Diversity of Bacteriophages Infecting Xanthomonas oryzae pv. oryzae in Paddy Fields and Its Potential to Control Bacterial Leaf Blight of Rice

Abstract

Bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae (Xoo) is a very serious disease in rice-growing regions of the world. In spite of their economic importance, there are no effective ways of protecting rice plants from this disease. Bacteriophages infecting Xoo affect the population dynamics of the pathogen and consequently the occurrence of the disease. In this study, we investigated the diversity, host range, and infectivity of Xoo phages, and their use as a bicontrol agent on BLB was tested. Among the 34 phages that were isolated from floodwater in paddy fields, 29 belonged to the Myoviridae family, which suggests that the dominant phage in the ecosystem was Myoviridae. The isolated phages were classified into two groups based on plaque size produced on the lawn of Xoo. In general, there was a negative relationship between plaque size and host range, and interestingly the phages having a narrow host range had low efficiency of infectivity. The deduced protein sequence analysis of htf genes indicated that the gene was not a determinant of host specificity. Although the difference in host range and infectivity depending on morphotype needs to be addressed, the results revealed deeper understanding of the interaction between the phages and Xoo strains in floodwater and damp soil environments. The phage mixtures reduced the occurrence of BLB when they were treated with skim milk. The results indicate that the Xoo phages could be used as an alternative control method to increase the control efficacy and reduce the use of agrochemicals.

Methylome Analysis of Two Xanthomonas spp. Using Single-Molecule Real-Time Sequencing

“…In addition, DNA methylation is one of the known antiviral mechanisms of bacteria (Labrie et al, 2010). Within the same bacterial species, different strains show distinct resistant patterns against infection of diverse bacteriophages (Chae et al, 2014). Host ranges of bacteriophages are most likely determined by specific DNA methyltransferases in bacteria.…”

Controlling the Microbiome: Microhabitat Adjustments for Successful Biocontrol Strategies in Soil and Human Gut

“…and Dickeya sp. (Evans et al, 1979 ; Sharp et al, 1986 ; Lynch et al, 2012 ; Chae et al, 2014 ; Santamaría et al, 2014 ; Czajkowski et al, 2015 ). For this approach, elimination of pathogens and reduction of soil bacterial species that directly compete with the biocontrol agents (i.e., those sharing similar metabolic capacities) are desirable.…”

Novel groups and unique distribution of phage phoH genes in paddy waters in northeast China

“…observed that the abundance of virus-like particles (VLPs) in paddy floodwaters during the rice cultivation period ranged from 5.6 × 10 6 to 1.2 × 10 9  VLPs·mL −1 with a mean of 1.5 × 10 8  VLPs·mL −1 , which was greater than the number of viruses in oceans and estuaries1617. Chae et al 18. isolated 34 phages infecting Xanthomonas oryzae pv.…”