Generalist herbivorous insect modulates similar rhizosphere bacterial communities across different plant species

Abstract

Plants and insects have developed an evolutionary relationship over time. It is known that aboveground insect damage influences molecular modifications in plant defense systems, leading to changes in root exudation patterns and carbon allocation. Mounting evidence demonstrated in specific crops shows that plants modulate their rhizosphere microbes in response to leaf-herbivory attack. However, the influence of a specific herbivore on rhizosphere microbiomes across different crop species and its communalities remains unknown. Here, we studied the relationships between aboveground insect herbivory (Trichoplusia ni) damage and rhizosphere microbiome effects across five plant species (Zea mays ‘sh2,’ Phaseolus vulgaris L. ‘Seychelles,’ Solanum lycopersicum ‘Rutgers,’ Beta vulgaris L. ‘Burpee Bred,’ and Arabidopsis thaliana Ecotype Col-0). We investigated whether insect damage may influence the recruitment of beneficial microbes across plant species to minimize the burden associated with the attack. Our results show a significant increase in the rhizosphere abundance of certain beneficial microbial taxa including Azospirillum, Burkholderia, and Arthrobacter, consistently across all plant species tested. Furthermore, a significant reduction in the biomass was observed among the second generation of plants grown under the conditioned soil without insect damage.