Microbial Cross-Talk: Dissecting the Core Microbiota Associated With Flue-Cured Tobacco (Nicotiana tabacum) Plants Under Healthy and Diseased State

Waqar Ahmed; Zhenlin Dai; Qi Liu; Shahzad Munir; Jun Yang; Samantha C Karunarathna; Shichen Li; Jinhao Zhang; Guanghai Ji; Zhengxiong Zhao

doi:10.3389/fmicb.2022.845310

Microbial Cross-Talk: Dissecting the Core Microbiota Associated With Flue-Cured Tobacco (Nicotiana tabacum) Plants Under Healthy and Diseased State

Front Microbiol. 2022 Apr 14:13:845310. doi: 10.3389/fmicb.2022.845310. eCollection 2022.

Authors

Waqar Ahmed^{1

2

3}, Zhenlin Dai^{2

3}, Qi Liu^{2

3}, Shahzad Munir², Jun Yang^{2

3

4}, Samantha C Karunarathna⁵, Shichen Li⁶, Jinhao Zhang^{2

3}, Guanghai Ji^{2

3}, Zhengxiong Zhao¹

Affiliations

¹ College of Resources and Environment, Yunnan Agricultural University, Kunming, China.
² State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Agricultural University, Kunming, China.
³ Key Laboratory of Agro-Biodiversity and Pest Management of Ministry of Education, Yunnan Agricultural University, Kunming, China.
⁴ College of Resources, Environment, and Chemistry, Chuxiong Normal University, Chuxiong, China.
⁵ Biological Resources Protection and Utilization, College of Biological Resources and Food Engineering, Qujing Normal University, Qujing, China.
⁶ College of Agronomy and Biotechnology, Yunnan Agricultural University, Kunming, China.

Abstract

Bacterial wilt caused by Ralstonia solanacearum is a devastating disease of flue-cured tobacco production which poses significant yield losses all around the world. In this study, we evaluated the rhizosphere microbiome of healthy and bacterial wilt-infected (diseased) flue-cured tobacco plants through amplification of V3-V4 and ITS1-5f variable regions of 16S and internal transcribed spacer (ITS) rRNA. The study was based on the location (Qujing, Shilin, and Wenshan), plant components (rhizosphere soil and roots), and sample types (healthy and diseased) to assess the diversity of bacterial and fungal communities. Bacterial and fungal communities present in roots primarily emanated from rhizosphere soil. Healthy flue-cured tobacco plants exhibit high microbial diversity compared to diseased plants. Among three variables, plant components significantly influence the diversity of microbial communities, whereas rhizosphere soil harbors higher microbial diversity than roots. Bacterial phyla Cyanobacteria and Proteobacteria were found in high relative abundance in roots and rhizosphere soil samples, respectively. As far as fungi is concerned, a high relative abundance of Ascomycota and Basidiomycota was found in both rhizosphere soil and root. Bacterial genera such as Bacillus, Bradyrhizobium, Ensifer, Neorhizobium, and Lysobacter related to plant growth promotion and disease suppressing abilities were dominant than fungal genera. Analysis of relative abundance at specie-level revealed that most fungal species are pathogenic to flue-cured tobacco and could provide a conducive environment for wilt infection. In conclusion, R. solanacearum significantly influences the microbial diversity of flue-cured tobacco plants and negatively affects the bacterial community composition. Altogether, our study demonstrates the complexity of bacterial and fungal communities that possibly interact with each other (microbe-microbe) and host (host-microbe). This cross-talk could be helpful for healthy flue-cured tobacco plant growth and to induce resistance against bacterial wilt disease.

Keywords: Ralstonia solanacearum; disease resistance; flue-cured tobacco; locations; microbial diversity; plant components.