Gram-negative Burkholderia bacteria are known for causing diseases in humans, animals, and plants, and high intrinsic resistance to antibiotics. Phage therapy is a promising alternative to control multidrug-resistant bacterial pathogens. Here, we present an overview of Burkholderia phage characteristics, host specificity, genomic classification, and therapeutic potentials across medical, veterinary, and agricultural systems. We evaluate the efficacy and limitations of current phage candidates, the biological and environmental barriers of phage applications, and the phage cocktail strategy. We highlight the innovations on the development of targeted phage delivery systems and the transition from the exploration of clinical phage therapy to plant disease management, advocating integrated disease control strategies.

Xanthomonas oryzae pv. oryzae (Xoo) is the causative agent of rice bacterial blight (RBB), resulting in substantial harvest losses and posing a challenge to maintaining a stable global supply. In this study, Xoo strains isolated from Shaoxing, Quzhou, and Taizhou, where RBB occurred most frequently in Zhejiang Province in 2019, were selected as the subjects of research. Three isolated pathogenic bacteria of ZXooS (from Shaoxing), ZXooQ (from Quzhou), and ZXooT (from Taizhou) were all identified as novel Xoo strains. These novel strains demonstrate greater virulence compared to Zhe173, the previous epidemic Xoo strain from Zhejiang Province. Subsequent genomic sequencing and analysis revealed that there existed significant differences in the genome sequence, especially in effector genes corresponding to some known rice resistance (R) genes between the novel strains and Zhe173. The sequence alignment of avirulent genes (effector genes) indicated that nucleic and amino acid sequences of AvrXa5, AvrXa7, AvrXa10, and AvrXa23 in the novel strains varied prominently from those in Zhe173. Interestingly, it seemed that only the genome of ZXooQ might contain the AvrXa3 gene. In addition, the phylogenetic analysis of 61 Xoo strains revealed that the novel strains were situated in a distinct evolutionary clade separate from Zhe173. These results here suggest that the emergence of novel Xoo strains may lead to resistance loss of some R genes used in commercial rice varieties, potentially serving as one of the factors leading to RBB resurgence in Zhejiang Province, China.

Xanthomonas oryzae pv. oryzae (Xoo) is a significant bacterial pathogen responsible for outbreaks of bacterial leaf blight in rice, posing a major threat to rice cultivation worldwide. Effective management of this pathogen is crucial for ensuring rice yield and food security. In this study, we identified and characterized a novel Xoo phage, ZP3, isolated from diseased rice leaves in Zhejiang, China, which may offer new insights into biocontrol strategies against Xoo and contribute to the development of innovative approaches to combat bacterial leaf blight. Transmission electron microscopy indicated that ZP3 had a short, non-contractile tail. Genome sequencing and bioinformatic analysis showed that ZP3 had a double-stranded DNA genome with a length of 44,713 bp, a G + C content of 52.2%, and 59 predicted genes, which was similar to other OP1-type Xoo phages belonging to the genus Xipdecavirus. ZP3’s endolysin LysZP was further studied for its bacteriolytic action, and the N-terminal transmembrane domain of LysZP is suggested to be a signal–arrest–release sequence that mediates the translocation of LysZP to the periplasm. Our study contributes to the understanding of phage–Xoo interactions and suggests that phage ZP3 and its endolysin LysZP could be developed into biocontrol agents against this phytopathogen.

Achieving high yield while maintaining disease resistance is a crucial goal in rice breeding programs. In this research, two cultivated rice varieties, Jia58 and Runxiang3, were selected as parental lines. A new variety, designated as the new variety RXN2, was generated and identified through a breeding process that involved hybridization of the parental lines followed by irradiation-induced mutagenesis of the offspring. Compared with its parental lines, RXN2 shows increased plant height, higher yield, and stronger resistance to bacterial blight. Comprehensive transcriptomic and metabolic analyses indicate that pathways associated with growth, such as gibberellin and auxin signaling, are upregulated in RXN2. Meanwhile, defense-related pathways, especially those involving jasmonic acid and peroxidase metabolism, are significantly enhanced. These results provide new insights into the trade-offs between growth and defense and elucidate the genetic and metabolic underpinnings of the simultaneous improvement in grain yield and disease resistance in rice.