Carotenoid Accumulation and Distinct Transcript Profiling of Structural Genes Involved in Carotenoid Biosynthesis in Celery

2018 ◽  
Vol 36 (4) ◽  
pp. 663-674 ◽  
Author(s):  
Jing-Wen Li ◽  
Jing Ma ◽  
Kai Feng ◽  
Jie-Xia Liu ◽  
Feng Que ◽  
...  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xiuling Li ◽  
Jizheng Fan ◽  
Shuming Luo ◽  
Ling Yin ◽  
Hongying Liao ◽  
...  

Abstract Background Paphiopedilum hirsutissimum is a member of Orchidaceae family that is famous for its ornamental value around the globe, it is vulnerable due to over-exploitation and was listed in Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora, which prevents its trade across borders. Variation in flower color that gives rise to different flower patterns is a major trait contributing to its high ornamental value. However, the molecular mechanism underlying color formation in P. hirsutissimum still remains unexplored. In the present study, we exploited natural variation in petal and labellum color of Paphiopedilum plants and used comparative transcriptome analysis as well as pigment measurements to explore the important genes, metabolites and regulatory pathways linked to flower color variation in P. hirsutissimum. Result We observed that reduced anthocyanin and flavonoid contents along with slightly higher carotenoids are responsible for albino flower phenotype. Comparative transcriptome analysis identified 3287 differentially expressed genes (DEGs) among normal and albino labellum, and 3634 DEGs between normal and albino petals. Two genes encoding for flavanone 3-hydroxylase (F3H) and one gene encoding for chalcone synthase (CHS) were strongly downregulated in albino labellum and petals compared to normal flowers. As both F3H and CHS catalyze essentially important steps in anthocyanin biosynthesis pathway, downregulation of these genes is probably leading to albino flower phenotype via down-accumulation of anthocyanins. However, we observed the downregulation of major carotenoid biosynthesis genes including VDE, NCED and ABA2 which was inconsistent with the increased carotenoid accumulation in albino flowers, suggesting that carotenoid accumulation was probably controlled at post-transcriptional or translational level. In addition, we identified several key transcription factors (MYB73, MYB61, bHLH14, bHLH106, MADS-SOC1, AP2/ERF1, ERF26 and ERF87) that may regulate structural genes involved in flower color formation in P. hirsutissimum. Importantly, over-expression of some of these candidate TFs increased anthocyanin accumulation in tobacco leaves which provided important evidence for the role of these TFs in flower color formation probably via regulating key structural genes of the anthocyanin pathway. Conclusion The genes identified here could be potential targets for breeding P. hirsutissimum with different flower color patterns by manipulating the anthocyanin and carotenoid biosynthesis pathways.


2020 ◽  
Vol 9 (1) ◽  
pp. 71
Author(s):  
Julia Marente ◽  
Javier Avalos ◽  
M. Carmen Limón

Carotenoid biosynthesis is a frequent trait in fungi. In the ascomycete Fusarium fujikuroi, the synthesis of the carboxylic xanthophyll neurosporaxanthin (NX) is stimulated by light. However, the mutants of the carS gene, encoding a protein of the RING finger family, accumulate large NX amounts regardless of illumination, indicating the role of CarS as a negative regulator. To confirm CarS function, we used the Tet-on system to control carS expression in this fungus. The system was first set up with a reporter mluc gene, which showed a positive correlation between the inducer doxycycline and luminescence. Once the system was improved, the carS gene was expressed using Tet-on in the wild strain and in a carS mutant. In both cases, increased carS transcription provoked a downregulation of the structural genes of the pathway and albino phenotypes even under light. Similarly, when the carS gene was constitutively overexpressed under the control of a gpdA promoter, total downregulation of the NX pathway was observed. The results confirmed the role of CarS as a repressor of carotenogenesis in F. fujikuroi and revealed that its expression must be regulated in the wild strain to allow appropriate NX biosynthesis in response to illumination.


2019 ◽  
Vol 9 (5) ◽  
pp. 251-257
Author(s):  
Rashidi Othman ◽  
Norazian Mohd. Hassan   ◽  
Ainaa Eliah Abu Bakar ◽  
Nur Hidayah Noh   ◽  
Nurrulhidayah Ahmad Fadzillah   ◽  
...  

