Study on the Environmental Behavior and Ecological Effects of Exogenous Proteins from Insect-Resistant Corn in Soil

Exogenous protein degradation dynamics during transgenic maize straw degradation in soil and the mechanisms underlying soil microbial community construction remain unclear. Applying null-model analysis to determine these mechanisms is important for assessing transgenic crop straw return-to-field-related impacts on dynamic soil quality and microbial ecological function changes. A laboratory leaf degradation burial simulation was conducted to establish an exogenous protein Cry1A.401 soil degradation model and clarify its behaviors. Coupled Illumina MiSeq 16S rDNA sequencing–soil physicochemical factor analysis was used to evaluate soil microbial community characteristic and diversity changes during leaf degradation and explore soil microbial community construction mechanisms and driving factors. The results revealed that exogenous protein Cry1A.401 released from transgenic insect-resistant maize leaves exhibited consistent degradation characteristics, decreasing rapidly at the initial stage but slowly at the middle/late stages. The diversity levels within/between soil microbial community groups did not significantly differ. Coexistence was the dominant interaction type among soil microbial communities. Community assembly occurred stochastically and was limited primarily by diffusion. Insights into the putative mechanistic links among Bacillus thuringiensis (Bt) proteins, soil properties, and microorganisms are provided. Our understanding of the ecological impacts of exogenous Bt proteins released into soil via leaves on soil ecosystems was enhanced.