自2014年起建立了转cry1Ab基因水稻（GM）及其对照非转基因水稻（M）的田间试验。分别利用16S rRNA基因的Illumina MiSeq 高通量测序及amoA, nirS和 nirK基因的实时定量PCR，分析了田间试验第五年稻田土壤细菌群落和驱动氮素转化的功能基因丰度的变化。结果显示：转基因水稻GM的土壤细菌群落的a多样性指数，包括物种丰富度指数Chao1、香农多样性指数Shannon和辛普森多样性指数Simpson，在水稻各个生育期内均与非转基因水稻M间没有差异。但是基于unweighted UniFrac距离的主坐标分析(Principal coordinates analysis，PCoA)和非度量多维尺度分析(Nonmetric Multidimensional scaling，NMDS)显示，转基因水稻GM的细菌群落与非转基因水稻M在水稻各个生育期内均存在分布差异。且基于unweighted UniFrac距离的ADONIS和ANOSIM分析结果表明上述GM与M的细菌群落分布差异都达到显著性水平(P<0.05)。GM土壤中酸杆菌门 Acidobacteria和M土壤中拟杆菌门Bacteroidetes相对丰度的增加可导致其细菌群落的差异。同时，高通量测序的基因功能预测结果显示，在水稻成熟期转基因水稻GM土壤中一些功能基因丰度提高，如与淀粉、氨基酸和氮代谢相关的基因。此外，转基因水稻GM土壤中的氨氧化细菌amoA基因、氨氧化古菌amoA基因及反硝化细菌nirK基因的丰度均显著增加(P<0.05 或 0.01)。总之，转cry1Ab基因水稻对土壤细菌群落组成和微生物功能基因丰度均存在影响。

Ammonia oxidation, the first and rate-limiting step of nitrification, is carried out by both ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA). However, the relative importance of AOB and AOA to nitrification in terrestrial ecosystems is not well understood. The aim of this study was to investigate the effect of the nitrogen input amount on abundance and community composition of AOB and AOA in red paddy soil. Soil samples of 10-20 cm (root layer soil) and 0-5 cm (surface soil) depths were taken from a red paddy. Rice in the paddy was fertilized with different rates of N as urea of N1 (75 kg N ha-1 yr-1), N2 (150 kg N ha-1 yr-1), N3 (225 kg N ha-1 yr-1) and CK (without fertilizers) in 2009, 2010 and 2011. Abundance and community composition of ammonia oxidizers was analyzed by real-time PCR and denaturing gradient gel electrophoresis (DGGE) based on amoA (the unit A of ammonia monooxygenase) gene. Archaeal amoA copies in N3 and N2 were significantly (P<0.05) higher than those in CK and N1 in root layer soil or in surface soil under tillering and heading stages of rice, while the enhancement in bacterial amoA gene copies with increasing of N fertilizer rates only took on in root layer soil. N availability and soil NO3 --N content increased but soil NH4 +-N content didn’t change with increasing of N fertilizer rates. Otherwise, the copy numbers of archaeal amoA gene were higher (P<0.05) than those of bacterial amoA gene in root lary soil or in surface soil. Redundancy discriminate analysis based on DGGE bands showed that there were no obvious differs in composition of AOA or AOB communities in the field among different N fertilizer rates. Results of this study suggested that the abundance of ammonia-oxidizers had active response to N fertilizer rates and the response of AOA was more obvious than that of AOB. Similarity in the community composition of AOA or AOB among different N fertilizer rates indicate that the community composition of ammonia-oxidizers was relatively stable in the paddy soil at least in short term for three years.