scholarly journals Ethylene Acts as a Negative Regulator of the Stem-Bending Mechanism of Different Cut Snapdragon Cultivars

2021 ◽  
Vol 12 ◽  
Author(s):  
Aung Htay Naing ◽  
May Thu Soe ◽  
Jeong Hyun Yeum ◽  
Chang Kil Kim
Keyword(s):  
Lignin Content ◽  
Shoot Elongation ◽  
Negative Regulator ◽  
Silver Thiosulfate ◽  
Expression Of Genes ◽  
Stem Bending ◽  
Ethylene Action ◽  
Commercially Important ◽  
Bending Mechanism ◽  
Stem Curvature

This study investigated whether ethylene is involved in the stem-bending mechanism of three different snapdragon cultivars ‘Asrit Red’, ‘Asrit Yellow’, and ‘Merryred Pink’, by treating their cut stems with an ethylene-releasing compound (ethephon), an ethylene-action inhibitor [silver thiosulfate (STS)], and distilled water (as the control). Ethephon completely prevented stem bending in all cultivars, whereas STS exhibited a higher bending rate compared with the control. The bending rates were influenced by several factors, such as the degree of stem curvature, relative shoot elongation, ethylene production, and lignin content, indicating their involvement in the stem-bending mechanism of the cultivars. The analysis of the expression of genes involved in the ethylene and lignin biosynthetic pathways also supported the importance of lignin and ethylene in the stem-bending mechanism. Taken together, as ethephon completely prevented stem bending of the three snapdragon cultivars, this study suggested that ethylene acts as a negative regulator of the stem-bending mechanism of snapdragon cultivars, and the information will be valuable for the prevention of stem bending in other commercially important ornamental flowers.

scholarly journals Characterizing the effects of different chemicals on stem bending of cut snapdragon flower

Plant Methods ◽  
2022 ◽  
Vol 18 (1) ◽  
Author(s):  
May Thu Soe ◽  
Aung Htay Naing ◽  
Soo Rin Kim ◽  
Chang Kil Kim
Keyword(s):  
Plant Growth ◽  
Lignin Content ◽  
Shoot Elongation ◽  
Nitric Oxide Donor ◽  
Vase Life ◽  
Cut Flowers ◽  
Stem Bending ◽  
Ethylene Action ◽  
Stem Curvature

Abstract Background This study investigated the effects of ethylene release compounds (ethephon), ethylene-action inhibitors (silver thiosulfate: STS), and nitric oxide donor (sodium nitroprusside: SNP) on stem bending of snapdragon flowers. Moreover, the effects of plant growth supplements [6-benzyladenine (BA), gibberellic acid 3 (GA3), and calcium chloride (CaCl2)] on the stem bending were also extensively investigated. Results Ethephon completely prevented stem bending until 9 days after treatment (9 DAT). STS exhibited the highest bending rate, while SNP did not significantly affect the bending compared to the controls. The bending results were associated with the results of stem curvature, relative shoot elongation, ethylene production, and lignin content, that are involved in the stem bending mechanism. This was proven by the expression analysis of genes involved in ethylene and lignin biosynthetic pathways. The addition of plant growth supplements slightly or significantly delayed stem bending in the treatments (control, SNP, and STS) and significantly reduced petal senescence in ethephon at 9 DAT. Conclusion These results show the preventive role of ethephon in the stem bending of cut snapdragon. Moreover, the combination of ethephon with supplements also provided information that could guide the development of strategies to delay stem bending in other cut flowers that undergo serious bending during a short vase life.

scholarly journals Sexual Differentiation Is Coordinately Regulated by Cryptococcus neoformans CRK1 and GAT1

Genes ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 669
Author(s):  
Kuang-Hung Liu ◽  
Wei-Chiang Shen
Keyword(s):  
Cryptococcus Neoformans ◽  
Sexual Differentiation ◽  
Regulatory Networks ◽  
Genetic Interaction ◽  
Negative Regulator ◽  
Wild Type ◽  
Basidiomycetous Fungus ◽  
Regulatory Circuit ◽  
Expression Of Genes ◽  
In The Wild

The heterothallic basidiomycetous fungus Cryptococcus neoformans has two mating types, MATa and MATα. Morphological progression of bisexual reproduction in C. neoformans is as follows: yeast to hyphal transition, filament extension, basidium formation, meiosis, and sporulation. C. neoformans Cdk-related kinase 1 (CRK1) is a negative regulator of bisexual mating. In this study, we characterized the morphological features of mating structures in the crk1 mutant and determined the genetic interaction of CRK1 in the regulatory networks of sexual differentiation. In the bilateral crk1 mutant cross, despite shorter length of filaments than in the wild-type cross, dikaryotic filaments and other structures still remained intact during bisexual mating, but the timing of basidium formation was approximately 18 h earlier than in the cross between wild type strains. Furthermore, gene expression analyses revealed that CRK1 modulated the expression of genes involved in the progression of hyphal elongation, basidium formation, karyogamy and meiosis. Phenotypic results showed that, although deletion of C. neoformans CRK1 gene increased the efficiency of bisexual mating, filamentation in the crk1 mutant was blocked by MAT2 or ZNF2 mutation. A bioinformatics survey predicted the C. neoformans GATA transcriptional factor Gat1 as a potential substrate of Crk1 kinase. Our genetic and phenotypic findings revealed that C. neoformans GAT1 and CRK1 formed a regulatory circuit to negatively regulate MAT2 to control filamentation progression and transition during bisexual mating.

scholarly journals The circadian protein BMAL1 in myeloid cells is a negative regulator of allergic asthma

2017 ◽  
Vol 312 (6) ◽  
pp. L855-L860 ◽  
Author(s):  
Zbigniew Zasłona ◽  
Sarah Case ◽  
James O. Early ◽  
Stephen J. Lalor ◽  
Rachel M. McLoughlin ◽  
...  
Keyword(s):  
Allergic Asthma ◽  
Molecular Clock ◽  
Circadian Variation ◽  
Myeloid Cells ◽  
Mannose Receptor ◽  
Receptor Expression ◽  
Negative Regulator ◽  
Expression Of Genes ◽  
Crucial Component

Our body clock drives rhythms in the expression of genes that have a 24-h periodicity. The transcription factor BMAL1 is a crucial component of the molecular clock. A number of physiological processes, including immune function, are modulated by the circadian clock. Asthma, a disease with very strong clinical evidence demonstrating regulation by circadian variation, is of particular relevance to circadian control of immunity. Airway hypersensitivity and asthma attacks are more common at night in humans. The molecular basis for this is unknown, and there is no model of asthma in animals with genetic distortion of the molecular clock. We used mice lacking BMAL1 in myeloid cells (BMAL1-LysM−/−) to determine the role of BMAL1 in allergic asthma. Using the ovalbumin model of allergic asthma, we demonstrated markedly increased asthma features, such as increased lung inflammation, demonstrated by drastically higher numbers of eosinophils and increased IL-5 levels in the lung and serum, in BMAL1-LysM−/− mice. In vitro studies demonstrated increased proinflammatory chemokine and mannose receptor expression in IL-4- as well as LPS-treated macrophages from BMAL1-LysM−/− mice compared with wild-type controls. This suggests that Bmal1 is a potent negative regulator in myeloid cells in the context of allergic asthma. Our findings might explain the increase in asthma incidents during the night, when BMAL1 expression is low.

scholarly journals Evaluation of the effects of sdiA, a luxR homologue, on adherence and motility of Escherichia coli O157 : H7

Microbiology ◽  
2010 ◽  
Vol 156 (5) ◽  
pp. 1303-1312 ◽  
Author(s):  
Vijay K. Sharma ◽  
Shawn M. D. Bearson ◽  
Bradley L. Bearson
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cells ◽  
Mutant Strain ◽  
Regulatory Networks ◽  
Double Mutant ◽  
Negative Regulator ◽  
Wild Type ◽  
Reverse Transcription Pcr ◽  
Expression Of Genes ◽  
Genes Encoding

