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 Light Microclimate-Driven Changes at Transcriptional Level in Photosynthetic Grape Berry Tissues

Plants ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1769
Author(s):  
Andreia Garrido ◽  
Ric C. H. De Vos ◽  
Artur Conde ◽  
Ana Cunha
Keyword(s):  
Carbohydrate Metabolism ◽  
Developmental Stages ◽  
Relevant Information ◽  
Grape Berry ◽  
Mature Stage ◽  
Transcriptional Level ◽  
Flavonoid Pathway ◽  
Wine Quality ◽  
Expression Of Genes ◽  
Genes Encoding

Viticulture practices that change the light distribution in the grapevine canopy can interfere with several physiological mechanisms, such as grape berry photosynthesis and other metabolic pathways, and consequently impact the berry biochemical composition, which is key to the final wine quality. We previously showed that the photosynthetic activity of exocarp and seed tissues from a white cultivar (Alvarinho) was in fact responsive to the light microclimate in the canopy (low and high light, LL and HL, respectively), and that these different light microclimates also led to distinct metabolite profiles, suggesting a berry tissue-specific interlink between photosynthesis and metabolism. In the present work, we analyzed the transcript levels of key genes in exocarps and seed integuments of berries from the same cultivar collected from HL and LL microclimates at three developmental stages, using real-time qPCR. In exocarp, the expression levels of genes involved in carbohydrate metabolism (VvSuSy1), phenylpropanoid (VvPAL1), stilbenoid (VvSTS1), and flavan-3-ol synthesis (VvDFR, VvLAR2, and VvANR) were highest at the green stage. In seeds, the expression of several genes associated with both phenylpropanoid (VvCHS1 and VvCHS3) and flavan-3-ol synthesis (VvDFR and VvLAR2) showed a peak at the véraison stage, whereas that of RuBisCO was maintained up to the mature stage. Overall, the HL microclimate, compared to that of LL, resulted in a higher expression of genes encoding elements associated with both photosynthesis (VvChlSyn and VvRuBisCO), carbohydrate metabolism (VvSPS1), and photoprotection (carotenoid pathways genes) in both tissues. HL also induced the expression of the VvFLS1 gene, which was translated into a higher activity of the FLS enzyme producing flavonol-type flavonoids, whereas the expression of several other flavonoid pathway genes (e.g., VvCHS3, VvSTS1, VvDFR, and VvLDOX) was reduced, suggesting a specific role of flavonols in photoprotection of berries growing in the HL microclimate. This work suggests a possible link at the transcriptional level between berry photosynthesis and pathways of primary and secondary metabolism, and provides relevant information for improving the management of the light microenvironment at canopy level of the grapes.

scholarly journals Streptomyces roseolus, A Promising Biocontrol Agent Against Aspergillus flavus, the Main Aflatoxin B1 Producer

Toxins ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 442 ◽  
Author(s):  
Isaura Caceres ◽  
Selma Snini ◽  
Olivier Puel ◽  
Florence Mathieu
Keyword(s):  
Aspergillus Flavus ◽  
Aflatoxin B1 ◽  
Biocontrol Agent ◽  
Cyclopiazonic Acid ◽  
Over Expression ◽  
Expression Of Genes ◽  
B1 Gene ◽  
Genes Encoding ◽  
Molecular Mechanism Of Action ◽  
Potential Use

