Effect Of Transgenic High Lysine Sorghum On Microbial Diversity Of Rhizosphere Soil

Sorghum is an important food and economic crop,but the lysine content of its grains is low and cannot meet people’s nutritional needs.Therefore,increasing the lysine content is of great significance for the promotion and application of sorghum.However,whether the introduced foreign genes in genetically modified sorghum had an impact on soil ecology is not clear.The evaluation of soil ecological safety of genetically modified crops is an indispensable key step in the research of genetically modified crops.In this study,transgenic sorghum and non-transgenic sorghum were used as materials.The rhizosphere soil microbial structure and functional diversity,soil physical and chemical properties and soil enzyme activity at different development stages were detected by high-throughput sequencing.Traditional physical and chemical properties and soil enzyme activity analysis method and Biolog-ECO plate cuture in order to provide ecological safety evaluation and basis for the commercial application of transgenic sorghum.The results we found were showed as following:1.High-throughput sequencing analysis of rhizosphere soil microbes at different growth stages showed that: The abundance of Rozellomycota in the non-transgenic group at the seedling stage was dramatically higher than that in the transgenic group.Similarly,the abundance of Chloroflexi and Chytridiomycota in the non-transgenic group at the growth stage was significantly higher than that of the transgenic group.The abundance of Actinobacteria was obviously lower than that of the transgenic group,and the abundance of Proteobacteria and Actinobacteria of the non-transgenic group was lower than that of the transgenic group at the mature stage.Then,the abundance of Cyanobacteria was higher than that of the transgenic group,but the other dominant microorganisms had no significant difference.Besides,cluster analysis and alpha diversity index showed that the population structure of transgenic and non-transgenic microbes was similar.The genetically modified high-lysine sorghum had no significant effect on soil microbial diversity.2.The detection of physicochemical properties of rhizosphere soil of sorghum suggested that there was no remarkable difference in p H value,available phosphorus content,available potassium content,organic matter content,and alkali-hydrolyzable nitrogen content between transgenic and nontransgenic genomes in the whole development stage of sorghum,which indicates that transgenic sorghum was not effective on physicochemical properties of rhizosphere soil.3.The determination results of rhizosphere soil enzyme activity of sorghum implied that there was no difference in urease activity,sucrase activity,alkaline phosphatase activity and catalase activity between transgenic and nontransgenic genomes at each developmental stage of sorghum.That is to say,transgenic sorghum had little effect on rhizosphere soil enzyme activity.4.The difference in the overall metabolic activity and carbon source utilization between transgenic sorghum and non-transgenic sorghum was hardly seen in Biolog-ECO plate experiment,which suggested that transgenic sorghum had no significant effect on the functional diversity of rhizosphere soil microorganisms.