Skip to Main Content
 

Global Search Box

 
 
 
 

Files

File List


osu1306863052.pdf (7.49 MB)

ETD Abstract Container

Abstract Header

INVESTIGATIONS INTO MECHANISMS OF ASH RESISTANCE TO THE EMERALD ASH BORER

Whitehill, Justin G. A.
http://rave.ohiolink.edu/etdc/view?acc_num=osu1306863052

Abstract Details

2011, Doctor of Philosophy, Ohio State University, Plant Pathology.
The emerald ash borer (EAB; Agrilus planipennis Fairmaire) is an invasive phloem-feeding, wood-boring insect that was introduced to southeastern Michigan from Asia and first discovered in the U.S. in 2002. EAB larvae kill ash (Fraxinus spp.) trees by disrupting the flow of water and nutrients throughout the main stem of host plants. While all North American species of ash are susceptible to attack by EAB, an Asian species, Manchurian ash, is resistant. It is hypothesized that Manchurian ash resists EAB colonization by deploying targeted defenses that developed over time by virtue of its co-evolutionary history with the insect. These defenses can be broken down into constitutive and induced, physical and chemical defenses. We investigated constitutive and induced mechanisms of resistance in ash using proteomic and metabolomics approaches to study physiologically altered trees belonging to resistant and susceptible species from diverse phylogenetic backgrounds. We found significantly increased EAB attack rates below the girdle in susceptible ash species but not in resistant Manchurian ash, while exogenous treatment with a regulatory defense phytohormone, methyl jasmonate (MeJA) provided protection from attack by EAB at the same rate as an insecticide formulated against phloem feeding insects (Chapter 2). Application of MeJA to the outer bark of Manchurian and white ash also had significant effects on phloem phenolic profiles (Chapter 5). Furthemore, four proteins were constitutively expressed at significantly higher levels in the phloem tissues of Manchurian ash than in susceptible black, green, and white ashes and may therefore represent important components of constitutive resistance of Manchurian ash (Chapter 3). Comparisons of constitutive phloem phenolic profiles of six ash species revealed differences in secondary chemistry that were reflective of their phylogenetic relationships and may be associated with constitutive resistance (Chapter 4). Finally, proteomic and metabolomic characterization of oral secretions of 4th instar EAB larvae revealed a highly active molecular environment reflective of the dynamic interaction between ash and EAB (Chapter 6).
Pierluigi 'Enrico' Bonello, Ph.D. (Advisor)
Daniel Herms, Ph.D. (Committee Co-Chair)
Larry Phelan, Ph.D (Committee Member)
Brian McSpadden Gardener, Ph.D. (Committee Member)
Jennifer Koch, Ph.D. (Committee Member)
Guo-Liang Wang, Ph.D. (Committee Member)
250 p.
Plant Pathology
emerald ash borer; tree; Fraxinus; plant-insect interactions; proteomics; metabolomics; resistance; plant defense

Recommended Citations

Citations

  • Whitehill, J. G. A. (2011). INVESTIGATIONS INTO MECHANISMS OF ASH RESISTANCE TO THE EMERALD ASH BORER [Doctoral dissertation, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1306863052

    APA Style (7th edition)

  • Whitehill, Justin. INVESTIGATIONS INTO MECHANISMS OF ASH RESISTANCE TO THE EMERALD ASH BORER. 2011. Ohio State University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1306863052.

    MLA Style (8th edition)

  • Whitehill, Justin. "INVESTIGATIONS INTO MECHANISMS OF ASH RESISTANCE TO THE EMERALD ASH BORER." Doctoral dissertation, Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1306863052

    Chicago Manual of Style (17th edition)

osu1306863052
1,191
© 2011, all rights reserved.
This open access ETD is published by The Ohio State University and OhioLINK.