scholarly journals Photoreceptors Regulate Plant Developmental Plasticity through Auxin

Plants ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 940 ◽  
Author(s):  
Jesse J. Küpers ◽  
Lisa Oskam ◽  
Ronald Pierik
Keyword(s):  
Developmental Plasticity ◽  
Auxin Transport ◽  
Green Light ◽  
Direct Interaction ◽  
Target Cells ◽  
Resistance Locus ◽  
Long Distance ◽  
Response Factors ◽  
Auxin Response Factors ◽  
Auxin Signalling

Light absorption by plants changes the composition of light inside vegetation. Blue (B) and red (R) light are used for photosynthesis whereas far-red (FR) and green light are reflected. A combination of UV-B, blue and R:FR-responsive photoreceptors collectively measures the light and temperature environment and adjusts plant development accordingly. This developmental plasticity to photoreceptor signals is largely regulated through the phytohormone auxin. The phytochrome, cryptochrome and UV Resistance Locus 8 (UVR8) photoreceptors are inactivated in shade and/or elevated temperature, which releases their repression of Phytochrome Interacting Factor (PIF) transcription factors. Active PIFs stimulate auxin synthesis and reinforce auxin signalling responses through direct interaction with Auxin Response Factors (ARFs). It was recently discovered that shade-induced hypocotyl elongation and petiole hyponasty depend on long-distance auxin transport towards target cells from the cotyledon and leaf tip, respectively. Other responses, such as phototropic bending, are regulated by auxin transport and signalling across only a few cell layers. In addition, photoreceptors can directly interact with components in the auxin signalling pathway, such as Auxin/Indole Acetic Acids (AUX/IAAs) and ARFs. Here we will discuss the complex interactions between photoreceptor and auxin signalling, addressing both mechanisms and consequences of these highly interconnected pathways.

scholarly journals TRIM22. A Multitasking Antiviral Factor

Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1864
Author(s):  
Isabel Pagani ◽  
Guido Poli ◽  
Elisa Vicenzi
Keyword(s):  
Protein Interactions ◽  
Influenza A ◽  
Direct Interaction ◽  
Type I Interferons ◽  
Viral Gene ◽  
Target Cells ◽  
Type I ◽  
Protein Protein Interactions ◽  
Viral Genomes ◽  
Dna And Rna

Viral invasion of target cells triggers an immediate intracellular host defense system aimed at preventing further propagation of the virus. Viral genomes or early products of viral replication are sensed by a number of pattern recognition receptors, leading to the synthesis and production of type I interferons (IFNs) that, in turn, activate a cascade of IFN-stimulated genes (ISGs) with antiviral functions. Among these, several members of the tripartite motif (TRIM) family are antiviral executors. This article will focus, in particular, on TRIM22 as an example of a multitarget antiviral member of the TRIM family. The antiviral activities of TRIM22 against different DNA and RNA viruses, particularly human immunodeficiency virus type 1 (HIV-1) and influenza A virus (IAV), will be discussed. TRIM22 restriction of virus replication can involve either direct interaction of TRIM22 E3 ubiquitin ligase activity with viral proteins, or indirect protein–protein interactions resulting in control of viral gene transcription, but also epigenetic effects exerted at the chromatin level.

scholarly journals Role of auxin homeostasis and response in nitrogen limitation and dark stimulation of adventitious root formation in petunia cuttings

2019 ◽  
Vol 124 (6) ◽  
pp. 1053-1066 ◽  
Author(s):  
Huaiyu Yang ◽  
Yvonne Klopotek ◽  
Mohammad R Hajirezaei ◽  
Siegfried Zerche ◽  
Philipp Franken ◽  
...  
Keyword(s):  
Nitrogen Limitation ◽  
Auxin Transport ◽  
Polar Auxin Transport ◽  
Auxin Homeostasis ◽  
Stem Base ◽  
Auxin Signalling ◽  
Dark Exposure ◽  
Rna Accumulation ◽  
Low Nitrogen ◽  
Stimulation Of

Abstract Background and Aims Adventitious root (AR) formation in Petunia hybrida is inhibited by low nitrogen fertilization of stock plants but promoted by dark incubation of cuttings before planting. We investigated whether the plant hormone auxin is involved in nitrogen- and dark-mediated AR formation. Methods Concentrations of indole-3-acetic acid (IAA) and RNA accumulation of genes controlling auxin homeostasis and function were monitored in the stem base in response to high versus low nitrogen supply to stock plants and to temporal dark vs. light exposure of cuttings by use of GC-MS/MS, a petunia-specific microarray and quantitative RT-PCR. Auxin source capacity, polar auxin transport in cuttings and auxin concentration in the rooting zone were manipulated to investigate the functional contribution of auxin homeostasis and response to the effects of nitrogen fertilization and dark exposure on rooting. Key Results The nitrogen content of cuttings had only a marginal effect on IAA concentration in the stem base. Dark incubation enhanced the accumulation of IAA in the stem base during AR induction independent of nitrogen level. Early IAA accumulation in the dark depended on the upper shoot as an auxin source and was enhanced after apical IAA supply. Dark exposure stimulated RNA accumulation of auxin-related genes. In particular, expression of Ph-PIN1 and of genes controlling auxin signalling, including Ph-IAA14, Ph-ARF8, Ph-ARF10 and Ph-SAUR14, was enhanced, while the latter four were repressed in nitrogen-limited cuttings, particularly in the dark. Dark stimulation of rooting depended on polar auxin transport. Basal auxin application partially substituted the effect of dark exposure on rooting, whereas the auxin response of AR formation was strongly depressed by nitrogen limitation. Conclusions Increased auxin delivery from the upper shoot and enhanced auxin signalling in the stem base contribute to dark-stimulated AR formation, while nitrogen limitation inhibits AR formation downstream of the auxin signal.