All carotenoids originate from a single, common precursor, phytoene. The colour of carotenoids is determinedby desaturation, isomerization, cyclization, hydroxylation and epoxidation of the 40-carbon phytoene. The conjugated double-bond structure and nature of end ring groups confer on the carotenoids properties such as colour and antioxidant activity. Algae may become major sources of carotenoids but the extent of environmental stress and genetic influences on algae carotenoid biosynthesis are poorly understood. Carotenoid biosynthesis can be influenced by many aspects and is liable to geometric isomerization with the existence of oxygen, light and heat which affect the colour degradation and oxidation. Therefore, in this study carotenoid biogenesis is investigated in cell culture of Chlorella fusca as a potential model system for rapid initiation, and extraction of carotenoids by providing stringent control of genetic, developmental and environmental factors. The value of this experimental system for investigating key factors controlling the carotenoid accumulation is then tested by assessing the effects of environmental variables, such as drought stress, light intensity, nutrient strength and media formulation on carotenoid accumulation. Our findings revealed that the conversion of violaxanthin to lutein is due to irradiance stress condition, nutrient strength as well as drought stress. As a result, manipulation of environmental variables will up-regulate lutein concentration. This reaction will restrict the supply of precursors for ABA biosynthesis and the algae cell culture responds by increasing carotenogenic metabolic flux to compensate for this restriction. In conclusion, selecting the appropriate algae species for the appropriate environmental conditions is not only important for yield production, but also for nutritional value quality of carotenoid.


Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 448 ◽  
Author(s):  
Pengjun Lu ◽  
Ruqian Wang ◽  
Changqing Zhu ◽  
Xiumin Fu ◽  
Shasha Wang ◽  
...  

Plastids are sites for carotenoid biosynthesis and accumulation, but detailed information on fruit plastid development and its relation to carotenoid accumulation remains largely unclear. Here, using Baisha (BS; white-fleshed) and Luoyangqing (LYQ; red-fleshed) loquat (Eriobotrya japonica), a detailed microscopic analysis of plastid development during fruit ripening was carried out. In peel cells, chloroplasts turned into smaller chromoplasts in both cultivars, and the quantity of plastids in LYQ increased by one-half during fruit ripening. The average number of chromoplasts per peel cell in fully ripe fruit was similar between the two cultivars, but LYQ peel cell plastids were 20% larger and had a higher colour density, associated with the presence of larger plastoglobules. In flesh cells, chromoplasts could be observed only in LYQ during the middle and late stages of ripening, and the quantity on a per-cell basis was higher than that in peel cells, but the size of chromoplasts was smaller. It was concluded that chromoplasts are derived from the direct conversion of chloroplasts to chromoplasts in the peel, and from de novo differentiation of proplastids into chromoplasts in flesh. The relationship between plastid development and carotenoid accumulation is discussed.


HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 846E-847 ◽  
Author(s):  
Andrew Schofield* ◽  
Gopinadhan Paliyath

The accumulation of carotenoids such as lycopene and beta-carotene greatly influences the quality of ripe tomato (Lycopersicon esculentum) fruit because cellular levels of these compounds determine the intensity of red color. As well, lycopene has anti-cancer properties and beta-carotene is a Vitamin A precursor. Recent work has demonstrated phytochrome regulation of the carotenoid pathway but the mechanism is not completely understood. This work investigates phytochrome regulation of 1-deoxy-D-xylulose 5-phosphate synthase (DXS) and phytoene synthase (PSY), two key enzymes of carotenogenesis. A simple procedure for the assay of PSY from crude pericarp extracts was developed and mRNA levels of DXS and PSY1 genes were measured by relative RT-PCR. Discs from mature green tomatoes were ripened in total darkness, or in darkness interrupted by brief daily treatments of red light, or red light followed by far red light. After ten days of incubation, lycopene levels of red light-treated discs had reached ≈12 mg/100 g fresh weight; nearly a 50% increase over discs ripened in total darkness. This increase was not observed in discs treated with red light followed by far red light, demonstrating the red/far red reversibility (and thus phytochrome control) of carotenoid accumulation. Similar patterns of phytochrome control are observed for PSY activity but not for DXS and PSY1 transcript levels, suggesting the mechanism of control may be at the level of post-translational modification of PSY. Potential applications of this regulation of carotenoid accumulation will be discussed.


