scholarly journals MicroRNA840 accelerates leaf senescence by targeting the overlapping 3’UTRs of PPR and WHIRLY3 in Arabidopsis thaliana

2020 ◽  
Author(s):  
Ren Yujun ◽  
Wang Wanzhen ◽  
Lan Wei ◽  
Schenke Dirk ◽  
Cai Daguang ◽  
...  
Keyword(s):  
Stress Responses ◽  
Transcript Level ◽  
Transcriptional Gene Silencing ◽  
Loss Of Function ◽  
Knockout Mutant ◽  
Plant Senescence ◽  
Senescent Phenotype ◽  
Post Transcriptional Gene Silencing

AbstractMicroRNAs (miRNAs) negatively regulate gene expression by cleaving the target mRNA and/or impairing its translation, thereby playing a crucial role in plant development and environmental stress responses. In Arabidopsis, MIR840 is located within the overlapping 3’UTR of PPR and WHIRLY3 (WHY3), both being predicted targets of miR840. Gain- and loss-of-function of miR840 in Arabidopsis resulted in opposite senescent phenotypes. Highest expression of pri-miR840 is observed at senescence initiation, and is negatively correlated with a significant reduction of PPR transcripts but not of WHY3. Although WHY3 transcript levels were not significantly affected by miR840 overexpression, its protein synthesis was strongly reduced. Mutating the cleavage sites or replacing the target sequences abolishes the miR840-mediated degradation of PPR transcripts and inhibition of WHY3 translation. In support for this, concurrent knock-down of both PPR and WHY3 in the WT resulted in the senescent phenotype resembling that of the miR840-overexpressing mutant. This indicates that both PRR and WHY3 are targets in the miR840-regulated senescent pathway. Moreover, single knockout mutant of PPR or WHY3 shows a convergent up-regulated subset of senescence-associated genes, which are also found among those induced by miR840 overexpression. Our data provide evidences for a regulatory role of miR840 in plant senescence.HighlightMicroRNA840 (miR840) has a unique miRNA-target configuration regulating PPR and WHIRLY3 genes in Arabidopsis. MiR840 is highly expressed at the onset of plant senescent stage. Both PPR and WHIRLY3 transcripts are specifically targeted in vivo within their 3’UTR region by mature miR840 or its star strand in vivo. Interestingly, PPR expression is mainly repressed on mRNA transcript level by cleavage, while WHIRLY3 is predominantly translationally inhibited. We conclude that miR840 enhances plant senescence via post transcriptional gene silencing of PPR and WHIRLY3, which appear to be novel negative joint regulators of plant senescence.Footnote: The author(s) responsible for distribution of materials integral to the findings presented in this article in accordance with the policy described in the intructions for Authors is: Ying Miao ([email protected])

scholarly journals MicroRNAs: Potential Targets for Developing Stress-Tolerant Crops

Life ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 289
Author(s):  
Saurabh Chaudhary ◽  
Atul Grover ◽  
Prakash Chand Sharma
Keyword(s):  
Stress Responses ◽  
Functional Role ◽  
Agronomic Traits ◽  
Climatic Conditions ◽  
Transcriptional Gene Silencing ◽  
Plant Responses ◽  
Biotic Stresses ◽  
Crop Varieties ◽  
Post Transcriptional Gene Silencing

Crop yield is challenged every year worldwide by changing climatic conditions. The forecasted climatic scenario urgently demands stress-tolerant crop varieties to feed the ever-increasing global population. Molecular breeding and genetic engineering approaches have been frequently exploited for developing crops with desired agronomic traits. Recently, microRNAs (miRNAs) have emerged as powerful molecules, which potentially serve as expression markers during stress conditions. The miRNAs are small non-coding endogenous RNAs, usually 20–24 nucleotides long, which mediate post-transcriptional gene silencing and fine-tune the regulation of many abiotic- and biotic-stress responsive genes in plants. The miRNAs usually function by specifically pairing with the target mRNAs, inducing their cleavage or repressing their translation. This review focuses on the exploration of the functional role of miRNAs in regulating plant responses to abiotic and biotic stresses. Moreover, a methodology is also discussed to mine stress-responsive miRNAs from the enormous amount of transcriptome data available in the public domain generated using next-generation sequencing (NGS). Considering the functional role of miRNAs in mediating stress responses, these molecules may be explored as novel targets for engineering stress-tolerant crop varieties.