Crop contamination by aflatoxin B1 is a current problem in tropical and subtropical regions. In the future, this contamination risk may be expanded to European countries due to climate change. The development of alternative strategies to prevent mycotoxin contamination that further contribute to the substitution of phytopharmaceutical products are thus needed. For this, a promising method resides in the use of biocontrol agents. Several actinobacteria strains have demonstrated to effectively reduce the aflatoxin B1 concentration. Nevertheless, the molecular mechanism of action by which these biological agents reduce the mycotoxin concentration has not been determined. The aim of the present study was to test the potential use of Streptomyces roseolus as a biocontrol agent against aflatoxin B1 contamination. Co-cultures with Aspergillus flavus were conducted, and the molecular fungal response was investigated through analyzing the q-PCR expression of 65 genes encoding relevant fungal functions. Moreover, kojic and cyclopiazonic acid concentrations, as well as morphological fungal changes were also analyzed. The results demonstrated that reduced concentrations of aflatoxin B1 and kojic acid were respectively correlated with the down-regulation of the aflatoxin B1 gene cluster and kojR gene expression. Moreover, a fungal hypersporulated phenotype and a general over-expression of genes involved in fungal development were observed in the co-culture condition.

scholarly journals The Effect of Light Intensity on the Expression of Leucoanthocyanidin Reductase in Grapevine Calluses and Analysis of Its Promoter Activity

Genes ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 1156
Author(s):  
Jing Cheng ◽  
Keji Yu ◽  
Mingyue Zhang ◽  
Ying Shi ◽  
Changqing Duan ◽  
...  
Keyword(s):  
Light Intensity ◽  
Promoter Activity ◽  
Flavonoid Biosynthesis ◽  
Response Patterns ◽  
Flavonoid Pathway ◽  
Leucoanthocyanidin Reductase ◽  
Genes Encoding ◽  
Intensity Changes ◽  
Different Response ◽  
Effect Of Light

To investigate the effect of light intensity on flavonoid biosynthesis, grapevine calluses were subjected to high light (HL, 250 μmol m−2 s−1) and dark (0 μmol m−2 s−1) in comparison to 125 μmol m−2 s−1 under controlled conditions (NL). The alteration of flavonoid profiles was determined and was integrated with RNA sequencing (RNA-seq)-based transcriptional changes of the flavonoid pathway genes. Results revealed that dark conditions inhibited flavonoid biosynthesis. Increasing light intensity affected flavonoids differently—the concentrations of flavonols and anthocyanins as well as the expressions of corresponding genes were less affected, whereas flavan-3-ol concentrations were predominantly increased, which caused enhanced trans-flavan-3-ol concentrations. Moreover, genes encoding leucoanthocyanidin reductase (LAR) exhibited different response patterns to light intensity changes—VviLAR1 expression increased with an increased light intensity, whereas VviLAR2 expression was insensitive. We further confirmed that the known transcription factors (TFs) involved in regulating flavan-3-ol biosynthesis utilized VviLAR1 as a target gene in grapevine calluses. In addition, VviLAR1 promoter activity was more sensitive to light intensity changes than that of VviLAR2 as determined using a transgenic Arabidopsis leaf system. These results suggested that light intensity had the most prominent effect on trans-flavan-3-ols in grapevine calluses and demonstrated that the two LAR genes had different response patterns to light intensity changes.

Transcriptome Analysis of Listeria monocytogenes Grown on a Ready-to-Eat Meat Matrix

2011 ◽  
Vol 74 (7) ◽  
pp. 1104-1111 ◽  
Author(s):  
DONGRYEOUL BAE ◽  
MICHAEL R. CROWLEY ◽  
CHINLING WANG
Keyword(s):  
Listeria Monocytogenes ◽  
Virulence Factors ◽  
Microarray Data ◽  
Meat Products ◽  
Phospholipid Metabolism ◽  
Transcriptional Level ◽  
Cellular Processes ◽  
Reverse Transcription Pcr ◽  
Expression Of Genes ◽  
Genes Encoding

