转TaDREB4基因抗旱小麦对其根际土壤速效养分、酶活性及微生物群落多样性的影响

Analysis of available nutrient,enzyme activities and microorganism community diversity in rhizospheric soil of TaDREB4 transgenic wheat with drought resistance

通过研究不同生育期转TaDREB4基因抗旱小麦TB4对其根际土壤速效养分、酶活性和微生物群落的影响,为转基因小麦TB4的生物安全性评价提供科学依据。结果显示,在同一生育期,转基因小麦TB4根际土壤速效养分含量与其受体济麦19(JM19)无显著差异。从播种前到成熟期,速效氮和速效磷含量表现为先上升后下降的趋势,在返青期时达到最大值;速效钾含量则表现为先下降后上升的趋势,在返青期达到最小值。不同生育期之间小麦根际土壤酶活性不同,从播种前到成熟期,脲酶、蔗糖酶和脱氢酶活性都表现为先升高后下降的趋势,在返青期时达到最大值,但在同一生育期,转基因小麦TB4与受体JM19的根际土壤脲酶、蔗糖酶和脱氢酶活性相似,无显著差异。通过PCR-DGGE技术对小麦根际土壤微生物群落多样性进行分析,DGGE指纹图谱表明,同一生育期转基因小麦TB4与受体JM19之间的差异性条带较少,细菌的条带数多于真菌。TB4与JM19在同一生育期的多样性指数(H')、均匀度指数(E)差异不显著,Simpson指数(D)在极少数时期有显著差异。主成分分析(PCA)结果显示,同一生育期转基因与非转基因亲本的样方聚在一起,同一品种不同时期之间的样方距离较远。综上所述,转基因小麦TB4对其根际土壤速效养分含量、酶活性和微生物群落多样性的影响不显著。

The objective of this study was to ana- lyze the effects on the available nutrient, enzyme activities and microorganism （ bacteria and fungi） community in rhi- zospheric soil of TaDREB4 transgenic wheat TB4 with drought resistance. The result shows that the content of a-vailable nutrient in the rhizospheric soil had no significant difference between transgenic wheat TIM and its receptor Jimai 19 （JM19） at the same developmental stage. The content of available nitrogen and phosphorus showed an increased and then decreased trend from pre-seeding to maturity, and reached its maximum at reviving stage. The content of available po- tassium reduced first and then increased and reached its minimum at reviving stage. The transgenic wheat TIM had an simi- lar activities of urease, saccharase and dehydrogenase in rhizospheric soil to Jimai 19 at the same stage, but differed from Jimai 19 in the activities of the three enzymes, which appeared to be rising first then declining and reached its maximum at reviving stage. The polymerase chain reaction-denaturing gradient gel electrophoresis （PCR-DGGE） analysis showed that there had minor distinct band between the transgenic wheat TIM and non-transgenic wheat, and the diversity of bacteria was more abundant than fungi. The diversity index （H＇）, Simpson index （D） and evenness index （E） barely differed between two wheat materials. There was a distinct separation along the principal component axes between TB4 and JM19 at different growth stages. In sum, the content of available nutrients, enzyme activities and microbial community in rhizospheric soil show no significant difference between transgenic wheat TIM and its receptor at the same growth stage, but there are certain differences at different stages.