Quorum-sensing (QS) signalling pathways are important regulatory networks for controlling the expression of genes promoting adherence of enterohaemorrhagic Escherichia coli (EHEC) O157 : H7 to epithelial cells. A recent study has shown that EHEC O157 : H7 encodes a luxR homologue, called sdiA, which upon overexpression reduces the expression of genes encoding flagellar and locus of enterocyte effacement (LEE) proteins, thus negatively impacting on the motility and intimate adherence phenotypes, respectively. Here, we show that the deletion of sdiA from EHEC O157 : H7 strain 86-24, and from a hha (a negative regulator of ler) mutant of this strain, enhanced bacterial adherence to HEp-2 epithelial cells of the sdiA mutant strains relative to the strains containing a wild-type copy of sdiA. Quantitative reverse transcription PCR showed that the expression of LEE-encoded genes ler, espA and eae in strains with the sdiA deletions was not significantly different from that of the strains wild-type for sdiA. Similarly, no additional increases in the expression of LEE genes were observed in a sdiA hha double mutant strain relative to that observed in the hha deletion mutant. While the expression of fliC, which encodes flagellin, was enhanced in the sdiA mutant strain, the expression of fliC was reduced by several fold in the hha mutant strain, irrespective of the presence or absence of sdiA, indicating that the genes sdiA and hha exert opposing effects on the expression of fliC. The strains with deletions in sdiA or hha showed enhanced expression of csgA, encoding curlin of the curli fimbriae, with the expression of csgA highest in the sdiA hha double mutant, suggesting an additive effect of these two gene deletions on the expression of csgA. No significant differences were observed in the expression of the genes lpfA and fimA of the operons encoding long polar and type 1 fimbriae in the sdiA mutant strain. These data indicate that SdiA has no significant effect on the expression of LEE genes, but that it appears to act as a strong repressor of genes encoding flagella and curli fimbriae, and the alleviation of the SdiA-mediated repression of these genes in an EHEC O157 : H7 sdiA mutant strain contributes to enhanced bacterial motility and increased adherence to HEp-2 epithelial cells.

scholarly journals 125 THE ROLE OF ETHYLENE IN THE DEVELOPMENT OF CONSTANT-LIGHT INJURY OF POTATO

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 446c-446
Author(s):  
K. E. Cushman ◽  
T. W. Tibbitts
Keyword(s):  
Solanum Tuberosum ◽  
Leaf Tissue ◽  
Dry Weight ◽  
Light Period ◽  
Constant Light ◽  
Silver Thiosulfate ◽  
Ethylene Action ◽  
Teflon Film ◽  
Necrotic Spotting

Chlorosis and necrotic spotting develop on expanding leaves of particular cultivars of potato (Solanum tuberosum L.) when grown under constant light and temperature conditions. Plantlets of a constant-light sensitive cultivar, Kennebec, were planted into peat:vermiculite and established at 18C for 10 d under a 12 h light: 12 h dark photoperiod. Plants were then exposed to constant light and sprayed with 1 ml of either 0.5 mM silver thiosulfate (STS), an ethylene-action inhibitor, or water (as a control) every 2 days. Specific `target' leaflets, 5-10 mm in length at the beginning of the constant-light period, were harvested on days 5-9 of constant light, during injury development, and placed in bags made of Teflon film for IO-15 minutes to collect ethylene. Ethylene release and necrotic spotting increased as days of constant light increased for both water and STS-treated leaves, though STS-treated leaves produced slightly less ethylene and significantly less necrotic spotting than water-treated leaves. Ethylene release was correlated with extent of necrotic spotting. STS-treated plants exhibited greater dry weight and leaf area then water-treated plants. The results indicate that ethylene is not only produced by injured leaf tissue but, in addition, that ethylene may have a role in the development of constant-light injury symptoms.

scholarly journals Role of Mcpip1 in obesity-induced hepatic steatosis as determined by myeloid and liver-specific conditional knockouts

2020 ◽  
Author(s):  
Natalia Pydyn ◽  
Dariusz Żurawek ◽  
Joanna Kozieł ◽  
Edyta Kuś ◽  
Kamila Wojnar-Lason ◽  
...  
Keyword(s):  
Glucose Metabolism ◽  
Hepatic Steatosis ◽  
Systemic Inflammation ◽  
Hepatic Metabolism ◽  
Negative Regulator ◽  
Chow Diet ◽  
Alcoholic Fatty Liver ◽  
Hepatic Expression ◽  
Expression Of Genes ◽  
Myeloid Leukocytes

