Location

University of Utah

Start Date

8-5-2000 10:00 AM

Description

Concerns about dramatic changes in the Earth’s atmosphere, such as ozone depletion, make it imperative to study how microbial communities are responding to such changes that will increase UV irradiance. Ultraviolet A (UVA) and UVB irradiation on the plant pathogen, Pseudomonas syringae pv syringae (Pss), and a plant beneficial, saprophytic root-colonizer, Pseudomonas putida (Pp) impaired their survival. Stationary-phase cells of both Pss and Pp were more susceptible to fatal UV damage than logarithmic-phase cells. This observation suggests that an active metabolism is involved in responses to protect against UV. Mutants of Pss and Pp, with insertions in rpoS, catA, and sodA and B, were all more severely affected by UV than the wild-types. These findings lead us to speculate that mechanisms to protect against oxidative stress are important in cell survival against UVA/B irradiation.

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May 8th, 10:00 AM

UV Effects of Plant-Associated Pseudomonads

University of Utah

Concerns about dramatic changes in the Earth’s atmosphere, such as ozone depletion, make it imperative to study how microbial communities are responding to such changes that will increase UV irradiance. Ultraviolet A (UVA) and UVB irradiation on the plant pathogen, Pseudomonas syringae pv syringae (Pss), and a plant beneficial, saprophytic root-colonizer, Pseudomonas putida (Pp) impaired their survival. Stationary-phase cells of both Pss and Pp were more susceptible to fatal UV damage than logarithmic-phase cells. This observation suggests that an active metabolism is involved in responses to protect against UV. Mutants of Pss and Pp, with insertions in rpoS, catA, and sodA and B, were all more severely affected by UV than the wild-types. These findings lead us to speculate that mechanisms to protect against oxidative stress are important in cell survival against UVA/B irradiation.