scholarly journals Transduction of Signals during Somatic Embryogenesis

Plants ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 178
Author(s):  
Mohamed Elhiti ◽  
Claudio Stasolla
Keyword(s):  
Somatic Embryogenesis ◽  
Stress Responses ◽  
Biological Process ◽  
Somatic Cells ◽  
Developmental Pathway ◽  
Embryogenic Cells ◽  
Master Regulators ◽  
Whole Plants

Somatic embryogenesis (SE) is an in vitro biological process in which bipolar structures (somatic embryos) can be induced to form from somatic cells and regenerate into whole plants. Acquisition of the embryogenic potential in culture is initiated when some competent cells within the explants respond to inductive signals (mostly plant growth regulators, PRGs), and de-differentiate into embryogenic cells. Such cells, “canalized” into the embryogenic developmental pathway, are able to generate embryos comparable in structure and physiology to their in vivo counterparts. Genomic and transcriptomic studies have identified several pathways governing the initial stages of the embryogenic process. In this review, the authors emphasize the importance of the developmental signals required for the progression of embryo development, starting with the de-differentiation of somatic cells and culminating with tissue patterning during the formation of the embryo body. The action and interaction of PGRs are highlighted, along with the participation of master regulators, mostly transcription factors (TFs), and proteins involved in stress responses and the signal transduction required for the initiation of the embryogenic process.

scholarly journals Biological control of strawberry crown rot, root rot and grey mould by the beneficial fungus Aureobasidium pullulans

BioControl ◽  
2021 ◽  
Author(s):  
Mudassir Iqbal ◽  
Maha Jamshaid ◽  
Muhammad Awais Zahid ◽  
Erik Andreasson ◽  
Ramesh R. Vetukuri ◽  
...  
Keyword(s):  
Root Rot ◽  
Fungal Pathogens ◽  
Aureobasidium Pullulans ◽  
Grey Mould ◽  
Lesion Size ◽  
Plant Diseases ◽  
Crown Rot ◽  
Whole Plants

AbstractUtilization of biocontrol agents is a sustainable approach to reduce plant diseases caused by fungal pathogens. In the present study, we tested the effect of the candidate biocontrol fungus Aureobasidium pullulans (De Bary) G. Armaud on strawberry under in vitro and in vivo conditions to control crown rot, root rot and grey mould caused by Phytophthora cactorum (Lebert and Cohn) and Botrytis cinerea Pers, respectively. A dual plate confrontation assay showed that mycelial growth of P. cactorum and B. cinerea was reduced by 33–48% when challenged by A. pullulans as compared with control treatments. Likewise, detached leaf and fruit assays showed that A. pullulans significantly reduced necrotic lesion size on leaves and disease severity on fruits caused by P. cactorum and B. cinerea. In addition, greenhouse experiments with whole plants revealed enhanced biocontrol efficacy against root rot and grey mould when treated with A. pullulans either in combination with the pathogen or pre-treated with A. pullulans followed by inoculation of the pathogens. Our results demonstrate that A. pullulans is an effective biocontrol agent to control strawberry diseases caused by fungal pathogens and can be an effective alternative to chemical-based fungicides.

scholarly journals NIK promotes metabolic adaptation of glioblastoma cells to bioenergetic stress

2021 ◽  
Vol 12 (3) ◽  
Author(s):  
Michael L. Kamradt ◽  
Ji-Ung Jung ◽  
Kathryn M. Pflug ◽  
Dong W. Lee ◽  
Victor Fanniel ◽  
...  
Keyword(s):  
Stress Responses ◽  
Glucose Deprivation ◽  
Metabolic Adaptation ◽  
Mitochondrial Morphology ◽  
Atp Production ◽  
Tumor Microenvironments ◽  
Iκb Kinase ◽  
Critical Measure

AbstractCancers, including glioblastoma multiforme (GBM), undergo coordinated reprogramming of metabolic pathways that control glycolysis and oxidative phosphorylation (OXPHOS) to promote tumor growth in diverse tumor microenvironments. Adaptation to limited nutrient availability in the microenvironment is associated with remodeling of mitochondrial morphology and bioenergetic capacity. We recently demonstrated that NF-κB-inducing kinase (NIK) regulates mitochondrial morphology to promote GBM cell invasion. Here, we show that NIK is recruited to the outer membrane of dividing mitochondria with the master fission regulator, Dynamin-related protein1 (DRP1). Moreover, glucose deprivation-mediated metabolic shift to OXPHOS increases fission and mitochondrial localization of both NIK and DRP1. NIK deficiency results in decreased mitochondrial respiration, ATP production, and spare respiratory capacity (SRC), a critical measure of mitochondrial fitness. Although IκB kinase α and β (IKKα/β) and NIK are required for OXPHOS in high glucose media, only NIK is required to increase SRC under glucose deprivation. Consistent with an IKK-independent role for NIK in regulating metabolism, we show that NIK phosphorylates DRP1-S616 in vitro and in vivo. Notably, a constitutively active DRP1-S616E mutant rescues oxidative metabolism, invasiveness, and tumorigenic potential in NIK−/− cells without inducing IKK. Thus, we establish that NIK is critical for bioenergetic stress responses to promote GBM cell pathogenesis independently of IKK. Our data suggest that targeting NIK may be used to exploit metabolic vulnerabilities and improve therapeutic strategies for GBM.

