Unintended changes in protein expression revealed by proteomic analysis of seeds from transgenic pea expressing a bean α‐amylase inhibitor gene

Abstract

Seeds of genetically modified (GM) peas (Pisum sativum L.) expressing the gene for alpha-amylase inhibitor-1 (alphaAI1) from the common bean (Phaseolus vulgaris L. cv. Tendergreen) exhibit resistance to the pea weevil (Bruchus pisorum). A proteomic analysis was carried out to compare seeds from GM pea lines expressing the bean alphaAI1 protein and the corresponding alphaAI1-free segregating lines and non-GM parental line to identify unintended alterations to the proteome of GM peas due to the introduction of the gene for alphaAI1. Proteomic analysis showed that in addition to the presence of alphaAI1, 33 other proteins were differentially accumulated in the alphaAI1-expressing GM lines compared with their non-GM parental line and these were grouped into five expression classes. Among these 33 proteins, only three were found to be associated with the expression of alphaAI1 in the GM pea lines. The accumulation of the remaining 30 proteins appears to be associated with Agrobacterium-mediated transformation events. Sixteen proteins were identified after MALDI-TOF-TOF analysis. About 56% of the identified proteins with altered accumulation in the GM pea were storage proteins including legumin, vicilin or convicilin, phaseolin, cupin and valosin-containing protein. Two proteins were uniquely expressed in the alphaAI1-expressing GM lines and one new protein was present in both the alphaAI1-expressing GM lines and their alphaAI1-free segregating lines, suggesting that both transgenesis and transformation events led to demonstrable changes in the proteomes of the GM lines tested.

Inactivation of allergens and toxins

“…A similar situation was found for transgenic peas expressing the bean a-amylase inhibitor [104]. The transgenic peas elicited an immune response in mice upon feeding, but the reaction could be ascribed to changes induced in the plant by the transformation and regeneration procedure or by the changes detected in the a-amylase inhibitor between bean and pea [105] regarding the glycosylation pattern and the removal of amino acid residues of the protein. The guidance rules adopted in the EU require a risk analysis for potential allergenicity for any gene that is being used for transformation [106,107].…”

A bifunctional α-amylase/trypsin inhibitor from pigeonpea seeds: Purification, biochemical characterization and its bio-efficacy against Helicoverpa armigera

“…10 defined as per Chen et al [26]. The MULTALIN program [27] was used to align the homologous α-AI sequences obtained after NCBI BLAST of matched internal peptide sequences.…”

Proteomic evaluation of genetically modified crops: current status and challenges

“…Some studies investigated different varieties for detecting natural variation. Proteomic evaluation of a GM pea cultivar carrying α-amylase inhibitor-1 (αAI1) was discussed elsewhere (Chen et al, 2009; Islam et al, 2009; Ricroch et al, 2011). An excellent review discussed MS-based identification of transgenic proteins in GM crops (Garcia-Canas et al, 2011).…”