title: Complex regulation by Apetala2 domain-containing transcription factors revealed through analysis of the stress-responsive TdCor410b promoter from durum wheat.
abstract: Expression of the wheat dehydrin gene Cor410b is induced several fold above its non-stressed levels upon exposure to stresses such as cold, drought and wounding. Deletion analysis of the TdCor410b promoter revealed a single functional C-repeat (CRT) element. Seven transcription factors (TFs) were shown to bind to this CRT element using yeast one-hybrid screens of wheat and barley cDNA libraries, of which only one belonged to the DREB class of TFs. The remaining six encoded ethylene response factors (ERFs) belong to three separate subfamilies. Analysis of binding selectivity of these TFs indicated that all seven could bind to the CRT element (GCCGAC), and that three of the six ERFs could bind both to the CRT element and the ethylene-responsive GCC-box (GCCGCC). The TaERF4 subfamily members specifically bound the CRT element, and did not bind either the GCC-box or DRE element (ACCGAC). Molecular modeling and site-directed mutagenesis identified a single residue Pro42 in the Apetala2 (AP2) domain of TaERF4-like proteins that is conserved in monocotyledonous plants and is responsible for the recognition selectivity of this subfamily. We suggest that both DREB and ERF proteins regulate expression of the Cor410b gene through a single, critical CRT element. Members of the TaERF4 subfamily are specific, positive regulators of Cor410b gene expression.
authors.affiliation: Australian Centre for Plant Functional Genomics, University of Adelaide, Glen Osmond, South Australia, Australia.
authors.forename: Omid
authors.initials: O
authors.lastname: Eini
authors.forename: Nannan
authors.initials: N
authors.lastname: Yang
authors.forename: Tatiana
authors.initials: T
authors.lastname: Pyvovarenko
authors.forename: Katherine
authors.initials: K
authors.lastname: Pillman
authors.forename: Natalia
authors.initials: N
authors.lastname: Bazanova
authors.forename: Natalia
authors.initials: N
authors.lastname: Tikhomirov
authors.forename: Serik
authors.initials: S
authors.lastname: Eliby
authors.forename: Neil
authors.initials: N
authors.lastname: Shirley
authors.forename: Shoba
authors.initials: S
authors.lastname: Sivasankar
authors.forename: Scott
authors.initials: S
authors.lastname: Tingey
authors.forename: Peter
authors.initials: P
authors.lastname: Langridge
authors.forename: Maria
authors.initials: M
authors.lastname: Hrmova
authors.forename: Sergiy
authors.initials: S
authors.lastname: Lopato
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D018744:DNA, Plant / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic; D017386:Sequence Homology, Amino Acid; D013312:Stress, Physiological; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D014908:Triticum / Q000235:genetics* / Q000378:metabolism
chemical_list: D018744:DNA, Plant; D010940:Plant Proteins; D014157:Transcription Factors