scholarly journals Alkyl gallates display elicitor activities in tobacco plants

2017 ◽  
Author(s):  
Pascale Goupil ◽  
Razik Benouaret ◽  
Claire Richard
Keyword(s):  
Cell Death ◽  
Plasma Membrane ◽  
Target Genes ◽  
Crop Protection ◽  
Membrane Properties ◽  
List Type ◽  
Ethyl Gallate ◽  
Tobacco Plants ◽  
Tobacco Leaves ◽  
Alkyl Gallates

AbstractAlkyl gallates showed elicitor activities on tobacco in both whole plants and cell suspensions. Methyl gallate (MG), ethyl gallate (EG) and n-propyl gallate (PG) infiltration into tobacco leaves induced hypersensitive reaction-like lesions and topical production of autofluorescent compounds revealed under UV light. When sprayed on tobacco plants at 5 mM, EG promoted upregulation of defence-related genes such as the antimicrobial PR1, β-1,3-glucanase PR2, chitinase PR3 and osmotin PR5 target genes. Tobacco BY-2 cells challenged with EG underwent cell death in 48 h, significantly reduced in the presence of the protease inhibitor aprotinin. The three alkyl gallates all caused alkalinisation of the BY-2 extracellular medium, whereas gallic acid did not trigger any pH variation. Using EGTA or LaCl3, we showed that Ca2+ mobilisation occurred in BY-2 cells elicited with EG. Overall, our findings are the first evidence of alkyl gallate elicitor properties with early perception events on plasma membrane, potential hypersensitive reactions and PR-related downstream defence responses in tobacco.Highlights–Alkyl gallates elicited defence reactions in tobacco–Alkyl gallates induced local biochemical changes in tobacco leaves–Alkyl gallates caused modification of plasma membrane properties–Ethyl gallate led to defence transcript accumulation and dose-dependent cell death associated with hypersensitive response–Alkyl gallates are novel elicitor agents well-suited to crop protection schemes.

vitreal cells and specialized phagocytes in the chick embryo retina: A TEM and SEM study

1990 ◽  
Vol 48 (3) ◽  
pp. 330-331
Author(s):  
M.A. Cuadros ◽  
M.J. Martinez-Guerrero ◽  
A. Rios
Keyword(s):  
Cell Death ◽  
Plasma Membrane ◽  
Acid Phosphatase ◽  
Chick Embryo ◽  
Basement Membrane ◽  
Sem Images ◽  
Intimate Contact ◽  
Cellular Processes ◽  
Sem Study ◽  
Free Cells

In the chick embryo retina (days 3-4 of incubation), coinciding with an increase in cell death, specialized phagocytes characterized by intense acid phosphatase activity have been described. In these preparations, all free cells in the vitreal humor (vitreal cells) were strongly labeled. Conventional TEM and SEM techniques were used to characterize them and attempt to determine their relationship with retinal phagocytes.Two types of vitreal cells were distinguished. The first are located at some distance from the basement membrane of the neuroepithelium, and are rounded, with numerous vacuoles and thin cytoplasmic prolongations. Images of exo- and or endocytosis were frequent; the cells showed a well-developed Golgi apparatus (Fig. 1) In SEM images, the cells was covered with short cellular processes (Fig. 3). Cells lying parallel to or alongside the basement membrane are elongated. The plasma membrane is frequently in intimate contact with the basement membrane. These cells have generally a large cytoplasmic expansion (Fig. 5).

Agrobacteium Transformation of Tobacco with a Genetic Module of Antimalarial Agent Artemisinin Biosynthesis

2020 ◽  
Vol 36 (3) ◽  
pp. 34-45
Author(s):  
T.Yu. Mitiuchkina ◽  
A.S. Pushin ◽  
A.K. Tzareva ◽  
A.M. Vainstein ◽  
S.V. Dolgov
Keyword(s):  
Target Genes ◽  
Artemisia Annua ◽  
Biosynthesis Pathway ◽  
Expression Systems ◽  
Heterologous Host ◽  
Russian Science ◽  
Tobacco Plants ◽  
Genetic Module ◽  
Heterologous Expression Systems ◽  
Artemisinin Biosynthesis

Artemisinin-based medicines are the most effective treatment for malaria. To date, the wormwood plants (Artemisia annua L.) are the main source of artemisinin. Due to the limited nature of this source, considerable efforts are directed towards the development of methods for artemisinin production via heterologous expression systems. We used in this study agrobacterial transformation to transfer the genetic module of the artemisinin biosynthesis pathway into plants and then analyzed its transcription in a heterologous host. Tobacco plants were transformed with the artemisinin biosynthesis genes encoding amorpha-4,11-diene synthase, artemisin-aldehyde All(13) reductase, amorpha-4,11-diene monooxygenase, cytochrome P450 reductase from A. annua and yeast 3-hydroxy-3-methylglutaryl-coenzyme A reductase cloned in the pArtemC vector; farnesyl diphosphate synthase and aldehyde dehydrogenase were used to transform the plants as parts of vector p2356. As a result of transformation with the pArtemC and p2356 vectors, in twos transgenic lines with all target genes were obtained. Five genes of artemisinin biosynthesis and two genes of biosynthesis of its precursors were successfully transferred into the genome of transgenic tobacco lines as a result of the co-transformation with abovementioned vectors. Thus, the entire artemisinin biosynthesis pathway was first reconstructed in heterologous plants: the transcription of the artemisinin biosynthesis genes in the tobacco plants was shown via RT-PCR. The obtained results will be used in further research on expression systems for the production of artemisinin and other non-protein substances in heterologous host plants. artemisinin, malaria, metabolic engineering, tobacco, transgenic plants This work was supported by a Grant from the Russian Science Foundation no. 19-14-00190.

scholarly journals Phenothiazines alter plasma membrane properties and sensitize cancer cells to injury by inhibiting annexin-mediated repair

2021 ◽  
pp. 101012
Author(s):  
Anne Sofie Busk Heitmann ◽  
Ali Asghar Hakami Zanjani ◽  
Martin Berg Klenow ◽  
Anna Mularski ◽  
Stine Lauritzen Sønder ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Cancer Cells ◽  
Membrane Properties

scholarly journals Fatty Acid Hydroperoxides and H2O2 in the Execution of Hypersensitive Cell Death in Tobacco Leaves

2005 ◽  
Vol 138 (3) ◽  
pp. 1516-1526 ◽  
Author(s):  
Jean-Luc Montillet ◽  
Sangpen Chamnongpol ◽  
Christine Rustérucci ◽  
James Dat ◽  
Brigitte van de Cotte ◽  
...  
Keyword(s):  
Cell Death ◽  
Fatty Acid ◽  
Hypersensitive Cell Death ◽  
Tobacco Leaves ◽  
Fatty Acid Hydroperoxides

scholarly journals Id2 Promotes Apoptosis by a Novel Mechanism Independent of Dimerization to Basic Helix-Loop-Helix Factors

1998 ◽  
Vol 18 (9) ◽  
pp. 5435-5444 ◽  
Author(s):  
Monica Florio ◽  
Maria-Clemencia Hernandez ◽  
Hui Yang ◽  
Hui-Kuo Shu ◽  
John L. Cleveland ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Cell Death ◽  
Target Genes ◽  
Specific Binding ◽  
Helix Loop Helix ◽  
Cell Death Pathway ◽  
Id Proteins ◽  
Enhanced Expression ◽  
Positive Regulators ◽  
Hlh Transcription Factors

ABSTRACT Members of the helix-loop-helix (HLH) family of Id proteins have demonstrated roles in the regulation of differentiation and cell proliferation. Id proteins inhibit differentiation by HLH-mediated heterodimerization with basic HLH transcription factors. This blocks their sequence-specific binding to DNA and activation of target genes that are often expressed in a tissue-specific manner. Id proteins can also act as positive regulators of cell proliferation. The different mechanisms proposed for Id-mediated promotion of entry into S phase also involve HLH-mediated interactions affecting regulators of the G1/S transition. We have found that Id2 augments apoptosis in both interleukin-3 (IL-3)-dependent 32D.3 myeloid progenitors and U2OS osteosarcoma cells. We could not detect a similar activity for Id3. In contrast to the effects of Id2 on differentiation and cell proliferation, Id2-mediated apoptosis is independent of HLH-mediated dimerization. The ability of Id2 to promote cell death resides in its N-terminal region and is associated with the enhanced expression of a known component of the programmed cell death pathway, the proapoptotic gene BAX.

scholarly journals An Early and Robust Activation of Caspases Heads Cells for a Regulated Form of Necrotic-like Cell Death

2015 ◽  
Vol 290 (34) ◽  
pp. 20841-20855 ◽  
Author(s):  
Mercè Garcia-Belinchón ◽  
María Sánchez-Osuna ◽  
Laura Martínez-Escardó ◽  
Carla Granados-Colomina ◽  
Sònia Pascual-Guiral ◽  
...  
Keyword(s):  
Cell Death ◽  
Plasma Membrane ◽  
Chromatin Condensation ◽  
Biochemical Network ◽  
Display Type ◽  
Nuclear Morphology ◽  
Type Ii ◽  
Caspase Activation ◽  
Membrane Leakage ◽  
Nuclear Alterations

Apoptosis is triggered by the activation of caspases and characterized by chromatin condensation and nuclear fragmentation (type II nuclear morphology). Necrosis is depicted by a gain in cell volume (oncosis), swelling of organelles, plasma membrane leakage, and subsequent loss of intracellular contents. Although considered as different cell death entities, there is an overlap between apoptosis and necrosis. In this sense, mounting evidence suggests that both processes can be morphological expressions of a common biochemical network known as “apoptosis-necrosis continuum.” To gain insight into the events driving the apoptosis-necrosis continuum, apoptotically proficient cells were screened facing several apoptotic inducers for the absence of type II apoptotic nuclear morphologies. Chelerythrine was selected for further studies based on its cytotoxicity and the lack of apoptotic nuclear alterations. Chelerythrine triggered an early plasma membrane leakage without condensed chromatin aggregates. Ultrastructural analysis revealed that chelerythrine-mediated cytotoxicity was compatible with a necrotic-like type of cell death. Biochemically, chelerythrine induced the activation of caspases. Moreover, the inhibition of caspases prevented chelerythrine-triggered necrotic-like cell death. Compared with staurosporine, chelerythrine induced stronger caspase activation detectable at earlier times. After using a battery of chemicals, we found that high concentrations of thiolic antioxidants fully prevented chelerythrine-driven caspase activation and necrotic-like cell death. Lower amounts of thiolic antioxidants partially prevented chelerythrine-mediated cytotoxicity and allowed cells to display type II apoptotic nuclear morphology correlating with a delay in caspase-3 activation. Altogether, these data support that an early and pronounced activation of caspases can drive cells to undergo a form of necrotic-like regulated cell death.

Tobacco Leaf Grading Based on Deep Convolutional Neural Networks and Machine Vision

2021 ◽  
Vol 65 (1) ◽  
pp. 11-22
Author(s):  
Mengyao Lu ◽  
Shuwen Jiang ◽  
Cong Wang ◽  
Dong Chen ◽  
Tian’en Chen
Keyword(s):  
Neural Networks ◽  
Deep Learning ◽  
Transfer Learning ◽  
Convolutional Neural Networks ◽  
Classification Accuracy ◽  
Classification Model ◽  
List Type ◽  
Tobacco Leaves ◽  
Tobacco Leaf ◽  
Grading Model

HighlightsA classification model for the front and back sides of tobacco leaves was developed for application in industry.A tobacco leaf grading method that combines a CNN with double-branch integration was proposed.The A-ResNet network was proposed and compared with other classic CNN networks.The grading accuracy of eight different grades was 91.30% and the testing time was 82.180 ms, showing a relatively high classification accuracy and efficiency.Abstract. Flue-cured tobacco leaf grading is a key step in the production and processing of Chinese-style cigarette raw materials, directly affecting cigarette blend and quality stability. At present, manual grading of tobacco leaves is dominant in China, resulting in unsatisfactory grading quality and consuming considerable material and financial resources. In this study, for fast, accurate, and non-destructive tobacco leaf grading, 2,791 flue-cured tobacco leaves of eight different grades in south Anhui Province, China, were chosen as the study sample, and a tobacco leaf grading method that combines convolutional neural networks and double-branch integration was proposed. First, a classification model for the front and back sides of tobacco leaves was trained by transfer learning. Second, two processing methods (equal-scaled resizing and cropping) were used to obtain global images and local patches from the front sides of tobacco leaves. A global image-based tobacco leaf grading model was then developed using the proposed A-ResNet-65 network, and a local patch-based tobacco leaf grading model was developed using the ResNet-34 network. These two networks were compared with classic deep learning networks, such as VGGNet, GoogLeNet-V3, and ResNet. Finally, the grading results of the two grading models were integrated to realize tobacco leaf grading. The tobacco leaf classification accuracy of the final model, for eight different grades, was 91.30%, and grading of a single tobacco leaf required 82.180 ms. The proposed method achieved a relatively high grading accuracy and efficiency. It provides a method for industrial implementation of the tobacco leaf grading and offers a new approach for the quality grading of other agricultural products. Keywords: Convolutional neural network, Deep learning, Image classification, Transfer learning, Tobacco leaf grading

Relationship Between Mesophyll Conductance to CO2 Diffusion and Contents of Aquaporin Localized at Plasma Membrane in Tobacco Plants Grown Under Drought Conditions

2008 ◽  
pp. 805-808 ◽  
Author(s):  
Shin-Ichi Miyazawa ◽  
Satomi Yoshimura ◽  
Yuki Shinzaki ◽  
Masayoshi Maeshima ◽  
Chikahiro Miyake
Keyword(s):  
Plasma Membrane ◽  
Mesophyll Conductance ◽  
Tobacco Plants ◽  
Co2 Diffusion ◽  
Drought Conditions

scholarly journals Functions for Cdc42p BEM Adaptors in Regulating a Differentiation-Type MAP Kinase Pathway

2019 ◽  
Author(s):  
Sukanya Basu ◽  
Beatriz González ◽  
Boyang Li ◽  
Garrett Kimble ◽  
Keith G. Kozminski ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Cell Polarity ◽  
Rho Gtpase ◽  
Mapk Pathway ◽  
Mitogen Activated Protein Kinase ◽  
List Type ◽  
Activation Kinetics ◽  
Closed Conformation ◽  
Mapk Pathways ◽  
Effector Pathways

