Plant Biol (Stuttg) 2004; 6(2): 105-108
DOI: 10.1055/s-2004-817803
Rapid Communication

Georg Thieme Verlag Stuttgart · New York

Gene Expression Analysis in Cucumber Leaves Primed by Root Colonization with Pseudomonas chlororaphis O6 upon Challenge-Inoculation with Corynespora cassiicola

M. S. Kim1 , Y. C. Kim1 , B. H. Cho1
  • 1Agricultural Plant Stress Research Center and Institute of Agriculture, Science and Technology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju, South Korea
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Publication History

Publication Date:
26 March 2004 (online)

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Abstract

Root colonization by Pseudomonas chlororaphis O6, a non-pathogenic rhizobacterium, induced systemic resistance in cucumber against target leaf spot caused by Corynespora cassiicola. A cDNA library was constructed using mRNA extracted from cucumber leaves 12 h after inoculation with C. cassiicola, using plants colonized by O6. To identify genes involved in O6-mediated induced systemic resistance (ISR), we employed a subtractive hybridization method using mRNAs extracted from pathogen-challenged cucumber leaves of plants lacking colonization. Differential screening of the cDNA library led to the isolation of six distinct genes encoding a GTP binding protein, a 60S ribosomal protein, a hypersensitive-induced reaction protein, a ubiquitin extension protein, a pyridine nucleotide-disulfide oxidoreductase, and a signal recognition particle receptor. Expression of these genes was not induced by O6 colonization alone. Rather, transcript accumulation of these genes increased significantly faster and stronger in the O6 colonized than in non-colonized plants after challenge infection. Therefore, O6-mediated ISR may be associated with an enhanced capacity for the rapid and effective activation of cellular defence responses after challenge inoculation.

References

B. H. Cho

Division of Applied Plant Science
College of Agriculture and Life Sciences
Chonnam National University

Gwangju 500-757

South Korea

Email: chobh@chonnam.ac.kr

Section Editor: C. Pieterse