scholarly journals Study of the regulatory mechanism involved in dark-induced Postharvest leaf senescence

2009 ◽  
Author(s):  
Amnon Lers ◽  
Gan Susheng
Keyword(s):  
Leaf Senescence ◽  
Regulatory Mechanism ◽  
Regulatory Gene ◽  
Leafy Vegetables ◽  
Regulatory Mechanisms ◽  
Protein Accumulation ◽  
Regulatory Sequences ◽  
Promoter Trap ◽  
Detached Leaves ◽  
Functional Analyses

Postharvest leaf senescence contributes to quality losses in flowers and leafy vegetables. The general goal of this research project was to investigate the regulatory mechanisms involved in dark-induced leaf senescence. The regulatory system involved in senescence induction and control is highly complex and possibly involves a network of senescence promoting pathways responsible for activation of the senescence-associated genes. Pathways involving different internal signals and environmental factors may have distinctive importance in different leaf senescence systems. Darkness is known to have a role in enhancement of postharvest leaf senescence and for getting an insight into its regulatory mechanism/s we have applied molecular genetics and functional genomics approaches. The original objectives were: 1. Identification of dark-induced SAGs in Arabidopsis using enhancer/promoter trap lines and microarray approaches; 2. Molecular and functional characterization of the identified genes by analyzing their expression and examining the phenotypes in related knockout mutant plants; 3. Initial studies of promoter sequences for selected early dark-induced SAGs. Since genomic studies of senescence, with emphasis on dark-induced senescence, were early-on published which included information on potential regulatory genes we decided to use this new information. This is instead of using the uncharacterized enhancer/promoter trap lines as originally planned. We have also focused on specific relevant genes identified in the two laboratories. Based on the available genomic analyses of leaf senescence 10 candidate genes hypothesized to have a regulatory role in dark-induced senescence were subjected to both expression as well as functional analyses. For most of these genes senescence-specific regulation was confirmed, however, functional analyses using knock-out mutants indicated no consequence to senescence progression. The transcription factor WARK75 was found to be specifically expressed during natural and dark-induced leaf senescence. Functional analysis demonstrated that in detached leaves senescence under darkness was significantly delayed while no phenotypic consequences could be observed on growth and development, including no effect on natural leaf senescence,. Thus, WARKY75 is suggested to have a role in dark-induced senescence, but not in natural senescence. Another regulatory gene identified to have a role in senescence is MKK9 encoding for a Mitogen-Activated Protein Kinase Kinase 9 which is upregulated during senescence in harvested leaves as well as in naturally senescing leaves. MKK9 can specifically phosphorylate another kinase, MPK6. Both knockouts of MKK9 and MPK6 displayed a significantly senescence delay in harvested leaves and possibly function as a phosphorelay that regulates senescence. To our knowledge, this is the first report that clearly demonstrates the involvement of a MAP kinase pathway in senescence. This research not only revealed a new signal transduction pathway, but more important provided significant insights into the regulatory mechanisms underlying senescence in harvested leaves. In an additional line of research we have employed the promoter of the senescence-induced BFN1 gene as a handle for identifying components of the regulatory mechanism. This gene was shown to be activated during darkinduced senescence of detached leaves, as well as natural senescence. This was shown by following protein accumulation and promoter activity which demonstrated that this promoter is activated during dark-induced senescence. Analysis of the promoter established that, at least some of the regulatory sequences reside in an 80 bps long fragment of the promoter. Overall, progress was made in identification of components with a role in dark-induced senescence in this project. Further studies should be done in order to better understand the function of these components and develop approaches for modulating the progress of senescence in crop plants for the benefit of agriculture.  

scholarly journals Low Light/Darkness as Stressors of Multifactor-Induced Senescence in Rice Plants

2021 ◽  
Vol 22 (8) ◽  
pp. 3936
Author(s):  
Ahmed G. Gad ◽  
Habiba ◽  
Xiangzi Zheng ◽  
Ying Miao
Keyword(s):  
Leaf Senescence ◽  
Crop Yields ◽  
Crop Improvement ◽  
Light Response ◽  
Development Stage ◽  
Regulatory Mechanisms ◽  
Economic Losses ◽  
Low Light ◽  
Chlorophyll Breakdown ◽  
Premature Leaf Senescence