scholarly journals PGC7 suppresses TET3 for protecting DNA methylation

2013 ◽  
Vol 42 (5) ◽  
pp. 2893-2905 ◽  
Author(s):  
Chunjing Bian ◽  
Xiaochun Yu
Keyword(s):  
Dna Methylation ◽  
Molecular Mechanism ◽  
Biological Process ◽  
Cpg Islands ◽  
Binding Motifs ◽  
Genome Wide Analysis ◽  
Dna Motif ◽  
Genome Wide

Abstract Ten-eleven translocation (TET) family enzymes convert 5-methylcytosine to 5-hydroxylmethylcytosine. However, the molecular mechanism that regulates this biological process is not clear. Here, we show the evidence that PGC7 (also known as Dppa3 or Stella) interacts with TET2 and TET3 both in vitro and in vivo to suppress the enzymatic activity of TET2 and TET3. Moreover, lacking PGC7 induces the loss of DNA methylation at imprinting loci. Genome-wide analysis of PGC7 reveals a consensus DNA motif that is recognized by PGC7. The CpG islands surrounding the PGC7-binding motifs are hypermethylated. Taken together, our study demonstrates a molecular mechanism by which PGC7 protects DNA methylation from TET family enzyme-dependent oxidation.

MondoA Drives B-ALL Malignancy through Enhanced Adaptation to Metabolic Stress

Blood ◽  
2021 ◽  
Author(s):  
Alexandra Sipol ◽  
Erik Hameister ◽  
Busheng Xue ◽  
Julia Hofstetter ◽  
Maxim Barenboim ◽  
...  
Keyword(s):  
Stress Responses ◽  
Lymphoblastic Leukemia ◽  
Metabolic Stress ◽  
Tca Cycle ◽  
Underlying Mechanism ◽  
Patient Data ◽  
Data Sets ◽  
Dependent Manner

Cancer cells are in most instances characterized by rapid proliferation and uncontrolled cell division. Hence, they must adapt to proliferation-induced metabolic stress through intrinsic or acquired anti-metabolic stress responses to maintain homeostasis and survival. One mechanism to achieve this is to reprogram gene expression in a metabolism-dependent manner. MondoA (also known as MLXIP), a member of the MYC interactome, has been described as an example of such a metabolic sensor. However, the role of MondoA in malignancy is not fully understood and the underlying mechanism in metabolic responses remains elusive. By assessing patient data sets we found that MondoA overexpression is associated with a worse survival in pediatric common acute lymphoblastic leukemia (B-ALL). Using CRISPR/Cas9 and RNA interference approaches, we observed that MondoA depletion reduces transformational capacity of B-ALL cells in vitro and dramatically inhibits malignant potential in an in vivo mouse model. Interestingly, reduced expression of MondoA in patient data sets correlated with enrichment in metabolic pathways. The loss of MondoA correlated with increased tricarboxylic acid (TCA) cycle activity. Mechanistically, MondoA senses metabolic stress in B-ALL cells by restricting oxidative phosphorylation through reduced PDH activity. Glutamine starvation conditions greatly enhance this effect and highlight the inability to mitigate metabolic stress upon loss of MondoA in B-ALL. Our findings give a novel insight into the function of MondoA in pediatric B-ALL and support the notion that MondoA inhibition in this entity offers a therapeutic opportunity and should be further explored.

scholarly journals In vivo and in vitro studies on heavy metal tolerance in Sesbania grandiflora L

2009 ◽  
Vol 3 (2) ◽  
pp. 48-64
Author(s):  
Kadhim M. Ibrahim ◽  
Shaimaa A. Yousir
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Tolerance ◽  
Heavy Metal Tolerance ◽  
Heavy Metal Concentration ◽  
Callus Cultures ◽  
Metal Levels ◽  
Whole Plants

Several experiments were carried out to study heavy metal tolerance in tissue cultures or whole plants of S. grandiflora., Callus was induced and maintained on modified Murashige and Skoog, 1962 medium (MS) supplemented with (0.5)mg/l benzyl adenine and (2)mg/l 2,4-phenoxy acetic acid . Heavy metals (Cd, Co, Cu, Cr or Zn) were added to the culture medium at different concentrations as contamination agents. In order to asses the effect of these heavy metals on seed germination; seeds were sown in soil contaminated with different concentrations of heavy metals for 3 weeks. Atomic Absorption Spectrophotometer was used for analysis of samples taken from whole plants and callus cultures. Results showed that callus fresh weight decreased with increasing heavy metal concentration in cultural medium. Germination percentages and plant heights increased over time. However, a reduction occurred in these parameters with increasing heavy metal levels. Percentages of metals accumulated in calli were (0.001, 0.011, 0.012 and 0.013%) at (0.0, 0.05, 0.075 and 0.1)mg/l Cd respectively; (0.001, 0.008, 0.016 and 0.006%) at (0.0, 0.1, 0.25 and 0.5)mg/l Co respectively; (0.001, 0.020, 0.034 and 0.015%) at (0.0, 0.075, 0.2 and 0.5)mg/l Cu respectively; (0.001, 0.013, 0.012 and 0.010%) at (0.0, 0.25, 0.4 and 0.5)mg/l Cr respectively and (0.027, 0.051, 0.059 and 0.056%) at (0.0 , 0.75, 1.0 and 1.5)mg/l Zn respectively. Percentages of metals accumulated in whole plants were (0.08, 0.55, 1.11, 0.83 and 0.44%) at (0.0, 1.0, 2.0, 3.0 and 4.0)mg/Kg soil Cd respectively; (0.11, 0.22, 0.55, 0.47 and 0.44%) at (0.0, 15.0, 30.0 45.0 and 60.0)mg/Kg soil Co respectively; (0.01, 0.10, 0.57, 0.58 and 0.72%) at (0.0, 25.0, 50.0, 75.0 and 100.0)mg/Kg soil Cu respectively. (0.08, 0.80, 1.28, 1.31 and 0.88%) at (0.0, 25.0, 50.0, 75.0 and 100.0)mg/Kg soil Cr respectively and (0.06, 1.11, 1.20, 1.83 and 2.22%) at (0.0, 100.0, 200.0, 300.0 and 400.0)mg/Kg soil Zn respectively.

scholarly journals Cardenolides, toxicity, and the costs of sequestration in the coevolutionary interaction between monarchs and milkweeds

2021 ◽  
Vol 118 (16) ◽  
pp. e2024463118
Author(s):  
Anurag A. Agrawal ◽  
Katalin Böröczky ◽  
Meena Haribal ◽  
Amy P. Hastings ◽  
Ronald A. White ◽  
...  
Keyword(s):  
Danaus Plexippus ◽  
Monarch Butterfly ◽  
Chemical Defenses ◽  
Trade Off ◽  
Asclepias Curassavica ◽  
Plant Chemical ◽  
Whole Plants ◽  
Benefits And Costs

For highly specialized insect herbivores, plant chemical defenses are often co-opted as cues for oviposition and sequestration. In such interactions, can plants evolve novel defenses, pushing herbivores to trade off benefits of specialization with costs of coping with toxins? We tested how variation in milkweed toxins (cardenolides) impacted monarch butterfly (Danaus plexippus) growth, sequestration, and oviposition when consuming tropical milkweed (Asclepias curassavica), one of two critical host plants worldwide. The most abundant leaf toxin, highly apolar and thiazolidine ring–containing voruscharin, accounted for 40% of leaf cardenolides, negatively predicted caterpillar growth, and was not sequestered. Using whole plants and purified voruscharin, we show that monarch caterpillars convert voruscharin to calotropin and calactin in vivo, imposing a burden on growth. As shown by in vitro experiments, this conversion is facilitated by temperature and alkaline pH. We next employed toxin-target site experiments with isolated cardenolides and the monarch’s neural Na+/K+-ATPase, revealing that voruscharin is highly inhibitory compared with several standards and sequestered cardenolides. The monarch’s typical >50-fold enhanced resistance to cardenolides compared with sensitive animals was absent for voruscharin, suggesting highly specific plant defense. Finally, oviposition was greatest on intermediate cardenolide plants, supporting the notion of a trade-off between benefits and costs of sequestration for this highly specialized herbivore. There is apparently ample opportunity for continued coevolution between monarchs and milkweeds, although the diffuse nature of the interaction, due to migration and interaction with multiple milkweeds, may limit the ability of monarchs to counteradapt.

