Lipoxygenase (LOX)-derived oxylipins are known to play critical roles in defense
against herbivores and pathogens. The objective of this study was to determine
the biochemical, molecular and physiological roles of a specific maize
lipoxygenase gene, ZmLOX10, with special emphasis on LOX10-derived oxylipins
in plant-insect and plant-pathogen interactions. To achieve this goal, independent
mutant alleles were generated and genetically advanced to create near-isogenic
mutant and wild-type lines suitable for functional analysis. Here we provide
genetic evidence that LOX10 is the sole LOX isoform in maize required for the
biosynthesis of green leafy volatiles (GLV) in leaves and show that LOX10-
mediated GLVs play a significant role in direct and indirect defense responses to
insects through their regulation of jasmonic acid and volatile organic compound
production. Contrary to the defensive role of LOX10 in plant-insect interactions,
tests for susceptibility to fungal pathogens suggest that LOX10-mediated GLVs
may contribute to the development of disease symptoms to the economically important maize pathogens, Aspergillus flavus and Colletotrichum graminicola.
Specifically, LOX10-derived GLVs may facilitate aflatoxin accumulation in
response to A. flavus infection and may play a positive role in anthracnose leaf
blight and stalk rot caused by C. graminicola. Collectively, our results suggest that
metabolites derived from GLV-regulated pathways have a significant impact on
molecular plant-herbivore and plant-pathogen interactions.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-2009-12-7459 |
| Date | 2009 December 1900 |
| Creators | Christensen, Shawn A. |
| Contributors | Kolomiets, Michael |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Dissertation, text |
| Format | application/pdf |
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