The structure and assembly of rhizobacterial communities are influenced by poplar genotype

Qi Liang Zhu; Kun Yan; Nian Zhao Wang; Shu Qi Ma; De Shan Lu; Xiao Hua Su; Zheng Sai Yuan; Yu Feng Dong; Yan Ping Wang; Chang Jun Ding

doi:10.3389/fmicb.2022.1052567

The structure and assembly of rhizobacterial communities are influenced by poplar genotype

Front Microbiol. 2022 Nov 29:13:1052567. doi: 10.3389/fmicb.2022.1052567. eCollection 2022.

Authors

Qi Liang Zhu^{1

2}, Kun Yan¹, Nian Zhao Wang¹, Shu Qi Ma¹, De Shan Lu¹, Xiao Hua Su^{2

3}, Zheng Sai Yuan^{2

3}, Yu Feng Dong⁴, Yan Ping Wang¹, Chang Jun Ding^{2

3}

Affiliations

¹ Taishan Forest Ecosystem Research Station of State Forestry Administration, College of Forestry, Shandong Agricultural University, Tai'an, China.
² State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China.
³ Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China.
⁴ Shandong Academy of Forest, Jinan, China.

Abstract

The interaction between plants and microbes dominates plant growth and fitness in specific environments. The study of the relationship between plant genotypes and rhizobacterial community structure would provide a deep insight into the recruitment strategies of plants toward soil bacteria. In this study, three genotypes of 18-year-old mature poplar (H1, H2, and H3) derived from four different parents were selected from a germplasm nursery of Populus deltoides. Rhizosphere soil carbon, nitrogen, and phosphorus properties as well as the 16S rDNA sequences of rhizobacterial communities were analyzed to determine the relationship between poplar genotypes and rhizobacterial communities assembly. The results showed there were significant differences in the diversity (Chao1, ACE index, and Shannon index) of rhizobacterial communities between H1 and H2, as well as between H2 and H3, but no difference between H1 and H3. Principal component analysis also revealed a similar structure of rhizobacterial communities between H1 and H3, whereas the rhizobacterial communities of H2 demonstrated significant differences from H1 and H3. Linear discriminant effect size analysis indicated that there were 11 and 14 different biomarkers in the H1 and H3 genotype, respectively, but 42 in the H2 genotype. Co-occurrence network analysis indicated that the rhizobacterial communities of H2 had a distinct network structure compared to those of the other two genotypes, whereas H1 and H3 had a similar pattern of co-occurrence network. Threshold indicator taxa analysis revealed that 63 genera responded significantly to NO₃ ^--N content and 58 genera to NH₄ ⁺-N/NO₃ ^--N ratio. Moreover, the stochastic assembly process was found to be decreased with increasing NO₃ ^--N content and fluctuated with increasing NH₄ ⁺-N/NO₃ ^--N ratio. All results indicated that the structure of poplar rhizobacterial communities were influenced by host genotypes, and available nitrogen might play a dominant role in the assembly of rhizobacterial communities. This study would promote the future selection and utilization of rhizobacteria in poplar breeding.

Keywords: co-occurrence network; community assembly; plant-microbe relationship; poplar genotype; rhizobacterial community.

Grants and funding

This work was funded by the National Key Research and Development Program of China (2021YFD2201205), the National Natural Science Foundation of China (32071751 and 31870662), and the Key Research and Development Program of Shandong Province (2021SFGC020503).