You are not currently logged in.
Access your personal account or get JSTOR access through your library or other institution:
If You Use a Screen ReaderThis content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Response to Xanthomonas campestris pv. vesicatoria in Tomato Involves Regulation of Ethylene Receptor Gene Expression
Joseph A. Ciardi, Denise M. Tieman, Steven T. Lund, Jeffrey B. Jones, Robert E. Stall and Harry J. Klee
Vol. 123, No. 1 (May, 2000), pp. 81-92
Published by: American Society of Plant Biologists (ASPB)
Stable URL: http://www.jstor.org/stable/4279239
Page Count: 12
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Preview not available
Although ethylene regulates a wide range of defense-related genes, its role in plant defense varies greatly among different plant-microbe interactions. We compared ethylene's role in plant response to virulent and avirulent strains of Xanthomonas campestris pv. vesicatoria in tomato (Lycopersicon esculentum Mill.). The ethylene-insensitive Never ripe (Nr) mutant displays increased tolerance to the virulent strain, while maintaining resistance to the avirulent strain. Expression of the ethylene receptor genes NR and LeETR4 was induced by infection with both virulent and avirulent strains; however, the induction of LeETR4 expression by the avirulent strain was blocked in the Nr mutant. To determine whether ethylene receptor levels affect symptom development, transgenic plants overexpressing a wild-type NR cDNA were infected with virulent X. campestris pv. vesicatoria. Like the Nr mutant, the NR overexpressors displayed greatly reduced necrosis in response to this pathogen. NR overexpression also reduced ethylene sensitivity in seedlings and mature plants, indicating that, like LeETR4, this receptor is a negative regulator of ethylene response. Therefore, pathogen-induced increases in ethylene receptors may limit the spread of necrosis by reducing ethylene sensitivity.
Plant Physiology © 2000 American Society of Plant Biologists (ASPB)