an aldehyde dehydrogenase gene and a phosphinothricin n ... · bacterial rot of lettuce necrotic...
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Bacterial rot of lettuce Necrotic leaf spot of eggplant
An aldehyde dehydrogenase gene and a phosphinothricin n-acetyltransferase gene compose of a pathogenicity island with hrp genes of Pseudomonas cichirii
Y. Hikichi, M. Tanaka, U. Md. Wali, H. Mizumoto, K. Ohnishi and A. Kiba
hrp genes of Pseudomonas cichorii strain SPC9018
The consensus hrp-box ( , GGAACC-N15-16-CCANNCA) was identified at putative promoters of hrpA, hrpF, hrpW, avrE, avrF and hrpJ.
Hojo et al. Microbiology, 2008
hrcT mutant
SPC9018
hrpG mutant
hrpS mutant
hrpL mutant
DW
hrcT mutant
SPC9018
hrpG mutant
hrpS mutant
hrpL mutant
DW
eggplant lettuce
Hojo et al. Microbiology, 2008
Virulence of P. cichorii strain SPC9018 on eggplant and lettuce
The hrp mutants of SPC9018 lost their virulence on eggplant 1 days after inoculation
P. syringae type
P. cichorii type
T-PAI S-PAI
Araki et al. PNAS, 2006
Nucleotide sequences of the hrp genes of SPC9018 and their genetic structure werehomologous to those of S-PAI of P. viridiflava BS group strains.
Pathogenicity island and hrp cluster of P. viridiflava
Virulence of the hrpG mutant on eggplant was restored by transformation with ahrpF operon, originating from Pv9504, suggesting that functional conservation of hrpFoperons between SPC9018 and Pv9504 .
hrcT mutant
SPC9018
hrpG mutant
hrpS mutant
hrpL mutant
hrpG mutant (phrpFPc)
DW
hrpG mutant (phrpFPv)
eggplant
Complementation of hrpG mutant with hrpF operon from a BS group member P. viridiflava strain 9504 (Pv9504)
eggplant
Hojo et al. Microbiology, 2008
The hrp is involved in full virulence of P. cichorii on eggplant and lettuce
Hojo et al. Microbiology, 2008
hrcT mutant
hrpG mutant
hrpS mutant
hrcTmutant
hrpL mutant
Transformant ofhrpG mutant with hrpF operon
P. viridiflava strain 9504 (BS group, Pv9504)
P. cichorii strain SPC9018
phosphinorthiricin N-acetyltransferase (pat)
LysR family transcriptional regulator(lysR)
hrpL hrpJ
hrpL hrpJ
phosphinorthiricin N-acetyltransferase (bar)
An aldehyde dehydrogenase gene (aldh) and a phosphinorthiricin N-acetyltransferasegene (pat) are located adjacent to hrpL of SPC9018 and Pv9504.
aldehyde dehydrogenase (aldH)
hrp cluster region A11.3-k bp
J V Q N Q R T UOP SL
LysR-typeTranscription regulator
aldH
Phosphinothricin N-acetyltransferase (pat)
hrpL
Phosphinothricin N-acetyltransferase
(bar)
LysR-typeTranscription regulator
aldH
ISPsy7, transposase
Phosphinothricin N-acetyltransferase (bar)
P. cichorii
P. syringae pv. tomato strain DC3000
The aldH but not the pat in the genome of P. cichorii and the S-PAI of P. viridiflavais located in the same positions of the genome of P. syringae strains and T-PAI of P. viridiflava.
SPC9018
ΔaldHΔpat
SPC9018SPC9018
ΔaldH
Δpat
ΔaldH (Pc-aldH)
Δpat (Pc-pat)
DW DW DW
eggplant lettuce
The aldH and pat was involved in virulence of P. cichorii strain SPC9018 on eggplant but not on lettuce.
Virulence of aldH-deficient mutant (ΔaldH) and pat-deficient mutant (Δpat) on eggplant and lettuce
SPC9018
ΔaldH
ΔaldH (Pc-aldH)
DW
eggplant
ΔaldH (Pv-aldH)
ΔaldH (Pst-aldH)
ΔaldH (Pa-aldH)
Function of aldH is conserved among these Pseudomonad.
Complementation of ΔaldH with aldH from P. viridiflava 9504, P. syringae pv.tomato strain DC3000 and P. aeruginosa strain PAO1
Δpat
SPC9018
Δpat (Pc-pat)
DW
Δpat (Pv-pat)
Complementation of Δpat with pat from P. viridiflava 9504
eggplant
Function of pat is conserved between P. cichorii SPC9018 and P. viridiflava 9504.
Expression analysis on hrpL, aldH and pat in SPC9018, ΔaldH, Δpat and hrpL-mutant (SPC9018-L) in infected leaves of eggplant by RT-PCR analysis
Expression of aldH and pat was not regulated by HrpL. Deletion of aldH and pat did not influence expression of hrpL. These results suggest that expression of aldH and pat is regulated independently of hrp regulo
Conclusion
1. An aldehyde dehydrogenase gene (aldH) and a phosphinothricin N-acetyltransferase gene (pat) are located in the flanking regions of the hrp innot only P. cichorii but also the BS and AS groups of P. viridiflava strainsharboring S-PAI .
2. Both aldH and pat are involved in P. cichorii virulence on eggplant but notlettuce.
3. The aldH is functionally conserved among Pseudomonad.4. The pat is functionally conserved between P. cichorii and the S-PAI.5. Expression of aldH and pat in P. cichorii infecting eggplant is independently
of that of hrpL.6. These results lead us to consider that P. cichorii may implicate not only the
hrp but also aldH and pat in its virulence.
Acknowledgement
Kobe UniversityProf. Shigeyuki MayamaProf. Pyoyun ParkProf. Yukio TosaDr. Nakayashiki
Sun Yat-Sen UniversityDr. Nan Yao
Boyce Thompson Institute for Plant ResearchProf. Gregory B. Martin
NIVTSDr. Takashi Shirakawa
Found
Grants-in-Aid for Scientific Research from the Ministry of Education, Science, Sports and Culture, JapanThe Asahi Glass Foundation
Mr. Tanaka
Dr. KibaDr. Mizumoto
Mr.Wali
Prof. Ohnishi
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