scholarly journals Aluminum Resistance Transcription Factor 1 (ART1) contributes to natural variation in rice Al resistance

2017 ◽  
Author(s):  
Juan David Arbelaez ◽  
Lyza G. Maron ◽  
Timothy O. Jobe ◽  
Miguel A. Piñeros ◽  
Adam N. Famoso ◽  
...  

ABSTRACTTranscription factors (TFs) mediate stress resistance indirectly via physiological mechanisms driven by the genes they regulate. When studying TF-mediated stress resistance, it is important to understand how TFs interact with different genetic backgrounds. Here, we fine-mapped the aluminum (Al) resistance QTL Alt12.1 to a 44 Kb region containing six gene models. Among them is ART1, which encodes a C2H2-type zinc finger TF required for Al resistance in rice. The parents of the mapping population, Al-resistant Azucena (tropical japonica) and Al-sensitive IR64 (indica), showed similar ART1 expression levels but extensive sequence polymorphism within the ART1 coding region. Using reciprocal near-isogenic lines (NILs) in the Azucena and IR64 genetic backgrounds, we examined how allele-swapping Alt12.1 would affect plant responses to Al. Analysis of global transcriptional responses to Al stress in roots of the NILs alongside their recurrent parents demonstrated that the ART1 from Al-resistant Azucena led to greater changes in gene expression in response to Al when compared to the ART1 from IR64 in both genetic backgrounds. The presence of the ART1 allele from the opposite parent affected the expression of several genes not previously implicated in rice Al tolerance. We highlight examples where putatively functional variation in cis-regulatory regions of ART1-regulated genes interacts with ART1 to determine gene expression in response to Al. This ART1-promoter interaction may be associated with transgressive variation for Al resistance in the Azucena × IR64 population. These results illustrate how ART1 interacts with the genetic background to contribute to quantitative phenotypic variation in rice Al resistance.

2021 ◽  
Author(s):  
Luis O Morales ◽  
Alexey Shapiguzov ◽  
Omid Safronov ◽  
Johanna Leppälä ◽  
Lauri Vaahtera ◽  
...  

Abstract Tropospheric ozone (O3) is a major air pollutant that decreases yield of important crops worldwide. Despite long-lasting research of its negative effects on plants, there are many gaps in our knowledge on how plants respond to O3. In this study, we used natural variation in the model plant Arabidopsis (Arabidopsis thaliana) to characterize molecular and physiological mechanisms underlying O3 sensitivity. A key parameter in models for O3 damage is stomatal uptake. Here we show that the extent of O3 damage in the sensitive Arabidopsis accession Shahdara (Sha) does not correspond with O3 uptake, pointing toward stomata-independent mechanisms for the development of O3 damage. We compared tolerant (Col-0) versus sensitive accessions (Sha, Cvi-0) in assays related to photosynthesis, cell death, antioxidants, and transcriptional regulation. Acute O3 exposure increased cell death, development of lesions in the leaves, and decreased photosynthesis in sensitive accessions. In both Sha and Cvi-0, O3-induced lesions were associated with decreased maximal chlorophyll fluorescence and low quantum yield of electron transfer from Photosystem II to plastoquinone. However, O3-induced repression of photosynthesis in these two O3-sensitive accessions developed in different ways. We demonstrate that O3 sensitivity in Arabidopsis is influenced by genetic diversity given that Sha and Cvi-0 developed accession-specific transcriptional responses to O3. Our findings advance the understanding of plant responses to O3 and set a framework for future studies to characterize molecular and physiological mechanisms allowing plants to respond to high O3 levels in the atmosphere as a result of high air pollution and climate change.


Life ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1010
Author(s):  
James Sheppard ◽  
Eric S. Land ◽  
Tiffany Aurora Toennisson ◽  
Colleen J. Doherty ◽  
Imara Y. Perera

Although many reports characterize the transcriptional response of Arabidopsis seedlings to microgravity, few investigate the effect of partial or fractional gravity on gene expression. Understanding plant responses to fractional gravity is relevant for plant growth on lunar and Martian surfaces. The plant signaling flight experiment utilized the European Modular Cultivation System (EMCS) onboard the International Space Station (ISS). The EMCS consisted of two rotors within a controlled chamber allowing for two experimental conditions, microgravity (stationary rotor) and simulated gravity in space. Seedlings were grown for 5 days under continuous light in seed cassettes. The arrangement of the seed cassettes within each experimental container results in a gradient of fractional g (in the spinning rotor). To investigate whether gene expression patterns are sensitive to fractional g, we carried out transcriptional profiling of root samples exposed to microgravity or partial g (ranging from 0.53 to 0.88 g). Data were analyzed using DESeq2 with fractional g as a continuous variable in the design model in order to query gene expression across the gravity continuum. We identified a subset of genes whose expression correlates with changes in fractional g. Interestingly, the most responsive genes include those encoding transcription factors, defense, and cell wall-related proteins and heat shock proteins.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alejandro Garcia ◽  
M. Estrella Santamaria ◽  
Isabel Diaz ◽  
Manuel Martinez

