scholarly journals Novel light-regulated genes in Trichoderma atroviride: a dissection by cDNA microarrays

Microbiology ◽  
2006 ◽  
Vol 152 (11) ◽  
pp. 3305-3317 ◽  
Author(s):  
T. Rosales-Saavedra ◽  
E. U. Esquivel-Naranjo ◽  
S. Casas-Flores ◽  
P. Martínez-Hernández ◽  
E. Ibarra-Laclette ◽  
...  
Keyword(s):  
Red Light ◽  
Continuous Light ◽  
Soil Fungus ◽  
Light Response ◽  
Trichoderma Atroviride ◽  
Light Responses ◽  
The Common ◽  
Living Organisms ◽  
Regulated Gene Expression

The influence of light on living organisms is critical, not only because of its importance as the main source of energy for the biosphere, but also due to its capacity to induce changes in the behaviour and morphology of nearly all forms of life. The common soil fungus Trichoderma atroviride responds to blue light in a synchronized manner, in time and space, by forming a ring of green conidia at what had been the colony perimeter at the time of exposure (photoconidiation). A putative complex formed by the BLR-1 and BLR-2 proteins in T. atroviride appears to play an essential role as a sensor and transcriptional regulator in photoconidiation. Expression analyses using microarrays containing 1438 unigenes were carried out in order to identify early light response genes. It was found that 2.8 % of the genes were light responsive: 2 % induced and 0.8 % repressed. Expression analysis in blr deletion mutants allowed the demonstration of the occurrence of two types of light responses, a blr-independent response in addition to the expected blr-dependent one, as well as a new role of the BLR proteins in repression of transcription. Exposure of T. atroviride to continuous light helped to establish that the light-responsive genes are subject to photoadaptation. Finally, evidence is provided of red-light-regulated gene expression and a possible crosstalk between the blue and red light signalling pathways.

scholarly journals On the (un)coupling of the chromophore, tongue interactions, and overall conformation in a bacterial phytochrome

2018 ◽  
Vol 293 (21) ◽  
pp. 8161-8172 ◽  
Author(s):  
Heikki Takala ◽  
Heli K. Lehtivuori ◽  
Oskar Berntsson ◽  
Ashley Hughes ◽  
Rahul Nanekar ◽  
...  
Keyword(s):  
Conformational Changes ◽  
Structural Changes ◽  
Deinococcus Radiodurans ◽  
Red Light ◽  
Light Responses ◽  
Structural Mechanism ◽  
Weakly Coupled ◽  
Activity State ◽  
Conserved Tyrosine

Phytochromes are photoreceptors in plants, fungi, and various microorganisms and cycle between metastable red light–absorbing (Pr) and far-red light–absorbing (Pfr) states. Their light responses are thought to follow a conserved structural mechanism that is triggered by isomerization of the chromophore. Downstream structural changes involve refolding of the so-called tongue extension of the phytochrome-specific GAF-related (PHY) domain of the photoreceptor. The tongue is connected to the chromophore by conserved DIP and PRXSF motifs and a conserved tyrosine, but the role of these residues in signal transduction is not clear. Here, we examine the tongue interactions and their interplay with the chromophore by substituting the conserved tyrosine (Tyr263) in the phytochrome from the extremophile bacterium Deinococcus radiodurans with phenylalanine. Using optical and FTIR spectroscopy, X-ray solution scattering, and crystallography of chromophore-binding domain (CBD) and CBD–PHY fragments, we show that the absence of the Tyr263 hydroxyl destabilizes the β-sheet conformation of the tongue. This allowed the phytochrome to adopt an α-helical tongue conformation regardless of the chromophore state, hence distorting the activity state of the protein. Our crystal structures further revealed that water interactions are missing in the Y263F mutant, correlating with a decrease of the photoconversion yield and underpinning the functional role of Tyr263 in phytochrome conformational changes. We propose a model in which isomerization of the chromophore, refolding of the tongue, and globular conformational changes are represented as weakly coupled equilibria. The results also suggest that the phytochromes have several redundant signaling routes.