AbstractMonocyte chemoattractant protein-induced protein 1 (MCPIP1, alias Regnase1) is a negative regulator of inflammation, acting through cleavage of transcripts coding for proinflammatory cytokines and by inhibition of NFκB activity. Moreover, it was demonstrated, that MCPIP1 regulates lipid metabolism both in adipose tissue and hepatocytes. In this study, we investigated the effects of tissue-specific Mcpip1 deletion on the regulation of hepatic metabolism and development of non-alcoholic fatty liver disease (NAFLD).We used knock-in control Mcpip1fl/fl mice and animals with deletion of Mcpip1 in myeloid leukocytes (Mcpip1fl/flLysMCre) and in hepatocytes (Mcpip1fl/flAlbCre), which were fed chow or a high-fat diet (HFD) for 12 weeks. Mcpip1fl/flLysMCre mice were fed a chow diet were characterized by a significantly reduced hepatic expression of genes regulating lipid and glucose metabolism, which subsequently resulted in hypoglycemia and dyslipidemia. These animals also displayed systemic inflammation, demonstrated by increased concentrations of cytokines in the plasma. On the other hand, there were no significant changes in phenotype in Mcpip1fl/flAlbCre mice. Although we detected a reduced hepatic expression of genes regulating glucose metabolism and β-oxidation in these mice, they remained asymptomatic. Upon feeding them a HFD, Mcpip1fl/flLysMCre mice did not develop obesity, glucose intolerance, nor hepatic steatosis, but were characterized by hypoglycemia and dyslipidemia, along with proinflammatory phenotype with symptoms of cachexia. Mcpip1fl/flAlbCre animals, following a HFD, became hypercholesterolemic, but accumulated lipids in the liver at the same level as Mcpip1fl/fl mice, and no changes in the level of soluble factors tested in the plasma were detected.In conclusion, we have demonstrated that Mcpip1 protein plays an important role in the liver homeostasis. Depletion of Mcpip1 in myeloid leukocytes, followed by systemic inflammation, has a more pronounced effect on controlling liver metabolism and homeostasis than the depletion of Mcpip1 in hepatocytes.

scholarly journals Nucleoside 5′-Phosphoramidates Control the Phenylpropanoid Pathway in Vitis vinifera Suspension-Cultured Cells

2021 ◽  
Vol 22 (24) ◽  
pp. 13567
Author(s):  
Małgorzata Pietrowska-Borek ◽  
Jędrzej Dobrogojski ◽  
Anna Maria Wojdyła-Mamoń ◽  
Joanna Romanowska ◽  
Justyna Gołębiewska ◽  
...  
Keyword(s):  
Vitis Vinifera ◽  
Cultured Cells ◽  
Lignin Content ◽  
Cinnamyl Alcohol Dehydrogenase ◽  
Dry Weight ◽  
Phenylpropanoid Pathway ◽  
Stilbene Synthase ◽  
Signal Molecules ◽  
Suspension Cultured Cells ◽  
Expression Of Genes

It is known that cells contain various uncommon nucleotides such as dinucleoside polyphosphates (NpnN’s) and adenosine 5′-phosphoramidate (NH2-pA) belonging to nucleoside 5′-phosphoramidates (NH2-pNs). Their cellular levels are enzymatically controlled. Some of them are accumulated in cells under stress, and therefore, they could act as signal molecules. Our previous research carried out in Arabidopsis thaliana and grape (Vitis vinifera) showed that NpnN’s induced the expression of genes in the phenylpropanoid pathway and favored the accumulation of their products, which protect plants against stress. Moreover, we found that NH2-pA could play a signaling role in Arabidopsis seedlings. Data presented in this paper show that exogenously applied purine (NH2-pA, NH2-pG) and pyrimidine (NH2-pU, NH2-pC) nucleoside 5′-phosphoramidates can modify the expression of genes that control the biosynthesis of both stilbenes and lignin in Vitis vinifera cv. Monastrell suspension-cultured cells. We investigated the expression of genes encoding for phenylalanine ammonia-lyase (PAL1), cinnamate-4-hydroxylase (C4H1), 4-coumarate:coenzyme A ligase (4CL1), chalcone synthase (CHS1), stilbene synthase (STS1), cinnamoyl-coenzyme A:NADP oxidoreductase (CCR2), and cinnamyl alcohol dehydrogenase (CAD1). Each of the tested NH2-pNs also induced the expression of the trans-resveratrol cell membrane transporter VvABCG44 gene and caused the accumulation of trans-resveratrol and trans-piceid in grape cells as well as in the culture medium. NH2-pC, however, evoked the most effective induction of phenylpropanoid pathway genes such as PAL1, C4H1, 4CL1, and STS1. Moreover, this nucleotide also induced at short times the accumulation of N-benzoylputrescine (BenPut), one of the phenylamides that are derivatives of phenylpropanoid and polyamines. The investigated nucleotides did not change either the lignin content or the cell dry weight, nor did they affect the cell viability throughout the experiment. The results suggest that nucleoside 5′-phosphoramidates could be considered as new signaling molecules.

