scholarly journals Differential Expression of Carotenoid Biosynthesis Genes among Different Colored Flesh in Watermelons [Citrullus lanatus (Thunb)]

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 869E-870 ◽  
Author(s):  
Haejeen Bang* ◽  
Sungil Kim ◽  
Daniel Leskovar ◽  
Stephen King
Keyword(s):  
Differential Expression ◽  
Citrullus Lanatus ◽  
Carotenoid Biosynthesis ◽  
Transcriptional Level ◽  
Degenerate Primers ◽  
Genes Encoding ◽  
Yellow Orange ◽  
Rapid Amplification ◽  
Six Genes ◽  
Leader Intron

Carotenoids are plant compounds that serve a variety of essential functions in the plant and have also been found to have several health-promoting activities in humans. Carotenoids found in watermelon (Citrullus lanatus) flesh are responsible for the various colors such as red, yellow and orange. Previous inheritance studies of flesh color revealed that six genes were involved in color determination. The relationship and interaction of these genes suggests that some color-determining genes may be the result of mutations on the structural genes encoding enzymes in the carotenoid biosynthesis pathway. In this study we were able to isolate and sequence six genes encoding enzymes involved in the carotenoid biosynthetic pathway, and determine their expression in different colored watermelon fruit. The cDNA was synthesized from total RNA using RACE (Rapid Amplification of cDNA ends) kit (SMART RACE cDNA Amplification Kit; Clontech, Palo Alto, Calif.). Degenerate primers were designed based on published homologous genes from other species and were used to isolate gene fragments and full-length cDNAs of phytoene synthase, phytoene desaturase, _-carotene desaturase, β-cyclase, β-carotene hydroxylase and zeaxanthin expoxidase. RT-PCR was carried out to examine any differential expression of cloned genes in white, yellow, orange and red-fleshed watermelon. All cloned enzyme-encoding genes were expressed regardless of flesh colors. These results indicate that carotenoid biosynthesis may be regulated at the post-transcriptional level. One interesting feature supports this hypothesis. In case of β-cyclase, a 229-bp leader intron was identified, and an unspliced mRNA with this leader intron existed dominantly in cDNA pool of all samples.

scholarly journals NtbHLH1, a JAF13-like bHLH, interacts with NtMYB6 to enhance proanthocyanidin accumulation in Chinese Narcissus

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yuxin Fan ◽  
Jiayu Peng ◽  
Jiacheng Wu ◽  
Ping Zhou ◽  
Ruijie He ◽  
...  
Keyword(s):  
Flavonoid Biosynthesis ◽  
Transcriptional Level ◽  
Flavonoid Pathway ◽  
Regulation Of Expression ◽  
Over Expression ◽  
Expression Of Genes ◽  
Genes Encoding ◽  
Regulatory Complex ◽  
Positive Regulators ◽  
R2r3 Myb

Abstract Background Flavonoid biosynthesis in plants is primarily regulated at the transcriptional level by transcription factors modulating the expression of genes encoding enzymes in the flavonoid pathway. One of the most studied transcription factor complexes involved in this regulation consists of a MYB, bHLH and WD40. However, in Chinese Narcissus (Narcissus tazetta L. var. chinensis), a popular monocot bulb flower, the regulatory mechanism of flavonoid biosynthesis remains unclear. Results In this work, genes related to the regulatory complex, NtbHLH1 and a R2R3-MYB NtMYB6, were cloned from Chinese Narcissus. Phylogenetic analysis indicated that NtbHLH1 belongs to the JAF13 clade of bHLH IIIf subgroup, while NtMYB6 was highly homologous to positive regulators of proanthocyanidin biosynthesis. Both NtbHLH1 and NtMYB6 have highest expression levels in basal plates of Narcissus, where there is an accumulation of proanthocyanidin. Ectopic over expression of NtbHLH1 in tobacco resulted in an increase in anthocyanin accumulation in flowers, and an up-regulation of expression of the endogenous tobacco bHLH AN1 and flavonoid biosynthesis genes. In contrast, the expression level of LAR gene was significantly increased in NtMYB6-transgenic tobacco. Dual luciferase assays showed that co-infiltration of NtbHLH1 and NtMYB6 significantly activated the promoter of Chinese Narcissus DFR gene. Furthermore, a yeast two-hybrid assay confirmed that NtbHLH1 interacts with NtMYB6. Conclusions Our results suggest that NtbHLH1 may function as a regulatory partner by interacting directly with NtMYB6 to enhance proanthocyanidin accumulation in Chinese Narcissus.

scholarly journals New Strategy for Identification of Novel cry-Type Genes from Bacillus thuringiensis Strains

2005 ◽  
Vol 71 (2) ◽  
pp. 761-765 ◽  
Author(s):  
Corina M. Berón ◽  
Leonardo Curatti ◽  
Graciela L. Salerno
Keyword(s):  
Bacillus Thuringiensis ◽  
Phylogenetic Distance ◽  
Cloning And Sequencing ◽  
Degenerate Primers ◽  
Dna Templates ◽  
Cry Proteins ◽  
New Strategy ◽  
Genes Encoding ◽  
Encoding Protein