ABSTRACTRho GTPases regulate cell polarity and signal transduction pathways to control morphogenetic responses in different settings. In yeast, the Rho GTPase Cdc42p regulates cell polarity, and through the p21-activated kinase Ste20p, Cdc42p also regulates mitogen-activated protein kinase (MAPK) pathways (mating, filamentous growth or fMAPK, and HOG). Although much is known about how Cdc42p regulates cell polarity and the mating pathway, how Cdc42p regulates the fMAPK pathway is not clear. To address this question, Cdc42p-dependent MAPK pathways were compared in the filamentous (∑1278b) strain background. Each MAPK pathway showed a unique activation profile, with the fMAPK pathway exhibiting slow activation kinetics compared to the mating and HOG pathways. A previously characterized version of Cdc42p, Cdc42pE100A, that is specifically defective for fMAPK pathway signaling, was defective for interaction with Bem4p, the pathway-specific adaptor for the fMAPK pathway. Corresponding residues in Bem4p were identified that were required for interaction with Cdc42p and fMAPK pathway signaling. The polarity adaptor Bem1p also regulated the fMAPK pathway. In the fMAPK pathway, Bem1p recruited Ste20p to the plasma membrane, cycled between an open and closed conformation, and interacted with the GEF for Cdc42, Cdc24p. Bem1p also regulated effector pathways in different ways, behaving as a multi-functional adaptor in some pathways and an inert scaffold in others. Genetic suppression tests showed that Bem4p and Bem1p regulate the fMAPK pathway in an ordered sequence. Collectively, the study demonstrates unique and sequential functions for Rho GTPase adaptors in regulating MAPK pathways.HIGHLIGHTSComparing Cdc42p-dependent MAPK pathways showed that the fMAPK pathway had slow activation kinetics compared to the mating and HOG pathways.A collection of cdc42 alleles was tested for MAPK pathway functions. § Cdc42pE100A, previously characterized as being specifically defective for fMAPK signaling, showed reduced interaction with the fMAPK pathway adaptor Bem4p.§ Corresponding residues in Bem4p were identified that were required for interaction with Cdc42p and fMAPK signaling.The polarity adaptor Bem1p regulated the fMAPK pathway. § Bem1p regulated the fMAPK pathway by recruiting Ste20p to the plasma membrane, cycling between an open and closed conformation, and interacting with the Cdc42p GEF, Cdc24p.Different domains of Bem1p had different roles in regulating effector pathways. § Bem1p may function as a multi-functional adaptor in some pathways and an inert scaffold in others.Bem4p and Bem1p regulated the fMAPK pathway in an ordered sequence. § The data support a model where Bem4p recruits Cdc24p to GDP-Cdc42p, and Bem1p directs GTP-Cdc42p to Ste20p at the plasma membrane.§ The bud-site GTPase Rsr1p regulates Cdc24p in the fMAPK pathway but does not initiate signaling.

scholarly journals The Role of BCL6 in Glioblastoma

2021 ◽  
Author(s):  
◽  
Nicole Jones
Keyword(s):  
Dna Damage ◽  
Cell Death ◽  
Target Genes ◽  
Therapy Resistance ◽  
Response To Therapy ◽  
Transcriptional Analysis ◽  
Luciferase Reporter ◽  
Mobility Shift ◽  
Response To Chemotherapy ◽  
Targeted Inhibition

<p>Glioblastoma (GBM) is the most common and most deadly brain tumour to occur in adults. Initially patients respond to radiation and chemotherapy, which primarily work by causing large amounts of DNA damage, leading to cell death. However, this process does not happen effectively in GBM and understanding how these cells resist cell death in response to therapy is key to improving the efficacy of treatment. BCL6 is a transcription factor that stops cell death in response to DNA damage, primarily through repressing transcription of DNA damage response genes. Recent work in our lab has shown BCL6 to be present in untreated GBM tumours and up-regulated in GBM cells treated with chemotherapy or radiation, and inhibition of BCL6 leads to a profound loss in proliferative activity. These results indicate that BCL6 may be used as a mechanism of therapy resistance in GBM cells. The objective of this study was to establish a role for BCL6 in GBM cells using luciferase reporter assays, electrophoretic mobility shift assays (EMSA), quantitative chromatin immunoprecipitation (qChIP) and targeted inhibition of BCL6 with subsequent transcriptional analysis by RNA sequencing. We observed that BCL6 appeared to be a transcriptional activator in GBM, as shown by increased luciferase activity in GBM cells treated with radiation. EMSA experiments revealed that overexpressed BCL6 formed complexes with co-repressors, but endogenous BCL6 did not. qChIP experiments revealed that BCL6 was not bound to tradtional BCL6 target genes. Analysis of transcriptional profiles has identified a unique subset of genes which are downregulated when BCL6 is inhibited and upregulated in response to chemotherapy, and these genes were related to cell survival. These changes indicate that these genes may be regulated by BCL6 in chemotherapy treated cells. Together, these results illustrate that BCL6 appears to have an active and unique function in GBM cells, and reinforces this transcription factors position as an attractive therapeutic target in GBM.</p>

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