Susceptibility to the Sugar Beet Cyst Nematode Is Modulated by Ethylene Signal Transduction in Arabidopsis thaliana

Thumbnail Image
Date
2001-10-01
Authors
Wubben, Martin
Su, Hong
Rodermel, Steven
Baum, Thomas
Major Professor
Advisor
Committee Member
Journal Title
Journal ISSN
Volume Title
Publisher
Authors
Person
Research Projects
Organizational Units
Organizational Unit
Journal Issue
Is Version Of
Versions
Series
Department
Plant Pathology and MicrobiologyGeneticsBotany
Abstract

Previously, we identified Arabidopsis thaliana mutant rhd1-4 as hypersusceptible to the sugar beet cyst nematode Heterodera schachtii. We assessed rhd1-4 as well as two other rhd1 alleles and found that each exhibited, in addition to H. schachtii hypersusceptibility, decreased root length, increased root hair length and density, and deformation of the root epidermal cells compared with wild-type A. thaliana ecotype Columbia (Col-0). Treatment of rhd1-4 and Col-0 with the ethylene inhibitors 2-aminoeth-oxyvinylglycine and silver nitrate and the ethylene precursor 1-aminocyclopropane-1-carboxylic acid suggests that the rhd1-4 hypersusceptibility and root morphology phenotypes are the result of an increased ethylene response. Assessment of known ethylene mutants further support the finding that ethylene plays a role in mediating A. thaliana susceptibility to H. schachtiibecause mutants that overproduce ethylene (eto1-1, eto2, and eto3) are hypersusceptible to H. schachtii and mutants that are ethylene-insensitive (etr1-1, ein2-1, ein3-1, eir1-1, and axr2) are less susceptible to H. schachtii. Because the ethylene mutants tested show altered susceptibility and altered root hair density and length, a discrimination between the effects of altered ethylene signal transduction and root hair density on susceptibility was accomplished by analyzing the ttg and gl2 mutants, which produce ectopic root hairs that result in greatly increased root hair densities while maintaining normal ethylene signal transduction. The observed normal susceptibilities to H. schachtii of ttg and gl2 indicate that increased root hair density, per se, does not cause hypersusceptibility. Furthermore, the results of nematode attraction assays suggest that the hypersusceptibility of rhd1-4and the ethylene-overproducing mutant eto3 may be the result of increased attraction of H. schachtii-infective juveniles to root exudates of these plants. Our findings indicate that rhd1 is altered in its ethylene response and that ethylene signal transduction positively influences plant susceptibility to cyst nematodes.

Comments

This article is published as Wubben, Martin JE, Hong Su, Steven R. Rodermel, and Thomas J. Baum. "Susceptibility to the sugar beet cyst nematode is modulated by ethylene signal transduction in Arabidopsis thaliana." Molecular Plant-Microbe Interactions 14, no. 10 (2001): 1206-1212, doi: 10.1094/MPMI.2001.14.10.1206. Posted with permission.

Description
Keywords
Citation
DOI
Copyright
Mon Jan 01 00:00:00 UTC 2001
Collections