scholarly journals Jasmonate inhibits adventitious root initiation through transcriptional repression of CKX1 and activation of RAP2.6L transcription factor in Arabidopsis

2021 ◽  
Author(s):  
Asma Dob ◽  
Abdellah Lakehal ◽  
Ondrej Novak ◽  
Catherine Bellini
Keyword(s):  
Transcription Factor ◽  
Transcriptional Repression ◽  
Adventitious Root ◽  
De Novo ◽  
Constitutive Expression ◽  
Transcriptome Profiling ◽  
Adventitious Rooting ◽  
Cytokinin Oxidase ◽  
Root Initiation ◽  
Base Content

AbstractAdventitious rooting is a de novo organogenesis process that enables plants to propagate clonally and cope with environmental stresses. Adventitious root initiation (ARI) is controlled by interconnected transcriptional and hormonal networks, but there is little knowledge of the genetic and molecular programs orchestrating these networks. Thus, we have applied genome-wide transcriptome profiling to elucidate the profound transcriptional reprogramming events preceding ARI. These reprogramming events are associated with downregulation of cytokinin (CK) signaling and response genes, which could be triggers for ARI. Interestingly, we found that CK free-base content declined during ARI, due to downregulation of de novo CK biosynthesis and upregulation of CK inactivation pathways. We also found that MYC2-dependent jasmonate (JA) signaling inhibits ARI by downregulating expression of the CYTOKININ OXIDASE/DEHYDROGENASE1 gene. We also demonstrated that JA and CK synergistically activate expression of RELATED to APETALA2.6 LIKE (RAP2.6L) transcription factor, and constitutive expression of this transcription factor strongly inhibits ARI. Collectively, our findings reveal that previously unknown genetic interactions between JA and CK play key roles in ARI

scholarly journals Identification of Genes Underlying the Resistance to Melampsora larici-populina in an R Gene Supercluster of the Populus deltoides Genome

Plant Disease ◽  
2020 ◽  
Vol 104 (4) ◽  
pp. 1133-1143
Author(s):  
Suyun Wei ◽  
Huaitong Wu ◽  
Xiaoping Li ◽  
Yingnan Chen ◽  
Yonghua Yang ◽  
...  
Keyword(s):  
Populus Deltoides ◽  
De Novo ◽  
Quantitative Resistance ◽  
Rust Fungus ◽  
Constitutive Expression ◽  
Transcriptome Profiling ◽  
R Gene ◽  
R Genes ◽  
Sequencing Data ◽  
Key Genes

Identification of the particular genes in an R genes supercluster underlying resistance to the rust fungus Melampsora larici-populina in poplar genome remains challenging. Based on the de novo assembly of the Populus deltoides genome, all of the detected major genetic loci conferring resistance to M. larici-populina were confined to a 3.5-Mb region on chromosome 19. The transcriptomes of the resistant and susceptible genotypes were sequenced for a timespan from 0 to 168 hours postinoculation. By mapping the differentially expressed genes to the target genomic region, we identified two constitutive expression R genes and one inducible expression R gene that might confer resistance to M. larici-populina. Nucleotide variations were predicted based on the reconstructed haplotypes for each allele of the candidate genes. We also confirmed that salicylic acid was the phytohormone mediating signal transduction pathways, and PR-1 was identified as a key gene inhibiting rust reproduction. Finally, quantitative reverse transcription PCR assay revealed consistent expressions with the RNA-sequencing data for the detected key genes. This study presents an efficient approach for the identification of particular genes underlying phenotype of interest by the combination of genetic mapping, transcriptome profiling, and candidate gene sequences dissection. The identified key genes would be useful for host resistance diagnosis and for molecular breeding of elite poplar cultivars exhibiting resistance to M. larici-populina infection. The detected R genes are also valuable for testing whether the combination of individual R genes can induce durable quantitative resistance.

scholarly journals Fli-1, an Ets-Related Transcription Factor, Regulates Erythropoietin-Induced Erythroid Proliferation and Differentiation: Evidence for Direct Transcriptional Repression of the Rb Gene during Differentiation

1999 ◽  
Vol 19 (6) ◽  
pp. 4452-4464 ◽  
Author(s):  
Ami Tamir ◽  
Jeff Howard ◽  
Rachel R. Higgins ◽  
You-Jun Li ◽  
Lloyd Berger ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Transcriptional Repression ◽  
Target Genes ◽  
Leukemia Virus ◽  
Constitutive Expression ◽  
Erythroid Differentiation ◽  
Consensus Binding Site ◽  
Erythroid Progenitor ◽  
Proliferation And Differentiation ◽  
Related Transcription Factor

ABSTRACT Erythropoietin (Epo) is a major regulator of erythropoiesis that alters the survival, proliferation, and differentiation of erythroid progenitor cells. The mechanism by which these events are regulated has not yet been determined. Using HB60, a newly established erythroblastic cell line, we show here that Epo-induced terminal erythroid differentiation is associated with a transient downregulation in the expression of the Ets-related transcription factor Fli-1. Constitutive expression of Fli-1 in HB60 cells, similar to retroviral insertional activation of Fli-1 observed in Friend murine leukemia virus (F-MuLV)-induced erythroleukemia, blocks Epo-induced differentiation while promoting Epo-induced proliferation. These results suggest that Fli-1 modulates the response of erythroid cells to Epo. To understand the mechanism by which Fli-1 regulates erythropoiesis, we searched for downstream target genes whose expression is regulated by this transcription factor. Here we show that the retinoblastoma (Rb) gene, which was previously shown to be involved in the development of mature erythrocytes, contains a Fli-1 consensus binding site within its promoter. Fli-1 binds to this cryptic Ets consensus site within the Rb promoter and transcriptionally represses Rb expression. Both the expression level and the phosphorylation status of Rb are consistent with the response of HB60 cells to Epo-induced terminal differentiation. We suggest that the negative regulation ofRb by Fli-1 could be one of the critical determinants in erythroid progenitor cell differentiation that is specifically deregulated during F-MuLV-induced erythroleukemia.

