Control of light-dependent keto carotenoid biosynthesis in Nostoc 7120 by the transcription factor NtcA

Abstract In Nostoc PCC 7120, two different ketolases, CrtW and CrtO are involved in the formation of keto carotenoids from β-carotene. In contrast to other cyanobacteria, CrtW catalyzes the formation of monoketo echinenone whereas CrtO is the only enzyme for the synthesis of diketo canthaxanthin. This is the major photo protective carotenoid in this cyanobacterium. Under high-light conditions, basic canthaxanthin formation was transcriptionally up-regulated. Upon transfer to high light, the transcript levels of all investigated carotenogenic genes including those coding for phytoene synthase, phytoene desaturase and both ketolases were increased. These transcription changes proceeded via binding of the transcription factor NtcA to the promoter regions of the carotenogenic genes. The binding was absolutely dependent on the presence of reductants and oxo-glutarate. Light-stimulated transcript formation was inhibited by DCMU. Therefore, photosynthetic electron transport is proposed as the sensor for high-light and a changing redox state as a signal for NtcA binding.

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Exposure of high-light-grown cultures of Chlorella vulgaris to darkness inhibits the relaxation of excitation pressure: uncoupling of the redox state of the photosynthetic electron transport chain and phenotypic plasticity

Botany ◽

10.1139/cjb-2017-0066 ◽

2017 ◽

Vol 95 (12) ◽

pp. 1125-1140 ◽

Cited By ~ 1

Author(s):

Lauren Hollis ◽

Norman P.A. Hüner

Keyword(s):

Electron Transport ◽

Chlorella Vulgaris ◽

Electron Transport Chain ◽

Redox State ◽

Light Harvesting ◽

Photosynthetic Electron Transport ◽

High Light ◽

Photon Flux ◽

Photosynthetic Electron Transport Chain ◽

Transport Chain

Chlorella vulgaris acclimated to high light (HL) conditions exhibited a pale-green phenotype characterized by reduced chlorophyll and light harvesting polypeptide abundance compared with the dark green phenotype of the control, low-light-grown (LL) cultures. We hypothesized that if chloroplast redox status was the sole regulator of phenotype, exposure to darkness should cause reversion of the HL to LL phenotype. Surprisingly, HL cells transferred to darkness or dim light failed to green. Thus, phenotypic reversion is light-dependent with an optimal photon flux density (PFD) of 110 μmol photons·m−2·s−1. HL cells shifted to this PFD exhibited increased chlorophyll and light harvesting polypeptide abundance, which were inhibited by 2,5-dibromo-3-methyl-6-isopropyl-benzoquinone but not by 3-(3′,4′-dichlorophenyl)-1,1-dimethylurea. We conclude that photoacclimation of HL-grown cells to LL is governed by the redox state of the intersystem photosynthetic electron transport chain (PETC) at this PFD. At lower light levels, cells maintained the HL phenotype, despite an oxidized status of the PETC. Because 110 μmol photons·m−2·s−1 was the optimal PFD for protochlorophyllide oxidoreductase accumulation, we suggest that stabilization of light-harvesting polypeptides by chlorophyll binding may also govern photoacclimation in C. vulgaris. The possible role of the metabolic balance between respiration and photosynthesis is also discussed.

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Substrate Specificities and Availability of Fucosyltransferase and β-Carotene Hydroxylase for Myxol 2′-Fucoside Synthesis in Anabaena sp. Strain PCC 7120 Compared with Synechocystis sp. Strain PCC 6803

Journal of Bacteriology ◽

10.1128/jb.01881-07 ◽

2008 ◽

Vol 190 (20) ◽

pp. 6726-6733 ◽

Cited By ~ 23

Author(s):

Mari Mochimaru ◽

Hajime Masukawa ◽

Takashi Maoka ◽

Hatem E. Mohamed ◽

Wim F. J. Vermaas ◽

...

