Degree Type


Date of Award


Degree Name

Doctor of Philosophy


Genetics, Development and Cell Biology



First Advisor

Steve A. Whitham

Second Advisor

Jo Anne Powell-Coffman


Abstract: FERONIA (FER), a plasmamembrane-localized receptor kinase plays vital roles in plant growth development and stress responses. In the past decade, ligands, co-receptors, and many signaling components have been identified to shine light on the regulatory mechanisms. However, a comprehensive signaling network underlying FER-mediated diverse processes is still lacking.

To this end, and also to facilitate the discovery of novel FER-mediated pathways, we carried out transcriptomic, proteomic and phosphoproteomic analyses. From the transcriptome analysis, we discovered that FER is a major negative regulator of plant hormone Jasmonic acid (JA) signaling. Further genetics, biochemistry and cell biology experiments demonstrate that FER phosphorylates and destabilizes MYC2 to inhibit JA signaling and MYC2-mediated host plant susceptibility, which establishes FER as a positive regulator in bacterial pathogen defense. RALF23, a rapid alkalization factor and a peptide ligand for FER, functions through FER to negatively contribute to bacterial defense.

The proteome analysis validates previous findings such as negative regulation of FER on JA, and supports a role of FER in maintaining nutrient and energy homeostasis. The phosphoproteomics data analysis identified a group of transcription factors that potentially carry out diverse functions. The omics data has also revealed novel FER-mediated processes.

The dissertation research establishes RALF23-FERONIA-MYC2, a ligand-receptor-transcription factor signaling module, as one of the underlying mechanisms for FER-mediated bacterial defense. Further studies on the newly identified candidate substrate transcription factors and novel pathways will broaden our understanding on how FERONIA, a plasmamembrane-localized receptor kinase, regulates plant growth development and stresses responses.

Copyright Owner

Hongqing Guo



File Format


File Size

188 pages

Available for download on Sunday, April 18, 2021

Included in

Genetics Commons