scholarly journals Regulation of Shoot Apical Meristem and Axillary Meristem Development in Plants

2020 ◽  
Vol 21 (8) ◽  
pp. 2917 ◽  
Author(s):  
Zhihui Xue ◽  
Liya Liu ◽  
Cui Zhang
Keyword(s):  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Recent Progress ◽  
Life Cycles ◽  
Axillary Meristem ◽  
Epigenetic Factors ◽  
Meristem Development ◽  
And Function ◽  
The Impact

Plants retain the ability to produce new organs throughout their life cycles. Continuous aboveground organogenesis is achieved by meristems, which are mainly organized, established, and maintained in the shoot apex and leaf axils. This paper will focus on reviewing the recent progress in understanding the regulation of shoot apical meristem and axillary meristem development. We discuss the genetics of plant meristems, the role of plant hormones and environmental factors in meristem development, and the impact of epigenetic factors on meristem organization and function.

Physiological influences in the development and function of the shoot apical meristem of microspore-derived embryos of Brassica napus ‘Topas’

2006 ◽  
Vol 84 (3) ◽  
pp. 371-383 ◽  
Author(s):  
Nicole S. Ramesar-Fortner ◽  
Edward C. Yeung
Keyword(s):  
Brassica Napus ◽  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Radial Symmetry ◽  
Brassica Napus L ◽  
Conversion Frequency ◽  
Dramatic Decline ◽  
Meristem Development ◽  
Methylpropionic Acid ◽  
And Function

The effect of auxins and abscisic acid (ABA) on shoot apical meristem development and function was analyzed in microspore-derived embryos of Brassica napus L. ‘Topas’. Embryos were treated with an auxin transport inhibitor, tri-iodobenzoic acid (TIBA) or exogenous indole-3-acetic acid (IAA) at various stages during their development. If embryos were treated at the preglobular or globular stages of embryogenesis, they developed one fused cotyledon indicating a continuation of radial symmetry. However, if treated later in development, embryos were comparable to the control and formed two separate cotyledons. To demonstrate that this was not a pharmacological effect, an auxin antagonist, 2-(p-chlorophenoxy)-2-methylpropionic acid, included with the TIBA treatment produced normal embryos with two separate cotyledons. Histological observations revealed that the shoot apical meristem of the embryos treated with TIBA or IAA at the preglobular and globular stages was altered. Preglobular and globular stage embryos that were treated with TIBA exhibited a dramatic decline in conversion frequency compared with their controls. Embryos that were treated later in development had conversion frequencies comparable to their controls, and their shoot apical meristems also were similar to controls. Application of ABA at the preglobular and globular stages maintained meristem integrity and improved embryo conversion. However, ABA could not reverse the TIBA effect.

scholarly journals Arabidopsis Argonaute10 Specifically Sequesters miR166/165 to Regulate Shoot Apical Meristem Development

Cell ◽  
2011 ◽  
Vol 145 (2) ◽  
pp. 242-256 ◽  
Author(s):  
Hongliang Zhu ◽  
Fuqu Hu ◽  
Ronghui Wang ◽  
Xin Zhou ◽  
Sing-Hoi Sze ◽  
...  
Keyword(s):  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Meristem Development

PIN-FORMED 1 regulates cell fate at the periphery of the shoot apical meristem

Development ◽  
2000 ◽  
Vol 127 (23) ◽  
pp. 5157-5165 ◽  
Author(s):  
T. Vernoux ◽  
J. Kronenberger ◽  
O. Grandjean ◽  
P. Laufs ◽  
J. Traas
Keyword(s):  
Cell Fate ◽  
Apical Meristem ◽  
Transmembrane Protein ◽  
Loss Of Function ◽  
Hybrid Identity ◽  
Hormone Transport ◽  
Early Markers ◽  
Ideal Tool ◽  
And Function

The process of organ positioning has been addressed, using the pin-formed 1 (pin1) mutant as a tool. PIN1 is a transmembrane protein involved in auxin transport in Arabidopsis. Loss of function severely affects organ initiation, and pin1 mutants are characterised by an inflorescence meristem that does not initiate any flowers, resulting in the formation of a naked inflorescence stem. This phenotype, combined with the proposed role of PIN1 in hormone transport, makes the mutant an ideal tool to study organ formation and phyllotaxis, and here we present a detailed analysis of the molecular modifications at the shoot apex caused by the mutation. We show that meristem structure and function are not severely affected in the mutant. Major alterations, however, are observed at the periphery of the pin1 meristem, where organ initiation should occur. Although two very early markers of organ initiation, LEAFY and AINTEGUMENTA, are expressed at the periphery of the mutant meristem, the cells are not recruited into distinct primordia. Instead a ring-like domain expressing those primordium specific genes is observed around the meristem. This ring-like domain also expresses a boundary marker, CUP-SHAPED COTYLEDON 2, involved in organ separation, showing that the zone at the meristem periphery has a hybrid identity. This implies that PIN1 is not only involved in organ outgrowth, but that it is also necessary for organ separation and positioning. A model is presented in which PIN1 and the local distribution of auxin control phyllotaxis.

