Degree

Doctor of Philosophy (PhD)

Department

Plant Pathology and Crop Physiology

Document Type

Dissertation

Abstract

Bacterial panicle blight (BPB), caused primarily by Burkholderia glumae, is an emerging disease in rice due to its increasing prevalence and severity influenced by warming. The intricate rice-B. glumae interaction underscores the necessity for a comprehensive strategy involving diverse genetic background and high-resolution genomic analyses. Leveraging genetic resources such as parental and mutant donors, alongside biparental populations, facilitated this study, albeit within a limited genetic pool. Utilizing an integrative omics approach, which includes genomics and transcriptomics, has been crucial in unraveling the genetic architecture and underlying mechanisms of BPB resistance in rice. While pathogen recognition is crucial in this system, it was found in this study that efficient modulation of defense/ stress response through complex interplays and regulation of alternative splicing of genes are also pivotal factors for this disease. In addition, a QTL linked to BPB resistance (qBPB3.2) was identified on chromosome 3, adjacent to a previously identified qBPB3.1 from the same donor, Jupiter. This region, enriched with defense-stress regulatory genes, was known to be a broad-spectrum resistance hotspot. Furthermore, through gamma radiation, the generation of a resistant mutant line, LM-1 from a susceptible variety Lemont, provided another dimension of valuable insights related to BPB resistance. Variants in this mutant influencing the BPB resistance phenotype, which were detected through comparative genome analysis utilizing both short and long reads sequencing, were located within loci associated with regulatory pathways of defense-stress response. Henceforth, by elucidating the genetic intricacies and regulatory networks governing BPB resistance mechanism, insights gained from this study can inform targeted breeding efforts and can also provide avenues for engineering rice with enhanced resilience to diverse biotic and abiotic stresses.

Date

6-27-2024

Committee Chair

Ham, Jong

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