Leaf senescence, as an integral part of the final development stage for plants, primarily remobilizes nutrients from the sources to the sinks in response to different stressors. The premature senescence of leaves is a critical challenge that causes significant economic losses in terms of crop yields. Although low light causes losses of up to 50% and affects rice yield and quality, its regulatory mechanisms remain poorly elucidated. Darkness-mediated premature leaf senescence is a well-studied stressor. It initiates the expression of senescence-associated genes (SAGs), which have been implicated in chlorophyll breakdown and degradation. The molecular and biochemical regulatory mechanisms of premature leaf senescence show significant levels of redundant biomass in complex pathways. Thus, clarifying the regulatory mechanisms of low-light/dark-induced senescence may be conducive to developing strategies for rice crop improvement. This review describes the recent molecular regulatory mechanisms associated with low-light response and dark-induced senescence (DIS), and their effects on plastid signaling and photosynthesis-mediated processes, chloroplast and protein degradation, as well as hormonal and transcriptional regulation in rice.

scholarly journals Involvement of microRNA in Solid Cancer: Role and Regulatory Mechanisms

Biomedicines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 343
Author(s):  
Ying-Chin Lin ◽  
Tso-Hsiao Chen ◽  
Yu-Min Huang ◽  
Po-Li Wei ◽  
Jung-Chun Lin
Keyword(s):  
Gene Expression ◽  
Regulatory Mechanism ◽  
Transcriptional Factor ◽  
Regulatory Mechanisms ◽  
Solid Cancer ◽  
Detailed Knowledge ◽  
Altered Expression ◽  
Human Malignancy ◽  
Regulated Expression ◽  
Pivotal Mechanism

MicroRNAs (miRNAs) function as the post-transcriptional factor that finetunes the gene expression by targeting to the specific candidate. Mis-regulated expression of miRNAs consequently disturbs gene expression profile, which serves as the pivotal mechanism involved in initiation or progression of human malignancy. Cancer-relevant miRNA is potentially considered the therapeutic target or biomarker toward the precise treatment of cancer. Nevertheless, the regulatory mechanism underlying the altered expression of miRNA in cancer is largely uncovered. Detailed knowledge regarding the influence of miRNAs on solid cancer is critical for exploring its potential of clinical application. Herein, we elucidate the regulatory mechanism regarding how miRNA expression is manipulated and its impact on the pathogenesis of distinct solid cancer.

scholarly journals Transcription Factors and microRNA Genes Regulatory Network Construction Under Drought Stress in Sesame (Sesamum indicum L.)

2020 ◽  
Author(s):  
Mohammad Amin Baghery ◽  
Seyed Kamal Kazemitabar ◽  
Ali Dehestani ◽  
Pooyan Mehrabanjoubani ◽  
Mohammad Mehdi Naghizadeh ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Drought Stress ◽  
Gene Networks ◽  
Regulatory Networks ◽  
Regulatory Gene ◽  
Sesamum Indicum ◽  
Regulatory Mechanisms ◽  
Oilseed Crop ◽  
Sesame Genotypes ◽  
Almost All

Abstract Background: Drought is one of the most common environmental stresses affecting crops yield and quality. Sesame is an important oilseed crop that most likely faces drought during its growth due to growing in semi-arid and arid areas. Plants responses to drought controlled by regulatory mechanisms. Despite this importance, there is little information about Sesame regulatory mechanisms against drought stress. Results: 458 drought-related genes were identified using comprehensive RNA-seq data analysis of two susceptible and tolerant sesame genotypes under drought stress. These drought-responsive genes were included secondary metabolites biosynthesis-related Like F3H, sucrose biosynthesis-related like SUS2, transporters like SUC2, and protectives like LEA and HSP families. Interactions between identified genes and regulators including TFs and miRNAs were predicted using bioinformatics tools and related regulatory gene networks were constructed. Key regulators and relations of Sesame under drought stress were detected by network analysis. TFs belonged to DREB (DREB2D), MYB (MYB63), ZFP (TFIIIA), bZIP (bZIP16), bHLH (PIF1), WRKY (WRKY30) and NAC (NAC29) families were found among key regulators. mRNAs like miR399, miR169, miR156, miR5685, miR529, miR395, miR396, and miR172 also found as key drought regulators. Furthermore, a total of 117 TFs and 133 miRNAs that might be involved in drought stress were identified with this approach. Conclusions: Most of the identified TFs and almost all of the miRNAs are introduced for the first time as potential regulators of drought response in Sesame. These regulators accompany with identified drought-related genes could be valuable candidates for future studies and breeding programs on Sesame under drought stress. Keywords: Sesamum indicum, Drought stress, Regulatory networks, miRNA, Transcription Factors.

