|
|
Authors: | J.L. Norelli, C.L. Bassett, D.A. Lalli, R.E. Farrell, Jr., A.M. Baldo, H.S. Aldwinckle |
Keywords: | apple, fire blight, Rosaceae, plant pathogenic bacteria, fruit tree diseases, Gala, suppression subtractive hybridization, expressed sequence tag, EST, gene regulation |
DOI: | 10.17660/ActaHortic.2008.793.26 |
Abstract:
Suppression subtractive cDNA hybridization (SSH) was used to identify genes that are differentially up- and down-regulated in apples (Malus ×domestica) in response to challenge with Erwinia amylovora (Ea). cDNA libraries were constructed from E. amylovora- and mock-challenged ‘Gale Gala’ apple leaf tissue at various time intervals after challenge treatment, ranging from 1 to 72 hours post inoculation (hpi) and utilized in SSH. A total of 432 non-redundant Malus ESTs isolated by SSH in response to E. amylovora challenge were characterized by bioinformatic analysis.
Many ESTs identified following Ea-challenge of apple were similar to genes previously reported to respond to bacterial challenge in Arabidopsis thaliana. The results indicate that there was a substantial early (1 and 2 hpi) transcriptional response in apple to fire blight disease involving both the down- and up-regulation of host genes.
Additionally, genes identified responding to fire blight challenge early (1 and 2 hpi) differed from those identified later (24, 48, 72 hpi) in the infection process.
For example, within the defense/stress functional category, ESTs representing several different PR proteins were first detected 48 hpi (up-regulated), whereas earlier defense/stress ESTs were primarily associated with oxidative and osmotic stress.
|
Download Adobe Acrobat Reader (free software to read PDF files) |
|