UV-B signaling pathways and fluence rate dependent transcriptional regulation of ARIADNE12

Department of Applied Genetics and Cell Biology, BOKU-University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria.
Physiologia Plantarum (Impact Factor: 3.14). 12/2011; 145(4):527-39. DOI: 10.1111/j.1399-3054.2011.01561.x
Source: PubMed


ARI12 belongs to a family of 'RING between RING fingers' (RBR) domain proteins with E3 ligase activity (Eisenhaber et al. 2007). The Arabidopsis genome codes for 14 ARI genes and two pseudogenes (Mladek et al. 2003). Under standard growth conditions ARI12 is predominantly expressed in roots. In addition, ARI12 is strongly induced in leaves following exposure to ultraviolet (UV)-B radiation at dosages similar to those in areas under a reduced ozone layer. With quantitative reverse transcription polymerase chain reaction analyses and promoter:reporter constructs we show that the expression of ARI12 peaks 2-4 h after UV-B radiation exposure. To test if ARI12's transcriptional activation depends on key players of the UV-B signaling pathway, ARI12 expression was quantified in mutants of the ELONGATED HYPOCOTYL5 (HY5), HY5 HOMOLOG (HYH) and the UV RESISTANCE LOCUS8 (UVR8) genes. ARI12 transcription was reduced by 50-70% in hy5, hyh and hy5/hyh double mutants, but not in uvr8 mutants. However, under low fluence rate UV-B conditions ARI12 is not induced in these mutants. Our results show that ARI12 represents a downstream target of the low fluence rate UVR8/HY5/HYH UV-B signaling pathway while under high fluence rates its expression is regulated by the two bZIP transcription factors HY5 and HYH in an UVR8-independent manner.

Download full-text


Available from: Nina Chumak, Sep 29, 2015
73 Reads
  • Source
    • "The potential of UV-B damage has increased in the last decades, which is caused by the depletion of ozone layer by release of chlorofluorocarbons (Moan, 2001). In the literature, plant UV-B responses are defined by low dose radiation (below or at ambient level, lower than 1 μmol m-2 s-1) or high dose radiation (above ambient level, 1–3 μmol m-2 s-1 or above) and short term (usually from seconds to hours) or long-term (usually from hours to days; Brown and Jenkins, 2008; Lang-Mladek et al., 2012; Hideg et al., 2013). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Sunlight provides the necessary energy for plant growth via photosynthesis but high light and particular its integral ultraviolet (UV) part causes stress potentially leading to serious damage to DNA, proteins, and other cellular components. Plants show adaptation to environmental stresses, sometimes referred to as "plant memory." There is growing evidence that plants memorize exposure to biotic or abiotic stresses through epigenetic mechanisms at the cellular level. UV target genes such as CHALCONE SYNTHASE (CHS) respond immediately to UV treatment and studies of the recently identified UV-B receptor UV RESISTANCE LOCUS 8 (UVR8) confirm the expedite nature of UV signaling. Considering these findings, an UV memory seems redundant. However, several lines of evidence suggest that plants may develop an epigenetic memory of UV and light stress, but in comparison to other abiotic stresses there has been relatively little investigation. Here we summarize the state of knowledge about acclimation and adaptation of plants to UV light and discuss the possibility of chromatin based epigenetic memory.
    Frontiers in Plant Science 09/2014; 5:474. DOI:10.3389/fpls.2014.00474 · 3.95 Impact Factor
  • Source
    • "Response References a Gene regulation 1–10 UV-B tolerance 1–4 Flavonoid biosynthesis 1, 4, 6, 10, 13 Hypocotyl growth suppression 4, 12, 14 Leaf/epidermal cell expansion 4, 10, 11 Endoreduplication in epidermal cells 11 Stomata per epidermal cell 11 Entrainment of circadian clock 7 Increased photosynthetic efficiency 8 Tolerance of B. cinerea infection 13 a 1, Kliebenstein et al. (2002); 2, Brown et al. (2005); 3, Brown and Jenkins (2008); 4, Favory et al. (2009); 5, Brown et al. (2009); 6, Grüber et al. (2010); 7, Fehér et al. (2011); 8, Davey et al. (2012); 9, Lang-Mladek et al. (2012); 10, Morales et al. (2013); 11, Wargent et al. (2009); 12, Cloix et al. (2012); 13, Demkura and Ballaré (2012); 14, Huang et al. (2013). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Low doses of UV-B light (280 to 315 nm) elicit photomorphogenic responses in plants that modify biochemical composition, photosynthetic competence, morphogenesis, and defense. UV RESISTANCE LOCUS8 (UVR8) mediates photomorphogenic responses to UV-B by regulating transcription of a set of target genes. UVR8 differs from other known photoreceptors in that it uses specific Trp amino acids instead of a prosthetic chromophore for light absorption during UV-B photoreception. Absorption of UV-B dissociates the UVR8 dimer into monomers, initiating signal transduction through interaction with CONSTITUTIVELY PHOTOMORPHOGENIC1. However, much remains to be learned about the physiological role of UVR8 and its interaction with other signaling pathways, the molecular mechanism of UVR8 photoreception, how the UVR8 protein initiates signaling, how it is regulated, and how UVR8 regulates transcription of its target genes.
    The Plant Cell 01/2014; 26(1). DOI:10.1105/tpc.113.119446 · 9.34 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Solar UV-B radiation (280-315 nm) has long been recognized as having a rather diverse environmental role.
    Physiologia Plantarum 05/2012; 145(4):501-4. DOI:10.1111/j.1399-3054.2012.01656.x · 3.14 Impact Factor
Show more