scholarly journals Altered Glut-2 accumulation and β-cell function in mice lacking the exocrine-specific transcription factor, Mist1

2005 ◽  
Vol 187 (3) ◽  
pp. 407-418 ◽  
Author(s):  
E N Fazio ◽  
M Everest ◽  
R Colman ◽  
R Wang ◽  
C L Pin
Keyword(s):  
Transcription Factor ◽  
Glucose Tolerance ◽  
Cell Function ◽  
Regulatory Gene ◽  
Immunohistochemical Analysis ◽  
Endocrine Function ◽  
Pancreatic Acinar Cells ◽  
Protein Accumulation ◽  
Specific Transcription Factor ◽  
And Function

Mist1 is an exocrine-specific transcription factor that is necessary for the establishment of cell organization and function of pancreatic acinar cells. While Mist1 is not expressed in the endocrine pancreas, the disorganized phenotype of the exocrine component may affect endocrine function. Therefore, we examined endocrine tissue morphology and function in Mist1-knockout (Mist1KO) mice. Endocrine function was evaluated using a glucose-tolerance test on 2–10-month-old female mice and revealed a significant reduction in glucose-clearing ability in 10-month-old Mist1KO mice compared with wild-type mice. Immunohistochemical analysis of islet hormone expression indicated that the decreased endocrine function was not due to a decrease in insulin-, glucagon- or somatostatin-expressing cells. However, a decrease in the size of islets in 10-month-old Mist1KO mice was observed along with a decrease in Glut-2 protein accumulation. These results suggest that the islets in Mist1KO mice are functionally compromised, likely accounting for the decreased glucose tolerance. Based on these findings, we have identified that the loss of a regulatory gene in the exocrine compartment can affect the endocrine component, providing a possible link between susceptibility for various pancreatic diseases.

scholarly journals XGef Mediates Early CPEB Phosphorylation duringXenopusOocyte Meiotic Maturation

2005 ◽  
Vol 16 (3) ◽  
pp. 1152-1164 ◽  
Author(s):  
Susana E. Martínez ◽  
Lei Yuan ◽  
Charlemagne Lacza ◽  
Heather Ransom ◽  
Gwendolyn M. Mahon ◽  
...  
Keyword(s):  
Oocyte Maturation ◽  
Regulatory Mechanism ◽  
Meiotic Maturation ◽  
Protein Accumulation ◽  
Interacting Protein ◽  
Meiotic Progression ◽  
Messenger Ribonucleoprotein ◽  
Guanine Exchange Factor ◽  
Exchange Activity

Polyadenylation-induced translation is an important regulatory mechanism during metazoan development. During Xenopus oocyte meiotic progression, polyadenylation-induced translation is regulated by CPEB, which is activated by phosphorylation. XGef, a guanine exchange factor, is a CPEB-interacting protein involved in the early steps of progesterone-stimulated oocyte maturation. We find that XGef influences early oocyte maturation by directly influencing CPEB function. XGef and CPEB interact during oogenesis and oocyte maturation and are present in a c-mos messenger ribonucleoprotein (mRNP). Both proteins also interact directly in vitro. XGef overexpression increases the level of CPEB phosphorylated early during oocyte maturation, and this directly correlates with increased Mos protein accumulation and acceleration of meiotic resumption. To exert this effect, XGef must retain guanine exchange activity and the interaction with CPEB. Overexpression of a guanine exchange deficient version of XGef, which interacts with CPEB, does not enhance early CPEB phosphorylation. Overexpression of a version of XGef that has significantly reduced interaction with CPEB, but retains guanine exchange activity, decreases early CPEB phosphorylation and delays oocyte maturation. Injection of XGef antibodies into oocytes blocks progesterone-induced oocyte maturation and early CPEB phosphorylation. These findings indicate that XGef is involved in early CPEB activation and implicate GTPase signaling in this process.

