Photoreceptors in the dark: A functional white collar-like complex and other putative light-sensing components encoded by the genome of the subterranean fungus Tuber melanosporum

Light influences a wide range of physiological processes from prokaryotes to mammals. Neurospora crassa represents an important model system used for studying this signal pathway. At molecular levels, the WHITE COLLAR Complex (WCC), a heterodimer formed by WC-1 (the blue light photo-sensor) and WC-2 (the transcriptional activator), is the critical positive regulator of light-dependent gene expression. GATN (N indicates any other nucleotide) repeats are consensus sequences within the promoters of light-dependent genes recognized by the WCC. The distal GATN is also known as C-box since it is involved in the circadian clock. However, we know very little about the role of the proximal GATN, and the molecular mechanism that controls the transcription of light-induced genes during the dark/light transition it is still unclear. Here we showed a first indication that mutagenesis of the proximal GATA sequence within the target promoter of the albino-3 gene or deletion of the WC-1 zinc finger domain led to a rise in expression of light-dependent genes already in the dark, effectively decoupling light stimuli and transcriptional activation. This is the first observation of cis-/trans-acting repressive machinery, which is not consistent with the light-dependent regulatory mechanism observed in the eukaryotic world so far.

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“…Real-time qPCR was performed as previously described [39]. Primers used for the cDNA amplification were the following:…”

Section: Methodsmentioning

confidence: 99%

WC-1 and the Proximal GATA Sequence Mediate a Cis-/Trans-Acting Repressive Regulation of Light-Dependent Gene Transcription in the Dark

Brenna

Talora

2019

IJMS

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“…The values of oscillator strengths and transition dipole moments indicate that the S o → S 1 transition is an allowed transition of 𝜋 → 𝜋 * character. The linear relationship between oscillator strength and transition dipole moment is shown in Fig (12). The change in dipole moment of PPPBB upon excitation was calculated from Lippret-Metaga's relation Equations ( 6) and ( 7) [53][54][55], which are based on the energy difference between the maximum absorption and emission band.…”

Section: 4-calculations Of Molecular Parametersmentioning

confidence: 99%

“…Stilbene derivatives are ideal dyes for investigation of the trans/cis photoisomerization reactions [6,7]. Hamond et al [8] provided a classical study for understanding the behavior of some stilbene derivatives in triplet excited state with the rate of intersystem crossing from singlet excited state to triplet state equals zero [9][10][11][12]. Sometimes, the most accepted mechanism of photoisomerization of stilbene derivatives have been reported as trizonal relaxation process [13][14][15].…”

Section: -Introductionmentioning

confidence: 99%

Structural, DFT calculations and photophysical and photochemical characteristics of 1-((E)-2-phenylethenyl)-2-(4-(2-((E)-2-phenylethenyl) phenoxy) butoxy) benzene (PPPBB)

et al. 2023

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X- ray single crystal structure, spectroscopic and photophysical parameters of the titled compound were studied. The titled compound shows thermal stability prior to melting at 126.17 °C with ΔH value of 109.991 Jg<sup>-1</sup>. Photophysical parameters include singlet electronic absorption, molar absorption coefficient, oscillator strength and dipole moment of electronic transition, fluorescence spectra, excited state lifetime and fluorescence quantum yield for PPPBB in different solvents. PPPBB displays a little change in maximum absorption and emission spectra with solvent polarity, indicating a slight change in dipole moment of dye molecules upon excitation. The dipole moments (Δμ ) difference between the excited and ground state was obtained from Lippert-Mataga method. Ground and electronic excited states geometric optimization was performed using density functional theory (DFT) and time-dependent density functional theory (TD-DFT), complemented with spectral findings. A good agreement between theoretical data and experimental observations was found. The net photochemical quantum yield (ϕ<sub>c</sub>) of PPPBB dye was calculated in various solvents.

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“…Tuber melanosporum and Tuber borchii possess genes encoding canonical WC-1/WC-2 systems sensing BL and genes for phy proteins (Table 2, TS2). In both fungi, BL inhibits mycelial growth, a key feature of symbiosis establishment, while the phytochromes were reported to be non-functional (Table 5) [168,169].…”

Section: Neurospora Crassamentioning

confidence: 99%

A light life together: photosensing in the plant microbiota

Losi

Gärtner

2021

Photochem Photobiol Sci

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Bacteria and fungi of the plant microbiota can be phytopathogens, parasites or symbionts that establish mutually advantageous relationships with plants. They are often rich in photoreceptors for UVA–Visible light, and in many cases, they exhibit light regulation of growth patterns, infectivity or virulence, reproductive traits, and production of pigments and of metabolites. In addition to the light-driven effects, often demonstrated via the generation of photoreceptor gene knock-outs, microbial photoreceptors can exert effects also in the dark. Interestingly, some fungi switch their attitude towards plants in dependence of illumination or dark conditions in as much as they may be symbiotic or pathogenic. This review summarizes the current knowledge about the roles of light and photoreceptors in plant-associated bacteria and fungi aiming at the identification of common traits and general working ideas. Still, reports on light-driven infection of plants are often restricted to the description of macroscopically observable phenomena, whereas detailed information on the molecular level, e.g., protein–protein interaction during signal transduction or induction mechanisms of infectivity/virulence initiation remains sparse. As it becomes apparent from still only few molecular studies, photoreceptors, often from the red- and the blue light sensitive groups interact and mutually modulate their individual effects. The topic is of great relevance, even in economic terms, referring to plant-pathogen or plant-symbionts interactions, considering the increasing usage of artificial illumination in greenhouses, the possible light-regulation of the synthesis of plant-growth stimulating substances or herbicides by certain symbionts, and the biocontrol of pests by selected fungi and bacteria in a sustainable agriculture.

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Photoreceptors in the dark: A functional white collar-like complex and other putative light-sensing components encoded by the genome of the subterranean fungus Tuber melanosporum

Cited by 6 publications

References 60 publications

WC-1 and the Proximal GATA Sequence Mediate a Cis-/Trans-Acting Repressive Regulation of Light-Dependent Gene Transcription in the Dark

WC-1 and the Proximal GATA Sequence Mediate a Cis-/Trans-Acting Repressive Regulation of Light-Dependent Gene Transcription in the Dark

Structural, DFT calculations and photophysical and photochemical characteristics of 1-((E)-2-phenylethenyl)-2-(4-(2-((E)-2-phenylethenyl) phenoxy) butoxy) benzene (PPPBB)

A light life together: photosensing in the plant microbiota

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