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www.sciencemag.org/cgi/content/full/science.1203980/DC1
Supporting Online Material for
Deciphering the Rhizosphere Microbiome for Disease-Suppressive Bacteria
Rodrigo Mendes, Marco Kruijt, Irene de Bruijn, Ester Dekkers, Menno van der Voort,
Johannes H. M. Schneider, Yvette M. Piceno, Todd Z. DeSantis, Gary L. Andersen, Peter A. H. M. Bakker, Jos M. Raaijmakers*
*To whom correspondence should be addressed. E-mail: jos.raaijmakers@wur.nl
Published 5 May 2011 on Science Express
DOI: 10.1126/science.1203980
This PDF file includes:
Materials and Methods Figs. S1 to S8 Tables S1 to S5
References and Notes
2
Materials and Methods
Soil sample collection and storage
The suppressive soil was collected at the end of the 2004 sugar beet growing season
from an agricultural field close to the town of Hoeven, the Netherlands (51º35’10”N
4º34”44’E). Soil was collected at a depth of 0-30 cm from 25 random sites across the
field. The conducive soil was harvested from the margin of the sugar beet field; this
margin was not cultivated to sugar beet and was covered with grasses and weeds, which
were removed prior to soil sampling. Both soils were air dried, sieved (0.5-cm-mesh) to
remove plant debris, and stored in buckets at ambient temperatures. Physical-chemical
analyses on each soil were performed by BLGG-AgroXpertus (Oosterbeek, The
Netherlands).
Bioassay to assess disease suppressiveness of soils
Sugar beet seeds (cv. Alligator) were sown in square PVC pots (width 6 cm; height
8 cm) containing 250 g of soil with an initial moisture content of 10% (v/w). Plants were
grown in a growth chamber at 24°C, 70% relative humidity and 16 hour light, and
watered weekly with standard Hoagland solution (macronutrients only). Disease
suppressiveness was determined for various treatments: i) suppressive soil (S), ii)
conducive soil (C), conducive soil amended with 10% (w/w) of suppressive soil (CS),
suppressive soil heat-treated at 50°C (S50) or 80°C (S80) for 1 hour, or gamma-irradiated
(60 kGray, Isotron, The Netherlands). For heat treatment, the suppressive soil (moisture
content set at 10% v/w) was transferred to a plastic bag and placed in a water bath at
50ºC or 80ºC for 1 hour. The bags with soil were made flat (~ up to 4 cm height) to
increase the contact area with the surrounding water. For each soil treatment, four
replicates were used in a complete randomized experimental design. Four days after seed
germination, the number of seedlings was reduced to eight per pot. The fungal pathogen
Rhizoctonia solani (anastomosis group AG2-2IIIB) was introduced into the soil by
transferring two mycelial agar plugs (5-mm-diameter) of a 1 week-old potato dextrose
agar (PDA) culture to two opposite corners of the pots at 1-cm underneath the soil
surface. The number of infected sugar beet seedlings was scored every two-three days for
a period up to 20 days after pathogen inoculation. The area under the disease progress
curve (AUDPC) was determined according to the statistical methods described by Shaner
& Finney (15).
Rhizosphere DNA isolation and PhyloChip analysis
The rhizosphere microbiomes of sugar beet seedlings grown in soils with different
levels of disease suppression were subjected to metagenomic-based community analysis.
For each of the six soil treatments (identified in Fig. S3), four replicates were used.
Metagenomic DNA was isolated in triplicate from each replicate by using the PowerSoil®
DNA isolation kit (MO BIO Laboratories, Inc.) according to the manufacturer’s
instructions. Microbial profiles for each sample were generated with the PhyloChip assay
(Second Genome, CA, USA). All PCR conditions and universal primers used for
amplification of 16S rDNA genes from bacteria and archaea were as previously described
(7). Fragmentation of the 16S rDNA amplicons, labelling, hybridizations, staining, and
scanning of the PhyloChip were performed according to methods described by Hazen et
3
al. (6). OTU selection for data analysis differed slightly from Hazen et al. (6) as follows.
