Effect of soil bioremediation on soil microbial community structure aimed at controlling tobacco bacterial wilt.

Rebuilding soil healthy microbiota is very important for preventing bacterial wilt. A 3-year-long field trial was conducted in China as follows: T1 (conventional fertilization), T2 (T1 + liming), T3 (T1 + bioorganic fertilizer), and T4 (T2 + bioorganic fertilizer). Fluorescence quantitative PCR and high-throughput sequencing were employed to study the dynamics of Ralstonia solanacearum population, microbial community, and network organizations between bacteria and quality-related variables. After 3 years of bioremediation, the control efficacy of tobacco bacterial wilt reached 61.30% and the occurrence delayed by approximately 40 days in T4, which had the highest tobacco yield and output value. The pathogen population of T4 remained below 10 copies/g soil during the entire growth period. Role-shifts prevailed among the network members. Microbes were unipathically associated with variables in T1 but multiplex in T4. In conclusion, soil bioremediation rebuilds a healthy soil microbiota and forms a more interactive and relevant micro-system, thus effectively controlling tobacco bacterial wilt. KEY POINTS: • This is the first time to effectively bio-control tobacco bacterial wilt in practical production in China, as well as to high-efficiently use the organic waste, thus promoting the organic cycling of the environment. • Soil bioremediation can effectively control soil-borne disease by rebuilding soil healthy microbiota and reducing abundance of pathogenic bacteria, thereby to prevent the soil borne disease occurrence. • After the soil remediated, microbes associated with soil and tobacco characteristics changed from unipathical to multiplex, and the keystone species play different roles compared with the original soil, thus signifying the complexity of multi-species interactions and achieving a closely relevant micro-system, which was ecologically meaningful to the environment.