TY - JOUR A1 - Skirycz, Aleksandra A1 - Reichelt, Michael A1 - Burow, Meike A1 - Birkemeyer, Claudia Sabine A1 - Rolcik, Jacub A1 - Kopka, Joachim A1 - Zanor, Maria Ines A1 - Gershenzon, Jonathan A1 - Strnad, Miroslav A1 - Szopa, Jan A1 - Müller-Röber, Bernd A1 - Witt, Isabell T1 - DOF transcription factor AtDof1.1 (OBP2) is part of a regulatory network controlling glucosinolate biosynthesis in Arabidopsis N2 - Glucosinolates are a group of secondary metabolites that function as defense substances against herbivores and micro-organisms in the plant order Capparales. Indole glucosinolates (IGS), derivatives of tryptophan, may also influence plant growth and development. In Arabidopsis thaliana, indole-3-acetaldoxime (IAOx) produced from tryptophan by the activity of two cytochrome P450 enzymes, CYP79B2 and CYP79B3, serves as a precursor for IGS biosynthesis but is also an intermediate in the biosynthetic pathway of indole-3-acetic acid (IAA). Another cytochrome P450 enzyme, CYP83B1, funnels IAOx into IGS. Although there is increasing information about the genes involved in this biochemical pathway, their regulation is not fully understood. OBP2 has recently been identified as a member of the DNA-binding-with-one- finger (DOF) transcription factors, but its function has not been studied in detail so far. Here we report that OBP2 is expressed in the vasculature of all Arabidopsis organs, including leaves, roots, flower stalks and petals. OBP2 expression is induced in response to a generalist herbivore, Spodoptera littoralis, and by treatment with the plant signalling molecule methyl jasmonate, both of which also trigger IGS accumulation. Constitutive and inducible over- expression of OBP2 activates expression of CYP83B1. In addition, auxin concentration is increased in leaves and seedlings of OBP2 over-expression lines relative to wild-type, and plant size is diminished due to a reduction in cell size. RNA interference-mediated OBP2 blockade leads to reduced expression of CYP83B1. Collectively, these data provide evidence that OBP2 is part of a regulatory network that regulates glucosinolate biosynthesis in Arabidopsis Y1 - 2006 UR - http://onlinelibrary.wiley.com/doi/10.1111/j.1365-313X.2006.02767.x/full ER - TY - JOUR A1 - Devkar, Vikas A1 - Thirumalaikumar, Venkatesh P. A1 - Xue, Gang-Ping A1 - Vallarino, Jose G. A1 - Tureckova, Veronika A1 - Strnad, Miroslav A1 - Fernie, Alisdair R. A1 - Hoefgen, Rainer A1 - Mueller-Roeber, Bernd A1 - Balazadeh, Salma T1 - Multifaceted regulatory function of tomato SlTAF1 in the response to salinity stress JF - New phytologist : international journal of plant science N2 - Salinity stress limits plant growth and has a major impact on agricultural productivity. Here, we identify NAC transcription factor SlTAF1 as a regulator of salt tolerance in cultivated tomato (Solanum lycopersicum). While overexpression of SlTAF1 improves salinity tolerance compared with wild-type, lowering SlTAF1 expression causes stronger salinity-induced damage. Under salt stress, shoots of SlTAF1 knockdown plants accumulate more toxic Na+ ions, while SlTAF1 overexpressors accumulate less ions, in accordance with an altered expression of the Na+ transporter genes SlHKT1;1 and SlHKT1;2. Furthermore, stomatal conductance and pore area are increased in SlTAF1 knockdown plants during salinity stress, but decreased in SlTAF1 overexpressors. We identified stress-related transcription factor, abscisic acid metabolism and defence-related genes as potential direct targets of SlTAF1, correlating it with reactive oxygen species scavenging capacity and changes in hormonal response. Salinity-induced changes in tricarboxylic acid cycle intermediates and amino acids are more pronounced in SlTAF1 knockdown than wild-type plants, but less so in SlTAF1 overexpressors. The osmoprotectant proline accumulates more in SlTAF1 overexpressors than knockdown plants. In summary, SlTAF1 controls the tomato’s response to salinity stress by combating both osmotic stress and ion toxicity, highlighting this gene as a promising candidate for the future breeding of stress-tolerant crops. KW - abscisic acid (ABA) KW - ion homeostasis KW - NAC KW - proline KW - salt stress KW - SlTAF1 KW - transcription factors Y1 - 2019 U6 - https://doi.org/10.1111/nph.16247 SN - 0028-646X SN - 1469-8137 VL - 225 IS - 4 SP - 1681 EP - 1698 PB - Wiley CY - Hoboken ER -