Effects Of Transgenic Rice Expressing RNA Interference Vectors Of Nematode Genes Mg289 And MgGPP On Soil Microbial Diversity

Meloidogyne graminicola is one of the most important pathogenic nematodes in rice and causes great losses to the rice industry each year.Transgenic rice expressing RNA Interference(RNAi)vectors of M.graminicola genes can effectively resist M.graminicola.With the expansion of the planting area of genetically modified crops,studying effects of transgenic plants on microorganisms in soils is important,which can help evaluate the safety of genetically modified crops.In this study,two in planta RNAi transgenic rice lines,Mg289 RNAi transgenic rice and MgGPP RNAi transgenic rice,were used to verify their resistance to M.graminicola and effects of the two RNAi transgenic rice on diversity of soil microbial and community structure by high-throughput sequencing techniques.The object is to evaluate if these two RNAi transgenic rice lines are safe to environment,providing a theoretical basis for assessing the environmental security of trangenic plants.Main results are as follows:1.Mg289 RNAi transgenic rice and MgGPP RNAi transgenic rice were inoculated used M.graminicola,the results showed that the number of females in the root of Mg289 in planta RNAi transgenic rice was reduced by 50-59% compared to the non-transgenic rice;the number of females in the roots of MgGPP RNAi transgenic rice was reduced by 20-42% compared to non-transgenic rice,demonstrating the two RNAi transgenic rice were able to effectively resist the invasion of the nematode.2.The 16 S V4 region and ITS1 region amplicon sequencing technology were used to study the diversity of soil bacteria and fungus communities of the two transgenic rice plants.Compared with non-transgenic rice,it was found that the variation trend of the bacteria OTU number in the three rice soils was similar.The OTU increased with the growth and development of rice.Of these,Proteobacteria and Proteobacteria are the prominent bacteria in three types of rice soil.Additionally,the variation trend of fungi OTU number in three soils of rice was also consistent,that is,the number of OTU increased first and then decreased.In rice heading stage,the number of soil fungi was the largest,and Ascomycota and Basidiomycotina were the prominent fungus.3.In the study of the effects of two transgenic rice varieties on soil bacterial community diversity,it was found that in the rice heading and harvesting stages,the diversity index of Mg289 RNAi transgenic rice was not significantly different from non-transgenic rice,but in the rice tillering stage,there was significant difference in the Chao1 index between non-transgenic rice and Mg289 RNAi transgenic rice.By the PCA analysis and Anosim analysis,there was no significant difference in the bacterial community structure of transgenic rice plants with Mg289 RNAi at the tillering stage and heading stage compared with non-transgenic rice.However,in the rice harvesting stage,the bacterial community structure between non-transgenic plants and Mg289 RNAi transgenic rice were significantly different,suggesting that the Mg289 RNAi transgenic rice impacted the bacterial community structure during the harvest period.However,there was no significant difference in the bacterial diversity and the community between MgGPP RNAi transgenic rice and non-transgenic rice in the three periods of rice growth,suggesting that MgGPP RNAi transgenic rice had no significant effect on the soil bacterial community.4.There was no significant difference on soil fungal community diversity among Mg289 RNAi transgenic rice,MgGPP RNAi transgenic rice and non-transgenic rice at the three time of tillering,heading and harvesting stages of rice growth.It was therefore suggested that the two transgenic rice had no significant effect on the soil fungal community.In this study,effects of the two RNAi transgenic rice lines on soil microbes during the tillering,heading and harvesting stages of rice were evaluated,because different kinds of RNAi transgenic rice have different effects on soil microbes,we think whether RNAi transgenic plants will affect soil microbes and the selected genes.Transferring different genes will lead to different results.