Different Effects of Transgenic Maize and Nontransgenic Maize on Nitrogen-Transforming Archaea and Bacteria in Tropical Soils

Abstract

dThe composition of the rhizosphere microbiome is a result of interactions between plant roots, soil, and environmental conditions. The impact of genetic variation in plant species on the composition of the root-associated microbiota remains poorly understood. This study assessed the abundances and structures of nitrogen-transforming (ammonia-oxidizing) archaea and bacteria as well as nitrogen-fixing bacteria driven by genetic modification of their maize host plants. The data show that significant changes in the abundances (revealed by quantitative PCR) of ammonia-oxidizing bacterial and archaeal communities occurred as a result of the maize host being genetically modified. In contrast, the structures of the total communities (determined by PCRdenaturing gradient gel electrophoresis) were mainly driven by factors such as soil type and season and not by plant genotype. Thus, the abundances of ammonia-oxidizing bacterial and archaeal communities but not structures of those communities were revealed to be responsive to changes in maize genotype, allowing the suggestion that community abundances should be explored as candidate bioindicators for monitoring the possible impacts of cultivation of genetically modified plants.

Belowground environmental effects of transgenic crops: a soil microbial perspective

“…Other works, using culture-independent methods, reported no significant or only small effects of Bt maize plants on soil microbial communities, suggesting that plant age, soil type and texture may represent the overriding factors affecting bacterial diversity (Table 1). By contrast, different fingerprints of soil bacterial communities exposed to Bt maize were reported by other authors [23][24][25][26]. Castaldini et al [25] also observed that microbial activity, assessed by measuring soil respiration, changed in soils amended with Bt plant residues, in agreement with other reports [27,28] (Table 1).…”

Eco‐evolutionary dynamics in plant–soil feedbacks

“…(Schweitzer et al 2008;Lamit et al 2015). Agricultural research has found effects of plant genotype on the communities of bacteria and fungi in the soil, including effects of different cultivars of chickpeas (Ellouze et al 2013) and maize (Peiffer et al 2013;Cotta et al 2014;Ondreickova et al 2014).…”

High-methionine soybean has no significant effect on nitrogen-transforming bacteria in rhizosphere soil

“…Knox et al (2014) found that the GM trait is not greater than the cotton cultivar selection in generating ammonium oxidizer population and genes (nifH and amoA) involved in nitrogen transforming. In contrast, Cotta et al (2014) showed that significant changes occurred in the abundances of ammonia-oxidizing bacteria as a result of the maize host being genetically-modified. T-RFLP analyses for the nifH gene revealed bands differing between the parental and transgenic tomato lines (Ikeda et al 2006).…”