Keyword(s):

High Performance ◽

Carotenoid Biosynthesis ◽

Biosynthetic Pathways ◽

Wild Type ◽

Substrate Specificities ◽

Field Desorption Mass Spectrometry ◽

Anabaena Sp ◽

Pcc 7120 ◽

Β Carotene ◽

Pcc 6803

ABSTRACT To elucidate the biosynthetic pathways of carotenoids, especially myxol 2′-glycosides, in cyanobacteria, Anabaena sp. strain PCC 7120 (also known as Nostoc sp. strain PCC 7120) and Synechocystis sp. strain PCC 6803 deletion mutants lacking selected proposed carotenoid biosynthesis enzymes and GDP-fucose synthase (WcaG), which is required for myxol 2′-fucoside production, were analyzed. The carotenoids in these mutants were identified using high-performance liquid chromatography, field desorption mass spectrometry, and 1H nuclear magnetic resonance. The wcaG (all4826) deletion mutant of Anabaena sp. strain PCC 7120 produced myxol 2′-rhamnoside and 4-ketomyxol 2′-rhamnoside as polar carotenoids instead of the myxol 2′-fucoside and 4-ketomyxol 2′-fucoside produced by the wild type. Deletion of the corresponding gene in Synechocystis sp. strain PCC 6803 (sll1213; 79% amino acid sequence identity with the Anabaena sp. strain PCC 7120 gene product) produced free myxol instead of the myxol 2′-dimethyl-fucoside produced by the wild type. Free myxol might correspond to the unknown component observed previously in the same mutant (H. E. Mohamed, A. M. L. van de Meene, R. W. Roberson, and W. F. J. Vermaas, J. Bacteriol. 187:6883-6892, 2005). These results indicate that in Anabaena sp. strain PCC 7120, but not in Synechocystis sp. strain PCC 6803, rhamnose can be substituted for fucose in myxol glycoside. The β-carotene hydroxylase orthologue (CrtR, Alr4009) of Anabaena sp. strain PCC 7120 catalyzed the transformation of deoxymyxol and deoxymyxol 2′-fucoside to myxol and myxol 2′-fucoside, respectively, but not the β-carotene-to-zeaxanthin reaction, whereas CrtR from Synechocystis sp. strain PCC 6803 catalyzed both reactions. Thus, the substrate specificities or substrate availabilities of both fucosyltransferase and CrtR were different in these species. The biosynthetic pathways of carotenoids in Anabaena sp. strain PCC 7120 are discussed.

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The PedR transcriptional regulator interacts with thioredoxin to connect photosynthesis with gene expression in cyanobacteria

Biochemical Journal ◽

10.1042/bj20100789 ◽

2010 ◽

Vol 431 (1) ◽

pp. 135-140 ◽

Cited By ~ 26

Author(s):

Mayumi Horiuchi ◽

Kinu Nakamura ◽

Kouji Kojima ◽

Yoshitaka Nishiyama ◽

Wakako Hatakeyama ◽

...

Keyword(s):

Electron Transport ◽

Conformational Change ◽

Photosynthetic Electron Transport ◽

Transcript Level ◽

High Light ◽

Light Conditions ◽

Transport Chain ◽

Acclimation Response ◽

Vitro Analysis

The redox state of the photosynthetic electron transport chain acts as a critical sensing mechanism by regulating the transcription of key genes involved in the acclimation response to a change in the environment. In the present study we show that the small LuxR-type regulator PedR interacts with Trx (thioredoxin) to achieve photosynthetic electron-transport-dependent transcriptional regulation in the cyanobacterium Synechocystis sp. PCC 6803. TrxM, an isoform of Trx, was isolated as an interacting factor of PedR by pull-down assays. In vitro analysis revealed that the intermolecular disulfide bond formed between Cys80 residues of the PedR homodimer was reduced by both TrxM and TrxX. It has been shown previously that, although PedR is active under low-light conditions, it becomes transiently inactivated following a shift to high-light conditions, with a concomitant conformational change [Nakamura and Hihara (2006) J. Biol. Chem. 281, 36758–36766]. In the present study, we found that the conformational change of PedR and the change in the transcript level of its target gene were minimal when mutants of Synechocystis that lack ferredoxin–Trx reductase or NADPH–Trx reductase were exposed to high levels of light. These results indicate that the reduction of PedR by Trx causes transient inactivation of PedR upon the shift of cyanobacterial cells to high-light conditions.

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BBX16 mediates the repression of seedling photomorphogenesis downstream of the GUN1-GLK1 module during retrograde signaling

10.1101/2021.11.08.467520 ◽

2021 ◽

Author(s):

Nil Veciana ◽

Guiomar Martin ◽

Pablo Leivar ◽

Elena Monte

Keyword(s):

Transcription Factor ◽

Seedling Development ◽

Transcriptional Network ◽

High Light ◽

Nuclear Genes ◽

Retrograde Signaling ◽

Light Conditions ◽

Bifurcation Mechanism ◽

Branching Point ◽

Direct Target

Plastid-to-nucleus retrograde signals (RS) initiated by dysfunctional chloroplasts impact photomorphogenic development. We previously showed that the transcription factor GLK1 acts downstream of the RS-regulator GUN1 in photodamaging conditions to regulate not only the well-established expression of photosynthesis-associated nuclear genes (PhANGs) but also to regulate seedling morphogenesis. Specifically, the GUN1/GLK1 module inhibits the light-induced PIF-repressed transcriptional network to suppress cotyledon development when chloroplast integrity is compromised, modulating the area exposed to potentially damaging high light. However, how the GUN1/GLK1 module inhibits photomorphogenesis upon chloroplast damage remained undefined. Here, we report the identification of BBX16 as a novel direct target of GLK1. BBX16 is induced and promotes photomorphogenesis in moderate light and it is repressed via GUN1/GLK1 after chloroplast damage. Additionally, we show that BBX16 represents a regulatory branching point downstream of GUN1/GLK1 in the regulation of PhANG expression and seedling development upon RS activation. The gun1 phenotype in lincomycin and the gun1-like phenotype of GLK1OX are markedly suppressed in gun1bbx16 and GLK1OXbbx16. This study identifies BBX16 as the first member of the BBX family involved in RS, and defines a molecular bifurcation mechanism operated by GLK1/BBX16 to optimize seedling deetiolation, and to ensure photoprotection in unfavorable light conditions.

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An apple (Malus domestica) AP2/ERF transcription factor modulates carotenoid accumulation

Horticulture Research ◽

10.1038/s41438-021-00694-w ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Qingyuan Dang ◽

Haiyun Sha ◽

Jiyun Nie ◽

Yongzhang Wang ◽

Yongbing Yuan ◽

...

Keyword(s):

Transcription Factor ◽

Malus Domestica ◽

Carotenoid Biosynthesis ◽

Carotenoid Content ◽

Ethylene Response Factor ◽

Biosynthesis Pathway ◽

Carotenoid Accumulation ◽

Carotenoid Biosynthesis Pathway ◽

Β Carotene ◽

Erf Transcription Factor

AbstractColor is an important trait for horticultural crops. Carotenoids are one of the main pigments for coloration and have important implications for photosynthesis in plants and benefits for human health. Here, we identified an APETALA2 (AP2)/ETHYLENE RESPONSE FACTOR (ERF) transcription factor named MdAP2-34 in apple (Malus domestica Borkh.). MdAP2-34 expression exhibited a close correlation with carotenoid content in ‘Benin Shogun’ and ‘Yanfu 3’ fruit flesh. MdAP2-34 promotes carotenoid accumulation in MdAP2-34-OVX transgenic apple calli and fruits by participating in the carotenoid biosynthesis pathway. The major carotenoid contents of phytoene and β-carotene were much higher in overexpressing MdAP2-34 transgenic calli and fruit skin, yet the predominant compound of lutein showed no obvious difference, indicating that MdAP2-34 regulates phytoene and β-carotene accumulation but not lutein. MdPSY2-1 (phytoene synthase 2) is a major gene in the carotenoid biosynthesis pathway in apple fruit, and the MdPSY2-1 gene is directly bound and transcriptionally activated by MdAP2-34. In addition, overexpressing MdPSY2-1 in apple calli mainly increases phytoene and total carotenoid contents. Our findings will advance and extend our understanding of the complex molecular mechanisms of carotenoid biosynthesis in apple, and this research is valuable for accelerating the apple breeding process.

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Light Absorption and Partitioning in Response to Nitrogen in Apple Leaves

HortScience ◽

10.21273/hortsci.33.3.541a ◽

1998 ◽

Vol 33 (3) ◽

pp. 541a-541

Author(s):

Lailiang Cheng ◽

Leslie H. Fuchigami ◽

Patrick J. Breen

Keyword(s):

High Light ◽

Thermal Dissipation ◽

Photochemical Quenching ◽

Light Conditions ◽

Psii Efficiency ◽

Fluorescence Measurements ◽

Free Radical Formation ◽

Highly Correlated ◽

Non Photochemical Quenching ◽

Leaf N

Bench-grafted Fuji/M26 apple trees were fertigated with different concentrations of nitrogen by using a modified Hoagland solution for 6 weeks, resulting in a range of leaf N from 1.0 to 4.3 g·m–2. Over this range, leaf absorptance increased curvilinearly from 75% to 92.5%. Under high light conditions (1500 (mol·m–2·s–1), the amount of absorbed light in excess of that required to saturate CO2 assimilation decreased with increasing leaf N. Chlorophyll fluorescence measurements revealed that the maximum photosystem II (PSII) efficiency of dark-adapted leaves was relatively constant over the leaf N range except for a slight drop at the lower end. As leaf N increased, non-photochemical quenching under high light declined and there was a corresponding increase in the efficiency with which the absorbed photons were delivered to open PSII centers. Photochemical quenching coefficient decreased significantly at the lower end of the leaf N range. Actual PSII efficiency increased curvilinearly with increasing leaf N, and was highly correlated with light-saturated CO2 assimilation. The fraction of absorbed light potentially used for free radical formation was estimated to be about 10% regardless of the leaf N status. It was concluded that increased thermal dissipation protected leaves from photo-oxidation as leaf N declined.

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The cyanobacteriumAnabaenasp. PCC 7120 has two distinct β-carotene ketolases: CrtO for echinenone and CrtW for ketomyxol synthesis

FEBS Letters ◽

10.1016/j.febslet.2005.09.081 ◽

2005 ◽

Vol 579 (27) ◽

pp. 6111-6114 ◽

Cited By ~ 36

Author(s):

Mari Mochimaru ◽

Hajime Masukawa ◽

Shinichi Takaichi

Keyword(s):

Pcc 7120 ◽

Β Carotene

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The Role of Selected Wavelengths of Light in the Activity of Photosystem II in Gloeobacter violaceus

International Journal of Molecular Sciences ◽

10.3390/ijms22084021 ◽

2021 ◽

Vol 22 (8) ◽

pp. 4021

Author(s):

Monika Kula-Maximenko ◽

Kamil Jan Zieliński ◽

Ireneusz Ślesak

Keyword(s):

Photosystem Ii ◽

Spectral Composition ◽

Photosynthetic Electron Transport ◽

Metabolic Energy ◽

Light Conditions ◽

Gloeobacter Violaceus ◽

Transport Chain ◽

Cyanobacterial Culture ◽

Photosynthetic Antennas

Gloeobacter violaceus is a cyanobacteria species with a lack of thylakoids, while photosynthetic antennas, i.e., phycobilisomes (PBSs), photosystem II (PSII), and I (PSI), are located in the cytoplasmic membrane. We verified the hypothesis that blue–red (BR) light supplemented with a far-red (FR), ultraviolet A (UVA), and green (G) light can affect the photosynthetic electron transport chain in PSII and explain the differences in the growth of the G. violaceus culture. The cyanobacteria were cultured under different light conditions. The largest increase in G. violaceus biomass was observed only under BR + FR and BR + G light. Moreover, the shape of the G. violaceus cells was modified by the spectrum with the addition of G light. Furthermore, it was found that both the spectral composition of light and age of the cyanobacterial culture affect the different content of phycobiliproteins in the photosynthetic antennas (PBS). Most likely, in cells grown under light conditions with the addition of FR and G light, the average antenna size increased due to the inactivation of some reaction centers in PSII. Moreover, the role of PSI and gloeorhodopsin as supplementary sources of metabolic energy in the G. violaceus growth is discussed.

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Changes in the Stoichiometry of Photosystem II Components as an Adaptive Response to High-Light and Low-Light Conditions during Growth

Zeitschrift für Naturforschung C ◽

10.1515/znc-1986-5-618 ◽

1986 ◽

Vol 41 (5-6) ◽

pp. 597-603 ◽

Cited By ~ 33

Author(s):

Aloysius Wild ◽

Matthias Höpfner ◽

Wolfgang Rühle ◽

Michael Richter

Keyword(s):

Photosystem Ii ◽

Functional Organization ◽

Photosynthetic Apparatus ◽

High Light ◽

Molar Ratio ◽

Light Conditions ◽

Low Light ◽

Pigment System ◽

Transport Chain ◽

The One

The effect of different growth light intensities (60 W·m-2, 6 W·m-2) on the performance of the photosynthetic apparatus of mustard plants (Sinapis alba L.) was studied. A distinct decrease in photosystem II content per chlorophyll under low-light conditions compared to high-light conditions was found. For P-680 as well as for Oᴀ and Oв protein the molar ratio between high-light and low-light plants was 1.4 whereas the respective concentrations per chlorophyll showed some variations for P-680 and Oᴀ on the one and Oв protein on the other hand.In addition to the study of photosystem II components, the concentrations of PQ, Cyt f, and P-700 were measured. The light regime during growth had no effect on the amount of P-700 per chlorophyll but there were large differences with respect to PQ and Cyt f. The molar ratio for Cyt f and PQ between high- and low-light leaves was 2.2 and 1.9, respectively.Two models are proposed, showing the functional organization of the pigment system and the electron transport chain in thylakoids of high-light and low-light leaves of mustard plants.

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