Tobacco genes encoding acidic and basic isoforms of pathogenesis-related proteins display different expression patterns.
The induction by cytokinin stress and ethylene of nine different tobacco mosaic virus-inducible mRNA classes (termed A-I) encoding pathogenesis-related (PR) proteins was studied. The induced mRNA levels were compared to basal levels in healthy tobacco plants grown in tissue culture and in a greenhouse. Cytokinin stress and ethylene were found to induce different subsets of the mRNAs, indicating that ethylene is not the primary inducing signal in cytokinin-stressed shoots. mRNAs F, H and G encoding the basic hydrolytic enzymes chitinase, beta-1,3-glucanase and a basic equivalent of PR-1, respectively, were found to be expressed at high levels in roots of healthy plants. mRNAs D, I and B encoding the acidic equivalents of the proteins proved to be present at low levels in healthy plants. These results indicate that genes encoding basic and acidic isoforms of pathogenesis-related proteins are differentially regulated.
Memelink
J
J
Molbas Research Group, Department of Plant Molecular Biology, Leiden University, Netherlands.
Linthorst
H J
HJ
Schilperoort
R A
RA
Hoge
J H
JH
D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000235:genetics; D015870:Gene Expression; D017343:Genes, Plant; D008027:Light; D009693:Nucleic Acid Hybridization; D010940:Plant Proteins / Q000235:genetics*; D010947:Plants, Toxic; D012333:RNA, Messenger / Q000235:genetics / Q000302:isolation & purification; D014026:Nicotiana / Q000235:genetics* / Q000382:microbiology; D014027:Tobacco Mosaic Virus / Q000235:genetics* / Q000472:pathogenicity; D014170:Transformation, Genetic
D004269:DNA, Bacterial; D010940:Plant Proteins; D012333:RNA, Messenger; C036483:T-DNA; C053376:pathogenesis-related proteins, plant