Characterization of a σ54-Dependent Response Regulator, tepR, in the Rice-Pathogenic Bacterium Burkholderia Glumae and Development of Biocontrol Strategies for Bacterial Panicle Blight of Rice

Bacterial panicle blight, caused by Burkholderia glumae, is a major bacterial disease of rice in Louisiana. This bacterium contains several virulence factors required for disease development such as toxoflavin, lipase and flagella. In a genome-wide search for regulatory factors related to the virulence of B. glumae, tepR was identified as a negative regulator for toxoflavin production and found to encode a sigma 54-dependent response regulator. TepR is homologous to LuxO, a quorum-sensing signaling component of Vibrio spp. A markerless tepR deletion mutant of B. glumae 336gr-1, LSUPB401, produced more toxoflavin and showed higher lipase and protease activities compared to the wild type, 336gr-1. The phenotype of mutant LSUPB401 was complemented by a functional tepR clone, confirming that tepR is a novel negative regulator for toxoflavin production in B. glumae. In addition, LSUPB401 was more aggressive than the wild type in causing symptoms on rice panicles and onion bulb scales. However, LSUPB401 lost flagellar motility and hypersensitive reaction, suggesting positive roles of tepR in those phenotypes. These findings suggest that TepR promotes the cellular functions for initial host colonization. Ten bacterial strains showing antagonistic activities against B. glumae in an in vitro assay were detected from several thousand bacterial isolates obtained from the root region of rice grown at the Rice Research Station, Crowley, Louisiana. Those bacteria were identified as Bacillus, Paenibacillus and Pseudomonas based on the 16S rDNA sequences. Some isolates suppressed bacterial panicle blight significantly in both greenhouse and field conditions, therefore, are potential candidates for further biocontrol studies

Labor-Intensive Multiple Cropping Systems and the H-2A Program: Evidence from the Crawfish Industry

Labor-intensive production operations, such as crawfish, depend on the H-2A program to secure labor. The 10-month limit on the H-2A guest-worker visa could affect the efficiency of these operations as employers will need to reapply to hire H-2A workers

Meat Goat Production in the United States: Adoption of Technologies, Management Practices, and Production Systems

In the United States, meat goat production has increased as the demand for goat meat has expanded due to immigration from Central and South America, Africa, Asia, and the Middle- East. Mail survey data were collected from US meat goat farmers during the summer of 2012, to examine the current status of US meat goat farms. Results obtained from the survey provide a snapshot into meat goat farmers’ adoption of technology, management practices, and production systems in the United States