Dawn and photoperiod sensing by phytochrome A

Seaton, Daniel D.,Toledo-Ortiz, Gabriela,Ganpudi, Ashwin,Kubota, Akane,Imaizumi, Takato,Halliday, Karen J. National Academy of Sciences 2018 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.115 No.41

<P><B>Significance</B></P><P>The changing seasons subject plants to a variety of challenging environments. To deal with this, many plants have mechanisms for inferring the season by measuring the duration of daylight in a day. A number of well-known seasonal responses such as flowering are responsive to daylength or photoperiod. Here, we describe how the photoreceptor protein phytochrome A senses short photoperiods. This arises from its accumulation during long nights, as happens during winter, and subsequent activation by light at dawn. As a result of this response, the abundance of red anthocyanin pigments is increased in short photoperiods. Thus, we describe a mechanism underlying a seasonal phenotype in an important model plant species.</P><P>In plants, light receptors play a pivotal role in photoperiod sensing, enabling them to track seasonal progression. Photoperiod sensing arises from an interaction between the plant’s endogenous circadian oscillator and external light cues. Here, we characterize the role of phytochrome A (phyA) in photoperiod sensing. Our metaanalysis of functional genomic datasets identified phyA as a principal regulator of morning-activated genes, specifically in short photoperiods. We demonstrate that <I>PHYA</I> expression is under the direct control of the PHYTOCHROME INTERACTING FACTOR transcription factors, PIF4 and PIF5. As a result, phyA protein accumulates during the night, especially in short photoperiods. At dawn, phyA activation by light results in a burst of gene expression, with consequences for physiological processes such as anthocyanin accumulation. The combination of complex regulation of <I>PHYA</I> transcript and the unique molecular properties of phyA protein make this pathway a sensitive detector of both dawn and photoperiod.</P>

Vase Life and Root Propagation of Geraldton Wax (Chamelaucium spp.) Cut Flowers Treated with Glyphosate

Kevin Seaton,Kok Lee,Beng Tan 한국원예학회 2010 Horticulture, Environment, and Biotechnology Vol.51 No.6

Glyphosate [N-(phosphonomethy)glycine] as Roundup<SUP>?</SUP> (360 g · L?¹ a.i.) can render cuttings taken from cut flowers inert and unable to be propagated. It may also affect other plant physiological processes such as the vase life. In this study the effects of glyphosate on vase life and root propagation of cutting taken from cut flowers of Geraldton wax varieties ‘Purple Pride’ (Chamelaucium uncinatum), and ‘Bridal Pearl’ and ‘Albany Pearl’ (C. uncinatum × C. megalopetalum hybrids) were investigated. Cuttings of ‘Purple Pride’ pulsed in a 0.1% Roundup<SUP>?</SUP> (0.36 g · L?¹ glyphosate) solution for 20 minutes failed to produce roots and were dry within 28 days; leaf vase-life also increased by three days with no adverse effect on flower vase life, normally evidenced by accelerated senescence and petal closure. Pulsing in a 1% Roundup<SUP>?</SUP> (3.6 g · L?¹ glyphosate) or 10% Roundup<SUP>?</SUP> (36 g · L?¹ glyphosate) solution for 20 minutes increased flower vase life by 3 to 5 days. Pulsing in Roundup<SUP>?</SUP> solutions for longer durations at these concentrations did not decrease flower vase life below the control, but leaf vase life was reduced from 10 days (control) to between 4 (1% Roundup<SUP>?</SUP> 120 minutes) and 7 days (10% Roundup<SUP>?</SUP> for 60 minutes). A similar result was also found for ‘Bridal Pearl’ except that there was no improvement in flower vase life following a 20 minute pulse in a 0.1% Roundup<SUP>?</SUP> solution. No roots occurred in cuttings taken from flowering stems of ‘Albany Pearl’ pulsed in a 0.1% Roundup<SUP>?</SUP> solution for 20 minutes at 20℃ or immersed in a 0.25% Roundup<SUP>?</SUP> solution for one minute. There was also no reduction in vase life of flowers and leaves of sprigs taken from stems pulsed or immersed in these Roundup<SUP>?</SUP> solutions. A protocol using a 0.1% Roundup<SUP>?</SUP> solution as a 20 minute pulse or a stronger 0.25% Roundup<SUP>?</SUP> solution as a 1-minute immersion should provide an effective postharvest treatment to prevent propagation of cuttings taken from Geraldton wax cut flowers.

