LAUSR

Assessing the effects of transgenic crops on rhizobacterial communities has catalyzed numerous studies in the recent past decades. To address further to this concern, we designed research to examine the variations in the bacterial diversity profiles of transgenic insect-resistant maize line 2A-5 (2A5) carrying mcry1Ab and mcry2Ab genes and its control Zheng58 (Z58), at different developmental stages under natural field conditions. High-throughput sequencing of the 16S rDNA gene (V3–V4) hyper-variable region via Illumina MiSeq revealed no significant shifts in the overall α and β-diversity. However, some developmental stage-dependent discrepancies were observed in the relative abundances of microbial communities. At the jointing stage, members of the phylum Proteobacteria, and the genera Rahnella, Kaistobacter, Pseudomonas and Arthrobacter were greatly enriched in the rhizosphere soil of 2A5 and Z58 compared to bulk, and surrounding soil while de-riched with the microbes belonging to the genera Bacillus and Flavobacterium. In addition, the relative abundances of nitrogen fixing microbes i.e. Arthrobacter, Burkholderia and Pseudomonas in the rhizosphere samples of 2A5 showed exuberance compared to those of Z58 at the flowering and maturation stages, implying that genetic modification might play a role in the enrichment/derichment of some nitrogen fixing microbes. The results of our study indicate little to no impacts of transgenic maize carrying mcry1Ab and mcry2Ab genes and also, the changes in the rhizosphere bacterial communities are imposed by host plant during different developmental stages.