All OTUs passing PhyCA analysis Stage 1 criteria in this data set were considered for
further analyses, allowing the inclusion of Unclassified OTU, which would be excluded
by Stage 2 analysis. Additionally, the cut-off values for an OTU to pass Stage 1 were rQ1
≥ 0.646, rQ2 ≥ 0.884, and rQ3 ≥ 0.945. Data analyses were performed with Primer-E
software (version 6.1.13, Plymouth Marine Laboratory).
Bacterial isolation from suppressive soil
For the functional analyses, the γ-Proteobacteria were isolated from sugar beet
rhizosphere on semi-selective media. Sixteen sugar beet seeds were sown in pots filled
with 250 g of suppressive or conducive soils and grown for 20 days (N=3). Rhizosphere
(roots with tightly adhering soil) suspensions were prepared, serially diluted and plated
onto i) 1/10th
strength Tryptic Soy Agar (TSA) supplemented with 100 µg ml-1
Delvocid
to prevent fungal growth, and ii) Pseudomonas Agar (PSA) supplemented with 40 µg ml-1
ampicillin, 12.5 µg ml-1
chloramphenicol (16), and 100 µg ml-1
Delvocid. TSA plates
were incubated at 25°C for 5 days and PSA plates for 3 days. From each of the replicate
samples and growth media (TSA and PSA), 96 randomly selected bacterial colonies were
purified and screened for in vitro antagonism towards R. solani. In these in vitro
inhibition assays, the bacterial isolates were point-inoculated at the periphery of 1/5th
strength PDA (pH 7.0) plates and incubated for two days at 25ºC, after which a fresh
mycelial PDA agar plug of R. solani was transferred to the centre of the plate. After an
additional three days of incubation at 25ºC, inhibition of hyphal growth of R. solani was
scored. Out of 576 bacterial isolates randomly collected from the suppressive soil, 19.3%
showed antifungal activity, whereas only 3.3% of 421 isolates randomly collected from
the conducive soil inhibited growth of R. solani.
16S rDNA sequencing and phylogeny
16S rDNA was sequenced by Macrogen Inc. (Seoul, South Korea). Sequences were
trimmed and submitted to the Ribosomal Database Project for species identification (17).
MEGA 3.1 (18) was used to align 16S rDNA sequences and to construct a phylogenetic
tree (UPGMA with 10,000 bootstraps).
Coupling PhyloChip-based metagenomics with culture-based analysis
Two strategies were used to couple the metagenomics-based PhyloChip data with
the results of the culture-based analysis. For the first strategy, using Basic Local
Alignment Search Tool (http://blast.ncbi.nlm.nih.gov), we aligned the 16S rDNA
sequences of representative strains of haplotype clusters I-III (Fig. 4A) with the 16S
rDNA sequences of the five Pseudomonadaceae identified by the PhyloChip approach as
the top 10% dynamic taxa associated with disease suppression (see Table S3). For the
second strategy, 16S rDNA sequences from strains representing the three haplotype
clusters (Fig. 4A) were used for BLAST searches in the GreenGenes database
(http://greengenes.lbl.gov) used for the PhyloChip array design. Subsequently, the best
hits were traced back in our experimental data set revealing that these haplotypes were
indeed more abundant in suppressive soils than in conducive soils (Fig. 4B). Their
respective abundances were calculated according to the conditions described above in the
‘Rhizosphere DNA isolation and PhyloChip analysis’ section.
4
Random transposon mutagenesis
Plasposon mutagenesis of Pseudomonas sp. strain SH-C52 was performed using
pTnMod-OTc (19). From an initial screen of approximately 1,500 random mutants, two
mutants of strain SH-C52 were obtained that had lost in vitro activity against R. solani.
Single plasposon insertions were confirmed by Southern blot analysis with a probe
directed against the tetracycline resistance gene on the plasposon. Plasposon rescue using
BamHI or PstI was performed as previously described (19).
Cloning and sequencing of the thaABCD genes
A fosmid library (7 X genome coverage) with 30-40 kb fragments of genomic DNA
of Pseudomonas sp. strain SH-C52 was constructed according to the protocols of the
manufacturer (Fosmid Library Production kit, Epicentre). Library clones were blotted
onto Hybond N+ membranes (Amersham) and hybridized with dig-labeled probes
directed against specific sequences in the thaB gene. Hybridizations were performed
under stringent conditions (65°C with 0.1xSSC (75 mM NaCl, 7.5 mM sodium citrate,
0.1% sodium dodecyl sulfate). Hybridization-positive clones were subjected to restriction
analyses. Contigs were constructed by cluster analysis of these experimental data by the
unweighted-pair group method using average linkages. Clones 5.1 and 10.1 were sent for
shotgun sequencing (Macrogen, Seoul, Korea). Sequence gaps were closed by primer
walking.
Bioinformatic analyses
Operons and genes were predicted by the Softberry FGENESB program (Softberry,
Inc., Mount Kisco, NY), and the identified open reading frames (ORFs) were analyzed
using BlastX in the NCBI database and PseudoDB (http://xbase.bham.ac.uk). Putative
promoter sequences were identified by the Softberry BPROM program, and putative
terminator sequences were identified by the RNA secondary structure prediction program
of Genebee (http://www.genebee.msu.su/). Specific domains in the deduced protein
sequences of the NRPS genes thaA, thaB and thaC1 were analyzed with PFAM
(http://pfam.sanger.ac.uk/search?tabsearchSequenceBlock). Protein sequences of specific
domains were aligned in ClustalX (version 1.81). Trees were inferred by neighbor joining
using 1,000 bootstrap replicates. Identification of the genes flanking the NRPS genes was
performed by BlastX analysis in NCBI, Pseudomonas.com
(http://v2.pseudomonas.com/), or PseudoDB and by comparison with genes in the
biosynthesis cluster for syringomycin. The C1-domain of thaA as well as the TE domain
of the ninth module of thaB (GenBank HQ888764) were used in BlastP comparisons with
whole genome sequences of Pseudomonas species available in the databases
Pseudomonas.com and PseudoDB. Adenylation (A), thiolation (T), condensation (C) and
thioesterase (TE) domains of the NRPS genes were identified by PFAM
(http://www.sanger.ac.uk/Software/Pfam/). For phylogenetic analyses of the different
domains, alignments were made with ClustalX (version 1.81) and software available at
http://www.ebi.ac.uk/clustalw/. Trees were inferred by Neighbor Joining in ClustalX
using 1,000 bootstrap replicates.
5
Fig. S1. Disease suppressiveness of soils and its microbiological nature. (A) Progress of
Rhizoctonia damping-off disease of sugar beet seedlings in disease suppressive soil (S),
conducive soil (C), conducive soil amended with 10% (w/w) of suppressive soil (CS),
suppressive soil heat-treated at 50°C (S50) or 80°C (S80) for 1 hour. Disease incidence
represents the percentage of sugar beet seedlings with damping-off symptoms (mean
values ±SEM, N=4). For each replicate, eight sugar beet seedlings were used. (B) Area
under disease progress curve (AUDPC) for each of the five different treatments (mean
values ±SEM, N=4). Different letters above the bars indicate statistically significant
differences (P<0.05, Student-Newman-Keuls test).
0
10
20
30
40
50
60
70
80
0 2 4 6 8 10 12 14 16 18 20
Dis
ease
incid
ence (
%)
dpi
S C CS S50 S80
0
10
20
30
40
50
60
S C CS S50 S80
AU
DP
C
A
B
C
A
BC
BC
AB
6
Fig. S2. Effect of γ-irradiation on soil disease suppressiveness. (A) Disease index
ranging from 0 (healthy plant) to 3 (dead plant). (B) Suppressive soil (S) and γ-irradiated
(60 kGray, Isotron, The Netherlands) suppressive soil (SG) were cultivated with sugar
beet. Number of infected plants (mean values ±SEM, N=12) were scored 14 days after
germination. Asterisk indicates a statistically significant difference (P<0.05, Student’s t-
test).
