Szabó, Zoltan , Li, Nan , Winterhagen, Patrick , Qiu, Wenping , Kovacs, Laszlo G. .
Powdery mildew-induced changes in salicylic acid levels and related gene expression in grapevine.
Powdery mildews (PMs) cause economically important diseases on a broad range of plant species. On susceptible hosts, PM fungi are able to infect epidermal cells and extract nutrients from the plant without triggering cell death. Despite this intriguing interaction between host and pathogen, little is know about how PM fungi influence signal transduction processes in the plant. Our previous observations that a PM-resistant grapevine accumulates considerably higher levels of salicylic acid (SA) than a susceptible grapevine prompted us to analyze PM-induced changes in SA levels and in SA-related gene expression in the susceptible grapevine (Vitis vinifera)-PM (Erysiphe necator) pathosystem. We also examined if methyl salicylate (MeSA)-elicited SA accumulation and gene expression differed in healthy and PM-infected leaves. We found that total salicylate levels increased in response to PM infection and that the transcription of most genes involved in the SA signaling pathway responded in a similar manner in healthy and PM-infected leaves. We observed, however, that the expression of a gene encoding a salicylic acid carboxyl methyltransferase (SAMT) enzyme increased 40-fold in PM-infected leaves. This suggests that MeSA synthesis may play a role in grapevine’s response to PM infection. Based on these findings, we predict that the expression of many other genes in SA signaling pathways is altered by PM pathogenesis. We are currently exploring this possibility at the transcriptome level using microarrays.
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1 - Szent Istvan University University, Genetics and Plant Breeding
2 - Missouri State University, Agriculture
3 - Missouri State University, Agriculture, 9740 Red Spring Road, Mountain Grove, MO, 65711, USA
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM