scholarly journals MEDIATOR18 influences Arabidopsis root architecture, represses auxin signaling and is a critical factor for cell viability in root meristems

2018 ◽  
Vol 96 (5) ◽  
pp. 895-909 ◽  
Author(s):  
Javier Raya-González ◽  
Araceli Oropeza-Aburto ◽  
Jesús S. López-Bucio ◽  
Ángel A. Guevara-García ◽  
Lieven de Veylder ◽  
...  
Keyword(s):  
Cell Viability ◽  
Root Architecture ◽  
Critical Factor ◽  
Auxin Signaling ◽  
Arabidopsis Root ◽  
Root Meristems

scholarly journals Glutamate signalling via a MEKK1 kinase-dependent pathway induces changes in Arabidopsis root architecture

2013 ◽  
Vol 75 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Brian G. Forde ◽  
Sean R. Cutler ◽  
Najia Zaman ◽  
Patrick J. Krysan
Keyword(s):  
Root Architecture ◽  
Arabidopsis Root ◽  
Dependent Pathway

scholarly journals Auxin requirements for a meristematic state in roots depend on a dual brassinosteroid function

2020 ◽  
Author(s):  
M. Ackerman-Lavert ◽  
Y. Fridman ◽  
R Matosevich ◽  
H Khandal ◽  
L. Friedlander ◽  
...  
Keyword(s):  
Signaling Pathways ◽  
Auxin Biosynthesis ◽  
Auxin Signaling ◽  
Critical Ratio ◽  
Dual Effect ◽  
Normal Morphology ◽  
Arabidopsis Root ◽  
Auxin Synthesis ◽  
Meristem Maintenance ◽  
Transcriptional Output

SummaryThe organization of the root meristem is maintained by a complex interplay between plant hormones signaling pathways that both interpret and determine their accumulation and distribution. Brassinosteroids (BR) and auxin signaling pathways control the number of meristematic cells in the Arabidopsis root, via an interaction that appears to involve contradicting molecular outcomes, with BR promoting auxin signaling input but also repressing its output. However, whether this seemingly incoherent effect is significant for meristem function is unclear. Here, we established that a dual effect of BR on auxin, with BR simultaneously promoting auxin biosynthesis and repressing auxin transcriptional output, is essential for meristem maintenance. Blocking BR-induced auxin synthesis resulted in rapid BR-mediated meristem loss. Conversely, plants with reduced BR levels were resistant to loss of auxin biosynthesis and these meristems maintained their normal morphology despite a 10-fold decrease in auxin levels. In agreement, injured root meristems which rely solely on local auxin synthesis, regenerated when both auxin and BR synthesis were inhibited. Use of BIN2 as a tool to selectively inhibit BR signaling, revealed meristems with distinct phenotypes depending on the perturbed tissue; meristem reminiscent of BR-deficient mutants or of high BR exposure. This enabled mapping BR-auxin interactions to the outer epidermis and lateral root cap tissues, and demonstrated the essentiality of BR signaling in these tissues for meristem maintenance. BR activity in internal tissues however, proved necessary to control BR homeostasis. Together, we demonstrate a basis for inter-tissue coordination and how a critical ratio between these hormones determines the meristematic state.

scholarly journals Overexpression of the Auxin Receptor AFB3 in Arabidopsis Results in Salt Stress Resistance and the Modulation of NAC4 and SZF1

2020 ◽  
Vol 21 (24) ◽  
pp. 9528
Author(s):  
Fernanda Garrido-Vargas ◽  
Tamara Godoy ◽  
Ricardo Tejos ◽  
José Antonio O’Brien
Keyword(s):  
Salt Stress ◽  
Stress Response ◽  
Growth And Development ◽  
Root Architecture ◽  
Crop Production ◽  
Lateral Roots ◽  
Auxin Signaling ◽  
Auxin Receptor ◽  
Salt Stress Response ◽  
Regulatory Pathways

Soil salinity is a key problem for crop production worldwide. High salt concentration in soil negatively modulates plant growth and development. In roots, salinity affects the growth and development of both primary and lateral roots. The phytohormone auxin regulates various developmental processes during the plant’s life cycle, including several aspects of root architecture. Auxin signaling involves the perception by specialized receptors which module several regulatory pathways. Despite their redundancy, previous studies have shown that their functions can also be context-specific depending on tissue, developmental or environmental cues. Here we show that the over-expression of Auxin Signaling F-Box 3 receptor results in an increased resistance to salinity in terms of root architecture and germination. We also studied possible downstream signaling components to further characterize the role of auxin in response to salt stress. We identify the transcription factor SZF1 as a key component in auxin-dependent salt stress response through the regulation of NAC4. These results give lights of an auxin-dependent mechanism that leads to the modulation of root system architecture in response to salt identifying a hormonal cascade important for stress response.

scholarly journals Salt Stress Affects the Redox Status of Arabidopsis Root Meristems

2016 ◽  
Vol 7 ◽  
Author(s):  
Keni Jiang ◽  
Jacob Moe-Lange ◽  
Lauriane Hennet ◽  
Lewis J. Feldman
Keyword(s):  
Salt Stress ◽  
Redox Status ◽  
Arabidopsis Root ◽  
Root Meristems

Melatonin regulates Arabidopsis root system architecture likely acting independently of auxin signaling

