Characteristics of rhizosphere and endogenous bacterial community of Ulleung-sanmaneul, an endemic plant in Korea: application for alleviating salt stress

Microbes influence plant growth and fitness. However, the structure and function of microbiomes associated with rare and endemic plants remain underexplored. To investigate the bacterial community structure of Ulleung-sanmaneul (U-SMN), an endemic plant in Korea, samples were collected from natural and cultivated habitats, and their 16S rDNA was sequenced. The root bacterial community structure differed from those of bulk soil and rhizosphere in both habitats. Endogenous bacteria in cultivated plants were less diverse than wild plants, but Luteibacter rhizovicinus, Pseudomonas fulva, and Sphingomonas pruni were shared. Co-inoculation of Pseudoxanthomonas sp. JBCE485 and Variovorax paradoxus JBCE486 promoted growth and induced salt stress resistance in Arabidopsis and chive. Changes in growth promotion and phenotypes of plants by co-inoculation were mediated by increased auxin production. Each strain colonized the roots without niche competition. The results indicated that host selectivity was influential than environmental factors in formulating endophytic bacterial composition, and domestication simplified the bacterial community diversity. Our results will contribute to the growth and maintenance of endemic U-SMN plants.

Automated summary

Microbes have an influence on the growth and adaptability of plants, but the microbiomes associated with rare and endemic plants have not been fully explored. This study investigated the bacterial community structure of an endemic plant in Korea and found that the root bacterial community structure differed from that of the soil and rhizosphere. The diversity of endogenous bacteria in cultivated plants was lower than in wild plants, but certain bacterial species were shared. The study also identified certain microbial strains that promoted growth and salt stress resistance in Arabidopsis and chive.