The stability of the Arabidopsis transcriptome in transgenic plants expressing the marker genes nptII and uidA

Abstract

SummaryThe ATH1 Arabidopsis GeneChip from Affymetrix was used to search for transcriptome changes in Arabidopsis associated with the strong expression of transgenes regulated by constitutive promoters. The insertion and expression of the commonly used marker genes, uidA and nptII, did not induce changes to the expression patterns of the approximately 24 000 genes that were screened under optimal growth conditions and under physiological stress imposed by low temperatures. Approximately 8000 genes (35% of the Arabidopsis genome) underwent changes in gene expression in both wild-type and transgenic plants under abiotic stresses such as salt, dehydration, cold, and heat. This study provides detailed information on the extent of nontargeted or pleiotropic effects of transgenes on plants and shows that the transgenic and non-transgenic plants were equivalent in their global patterns of transcription. This information may help to extend our understanding and interpretation of the principle of substantial equivalence which is used as a first step in the biosafety evaluation of transgenic crops.

The pleiotropic effects of thebargene and glufosinate on theArabidopsistranscriptome

“…An understanding of the unintended effects of genes (Cellini et al ., 2004) and drought (El Ouakfaoui and Miki, 2005). These data show that transgenic plants created with these marker genes are transcriptionally identical to non-transgenic plants.…”

Biosafety considerations for selectable and scorable markers used in cassava (Manihot esculentaCrantz) biotechnology

“…Toxic effects are not expected from metabolites of transgenic GUS activity in plants (Gilissen et al, 1998). As with nptII, Ouakfaoui and Miki (2005) reported no phenotypic or genetic expression changes of 24,000 genes in transgenic Arabidopsis plants containing the uidA gene. Potential risks of horizontal gene transfer: As with the other markers, genes originally isolated from E. coli (nptII, hph and manA), the uidA gene and the GUS enzyme are widely distributed in the environment, are present in the intestinal tract of vertebrates, including man and are present in food.…”

“…In 2004, the Scientific Panel on genetically modified organisms (GMO Panel) of the European Food Safety Authority (EFSA) concluded that after 13 years of safe use and careful evaluation, there is no rationale for restricting the use of nptII as a selectable marker for either field studies or commercialization of crop plants containing the protein (European Food Safety Authority, 2004). Pleiotropic effects: Enhancement of physiological fitness due to pleiotropic effects of nptII has not been documented (Miki and McHugh, 2004), and expression of nptII in Arabidopsis had no functional effect on the expression of 24,000 other genes studied (Ouakfaoui and Miki, 2005).…”

“…These pleiotropic effects may alter the fitness, environmental impact, or food and feed safety characteristics of the organism. Using GeneChip technology, Ouakfaoui and Miki (2005) (Cellini et al, 2004). HGT between the transformed plants and soil microflora, gut bacteria or cells of organisms ingesting the plants may allow the recipient cell or organism to express a protein with unintentional effects (Van den Eede et al, 2004).…”

Genetic Engineering and Sustainable Crop Disease Management: Opportunities for Case-by-Case Decision-Making

“…To my knowledge, there is no published, validated research showing any fundamental biochemical or biophysical difference between DNA recombined in a test tube vs. that recombined in a living cell. (2) Compared to other breeding techniques, targeted DNA manipulations achieved during transgenesis, cisgenesis, intragenesis, or genome editing are no more disruptive-and are commonly less disruptive-to a plant's genome, transcriptome, proteome, and composition than other methods of crop improvement [170,171,[195][196][197][198][199][200]. If unanticipated health consequences from GE manipulations merit concern, so do the unanticipated health consequences of each new conventionally bred crop variety [201].…”