Endogenous Proteins Expression in Maize Tested in a Multi-Location Fields in India

GM crops go through multi-location field trials to analyze the agronomics, composition, and the concentration of transgenic proteins, which is a main consideration in safety assessment of GM crops. Reference proteins are expected to maintain a relatively stable expression pattern in healthy plants given their function in various cellular functions. Understanding the effects of genotype, growth stage, and location on reference proteins may provide insight into the contribution these factors could have on transgenic protein concentrations in GM crops. Thus, scientists from India, USA, and Thailand studied the concentrations of three endogenous proteins (actin, elongation factor 1-alpha, and glyceraldehyde 3-phosphate dehydrogenase) in several different maize hybrids grown across multiple field locations over two years.

The researchers collected leaf samples from healthy plants from different developmental stages across the growing seasons. Results of the enzyme-linked immunosorbent assay (ELISA) showed that the concentrations of the three  proteins were relatively consistent across hybrid backgrounds, when compared within one growth stage and location (2–26%CV), whereas the concentrations of proteins in the same hybrid and growth stage across different locations were more variable (12–64%CV). In general, the protein concentrations in the two years of study showed similar trends in variability.

According to the researchers, some degree of variability in protein concentrations was expected for both transgenic and endogenous plant-expressed proteins. In the case of GM crops, the potential variation in protein concentrations due to location effects is captured in the current model of multi-location field testing.

Read the research article in Transgenic Research.