scholarly journals Phospholipase Dα1 acts as a negative regulator of high Mg2+-induced leaf senescence in Arabidopsis

2021 ◽  
Author(s):  
Daniela Kocourková ◽  
Kristýna Kroumanov ◽  
Tereza Podmanick ◽  
Michal Daněk ◽  
Jan Martinec
Keyword(s):  
Stress Response ◽  
Leaf Senescence ◽  
Growth And Development ◽  
Starch Content ◽  
Proline Content ◽  
Negative Regulator ◽  
Knockout Mutant ◽  
Phosphate Homeostasis ◽  
Cellular Processes ◽  
Premature Leaf Senescence

Magnesium is a macronutrient involved in essential cellular processes. Its deficiency or excess is a stress factor for plants, seriously affecting their growth and development and therefore, its accurate regulation is essential. Recently, we discovered that phospholipase Dα1 (PLDα1) activity is vital in the stress response to high-magnesium conditions in Arabidopsis roots. This study shows that PLDα1 acts as a negative regulator of high-Mg2+-induced leaf senescence in Arabidopsis. The level of phosphatidic acid produced by PLDα1 and the amount of PLDα1 in the leaves increase in plants treated with high Mg2+. A knockout mutant of PLDα1 (plda1-1), exhibits premature leaf senescence under high-Mg2+ conditions. In pldα1-1 plants, higher accumulation of abscisic and jasmonic acid and impaired magnesium, potassium and phosphate homeostasis were observed under high-Mg2+ conditions. High Mg2+ also led to an increase of starch and proline content in Arabidopsis plants. While the starch content was higher in plda1-1 plants, proline content was significantly lower in plda1-1 compared with WT. Our results show that PLDα1 is essential for Arabidopsis plants to cope with the pleiotropic effects of high-Mg2+ stress and delay the leaf senescence.

scholarly journals Phospholipase Dα1 Acts as a Negative Regulator of High Mg2+-Induced Leaf Senescence in Arabidopsis

2021 ◽  
Vol 12 ◽  
Author(s):  
Daniela Kocourková ◽  
Kristýna Kroumanová ◽  
Tereza Podmanická ◽  
Michal Daněk ◽  
Jan Martinec
Keyword(s):  
Leaf Senescence ◽  
Growth And Development ◽  
Starch Content ◽  
Proline Content ◽  
Negative Regulator ◽  
Wild Type ◽  
Knockout Mutant ◽  
Phosphate Homeostasis ◽  
Cellular Processes ◽  
Premature Leaf Senescence

Magnesium (Mg2+) is a macronutrient involved in essential cellular processes. Its deficiency or excess is a stress factor for plants, seriously affecting their growth and development and therefore, its accurate regulation is essential. Recently, we discovered that phospholipase Dα1 (PLDα1) activity is vital in the stress response to high-magnesium conditions in Arabidopsis roots. This study shows that PLDα1 acts as a negative regulator of high-Mg2+-induced leaf senescence in Arabidopsis. The level of phosphatidic acid produced by PLDα1 and the amount of PLDα1 in the leaves increase in plants treated with high Mg2+. A knockout mutant of PLDα1 (pldα1-1), exhibits premature leaf senescence under high-Mg2+ conditions. In pldα1-1 plants, higher accumulation of abscisic and jasmonic acid (JA) and impaired magnesium, potassium and phosphate homeostasis were observed under high-Mg2+ conditions. High Mg2+ also led to an increase of starch and proline content in Arabidopsis plants. While the starch content was higher in pldα1-1 plants, proline content was significantly lower in pldα1-1 compared with wild type plants. Our results show that PLDα1 is essential for Arabidopsis plants to cope with the pleiotropic effects of high-Mg2+ stress and delay the leaf senescence.

scholarly journals Characterization of Somatic Embryogenesis Receptor-Like Kinase 4 as a Negative Regulator of Leaf Senescence in Arabidopsis

Cells ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 50 ◽  
Author(s):  
Xiaoxu Li ◽  
Salman Ahmad ◽  
Akhtar Ali ◽  
Cun Guo ◽  
Hong Li ◽  
...  
Keyword(s):  
Somatic Embryogenesis ◽  
Leaf Senescence ◽  
Stress Responses ◽  
Negative Regulator ◽  
Knockout Mutant ◽  
Surface Receptors ◽  
Extracellular Signals ◽  
Early Leaf Senescence

