Leucine zipper-containing WRKY proteins widen the spectrum of immediate early elicitor-induced WRKY transcription factors in parsley.
Two new WRKY transcription factors from parsley (Petroselinum crispum), WRKY4 and WRKY5, were isolated using the yeast one-hybrid system. In yeast, both proteins interacted sequence-specifically with W boxes (TTGACC) and activated transcription. They appear to contain functional leucine zippers, which increase their affinities for W boxes. Co-transfection experiments in parsley protoplasts confirmed their in vivo-binding specificity for W boxes. Elicitor-mediated expression of the WRKY5 gene, the first parsley member of the group III family of WRKY proteins, is extremely transient, with high mRNA levels occurring within a time window of less than 1 h. WRKY4 and -5, as well as the previously identified parsley transcription factors WRKY1 and -3, are encoded by immediate early elicitor-activated genes that differ in their sensitivity to cycloheximide (CHX) and their activation kinetics. We propose that a number of the pathways activated during the plant defense response require the induction of several distinct WRKY transcription factors with different DNA binding-site preferences to fine-tune the activation of a wide spectrum of target genes.
Cormack
Robert S
RS
Max-Planck-Institut für Züchtungsforschung, Abteilung Biochemie, Carl-von-Linné-Weg 10, D-50829 Köln, Germany.
Eulgem
Thomas
T
Rushton
Paul J
PJ
Köchner
Petra
P
Hahlbrock
Klaus
K
Somssich
Imre E
IE
D000595:Amino Acid Sequence; D001483:Base Sequence; D003513:Cycloheximide / Q000494:pharmacology; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000235:genetics*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017781:Genes, Immediate-Early; D017930:Genes, Reporter; D016350:Leucine Zippers; D008969:Molecular Sequence Data; D028528:Petroselinum / Q000235:genetics*; D010935:Plant Diseases / Q000209:etiology; D010940:Plant Proteins / Q000096:biosynthesis / Q000235:genetics*; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D012441:Saccharomyces cerevisiae / Q000235:genetics; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics*; D014162:Transfection
D004268:DNA-Binding Proteins; D010940:Plant Proteins; D011500:Protein Synthesis Inhibitors; D014157:Transcription Factors; D003513:Cycloheximide