Classification:

• This tree (7) shows the relationships between members of the genus Pseudomonas
• Member of P. syringae because it has 16S rRNA (4)
• Gram-negative, polar-flagellated rod-shaped bacteria (3)

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pic (2)

Natural History:

• The original strain was first isolated in 1902 by Van Hall from a diseased lilac (Syringa vulgaris) (6)
• This picture depicts the ability of the bacteria's surface proteins to induce ice crystal formation on plants at above-freezing temperatures (2)

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Habitat:

• Found in agricultural settings, precipitation(rain and snow), alpine streams/lakes, wild plants, epilithic biofilms from rivers outside of agricultural zones (5)
• Most strains live on (phyllosphere), therefore it is an epiphytic bacterium (6)
• Phyllosphere considered extreme environment for bacteria due to constantly changing conditions (6)
• Thrive in cool wet conditions: rain is essential to survival and transport to new hosts (6)
• Hot dry weather causes dramatic population decrease (6)

Metabolism:

• Aerobic metabolism (6)
• Chemoheterotrophic organisms that depend on host organism for nutrients (6)
• Nutritionally versatile: thrives on damaged plant tissues and colonizes the surface of plant leaves (6)
• Get nutrients from those that diffuse onto leaf surface (6)
• Can also live as saprophytes (live off dead organic material) when conditions are not favorable for pathogenic existence (6)

Reproduction: 

• Reproduces by binary fission (10)
• The propagation pattern of these bacteria follows the water cycle; bacteria infect a plant via rainfall, then reproduce and are aerosolized into the atmosphere again (8)
  

Pathology: 

• Pseudomonas syringae is a plant pathogen, able to infect a wide range of plants species and exists as over 50 different pathovars (each is specific to a particular plant) (4)
• Produces Ina proteins that cause water to freeze at fairly high temperatures, causing injury to plants (4)
• Disease due to the bacteria is not merely due to its presence but its overpopulation on the surface of the host (6)
• Pathogenic strains enact disease symptoms by releasing toxins and enzymes that degrade cell walls (6)
• Adapts to unfavorable weather conditions by forming lesions on the host (these signify pathogenic activity) (6)
• As the bacteria flourishes in the host, it causes disease, lesions and frost damage; therefore leading to its own demise (6)
• Many strains are pathogenic but some are not and can be used as potential inoculations against the bacteria for some plants (6)

pic (9)

Conservation Status:

• Found in nature and in agricultural settings, not in any way endangered (5)

Interesting Facts: 

• Has ice nucleation properties:  produces surface proteins that are necessary to ice crystal formation at sub-zero temperatures on plant surfaces (6)

        -To prevent frost damage of cash crops, scientists can isolate and eliminate this surface protein gene
        -Ski resorts exploit these surface proteins to induce the creation of artificial snow