English
Time-Resolved Dual RNA-Seq Reveals Pathogenic Strategies of Bipolaris oryzae During Rice Infection
Yebin Nam1, Yoeguang Hue1, Byungheon Choi1, Jinyong Kim2, Ki-Tae Kim1,2*
1Department of Plant Medicine, Sunchon National University, Suncheon 57922, Republic of Korea
2Department of Agricultural Life Science, Sunchon National University, Suncheon 57922, Korea
*Email: kitaekim@scnu.ac.kr
Brown spot of rice, caused by the necrotrophic pathogen Bipolaris oryzae, is a major disease of rice, and its incidence and severity are increasing under the high-temperature and high-humidity conditions associated with climate change. However, the time-dependent transcriptomic changes in both the host and pathogen during infection remain insufficiently understood. In this study, dual RNA-seq analysis was performed to investigate transcriptomic dynamics during infection. Rice (Oryza sativa L. cv. Shindongjin) was inoculated with B. oryzae strain Bo-1_F1371, and samples were collected at 0, 12, 24, 36, and 48 hours post inoculation (hpi). Differentially expressed gene analysis comparing infected and non-infected samples revealed stage-specific transcriptional responses in the pathogen. At the early stage of infection (12 hpi), genes related to appressorium formation, host signal sensing, RNA polymerase complexes, and transcriptional regulation were upregulated. At the middle stage (24 hpi), genes involved in secondary metabolite biosynthesis and DNA replication were highly expressed. At the progression stage (36 hpi), genes associated with oxidative stress response and redox homeostasis were upregulated. At the late stage (48 hpi), genes related to polarized hyphal growth through actin binding, as well as protein turnover and nutrient acquisition via the proteasome complex and endosome–vacuole transport, were induced. These results indicate that B. oryzae dynamically modulates its transcriptional programs during infection. This study provides insights into rice–pathogen interactions and supports the development of resistant rice cultivars. [This work was supported by the Rural Development Administration of Korea (RS-2024-00400211)]
