Main content

The effectiveness of induced plant disease resistance: genotypic variation and quantification by chlorophyll fluorescence

Show full item record

Title: The effectiveness of induced plant disease resistance: genotypic variation and quantification by chlorophyll fluorescence
Author: Tung, Jonathan
Department: Department of Environmental Biology
Program: Environmental Biology
Advisor: Goodwin, PaulHsiang, Tom
Abstract: Cultivars of Agrostis stolonifera showed weak and strong responsiveness to the systemic acquired resistance (SAR) activator, benzothiadiazole (BTH), or the induced systemic resistance (ISR) activator, 2R, 3R-butanediol (BD). Next Generation RNA sequencing was used to identify 2163 putative transcripts with increased expression in BTH versus water-treated A. stolonifera. Among three BTH-induced genes, AsASP-2 and AsHIR-1 were induced faster, while AsLOX-1 had stronger transient induction, in one out of two strongly BTH-responsive cultivars. Three ISR-responsive genes, AsGNS-5, AsOPR-4 and AsAOS-1, showed no greater induction or priming in the strongly versus weakly BD-responsive cultivars. Cultivars of A. stolonifera vary significantly in their response to defense activators, however this is not consistently related to defense gene expression. To quantify disease severity, chlorophyll fluorescence imaging of the maximum quantum efficiency of photosystem II (Fv/Fm) was tested on Nicotiana benthamiana infected with Colletotrichum orbiculare. Leaf areas of healthy, non-necrotic affected and necrotic tissue could be individually quantified, which demonstrated that BD delayed symptom development by approx. 24-hour and reduced non-necrotic affected tissue compared to controls. Chlorophyll fluorescence imaging can quantify and reveal novel features about induced disease resistance.
URI: http://hdl.handle.net/10214/3025
Date: 2011-09


Files in this item

Files Size Format View Description
tung_combined_thesis_ver15.pdf 2.187Mb PDF View/Open revised full thesis pdf

This item appears in the following Collection(s)

Show full item record