scholarly journals A Multifaceted Action of Phytochrome B in Plant Environmental Adaptation

2021 ◽  
Vol 12 ◽  
Author(s):  
Jae Young Kim ◽  
June-Hee Lee ◽  
Chung-Mo Park
Keyword(s):  
Red Light ◽  
Environmental Adaptation ◽  
Signaling Cascades ◽  
Adaptive Behaviors ◽  
Environmental Cues ◽  
Plant Responses ◽  
Light Illumination ◽  
Light Responses ◽  
And Performance

Light acts as a vital external cue that conveys surrounding information into plant growth and performance to facilitate plants to coordinate with changing environmental conditions. Upon exposure to light illumination, plants trigger a burst of molecular and physiological signaling cascades that induces not only photomorphogenic responses but also diverse adaptive behaviors. Notably, light responses and photomorphogenic traits are often associated with plant responses to other environmental cues, such as heat, cold, drought, and herbivore and pathogen attack. Growing evidence in recent years demonstrate that the red/far-red light-absorbing phytochrome (phy) photoreceptors, in particular phyB, play an essential role in plant adaptation responses to abiotic and biotic tensions by serving as a key mediator of information flow. It is also remarkable that phyB mediates the plant priming responses to numerous environmental challenges. In this minireview, we highlight recent advances on the multifaceted role of phyB during plant environmental adaptation. We also discuss the biological relevance and efficiency of the phy-mediated adaptive behaviors in potentially reducing fitness costs under unfavorable environments.

scholarly journals PhyB induces intron retention and uORF-mediated translational inhibition of PIF3

2019 ◽  
Author(s):  
Jie Dong ◽  
Haodong Chen ◽  
Xing Wang Deng ◽  
Vivian F. Irish ◽  
Ning Wei
Keyword(s):  
Alternative Splicing ◽  
Protein Degradation ◽  
Intron Retention ◽  
Red Light ◽  
Light Response ◽  
Protein Translation ◽  
Light Cycle ◽  
Light Responses ◽  
E3 Ligases ◽  
Short Day

AbstractThe phytochrome B (phyB) photoreceptor stimulates light responses in plants in part by inactivating repressors of light responses such as phytochrome-interacting factor 3 (PIF3). It has been established that activated phyB inhibits PIF3 by rapid protein degradation and decreased transcription. PIF3 protein degradation has been shown to be mediated by EIN3-BINDING F-BOX PROTEIN (EBF) and LIGHT-RESPONSE BTB (LRB) E3 ligases, the latter simultaneously targeting phyB for degradation. In this study, we show that PIF3 level is additionally regulated by alternative splicing and protein translation. Overaccumulation of photo-activated phyB, which occur in the mutant defective for LRB genes under continuous red light (Rc), induces a specific alternative splicing of PIF3 that results in retention of an intron in the 5’UTR of PIF3 mRNA. In turn, the upstream opening reading frames (uORF) contained within this intron inhibit PIF3 protein synthesis. The phyB-dependent alternative splicing of PIF3 is diurnally regulated under the short-day light cycle. We hypothesize that this reversible regulatory mechanism may be utilized to fine-tune the level of PIF3 protein in light-grown plants, and may contribute to the oscillation of PIF3 protein abundance under the short-day environment.One Sentence SummaryLight down-regulates PIF3 by multiple mechanisms. We show that phyB induces an alternative splicing event that inhibits PIF3 protein translation, and that is regulated by short-day diurnal cycle.

scholarly journals Hinge region of Arabidopsis phyA plays an important role in regulating phyA function

