Characterization and Function of Avirulence Genes from Pseudomonas Syringae pv. Tomato

1989 ◽  
pp. 183-188 ◽  
Author(s):  
N. T. Keen ◽  
S. Tamaki ◽  
D. Kobayashi ◽  
M. Stayton ◽  
D. Gerhold ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Avirulence Genes ◽  
And Function

scholarly journals Pseudomonas syringae Phytotoxins: Mode of Action, Regulation, and Biosynthesis by Peptide and Polyketide Synthetases

1999 ◽  
Vol 63 (2) ◽  
pp. 266-292 ◽  
Author(s):  
Carol L. Bender ◽  
Francisco Alarcón-Chaidez ◽  
Dennis C. Gross
Keyword(s):  
Pseudomonas Syringae ◽  
Plasma Membranes ◽  
Antimicrobial Agents ◽  
Gene Clusters ◽  
Regulatory Genes ◽  
Signal Molecules ◽  
Peptide Synthetases ◽  
Biological Stress ◽  
Regulatory Circuits ◽  
And Function

SUMMARY Coronatine, syringomycin, syringopeptin, tabtoxin, and phaseolotoxin are the most intensively studied phytotoxins of Pseudomonas syringae, and each contributes significantly to bacterial virulence in plants. Coronatine functions partly as a mimic of methyl jasmonate, a hormone synthesized by plants undergoing biological stress. Syringomycin and syringopeptin form pores in plasma membranes, a process that leads to electrolyte leakage. Tabtoxin and phaseolotoxin are strongly antimicrobial and function by inhibiting glutamine synthetase and ornithine carbamoyltransferase, respectively. Genetic analysis has revealed the mechanisms responsible for toxin biosynthesis. Coronatine biosynthesis requires the cooperation of polyketide and peptide synthetases for the assembly of the coronafacic and coronamic acid moieties, respectively. Tabtoxin is derived from the lysine biosynthetic pathway, whereas syringomycin, syringopeptin, and phaseolotoxin biosynthesis requires peptide synthetases. Activation of phytotoxin synthesis is controlled by diverse environmental factors including plant signal molecules and temperature. Genes involved in the regulation of phytotoxin synthesis have been located within the coronatine and syringomycin gene clusters; however, additional regulatory genes are required for the synthesis of these and other phytotoxins. Global regulatory genes such as gacS modulate phytotoxin production in certain pathovars, indicating the complexity of the regulatory circuits controlling phytotoxin synthesis. The coronatine and syringomycin gene clusters have been intensively characterized and show potential for constructing modified polyketides and peptides. Genetic reprogramming of peptide and polyketide synthetases has been successful, and portions of the coronatine and syringomycin gene clusters could be valuable resources in developing new antimicrobial agents.

scholarly journals Pseudomonas syringae Effector avrB Confers Soybean Cultivar-Specific Avirulence on Soybean mosaic virus Adapted for Transgene Expression but Effector avrPto Does Not

2006 ◽  
Vol 19 (3) ◽  
pp. 304-312 ◽  
Author(s):  
Li Wang ◽  
Alan Eggenberger ◽  
John Hill ◽  
Adam J. Bogdanove
Keyword(s):  
Mosaic Virus ◽  
Pseudomonas Syringae ◽  
Transgene Expression ◽  
Fluorescent Protein ◽  
Soybean Mosaic Virus ◽  
Hypersensitive Reaction ◽  
Green Fluorescent Protein Gene ◽  
Avirulence Genes ◽  
Pathogenesis Related Protein ◽  
Viral Movement