0
0.5
1
1.5
2
2.5
S SG
Dis
ease
Index
*
0 1 2 3
B A
7
I - Experimental design
1 Sugar beet grown in the presence of R. solani
(N=4).
2 Sugar beet grown in the absence of R. solani
(N=4).
* Treatments selected
for PhyloChip analysis.
II - PhyloChip analysis
1 Rhizosphere DNA isolation with PowerSoil
® MO BIO kit.
2 16S rDNA amplification; pool of 8 X PCR (temperature gradient for annealing from 52 to 62°C) for each replicate.
3 Fractionate (50 to 200 bp) and end-label with biotin.
4 Hybridize, stain, wash and scan; total of 24 chips (6 treatments; N=4).
5 Data analyses using software Richness > Evenness > Hierarchical clustering (Bray Curtis Similarity) > Primer-E. > Ordination (MDS) > Microbial Communities Dynamics (SIMPER analysis).
6 Selection of the target groups based on three criteria. i. more abundant in suppressive than in conducive soil (S>C);
Pairwise comparison of top ii. more abundant in the 'transplantation soil' than in conducive soil (CS>C);
10% dynamic taxa. iii. more abundant in the suppressive soil when the pathogen is present (Sr>S).
III – Isolation of specific bacterial taxa targeted by PhyloChip analysis
1 Bacterial isolation from General aerobic growth medium (TSA) and suppressive and conducive Pseudomonadaceae semi-selective medium (PSA).
soils (~1000 random isolates).
2 Genetic and phenotypic Screening for antagonistic traits (in vitro tests, PCR) > BOX-PCR > characterization (107 isolates). > 16S rDNA sequencing > in vivo bioassays.
3Coupling culture-based analysis with PhyloChip analysis.
Alignments and BLAST searches in the GreenGenes database using 16S rDNA
sequences of the functional bacterial groups.
IV - Genes and pathways involved in disease suppression
1 Genetic, bioinformatic, and functional analyses
Mutagenesis > Genome library constructions > Sequencing > Signature-sequence-based predictions > in vivo bioassays.
8
Fig. S3. Overall strategy used to decipher the rhizosphere microbiome of sugar beet seedlings
grown in disease suppressive soil. Soils with different levels of disease suppression are
designated as: suppressive soil (S); conducive soil (C); conducive soil amended with 10%
(w/v) suppressive soil (CS); suppressive soil heat treated at 50°C (S50); suppressive soil heat
treated at 80°C (S80); and suppressive soil inoculated with the fungal pathogen Rhizoctonia
solani (Sr). For each replicate of each treatment (N=4), total DNA was isolated and pooled
from three independent extractions using 250 mg of rhizosphere soil.
9
Fig. S4. Composition of bacterial communities in the rhizosphere microbiome of sugar
beet seedlings grown in soils with different levels of disease suppressiveness. The sum of
the microbial abundance of all six soil treatments (N=4) is shown.
Acidobacteria, 2%
Actinobacteria, 9%
Bacteroidetes, 4%
Chloroflexi, 1%
Cyanobacteria, 1%
Firmicutes, 20% Planctomycetes, 2%
Proteobacteria, 39%
Unclassified, 16%
Verrucomicrobia, 2%
All others, 4%
10
Fig. S5. Non-metric multi-dimensional scaling (MDS) ordination of the rhizosphere
microbiomes of sugar beet seedlings grown in soils with different levels of disease
suppressiveness. Based on the relative abundance of 33,346 taxa identified in the sugar
beet rhizosphere microbiome, a resemblance matrix was generated using Bray Curtis
similarity. MDS analysis was performed with Primer-E (version 6.1.13).
