Changes Of Root Microbes In Rice During The Whole Growth Period Under Different Nitrogen Levels

The root system of terrestrial plants is enriched with a large number and a wide variety of microorganisms,collectively called the root microbiome.These microorganisms participate in important physiological processes such as plant growth and development,nutrient absorption and disease resistance.Rice is one of the most important food crops and plays an irreplaceable role in developing agriculture and ensuring human food security.In order to increase rice yield,the application of a large amount of nitrogen fertilizer not only wastes a lot of resources,but also causes serious pollution to the environment.The rise of root microbiome research has provided new technologies and ideas for solving the above problems.Previous studies have shown that the microbiome of rice roots gradually changes with the growth and development time under field conditions,but little is known about the changes of the root microbiome during the whole life cycle of rice under different nitrogen levels in the field.In this project,two representative rice cultivars were planted in two experimental fields with different nitrogen levels: Nipponbare(japonica)and IR24(indica rice).The root microbiome of the whole growing period of rice was continuously sampled and set up at another site.Repeated experiments were performed to track the change of rice root microbiome with growth and development time under different nitrogen conditions.The experimental results show: 1.Rice growth and development changes: Through the detection of root microorganisms,it was found that under both nitrogen levels,the root microbiome gradually changed with the growth and development time of the rice.The PCOA chart shows that the soil microbiome changes basically with the rice planting time series are not big,but the rice root microbiome is constantly changing.2.PCOA and two-point analysis dot plots showed that the root microbiome tended to be stable at 8-10 weeks,and we found that the time for the rice root microbiome to reach a stable phase under different nitrogen conditions was different.Rice root microbiome under high nitrogen conditions reached stability at week 10,and rice root microbiome under low nitrogen conditions reached stability at week 9,indicating that rice under low nitrogen conditions entered the reproductive stage than those under high nitrogen conditions is one week earlier,which is in line with related studies on plants entering the reproductive period under nutritional stress.3.Establish models through machine learning to find specific bacterial biomarkers of rice root system during the whole growth period under different nitrogen levels.4.Rice root microbiome at different nitrogen levels differs at different classification levels,laying the foundation for the subsequent discovery of nitrogen-related functional bacteria.This study initially revealed the changes of rice root microbiome under different nitrogen levels during the rice growth and development period.By comparing the differences in the rice root microbiome under different nitrogen levels,it laid the foundation for the subsequent discovery of related functional experiments such as timedependent correlation bacteria,nitrogen-related functional bacteria and other related functions.In agricultural production,nitrogen-related functional bacteria can be used to improve the conversion efficiency of rice to nitrogen,increase the absorption and utilization efficiency of nitrogen fertilizer,help reduce the use of chemical fertilizers,and achieve sustainable ecological agriculture..