PhD Oral Defense: Plant Cellular Signaling in Response to Wounding or Caterpillar Herbivory
PhD Oral Defense of Jamuna Risal Paudel, Department of Plant Science
Plants have complex signaling networks in response to wounding or caterpillar herbivory. The phytohormone jasmonic acid (JA) mediates the principal plant defense response pathway against caterpillar herbivory. However, some larval species manipulate host plant responses leading to the attenuation of this induced resistance (IR). Although the exact mechanism of the insect subversion of JA-mediated IR is not clearly understood, effectors in the labial salivary secretions of generalist Noctuid caterpillars, such as Spodoptera exigua, are known to activate the salicylic acid (SA)-mediated pathway that antagonize JA responses. Since the caterpillar labial saliva contains significant levels of oxido-reductive enzymes, such as glucose oxidase, it can manipulate cellular redox balance in plant tissues. Similarly, these effectors may activate the ethylene (ET) pathway leading to the modulation of JA pathway.