title: Molecular interactions of the γ-clade homeodomain-leucine zipper class I transcription factors during the wheat response to water deficit.
abstract: The γ-clade of class I homeodomain-leucine zipper (HD-Zip I) transcription factors (TFs) constitute members which play a role in adapting plant growth to conditions of water deficit. Given the importance of wheat (Triticum aestivum L.) as a global food crop and the impact of water deficit upon grain yield, we focused on functional aspects of wheat drought responsive HD-Zip I TFs. While the wheat γ-clade HD-Zip I TFs share significant sequence similarities with homologous genes from other plants, the clade-specific features in transcriptional response to abiotic stress were detected. We demonstrate that wheat TaHDZipI-3, TaHDZipI-4, and TaHDZipI-5 genes respond differentially to a variety of abiotic stresses, and that proteins encoded by these genes exhibit pronounced differences in oligomerisation, strength of DNA binding, and trans-activation of an artificial promoter. Three-dimensional molecular modelling of the protein-DNA interface was conducted to address the ambiguity at the central nucleotide in the pseudo-palindromic cis-element CAATNATTG that is recognised by all three HD-Zip I proteins. The co-expression of these genes in the same plant tissues together with the ability of HD-Zip I TFs of the γ-clade to hetero-dimerise suggests a role in the regulatory mechanisms of HD-Zip I dependent transcription. Our findings highlight the complexity of TF networks involved in plant responses to water deficit. A better understanding of the molecular complexity at the protein level during crop responses to drought will enable adoption of efficient strategies for production of cereal plants with enhanced drought tolerance.
authors.affiliation: From the Australian Centre for Plant Functional Genomics, School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Glen Osmond, SA, 5064, Australia.|South Australian Research and Development Institute, Waite Campus, Glen Osmond, SA, 5064, Australia.
authors.forename: John C
authors.initials: JC
authors.lastname: Harris
authors.affiliation: From the Australian Centre for Plant Functional Genomics, School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Glen Osmond, SA, 5064, Australia.
authors.forename: Pradeep
authors.initials: P
authors.lastname: Sornaraj
authors.affiliation: From the Australian Centre for Plant Functional Genomics, School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Glen Osmond, SA, 5064, Australia.
authors.forename: Mathew
authors.initials: M
authors.lastname: Taylor
authors.affiliation: From the Australian Centre for Plant Functional Genomics, School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Glen Osmond, SA, 5064, Australia.
authors.forename: Natalia
authors.initials: N
authors.lastname: Bazanova
authors.affiliation: From the Australian Centre for Plant Functional Genomics, School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Glen Osmond, SA, 5064, Australia.
authors.forename: Ute
authors.initials: U
authors.lastname: Baumann
authors.affiliation: From the Australian Centre for Plant Functional Genomics, School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Glen Osmond, SA, 5064, Australia.
authors.forename: Ben
authors.initials: B
authors.lastname: Lovell
authors.affiliation: From the Australian Centre for Plant Functional Genomics, School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Glen Osmond, SA, 5064, Australia.
authors.forename: Peter
authors.initials: P
authors.lastname: Langridge
authors.affiliation: From the Australian Centre for Plant Functional Genomics, School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Glen Osmond, SA, 5064, Australia.
authors.forename: Sergiy
authors.initials: S
authors.lastname: Lopato
authors.affiliation: From the Australian Centre for Plant Functional Genomics, School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, Glen Osmond, SA, 5064, Australia. maria.hrmova@adelaide.edu.au.
authors.forename: Maria
authors.initials: M
authors.lastname: Hrmova
mesh_terms: D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D003198:Computer Simulation; D018744:DNA, Plant; D018506:Gene Expression Regulation, Plant / Q000502:physiology*; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D016350:Leucine Zippers / Q000502:physiology*; D008958:Models, Molecular; D010802:Phylogeny; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D011487:Protein Conformation; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014908:Triticum / Q000235:genetics / Q000378:metabolism*; D014867:Water / Q000378:metabolism*; D014868:Water Deprivation
chemical_list: D018744:DNA, Plant; D018398:Homeodomain Proteins; D018749:RNA, Plant; D014157:Transcription Factors; D014867:Water
keywords: Abiotic stress; DNA binding; Homeodomain leucine zipper; Homo- and hetero-dimerisation; Molecular modelling; Transcription factor networks