TY  - JOUR
AU  - Janzik, I.
AU  - Preiskowski, S.
AU  - Kneifel, H.
TI  - Ozone has dramatic effects on the regulation of the prechorismate pathway in tobacco (Nicotiana tabacum L.cv. Bel W3)
JO  - Planta
VL  - 223
SN  - 0032-0935
CY  - Berlin
PB  - Springer
M1  - PreJuSER-45605
SP  - 20 - 27
PY  - 2005
N1  - Record converted from VDB: 12.11.2012
AB  - The accumulation of aromatic secondary metabolites is a well-known element of the plant response to ozone. Most of these metabolites are synthesized via the three aromatic amino acids phenylalanine, tyrosine and tryptophan. Before branching, the biosynthetic pathway to the three amino acids shares seven enzymatic steps, called the prechorismate pathway, catalysed by 3-deoxy-D: -arabino-heptulosonate-7-phosphate (DAHP) synthase [EC 2.5.1.54], 3-dehydroquinate synthase [EC 4.2.3.4], 3-dehydroquinate dehydratase [EC 4.2.1.10]-shikimate 5-dehydrogenase [EC 1.1.1.25], shikimate kinase [EC 2.7.1.71], 5-enolpyruvylshikimate 3-phosphate synthase [EC 2.5.1.19] and chorismate synthase [EC 4.2.3.5]). We have studied the transcript level of these enzymes and the aromatic metabolite profile in the ozone sensitive tobacco cultivar BelW3 (Nicotiana tabacum L. cv Bel W3), when exposed to an acute ozone pulse (160 nl l(-1), 5 h). Specific cDNA-fragments of the corresponding six genes were isolated from tobacco Bel W3 and used as probes for determining the expression of the prechorismate pathway genes. The fully expanded leaves of ozone treated plants, which developed symptoms like necrotic leaf spots and accumulation of aromatic metabolites, showed a clear induction of the shikimate pathway genes; indicating, that this induction is linked to the development of the symptoms. Distinct kinetics and magnitudes were observed in tobacco leaves for the ozone dependent enhanced mRNA accumulation of the aforementioned genes in BelW3. The strongest and earliest induction due to ozone treatment could be observed for DAHP synthase. An isoform-specific analysis of the transcripts showed a strong induction on transcript level only for one of three isoforms, which was followed by the induction of the DAHP synthase also on protein level. The different induction kinetics of the prechorismate pathway genes indicate that their regulation in response to ozone might be regulated by different signals, for example, ethylene, reactive oxygen species or salicylic acid, which also occur with different kinetics and thus may play different roles in the plant response to ozone.
KW  - 3-Deoxy-7-Phosphoheptulonate Synthase
KW  - Aldehyde-Lyases: biosynthesis
KW  - Aldehyde-Lyases: genetics
KW  - Amino Acids, Aromatic: biosynthesis
KW  - Blotting, Northern
KW  - Chorismic Acid: metabolism
KW  - Chromatography, High Pressure Liquid
KW  - DNA, Complementary
KW  - DNA, Plant
KW  - Enzyme Induction
KW  - Gene Expression Regulation, Enzymologic
KW  - Gene Expression Regulation, Plant
KW  - Ozone: pharmacology
KW  - Phosphotransferases (Alcohol Group Acceptor): metabolism
KW  - Plant Leaves
KW  - Tobacco: enzymology
KW  - Tobacco: genetics
KW  - Tobacco: metabolism
KW  - Amino Acids, Aromatic (NLM Chemicals)
KW  - DNA, Complementary (NLM Chemicals)
KW  - DNA, Plant (NLM Chemicals)
KW  - Ozone (NLM Chemicals)
KW  - Chorismic Acid (NLM Chemicals)
KW  - 3-Deoxy-7-Phosphoheptulonate Synthase (NLM Chemicals)
KW  - Phosphotransferases (Alcohol Group Acceptor) (NLM Chemicals)
KW  - shikimate kinase (NLM Chemicals)
KW  - Aldehyde-Lyases (NLM Chemicals)
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
C6  - pmid:16078071
UR  - <Go to ISI:>//WOS:000233725000003
DO  - DOI:10.1007/s00425-005-0060-8
UR  - https://juser.fz-juelich.de/record/45605
ER  -