scholarly journals REGULATION OF CEREAL EMBRYONIC ORGANOGENESIS IN VITRO CONDITIONS

ÈKOBIOTEH ◽  
2021 ◽  
Vol 4 (1) ◽  
pp. 11-23
Author(s):  
N.N. Kruglova ◽  
Keyword(s):  
Somatic Embryogenesis ◽  
Hormonal Regulation ◽  
Zygotic Embryogenesis ◽  
Review Of The Literature ◽  
Biological Phenomenon ◽  
Organogenesis In Vitro ◽  
Cereal Embryos ◽  
Plant Embryogenesis

The article provides the brief review of the literature and own works devoted to the peculiarities of the cereal embryonic organogenesis at the early stages of ontogenesis in the conditions of in vitro culture (the so-called somatic embryogenesis, or embryoidogenesis in vitro). Particular attention is paid to the issues of hormonal regulation of the development of somatic cereal embryos from initial cells to mature structures in vitro. A comparison of somatic embryogenesis in vitro with similar events in zygotic embryogenesis in vivo confirms the validity of the principle of universality of morphogenesis processes in vivo and in vitro (Batygina, 2014). The prospects of using somatic embryogenesis in vitro as a model for studying the most complex biological phenomenon – zygotic plant embryogenesis in vivo – are discussed.

Glucose homeostasis and hypothalamic-pituitary-adrenocortical axis during development in rats

1990 ◽  
Vol 259 (5) ◽  
pp. E601-E613 ◽  
Author(s):  
E. P. Widmaier
Keyword(s):  
Stress Responses ◽  
Adrenocorticotropic Hormone ◽  
Glucose Sensor ◽  
Adult Life ◽  
Glucose Sensing ◽  
Physiological Data ◽  
Compensatory Mechanisms ◽  
Definition Of

Glucoprivation represents a model stress in which activation of different stress responses at different ages can be monitored both in vivo and in vitro. Physiological data indicate rat brain contains a liver/pancreas-type glucose sensor, yet no biochemical or immunocytochemical evidence exists for such a sensor. Young rats appear to lack normal hypothalamic glucose-sensing ability and do not show typical secretory patterns of corticotropin-releasing factor, adrenocorticotropic hormone, or corticosterone after experimentally induced glucoprivation. However, they hypersecrete catecholamines and glucagon (compared with adults) and thrive on fuel sources other than glucose that are abundant after birth. High steroid levels during the first 24 h after birth may be critical for inducing gluconeogenic enzymes and promoting differentiation of tissues like pancreas. Neonatal rats also have unique control systems to combat the damaging effects of other stresses like hypoxia; these systems may disappear in adults. Thus the definition of stress may change during development, and the compensatory mechanisms employed to combat stress change from neonatal to adult life and are intricately related to the metabolic needs of the animal.

scholarly journals Protective Effect of Coconut Oil Meal Phenolic Antioxidants against Macromolecular Damage: In Vitro and In Vivo Study

2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
A. N. Karunasiri ◽  
C. M. Senanayake ◽  
H. Hapugaswatta ◽  
N. Jayathilaka ◽  
K. N. Seneviratne
Keyword(s):  
Oxidative Stress ◽  
Protective Effect ◽  
Stress Responses ◽  
Coconut Oil ◽  
Oral Feeding ◽  
Phenolic Antioxidants ◽  
Significant Difference ◽  
Macromolecular Damage

Coconut oil meal, a cheap by-product of coconut oil production, is a rich source of phenolic antioxidants. Many age-related diseases are caused by reactive oxygen species- (ROS-) induced damage to macromolecules such as lipids, proteins, and DNA. In the present study, the protective effect of the phenolic extract of coconut oil meal (CMPE) against macromolecular oxidative damage was evaluated using in vitro and in vivo models. Sunflower oil, bovine serum albumin (BSA), and plasmid DNA were used in the in vitro study, and thiobarbituric acid reactive substances (TBARS), protein carbonyl, and nicked DNA were evaluated as oxidation products. The inhibitory effect of CMPE against H2O2-induced macromolecular damage was evaluated using cultured HEp-2 cells. The results indicate that CMPE inhibits macromolecular damage both in vitro and in vivo. In addition, CMPE regulates redox status of HEp-2 cells under oxidative stress conditions by maintaining higher reduced glutathione levels. There was no significant difference in the expression of glutathione peroxidase in stressed and unstressed cells suggesting that CMPE regulates the cellular oxidative stress responses without affecting the expression of oxidative stress response genes. Oral feeding of Wistar rats with CMPE improves the serum and plasma antioxidant status without causing any toxic effects.

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