title: Abiotic stress upregulated TaZFP34 represses the expression of type-B response regulator and SHY2 genes and enhances root to shoot ratio in wheat.
abstract: Q-type C2H2zinc finger proteins (ZFPs) are plant-specific DNA-binding proteins containing a conserved QALGGH motif. This study investigated the function of abiotic stress-inducible and predominantly root-expressed Triticum aestivum ZFPs (TaZFP22, TaZFP34 and TaZFP46) with a focus on TaZFP34. Expression of TaZFP34 in roots was upregulated by high salinity, dehydration, oxidative and cold stresses. Overexpression of TaZFP34 in wheat roots resulted in an increased root-to-shoot ratio, a phenomenon observed during plant adaptation to drying soil. Expression of a number of genes which are potentially involved in modulating root growth was significantly altered in the roots of TaZFP34 overexpressing lines. In particular, the transcript levels of TaRR12B, TaRR12D and TaSHY2 that are homologues of known negative regulators of root growth were significantly reduced. Expression of shoot growth-related genes, such as GA3-ox and expansins, was downregulated in the transgenic shoots. TaZFP34 bound to (C/G)AGT(G/A)-like elements in the promoters of TaZFP34 down-regulated TaRR12D and TaSHY2 and transrepressed the reporter gene expression driven by TaRR12D and TaSHY2 promoters. Expression of the above reporter genes was also repressed by TaZFP46 and TaZFP22. These data suggest that TaZFP34 is a transcriptional repressor and is involved in modulating the root-to-shoot ratio.
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, Hunan University, Changsha 410082, PR China; CSIRO Agriculture, 306 Carmody Rd., St Lucia, QLD 4067, Australia. Electronic address: Hongping.chang@csiro.au.
authors.forename: Hongping
authors.initials: H
authors.lastname: Chang
authors.affiliation: College of Agronomy, Northwest Agriculture and Forestry University, Yangling, Shaanxi 712100, PR China; CSIRO Agriculture, 306 Carmody Rd., St Lucia, QLD 4067, Australia. Electronic address: dandan.chen@csiro.au.
authors.forename: Dandan
authors.initials: D
authors.lastname: Chen
authors.affiliation: Institute of Biological, Environmental & Rural Sciences, Aberystwyth University, Ceredigion, Wales SY23 3EB, UK. Electronic address: jak42@aber.ac.uk.
authors.forename: Jason
authors.initials: J
authors.lastname: Kam
authors.affiliation: CSIRO Agriculture, Clunies Ross Street, Canberra, ACT 2601, Australia. Electronic address: terese.richardson@csiro.au.
authors.forename: Terese
authors.initials: T
authors.lastname: Richardson
authors.affiliation: CSIRO Agriculture, 306 Carmody Rd., St Lucia, QLD 4067, Australia. Electronic address: Janneke.drenth@csiro.au.
authors.forename: Janneke
authors.initials: J
authors.lastname: Drenth
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, Hunan University, Changsha 410082, PR China. Electronic address: gxh@hnu.edu.cn.
authors.forename: Xinhong
authors.initials: X
authors.lastname: Guo
authors.affiliation: CSIRO Agriculture, 306 Carmody Rd., St Lucia, QLD 4067, Australia. Electronic address: lynne.mcintyre@csiro.au.
authors.forename: C Lynne
authors.initials: CL
authors.lastname: McIntyre
authors.affiliation: College of Agronomy, Northwest Agriculture and Forestry University, Yangling, Shaanxi 712100, PR China. Electronic address: chaishoucheng@126.com.
authors.forename: Shoucheng
authors.initials: S
authors.lastname: Chai
authors.affiliation: CSIRO Agriculture, 306 Carmody Rd., St Lucia, QLD 4067, Australia. Electronic address: anne.rae@csiro.au.
authors.forename: Anne L
authors.initials: AL
authors.lastname: Rae
authors.affiliation: CSIRO Agriculture, 306 Carmody Rd., St Lucia, QLD 4067, Australia. Electronic address: gang-ping.xue@csiro.au.
authors.forename: Gang-Ping
authors.initials: GP
authors.lastname: Xue
mesh_terms: D000222:Adaptation, Physiological; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D055864:Droughts; D018506:Gene Expression Regulation, Plant; D017930:Genes, Reporter; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D018517:Plant Roots / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D018520:Plant Shoots / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D013312:Stress, Physiological; D014908:Triticum / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D015854:Up-Regulation; D014867:Water / Q000378:metabolism
chemical_list: D004268:DNA-Binding Proteins; D010940:Plant Proteins; D014867:Water
keywords: C(2)H(2) zinc finger proteins; Drought stress; Root and shoot growth; Root-specific expression; Transcriptional repressor; Wheat