SBIR Phase I:Bioluminescent reporter phage for the rapid and specific detection of the causative agent of bacterial blight

This Small Business Innovation Research Phase I project will generate a "light-tagged" reporter phage that can confer a bioluminescent signal to the phytopathogen Pseudomonas syringae pv. alisalensis. P. syringae pv. alisalensis is the causative agent of bacterial blight, a contagious and damaging disease afflicting cruciferous vegetables. Since the severity of the disease renders the crop unmarketable, it is essential to be able to correctly identify the agent on asymptomatic and diseased plants, and from inoculum reservoirs. The Phase I goal is to develop a bioluminescent reporter phage for the detection of P. syringae pv. alisalensis. The objective is to generate a specific P. syringae pv. alisalensis light-tagged reporter phage and then perform feasibility studies to demonstrate that the light-tagged reporter can be used as a P. syringae pv. alisalensis detection system. The research is expected to generate a viable recombinant reporter phage that can rapidly, sensitively, and specifically confer a bioluminescent signal response, and hence detect P. syringae pv. alisalensis. The broader impact/commercial potential of this project is that the P. syringae pv. alisalensis diagnostic may help to reduce damage to commercially grown vegetable crops throughout the U.S. Symptoms first appear as small water-soaked flecks on the lower foliage. These flecks or lesions expand and become surrounded by bright yellow borders that eventually coalesce to form large necrotic areas. Bacterial blight infestations can result in crop damage to 60% of the commercial field. P. syringae pv. alisalensis has a broad host range afflicting monocots (California brome, oats), crucifers (cauliflower, broccoli, broccoli raab, brussels sprouts, cabbage, radish, arugula) and tomato. The value of Brassica oleracea vegetables alone (e.g. broccoli, cauliflower, cabbage and brussels sprouts) is estimated at $1.3 billion annually in the U.S. Consequently, the economic losses due to bacterial blight are potentially severe. However, to date, there are no commercially available or approved P. syringae pv. alisalensis detection methodologies. The long-term goal of this research is to develop a novel diagnostic kit for the detection of this agriculturally important phytopathogen. The research also may provide the foundation technology for the development of biosensors for other agriculturally important bacterial pathogens.