Leaf senescence is a genetically controlled process that involves the perception of extracellular signals and signal transduction. The receptor-like protein kinases (RLKs) are known to act as an important class of cell surface receptors and are involved in multiple biological processes such as development and stress responses. The functions of a number of RLK members have been characterized in Arabidopsis and other plant species, but only a limited number of RLK proteins have been reported to be associated with leaf senescence. In the present study, we have characterized the role of the somatic embryogenesis receptor kinase 4 (SERK4) gene in leaf senescence. The expression of SERK4 was up-regulated during leaf senescence and by several abiotic stress treatments in Arabidopsis. The serk4-1 knockout mutant was found to display a significant early leaf senescence phenotype. Furthermore, the results of overexpression analysis and complementary analysis supported the idea that SERK4 acts as a negative regulator in the process of leaf senescence.

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 The co-chaperone Fkbp5 shapes the acute stress response in the paraventricular nucleus of the hypothalamus of male mice

2021 ◽  
Author(s):  
Alexander S. Häusl ◽  
Lea M. Brix ◽  
Jakob Hartmann ◽  
Max L. Pöhlmann ◽  
Juan-Pablo Lopez ◽  
...  
Keyword(s):  
Stress Response ◽  
Hpa Axis ◽  
Paraventricular Nucleus ◽  
Acute Stress ◽  
Negative Regulator ◽  
Neuron Activity ◽  
Cell Type ◽  
Specific Expression ◽  
Acute Stress Response ◽  
Cell Type Specific

AbstractDisturbed activation or regulation of the stress response through the hypothalamic-pituitary-adrenal (HPA) axis is a fundamental component of multiple stress-related diseases, including psychiatric, metabolic, and immune disorders. The FK506 binding protein 51 (FKBP5) is a negative regulator of the glucocorticoid receptor (GR), the main driver of HPA axis regulation, and FKBP5 polymorphisms have been repeatedly linked to stress-related disorders in humans. However, the specific role of Fkbp5 in the paraventricular nucleus of the hypothalamus (PVN) in shaping HPA axis (re)activity remains to be elucidated. We here demonstrate that the deletion of Fkbp5 in Sim1+ neurons dampens the acute stress response and increases GR sensitivity. In contrast, Fkbp5 overexpression in the PVN results in a chronic HPA axis over-activation, and a PVN-specific rescue of Fkbp5 expression in full Fkbp5 KO mice normalizes the HPA axis phenotype. Single-cell RNA sequencing revealed the cell-type-specific expression pattern of Fkbp5 in the PVN and showed that Fkbp5 expression is specifically upregulated in Crh+ neurons after stress. Finally, Crh-specific Fkbp5 overexpression alters Crh neuron activity, but only partially recapitulates the PVN-specific Fkbp5 overexpression phenotype. Together, the data establish the central and cell-type-specific importance of Fkbp5 in the PVN in shaping HPA axis regulation and the acute stress response.

Changes in levels of foliar carbohydrates and myo-inositol before premature leaf senescence of Populus nigra induced by a mixture of O3 and SO2

1996 ◽  
Vol 74 (6) ◽  
pp. 965-970 ◽  
Author(s):  
R. C. Fialho ◽  
J. Bücker
Keyword(s):  
Air Pollution ◽  
Leaf Senescence ◽  
Populus Nigra ◽  
Continuous Exposure ◽  
Nonstructural Carbohydrates ◽  
Progressive Decline ◽  
Total Nonstructural Carbohydrates ◽  
Leaf Yellowing ◽  
Premature Leaf Senescence ◽  
Early Indication

