Engineering multifunctional rhizosphere probiotics using consortia of Bacillus amyloliquefaciens transposon insertion mutants
- Nanjing Agricultural University, China
- University of Helsinki, Finland
Abstract
While bacterial diversity is beneficial for the functioning of rhizosphere microbiomes, multi-species bioinoculants often fail to promote plant growth. One potential reason for this is that competition between different species of inoculated consortia members creates conflicts for their survival and functioning. To circumvent this, we used transposon insertion mutagenesis to increase the functional diversity within Bacillus amyloliquefaciens bacterial species and tested if we could improve plant growth-promotion by assembling consortia of highly clonal but phenotypically dissimilar mutants. While most insertion mutations were harmful, some significantly improved B. amyloliquefaciens plant growth-promotion traits relative to the wild-type strain. Eight phenotypically distinct mutants were selected to test if their functioning could be improved by applying them as multifunctional consortia. We found that B. amyloliquefaciens consortium richness correlated positively with plant root colonization and protection from Ralstonia solanacearum phytopathogenic bacterium. Crucially, 8-mutant consortium consisting of phenotypically dissimilar mutants performed better than randomly assembled 8-mutant consortia, suggesting that improvements were likely driven by consortia multifunctionality instead of consortia richness. Together, our results suggest that increasing intra-species phenotypic diversity could be an effective way to improve probiotic consortium functioning and plant growth-promotion in agricultural systems.
Data availability
All data generated or analysed during this study are included in the manuscript and supporting file; Source Data files have been provided in Source data 1
Article and author information
Author details
Funding
National Key Research and Development Program of China (2021YFD1900100)
- Zhong Wei
Royal Society Research Grants (CHL\R1\180031)
- Ville-Petri Friman
Strategic Priorities Fund Plant Bacterial Diseases programme (BB/T010606/1)
- Ville-Petri Friman
National Key Research and Development Program of China (2022YFF1001804)
- Xiaofang Wang
National Key Research and Development Program of China (2022YFD1500202)
- Tianjie Yang
National Natural Science Foundation of China (42325704)
- Zhong Wei
National Natural Science Foundation of China (42090064)
- Qirong Shen
National Natural Science Foundation of China (41922053)
- Zhong Wei
National Natural Science Foundation of China (31972504)
- Yangchun Xu
Fundamental Research Funds for the Central Universities (KYT2023001)
- Zhong Wei
Royal Society Research Grants (RSG\R1\180213)
- Ville-Petri Friman
These funders supported study design, data collection and interpretation, and the decision to submit the work for publication.
Copyright
© 2023, Li et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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