3Center for Rhizosphere Biology, Department of Horticulture and Landscape Architecture, Colorado State University, Fort Collins, CO, 80523, USA.
* Corresponding author:j.vivanco@colostate.edu, (970) 443-6096
This work was supported by Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) grant 2014/50275-9, Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) grant 482737/2012-3 to MCSF, Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) – Finance Code 001, a USDA-Cooperative Agreement, and the Colorado State University Agricultural Experiment Station. MLM was the recipient of the FAPESP/DR fellowship 2016/18001-1 and FAPESP/BEPE fellowship 2017/05465-2. MCSF is also a research fellow of CNPq.
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 includingAzospirillum , Burkholderia , and Arthrobacte r, 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.
Keywords: 16S rRNA, herbivory, insects, plants, bacteria, rhizosphere, microbiota.
We thank members of Professor Vivanco’s group for helping us with the discussion and providing valuable comments. We also thank Dr. Alison K. Hamm (USDA- ARS Soil Management and Sugar Beet Research Unit, Fort Collins, CO, USA) for technical assistance.