The contamination of ready-to-eat (RTE) meat products with Listeria monocytogenes is a major concern for the food industry. For a better understanding of the adaptation and survival ability of L. monocytogenes grown on turkey deli meat, the transcriptome of L. monocytogenes strain F2365 was determined with a microarray. Microarray data were validated with a quantitative real-time reverse transcription PCR assay. Based on the microarray data, 39 and 45 genes from L. monocytogenes were transcriptionally upregulated and down-regulated, respectively. The genes regulated at the transcriptional level were mainly involved in energy metabolism, fatty acid and phospholipid metabolism, biosynthesis of proteins, transport and binding proteins, DNA metabolism, cellular processes, and regulatory functions. No significant change was noted for the expression of genes encoding known virulence factors such as sigB, prfA, inlA, inlB, plcA, plcB, and hly. These results suggest that L. monocytogenes grown on RTE deli meat changes its transcription of proteins involved in its metabolic pathways to obtain an energy source or to adapt to environmental change without increasing the expression of virulence factors. The global transcriptome profiles provide a better understanding of the growth or adaptation of L. monocytogenes in RTE meat products.

Peptidergic Regulation of Expression of Genes Encoding Antioxidant and Anti-Inflammatory Proteins

2012 ◽  
Vol 152 (5) ◽  
pp. 615-618 ◽  
Author(s):  
V. Kh. Khavinson ◽  
N. S. Lin’kova ◽  
A. V. Dudkov ◽  
V. O. Polyakova ◽  
I. M. Kvetnoi
Keyword(s):  
Regulation Of Expression ◽  
Expression Of Genes ◽  
Genes Encoding ◽  
Inflammatory Proteins ◽  
Anti Inflammatory

scholarly journals Age-related exacerbation of hematopoietic organ damage induced by systemic hyper-inflammation in senescence-accelerated mice

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tomonori Harada ◽  
Isao Tsuboi ◽  
Hirotsugu Hino ◽  
Miyuki Yuda ◽  
Yoko Hirabayashi ◽  
...  
Keyword(s):  
Stromal Cells ◽  
The Elderly ◽  
Organ Damage ◽  
Hematopoietic Organ ◽  
Aged Mice ◽  
Gm Csf ◽  
Expression Of Genes ◽  
Age Related ◽  
Genes Encoding ◽  
Positive Regulators

AbstractHemophagocytic lymphohistiocytosis (HLH) is a life-threatening systemic hyper-inflammatory disorder. The mortality of HLH is higher in the elderly than in young adults. Senescence-accelerated mice (SAMP1/TA-1) exhibit characteristic accelerated aging after 30 weeks of age, and HLH-like features, including hematopoietic organ damage, are seen after lipopolysaccharide (LPS) treatment. Thus, SAMP1/TA-1 is a useful model of hematological pathophysiology in the elderly with HLH. In this study, dosing of SAMP1/TA-1 mice with LPS revealed that the suppression of myelopoiesis and B-lymphopoiesis was more severe in aged mice than in young mice. The bone marrow (BM) expression of genes encoding positive regulators of myelopoiesis (G-CSF, GM-CSF, and IL-6) and of those encoding negative regulators of B cell lymphopoiesis (TNF-α) increased in both groups, while the expression of genes encoding positive-regulators of B cell lymphopoiesis (IL-7, SDF-1, and SCF) decreased. The expression of the GM-CSF-encoding transcript was lower in aged mice than in young animals. The production of GM-CSF by cultured stromal cells after LPS treatment was also lower in aged mice than in young mice. The accumulation of the TNF-α-encoding transcript and the depletion of the IL-7-encoding transcript were prolonged in aged mice compared to young animals. LPS dosing led to a prolonged increase in the proportion of BM M1 macrophages in aged mice compared to young animals. The expression of the gene encoding p16INK4a and the proportion of β-galactosidase- and phosphorylated ribosomal protein S6-positive cells were increased in cultured stromal cells from aged mice compared to those from young animals, while the proportion of Ki67-positive cells was decreased in stromal cells from aged mice. Thus, age-related deterioration of stromal cells probably causes the suppression of hematopoiesis in aged mice. This age-related latent organ dysfunction may be exacerbated in elderly people with HLH, resulting in poor prognosis.