▲ suppressive soil (S); ▼ conducive soil (C); ● conducive soil amended with 10% (w/v)
suppressive soil (CS); suppressive soil heat treated at 50°C (S50); ■ suppressive soil
heat treated at 80°C (S80) for 1 hour; and X suppressive soil inoculated with Rhizoctonia
solani (Sr).
2D Stress: 0.06
11
A Proteobacteria B Firmicutes
C Cyanobacteria
Fig. S6. Clustering analysis of the rhizosphere microbiome for (A) Proteobacteria, (B)
Firmicutes, and (C) Cyanobacteria. When separate clustering analyses were performed
for the Proteobacteria or Firmicutes, each of these groups allowed discrimination between
the six soil treatments as was the case in the overall cluster analysis (see Fig. 2B),
reinforcing their association with disease suppressiveness. In contrast, for other phyla
such as the Cyanobacteria (C) dissimilar patterns were found.
S8
0_
1
S8
0_
4
S8
0_
2
S8
0_
3
C_
1
C_
4
C_
2
C_
3
S_
2
S_
1
S_
3
S_
4
CS
_3
CS
_4
CS
_1
CS
_2
Sr_
1
Sr_
3
Sr_
2
Sr_
4
S5
0_
4
S5
0_
3
S5
0_
1
S5
0_
2
100
90
80
70
60
50B
ray C
urt
is S
imila
rity
C C C C S S S S Sr
Sr
Sr
Sr
S5
0
S5
0
CS
CS
CS
CS
S5
0
S5
0
S8
0
S8
0
S8
0
S8
0
100
90
80
70
60
50
Bra
y C
urt
is S
imila
rity
S5
0
S5
0 Sr
Sr
Sr
Sr
S5
0
S5
0
CS
CS
CS
CS
S8
0
S8
0
S8
0
S8
0 S S C C C C S S
100
90
80
70
60
50
Bra
y C
urt
is S
imila
rity
12
Fig. S7. Suppression of Rhizoctonia damping-off disease by selected strains of the γ-
Proteobacteria. (A) Representation of the in vivo bioassay to determine the ability of
antagonistic bacterial isolates to suppress damping-off disease of sugar beet seedlings
caused by Rhizoctonia solani. A mycelial plug of the fungal pathogen is point-inoculated
at 1-cm underneath the soil surface at the edge of the tray (indicated by an arrow). Within
a time period of 2-3 weeks, R. solani progressively infects sugar beet seedlings
positioned in a 20-cm row with a 1-cm distance between the seedlings. The level of
disease suppression is quantified by measuring the disease spread as indicated by
seedlings with damping-off symptoms. (B) Spread of damping-off disease of sugar beet
seedlings in conducive soil that is untreated (Control), treated with Pseudomonas sp.
strain SH-A1 (haplotype A), strain SH-B3 (haplotype B) and strain SH-C52 (haplotype
C), and the nonribosomal peptide synthetase mutant of strain SH-C52 (O33).
Pseudomonas sp. strains representing haplotypes A, B and C, and mutant O33 were
inoculated in soil (105 cells g
-1 soil) one day prior to pathogen inoculation (mean values
±SEM, N=8). An asterisk indicates a statistically significant difference (P<0.05, Dunnett
test) between the treatment and the untreated conducive soil (Control).
