Transgenic Bt rice has adverse impacts on CH4 flux and rhizospheric methanogenic archaeal and methanotrophic bacterial communities

摘要

The effect of transgenic insect-resistant crops on soil microorganisms has become an issue of public concern. The goal of this study was to firstly realize the variation of in situ methane (CH4) emission flux and methanogenic and methanotrophic communities due to planting transgenic Bt rice (Bt) cultivar. CH4 emitted from paddy soil was collected by static closed chamber technique. Denaturing gradient gel electrophoresis and real-time PCR methods were employed to analyze methanogenic archaeal and methanotrophic bacterial community structure and abundance. Results showed that planting Bt rice cultivar effectively reduced in situ CH4 emission flux and methanogenic archaeal and methanotrophic bacterial community abundance and diversity. Data analysis showed that in situ CH4 emission flux increased significantly with the increase of methanogenic archaeal abundance (R (2) = 0.839, p < 0.001) and diversity index H' (R (2) = 0.729, p < 0.05), whereas was not obviously related to methanotrophic bacterial community. Our results suggested that the lower in situ CH4 emission flux from Bt soil may result from lower methanogenic archaeal community abundance and diversity, lower methanogenic activity and higher methanotrophic activity. Moreover, our results inferred that specific functional microorganisms may be a more sensitive indicator than the total archaeal, bacterial or fungal population to assess the effects of transgenic insect-resistant plants on soil microorganisms.