scholarly journals NtMYB3, an R2R3-MYB from Narcissus, Regulates Flavonoid Biosynthesis

2019 ◽  
Vol 20 (21) ◽  
pp. 5456 ◽  
Author(s):  
Muhammad Anwar ◽  
Weijun Yu ◽  
Hong Yao ◽  
Ping Zhou ◽  
Andrew C. Allan ◽  
...  
Keyword(s):  
Transgenic Tobacco ◽  
Flavonoid Biosynthesis ◽  
Pcr Analysis ◽  
Wild Type ◽  
Narcissus Tazetta ◽  
Over Expression ◽  
Qrt Pcr ◽  
Red Color ◽  
R2r3 Myb ◽  
R2r3 Myb Transcription Factors

R2R3-MYB transcription factors play important roles in the regulation of plant flavonoid metabolites. In the current study, NtMYB3, a novel R2R3-MYB transcriptional factor isolated from Chinese narcissus (Narcissus tazetta L. var. chinensis), was functionally characterized. Phylogenetic analysis indicated that NtMYB3 belongs to the AtMYB4-like clade, which includes repressor MYBs involved in the regulation of flavonoid biosynthesis. Transient assays showed that NtMYB3 significantly reduced red pigmentation induced by the potato anthocyanin activator StMYB-AN1 in agro-infiltrated leaves of tobacco. Over-expression of NtMYB3 decreased the red color of transgenic tobacco flowers, with qRT-PCR analysis showing that NtMYB3 repressed the expression levels of genes involved in anthocyanin and flavonol biosynthesis. However, the proanthocyanin content in flowers of transgenic tobacco increased as compared to wild type. NtMYB3 showed expression in all examined narcissus tissues; the expression level in basal plates of the bulb was highest. A 968 bp promoter fragment of narcissus FLS (NtFLS) was cloned, and transient expression and dual luciferase assays showed NtMYB3 repressed the promoter activity. These results reveal that NtMYB3 is involved in the regulation of flavonoid biosynthesis in narcissus by repressing the biosynthesis of flavonols, and this leads to proanthocyanin accumulation in the basal plate of narcissus.

scholarly journals Global gene expression and secondary metabolite changes in Arabidopsis thaliana ABI4 over-expression lines

Botany ◽  
2016 ◽  
Vol 94 (8) ◽  
pp. 615-634 ◽  
Author(s):  
Bianyun Yu ◽  
Margaret Y. Gruber ◽  
Shu Wei ◽  
Rong Zhou ◽  
Dwayne Hegedus ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Secondary Metabolite ◽  
Plant Development ◽  
Global Gene Expression ◽  
Comprehensive Overview ◽  
Altered Expression ◽  
Transcript Levels ◽  
Over Expression ◽  
Expression Of Genes ◽  
Genes Encoding

Despite numerous studies on ABI4, its role in plant secondary metabolism has not been fully investigated. Here, we used metabolite profiling together with transcriptome analysis to demonstrate that ABI4 transcript levels regulate a host of secondary metabolite pathways and growth modalities in ABI4 over-expression (ABI4_OE) lines of Arabidopsis thaliana. This strategy provided a unique and comprehensive overview of the regulation of metabolic shifts in response to ABI4 transcription. We show that enhancement of ABI4 transcript levels changed seed proanthocyanidin (PA), flavonoid, and carotenoid levels in ABI4_OE seeds and 30-day-old shoots, as well as the expression of genes encoding enzymes involved in the production of these and other secondary metabolites in ABI4_OE shoots. In seeds, PA accumulated in very large uneven patches, which was dramatically different from the even distribution of PA in wild-type seeds. Shoots of ABI4_OE lines also exhibited altered expression of a range of genes involved in several aspects of plant development, including hormone and cell-wall synthesis. Alteration of such disparate secondary metabolite pathways, along with hormone and developmental pathways, suggests that ABI4 is a master regulator integrating these compounds with plant development.

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