ABSTRACT We designed five degenerate primers for detection of novel cry genes from Bacillus thuringiensis strains. An efficient strategy was developed based on a two-step PCR approach with these primers in five pair combinations. In the first step, only one of the primer pairs is used in the PCR, which allows amplification of DNA fragments encoding protein regions that include consensus domains of representative proteins belonging to different Cry groups. A second PCR is performed by using the first-step amplification products as DNA templates and the set of five primer combinations. Cloning and sequencing of the last-step amplicons allow both the identification of known cry genes encoding Cry proteins covering a wide phylogenetic distance and the detection and characterization of cry-related sequences from novel B. thuringiensis isolates.

scholarly journals Identification of Streptococci to Species Level by Sequencing the Gene Encoding the Manganese-Dependent Superoxide Dismutase

1998 ◽  
Vol 36 (1) ◽  
pp. 41-47 ◽  
Author(s):  
Claire Poyart ◽  
Gilles Quesne ◽  
Stephane Coulon ◽  
Patrick Berche ◽  
Patrick Trieu-Cuot
Keyword(s):  
Superoxide Dismutase ◽  
Pcr Assay ◽  
Degenerate Primers ◽  
Gene Encoding ◽  
Genes Encoding ◽  
Type Strains ◽  
Internal Fragment ◽  
Rrna Sequences ◽  
16S Rrna Sequences

We have used a PCR assay based on the use of degenerate primers in order to characterize an internal fragment (sodAint ) representing approximately 85% of the genes encoding the manganese-dependent superoxide dismutase in various streptococcal type strains (S. acidominimus,S. agalactiae, S. alactolyticus, S. anginosus, S. bovis, S. constellatus,S. canis, S. cricetus, S. downei,S. dysgalactiae, S. equi subsp.equi, S. equi subsp. zooepidemicus,S. equinus, S. gordonii, S. iniae,S. intermedius, S. mitis, S. mutans, S. oralis, S. parasanguis,S. pneumoniae, S. porcinus, S. pyogenes, S. salivarius, S. sanguis,S. sobrinus, S. suis, S. thermophilus, and S. vestibularis). Phylogenetic analysis of these sodAint fragments yields an evolutionary tree having a topology similar to that of the tree constructed with the 16S rRNA sequences. We have shown that clinical isolates could be identified by determining the positions of theirsodAint fragments on the phylogenetic tree of the sodAint fragments of the type species. We propose this method for the characterization of strains that cannot be assigned to a species on the basis of their conventional phenotypic reactions.

scholarly journals EPR study of thylakoid membrane dynamics in mutants of the carotenoid biosynthesis pathway of Synechocystis sp. PCC6803.

2012 ◽  
Vol 59 (1) ◽  
Author(s):  
Kinga Kłodawska ◽  
Przemysław Malec ◽  
Mihály Kis ◽  
Zoltán Gombos ◽  
Kazimierz Strzałka
Keyword(s):  
Optimal Growth ◽  
Carotenoid Biosynthesis ◽  
Growth Conditions ◽  
Thylakoid Membranes ◽  
Membrane Dynamics ◽  
Biosynthesis Pathway ◽  
Light Regimes ◽  
Genes Encoding ◽  
Splitting Parameter ◽  
Carotenoid Biosynthesis Pathway

EPR spectroscopy using 5-doxylstearic acid (5-SASL) and 16-doxylstearic acid (16-SASL) spin probes was used to study the fluidity of thylakoid membranes. These were isolated from wild type Synechocystis and from several mutants in genes encoding selected enzymes of the carotenoid biosynthesis pathway and/or acyl-lipid desaturases. Cyanobacteria were cultivated at 25°C and 35°C under different light regimes: photoautotrophically (PAG) and/or in light-activated heterotrophic conditions (LAHG). The relative fluidity of membranes was estimated from EPR spectra based on the empirical outermost splitting parameter in a temperature range from 15°C to 40°C. Our findings demonstrate that in native thylakoid membranes the elimination of xanthophylls decreased fluidity in the inner membrane region under optimal growth conditions (25°C) and increased it under sublethal heat stress (35°C). This indicated that the overall fluidity of native photosynthetic membranes in cyanobacteria may be influenced by the ratio of polar to non-polar carotenoid pools under different environmental conditions.

scholarly journals PhhB, a Pseudomonas aeruginosa Homolog of Mammalian Pterin 4a-Carbinolamine Dehydratase/DCoH, Does Not Regulate Expression of Phenylalanine Hydroxylase at the Transcriptional Level

1999 ◽  
Vol 181 (9) ◽  
pp. 2789-2796 ◽  
Author(s):  
Jian Song ◽  
Tianhui Xia ◽  
Roy A. Jensen
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Phenylalanine Hydroxylase ◽  
Transcriptional Level ◽  
Gene Encoding ◽  
Catalytic Function ◽  
Genes Encoding ◽  
Catalytic Role ◽  
Regulatory Effects

