Premium
Spatial soil heterogeneity has a greater effect on symbiotic arbuscular mycorrhizal fungal communities and plant growth than genetic modification with B acillus thuringiensis toxin genes
Author(s) -
Cheeke Tanya E.,
Schütte Ursel M.,
Hemmerich Chris M.,
Cruzan Mitchell B.,
Rosenstiel Todd N.,
Bever James D.
Publication year - 2015
Publication title -
molecular ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.619
H-Index - 225
eISSN - 1365-294X
pISSN - 0962-1083
DOI - 10.1111/mec.13178
Subject(s) - biology , colonization , glomeromycota , host (biology) , biomass (ecology) , botany , shoot , colonisation , bacillus thuringiensis , endophyte , agronomy , symbiosis , mycorrhiza , ecology , bacteria , genetics
Maize, genetically modified with the insect toxin genes of B acillus thuringiensis ( Bt ) , is widely cultivated, yet its impacts on soil organisms are poorly understood. Arbuscular mycorrhizal fungi ( AMF ) form symbiotic associations with plant roots and may be uniquely sensitive to genetic changes within a plant host. In this field study, the effects of nine different lines of B t maize and their corresponding non‐ B t parental isolines were evaluated on AMF colonization and community diversity in plant roots. Plants were harvested 60 days after sowing, and data were collected on plant growth and per cent AMF colonization of roots. AMF community composition in roots was assessed using 454 pyrosequencing of the 28 S r RNA genes, and spatial variation in mycorrhizal communities within replicated experimental field plots was examined. Growth responses, per cent AMF colonization of roots and AMF community diversity in roots did not differ between B t and non‐ B t maize, but root and shoot biomass and per cent colonization by arbuscules varied by maize cultivar. Plot identity had the most significant effect on plant growth, AMF colonization and AMF community composition in roots, indicating spatial heterogeneity in the field. Mycorrhizal fungal communities in maize roots were autocorrelated within approximately 1 m, but at greater distances, AMF community composition of roots differed between plants. Our findings indicate that spatial variation and heterogeneity in the field has a greater effect on the structure of AMF communities than host plant cultivar or modification by B t toxin genes.