scholarly journals Irritable bowel syndrome: new insights into symptom mechanisms and advances in treatment

F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 780 ◽  
Author(s):  
Robin Spiller
Keyword(s):  
Irritable Bowel Syndrome ◽  
New Agents ◽  
Enteric Nerves ◽  
Inflammatory Bowel ◽  
Magnetic Resonance Imaging Mri ◽  
Irritable Bowel ◽  
Fodmap Diet ◽  
And Function ◽  
The Impact

Despite being one of the most common conditions leading to gastroenterological referral, irritable bowel syndrome (IBS) is poorly understood. However, recent years have seen major advances. These include new understanding of the role of both inflammation and altered microbiota as well as the impact of dietary intolerances as illuminated by magnetic resonance imaging (MRI), which has thrown new light on IBS. This article will review new data on how excessive bile acid secretion mediates diarrhea and evidence from post infectious IBS which has shown how gut inflammation can alter gut microbiota and function. Studies of patients with inflammatory bowel disease (IBD) have also shown that even when inflammation is in remission, the altered enteric nerves and abnormal microbiota can generate IBS-like symptoms. The efficacy of the low FODMAP diet as a treatment for bloating, flatulence, and abdominal discomfort has been demonstrated by randomized controlled trials. MRI studies, which can quantify intestinal volumes, have provided new insights into how FODMAPs cause symptoms. This article will focus on these areas together with recent trials of new agents, which this author believes will alter clinical practice within the foreseeable future.

scholarly journals Peran Pendidikan Etika Kristen dalam Media Sosial di Era Disrupsi

2020 ◽  
Vol 1 (1) ◽  
pp. 38-46
Author(s):  
Mesirawati Waruwu ◽  
Yonatan Alex Arifianto ◽  
Aji Suseno
Keyword(s):  
Social Media ◽  
Ethics Education ◽  
Christian Ethics ◽  
Christian Faith ◽  
Ethical Challenges ◽  
Use Of Social Media ◽  
And Function ◽  
Meaning And Function ◽  
The Impact

The limitless development of social media, its meaning and function have begun to shift, no longer as a means of establishing relationships, communication, but at the stage of losing the role of ethics and morals, even disputes have occurred triggered by debates from communicating in social media. The purpose of this study is to describe the role of Christian ethics education in relation to the impact of social media development in the era of disruption. Using descriptive qualitative methods with literature literature can find solutions for believers in facing moral decadence due to social media abuse by knowing the era of disruption and ethical challenges from the wrong use of social media can affect moral decadence so that Christian ethics education on a biblical basis can bring modern humans. Believers in particular have become bright in social media and their use in accordance with Christian faith in this era of disruption.

scholarly journals Agronomic Performance and Flowering Behavior in Response to Photoperiod and Vernalization in Barley (Hordeum vulgare L.) Genotypes with Contrasting Drought Tolerance Behavior

2021 ◽  
Author(s):  
Jamal Abu-Elenein ◽  
Rabea Al-Sayaydeh ◽  
Zahera Akkeh ◽  
Zakaria Al-Ajlouni ◽  
AbdRaheem A. Al-Bawalize ◽  
...  
Keyword(s):  
Drought Tolerance ◽  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Agronomic Performance ◽  
Short Day ◽  
Drought Tolerant ◽  
Long Day ◽  
Meristem Development ◽  
Rainfed Conditions ◽  
Barley Genotypes

Abstract Background In barley, flowering behavior is a highly regulated and complex process where the appropriate matching of reproductive development with seasonal variation in water availability confer barley adaptation to different environments. In this study, the role of variation in flowering time and drought tolerance in four selected barley genotypes was studied under field and controlled conditions. For this purpose, field trials were conducted for two consecutive seasons at three diverse environments where the studied genotypes were subjected to either rainfed conditions or rainfed plus supplementary irrigation under two different sowing dates. Furthermore, reproductive meristem development in two selected barley genotypes, Rum (drought tolerant) and Steptoe (drought-sensitive) was also assessed in response to both vernalization and water stress under two different photoperiod conditions.Results Variation in the number of days to heading was more pronounced under rainfed conditions than under well water conditions. For agronomic performance, Rum was superior under all tested environments, which assure its general adaptability to multiple environments, while Steptoe was the poorest. The transition to reproductive meristem was faster under vernalized long-day conditions as compared to vernalized short-day conditions. The progress of shoot apical meristem development and heading under long-day conditions was significantly faster in Rum than that of Steptoe. A clear effect of drought stress was observed on shoot apical meristem development in Steptoe. Under short-day conditions, vernalized Rum plants subjected to water deficit showed an advanced meristem development stage a significant earlier HD when compared with non-stressed plants. This early flowering behavior in stressed Rum plants under short-day conditions was accompanied by higher gene expression of the Vrn-H1 gene. Conclusion In conclusion, the integration of vernalization and photoperiod signals in drought-tolerant barley genotypes is associated with early flowering behavior and higher productivity in dry environments.