scholarly journals The AtHB1 Transcription Factor Controls the miR164-CUC2 Regulatory Node to Modulate Leaf Development

2019 ◽  
Vol 61 (3) ◽  
pp. 659-670 ◽  
Author(s):  
Virginia N Miguel ◽  
Pablo A Manavella ◽  
Raquel L Chan ◽  
Mat�as Capella
Keyword(s):  
Transcription Factor ◽  
Leucine Zipper ◽  
Micro Rna ◽  
Transcriptional Gene Silencing ◽  
Promoter Regions ◽  
Post Transcriptional Gene Silencing ◽  
Rna Genes ◽  
Nac Family

Abstract The presence of small tooth-like indentations, or serrations, characterizes leaf margins of Arabidopsis thaliana plants. The NAC family member CUP-SHAPED COTYLEDON 2 (CUC2), which undergoes post-transcriptional gene silencing by three micro-RNA genes (MIR164A, B and C), controls the extension of leaf serration. Here, we analyzed the role of AtHB1, a transcription factor (TF) belonging to the homeodomain-leucine zipper subfamily I, in shaping leaf margins. Using mutants with an impaired silencing pathway as background, we obtained transgenic plants expressing AtHB1 over 100 times compared to controls. These plants presented an atypical developmental phenotype characterized by leaves with deep serration. Transcript measurements revealed that CUC2 expression was induced in plants overexpressing AtHB1 and repressed in athb1 mutants, indicating a positive regulation exerted by this TF. Moreover, molecular analyses of AtHB1 overexpressing and mutant plants revealed that AtHB1 represses MIR164 transcription. We found that overexpression of MIR164B was able to reverse the serration phenotype of plants overexpressing AtHB1. Finally, chromatin immunoprecipitation assays revealed that AtHB1 was able to bind in vivo the promoter regions of all three MIR164 encoding loci. Altogether, our results indicate that AtHB1 directly represses MIR164 expression to enhance leaf serration by increasing CUC2 levels.

scholarly journals Viroids as a Tool to Study RNA-Directed DNA Methylation in Plants

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1187
Author(s):  
Michael Wassenegger ◽  
Athanasios Dalakouras
Keyword(s):  
Dna Methylation ◽  
Rna Interference ◽  
Gene Silencing ◽  
Plant Cells ◽  
Transcriptional Gene Silencing ◽  
Rnai Machinery ◽  
Double Stranded Rna ◽  
Post Transcriptional Gene Silencing ◽  
Cumulative Amount

Viroids are plant pathogenic, circular, non-coding, single-stranded RNAs (ssRNAs). Members of the Pospiviroidae family replicate in the nucleus of plant cells through double-stranded RNA (dsRNA) intermediates, thus triggering the host’s RNA interference (RNAi) machinery. In plants, the two RNAi pillars are Post-Transcriptional Gene Silencing (PTGS) and RNA-directed DNA Methylation (RdDM), and the latter has the potential to trigger Transcriptional Gene Silencing (TGS). Over the last three decades, the employment of viroid-based systems has immensely contributed to our understanding of both of these RNAi facets. In this review, we highlight the role of Pospiviroidae in the discovery of RdDM, expound the gradual elucidation through the years of the diverse array of RdDM’s mechanistic details and propose a revised RdDM model based on the cumulative amount of evidence from viroid and non-viroid systems.

