Expression data from Zea mays cultivars Tietar and DKC 6575

Maize transgenic event MON810, grown and commercialised worldwide, is the only cultivated GM event in EU. Maize MON810, variety DKC6575, and the corresponding near-isogenic Tietar were studied in different growing conditions, to assess their behaviour in response to drought. Profiling gene expression in water deficit regimes and in generalised water stress showed an up-regulation of different stress- responsive genes. A greater number of differentially expressed genes was observed in Tietar rather than in DKC6575, with genes belonging to transcription factor families and genes encoding HSPs, LEAs and detoxification enzymes. Since these genes have been from literature, indicated as typical of stress responses, their activation in Tietar rather than in DKC6575 may be reminiscent of a more efficient water stress response. DKC6575 was also analysed for the expression of the transgene CryIAb (encoding for the delta-endotoxin insecticidal protein) in water limiting conditions. In all the experiments the CryIAb transcript was not influenced by water stress, but expressed at a constant level. This suggests that though a different pattern of sensitivity to stress, the transgenic variety maintains the same expression level for the transgene.

6

Gullì M, Salvatori E, Fusaro L, Pellacani C, Manes F, Marmiroli N