Perception and Transduction of Plant Signals in Pathogens

2007 ◽  
Keyword(s):  
Plant Signals

scholarly journals LuxR- and LuxI-Type Quorum-Sensing Circuits Are Prevalent in Members of the Populus deltoides Microbiome

2013 ◽  
Vol 79 (18) ◽  
pp. 5745-5752 ◽  
Author(s):  
Amy L. Schaefer ◽  
Colin R. Lappala ◽  
Ryan P. Morlen ◽  
Dale A. Pelletier ◽  
Tse-Yuan S. Lu ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Populus Deltoides ◽  
Cell Communication ◽  
Homoserine Lactone ◽  
Bacterial Isolates ◽  
Content Type ◽  
Eastern Cottonwood ◽  
Bacterial Signaling ◽  
Signal Production ◽  
Plant Signals

ABSTRACTWe are interested in the root microbiome of the fast-growing Eastern cottonwood tree,Populus deltoides. There is a large bank of bacterial isolates fromP. deltoides, and there are 44 draft genomes of bacterial endophyte and rhizosphere isolates. As a first step in efforts to understand the roles of bacterial communication and plant-bacterial signaling inP. deltoides, we focused on the prevalence of acyl-homoserine lactone (AHL) quorum-sensing-signal production and reception in members of theP. deltoidesmicrobiome. We screened 129 bacterial isolates for AHL production using a broad-spectrum bioassay that responds to many but not all AHLs, and we queried the available genome sequences of microbiome isolates for homologs of AHL synthase and receptor genes. AHL signal production was detected in 40% of 129 strains tested. Positive isolates included members of theAlpha-,Beta-, andGammaproteobacteria. Members of theluxIfamily of AHL synthases were identified in 18 of 39 proteobacterial genomes, including genomes of some isolates that tested negative in the bioassay. Members of theluxRfamily of transcription factors, which includes AHL-responsive factors, were more abundant thanluxIhomologs. There were 72 in the 39 proteobacterial genomes. Some of theluxRhomologs appear to be members of a subfamily of LuxRs that respond to as-yet-unknown plant signals rather than bacterial AHLs. Apparently, there is a substantial capacity for AHL cell-to-cell communication in proteobacteria of theP. deltoidesmicrobiota, and there are alsoProteobacteriawith LuxR homologs of the type hypothesized to respond to plant signals or cues.

Plant signals

Science ◽  
1996 ◽  
Vol 274 (5289) ◽  
pp. 893.8-0
Keyword(s):  
Plant Signals

scholarly journals Cry-wolf signals emerging from coevolutionary feedbacks in a tritrophic system

2015 ◽  
Vol 282 (1818) ◽  
pp. 20152169 ◽  
Author(s):  
Atsushi Yamauchi ◽  
Minus van Baalen ◽  
Yutaka Kobayashi ◽  
Junji Takabayashi ◽  
Kaori Shiojiri ◽  
...  
Keyword(s):  
Communication Systems ◽  
Feedback Loops ◽  
Tritrophic System ◽  
Evolution Of Communication ◽  
Herbivore Induced Plant Volatiles ◽  
Plant Signals ◽  
Selection For ◽  
The Stability ◽  
Plant Herbivore ◽  
Heavy Damage

For a communication system to be stable, senders should convey honest information. Providing dishonest information, however, can be advantageous to senders, which imposes a constraint on the evolution of communication systems. Beyond single populations and bitrophic systems, one may ask whether stable communication systems can evolve in multitrophic systems. Consider cross-species signalling where herbivore-induced plant volatiles (HIPVs) attract predators to reduce the damage from arthropod herbivores. Such plant signals may be honest and help predators to identify profitable prey/plant types via HIPV composition and to assess prey density via the amount of HIPVs. There could be selection for dishonest signals that attract predators for protection from possible future herbivory. Recently, we described a case in which plants release a fixed, high amount of HIPVs independent of herbivore load, adopting what we labelled a ‘cry-wolf’ strategy. To understand when such signals evolve, we model coevolutionary interactions between plants, herbivores and predators, and show that both ‘honest’ and ‘cry-wolf’ types can emerge, depending on the assumed plant–herbivore encounter rates and herbivore population density. It is suggested that the ‘cry-wolf’ strategy may have evolved to reduce the risk of heavy damage in the future. Our model suggests that eco-evolutionary feedback loops involving a third species may have important consequences for the stability of this outcome.

scholarly journals RIVET—A Tool for In Vivo Analysis of Symbiotically Relevant Gene Expression in Sinorhizobium meliloti

2008 ◽  
Vol 21 (2) ◽  
pp. 162-170 ◽  
Author(s):  
Mengsheng Gao ◽  
Max Teplitski
Keyword(s):  
Gene Regulation ◽  
Sinorhizobium Meliloti ◽  
Homoserine Lactone ◽  
Symbiotic Gene ◽  
Gus Reporter ◽  
In Vivo Analysis ◽  
Plant Signals ◽  
Relevant Gene