scholarly journals MicroRNAs in Cardiac Autophagy: Small Molecules and Big Role

Cells ◽  
2018 ◽  
Vol 7 (8) ◽  
pp. 104 ◽  
Author(s):  
Teng Sun ◽  
Meng-Yang Li ◽  
Pei-Feng Li ◽  
Ji-Min Cao
Keyword(s):  
Cardiac Fibrosis ◽  
Heart Diseases ◽  
Critical Role ◽  
Transcriptional Gene Silencing ◽  
Close Link ◽  
Post Transcriptional Gene Silencing ◽  
Evolutionarily Conserved ◽  
Cardiac Disorders ◽  
Cellular Components

Autophagy, which is an evolutionarily conserved process according to the lysosomal degradation of cellular components, plays a critical role in maintaining cell homeostasis. Autophagy and mitochondria autophagy (mitophagy) contribute to the preservation of cardiac homeostasis in physiological settings. However, impaired or excessive autophagy is related to a variety of diseases. Recently, a close link between autophagy and cardiac disorders, including myocardial infarction, cardiac hypertrophy, cardiomyopathy, cardiac fibrosis, and heart failure, has been demonstrated. MicroRNAs (miRNAs) are a class of small non-coding RNAs with a length of approximately 21–22 nucleotides (nt), which are distributed widely in viruses, plants, protists, and animals. They function in mediating the post-transcriptional gene silencing. A growing number of studies have demonstrated that miRNAs regulate cardiac autophagy by suppressing the expression of autophagy-related genes in a targeted manner, which are involved in the pathogenesis of heart diseases. This review summarizes the role of microRNAs in cardiac autophagy and related cardiac disorders. Furthermore, we mainly focused on the autophagy regulation pathways, which consisted of miRNAs and their targeted genes.

scholarly journals Comparative reactions of recombinant papaya ringspot viruses with chimeric coat protein (CP) genes and wild-type viruses on CP-transgenic papaya

2001 ◽  
Vol 82 (11) ◽  
pp. 2827-2836 ◽  
Author(s):  
Chu-Hui Chiang ◽  
Ju-Jung Wang ◽  
Fuh-Jyh Jan ◽  
Shyi-Dong Yeh ◽  
Dennis Gonsalves
Keyword(s):  
Coat Protein ◽  
Sequence Similarity ◽  
Transcriptional Gene Silencing ◽  
Papaya Ringspot Virus ◽  
Wild Type ◽  
Coding Region ◽  
Transgenic Papaya ◽  
Cp Gene ◽  
Post Transcriptional Gene Silencing

Transgenic papaya cultivars SunUp and Rainbow express the coat protein (CP) gene of the mild mutant of papaya ringspot virus (PRSV) HA. Both cultivars are resistant to PRSV HA and other Hawaii isolates through homology-dependent resistance via post-transcriptional gene silencing. However, Rainbow, which is hemizygous for the CP gene, is susceptible to PRSV isolates from outside Hawaii, while the CP-homozygous SunUp is resistant to most isolates but susceptible to the YK isolate from Taiwan. To investigate the role of CP sequence similarity in overcoming the resistance of Rainbow, PRSV HA recombinants with various CP segments of the YK isolate were constructed and evaluated on Rainbow, SunUp and non-transgenic papaya. Non-transgenic papaya were severely infected by all recombinants, but Rainbow plants developed a variety of symptoms. On Rainbow, a recombinant with the entire CP gene of YK caused severe symptoms, while recombinants with only partial YK CP sequences produced a range of milder symptoms. Interestingly, a recombinant with a YK segment from the 5′ region of the CP gene caused very mild, transient symptoms, whereas recombinants with YK segments from the middle and 3′ parts of the CP gene caused prominent and lasting symptoms. SunUp was resistant to all but two recombinants, which contained the entire CP gene or the central and 3′-end regions of the CP gene and the 3′ non-coding region of YK, and the resulting symptoms were mild. It is concluded that the position of the heterologous sequences in the recombinants influences their pathogenicity on Rainbow.

scholarly journals An atypical class of non-coding small RNAs produced in rice leaves upon bacterial infection