scholarly journals Metabolic gene regulation by Drosophila GATA transcription factor Grain

PLoS Genetics ◽  
2021 ◽  
Vol 17 (10) ◽  
pp. e1009855
Author(s):  
Krista Kokki ◽  
Nicole Lamichane ◽  
Anni I. Nieminen ◽  
Hanna Ruhanen ◽  
Jack Morikka ◽  
...  
Keyword(s):  
Gene Expression ◽  
Gene Regulation ◽  
Transcription Factor ◽  
De Novo ◽  
Constitutive Expression ◽  
Physiological Adaptation ◽  
Dependent Manner ◽  
Metabolic Gene ◽  
High Sugar ◽  
Gata Transcription Factor

Nutrient-dependent gene regulation critically contributes to homeostatic control of animal physiology in changing nutrient landscape. In Drosophila, dietary sugars activate transcription factors (TFs), such as Mondo-Mlx, Sugarbabe and Cabut, which control metabolic gene expression to mediate physiological adaptation to high sugar diet. TFs that correspondingly control sugar responsive metabolic genes under conditions of low dietary sugar remain, however, poorly understood. Here we identify a role for Drosophila GATA TF Grain in metabolic gene regulation under both low and high sugar conditions. De novo motif prediction uncovered a significant over-representation of GATA-like motifs on the promoters of sugar-activated genes in Drosophila larvae, which are regulated by Grain, the fly ortholog of GATA1/2/3 subfamily. grain expression is activated by sugar in Mondo-Mlx-dependent manner and it contributes to sugar-responsive gene expression in the fat body. On the other hand, grain displays strong constitutive expression in the anterior midgut, where it drives lipogenic gene expression also under low sugar conditions. Consistently with these differential tissue-specific roles, Grain deficient larvae display delayed development on high sugar diet, while showing deregulated central carbon and lipid metabolism primarily on low sugar diet. Collectively, our study provides evidence for the role of a metazoan GATA transcription factor in nutrient-responsive metabolic gene regulation in vivo.

scholarly journals Transcriptome profiling of Lymnaea stagnalis (Gastropoda) for ecoimmunological research

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Otto Seppälä ◽  
Jean-Claude Walser ◽  
Teo Cereghetti ◽  
Katri Seppälä ◽  
Tiina Salo ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Individual Variation ◽  
Lymnaea Stagnalis ◽  
De Novo ◽  
Transcriptome Profiling ◽  
Snail Species ◽  
Immune Defence ◽  
Immune Activity ◽  
Self Recognition ◽  
Immune Assays

Abstract Background Host immune function can contribute to numerous ecological/evolutionary processes. Ecoimmunological studies, however, typically use one/few phenotypic immune assays and thus do not consider the complexity of the immune system. Therefore, “omics” resources that allow quantifying immune activity across multiple pathways are needed for ecoimmunological models. We applied short-read based RNAseq (Illumina NextSeq 500, PE-81) to characterise transcriptome profiles of Lymnaea stagnalis (Gastropoda), a multipurpose model snail species. We used a genetically diverse snail stock and exposed individuals to immune elicitors (injury, bacterial/trematode pathogens) and changes in environmental conditions that can alter immune activity (temperature, food availability). Results Immune defence factors identified in the de novo assembly covered elements broadly described in other gastropods. For instance, pathogen-recognition receptors (PRR) and lectins activate Toll-like receptor (TLR) pathway and cytokines that regulate cellular and humoral defences. Surprisingly, only modest diversity of antimicrobial peptides and fibrinogen related proteins were detected when compared with other taxa. Additionally, multiple defence factors that may contribute to the phenotypic immune assays used to quantify antibacterial activity and phenoloxidase (PO)/melanisation-type reaction in this species were found. Experimental treatments revealed factors from non-self recognition (lectins) and signalling (TLR pathway, cytokines) to effectors (e.g., antibacterial proteins, PO enzymes) whose transcription depended on immune stimuli and environmental conditions, as well as components of snail physiology/metabolism that may drive these effects. Interestingly, the transcription of many factors (e.g., PRR, lectins, cytokines, PO enzymes, antibacterial proteins) showed high among-individual variation. Conclusions Our results indicate several uniform aspects of gastropod immunity, but also apparent differences between L. stagnalis and some previously examined taxa. Interestingly, in addition to immune defence factors that responded to immune elicitors and changes in environmental conditions, many factors showed high among-individual variation across experimental snails. We propose that such factors are highly important to be included in future ecoimmunological studies because they may be the key determinants of differences in parasite resistance among individuals both within and between natural snail populations.

Early biochemical events during adventitious root initiation in the hypocotyl of Phaseolus vulgaris

1979 ◽  
Vol 18 (3) ◽  
pp. 383-387 ◽  
Author(s):  
G.R. Kantharaj ◽  
S. Mahadevan ◽  
G. Padmanaban
Keyword(s):  
Phaseolus Vulgaris ◽  
Adventitious Root ◽  
Root Initiation
Sign in / Sign up

Export Citation Format

Share Document