Despite significant advances in the development of sensitive tools for studying genetics and signal exchange in legume–rhizobium symbioses, many uncertainties remain about the in vivo role of bacterial and plant signals in symbiotic gene regulation. In this study, we adapted TnpR recombinase-based in vivo expression technology (RIVET) to document gene regulation in Sinorhizobium meliloti. The substrate for TnpR, the res1-tet-res1 cassette, is stably inherited when cloned into a neutral site of the S. meliloti genome. Bicistronic promoterless tnpR-β-glucuronidase (GUS) reporters were constructed to track expression (“resolution”) of symbiotically relevant S. meliloti genes during different stages of the interaction. In proof of principle experiments, the resolution of the nodC::tnpR reporter was detected within 4 h of exposure to micromolar levels of the nod operon inducer luteolin and after overnight incubation in the rhizosphere. RIVET demonstrated that cell division gene ftsZ2 was not strongly expressed in the rhizosphere but was activated inside the nodules and on agar surfaces. Rhizosphere expression of the N-acyl homoserine lactone (AHL) synthase sinI::tnpR-GUS reporter was modest in prequorate microcolonies, and then increased with time. AHL synthase sinI and an AHL-regulated gene, expG, were activated inside the nodules.

scholarly journals Transcriptional Responses in the Hemiparasitic PlantTriphysaria versicolor to Host Plant Signals

2001 ◽  
Vol 127 (1) ◽  
pp. 272-282 ◽  
Author(s):  
Marta Matvienko ◽  
Manuel J. Torres ◽  
John I. Yoder
Keyword(s):  
Host Plant ◽  
Transcriptional Responses ◽  
Plant Signals

scholarly journals Different Regulation and Roles of Lactonases AiiB and AttM in Agrobacterium tumefaciens C58

2009 ◽  
Vol 22 (5) ◽  
pp. 529-537 ◽  
Author(s):  
Elise Haudecoeur ◽  
Mélanie Tannières ◽  
Amélie Cirou ◽  
Aurélie Raffoux ◽  
Yves Dessaux ◽  
...  
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Selective Advantage ◽  
In Planta ◽  
Host Interaction ◽  
Plant Tumors ◽  
Plant Signals ◽  
Polymerase Chain ◽  
Agrobacterium Tumefaciens C58 ◽  
Regulated Functions

The phytopathogen Agrobacterium tumefaciens C58 expresses two lactonases, AttM and AiiB. We showed that expression of the aiiB gene was controlled by agrocinopines A and B and required the agrocinopine-ABC transporter Acc, but was not affected by the level of quorum-sensing (QS) signal 3-oxo-octanoylhomoserine lactone (OC8-HSL). In the presence of agrocinopines, a constructed aiiB mutant accumulated OC8-HSL at a level 10-fold higher than that of the wild-type strain, and showed an exacerbated expression of a key QS-regulated function, conjugation of Ti plasmid (in vitro and in planta), as well as an increase of the number of emerging tumors on the host plant. The expression and acyl-HSL-degrading activity of AttM were evident in the presence of wounded tissues; however, in unwounded plant tumors, the QS-regulated functions were weakly affected in an attM mutant. By contrast, we observed that attM conferred a selective advantage in the course of colonization of plant tumors. Finally, polymerase chain reaction survey of genes attM and aiiB showed that they were not strictly conserved in the genus Agrobacterium. This work proved that the lactonases AttM and AiiB are regulated by different plant signals and are implicated in different functions in the course of the A. tumefaciens C58–host interaction.

scholarly journals Constraints on plant signals and rewards to multiple mutualists?

2009 ◽  
Vol 4 (9) ◽  
pp. 801-804 ◽  
Author(s):  
Kenneth D. Whitney ◽  
Jennifer A. Rudgers
Keyword(s):  
Plant Signals

scholarly journals ASSAYS TO DETERMINE CHERRY ROOTSTOCK TOLERANCE TO “BACTERIAL CANKER” (PSEUDOMONAS SYRINGAE PV. SYRINGAE)

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1123f-1123
Author(s):  
Elzbieta Krzesinska ◽  
Anita Nina Miller
Keyword(s):  
Pseudomonas Syringae ◽  
Virulence Genes ◽  
Avirulent Strain ◽  
Bacterial Canker ◽  
Aqueous Extracts ◽  
Virulent Strains ◽  
Plant Signals ◽  
One Year

An excised twig assay was developed to evaluate cherry genotypes for their tolerance to Pseudomonas syringae pv. syringae. One-year-old wood was collected at monthly intervals from Oct. until Jan. of `Napoleon', `Corum', and a number of cherry rootstock. The rootstock included F/12-1, Giessen (GI), and M×M selections. Twigs were inoculated with one avirulent and three virulent strains. Evaluation of incision browning, callus, and gummosis production were made after incubation for 3 weeks. Based on gummosis is and browning ratings, all the rootstocks tested were found to be more tolerant than `Napoleon' and `Corum' to the 3 strains of Pseudomonas syringae used. No gummosis or browning was observed on twigs inoculated with water or the avirulent strain.Plant signals extracted from cherry leaves have been shown to control expression of virulence genes in P. syringae. Crude aqueous extracts from `Napoleon' twigs induced the syrB::1acZ fusion in P. syringae strain B3AR132 Other rootstocks are currently being evaluated for their ability to induce virulence in P. syringae pv. syringae,

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