DOI: 10.5061/dryad.b80f6
title: Data from: Spatial soil heterogeneity has a greater effect on symbiotic arbuscular mycorrhizal fungal communities and plant growth than genetic modification with Bacillus thuringiensis toxin genes

description: Maize, genetically modified with the insect toxin genes of Bacillus
 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 Bt maize and their corresponding non-Bt 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 28S rRNA 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 Bt and non-Bt 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 Bt toxin genes.
description: Table S1 Soil
 dataPercent organic matter
 (OM), pH, and soil nitrogen (N) and phosphorus (P) data collected from
 field plots (Corvallis, OR, USA). One composite sample was collected per
 plot and air-dried soils were analyzed for nutrients and soil properties
 at Indiana University.Table S2 MaarjAM OTU
 IDsArbuscular mycorrhizal
 fungi (Family, Genus, Species) in roots of Bacillus thuringiensis (Bt) and
 non-Bt maize cultivated in a field experiment (Corvallis, Oregon, USA).
 Closest matching (97% nucleotide sequence identity) accession numbers were
 obtained via BLAST searches in the MaarjAM reference sequence
 database(http://maarjam.botany.ut.ee/). The accession numbers are linked
 to the National Center for Biotechnology Information
 (NCBI).Table S3 Growth AMF
 data_all plotsData file of growth
 response and percent root colonization by arbuscular mycorrhizal fungi
 (AMF) for Bacillus thuringiensis (Bt) maize plants and their non-Bt
 parental isolines harvested from a field experiment 60 days after sowing
 (Corvallis, OR, USA). Data were collected from a total of 360 plants in 20
 replicate field plots. The Legend, which provides information pertaining
 to each column heading, is located on the second sheet of the Excel
 file.Table S4 Growth AMF and
 OTU data_molecular plotsData file of growth
 responses, percent root colonization by arbuscular mycorrhizal fungi
 (AMF), and operational taxonomic units (OTU) obtained by 454
 pyrosequencing for Bacillus thuringiensis (Bt) maize and non-Bt parental
 isolines harvested from a subset of five plots in a field experiment 60
 days after sowing (Corvallis, OR, USA). The X,Y coordinates (cm) for each
 plant were used in the analysis of spatial variability of AMF communities
 (Mantel Correlogram; Fig. 4). The Legend, which provides information
 pertaining to each column heading, is located on the second sheet of the
 Excel file.Figure S1 Plot
 LayoutPlot layout of a field
 experiment conducted from June through August 2011 (Corvallis, OR, USA) to
 test the effects of Bacillus thuringiensis (Bt) and non-Bt maize on the
 colonization ability and community diversity of arbuscular mycorrhizal
 fungi (AMF) in roots. Each plot measured 1 m by 1.2 m in size and there
 was a 1 m unplanted border around all plots. Each plot contained 20 plants
 (14 different cultivars B1-B9 and P1-P5) and each Bt cultivar was sown
 next to its non-Bt parental (P) isoline. Corresponding Bt/P pairs are
 indicated in the plot map as follows: B1/P1 = pink; B2/P2 = yellow; B3/P3
 = purple; B4/P4 = gray; B5/P3 = brown; B6/P2 = green; B7/P5 = red; B8/P5 =
 blue; and B9/P5 = orange. Plant IDs followed by a "T" (in white)
 were used to trap spores for later experiments and are thus not included
 in the present study. Plant growth responses and percent AMF colonization
 in roots were recorded for all plants in the experiment (360 plants). Root
 samples collected from a subset of plots (2, 8, 10, 14, and 16; outlined
 in black) were used for molecular analysis of AMF communities using 454
 pyrosequencing (90 plants).Figure S2 Alpha
 Rarefaction PlotsRarefaction analysis of
 AMF communities in Bacillus thuringiensis (Bt) and non-Bt maize roots from
 a field experiment (Corvallis, OR, USA). Plots were generated by Qiime and
 use the Chao1 metric to measure alpha diversity in each sample at multiple
 levels of rarefaction.Alpha Rarefaction
 Plots.zipOTU Consensus
 SequencesFASTA file containing
 the consensus DNA sequences for the 143 operational taxonomic units (OTU)
 generated by AbundantOTU with a 97% sequence identity cutoff. Taxonomic
 information for each sequence is available in Table S2 and the read count
 for each OTU per sample is available in Table S4.