Soybean mosaic virus (SMV) was adapted for transgene expression in soybean and used to examine the function of avirulence genes avrB and avrPto of Pseudomonas syringae pvs. glycinea and tomato, respectively. A cloning site was introduced between the P1 and HC-Pro genes in 35S-driven infectious cDNAs of strains SMV-N and SMV-G7. Insertion of the uidA gene or the green fluorescent protein gene into either modified cDNA and bombardment into primary leaves resulted in systemic expression that reflected the pattern of viral movement into uninoculated leaves. Insertion of avrB blocked symptom development and detectable viral movement in cv. Harosoy, which carries the Rpg1-b resistance gene corresponding to avrB, but not in cvs. Keburi or Hurrelbrink, which lack Rpg1-b. In Keburi and Hurrelbrink, symptoms caused by SMV carrying avrB appeared more quickly and were more severe than those caused by the virus without avrB. Insertion of avrPto enhanced symptoms in Harosoy, Hurrelbrink, and Keburi. This result was unexpected because avrPto was reported to confer avirulence on P. syringae pv. glycinea inoculated to Harosoy. We inoculated Harosoy with P. syringae pv. glycinea expressing avrPto, but observed no hypersensitive reaction, avrPto-dependent induction of pathogenesis-related protein 1a, or limitation of bacterial population growth. In Hurrelbrink, avrPto enhanced bacterial multiplication and exacerbated symptoms. Our results establish SMV as an expression vector for soybean. They demonstrate that resistance triggered by avrB is effective against SMV, and that avrB and avrPto have general virulence effects in soybean. The results also led to a reevaluation of the reported avirulence activity of avrPto in this plant.

scholarly journals A 2′-O-Methyltransferase Responsible for Transfer RNA Anticodon Modification Is Pivotal for Resistance to Pseudomonas syringae DC3000 in Arabidopsis

2018 ◽  
Vol 31 (12) ◽  
pp. 1323-1336 ◽  
Author(s):  
Vicente Ramírez ◽  
Beatriz González ◽  
Ana López ◽  
Maria Jose Castelló ◽  
Maria José Gil ◽  
...  
Keyword(s):  
Disease Resistance ◽  
Pseudomonas Syringae ◽  
Bacterial Pathogen ◽  
Transfer Rna ◽  
Resistance Response ◽  
Chemical Structures ◽  
Trna Modifications ◽  
Trna Species ◽  
Living Organisms ◽  
And Function

Transfer RNA (tRNA) is the most highly modified class of RNA species in all living organisms. Recent discoveries have revealed unprecedented complexity in the tRNA chemical structures, modification patterns, regulation, and function, suggesting that each modified nucleoside in tRNA may have its own specific function. However, in plants, our knowledge of the role of individual tRNA modifications and how they are regulated is very limited. In a genetic screen designed to identify factors regulating disease resistance in Arabidopsis, we identified SUPPRESSOR OF CSB3 9 (SCS9). Our results reveal SCS9 encodes a tRNA methyltransferase that mediates the 2′-O-ribose methylation of selected tRNA species in the anticodon loop. These SCS9-mediated tRNA modifications enhance susceptibility during infection with the virulent bacterial pathogen Pseudomonas syringae DC3000. Lack of such tRNA modification, as observed in scs9 mutants, specifically dampens plant resistance against DC3000 without compromising the activation of the salicylic acid signaling pathway or the resistance to other biotrophic pathogens. Our results support a model that gives importance to the control of certain tRNA modifications for mounting an effective disease resistance in Arabidopsis toward DC3000 and, therefore, expands the repertoire of molecular components essential for an efficient disease resistance response.

Organization, regulation and function of Pseudomonas syringae pv. syringae hrp genes

1994 ◽  
pp. 593-603 ◽  
Author(s):  
Steven W. Hutcheson ◽  
Sunggi Heu ◽  
Hsiou-Chen Huang ◽  
Michael C. Lidell ◽  
Yingxian Xiao
Keyword(s):  
Pseudomonas Syringae ◽  
Hrp Genes ◽  
And Function

Isolation of Novel Avirulence Genes from Pseudomonas syringae pv. pisi

2001 ◽  
pp. 216-219
Author(s):  
D. L. Arnold ◽  
R. W. Jackson ◽  
A. Vivian
Keyword(s):  
Pseudomonas Syringae ◽  
Avirulence Genes

The epidemiology and management of bacterial blight (Pseudomonas syringae pv. pisi) of field pea (Pisum sativum) in Australia: a review

2007 ◽  
Vol 58 (11) ◽  
pp. 1086 ◽  
Author(s):  
G. J. Hollaway ◽  
T. W. Bretag ◽  
T. V. Price
Keyword(s):  
Pisum Sativum ◽  
Pseudomonas Syringae ◽  
Bacterial Blight ◽  
Weather Conditions ◽  
Frost Damage ◽  
Field Pea ◽  
Crop Damage ◽  
Avirulence Genes ◽  
Race 2 ◽  
Sowing Seed