2012 ◽  
Vol 53 (3) ◽  
pp. 279-288 ◽  
Author(s):  
Ramón Pelagio-Flores ◽  
Edith Muñoz-Parra ◽  
Randy Ortiz-Castro ◽  
José López-Bucio
Keyword(s):  
Root System ◽  
System Architecture ◽  
Root System Architecture ◽  
Auxin Signaling ◽  
Arabidopsis Root

scholarly journals Differential Cytotoxicity of Different Sizes of Graphene Oxide Nanoparticles in Leydig (TM3) and Sertoli (TM4) Cells

Nanomaterials ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 139 ◽  
Author(s):  
Sangiliyandi Gurunathan ◽  
Min-Hee Kang ◽  
Muniyandi Jeyaraj ◽  
Jin-Hoi Kim
Keyword(s):  
Graphene Oxide ◽  
Cell Viability ◽  
Graphene Nanosheets ◽  
Critical Factor ◽  
Biological Properties ◽  
Significant Loss ◽  
Toxic Effects ◽  
Biological Behavior ◽  
Ros Generation ◽  
Size Dependent

Graphene oxide (GO) is an common nanomaterial and has attracted unlimited interest in academia and industry due to its physical, chemical, and biological properties, as well as for its tremendous potential in applications in various fields, including nanomedicine. Whereas studies have evaluated the size-dependent cytotoxicity of GO in cancer cells, there have been no studies on the biological behavior of ultra-small graphene nanosheets in germ cells. To investigate, for the first time, the cyto- and geno- toxic effects of different sizes of GO in two different cell types, Leydig (TM3) and Sertoli (TM4) cells, we synthesized different sized GO nanosheets with an average size of 100 and 20 nm by a modification of Hummers’ method, and characterized them by various analytical techniques. Cell viability and proliferation assays showed significant size- and dose-dependent toxicity with GO-20 and GO-100. Interestingly, GO-20 induced significant loss of cell viability and cell proliferation, higher levels of leakage of lactate dehydrogenase (LDH) and reactive oxygen species (ROS) generation compared to GO-100. Both GO-100 and GO-20 induced significant loss of mitochondrial membrane potential (MMP) in TM3 and TM4 cells, which is a critical factor for ROS generation. Furthermore, GO-100 and GO-20 caused oxidative damage to DNA by increasing the levels of 8-oxo-dG, which is formed by direct attack of ROS on DNA; GO-100 and GO-20 upregulate various genes responsible for DNA damage and apoptosis. We found that phosphorylation levels of EGFR/AKT signaling molecules, which are related to cell survival and apoptosis, were significantly altered after GO-100 and GO-20 exposure. Our results showed that GO-20 has more potent toxic effects than GO-100, and that the loss of MMP and apoptosis are the main toxicity responses to GO-100 and GO-20 treatments, which likely occur due to EGFR/AKT pathway regulation. Collectively, our results suggest that both GO-100 and GO-20 exhibit size-dependent germ cell toxicity in male somatic cells, particularly TM3 cells, which seem to be more sensitive compared to TM4, which strongly suggests that applications of GO in commercial products must be carefully evaluated.

scholarly journals Endogenous Hypoxia in Lateral Root Primordia Controls Root Architecture by Antagonizing Auxin Signaling in Arabidopsis

2019 ◽  
Vol 12 (4) ◽  
pp. 538-551 ◽  
Author(s):  
Vinay Shukla ◽  
Lara Lombardi ◽  
Sergio Iacopino ◽  
Ales Pencik ◽  
Ondrej Novak ◽  
...  
Keyword(s):  
Lateral Root ◽  
Root Architecture ◽  
Auxin Signaling ◽  
Root Primordia ◽  
Lateral Root Primordia

scholarly journals Overexpression of OsPT8 Increases Auxin Content and Enhances Tolerance to High-Temperature Stress in Nicotiana tabacum

Genes ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 809 ◽  
Author(s):  
Song ◽  
Fan ◽  
Jiao ◽  
Liu ◽  
Wang ◽  
...  
Keyword(s):  
High Temperature ◽  
Temperature Stress ◽  
Root Architecture ◽  
Molecular Mechanisms ◽  
Extreme Temperature ◽  
High Temperature Stress ◽  
Wild Plants ◽  
Auxin Signaling ◽  
Plant Tolerance ◽  
Auxin Content

Temperature is a primary factor affecting the rate of plant development; as the climate warms, extreme temperature events are likely to increasingly affect agriculture. Understanding how to improve crop tolerance to heat stress is a key concern. Wild plants have evolved numerous strategies to tolerate environmental conditions, notably the regulation of root architecture by phytohormones, but the molecular mechanisms of stress resistance are unclear. In this study, we showed that high temperatures could significantly reduce tobacco biomass and change its root architecture, probably through changes in auxin content and distribution. Overexpression of the OsPT8 phosphate transporter enhanced tobacco tolerance to high-temperature stress by changing the root architecture and increased the antioxidant ability. Molecular assays suggested that overexpression of OsPT8 in tobacco significantly increased the expression of auxin synthesis genes NtYUCCA 6, 8 and auxin efflux carriers genes NtPIN 1,2 under high-temperature stress. We also found that the expression levels of auxin response factors NtARF1 and NtARF2 were increased in OsPT8 transgenic tobacco under high-temperature stress, suggesting that OsPT8 regulates auxin signaling in response to high-temperature conditions. Our findings provided new insights into the molecular mechanisms of plant stress signaling and showed that OsPT8 plays a key role in regulating plant tolerance to stress conditions.

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