The Centenary of the Annexation of Korea in the Japanese Media

필립시튼 ( Philip Seaton ) 국민대학교 일본학연구소 2011 일본공간 Vol.9 No.-

간나오토 수상은 한일병합 100년에 있어 일본의 한반도 식민지 지배에 관한 사죄담화를 발표했다. 본고는 2010년 8월에 발표된 한일병합 100년에 대한 일본 매스미디어의 보도를 분석하고, 한일관계 보도에 보여진 1965년 한일기본조약에 대한 이해방식을 고찰하는 것으로, 미디어와 권리, 두 가지 주요개념에 초점을 맞추어 이론적 구조를 제시하고 있다. 한일기본조약에 대한 NHK 다큐멘터리 방송(2010년 8월 1일 방영)에 있어 1965년의 유산에 대한 논의를 분석하고, 이어 다음의 세 가지 미디어를 분석했다. 1) 8월 10일 간담화에 대한 각 TV, 신문보도, 2) 한일관계에 대한 TV토론(8월 14일 방영), 3) 8월 29일 기념일에 대한 각 보도. 이러한 분석 결과, 미디어는 동아시아에 있어 역사문제의 옵져버임과 동시에, 역사문제를 둘러싼 논의를 구축하고 그것을 과열시켜 간다는 점에서 큰 역할을 하고 있는 것이 명확해졌다. 또한 본고에서는 일본의 책임문제보다도 권리에 초점을 맞추어, 많은 일반 한국 국민이 전후 조정에 있어 한국 정부의 역할에 실망하고 있다는 사실을 명확히 했다. To mark the one hundredth anniversary of Japan`s annexation of Korea, Prime Minister Kan Naoto issued a statement (danwa) apologizing for Japan`s colonial rule over Korea, 1910-45. This paper analyzes how Japanese television and the quality press covered the centenary commemorations in August 2010, and assesses the legacies of the 1965 Treaty on Basic Relations for contemporary media coverage of Korean-Japanese relations. It presents a theoretical framework focusing on two key concepts: ‘media’ and ‘rights’. The ‘legacies of 1965’ are introduced via discussion of an NHK documentary about the Treaty (broadcast on 1 August 2010). This is followed by analysis of three media events: 1) news coverage on television and in the press of the 10 August statement by Prime Minister Kan; 2) a television studio discussion of Korean-Japanese relations (broadcast on 14 August); and 3) news coverage of the 29 August anniversary. The paper demonstrates how the media is not simply an observer of the ‘history issue’ (rekishi mondai) in East Asia, but plays a key role in shaping and stoking debates over history. The focus on rights rather than (Japanese) responsibility illuminates the Korean government’s role in creating a postwar settlement that continues to leave many ordinary Korean people dissatisfied.

The JAK/STAT Pathway Is Involved in Synaptic Plasticity

Nicolas, Cé,line ,S.,Peineau, Sté,phane,Amici, Mascia,Csaba, Zsolt,Fafouri, Assia,Javalet, Charlotte,Collett, Valerie ,J.,Hildebrandt, Lars,Seaton, Gillian,Choi, Sun-Lim,Sim, Su-Eo Cell Press 2012 Neuron Vol.73 No.2

<▼1><P><B>Summary</B></P><P>The Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway is involved in many cellular processes, including cell growth and differentiation, immune functions and cancer. It is activated by various cytokines, growth factors, and protein tyrosine kinases (PTKs) and regulates the transcription of many genes. Of the four JAK isoforms and seven STAT isoforms known, JAK2 and STAT3 are highly expressed in the brain where they are present in the postsynaptic density (PSD). Here, we demonstrate a new neuronal function for the JAK/STAT pathway. Using a variety of complementary approaches, we show that the JAK/STAT pathway plays an essential role in the induction of NMDA-receptor dependent long-term depression (NMDAR-LTD) in the hippocampus. Therefore, in addition to established roles in cytokine signaling, the JAK/STAT pathway is involved in synaptic plasticity in the brain.</P></▼1><▼2><P>The authors demonstrate a new neuronal function for the JAK/STAT pathway in the induction of NMDA-receptor-dependent long-term depression (NMDAR-LTD) in the hippocampus.</P></▼2>