2021 ◽  
Author(s):  
Ganna Reshetnyak ◽  
Jonathan M. Jacobs ◽  
Florence Auguy ◽  
Coline Sciallano ◽  
Lisa Claude ◽  
...  
Keyword(s):  
Gene Silencing ◽  
Stress Responses ◽  
Small Rnas ◽  
Early Stage ◽  
Kinase Domain ◽  
Transcriptional Gene Silencing ◽  
Small Interfering Rnas ◽  
Post Transcriptional Gene Silencing ◽  
Virulent Strains ◽  
Microbe Interactions

ABSTRACTNon-coding small RNAs (sRNA) act as mediators of gene silencing and regulate plant growth, development and stress responses. Early insights into plant sRNAs established a role in antiviral defense and they are now extensively studied across plant-microbe interactions. Here, sRNA sequencing discovered a class of sRNA in rice (Oryza sativa) specifically associated with foliar diseases caused by Xanthomonas oryzae bacteria. Xanthomonas-induced small RNAs (xisRNAs) loci were distinctively upregulated in response to diverse virulent strains at an early stage of infection producing a single duplex of 20-22nt sRNAs. xisRNAs production was dependent on the Type III secretion system, a major bacterial virulence factor for host colonization. xisRNA loci overlap with annotated transcripts sequences often encoding protein kinase domain proteins. A number of the corresponding rice cis-genes have documented functions in immune signaling and some xisRNA loci coincide with the coding sequence of a conserved kinase motif. xisRNAs exhibit features of small interfering RNAs and their biosynthesis depend on canonical components OsDCL1 and OsHEN1. xisRNA induction possibly mediates post-transcriptional gene silencing but they do not broadly suppress cis-genes expression on the basis of mRNA-seq data. Overall, our results identify a group of unusual sRNAs with a potential role in plant-microbe interactions.

Role of inverted DNA repeats in transcriptional and post-transcriptional gene silencing

2000 ◽  
pp. 123-140 ◽  
Author(s):  
Mariëlle W. M. Muskens ◽  
Adriënne P. A. Vissers ◽  
Joseph N. M. Mol ◽  
Jan M. Kooter
Keyword(s):  
Gene Silencing ◽  
Transcriptional Gene Silencing ◽  
Dna Repeats ◽  
Post Transcriptional Gene Silencing

scholarly journals Dynamic measurement of cytosolic pH and [NO3−] uncovers the role of the vacuolar transporter AtCLCa in cytosolic pH homeostasis

2020 ◽  
Vol 117 (26) ◽  
pp. 15343-15353 ◽  
Author(s):  
Elsa Demes ◽  
Laetitia Besse ◽  
Paloma Cubero-Font ◽  
Béatrice Satiat-Jeunemaitre ◽  
Sébastien Thomine ◽  
...  
Keyword(s):  
Chloride Channel ◽  
Loss Of Function ◽  
Ion Transporters ◽  
Ph Homeostasis ◽  
Cytosolic Ph ◽  
Cellular Processes ◽  
Plasma Membrane Proton Pump ◽  
Cytosolic Acidification

Ion transporters are key players of cellular processes. The mechanistic properties of ion transporters have been well elucidated by biophysical methods. Meanwhile, the understanding of their exact functions in cellular homeostasis is limited by the difficulty of monitoring their activity in vivo. The development of biosensors to track subtle changes in intracellular parameters provides invaluable tools to tackle this challenging issue. AtCLCa (Arabidopsis thalianaChloride Channel a) is a vacuolar NO3−/H+exchanger regulating stomata aperture inA.thaliana. Here, we used a genetically encoded biosensor, ClopHensor, reporting the dynamics of cytosolic anion concentration and pH to monitor the activity of AtCLCa in vivo inArabidopsisguard cells. We first found that ClopHensor is not only a Cl−but also, an NO3−sensor. We were then able to quantify the variations of NO3−and pH in the cytosol. Our data showed that AtCLCa activity modifies cytosolic pH and NO3−. In an AtCLCa loss of function mutant, the cytosolic acidification triggered by extracellular NO3−and the recovery of pH upon treatment with fusicoccin (a fungal toxin that activates the plasma membrane proton pump) are impaired, demonstrating that the transport activity of this vacuolar exchanger has a profound impact on cytosolic homeostasis. This opens a perspective on the function of intracellular transporters of the Chloride Channel (CLC) family in eukaryotes: not only controlling the intraorganelle lumen but also, actively modifying cytosolic conditions.

