Bt protein rhizosecreted from transgenic maize does not accumulate in soil

Risk Assessment and Ecological Effects of Transgenic Bacillus thuringiensis Crops on Non‐Target OrganismsF

“…Research has shown that Bt toxins can bind to clay particles and humic substances from soils, which renders the proteins resistant to biodegradation, but with retention of larvicidal activity (Zwahlen et al 2003; Clark et al 2005; Viktorov 2008; Saxena et al 2010). Most studies have suggested that Bt proteins from transgenic plants break down relatively rapidly in the early stage after entering soil, and that only a small amount of them can remain for long, so that Bt proteins do not bio‐accumulate in soil (Ahmad et al 2005; Li et al 2007; Icoz and Stotzky 2008a, 2008b; Margarit et al2008; Rauschen et al 2008; Shan et al 2008; Daudu et al 2009; Zurbrügg et al 2010).…”

Development of real time PCR assays for detection and quantification of transgene DNA of a Bacillus thuringiensis (Bt) corn hybrid in soil samples

“…No such transgene construct was carried by any plants grown in the field site before, and thus, the source of the detected transgene DNA could be contamination from the DKC42-23 plots. A few studies reported the presence of transgene DNA in non-GM fields adjacent to GM fields (Meier and Wackernagel 2003;Lerat et al 2007;Margarit et al 2008). Meier and Wackernagel (2003) detected transgene DNA in soil samples collected in the vicinity of transgenic sugar beet plots, although the study field had never before been cultivated with transgenic sugar beet.…”

Genetic Engineering and Transgenic Breeding

“…Likewise, consecutive years of planting Bt-silage maize (with the Cry1Ab insecticidal toxin) did not have negative effects on field populations of non-target soil arthropods such as Collembola and Carabidae, but crop husbandry and the environment (e.g., heavy rainfall) had the greater impact on species diversity and evenness, rather than the crop itself whether Bt or its isoline (Priestley and Brownbridge 2009). The CryIAb protein from Bt maize does not seem to accumulate at high levels in soil (Margarit et al 2008), neither affects the structure and functioning of root-associated endophyte communities (Prischl et al 2012). Farm scale evaluations of continuous cropping of transgenic herbicide tolerant maize provide little direct evidence for cumulative effects on soil-surface and above ground biodiversity (Heard et al 2006).…”