0 5 10 15 20
O33
SH-C52
SH-B3
SH-A1
Control
Spread of R. solani (cm)
0 5 10 15 20 q
Distance (cm)
R. solaniinoculation point
A
B
*
13
Fig. S8. Schematic representation of the biosynthetic gene clusters responsible for the
antifungal activity of Pseudomonas sp. strain SH-C52. (A) Genetic organization of the
thaAB (29.7-kb) and thaC1C2D (4.4-kb) gene clusters identified in Pseudomonas sp.
strain SH-C52. Underneath the nonribosomal peptide synthetase (NRPS) genes thaA,
thaB and thaC1, is the module and domain organization of the encoded proteins. The
domains are labeled by: C, condensation; A, adenylation; T, thiolation and TE,
thioesterification. The first module is predicted to be an initiation module as it harbours a
condensation (C)-domain with structural features that are typical for C-domains involved
in N-acylation of the first amino acid of the molecule. Modules 2 through 9 are predicted
to elongate the peptide chain via incorporation of one amino acid per module. Together
these nine catalytic domains are predicted to generate a peptide which is cleaved at the
end of the assembly line by a thioesterase (TE) domain, resulting in the release of a linear
product or a cyclic peptide via an intramolecular cyclization reaction. Based on the
signature sequences in the adenylation (A)-domains, 6 of the amino acid residues in the
peptide moiety could be predicted but 3 could not. Genes thaC1 and thaC2 share
similarities with syrB1 and syrB2, respectively, the latter being involved in chlorination
of the ninth amino acid residue (Thr) of syringomycin, the lipopeptide antibiotic
produced by P. syringae. ThaD has 73% sequence identity to SyrC, an
aminoacyltransferase that shuttles threonyl and chlorothreonyl residues to the syr-syp
biosynthetic assembly line in P. syringae. Based on these in silico analysis, the encoded
compound is predicted to be a chlorinated lipopeptide with nine amino acid residues.
Triangles represent the positions of the single disruptions in the thaAB and thaCD gene
clusters obtained by either random (white triangle) or site-directed mutagenesis (black
triangle). (B) In vitro hyphal growth inhibition of R. solani by Pseudomonas sp. strain
A TCl
C AT C A
T C AT C A
T C A T C AT C A T C A T C TE
TC
module 2 module 4module 7
5 kb
thaC1
thaC2
module 9module 9module 1 module 3 module 5module 6 module 8
thaA
Ser ? Asp/Glu ? ? Thr Thr Asp/Glu Thr
Cl
O33
thaB
thaD
SH-C52
KO26O33
KO25 KO26
A
B
14
SH-C52 and its respective mutants O33 and KO26. The mutant KO25 showed the same
lack of in vitro activity as O33. Disruption of the thaB or thaC2 genes largely eliminated
the antifungal activity of strain SH-C52, which can be observed by the significantly
smaller inhibition zones of these mutants in comparison with the inhibition caused by
parental strain SH-C52.
15
Table S1. Physical and chemical properties of the disease suppressive and conducive
soils obtained from Hoeven, The Netherlands. Both soils were classified as sandy soils
based on analyses performed by BLGG-AgroXpertus (Oosterbeek, The Netherlands).
Suppressive soil Conducive soil
Chemical analysis
pH 5.8 5.6
Organic matter (%) 2.9 2.7
CaCO3 (%) < 0.1 < 0.1
----- mg kg-1
-----
NH4 4.5 10.2
NO3 17.6 1.7
P 3.2 2.5
K 93.0 69.0
Mg 37.0 30.0
Na 20.0 <6.0
Mn <0.25 0.62
----- µg kg-1
-----
Cu 42 38
Co <2.5 7.2
B 109 97
Zn 272 2446
Particle diameter (µm) ----- % -----
0-2 2.5 1.4
2-16 3.4 2.0
16-50 7.5 6.5
50-105 18.9 17.0
105-150 20.7 21.4
150-210 25.5 26.1
210-300 16.3 17.8
300-420 4.1 5.3
420-600 0.8 1.6
600-2000 0.4 0.9
M50 median particles size 159 165
16
Table S2. Fresh weight (N=4) of sugar beet seedlings grown in suppressive soil and
conducive soil in the absence of the pathogen R. solani. No significant differences were
observed between the two treatments (P<0.05, Student’s t-test).