Specimens of Populus nigra L. cv. Loenen exhibit premature leaf senescence when exposed for a few weeks to realistic air pollution. In this study, the changes in levels of foliar carbohydrates and myo-inositol (MI) due to 30 ± 1 nL/L O3 + 12 ± 1 nL/L SO2 from the onset of exposure to the occurrence of premature abscission is presented. Petioles and laminae of the 12 oldest leaves were separately analysed on days 0, 4, 8, 12, 16, 20, 22, and 32 of continuous exposure, which was performed in open-top chambers (OTC). On days 8 to 12, clearly prior to yellowing (starting on day 22), total nonstructural carbohydrates (TNC; starch + raffinose + sucrose + glucose + fructose + MI) in the fumigated laminae exceeded that in controls by about 30%. This increase was due to higher amounts of different soluble forms, while starch remained unaltered. From day 20 onwards, the level of TNC in the fumigated laminae progressively fell below that in controls. This decrease was due to a progressive decline in starch, which had started on day 16 and was dominating, although glucose and raffinose increased significantly. In the petioles, starch, sucrose, and glucose decreased because of fumigation with the occurrence of leaf yellowing, while raffinose increased. In contrast, MI in the petioles progressively accumulated directly on exposure until leaf yellowing occurred. The results are discussed in terms of the "general adaption syndrome" of H. Selye (1936. Nature (London), 138: 32). The marked MI response in petioles is concluded to be an early indication of phytorelevant O3 + SO2 pollution. Keywords: air pollution, carbohydrates, myo-inositol, pigments, Populus nigra L., senescence, stress.

Transcriptomic Analysis of MSTN Knockout in the Early Differentiation of Chicken Fetal Myoblasts

Genes ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 58
Author(s):  
Ke Xu ◽  
Hao Zhou ◽  
Chengxiao Han ◽  
Zhong Xu ◽  
Jinmei Ding ◽  
...  
Keyword(s):  
Signaling Pathways ◽  
Molecular Mechanism ◽  
Growth And Development ◽  
Biological Effects ◽  
Muscle Growth ◽  
Negative Regulator ◽  
Myoblast Differentiation ◽  
Fatty Acid Binding ◽  
Knock Out ◽  
Early Differentiation

In mammals, Myostatin (MSTN) is a known negative regulator of muscle growth and development, but its role in birds is poorly understood. To investigate the molecular mechanism of MSTN on muscle growth and development in chickens, we knocked out MSTN in chicken fetal myoblasts (CFMs) and sequenced the mRNA transcriptomes. The amplicon sequencing results show that the editing efficiency of the cells was 76%. The transcriptomic results showed that 296 differentially expressed genes were generated after down-regulation of MSTN, including angiotensin I converting enzyme (ACE), extracellular fatty acid-binding protein (EXFABP) and troponin T1, slow skeletal type (TNNT1). These genes are closely associated with myoblast differentiation, muscle growth and energy metabolism. Subsequent enrichment analysis showed that DEGs of CFMs were related to MAPK, P13K/AKT, and STAT3 signaling pathways. The MAPK and P13K/AKT signaling pathways are two of the three known signaling pathways involved in the biological effects of MSTN in mammals, and the STAT3 pathway is also significantly enriched in MSTN knock out chicken leg muscles. The results of this study will help to understand the possible molecular mechanism of MSTN regulating the early differentiation of CFMs and lay a foundation for further research on the molecular mechanism of MSTN involvement in muscle growth and development.

scholarly journals Chromatin regulates expression of small RNAs to help maintain transposon methylome homeostasis in Arabidopsis

2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Ranjith K. Papareddy ◽  
Katalin Páldi ◽  
Subramanian Paulraj ◽  
Ping Kao ◽  
Stefan Lutzmayer ◽  
...  
Keyword(s):  
Growth And Development ◽  
Germ Line ◽  
Small Interfering Rnas ◽  
Chromatin States ◽  
Heterochromatin Formation ◽  
Cellular Processes ◽  
A Cell ◽  
Decondensed Chromatin ◽  
And Function ◽  
New Generation

Abstract Background Eukaryotic genomes are partitioned into euchromatic and heterochromatic domains to regulate gene expression and other fundamental cellular processes. However, chromatin is dynamic during growth and development and must be properly re-established after its decondensation. Small interfering RNAs (siRNAs) promote heterochromatin formation, but little is known about how chromatin regulates siRNA expression. Results We demonstrate that thousands of transposable elements (TEs) produce exceptionally high levels of siRNAs in Arabidopsis thaliana embryos. TEs generate siRNAs throughout embryogenesis according to two distinct patterns depending on whether they are located in euchromatic or heterochromatic regions of the genome. siRNA precursors are transcribed in embryos, and siRNAs are required to direct the re-establishment of DNA methylation on TEs from which they are derived in the new generation. Decondensed chromatin also permits the production of 24-nt siRNAs from heterochromatic TEs during post-embryogenesis, and siRNA production from bipartite-classified TEs is controlled by their chromatin states. Conclusions Decondensation of heterochromatin in response to developmental, and perhaps environmental, cues promotes the transcription and function of siRNAs in plants. Our results indicate that chromatin-mediated siRNA transcription provides a cell-autonomous homeostatic control mechanism to help reconstitute pre-existing chromatin states during growth and development including those that ensure silencing of TEs in the future germ line.

