scholarly journals The Citrus Transcription Factor CsMADS6 Modulates Carotenoid Metabolism by Directly Regulating Carotenogenic Genes

2018 ◽  
Vol 176 (4) ◽  
pp. 2657-2676 ◽  
Author(s):  
Suwen Lu ◽  
Yin Zhang ◽  
Kaijie Zhu ◽  
Wei Yang ◽  
Junli Ye ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Carotenoid Metabolism ◽  
Carotenogenic Genes

A citrus phosphate starvation response factor CsPHL3 negatively regulates carotenoid metabolism

2021 ◽  
Author(s):  
Suwen Lu ◽  
Junli Ye ◽  
Kaijie Zhu ◽  
Yin Zhang ◽  
Mengwei Zhang ◽  
...  
Keyword(s):  
Anthocyanin Biosynthesis ◽  
Carotenoid Biosynthesis ◽  
Underlying Mechanism ◽  
Response Factor ◽  
Starvation Response ◽  
Abnormal Growth ◽  
Carotenoid Metabolism ◽  
Pi Starvation ◽  
Carotenogenic Genes ◽  
Regulation Mechanisms

Abstract Carotenoids provide precursors for the biosynthesis of strigolactones (SLs), which are a new class of hormones that are essential in phosphate (Pi) signaling during plant development. Carotenoid metabolism is a finely tuned pathway but our understanding of the regulation mechanisms is still limited. In this study, we isolated a protein designated as CsPHL3 from citrus. CsPHL3 belonged to the Pi starvation response factor (PHR)-like subclade and was up-regulated by low Pi. Acting as a nucleus-localized protein with transactivation activity, CsPHL3 bound directly to activate the promoter of a key metabolic gene, lycopene β-cyclase1 (LCYb1). Transgenic analysis revealed that the CsPHL3-overexpressing tomato plants exhibited abnormal growth, like the plants grew under limited Pi conditions. The transgenic lines showed reduced carotenoid contents, elevated expression of LCYb genes but downregulation of other key carotenogenic genes including phytoene synthase (PSY). Moreover, CsPHL3 induced anthocyanin biosynthesis and affected Pi signaling in the transgenic plants. We further demonstrated that the expression of PSY was negatively regulated by CsPHL3 and high Pi. It is concluded that CsPHL3 is a Pi starvation response factor that negatively regulates carotenoid metabolism by modulating the expression of carotenogenic genes. Establishment of the CsPHL3-CsLCYb1 network provides new valuable knowledge of the function and underlying mechanism of PHR transcription factors and expands our understanding of the complex regulation mechanisms of carotenoid biosynthesis.

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

2016 ◽  
Vol 71 (9-10) ◽  
pp. 303-311 ◽  
Author(s):  
Gerhard Sandmann ◽  
Jürgen Mautz ◽  
Jürgen Breitenbach
Keyword(s):  
Transcription Factor ◽  
Redox State ◽  
Photosynthetic Electron Transport ◽  
Carotenoid Biosynthesis ◽  
High Light ◽  
Light Conditions ◽  
Promoter Regions ◽  
Carotenogenic Genes ◽  
Pcc 7120 ◽  
Β Carotene

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.

scholarly journals SlZHD17 is involved in the control of chlorophyll and carotenoid metabolism in tomato fruit

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Yuan Shi ◽  
Xiaoqin Pang ◽  
Wenjing Liu ◽  
Rui Wang ◽  
Deding Su ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Fruit Quality ◽  
Regulatory Network ◽  
Agronomic Traits ◽  
Chlorophyll Biosynthesis ◽  
Tomato Fruit ◽  
Plastid Transformation ◽  
Chlorophyll Degradation ◽  
Myb Transcription Factor ◽  
Carotenoid Metabolism

AbstractChlorophylls and carotenoids are essential and beneficial substances for both plant and human health. Identifying the regulatory network of these pigments is necessary for improving fruit quality. In a previous study, we identified an R2R3-MYB transcription factor, SlMYB72, that plays an important role in chlorophyll and carotenoid metabolism in tomato fruit. Here, we demonstrated that the SlMYB72-interacting protein SlZHD17, which belongs to the zinc-finger homeodomain transcription factor family, also functions in chlorophyll and carotenoid metabolism. Silencing SlZHD17 in tomato improved multiple beneficial agronomic traits, including dwarfism, accelerated flowering, and earlier fruit harvest. More importantly, downregulating SlZHD17 in fruits resulted in larger chloroplasts and a higher chlorophyll content. Dual-luciferase, yeast one-hybrid and electrophoretic mobility shift assays clarified that SlZHD17 regulates the chlorophyll biosynthesis gene SlPOR-B and chloroplast developmental regulator SlTKN2 in a direct manner. Chlorophyll degradation and plastid transformation were also retarded after suppression of SlZHD17 in fruits, which was caused by the inhibition of SlSGR1, a crucial factor in chlorophyll degradation. On the other hand, the expression of the carotenoid biosynthesis genes SlPSY1 and SlZISO was also suppressed and directly regulated by SlZHD17, which induced uneven pigmentation and decreased the lycopene content in fruits with SlZHD17 suppression at the ripe stage. Furthermore, the protein–protein interactions between SlZHD17 and other pigment regulators, including SlARF4, SlBEL11, and SlTAGL1, were also presented. This study provides new insight into the complex pigment regulatory network and provides new options for breeding strategies aiming to improve fruit quality.

A fruit ripening-associated transcription factor CsMADS5 positively regulates carotenoid biosynthesis in citrus

2021 ◽  
Author(s):  
Suwen Lu ◽  
Junli Ye ◽  
Kaijie Zhu ◽  
Yin Zhang ◽  
Mengwei Zhang ◽  
...  
Keyword(s):  
Fruit Ripening ◽  
Regulatory Mechanism ◽  
Carotenoid Biosynthesis ◽  
Carotenoid Metabolism ◽  
Transcriptional Regulatory Mechanism ◽  
Transcriptional Regulatory ◽  
Carotenogenic Genes ◽  
Transient Overexpression ◽  
Biochemical Analyses

Abstract Carotenoids in citrus contribute the quality of the fruit, but the transcriptional regulatory mechanism is still limitedly known. Here, we characterized a citrus FUL-like MADS gene, CsMADS5, that was ripening-inducible and acted as a nucleus-localized trans-activator. Transient overexpression of CsMADS5 in citrus induced fruit coloration and enhanced carotenoid contents. The expression levels of carotenogenic genes including phytoene synthase (PSY), phytoene desaturase (PDS), and lycopene β-cyclase 1 (LCYb1) were significantly increased in the peel of fruits overexpressing CsMADS5. Similar results were observed from stable overexpression of CsMADS5 in tomato fruits and citrus calli, even though the effect of CsMADS5 on the carotenoid metabolism in transgenic citrus calli was limited. Further biochemical analyses demonstrated that CsMADS5 activated the transcription of PSY, PDS, and LCYb1 by directly binding to their promoters. It is concluded that CsMADS5 positively regulates carotenoid biosynthesis in fruits by directly activating the transcription of carotenogenic genes. Moreover, CsMADS5 physically interacted with a positive regulator CsMADS6, indicating that CsMADS5 may form an enhancer complex with CsMADS6 to synergistically promote carotenoid accumulation. These findings expand our understanding of the complex transcriptional regulatory hierarchy for carotenoid biosynthesis during fruit ripening.

scholarly journals Transcriptomic and metabolic analysis uncovers the role of light quality in carotenoid accumulation of grapefruit during ripening

2021 ◽  
Author(s):  
Liulian Huang ◽  
Linping Hu ◽  
Wenbin Kong ◽  
Can Yang ◽  
Wanpeng Xi
Keyword(s):  
Red Light ◽  
Carotenoid Content ◽  
Citrus Fruits ◽  
Carotenoid Metabolism ◽  
Total Carotenoid Content ◽  
Carotenogenic Genes ◽  
Induced Changes ◽  
Role Of Light

Abstract Light, a crucial environmental signal, is involved in the regulation of secondary metabolites. To understand the mechanism by which light influences carotenoid metabolism, grapefruits were bagged with four types of light-transmitting bags that altered the transmission of solar light. We showed that light-transmitting bagging induced changes in carotenoid metabolism during fruit ripening. Compared with natural light, red light (RL)-transmittance treatments significantly increased the total carotenoid content by 142%. Based on weighted gene co-expression network analysis (WGCNA), ‘red’, ‘darkred’, ‘yellow’, ‘brown’ and ‘midnightblue’ modules were remarkably associated with carotenoid metabolism under different light treatment. Transcriptome analysis identified the transcription factors (TFs) bHLH74/91/122, NAC56/78/90/100, MYB/MYB308, WRKY7/55, MADS29/AGL61, ERF043/118 as being involved in the regulation of carotenoid metabolism in response to RL. Under RL treatment, these TFs regulated the accumulation of carotenoids by directly modulating the expression of carotenogenic genes, including PSY, Z-ISO2, ZDS6, LCYB, LCYE, CHYB, CCD1-1/1-3, CCD4-2 and NCED2/3. Based on these results, a network of the regulation of carotenoid metabolism by light in citrus fruits was preliminarily proposed. These results showed that RL treatments have great potential to improve coloration and nutritional quality of citrus fruits.

Transcription factor/DNA interactions visualized by electron spectroscopic imaging

1992 ◽  
Vol 50 (1) ◽  
pp. 450-451
Author(s):  
David P. Bazett-Jones ◽  
Mark L. Brown
Keyword(s):  
Transcription Factor ◽  
Dna Sequences ◽  
Transcription Initiation ◽  
Molecular Mechanisms ◽  
Phosphorus Content ◽  
Spectroscopic Imaging ◽  
Electron Spectroscopic Imaging ◽  
Dna Backbone ◽  
Two Parameters ◽  
High Level

A multisubunit RNA polymerase enzyme is ultimately responsible for transcription initiation and elongation of RNA, but recognition of the proper start site by the enzyme is regulated by general, temporal and gene-specific trans-factors interacting at promoter and enhancer DNA sequences. To understand the molecular mechanisms which precisely regulate the transcription initiation event, it is crucial to elucidate the structure of the transcription factor/DNA complexes involved. Electron spectroscopic imaging (ESI) provides the opportunity to visualize individual DNA molecules. Enhancement of DNA contrast with ESI is accomplished by imaging with electrons that have interacted with inner shell electrons of phosphorus in the DNA backbone. Phosphorus detection at this intermediately high level of resolution (≈lnm) permits selective imaging of the DNA, to determine whether the protein factors compact, bend or wrap the DNA. Simultaneously, mass analysis and phosphorus content can be measured quantitatively, using adjacent DNA or tobacco mosaic virus (TMV) as mass and phosphorus standards. These two parameters provide stoichiometric information relating the ratios of protein:DNA content.

The role of transcription factor Egr‐1 in IL‐1 up‐regulation of tubular CD44 expression

Nephrology ◽  
2000 ◽  
Vol 5 (3) ◽  
pp. A92-A92
Author(s):  
Takazoe K ◽  
Foti R ◽  
Hurst La ◽  
Atkins Rc ◽  
Nikolic‐Paterson DJ.
Keyword(s):  
Transcription Factor ◽  
Cd44 Expression
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