scholarly journals H2O2 Activates the Nuclear Localization of Msn2 and Maf1 through Thioredoxins in Saccharomyces cerevisiae

2009 ◽  
Vol 8 (9) ◽  
pp. 1429-1438 ◽  
Author(s):  
Stéphanie Boisnard ◽  
Gilles Lagniel ◽  
Cecilia Garmendia-Torres ◽  
Mikael Molin ◽  
Emmanuelle Boy-Marcotte ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cellular Response ◽  
Wide Spectrum ◽  
Stress Conditions ◽  
Negative Regulator ◽  
Nuclear Accumulation ◽  
Cell Defense ◽  
Expression Of Genes ◽  
Thioredoxin System ◽  
Enhanced Expression

ABSTRACT The cellular response to hydrogen peroxide (H2O2) is characterized by a repression of growth-related processes and an enhanced expression of genes important for cell defense. In budding yeast, this response requires the activation of a set of transcriptional effectors. Some of them, such as the transcriptional activator Yap1, are specific to oxidative stress, and others, such as the transcriptional activators Msn2/4 and the negative regulator Maf1, are activated by a wide spectrum of stress conditions. How these general effectors are activated in response to oxidative stress remains an open question. In this study, we demonstrate that the two cytoplasmic thioredoxins, Trx1 and Trx2, are essential to trigger the nuclear accumulation of Msn2/4 and Maf1, specifically under H2O2 treatment. Contrary to the case with many stress conditions previously described for yeast, the H2O2-induced nuclear accumulation of Msn2 and Maf1 does not correlate with the downregulation of PKA kinase activity. Nevertheless, we show that PP2A phosphatase activity is essential for driving Maf1 dephosphorylation and its subsequent nuclear accumulation in response to H2O2 treatment. Interestingly, under this condition, the lack of PP2A activity has no impact on the subcellular localization of Msn2, demonstrating that the H2O2 signaling pathways share a common route through the thioredoxin system and then diverge to activate Msn2 and Maf1, the final integrators of these pathways.

scholarly journals The Histone-Like Nucleoid Structuring Protein (H-NS) Is a Negative Regulator of the Lateral Flagellar System in the Deep-Sea Bacterium Shewanella piezotolerans WP3

2016 ◽  
Vol 82 (8) ◽  
pp. 2388-2398 ◽  
Author(s):  
Huahua Jian ◽  
Guanpeng Xu ◽  
Yingbao Gai ◽  
Jun Xu ◽  
Xiang Xiao
Keyword(s):  
Deep Sea ◽  
Negative Regulator ◽  
Mobility Shift ◽  
Swarming Motility ◽  
Content Type ◽  
Cold Environments ◽  
Expression Of Genes ◽  
Gel Mobility Shift ◽  
Pressure Stress ◽  
Flagellar Genes

ABSTRACTAlthough the histone-like nucleoid structuring protein (H-NS) is well known for its involvement in the adaptation of mesophilic bacteria, such asEscherichia coli, to cold environments and high-pressure stress, an understanding of the role of H-NS in the cold-adapted benthic microorganisms that live in the deep-sea ecosystem, which covers approximately 60% of the earth's surface, is still lacking. In this study, we characterized the function of H-NS inShewanella piezotoleransWP3, which was isolated from West Pacific sediment at a depth of 1,914 m. Anhnsgene deletion mutant (WP3Δhns) was constructed, and comparative whole-genome microarray analysis was performed. H-NS had a significant influence (fold change, >2) on the expression of a variety of WP3 genes (274 and 280 genes were upregulated and downregulated, respectively), particularly genes related to energy production and conversion. Notably, WP3Δhnsexhibited higher expression levels of lateral flagellar genes than WP3 and showed enhanced swarming motility and lateral flagellar production compared to those of WP3. The DNA gel mobility shift experiment showed that H-NS bound specifically to the promoter of lateral flagellar genes. Moreover, the high-affinity binding sequences of H-NS were identified by DNase I protection footprinting, and the results support the “binding and spreading” model for H-NS functioning. To our knowledge, this is the first attempt to characterize the function of the universal regulator H-NS in a deep-sea bacterium. Our data revealed that H-NS has a novel function as a repressor of the expression of genes related to the energy-consuming secondary flagellar system and to swarming motility.

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