Fusarium head blight (FHB) is an important disease of small grain cereals including wheat that affects grain quality and yield. The fungus Fusarium graminearum (Fg) is the major agent of this disease. Lack of natural resistance has limited ability to control wheat losses to this disease. Developing new approaches is critical for increasing host plant resistance to this fungus. This work has identified four processes that can be targeted for enhancing host plant resistance to FHB. The first involves targeting the pattern-triggered immunity mechanism to promote host plant resistance. Two other approaches involved reducing activity of susceptibility factors in the host to enhance plant resistance. The susceptibility factors targeted include accumulation of the phytohormone jasmonic acid and the 9-lipoxygenase pathway that oxidizes fatty acids. Besides suppressing host defenses against Fg, jasmonic acid also directly acts on the fungus to promote fungal growth. 9- lipoxygenases similarly suppress host defenses to promote fungal pathogenicity. Another approach that was developed involved having the plant express double stranded RNA to target fungal virulence genes for silencing. This host-induced gene silencing approach was employed to target two fungal virulence genes, the lipase encoding FGL1 and salicylate hydroxylase encoding FgNahG, which the fungus secretes into the host to promote turnover of the plant defense signaling metabolite salicylic acid. FGL1 in contrast acts on host lipids to release fatty acids, which suppress the deposition of callose that provides a physical barrier to limit fungal spread.
| Identifer | oai:union.ndltd.org:unt.edu/info:ark/67531/metadc1703417 |
| Date | 05 1900 |
| Creators | Alam, Syeda Tamanna |
| Contributors | Shah, Jyoti, Alonso, Ana P, Longo, Antonella, McGarry, Roisin, Shulaev, Vladimir |
| Publisher | University of North Texas |
| Source Sets | University of North Texas |
| Language | English |
| Detected Language | English |
| Type | Thesis or Dissertation |
| Format | xviii, 199 pages, Text |
| Rights | Public, Alam, Syeda Tamanna, Copyright, Copyright is held by the author, unless otherwise noted. All rights Reserved. |
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