AOBPreview originally published online on September 19, 2007
Annals of Botany 2008 101(2):261-265; doi:10.1093/aob/mcm032
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
A Role for IAA in the Infection of Arabidopsis thaliana by Orobanche aegyptiaca

Department of Plant and Environmental Sciences, Hebrew University of Jerusalem, Jerusalem 91904, Israel
* For correspondence. E-mail mayer{at}vms.huji.ac.il
Received: 1 November 2006 Returned for revision: 4 January 2007 Accepted: 18 January 2007 Published electronically: 19 September 2007
Background: Vascular continuity is established between a host plant and the root parasite broomrape. It is generally accepted that the direction of vascular continuity results from polar flow of auxin. Our hypothesis was that chemical disruptions of auxin transport and activity could influence the infection of the host by the parasite.
Methods: A sterile system for the routine infection of Arabidopsis thaliana seedlings in Nunc cell culture plates by germinated seeds of Orobanche aegyptiaca was developed. This method permitted a quantitative assay of the rate of host infection. The three-dimensional structure of the vascular contacts was followed in cleared tissue. IAA (indole acetic acid) or substances that influence its activity and transport were applied locally to the host root.
Results: The orientation of the xylem contacts showed that broomrape grafts itself upon the host by acting hormonally as a root rather than a shoot. Local applications of IAA, PCIB (p-chlorophenoxyisobutyric acid) or NPA (naphthylphthalamic acid) all resulted in drastic reductions of Orobanche infection
Conclusions: Broomrape manipulates the host by acting as a sink for auxin. Disruption of auxin action or auxin flow at the contact site could be a novel basis for controlling infection by Orobanche.
Key words: Orobanche aegyptiaca, Arabidopsis thaliana, p-chlorophenoxyisobutyric acid, hormonal flow, host infection, naphthylphthalamic acid, parasitic plants, polarity, vascular connections, xylem
Deceased.
![]()
CiteULike
Connotea
Del.icio.us What's this?
Related articles in Ann Bot:
- ContentSnapshots
Ann Bot 2008 101: NP.[Extract] [Full Text]
This article has been cited by other articles:
![]() |
I. Ridge and M. Jackson Daphne J. Osborne (1925 2006) Ann. Bot., January 1, 2008; 101(2): 199 - 201. [Full Text] [PDF] |
||||