scholarly journals Ideology as a normative - regulatory mechanism in the history of the society

KANT ◽  
2021 ◽  
Vol 38 (1) ◽  
pp. 119-126
Author(s):  
Maria Vladimirovna Ivanova
Keyword(s):  
Political Ideology ◽  
Regulatory Mechanism ◽  
Modern Society ◽  
Social Regulation ◽  
Regulatory Mechanisms ◽  
Regulatory Function ◽  
Traditional Society ◽  
The Third ◽  
Public Consciousness ◽  
History Of

The article is devoted to the study of the phenomenon of ideology in the context of its normative and regulatory function. The author's contribution to the further knowledge of the ideology was the following main conclusions. The emergence of ideology as a regulatory mechanism was primarily due to the transition from a traditional society to a modern one. Ideology is an attribute of modern society, since it acts as an intermediary between a person and social reality, determining and regulating the activities of all people and relations between them in any sphere of society. In the XIX – first half of the XX centuries political ideology in its theoretical form dominated. As a regulatory mechanism, it functioned alongside religion, morality, and law, complementing them. In the second half of the XX – XXI centuries, as a result of the third STR, ideology in an ordinary and practical form became widespread. It began to replace the traditional regulatory mechanisms, surpassing them in the degree of influence on public consciousness and becoming the main mechanism of social regulation.

scholarly journals SPECTRAL CHARACTERISTICS OF TUNDRA AND FOREST TUNDRA LANDSCAPES DURING THE YEARS OF SUMMER TEMPERATURE ANOMALIES

2020 ◽  
Vol 4 ◽  
pp. 88-103
Author(s):  
T.B. Titkova ◽  
◽  
A.N. Zolotokrylin ◽  
V.V. Vinogradov ◽  
◽  
...  
Keyword(s):  
Surface Temperature ◽  
Regulatory Mechanism ◽  
Spectral Characteristics ◽  
Extreme Temperature ◽  
Regulatory Mechanisms ◽  
Spectral Parameters ◽  
Vegetation Diversity ◽  
Forest Tundra ◽  
Temperature Anomalies ◽  
Novaya Zemlya

The warming at high latitudes, remaining in recent years, has a direct impact on arctic and subarctic landscapes. Possible changes of this landscapes under the climate warming are closely related with regulatory mechanisms for the underlying surface temperature. The circumstances of forming radiation and evapotranspirational regulatory mechanisms for the surface temperature were explored for tundra (from arctic to southern) and forest tundra landscapes of Novaya Zemlya and Western Siberia. The MODIS data of surface spectral characteristics were used, and more specifically albedo (Al) and surface temperature (Ts) for July 2000-2019. The work shows that the radiation regulatory mechanism of the surface temperature is dominated in glacial and polar desert landscapes of Arctic and Subarctic with a predominance of stony and rubble types of surfaces with lichens. At the same time, radiative surface temperature control mechanism in mountain and arctic tundra of Novaya Zemlya almost does not depend on weather anomalies and so far has a little implication for the temperature trend. In the mainland and forest tundra, the evapotranspirational regulatory mechanism for the surface temperature starts to prevail. This is supported by the increasing of monthly average air temperatures to 15-16°С, which is beneficial to the vegetation diversity. In subzones of the southern and forest tundra, the connection of albedo and surface temperature depends on altitudes, slope exposure and especially on extreme temperature anomalies. In basins, or hydromorphic complexes, in cold years against the backdrop of wetlands the regulatory mechanism for the surface temperature prevails, and in warm years the humidity decreasing leads to the highest vegetation development and the connection type can turn into the evapotranspirational one. On the high grounds the return process is observed, which is also connected with the changes in humidification conditions. In forest tundra, where the air temperature rises and the canopy height increases, the evapotranspirational mechanism of spectral parameters Al–Ts connections is weakening. As a result, in southern and forest tundra two balanced steady states of the connection types of surface spectral characteristics can exist in relation to lighting conditions and temperature anomalies.

