Molecular Plant-Microbe Interactions (1998) 11, 530-536

J.H. Westwood, X.S. Yu, C.L. Foy and C.L. Cramer (1998)
Expression of a defense-related 3-hydroxy-3-methylglutaryl COA reductase gene in response to parasitization by Orobanche spp.
Molecular Plant-Microbe Interactions 11 (6), 530-536
Abstract: Orobanche spp. are angiosperms that live parasitically on the roots of other plants, and are capable of significantly reducing the yield and quality of their crop hosts. We have demonstrated that parasitization by Orobanche induces expression of hmg2, a defense-related isogene of 3-hydroxy-3-methylglutaryl CoA reductase (HMGR) in tobacco. Transgenic tobacco plants expressing a construct containing 2.3 kb of the tomato hmg2 gene promoter fused to the beta-glucuronidase (GUS) reporter gene were parasitized by O. aegyptiaca. Expression of the hmg2:GUS construct was detected within 1 day following penetration of the host root by the O. aegyptiaca radicle and was localized to the region immediately around the site of parasite invasion. This expression continued and intensified over the course of O. aegyptiaca development. In addition, the hmg2:GUS expression was induced by secondary parasitization, where secondary roots of O. aegyptiaca contacted the host root at a distance from the primary attachment site. This GUS expression was specific to plants containing the hmg2:GUS construct, and was not observed in control plants transformed with a construct of the cauliflower mosaic virus 35S promoter fused to the GUS gene. These results indicate that Orobanche parasitization initiates rapid and sustained induction of a defense-related gene in the host root.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): James H. Westwood

Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution
resistance/tolerance/defence of host

---

Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Phelipanche aegyptiaca (weed)	Tobacco (Nicotiana tabacum)