Year of Publication
Doctor of Philosophy (PhD)
Agriculture, Food and Environment
Dr. Pradeep Kachroo
Systemic acquired resistance (SAR) is a form of inducible defense response triggered upon localized infection that confers broad-spectrum disease resistance against secondary infections. Several factors are known to regulate SAR and these include phenolic phytohormone salicylic acid (SA), phosphorylated sugar glycerol-3-phosphate (G3P), and dicarboxylic acid azelaic acid (AzA). This study evaluated a role for free radicals nitric oxide (NO) and reactive oxygen species (ROS) in SAR. Normal accumulation of both NO and ROS was required for normal SAR and mutations preventing NO/ROS accumulation and/or biosynthesis compromised SAR. A role for NO and ROS was further established using pharmacological approaches. Notably, both NO and ROS conferred SAR in a concentration dependent manner. This was further established using genetic mutants that accumulated high levels of NO. NO/ROS acted upstream of G3P and in parallel to SA. Collectively, these results suggest that NO and ROS are essential components of the SAR pathway.
Digital Object Identifier (DOI)
El-Shetehy, Mohamed H., "Molecular and Biochemical Signaling Underlying Arabidopsis-Bacterial/Virus/Fungal Interactions" (2016). Theses and Dissertations--Plant Pathology. 19.