Effects of Bt Proteins from Corn Straw on Enzyme Activities of Redworms

Bacillus thuringiensis (Bt ) proteins produced from Bt corn may enter the soil ecosystem when straw from Bt corn is returned to the field, when roots release substances on the soil, or when pollen falls on the ground. Shu Ying-hua from South China Agricultural University and colleagues conducted a study to investigate the effects of Bt proteins from Bt corn straw on the soil ecosystem, particularly in the enzyme activities of redworm (Eisenia fetida).

The researchers added straws from Bt corn and its non-trangenic counterparts on the soil with an application rate of 5% and 7.5% and allowed breeding of redworms on the soil. The total Bt protein content and the activities of enzymes acetylcholine esterase (AchE), glutathione peroxidase (GSH-PX), catalase (CAT), and superoxide dismutase (SOD) in redworm were recorded after 7 and 14 days.

Results showed that the total protein content and the GSH-PX activity decreased while the AchE, CAT, and SOD activities increased on the 14th day, compared with those on the 7th day. In soils with Bt corn straw, there was an increase in the SOD activity and decrease in AchE and GSH-PX activities but had less effects on the total protein content and CAT activity, compared with non-Bt corn straw. Thus, Bt corn straw had no inhibitory impact on the total protein of redworms but may have some effect on the activity of some enzymes.

Read the abstract at http://www.cjae.net/EN/Y2011/V22/I08/2133.