Wild wisdom meets cultivation: comparative rhizomicrobiome analysis unveils the key role of Paraburkholderia in growth promotion and disease suppression in Coptis chinensis.

Background: The sustained monoculture and irregular planting practices rendered the cultivated Coptis chinensis more prone to various diseases compared to its wild counterparts. Rewilding the rhizomicrobiome of cultivated plants has emerged as a promising strategy to promote plant growth, but ancestral microbiota suitable for C. chinensis remain largely uncharted.

Results: The amplicon data analyses revealed that habitat transition strongly influenced the rhizosphere microbial communities. The rhizomicrobiomes of wild C. chinensis encompassed a more diverse array of ecological groups and exhibited a greater functional diversity compared to their cultivated counterparts. A higher proportion of beneficial fungi was observed in the rhizosphere of wild C. chinensis, while the cultivated plants had a higher population of pathogenic fungi. Furthermore, a well-documented plant-growth-promoting rhizobacterium genus, Paraburkholderia, was found to play an essential role in the resistance of the wild C. chinensis to potential disease caused by Ilyonectria. Two strains of Paraburkholderia (Paraburkholderia nemoris and Paraburkholderia phytofirmans) were isolated, and in vitro experiments confirmed that these isolates possess various growth-promoting properties and antagonistic activities against known pathogens for C. chinensis root rot. Both of the Paraburkholderia isolates could markedly promote the plant immune response and enhance the overall health of the cultivated C. chinensis.

Conclusions: By a comprehensive comparison of the rhizosphere microbiome between wild and cultivated C. chinensis, the promising bacterial genus Paraburkholderia was identified as a beneficial microbe significantly promoting the growth of C. chinensis, providing pivotal insights for future endeavors aimed at engineering the rhizosphere microbiome of C. chinensis, as well as other medicinal herbs. Video Abstract.