Molecular characterization of a thiJ-like gene in Chinese cabbage.
A cDNA clone for a salicylic acid-induced gene in Chinese cabbage (Brassica rapa subsp. pekinensis) was isolated and characterized. The cabbage gene encoding a protein of 392 amino acids contained a tandem array of two thiJ-like sequences. ThiJ is a thiamin biosynthesis enzyme that catalyzes the phosphorylation of hydroxymethylpyrimidine (HMP) to HMP monophosphate. Although the cabbage gene shows a similarity to bacterial thiJ genes, it also shares a similarity with the human DJ-1, a multifunctional protein that is involved in transcription regulation, male fertility, and parkinsonism. The cabbage thiJ-like gene is strongly induced by salicylic acid and a nonhost pathogen, Pseudomonas syringae pv. tomato, which elicits a hypersensitive response in Chinese cabbage. Treatment of the cabbage leaves with BTH, methyl jasmonate, or ethephon showed that the cabbage thiJ-like gene expression is also strongly induced by BTH, but not by methyl jasmonate or ethylene. This indicates that the cabbage gene is activated via a salicylic acid-dependent signaling pathway. Examination of the tissue-specific expression revealed that the induction of the cabbage gene expression by BTH occurs in the leaf, stem, and floral tissues but not in the root.
Oh
Kyung-Jin
KJ
Division of Life Sciences, College of Natural Sciences, Chungbuk National University, Cheongju 360-763, Korea.
Park
Yong-Soon
YS
Lee
Kyung-Ah
KA
Chung
Yong Je
YJ
Cho
Tae-Ju
TJ
D000595:Amino Acid Sequence; D001483:Base Sequence; D029741:Brassica rapa / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology; D018506:Gene Expression Regulation, Plant; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D010937:Plant Growth Regulators / Q000494:pharmacology; D018514:Plant Structures / Q000166:cytology / Q000378:metabolism; D044224:Pseudomonas syringae / Q000472:pathogenicity; D020156:Salicylic Acid / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D013831:Thiamine / Q000096:biosynthesis*
D010937:Plant Growth Regulators; D020156:Salicylic Acid; D013831:Thiamine