AbstractThe success in the response of a plant to a pest depends on the regulatory networks that connect plant perception and plant response. Meta-analyses of transcriptomic responses are valuable tools to discover novel mechanisms in the plant/herbivore interplay. Considering the quantity and quality of available transcriptomic analyses, Arabidopsis thaliana was selected to test the ability of comprehensive meta-analyses to disentangle plant responses. The analysis of the transcriptomic data showed a general induction of biological processes commonly associated with the response to herbivory, like jasmonate signaling or glucosinolate biosynthesis. However, an uneven induction of many genes belonging to these biological categories was found, which was likely associated with the particularities of each specific Arabidopsis-herbivore interaction. A thorough analysis of the responses to the lepidopteran Pieris rapae and the spider mite Tetranychus urticae highlighted specificities in the perception and signaling pathways associated with the expression of receptors and transcription factors. This information was translated to a variable alteration of secondary metabolic pathways. In conclusion, transcriptomic meta-analysis has been revealed as a potent way to sort out relevant physiological processes in the plant response to herbivores. Translation of these transcriptomic-based analyses to crop species will permit a more appropriate design of biotechnological programs.


Genetics ◽  
2002 ◽  
Vol 160 (2) ◽  
pp. 595-608 ◽  
Author(s):  
Jody Hey ◽  
Richard M Kliman

AbstractIn Drosophila, as in many organisms, natural selection leads to high levels of codon bias in genes that are highly expressed. Thus codon bias is an indicator of the intensity of one kind of selection that is experienced by genes and can be used to assess the impact of other genomic factors on natural selection. Among 13,000 genes in the Drosophila genome, codon bias has a slight positive, and strongly significant, association with recombination—as expected if recombination allows natural selection to act more efficiently when multiple linked sites segregate functional variation. The same reasoning leads to the expectation that the efficiency of selection, and thus average codon bias, should decline with gene density. However, this prediction is not confirmed. Levels of codon bias and gene expression are highest for those genes in an intermediate range of gene density, a pattern that may be the result of a tradeoff between the advantages for gene expression of close gene spacing and disadvantages arising from regulatory conflicts among tightly packed genes. These factors appear to overlay the more subtle effect of linkage among selected sites that gives rise to the association between recombination rate and codon bias.


2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Tal Gutman ◽  
Guy Goren ◽  
Omri Efroni ◽  
Tamir Tuller

AbstractIn recent years it has been shown that silent mutations, in and out of the coding region, can affect gene expression and may be related to tumorigenesis and cancer cell fitness. However, the predictive ability of these mutations for cancer type diagnosis and prognosis has not been evaluated yet. In the current study, based on the analysis of 9,915 cancer genomes and approximately three million mutations, we provide a comprehensive quantitative evaluation of the predictive power of various types of silent and non-silent mutations over cancer classification and prognosis. The results indicate that silent-mutation models outperform the equivalent null models in classifying all examined cancer types and in estimating the probability of survival 10 years after the initial diagnosis. Additionally, combining both non-silent and silent mutations achieved the best classification results for 68% of the cancer types and the best survival estimation results for up to nine years after the diagnosis. Thus, silent mutations hold considerable predictive power over both cancer classification and prognosis, most likely due to their effect on gene expression. It is highly advised that silent mutations are integrated in cancer research in order to unravel the full genomic landscape of cancer and its ramifications on cancer fitness.


1991 ◽  
Vol 11 (1) ◽  
pp. 55-62 ◽  
Author(s):  
M A Marshall ◽  
W E Timberlake

The Aspergillus nidulans wetA gene is required for synthesis of cell wall layers that make asexual spores (conidia) impermeable. In wetA mutant strains, conidia take up water and autolyze rather than undergoing the final stages of maturation. wetA is activated during conidiogenesis by sequential expression of the brlA and abaA regulatory genes. To determine whether wetA regulates expression of other sporulation-specific genes, its coding region was fused to a nutritionally regulated promoter that permits gene activation in vegetative cells (hyphae) under conditions that suppress conidiation. Expression of wetA in hyphae inhibited growth and caused excessive branching. It did not lead to activation of brlA or abaA but did cause accumulation of transcripts from genes that are normally expressed specifically during the late stages of conidiation and whose mRNAs are stored in mature spores. Thus, wetA directly or indirectly regulates expression of some spore-specific genes. At least one gene (wA), whose mRNA does not occur in spores but rather accumulates in the sporogenous phialide cells, was activated by wetA, suggesting that wetA may have a regulatory function in these cells as well as in spores. We propose that wetA is responsible for activating a set of genes whose products make up the final two conidial wall layers or direct their assembly and through this activity is responsible for acquisition of spore dormancy.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Anastasia Ricci ◽  
Sara Orazi ◽  
Federica Biancucci ◽  
Mauro Magnani ◽  
Michele Menotta

