Crop Biotech Update

Researchers Study the Effect of Calcareous Soil on Bt Protein Expression and Efficacy in the Field

May 31, 2017

Scientists from the University of Nebraska-Lincoln and partners conducted a study to investigate if calcareous soil conditions and associated poor maize growth negatively affect the expression of Cry3Bb1. The results are published in Transgenic Research.

Expression levels of Cry3Bb1 protein were measured in plants at V5–V6 growth stage using the enzyme-linked immunosorbent assay. The researchers artificially infested Cry3Bb1 and non-Bt near isoline maize hybrids with Cry3Bb1-susceptible western corn rootworm eggs to measure survival and efficacy of Cry3Bb1 maize in calcareous and non-calcareous soils.

Results showed that there was no significant difference in expression of Cry3Bb1 protein between plants from calcareous and non-calcareous soils. It was also observed that higher survival rate of western corn rootworm in non-Bt than the Cry3Bb1 maize, which proved that Cry3Bb1 performed as expected when infested with a Cry3Bb1 susceptible rootworm population.

Based on the findings, Cry3Bb1 expression levels provide appropriate root protection against western corn rootworm regardless of soil environment, indicating that lowered Cry3Bb1 expression is not a contributing factor to the greater than expected WCR injury observed in some southwestern Nebraska maize fields.

Read the abstract in Transgenic Research.