Skip to main content
ARS Home » Southeast Area » Stuttgart, Arkansas » Dale Bumpers National Rice Research Center » Research » Publications at this Location » Publication #343358
Title: Characterization and in plant detection of bacteria that cause bacterial panicle blight disease of rice

Author
item MULAW, TEMESGEN - University Of Arkansas
item WAMISHE, YESHI - University Of Arkansas
item Jia, Yulin

Submitted to: American Journal of Plant Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/23/2018
Publication Date: 3/14/2018
Citation: Mulaw, T., Wamishe, Y., Jia, Y. 2018. Characterization and in plant detection of bacteria that cause bacterial panicle blight disease of rice. American Journal of Plant Sciences. https://doi.org:10.4236/ajps.2018.94053.
DOI: https://doi.org/10.4236/ajps.2018.94053

Interpretive Summary: Bacterial panicle blight (BPB) disease caused by a bacterial pathogen, Burkholderia glumae, appears to occur more frequently and has caused increased crop losses in recent years in the USA. The present study was designed to determine the causal agent of BPB, virulence, and distribution within the plant using 178 rice panicles with BPB symptoms collected from nine counties in Arkansas in 2015. These samples were analyzed with artificial detection medium (CCNT) and Kings B media, molecular detection with a gene specific marker, and reactions on tobacco leaves. A total of 73 samples out of 178 yielded a bacterial colony with similar morphology on CCNT and Kings B media suggesting they were BPB. However, only 45 of the 73 were moleculary verified to be B. glumae while the others were undetermined suggesting that B. glumae is one of the causal agents of BPB. Based on lesion sizes on tobacco leaves, highly virulent, moderately virulent, and weakly virulent isolates were distinguished among the 45 B. glumae; this suggests that different levels of genetic resistance exist to this pathogen. With CCNT media and PCR analysis, we identified bacteria in the seed, stem, and sheath, but not in the leaf or root, suggesting that the pathogen is distributed among the stem, sheath, and seed. Together we demonstrated the usefulness of artificial culture media, tobacco reactions, and molecular testing for characterization of BPB, and distribution of bacteria in plants. These findings are beneficial for developing methods to manage BPB disease.

Technical Abstract: Burkholderia glumae (BPB) presumably induces a grain rot symptom of rice that is threatening to production in most southern rice producing states of the USA. The present study was to determine the causal agent of BPB, virulence based on hypersensitive reactions on tobacco leaves, and distribution of the pathogen within the plant. A total of 178 rice panicles with symptoms of BPB collected from nine Arkansas counties were used for pathogen identification. These samples were analyzed with an artificial detection (CCNT) and King B media, polymerase chain reaction (PCR) with bacterial 16S rDNA markers, and hypersensitive reactions on tobacco leaves. A total of 73 samples out of 178 produced a yellow bacterial colony with similar morphology on CCNT and King B medium suggesting they were bacterial panicle diseases. However, with PCR reactions, it was determined that 45 of 73 were due to B. glumae, and the causal agent for the remaining samples was undetermined, indicating that B. glumae is not the only causal agent for BPB. Within the 45 samples, 31 highly, 6 moderately, and 5 weakly virulent isolates were grouped based on lesion size of the hypersensitive reactions of tobacco leaves. Pathogenicity variability among the 45 B. glumae isolates detected suggests that different degrees of host resistance exist. To determine the existence of bacteria in different plant tissues, ten naturally infected plant parts were examined with CCNT and Kings B media and PCR analysis. B. glumae was again isolated from seeds, stems and sheaths from light yellow pigmented growth on CCNT media. In contrast, roots and leaves did not show any visible yellow pigment on CCNT media. Consistent PCR products were produced from the stem, sheath, and seed, but not from the root and leaves. These findings suggest that B. glumae is distributed in the stem, sheath, and seed, and not in the leaf and root. Together, these results demonstrate the usefulness of artificial culture media, tobacco reactions, and DNA tests for characterization of BPB, and distribution of bacteria in plants. These findings will help to understand the mechanism of bacteria translocation in plants, and ultimately to identify host resistance genes to manage BPB disease.