AbstractAtaxia telangiectasia (AT) is a rare genetic neurodegenerative disease. To date, there is no available cure for the illness, but the use of glucocorticoids has been shown to alleviate the neurological symptoms associated with AT. While studying the effects of dexamethasone (dex) in AT fibroblasts, by chance we observed that the nucleoplasmic Lamin A/C was affected by the drug. In addition to the structural roles of A-type lamins, Lamin A/C has been shown to play a role in the regulation of gene expression and cell cycle progression, and alterations in the LMNA gene is cause of human diseases called laminopathies. Dex was found to improve the nucleoplasmic accumulation of soluble Lamin A/C and was capable of managing the large chromatin Lamin A/C scaffolds contained complex, thus regulating epigenetics in treated cells. In addition, dex modified the interactions of Lamin A/C with its direct partners lamin associated polypeptide (LAP) 2a, Retinoblastoma 1 (pRB) and E2F Transcription Factor 1 (E2F1), regulating local gene expression dependent on E2F1. These effects were differentially observed in both AT and wild type (WT) cells. To our knowledge, this is the first reported evidence of the role of dex in Lamin A/C dynamics in AT cells, and may represent a new area of research regarding the effects of glucocorticoids on AT. Moreover, future investigations could also be extended to healthy subjects or to other pathologies such as laminopathies since glucocorticoids may have other important effects in these contexts as well.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mark G. Sterken ◽  
Marijke H. van Wijk ◽  
Elizabeth C. Quamme ◽  
Joost A. G. Riksen ◽  
Lucinda Carnell ◽  
...  

AbstractEthanol-induced transcriptional changes underlie important physiological responses to ethanol that are likely to contribute to the addictive properties of the drug. We examined the transcriptional responses of Caenorhabditis elegans across a timecourse of ethanol exposure, between 30 min and 8 h, to determine what genes and genetic pathways are regulated in response to ethanol in this model. We found that short exposures to ethanol (up to 2 h) induced expression of metabolic enzymes involved in metabolizing ethanol and retinol, while longer exposure (8 h) had much more profound effects on the transcriptome. Several genes that are known to be involved in the physiological response to ethanol, including direct ethanol targets, were regulated at 8 h of exposure. This longer exposure to ethanol also resulted in the regulation of genes involved in cilia function, which is consistent with an important role for the effects of ethanol on cilia in the deleterious effects of chronic ethanol consumption in humans. Finally, we found that food deprivation for an 8-h period induced gene expression changes that were somewhat ameliorated by the presence of ethanol, supporting previous observations that worms can use ethanol as a calorie source.


1988 ◽  
Vol 8 (8) ◽  
pp. 3439-3447 ◽  
Author(s):  
W Bajwa ◽  
T E Torchia ◽  
J E Hopper

GAL3 gene expression is required for rapid GAL4-mediated galactose induction of the galactose-melibiose regulon genes in Saccharomyces cerevisiae. Here we show by Northern (RNA) blot analysis that GAL3 gene expression is itself galactose inducible. Like the GAL1, GAL7, GAL10, and MEL1 genes, the GAL3 gene is severely glucose repressed. Like the MEL1 gene, but in contrast to the GAL1, GAL7, and GAL10 genes, GAL3 is expressed at readily detectable basal levels in cells grown in noninducing, nonrepressing media. We determined the sequence of the S. cerevisiae GAL3 gene and its 5'-noncoding region. Within the 5'-noncoding region of the GAL3 gene, we found two sequences similar to the UASGal elements of the other galactose-melibiose regulon genes. Deletion analysis indicated that only the most ATG proximal of these sequences is required for GAL3 expression. The coding region of GAL3 consists of a 1,275-base-pair open reading frame in the direction of transcription. A comparison of the deduced 425-amino-acid sequence with the protein data bank revealed three regions of striking similarity between the GAL3 protein and the GAL1-specified galactokinase of Saccharomyces carlsbergensis. One of these regions also showed striking similarity to sequences within the galactokinase protein of Escherichia coli. On the basis of these protein sequence similarities, we propose that the GAL3 protein binds a molecule identical to or structurally related to one of the substrates or products of the galactokinase-catalyzed reaction.


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