Friend or foe: genetic and functional characterization of plant endophytic Pseudomonas aeruginosa
Article first published online: 22 NOV 2012
© 2012 Society for Applied Microbiology and Blackwell Publishing Ltd
Special Issue: Plant–Microbe Interactions
Volume 15, Issue 3, pages 764–779, March 2013
How to Cite
Kumar, A., Munder, A., Aravind, R., Eapen, S. J., Tümmler, B. and Raaijmakers, J. M. (2013), Friend or foe: genetic and functional characterization of plant endophytic Pseudomonas aeruginosa. Environmental Microbiology, 15: 764–779. doi: 10.1111/1462-2920.12031
- Issue published online: 4 MAR 2013
- Article first published online: 22 NOV 2012
- Accepted manuscript online: 26 OCT 2012 06:13AM EST
- Manuscript Accepted: 19 OCT 2012
- Manuscript Revised: 16 OCT 2012
- Manuscript Received: 5 SEP 2012
Fig. S1. Ascending endophytic colonization of PaBP35 in rooted cuttings of Piper nigrum. Pre-planting bacterization (OD600: 1.0) was carried out in roots for varying duration.
A. Each bar represents population size of PaBP35 in black pepper plant parts (1.0 g) excised from bacterized rooted cutting. LSD (P = 0.05): 0.113. Error bar indicates standard error.
B. Each lane represents PCR amplification of DNA (560 bp) extracted from black pepper plant parts, viz. roots, stem and leaf, excised from bacterized rooted cutting after various duration (0, 30, 60, 120 h) of bacterization. Each gel image represents 0, 7, 14, 21 and 28 days' samples.
*DPT, days post transplanting.
Fig. S2. A. Swarming motility of P. aeruginosa strain PaBP35 on KMB soft (0.6% w/v) agar. Cell suspension of strain PaBP35 were spot-inoculated (10 μl) in the centre of the soft agar plates and incubated at 25°C (Petri plate on left) and at 37°C (Petri plate on right) for 18 h.
B. Mycelial inhibition of P. capsici LT3229 by PaBP35 (Petri plate on right); control plate (Petri plate on left) did not show any inhibition.
C. RP-HPLC chromatogram at 367 nm of a cell free culture extract of PaBP35.
D. Spectral characteristics of the peak at RT 19.8 min as compared with the spectral characteristics of a pure phenazine standard (phenazine-1-carboxylic acid).
E. Gel picture with PCR products amplified from genomic DNA of P. aeruginosa strains PaBP35 and PAO1 with primers specific for the phenazine (phz) gene.
F. Inhibition of hyphal growth of P. capsici by phenazine-containing MeOH extracts of cell free culture filtrate of PaBP35; MeOH-spotted plate did not show any growth inhibition (Petri plate on left) whereas phenazine-spotted plate showed concentration-dependent inhibition of mycelium (Petri plate on right). Each paper disk was spotted with 0, 5, 10 and 20 μl of MeOH extract containing phenazine.
Fig. S3. A. Secretion of surfactants by P. aeruginosa strain PaBP35 on SW medium.
B. Zoosporicidal (P. capsici) activity of surfactants extracted from culture filtrates of PaBP35.
C. PCR amplification of two rhamnolipid biosynthesis genes, rhlA and rhlC, in PaBP35.
D. PCR amplification of two regulatory genes of rhamnolipid biosynthesis, rhlI and rhlR, in PaBP35. For PCR-based detection, P. aeruginosa strain PAO1 was used as a reference.
Fig. S4. Neighbour-joining phylogenetic tree of 1180 bp recN sequences from multiple Pseudomonas species and strains from diverse habitats. The phylogenetic tree was generated with the minimum evolution method using maximum composite likelihood model in Mega 5.01 program (Tamura et al., 2011). Azotobacter vinelandi served as an outgroup in the analysis. Numbers on the nodal support represents bootstrap values (1000 resamplings). • P. aeruginosa from plant habitat; ▴ P. aeruginosa from clinical habitats.
Fig. S5. eBurst diagram of P. aeruginosa isolates from multiple habitats including strain PaBP35 (indicated as BP35). The strain relatedness was calculated based on core genome SNPs and presence of two multi-allele loci, FliCa or FliCb and ExoS or ExoU.
Please note: Wiley Blackwell is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.