ABSTRACT Pterin 4a-carbinolamine dehydratase is bifunctional in mammals. In addition to playing a catalytic role in pterin recycling in the cytoplasm, it plays a regulatory role in the nucleus, where it acts as a dimerization-cofactor component (called DCoH) for the transcriptional activator HNF-1α. A thus far unique operon in Pseudomonas aeruginosa contains a gene encoding a homolog (PhhB) of the regulatory dehydratase, together with genes encoding phenylalanine hydroxylase (PhhA) and aromatic aminotransferase (PhhC). Using complementation of tyrosine auxotrophy in Escherichia colias a functional test, we have found that the in vivo function of PhhA requires PhhB. Strikingly, mammalian DCoH was an effective substitute for PhhB, and either one was effective in trans. Surprisingly, the required presence of PhhB for complementation did not reflect a critical positive regulatory effect of phhB onphhA expression. Rather, in the absence of PhhB, PhhA was found to be extremely toxic in E. coli, probably due to the nonenzymatic formation of 7-biopterin or a similar derivative. However, bacterial PhhB does appear to exert modest regulatory effects in addition to having a catalytic function. PhhB enhances the level of PhhA two- to threefold, as was demonstrated by gene inactivation ofphhB in P. aeruginosa and by comparison of the levels of expression of PhhA in the presence and absence of PhhB inEscherichia coli. Experiments using constructs having transcriptional and translational fusions with a lacZreporter indicated that PhhB activates PhhA at the posttranscriptional level. Regulation of PhhA and PhhB is semicoordinate; both PhhA and PhhB are induced coordinately in the presence of eitherl-tyrosine or l-phenylalanine, but PhhB exhibits a significant basal level of activity that is lacking for PhhA. Immunoprecipitation and affinity chromatography showed that PhhA and PhhB form a protein-protein complex.

scholarly journals Transcriptome of peanut kernel and shell reveals the mechanism of calcium on peanut pod development

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Sha Yang ◽  
Jianguo Wang ◽  
Zhaohui Tang ◽  
Feng Guo ◽  
Ye Zhang ◽  
...  
Keyword(s):  
Early Stage ◽  
Central Element ◽  
Abnormal Development ◽  
Transcriptional Level ◽  
Peanut Kernel ◽  
Rna Seq ◽  
Embryo Abortion ◽  
Genes Encoding ◽  
Pod Development ◽  
The Relationship

Abstract Calcium is not only a nutrient necessary for plant growth but also a ubiquitous central element of different signaling pathways. Ca2+ deficiency in soil may cause embryo abortion, which can eventually lead to abnormal development of peanut pods during the harvest season. To further study the mechanisms by which Ca2+ affects the shells and kernels of peanuts, transcriptome sequencing was used to explore the genes differentially expressed in shells and kernels during the early stage of peanut pod development between Ca2+ sufficient and deficient treatments. In this study, 38,894 expressed genes were detected. RNA-seq based gene expression profiling showed a large number of genes at the transcriptional level that changed significantly in shells and kernels between the Ca2+ sufficient and deficient treatments, respectively. Genes encoding key proteins involved in Ca2+ signal transduction, hormones, development, ion transport, and nutrition absorption changed significantly. Meanwhile, in the early stage of pod development, calcium first promoted nutrient absorption and development of shells, which has less effect on the formation of seed kernels. These results provide useful information for understanding the relationship between Ca2+ absorption and pod development.

scholarly journals Reprograming of epigenetic mechanisms controlling host insect immunity and development in response to egg-laying by a parasitoid wasp

2020 ◽  
Vol 287 (1928) ◽  
pp. 20200704
Author(s):  
Rabia Özbek ◽  
Krishnendu Mukherjee ◽  
Fevzi Uçkan ◽  
Andreas Vilcinskas
Keyword(s):  
Immune System ◽  
Galleria Mellonella ◽  
Specific Effect ◽  
Parasitoid Wasp ◽  
Egg Laying ◽  
Insect Immunity ◽  
Transcriptional Level ◽  
Epigenetic Mechanisms ◽  
Genes Encoding ◽  
Host Genes

Parasitoids are insects that use other insects as hosts. They sabotage host cellular and humoral defences to promote the survival of their offspring by injecting viruses and venoms along with their eggs. Many pathogens and parasites disrupt host epigenetic mechanisms to overcome immune system defences, and we hypothesized that parasitoids may use the same strategy. We used the ichneumon wasp Pimpla turionellae as a model idiobiont parasitoid to test this hypothesis, with pupae of the greater wax moth Galleria mellonella as the host. We found that parasitoid infestation involves the suppression of host immunity-related effector genes and the modulation of host genes involved in developmental hormone signalling. The transcriptional reprogramming of host genes following the injection of parasitoid eggs was associated with changes in host epigenetic mechanisms. The introduction of parasitoids resulted in a transient decrease in host global DNA methylation and the modulation of acetylation ratios for specific histones. Genes encoding regulators of histone acetylation and deacetylation were mostly downregulated in the parasitized pupae, suggesting that parasitoids can suppress host transcription. We also detected a strong parasitoid-specific effect on host microRNAs regulating gene expression at the post-transcriptional level. Our data therefore support the hypothesis that parasitoids may favour the survival of their offspring by interfering with host epigenetic mechanisms to suppress the immune system and disrupt development.

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