 8092 Zurich, Switzerland; Genok-Centre for Biosafety, 9294 Tromso, Norway.
authors: Angelika
authors: A
authors: Hilbeck
mesh_terms: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D004731:Endotoxins / Q000235:genetics* / Q000378:metabolism; D015870:Gene Expression; D018506:Gene Expression Regulation, Plant; D006460:Hemolysin Proteins / Q000235:genetics* / Q000378:metabolism; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics* / Q000378:metabolism; D013312:Stress, Physiological; D019076:Transgenes; D003313:Zea mays / Q000235:genetics* / Q000378:metabolism
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D004731:Endotoxins; D006460:Hemolysin Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis