February
2007
, Volume
20
, Number
2
Pages
107
-
119
Authors
Mitra Mazarei,1
Axel A. Elling,1,2
Tom R. Maier,1
David P. Puthoff,1 and
Thomas J. Baum1,2
Affiliations
1Department of Plant Pathology and 2Interdepartmental Genetics Program, Iowa State University, Ames 50011, U.S.A.
Go to article:
RelatedArticle
Accepted 28 August 2006.
Abstract
Ethylene-responsive element-binding proteins (EREBPs) are plant-specific transcription factors, many of which have been linked to plant defense responses. Conserved EREBP domains bind to the GCC box, a promoter element found in pathogenesis-related (PR) genes. We previously identified an EREBP gene from soybean (GmEREBP1) whose transcript abundance decreased in soybean cyst-nematode-infected roots of a susceptible cultivar, whereas it increased in abundance in infected roots of a resistant cultivar. Here, we report further characterization of this gene. Transient expression analyses showed that GmEREBP1 is localized to the plant nucleus and functions as a transcriptional activator in soybean leaves. Transgenic soybean plants expressing GmEREBP1 activated the expression of the ethylene (ET)-responsive gene PR2 and the ET- and jasmonic acid (JA)-responsive gene PR3, and the salicylic acid (SA)-responsive gene PR1 but not the SA-responsive PR5. Similarly, transgenic Arabidopsis plants expressing GmEREBP1 showed elevated mRNA abundance of the ET-regulated gene PR3 and the ET- and JA-regulated defense-related gene PDF1.2 but not the ET-regulated GST2, and the SA-regulated gene PR1 but not the SA-regulated PR2 and PR5. Transgenic soybean and Arabidopsis plants inoculated with cyst nematodes did not display a significantly altered susceptibility to nematode infection. These results collectively show that GmEREBP1 functions as a transacting inducer of defense gene expression in both soybean and Arabidopsis and mediates the expression of both ET- and JA- and SA-regulated defense-related genes in these plant species.
JnArticleKeywords
Additional keywords:cis elements,
ethylene-insensitive soybean mutant etr1-1,
GFP,
GUS,
protoplasts,
quantitative real-time reverse-transcription PCR.
Page Content
ArticleCopyright
© 2007 The American Phytopathological Society