scholarly journals Role of Arabidopsis Splicing factor SF1 in Temperature-Responsive Alternative Splicing of FLM pre-mRNA

2020 ◽  
Vol 11 ◽  
Author(s):  
Keh Chien Lee ◽  
Kyung Sook Chung ◽  
Hee Tae Lee ◽  
Jae-Hyeok Park ◽  
Jeong Hwan Lee ◽  
...  
Keyword(s):  
Alternative Splicing ◽  
Flowering Time ◽  
Crop Yields ◽  
Transcript Level ◽  
Splicing Factor ◽  
Loss Of Function ◽  
Temperature Dependent ◽  
Temperature Responsive ◽  
Different Temperatures

Small changes in temperature affect plant ecological and physiological factors that impact agricultural production. Hence, understanding how temperature affects flowering is crucial for decreasing the effects of climate change on crop yields. Recent reports have shown that FLM-β, the major spliced isoform of FLOWERING LOCUS M (FLM)—a flowering time gene, contributes to temperature-responsive flowering in Arabidopsis thaliana. However, the molecular mechanism linking pre-mRNA processing and temperature-responsive flowering is not well understood. Genetic and molecular analyses identified the role of an Arabidopsis splicing factor SF1 homolog, AtSF1, in regulating temperature-responsive flowering. The loss-of-function AtSF1 mutant shows temperature insensitivity at different temperatures and very low levels of FLM-β transcript, but a significantly increased transcript level of the alternative splicing (AS) isoform, FLM-δ. An RNA immunoprecipitation (RIP) assay revealed that AtSF1 is responsible for ambient temperature-dependent AS of FLM pre-mRNA, resulting in the temperature-dependent production of functional FLM-β transcripts. Moreover, alterations in other splicing factors such as ABA HYPERSENSITIVE1/CBP80 (ABH1/CBP80) and STABILIZED1 (STA1) did not impact the FLM-β/FLM-δ ratio at different temperatures. Taken together, our data suggest that a temperature-dependent interaction between AtSF1 and FLM pre-mRNA controls flowering time in response to temperature fluctuations.

scholarly journals MicroRNAs as Emerging Regulators of Signaling in the Tumor Microenvironment

Cancers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 911 ◽  
Author(s):  
Shahzad Nawaz Syed ◽  
Bernhard Brüne
Keyword(s):  
Tumor Microenvironment ◽  
Signaling Pathways ◽  
Target Identification ◽  
Cancer Therapeutics ◽  
Protein Translation ◽  
Transcriptional Gene Silencing ◽  
Post Transcriptional Gene Silencing ◽  
Cancer Initiation ◽  
Regulate Protein

A myriad of signaling molecules in a heuristic network of the tumor microenvironment (TME) pose a challenge and an opportunity for novel therapeutic target identification in human cancers. MicroRNAs (miRs), due to their ability to affect signaling pathways at various levels, take a prominent space in the quest of novel cancer therapeutics. The role of miRs in cancer initiation, progression, as well as in chemoresistance, is being increasingly investigated. The canonical function of miRs is to target mRNAs for post-transcriptional gene silencing, which has a great implication in first-order regulation of signaling pathways. However, several reports suggest that miRs also perform non-canonical functions, partly due to their characteristic non-coding small RNA nature. Examples emerge when they act as ligands for toll-like receptors or perform second-order functions, e.g., to regulate protein translation and interactions. This review is a compendium of recent advancements in understanding the role of miRs in cancer signaling and focuses on the role of miRs as novel regulators of the signaling pathway in the TME.

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