Only half the transcriptomic differences between resistant genetically modified and conventional rice are associated with the transgene

Abstract

SummaryBesides the intended effects that give a genetically modified (GM) plant the desired trait, unintended differences between GM and non-GM comparable plants may also occur. Profiling technologies allow their identification, and a number of examples demonstrating that unintended effects are limited and diverse have recently been reported. Both from the food safety aspect and for research purposes, it is important to discern unintended changes produced by the transgene and its expression from those that may be attributed to other factors. Here, we show differential expression of around 0.40% transcriptome between conventional rice var. Senia and Senia-afp constitutively expressing the AFP antifungal protein. Analysis of one-fifth of the regulated sequences showed that around 35% of the unintended effects could be attributed to the process used to produce GM plants, based on in vitro tissue culture techniques. A further 15% were event specific, and their regulation was attributed to host gene disruption and genome rearrangements at the insertion site, and effects on proximal sequences. Thus, only around half the transcriptional unintended effects could be associated to the transgene itself. A significant number of changes in Senia-afp and Senia are part of the plant response to stress conditions, and around half the sequences for which up-regulation was attributed to the transgene were induced in conventional (but not transgenic) plants after wounding. Unintended effects might, as such, putatively result in widening the self-resistance characteristics because of the transgene in GM plants.

Evaluation of Genetically Engineered Crops Using Transcriptomic, Proteomic, and Metabolomic Profiling Techniques

“…Rice Montero et al (2010) found around 0.40% transcriptomic differences in leaves of in vitro-grown experimental rice (Oryza sativa) lines producing an antifungal protein. They could distinguish differences due to transgene insertion (15%), transgene expression (50%), and regeneration (35%).…”

A foresight study on emerging technologies: State of the art of Omics technologies and potential applications in food and feed safety

“…Using transcriptomics, (Montero et al, 2011) compared the conventional rice var. Senia to the transgenic variant Senia-afp constitutively expressing the AFP antifungal protein.…”

“…Four studies (Batista et al, 2008;Luo et al, 2009;Montero et al, 2011;Xue et al, 2012) compared transgenic rice to wild type rice.…”

“…In other studies, omics, mainly transcriptomics, was applied on the GM vs. the non-GM plant itself, for example GM maize vs. non-GM maize (Manetti et al, 2006; or GM vs. non-GM rice (Montero et al, 2011). In general, differences between the GM and non-GM variants were detected.…”

In Vitro Culture as a Stressful Factor Triggers Changes in Polyphenols, Flavonoids and Antioxidant Activity in Somatic Hybrids between Solanum tuberosum and S. bulbocastanum and their Respective Parents

“…One of the major classes of compounds, part of the nonenzymatic antioxidant system, playing an important role in least, in the experiments focused on identifying the differences between genetically modified plants and their original counterparts, as part of the risk assessment strategy, an important percentage of the dissimilarities observed are caused by the in vitro procedure (Montero et al, 2011;Fonseca et al, 2015).…”