Bacterial blight caused by Pseudomonas syringae pv. pisi is an important, but sporadic, disease of field peas (Pisum sativum) in Australia. The presence of P. syringae pv. pisi reduces the profitability of peas due to yield loss and, in some cases, it also limits Australia’s export of peas to some countries. Pseudomonoas syringae pv. pisi is primarily a seed-borne pathogen, but infected pea trash can be an important source of inoculum. Alternative hosts and soil are not regarded as epidemiologically important sources of inoculum. P. syringae pv. pisi survives, multiplies and spreads epiphytically in pea crops. Epiphytic populations of P. syringae pv. pisi only become pathogenic following crop damage caused by frost or severe weather conditions. Frost damage is especially important because the ice nucleating activity of P. syringae pv. pisi initiates frost damage at higher temperatures than occurs in the absence of the bacterium. In addition early-sown crops are more prone to damage from bacterial blight than crops sown later in the season. Pseudomonas syringae pv. pisi consists of seven identified races. One of these (Race 6) lacks all avirulence genes and is common around the world and in Australia. Globally, Race 2 and Race 6 predominate; however, in Australia, Race 3 predominates due to the widespread cultivation of cultivars susceptible to Race 3, but resistant to Race 2. Resistance to Race 6 within P. sativum has not been found but attempts are being made to incorporate a race non-specific resistance identified from P. abyssinicum into field pea. Bacterial blight can be successfully controlled using an integrated disease management strategy incorporating crop rotation, pathogen-free seed, avoidance of planting in areas prone to frequent frosts or extreme wet weather, crop hygiene and avoiding early sowing. Seed treatment and application of foliar bactericides have limited use in control of this disease.

Avirulence genes from Pseudomonas syringae pathovars phaseolicola and pisi confer specificity towards both host and non-host species

1992 ◽  
Vol 40 (1) ◽  
pp. 1-15 ◽  
Author(s):  
A.J. Fillingham ◽  
J. Wood ◽  
J.R. Bevan ◽  
I.R. Crute ◽  
J.W. Mansfield ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Host Species ◽  
Avirulence Genes ◽  
Pseudomonas Syringae Pathovars

scholarly journals In Planta Effector Competition Assays Detect Hyaloperonospora arabidopsidis Effectors That Contribute to Virulence and Localize to Different Plant Subcellular Compartments

2013 ◽  
Vol 26 (7) ◽  
pp. 745-757 ◽  
Author(s):  
Jorge Luis Badel ◽  
Sophie J. M. Piquerez ◽  
David Greenshields ◽  
Ghanasyam Rallapalli ◽  
Georgina Fabro ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Bacterial Population ◽  
Molecular Probes ◽  
Avirulence Genes ◽  
In Planta ◽  
Mixed Inoculum ◽  
Subcellular Compartments ◽  
Molecular Pattern ◽  
Hyaloperonospora Arabidopsidis ◽  
Competition Assays

The genome of the pathogenic oomycete Hyaloperonospora arabidopsidis is predicted to encode at least 134 high-confidence effectors (HaRxL) carrying the RxLR motif implicated in their translocation into plant cells. However, only four avirulence genes (ATR1, ATR13, ATR5, and ATR39) have been isolated. This indicates that identification of HaRxL effectors based on avirulence is low throughput. We aimed at rapidly identifying H. arabidopsidis effectors that contribute to virulence by developing methods to detect and quantify multiple candidates in bacterial mixed infections using either Illumina sequencing or capillary electrophoresis. In these assays, referred to here as in planta effector competition assays, we estimate the contribution to virulence of individual effectors by calculating the abundance of each HaRxL in the bacterial population recovered from leaves 3 days after inoculation relative to abundance in the initial mixed inoculum. We identified HaRxL that enhance Pseudomonas syringae pv. tomato DC3000 growth in some but not all Arabidopsis accessions. Further analysis showed that HaRxLL464, HaRxL75, HaRxL22, HaRxLL441, and HaRxL89 suppress pathogen-associated molecular pattern-triggered immunity (PTI) and localize to different subcellular compartments in Nicotiana benthamiana, providing evidence for a multilayered suppression of PTI by pathogenic oomycetes and molecular probes for the dissection of PTI.

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