Gene regulation and cell heredity

1997 ◽  
Author(s):  
John Maynard Smith ◽  
Eors Szathmary
Keyword(s):  
Gene Regulation ◽  
Regulatory Gene ◽  
Regulatory Protein ◽  
Regulatory Elements ◽  
Regulatory Proteins ◽  
Regulatory Sequence ◽  
Regulatory Sequences ◽  
Cellular Mechanisms ◽  
E Coli ◽  
Average Gene

Two cellular mechanisms are essential for development. The first, gene regulation, makes it possible to switch on different genes in different cells, in response either to conditions external to the cell or to the activity of other genes within the cell. The second, cell heredity, ensures that these states of gene activity, once induced, can be stably transmitted through cell division, without the need for the continued presence of an external inducer. In this chapter, we describe how gene regulation and cell heredity are achieved in metazoans, and point to some similar mechanisms that are already present in prokaryotes. The central problem of gene regulation was posed, in a social context, by the scholastic Master Eckhardt: ‘Quis custodiet ipsos custodes?’ [Who regulates the regulators?] Clearly, the proposition that every gene needs a separate regulator gene leads to an infinite regress. There are various ways of resolving the paradox, which include one regulator controls several other genes, including regulators; one gene, even a regulator, is controlled by several other genes; and some genes may be both regulatory and structural. Plenty of examples are known for each case. It is also necessary that some genes be regulated by signals from outside the cell. The essential mechanism of gene regulation was discovered by Jacob & Monod (1961; Fig. 13.1) in E. coli. A regulatory gene codes for a protein, which, by binding to a specific regulatory sequence of another gene, alters the activity of that gene (negatively in the case originally described by Jacob & Monod, but the effect can also be positive). The regulation can be modified by a specific inducing molecule that alters the effect of the regulatory protein by binding to it allosterically. It is interesting that these two properties of regulatory proteins—that they can recognize specific regulatory sequences, and that their effectiveness can be altered by binding allosterically to inducers—are already present in prokaryotes. The complexity of multicellular eukaryotic development requires that an average gene be controlled by many others. Whereas regulatory elements in bacteria are usually simple switches, eukaryotes tend to have ‘smart’ genes, controlled by a complex of several regulatory proteins (Davidson, 1990; Beardsley, 1991).

scholarly journals Ancestral regulatory mechanisms specify conserved midbrain circuitry in arthropods and vertebrates

2020 ◽  
Vol 117 (32) ◽  
pp. 19544-19555 ◽  
Author(s):  
Jessika C. Bridi ◽  
Zoe N. Ludlow ◽  
Benjamin Kottler ◽  
Beate Hartmann ◽  
Lies Vanden Broeck ◽  
...  
Keyword(s):  
Neural Development ◽  
Gene Networks ◽  
Motor Coordination ◽  
Regulatory Elements ◽  
Regulatory Mechanisms ◽  
Cell Protein ◽  
Specific Gene ◽  
Regulatory Sequences ◽  
Embryonic Mouse ◽  
And Function

Corresponding attributes of neural development and function suggest arthropod and vertebrate brains may have an evolutionarily conserved organization. However, the underlying mechanisms have remained elusive. Here, we identify a gene regulatory and character identity network defining the deutocerebral–tritocerebral boundary (DTB) inDrosophila. This network comprises genes homologous to those directing midbrain-hindbrain boundary (MHB) formation in vertebrates and their closest chordate relatives. Genetic tracing reveals that the embryonic DTB gives rise to adult midbrain circuits that in flies control auditory and vestibular information processing and motor coordination, as do MHB-derived circuits in vertebrates. DTB-specific gene expression and function are directed bycis-regulatory elements of developmental control genes that include homologs of mammalianZinc finger of the cerebellumandPurkinje cell protein 4.DrosophilaDTB-specificcis-regulatory elements correspond to regulatory sequences of humanENGRAILED-2, PAX-2, andDACHSHUND-1that direct MHB-specific expression in the embryonic mouse brain. We show thatcis-regulatory elements and the gene networks they regulate direct the formation and function of midbrain circuits for balance and motor coordination in insects and mammals. Regulatory mechanisms mediating the genetic specification of cephalic neural circuits in arthropods correspond to those in chordates, thereby implying their origin before the divergence of deuterostomes and ecdysozoans.

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