scholarly journals Parallel structural evolution of auxin response factors in the angiosperms

2010 ◽  
Vol 63 (6) ◽  
pp. 952-959 ◽  
Author(s):  
Cédric Finet ◽  
Chloé Fourquin ◽  
Marion Vinauger ◽  
Annick Berne-Dedieu ◽  
Pierre Chambrier ◽  
...  
Keyword(s):  
Structural Evolution ◽  
Auxin Response ◽  
Response Factors ◽  
Auxin Response Factors

scholarly journals Noncoding RNAs, Emerging Regulators in Root Endosymbioses

2016 ◽  
Vol 29 (3) ◽  
pp. 170-180 ◽  
Author(s):  
Christine Lelandais-Brière ◽  
Jérémy Moreau ◽  
Caroline Hartmann ◽  
Martin Crespi
Keyword(s):  
Gene Expression ◽  
Regulatory Networks ◽  
Plant Root ◽  
Arbuscular Mycorrhizal ◽  
Auxin Response ◽  
Response Factors ◽  
Auxin Response Factors ◽  
Control Gene Expression ◽  
Small Ncrnas ◽  
Am Symbiosis

Endosymbiosis interactions allow plants to grow in nutrient-deficient soil environments. The arbuscular mycorrhizal (AM) symbiosis is an ancestral interaction between land plants and fungi, whereas nitrogen-fixing symbioses are highly specific for certain plants, notably major crop legumes. The signaling pathways triggered by specific lipochitooligosaccharide molecules involved in these interactions have common components that also overlap with plant root development. These pathways include receptor-like kinases, transcription factors (TFs), and various intermediate signaling effectors, including noncoding (nc)RNAs. These latter molecules have emerged as major regulators of gene expression and small ncRNAs, composed of micro (mi)RNAs and small interfering (si)RNAs, are known to control gene expression at transcriptional (chromatin) or posttranscriptional levels. In this review, we describe exciting recent data connecting variants of conserved si/miRNAs with the regulation of TFs, such as NSP2, NFY-A1, auxin-response factors, and AP2-like proteins, known to be involved in symbiosis. The link between hormonal regulations and these si- and miRNA-TF nodes is proposed in a model in which different feedback loops or regulations controlling endosymbiosis signaling are integrated. The diversity and emerging regulatory networks of young legume miRNAs are also highlighted.

Regulation of Nodule Development by Short- and Long-Distance Auxin Transport Control

2015 ◽  
pp. 465-474 ◽  
Author(s):  
Ulrike Mathesius ◽  
Jian Jin ◽  
Giel E. Noorden ◽  
Liang P. J. Ng ◽  
Anton P. Wasson
Keyword(s):  
Auxin Transport ◽  
Nodule Development ◽  
Long Distance ◽  
Transport Control

Corrigendum to: Auxin is required for pollination-induced ovary growth in Dendrobium orchids

2006 ◽  
Vol 33 (10) ◽  
pp. 981 ◽  
Author(s):  
Saichol Ketsa ◽  
Apinya Wisutiamonkul ◽  
Wouter G. van Doorn
Keyword(s):  
Auxin Transport ◽  
Isobutyric Acid ◽  
Signalling Pathway ◽  
Aminooxyacetic Acid ◽  
Ethylene Synthesis ◽  
Transport Inhibitor ◽  
Auxin Signalling ◽  
Auxin Transport Inhibitor ◽  
Ethylene Action ◽  
Ovary Growth

In Dendrobium and other orchids the ovule becomes mature long after pollination, whereas the ovary starts growing within two days of pollination. The signalling pathway that induces rapid ovary growth after pollination has remained elusive. We placed the auxin antagonist �-(p-chlorophenoxy) isobutyric acid (PCIB) or the auxin transport inhibitor 2,3,5-triiodobenzoic acid (TIBA) on the stigma, before pollination. Both treatments nullified pollination-induced ovary growth. The ovaries also did not grow after similar stigma treatment with 1-methylcyclopropene (1-MCP), AgNO3 (both inhibitors of ethylene action), aminooxyacetic acid (AOA) or CoCl2 (which both inhibit ethylene synthesis), before pollination. Pollination could be replaced by placement of the auxin naphthylacetic acid (NAA) on the stigma. All mentioned inhibitors nullified the effect of NAA, indicating that if auxin is the initiator of ovary growth, it acts through ethylene. The results suggest that the pollination effect on ovary growth requires auxin (at least auxin transport and maybe also auxin signalling), and both ethylene synthesis and ethylene action.

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