title: Early induction of the Arabidopsis GSTF8 promoter by specific strains of the fungal pathogen Rhizoctonia solani.
abstract: The Arabidopsis glutathione S-transferase GSTF8 promoter directs root-specific responses to stress. In this study, the response of this promoter to plant infection with Rhizoctonia solani was investigated using a luciferase reporter system. Arabidopsis seedlings harboring the GSTF8:luciferase construct were monitored in vivo for bioluminescence following infection with R. solani. Although the reporter gene was induced in infected roots, the response differed markedly between R. solani strains and was not observed with aggressive strains that caused death of the seedlings. The three strains tested in detail progressed through typical stages of infection, but ZG1-1 induced the GSTF8 promoter in most seedlings, ZG3 induced it in approximately 25% of seedlings, and ZG5 caused little response. Induction of specific root segments occurred early in the infection process in root regions with very limited mycelium visible. In root segments with substantial mycelium, GSTF8 promoter activity no longer was observed. Induction by ZG1-1 also was observed in plants harboring a tetramer of the ocs element from the GSTF8 promoter, suggesting that this element helps mediate the response. Crossing GSTF8:luciferase plants with plants harboring an Nah-G construct that degrades salicylic acid did not abolish the response, indicating that the GSTF8 promoter response to R. solani may be mediated by signals other than salicylic acid.
authors.affiliation: CSIRO Plant Industry, Private Bag 5, PO Wembley, WA 6913, Australia.
authors.forename: Rafael
authors.initials: R
authors.lastname: Perl-Treves
authors.forename: Rhonda C
authors.initials: RC
authors.lastname: Foley
authors.forename: Wenqiong
authors.initials: W
authors.lastname: Chen
authors.forename: Karam B
authors.initials: KB
authors.lastname: Singh
mesh_terms: D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics* / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D046508:Culture Techniques; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D005982:Glutathione Transferase / Q000235:genetics* / Q000378:metabolism; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D008163:Luminescent Measurements; D025282:Mycelium / Q000254:growth & development; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology; D018517:Plant Roots / Q000166:cytology / Q000382:microbiology; D011549:Pseudomonas / Q000254:growth & development; D012232:Rhizoctonia / Q000254:growth & development*; D020156:Salicylic Acid / Q000378:metabolism; D012988:Soil Microbiology; D013379:Substrate Specificity
chemical_list: D029681:Arabidopsis Proteins; D008156:Luciferases; C483103:GSTF8 protein, Arabidopsis; D005982:Glutathione Transferase; D020156:Salicylic Acid