2018 ◽  
Vol 115 (50) ◽  
pp. E11864-E11873 ◽  
Author(s):  
Yangyang Zhou ◽  
Li Yang ◽  
Jie Duan ◽  
Jinkui Cheng ◽  
Yunping Shen ◽  
...  
Keyword(s):  
Light Exposure ◽  
Red Light ◽  
Light Response ◽  
Hinge Region ◽  
Phytochrome A ◽  
Serine Residue ◽  
Signal Transducers ◽  
And Function

Phytochrome A (phyA) is the only plant photoreceptor that perceives far-red light and then mediates various responses to this signal. Phosphorylation and dephosphorylation of oat phyA have been extensively studied, and it was shown that phosphorylation of a serine residue in the hinge region of oat phyA could regulate the interaction of phyA with its signal transducers. However, little is known about the role of the hinge region of Arabidopsis phyA. Here, we report that three sites in the hinge region of Arabidopsis phyA (i.e., S590, T593, and S602) are essential in regulating phyA function. Mutating all three of these sites to either alanines or aspartic acids impaired phyA function, changed the interactions of mutant phyA with FHY1 and FHL, and delayed the degradation of mutant phyA upon light exposure. Moreover, the in vivo formation of a phosphorylated phyA form was greatly affected by these mutations, while our data indicated that the abundance of this phosphorylated phyA form correlated well with the extent of phyA function, thus suggesting a pivotal role of the phosphorylated phyA in inducing the far-red light response. Taking these data together, our study reveals the important role of the hinge region of Arabidopsis phyA in regulating phyA phosphorylation and function, thus linking specific residues in the hinge region to the regulatory mechanisms of phyA phosphorylation.

scholarly journals CURCUMIN ATTENUATES LEAD (Pb)–INDUCED NEUROBEHAVIORL AND NEUROBIOCHEMICAL DYSFUNCTION: A REVIEW

2018 ◽  
Vol 10 (8) ◽  
pp. 23 ◽  
Author(s):  
Gasem Mohammad Abu-taweel
Keyword(s):  
Chemical Elements ◽  
Curcuma Longa ◽  
Lead Toxicity ◽  
Neurotransmitter System ◽  
Behavioral Toxicity ◽  
Behavior Modifications ◽  
The Common ◽  
Living Organisms ◽  
The Brain

Lead is one of the common chemical elements that is assigned the symbol Pb which came from the Latin Plumbum. Pb is widely used in the field of coating, refine and glaze ceramics and pottery. It is still used in the production of products like water pipes, cooking utensils and cooking utensils. In addition it is also used in insulation of building ceilings, cable coverage and military industries. Lead enter the environment from those uses and from the environment it enter into the living organisms. Lead accumulates in many humanorgans, but the brain is the target organ of lead accumulation. Neurotoxicity of lead is, one of lead toxicity, caused many symptoms. There are many behavioral and biochemical modifications induced by lead toxicity like learning and memory deficits, anxiety disorders, social and sexual behavior modifications and neurotransmitter system deficits. Curcumin is a bioactive natural phytochemical phenolic compound (diferuloylmethane) extracted from the rhizome of Curcuma longa. Most studies indicated the role of curcumin in reducing the damage of lead toxicity. In the current review, emphasis was based on the toxicity of lead and its effect on behavior and some neurotransmitters related to behavior. The effect of curcumin is improving the neurotoxicity and behavioral toxicity of lead.

On everyday academic research

2017 ◽  
pp. 98-134 ◽  
Author(s):  
J. Tirole
Keyword(s):  
Common Good ◽  
Academic Research ◽  
Research Quality ◽  
Economic Research ◽  
Relevant Research ◽  
The Common ◽  
Verification Of Models ◽  
Science And Research

In the fourth chapter of the book “The economy of the common good”, the nature of economics as a science and research practices in their theoretical and empirical aspects are discussed. The author considers the processes of modeling, empirical verification of models and evaluation of research quality. In addition, the features of economic cognition and the role of mathematics in economic research are analyzed, including the example of relevant research in game theory and information theory.