2018 ◽  
Vol 13 (3) ◽  
pp. 1934578X1801300
Author(s):  
Do Manh Cuong ◽  
Jae Kwang Kim ◽  
Jin Jeon ◽  
Tae Jin Kim ◽  
Jong Seok Park ◽  
...  

Carotenoids belong to a large group of secondary metabolites, and have pivotal roles in plants, including photosynthesis and phytohormone synthesis, pigmentation, and membrane stabilization. Additionally, carotenoids are potent antioxidants, and their health benefits are becoming increasingly prominent. In recent years, carotenoids have been studied in many plants. Furthermore, gene expression, as well as carotenoid accumulation in different parts of the bitter melon, has been investigated; however, it has not been studied in bitter melon seedlings. In this study, carotenoid accumulation and transcript levels of McGGPPS1, McGGPPS2, McPSY, McPDS, McZDS, McLCYB, McLCYE1, McLCYE2, McCXHB, and McZEP, involved in carotenoid biosynthesis, were analyzed during seedling development using HPLC and qRT-PCR. The major carotenoids that accumulated in the bitter melon seedlings were lutein and E-β-carotene. The expression of most carotenoid biosynthetic genes increased during seedling development, consistent with the accumulation of violaxanthin, lutein, zeaxanthin, β-cryptoxanthin, 13Z-β-carotene, E-β-carotene, and 9Z-β-carotene in bitter melon seedlings. The results of this study provide a firm basis for comprehending the link between gene expression and carotenoid concentration in bitter melon seedlings.


2008 ◽  
Vol 75 (2) ◽  
pp. 405-413 ◽  
Author(s):  
Roberto Rodríguez-Ortiz ◽  
M. Carmen Limón ◽  
Javier Avalos

ABSTRACT The fungus Fusarium fujikuroi (Gibberella fujikuroi MP-C) produces metabolites of biotechnological interest, such as gibberellins, bikaverins, and carotenoids. Gibberellin and bikaverin productions are induced upon nitrogen exhaustion, while carotenoid accumulation is stimulated by light. We evaluated the effect of nitrogen availability on carotenogenesis in comparison with bikaverin and gibberellin production in the wild type and in carotenoid-overproducing mutants (carS). Nitrogen starvation increased carotenoid accumulation in all strains tested. In carS strains, gibberellin and bikaverin biosynthesis patterns differed from those of the wild type and paralleled the expression of key genes for both pathways, coding for geranylgeranyl pyrophosphate (GGPP) and kaurene synthases for the former and a polyketide synthase for the latter. These results suggest regulatory connections between carotenoid biosynthesis and nitrogen-controlled biosynthetic pathways in this fungus. Expression of gene ggs1, which encodes a second GGPP synthase, was also derepressed in the carS mutants, suggesting the participation of Ggs1 in carotenoid biosynthesis. The carS mutations did not affect genes for earlier steps of the terpenoid pathway, such as fppS or hmgR. Light induced carotenoid biosynthesis in the wild type and carRA and carB levels in the wild-type and carS strains irrespective of nitrogen availability.


Genes ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1122
Author(s):  
Yue Jian ◽  
Chenlu Zhang ◽  
Yating Wang ◽  
Zhiqing Li ◽  
Jing Chen ◽  
...  

Chinese kale (Brassica oleracea var. alboglabra) is rich in carotenoids, and neoxanthin is one of the most important carotenoids in Chinese kale. In this study, the function of the neoxanthin synthase gene (BoaNXS) in Chinese kale was investigated. BoaNXS, which had a 699-bp coding sequence, was cloned from the white flower cultivar of Chinese kale and was expressed in all developmental stages and organs of Chinese kale; its expression was highest in young seeds. The subcellular localization indicated that BoaNXS was localized in the chloroplast. BoaNXS-overexpressed plants were obtained via Agrobacterium-mediated transient overexpression methodology, and the gene overexpression efficiencies ranged from 2.10- to 4.24-fold. The color in the leaves of BoaNXS-overexpressed plants changed from green to yellow-green; the content of total and individual carotenoids, such as neoxanthin, violaxanthin, and lutein, was significantly increased, and the expression levels of most carotenoid biosynthetic genes were notably increased. These findings indicated that BoaNXS is of vital importance in carotenoid biosynthesis in Chinese kale and could be used as a candidate gene for enriching the carotenoid accumulation and color of Chinese kale and other Brassica vegetables.


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