Decomposition of betaine aldehyde dehydrogenase transgenic maize straw and its effects on soil microbial biomass and microbiota diversity

摘要

Present study aims to explore the impact of the decomposition of betaine aldehyde dehydrogenase (BADH) transgenic maize straw on soil microbial biomass and microbiota diversity. A 210-day decomposition experiment was conducted with straws of transgenic maize BZ-136 and non-transgenic maize Zheng58 in both neutral and saline-alkali soils. The results showed that the dry weight of straw residues from transgenic maize planted in saline-alkali soil (AB) was 0.040 g less than that of straw residues from non-transgenic maize planted in salinealkali soil (AZ) at 30 d (p 0.05), but dry weight of straw residues from transgenic maize planted in neutral soil (NB) showed no difference from that of straw residues from non-transgenic maize planted in neutral soil (NZ). The decomposed cellulose amount of NB (6.39%) and AB (6.01%) was not significantly different from that of NZ and AZ (p > 0.05). At 30 d, microbial biomass carbon (MBC) of NB was 158.64 mg.kg(-1) higher than that of NZ (p < 0.05), and microbial biomass nitrogen (MBN) of AB was 10.36 mg.kg(-1) higher than that of AZ (p < 0.05). At 60 d, MBC of AB was 15.94 mg.kg(-1) higher than that of AZ (p < 0.05). The decomposition of NB and AB increased the relative abundance of Proteobacteria by 4.29% and 4.58% compared to NZ and AZ at 60 d respectively, and the decomposition of AB reduced the relative abundance of Actinobacteria by 3.82% compared to AZ at 90 d. In brief, the decomposition of BADH transgenic maize straw was accelerated in early stage, and thus temporarily increased microbial biomass and changed bacterial community in soils.