ABSTRACT
Characterization of the wild rice Oryza rufipogon transcriptomes associated with susceptibility to Burkholderia glumae

Mohamad Iqbal Hakim Mohd Azhan1, Dzarifah Zulperi2, Shairul Izan Ramlee3, Mohd Razi Ismail3, Siti Nor Akmar Abdullah1, and Muhammad Asyraf Md Hatta1*
 
Bacterial panicle blight (BPB), caused by Burkholderia glumae (Bg) is an emerging rice disease. Characterizing the host’s transcriptome at various time points following pathogen infection can provide valuable insights into the defence mechanisms during a compatible interaction. Thus, this study aimed to investigate the interaction between common wild rice, Oryza rufipogon Griff., and Bg at the transcriptome level upon infection of a susceptible accession, IRGC 86685. Following Bg infection on the stems of young plants, the disease responses were observed at 24, 48, 72, and 96 h post inoculation (hpi). After 72 h, visible browning started to emerge around the injection sites. The transcriptome analysis revealed 1014 (468 up-regulated and 546 down-regulated), 830 (665 up-regulated and 165 down-regulated), 2207 (1174 up-regulated and 1033 down-regulated), and 1993 (863 up-regulated and 1130 down-regulated) differentially expressed transcripts (DETs) at different time points. The highest level of differential expression observed at 72 hpi was consistent with the increased level of BPB symptoms at this time point. The gene ontology (GO) term enrichment analysis shows that most of the up-regulated DETs correspond to membrane, transporter activity, and response to stress across all time points in the cellular component, molecular function, and biological process, respectively, suggesting their involvement in IRGC 86685’s response to Bg. These findings shed light on the molecular mechanisms underlying BPB susceptibility in wild rice during Bg infection, aiming to improve rice resistance to this pathogen.
Keywords: Bacterial panicle blight, Burkholderia glumae, Oryza rufipogon, RNA-seq analysis, wild rice.
1Universiti Putra Malaysia, Faculty of Agriculture, Department of Agriculture Technology, Selangor, Malaysia.
2Universiti Putra Malaysia, Faculty of Agriculture, Department of Plant Protection, Selangor, Malaysia.
3Universiti Putra Malaysia, Faculty of Agriculture, Department of Crop Science, Selangor, Malaysia.
*Corresponding author (m.asyraf@upm.edu.my)