| The safety of transgenic crops has attracted worldwide concern with increasing commercialization of Genetically Modified Crops (GMCs). Our study investagated the impact of this transgenic maize on soil microbial community structure in four different stages, including before the planting, the jointing stage, silking and maturity stages) based on phyAo transgenic maize and receptor control maize, using DGGE and PLFA. Aimed to assess the impact of this transgenic maize on soil ecological functions in these four stages, the soil physical and chemical properties and activity of main soil enzyme were measured.These results indicated that:The phyAo transgenic maize significantly decreased the number of phosphate-solubilizing bacteria in silking stage compared with receptor control, however, there was no significant difference on species of phosphate-solubilizing bacteria and activities of phosphate-solubilizing during the four stages.The results of DGGE map and Cluster analysis showed no obvious difference on soil microbial community structure between phyAo transgenic maize and receptor control maize, and the dominant bacterial genus in rhizosphere soil were stable across the four investagate stages. In addition, the results of PLFA indicated that phyAo transgenic maize and receptor control maize had non-significant difference on total PLFAs and fungal PLFAs in each stage, however, the concent of bacterial PLFA in rhizosphere soil significantly increased in phyAo transgenic maize compared with receptor control at silking stage.There was non-significant difference on the pH, water content, organic matter and available potassium concentration between phyAo transgenic maize and receptor control maize, however, the concentration of available phosphorus and alkali-hydrolyzed nitrogen in rhizosphere soil significantly decreased in phyAo transgenic maize compared with receptor control in jointing stage and maturity growth stage, respectively.The determination of soil enzyme showed there was non-significant difference on activities of invertase and alkaline phosphatase between phyAo transgenic maize and receptor control maize. The activity of urease and acid phosphatase in rhizosphere soil of phyAo transgenic maize significantly decreased in maturity stages. |