Gene mapping of starch accumulation and premature leaf senescence in the ossac3 mutant of rice

Euphytica ◽  
2018 ◽  
Vol 214 (10) ◽  
Author(s):  
Junyang Huang ◽  
Meng Yan ◽  
Xiaoyan Zhu ◽  
Ting Zhang ◽  
WenQiang Shen ◽  
...  
Keyword(s):  
Gene Mapping ◽  
Leaf Senescence ◽  
Starch Accumulation ◽  
Premature Leaf Senescence

scholarly journals Constitutive Photomorphogenic 1 Enhances ER Stress Tolerance in Arabidopsis

2021 ◽  
Vol 22 (19) ◽  
pp. 10772
Author(s):  
Chang Ho Kang ◽  
Eun Seon Lee ◽  
Ganesh M. Nawkar ◽  
Joung Hun Park ◽  
Seong Dong Wi ◽  
...  
Keyword(s):  
Stress Response ◽  
Er Stress ◽  
Stress Conditions ◽  
Negative Regulator ◽  
Light Signaling ◽  
Dependent Manner ◽  
Wild Type ◽  
Er Stress Response ◽  
The Unfolded Protein Response ◽  
Mutant Locus

Interaction between light signaling and stress response has been recently reported in plants. Here, we investigated the role of CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1), a key regulator of light signaling, in endoplasmic reticulum (ER) stress response in Arabidopsis. The cop1-4 mutant Arabidopsis plants were highly sensitive to ER stress induced by treatment with tunicarmycin (Tm). Interestingly, the abundance of nuclear-localized COP1 increased under ER stress conditions. Complementation of cop1-4 mutant plants with the wild-type or variant types of COP1 revealed that the nuclear localization and dimerization of COP1 are essential for its function in plant ER stress response. Moreover, the protein amount of ELONGATED HYPOCOTYL 5 (HY5), which inhibits bZIP28 to activate the unfolded protein response (UPR), decreased under ER stress conditions in a COP1-dependent manner. Accordingly, the binding of bZIP28 to the BIP3 promoter was reduced in cop1-4 plants and increased in hy5 plants compared with the wild type. Furthermore, introduction of the hy5 mutant locus into the cop1-4 mutant background rescued its ER stress-sensitive phenotype. Altogether, our results suggest that COP1, a negative regulator of light signaling, positively controls ER stress response by partially degrading HY5 in the nucleus.

scholarly journals VERSATILE ROLE OF AUXIN AND ITS CROSSTALK WITH OTHER PLANT HORMONES TO REGULATE PLANT GROWTH AND DEVELOPMENT

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Hammad Ishtiaq ◽  
Savita Bhardwaj ◽  
Aaliya Ashraf ◽  
Dhriti Kapoor
Keyword(s):  
Cell Cycle ◽  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Plant Hormones ◽  
Growth And Development ◽  
Naphthalene Acetic Acid ◽  
Plant Growth And Development ◽  
Indole Butyric Acid ◽  
Cellular Processes

Plant growth regulators are significant chemical compounds which are synthesized inside the plant cells and play vital role in plant growth and development. Such compounds are usually active at very low concentrations. These plant growth regulators act as a signalling molecule, which influences the growth of plants. Throughout the previous year’s remarkable investigation have been done for understanding the synthesis of auxin and its effect on various physiological progressions. Auxin is a plant hormone that is involved in various physiological activities, including basic cellular processes such as cell enlargement, regulation of the cell cycle and distinction progress. Plants and several other microorganisms together produce auxin in order to carry out their cell cycle. The chemically synthesized auxins like NAA (naphthalene acetic acid) and IBA (Indole- butyric acid), also take part in various cellular processes. Against various types of biotic and abiotic stress conditions, these plant hormones significantly contribute in promoting acclimatization and adaptation in combination with other phytohormones. The present review highlights some of the important features of auxin role in regulation of plant growth either alone or in crosstalk with other plant hormones.

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