Resistomes are ubiquitous in natural environments. Previous
studies
have shown that both the plant phyllosphere and soil-borne nematodes
were reservoirs of above- and below-ground resistomes, respectively.
However, the influence of plant identity on soil, nematode, and phyllosphere
resistomes remains unclear. Here, a microcosm experiment was used
to explore the characteristics of bacterial communities and resistomes
in soil, nematode, and phyllosphere associated with six different
plant identities (Lactuca sativa, Cichorium
endivia, Allium fistulosum, Coriandrum
sativum, Raphanus sativus, and Mesembryanthemum
crystallinum). A total of 222 antibiotic resistance genes
(ARGs) and 7 mobile genetic elements (MGEs) were detected by high-throughput
quantitative PCR from all samples. Plant identity not only significantly
affected the diversity of resistomes in soil, nematode, and phyllosphere
but also influenced the abundance of resistomes in nematodes. Shared
bacteria and resistomes indicated a possible pathway of resistomes
transfer through the soil–nematode–phyllosphere system.
Structural equation models revealed that plant identity had no direct
effect on phyllosphere ARGs, but altered indirectly through complex
above- and below-ground interactions (soil-plant-nematode trophic
transfer). Results also showed that bacteria and MGEs were key factors
driving the above- and below-ground flow of resistomes. The study
extends our knowledge about the top-down and bottom-up dispersal patterns
of resistomes.