Soil Fresh weight (mg) (±SD)
Suppressive 202 (±49)
Conducive 256 (±38)
17
Table S3. The top 10% most dynamic subset of the rhizosphere microbiome that meets
all of the following criteria: i) more abundant in suppressive than in conducive soil, ii)
more abundant in the ‘transplantation soil’ (conducive soil + 10% suppressive soil) than
in the conducive soil, and iii) more abundant in the suppressive soil when the fungal
pathogen R. solani is present.
Phylum Affiliation
Representative OTU sequence
GenBank accession
Clone / strain
Proteobacteria Pseudomonadaceae EU538127 antecubital fossa skin clone nbt82e01
EU434358 Pseudomonas libanensis strain a110
EU537608 antecubital fossa skin clone nbt74g09
EU434526 Pseudomonas fluorescens strain b339
EU535118 antecubital fossa skin clone nbt171b09
Burkholderiaceae AY550913 Burkholderia sp. FDS-1
AY439198 soil clone MeBr 20
AY321306 Burkholderia tropica LM2-37603
AY326592 Amazon soil clone 141-1
AB299578 Burkholderia sp. 70-VN5-1W
AY439195 soil clone MeBr 1
AY178068 Burkholderia sp. UCT 15
AF408946 Burkholderia sp. Ellin104
AB079372 Burkholderia sp. S-2
Xanthomonadales L76222 Rhodanobacter lindaniclasticus
AY218744 penguin droppings clone KD5-94
Firmicutes Lactobacillaceae EF096273 mouse cecum clone obob1_aaa03h11
18
Table S4. Frequency of antagonistic bacteria isolated from the rhizosphere of sugar beet
plants grown in disease suppressive or conducive soil. Bacteria were isolated on a general
aerobic growth medium (TSA) and on a medium semi-selective for members of the
Pseudomonadaceae. For each soil 200 - 300 isolates were randomly selected and tested
for their ability to inhibit mycelial growth of the fungal pathogen Rhizoctonia solani in
vitro. Isolates that inhibit mycelial growth were classified as antagonistic.
Soil type Replicate Aerobic medium Pseudomonas medium
antagonistic§ % antagonistic
§ %
Suppressive 1 4/96 4.2 39/96 40.6
2 3/96 3.1 42/96 43.8
3 0/96 0.0 23/96 24.0
Total 7/288 2.4 104/288 36.1
Conducive 1 4/76 5.3 0/78 0.0
2 3/38 7.9 1/81 1.2
3 4/75 5.3 2/73 2.8
Total 11/189 5.8 3/232 1.3
§ Number of antagonistic isolates / total number of tested isolates.
19
Table S5. Sequence identities of the 16S rDNA genes of the ten bacterial groups
(haplotypes SH-A to SH-J) from the disease suppressive soil with the 16S rDNA genes
present on the PhyloChip. The data shown represent the best BLAST hits of 16S rDNA
sequences present in the PhyloChip database (GreenGenes).
Haplotype* Hit in the BLAST
search†
GenBank accession
Score Identity
(%) Haplotype
cluster
SH-A Pseudomonas sp. HNR09 EU373356 1352 99.78 I
SH-B Pseudomonas sp. A1Y13 AY512624 1355 99.93 II
SH-C Pseudomonas sp. HNR09 EU373356 1354 99.85 I
SH-D Pseudomonas sp. HNR09 EU373356 1354 99.85 I
SH-E Pseudomonas sp. HNR09 EU373356 1354 99.85 I
SH-F Pseudomonas sp. BIHB 811 DQ885950 1349 99.71 III
SH-G Pseudomonas sp. BIHB 811 DQ885950 1349 99.71 III
SH-H Pseudomonas sp. HNR09 EU373356 1352 99.78 I
SH-I Pseudomonas sp. HNR09 EU373356 1352 99.78 I
SH-J Pseudomonas sp. HNR09 EU373356 1354 99.85 I
* or BOX-PCR group
† greengenes.lbl.gov/cgi-bin/nph-blast_interface.cgi
20
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