An HR-induced tobacco peroxidase gene is responsive to spermine, but not to salicylate, methyl jasmonate, and ethephon.
In Tobacco mosaic virus (TMV)-infected tobacco plants carrying the N resistance gene, a hypersensitive reaction or response (HR) occurs to enclose the virus in the infected tissue. Although a contribution of peroxidases to the resistance has been proposed, no evidence has been presented that tobacco peroxidase genes respond to HR. Here, we describe the HR-induced expression of a tobacco peroxidase gene (tpoxC1) whose induction kinetics were slightly different from those of acidic and basic tobacco pathogenesis-related (PR) protein genes. Interestingly, tpoxC1 was insensitive to the inducers of PR genes such as salicylic acid, methyl jasmonate, and ethephon. Spermine activated tpoxC1 gene expression at a low level and both acidic and basic PR gene expression at a considerably higher level. These results indicate that the induced expression of tpoxC1 is regulated differently from that of classical tobacco PR genes in the N gene-mediated self-defense system in tobacco plants.
Hiraga
S
S
Department of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Sapporo, Japan.
Ito
H
H
Yamakawa
H
H
Ohtsubo
N
N
Seo
S
S
Mitsuhara
I
I
Matsui
H
H
Honma
M
M
Ohashi
Y
Y
D000085:Acetates / Q000494:pharmacology; D003517:Cyclopentanes / Q000494:pharmacology; D017343:Genes, Plant / Q000187:drug effects; D009943:Organophosphorus Compounds / Q000494:pharmacology; D054883:Oxylipins; D010544:Peroxidases / Q000235:genetics*; D010937:Plant Growth Regulators / Q000494:pharmacology; D010947:Plants, Toxic; D020156:Salicylic Acid / Q000494:pharmacology; D013096:Spermine / Q000494:pharmacology; D014026:Nicotiana / Q000201:enzymology* / Q000235:genetics* / Q000821:virology; D014027:Tobacco Mosaic Virus / Q000472:pathogenicity
D000085:Acetates; D003517:Cyclopentanes; D009943:Organophosphorus Compounds; D054883:Oxylipins; D010937:Plant Growth Regulators; D013096:Spermine; C072239:methyl jasmonate; D010544:Peroxidases; D020156:Salicylic Acid; C005073:ethephon