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.
Division of Life Sciences, College of Natural Sciences, Chungbuk National University, Cheongju 360-763, Korea.
Kyung-Jin
KJ
Oh
Yong-Soon
YS
Park
Kyung-Ah
KA
Lee
Yong Je
YJ
Chung
Tae-Ju
TJ
Cho
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