An altered body plan is conferred on Arabidopsis plants carrying dominant alleles of two genes

Development ◽  
1996 ◽  
Vol 122 (8) ◽  
pp. 2395-2403 ◽  
Author(s):  
B. Grbic ◽  
A.B. Bleecker
Keyword(s):  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Reproductive Development ◽  
Body Plan ◽  
Chromosome 4 ◽  
Chromosome 5 ◽  
Present Evidence ◽  
Primary Shoot ◽  
Axillary Meristems

In this paper, we describe a late-flowering ecotype of Arabidopsis, Sy-0, in which the axillary meristems maintain a prolonged vegetative phase, even though the primary shoot apical meristem has already converted to reproductive development. This novel heterochronic shift in the development of axillary meristems results in the formation of aerial rosettes of leaves at the nodes of the primary shoot axis. We present evidence that the aerial-rosette phenotype arises due to the interaction between dominant alleles of two genes: ART, aerial rosette gene (on chromosome 5) and EAR, enhancer of aerial rosette (on chromosome 4): EAR has been tentatively identified as a new allele of the FRI locus. The possible role of these two genes in the conversion of shoot apical meristems to reproductive development is discussed.

Characterisation of three shoot apical meristem mutants of Arabidopsis thaliana

Development ◽  
1992 ◽  
Vol 116 (2) ◽  
pp. 397-403 ◽  
Author(s):  
H. M. Ottoline Leyser ◽  
I. J. Furner
Keyword(s):  
Arabidopsis Thaliana ◽  
Root Growth ◽  
Shoot Apical Meristem ◽  
Apical Meristem ◽  
Floral Development ◽  
Wild Type ◽  
Recessive Mutations ◽  
Phenotypic Characterisation ◽  
Dicotyledonous Plants ◽  
And Function

The shoot apical meristem of dicotyledonous plants is highly regulated both structurally and functionally, but little is known about the mechanisms involved in this regulation. Here we describe the genetic and phenotypic characterisation of recessive mutations at three loci of Arabidopsis thaliana in which meristem structure and function are disrupted. The loci are Clavata1 (Clv1), Fasciata1 (Fas1) and Fasciata2 (Fas2). Plants mutant at these loci are fasciated having broad, flat stems and disrupted phyllotaxy. In all cases, the fasciations are associated with shoot apical meristem enlargement and altered floral development. While all the mutants share some phenotypic features they can be divided into two classes. The pleiotropic fas1 and fas2 mutants are unable to initiate wild- type organs, show major alterations in meristem structure and have reduced root growth. In contrast, clv1 mutant plants show near wild-type organ phenotypes, more subtle changes in shoot apical meristem structure and wild-type root growth.

scholarly journals Contribution of HIV Infection, AIDS, and Antiretroviral Therapy to Exocrine Pathogenesis in Salivary and Lacrimal Glands

2018 ◽  
Vol 19 (9) ◽  
pp. 2747 ◽  
Author(s):  
Imran Nizamuddin ◽  
Peter Koulen ◽  
Carole McArthur
Keyword(s):  
Antiretroviral Therapy ◽  
Hiv Infection ◽  
Immune Deficiency Syndrome ◽  
Deficiency Syndrome ◽  
Exocrine Function ◽  
Lacrimal Glands ◽  
Immunodeficiency Virus ◽  
And Function ◽  
The Impact

The structure and function of exocrine glands are negatively affected by human immunodeficiency virus (HIV) infection and its co-morbidities, including innate and adaptive immune responses. At the same time, exocrine function may also be influenced by pharmacotherapies directed at the infectious agents. Here, we briefly review the role of the salivary glands and lacrimal glands in normal physiology and exocrine pathogenesis within the context of HIV infection and acquired immune deficiency syndrome (AIDS), including the contribution of antiretroviral therapies on both. Subsequently, we discuss the impact of HIV infection and the types of antiretroviral therapy on disease management and therapy development efforts.

A stochastic roadmap method to model protein structural transitions

Robotica ◽  
2015 ◽  
Vol 34 (8) ◽  
pp. 1705-1733 ◽  
Author(s):  
Kevin Molloy ◽  
Rudy Clausen ◽  
Amarda Shehu
Keyword(s):  
Protein Structure ◽  
Molecular Basis ◽  
Structure And Function ◽  
Structural Transitions ◽  
Simulation Framework ◽  
Human Disorders ◽  
Model Protein ◽  
And Function ◽  
The Impact

SUMMARYEvidence is emerging that the role of protein structure in disease needs to be rethought. Sequence mutations in proteins are often found to affect the rate at which a protein switches between structures. Modeling structural transitions in wildtype and variant proteins is central to understanding the molecular basis of disease. This paper investigates an efficient algorithmic realization of the stochastic roadmap simulation framework to model structural transitions in wildtype and variants of proteins implicated in human disorders. Our results indicate that the algorithm is able to extract useful information on the impact of mutations on protein structure and function.

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