Contemplative Principles of a Non-dual Praxis: the Unmediated Practices of the Tibetan ‘Heart Essence’ (sNying thig) Tradition

2015 ◽  
Vol 31 (2) ◽  
pp. 215-240
Author(s):  
Eran Laish
Keyword(s):  
Contemplative Practice ◽  
Tibetan Buddhist ◽  
Buddhist Tradition ◽  
The Common

This article focuses on the main contemplative principles of the ‘Heart Essence’ (sNying thig), a Tibetan Buddhist tradition that is characterized by a vision of non-duality and primordial wholeness. Due to this vision, which asserts an original reality that is not divided into perceiving subject and perceived object, the ‘Heart Essence’ advocates a contemplative practice that undermines the usual intuitions of temporality and enclosed selfhood. Hence, unlike the common principles of intentional praxis, such as deliberate concentration and gradual purification, the ‘Heart Essence’ affirms four contemplative principles of non-objectiveness, openness, spontaneity and singleness. As these principles transcend intentionality, temporality, and multiplicity, they are seen to directly disclose the nature of primordial awareness, in which the meanings of knowing and being are radically transformed. Therefore, the article will also consider the role of these non-dual contemplative principles in deeply changing our understanding of being and knowing alike.

Charles de Gaulle and European Community

2020 ◽  
Vol 2020 (10-3) ◽  
pp. 70-81
Author(s):  
David Ramiro Troitino ◽  
Tanel Kerikmae ◽  
Olga Shumilo
Keyword(s):  
World War Ii ◽  
European Community ◽  
World War ◽  
Charles De Gaulle ◽  
The United Kingdom ◽  
History Of ◽  
The Common ◽  
Post War ◽  
De Gaulle

This article highlights the role of Charles de Gaulle in the history of united post-war Europe, his approaches to the internal and foreign French policies, also vetoing the membership of the United Kingdom in the European Community. The authors describe the emergence of De Gaulle as a politician, his uneasy relationship with Roosevelt and Churchill during World War II, also the roots of developing a “nationalistic” approach to regional policy after the end of the war. The article also considers the emergence of the Common Agricultural Policy (hereinafter - CAP), one of Charles de Gaulle’s biggest achievements in foreign policy, and the reasons for the Fouchet Plan defeat.

“There is such a situation that Comrade Svoboda is under pressure”. The Soviet leadership and the settlement of relations with Czechoslovakia. May 1969

2019 ◽  
pp. 512-519
Author(s):  
Teymur Dzhalilov ◽  
Nikita Pivovarov
Keyword(s):  
Central Committee ◽  
Secretary General ◽  
Political Agenda ◽  
The Political ◽  
Soviet Government ◽  
Soviet Leadership ◽  
Policy Issues ◽  
The World ◽  
The Common

The published document is a part of the working record of The Secretariat of the CPSU Central Committee on May 5, 1969. The employees of The Common Department of the CPSU Central Committee started writing such working records from the end of 1965. In contrast to the protocols, the working notes include speeches of the secretaries of the Central Committee, that allow to deeper analyze the reactions of the top party leadership, to understand their position regarding the political agenda. The peculiarity of the published document is that the Secretariat of the Central Committee did not deal with the most important foreign policy issues. It was the responsibility of the Politburo. However, it was at a meeting of the Secretariat of the Central Committee when Brezhnev raised the question of inviting G. Husák to Moscow. The latter replaced A. Dubček as the first Secretary of the Communist party of Czechoslovakia in April 1969. As follows from the document, Leonid Brezhnev tried to solve this issue at a meeting of the Politburo, but failed. However, even at the Secretariat of the Central Committee the Leonid Brezhnev’s initiative at the invitation of G. Husák was not supported. The published document reveals to us not only new facets in the mechanisms of decision-making in the CPSU Central Committee, the role of the Secretary General in this process, but also reflects the acute discussions within the Soviet government about the future of the world socialist systems.

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