scholarly journals Host-induced silencing of the Colletotrichum gloeosporioides conidial morphology 1 gene (CgCOM1) confers resistance against Anthracnose disease in chilli and tomato

2020 ◽  
Author(s):  
Binod Kumar Mahto ◽  
Anjulata Singh ◽  
Manish Pareek ◽  
Manchikatla V. Rajam ◽  
Swatismita Dhar-Ray ◽  
...  

AbstractAnthracnose disease is caused by the ascomycetes fungal species Colletotrichum, which is responsible for heavy yield losses in chilli and tomato worldwide. Conventionally, harmful pesticides are used to contain anthracnose disease with limited success. In this study, we assessed the potential of Host-Induced Gene Silencing (HIGS) approach to target the Colletotrichum gloeosporioides COM1 (CgCOM1) developmental gene involved in the fungal conidial and appressorium formation, to restrict fungal infection in chilli and tomato fruits. For this study, we have developed stable transgenic lines of chilli and tomato expressing CgCOM1-RNAi construct employing Agrobacterium-mediated transformation. Transgenic plants were characterized by molecular and gene expression analyses. Production of specific CgCOM1 siRNA in transgenic chilli and tomato RNAi lines was confirmed by stem-loop RT-PCR. Fungal challenge assays on leaves and fruits showed that the transgenic lines were resistant to anthracnose disease-causing C. gloeosporioides in comparison to wild type and empty-vector control plants. RT-qPCR analyses in transgenic lines revealed barely any CgCOM1 transcripts in the C. gloeosporioides infected tissues, indicating near complete silencing of CgCOM1 gene expression in the pathogen. Microscopic examination of the Cg-challenged leaves of chilli-CgCOM1i lines revealed highly suppressed conidial germination, germ tube development, appressoria formation and mycelial growth of C. gloeosporioides, resulting in reduced infection of plant tissues. These results demonstrated highly efficient use of HIGS in silencing the expression of essential fungal developmental genes to inhibit the growth of pathogenic fungi, thus providing a highly precise approach to arrest the spread of disease.

2006 ◽  
Vol 33 (3) ◽  
pp. 289 ◽  
Author(s):  
Ling-Ling Gao ◽  
F. Andrew Smith ◽  
Sally E. Smith

A tomato mutant with reduced mycorrhizal colonisation, rmc, confers resistance to almost all arbuscular mycorrhizal (AM) fungal species tested, although there is variation in colonisation of different root cell layers by different fungi and one species of AM fungus can colonise this mutant relatively normally. These variations indicate a high degree of specificity in relation to AM colonisation. We explored the possibility of specificity or otherwise in interactions between rmc and three non-AM root-infecting fungi, Rhizoctonia solani anastomosis groups (AG) 4 and AG8, and binucleate Rhizoctonia (BNR). There were no differences between the wild type tomato 76R and rmc in the speed or extent to which these fungi infected roots or caused disease. Infection by R. solani induced high levels of defence-related gene expression in both tomato genotypes relative to non-infected plants. In contrast, with BNR the expression of these genes was not induced or induced to a much lower extent than with R. solani. The expression of defence-related genes with these two non-AM fungi was very similar in the two plant genotypes. It was different from effects observed during colonisation by AM fungi, which enhanced expression of defence-related genes in rmc compared with the wild type tomato. The specificity and molecular mechanisms of rmc in control of AM colonisation are discussed.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 1209-1209
Author(s):  
Susanna Harju ◽  
Halyna Fedosyuk ◽  
Kenneth R. Peterson

Abstract A 213 Kb human β-globin locus yeast artificial chromosome (β-YAC) was modified by homologous recombination to delete 2.9 Kb of cross-species conserved sequence similarity encompassing the LCR 5′HS4 (Δ5′HS4 β-YAC). Three transgenic mouse lines were established; each contained two intact copies of the β-globin locus as determined by long range restriction enzyme mapping (LRRM) and Southern blot hybridization analyses. Human ε-, γ- and β-globin, and mouse α- and ζ-globin mRNAs were measured by RNAse protection in hematopoietic tissues derived from staged embryos, fetuses and adult mice. No difference in the temporal pattern of globin transgene expression was observed between Δ5′HS4 β-YAC mice and wild-type β-YAC mice. In addition, quantitative per-copy human β-like globin mRNA levels were similar between Δ5′HS4 and wild-type β-YAC transgenic lines, although γ-globin gene expression was slightly increased in the fetal liver, while β-globin gene expression was slightly decreased in Δ5′HS4 β-YAC mice. These data are in contrast to data obtained from β-YAC mice containing a deletion of the 280 bp 5′HS4 core. In these mice, γ- and β-globin gene expression was significantly decreased during fetal definitive erythropoiesis and β-globin gene expression was decreased during adult definitive erythropoiesis. However, these data are consistent with the observation that deletion of the 5′HS core elements is more deleterious than large deletions of the 5′HSs. Together, the compiled deletion data supports the hypothesis that the LCR exists as a holocomplex in which the 5′HS cores form an active site and the flanking 5′HS regions constrain the holocomplex conformation. In this model, 5′HS core mutations are dominant negative, whereas larger deletions allow the LCR to fold into alternate holocomplex structures that function normally, albeit less efficiently. To complete the study on the contribution of the individual 5′HSs to LCR function, a 0.8 Kb 5′HS1 fragment was deleted in the 213 Kb β-YAC by homologous recombination. Two ΔHS1 β-YAC transgenic lines have been established; four additional founders were recently identified. Of the two lines, one contains two intact copies of the globin locus; the other contains four deleted copies, one of which extends from the LCR through just 5′ to the β-globin gene. For both lines, ε-globin gene expression was markedly reduced, approximately 5–10 fold, during primitive erythropoiesis. Developmental expression profiles and levels of the γ- and β-globin genes (in the line that contains loci including the β-globin gene) were unaffected by deletion of 5′HS1. Breeding of the remaining four founders to obtain F1 and F2 progeny for similar structure/function studies is in progress. Decreased expression of the β-globin gene is the first phenotype ascribed to a 5′HS1 mutation, suggesting that this HS does indeed have a role in LCR function.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 560-560 ◽  
Author(s):  
Ma. Reina Improgo ◽  
Adam Kiezun ◽  
Yaoyu Wang ◽  
Lillian Werner ◽  
Petar Stojanov ◽  
...  

Abstract Abstract 560 Nuclear factor kappa B (NF-κB) encompasses a family of transcription factors involved in oncogenic processes including cellular proliferation and apoptotic inhibition. Constitutive activation of NF-κB has been observed in hematologic malignancies and is thought to confer resistance to chemotherapeutic agents. Here, we examine the role of the NF-κB pathway in chronic lymphocytic leukemia (CLL). Whole-exome sequencing was performed using tumor and matched germline DNA from 167 CLL patients. We identified 51 patients (30%) carrying 53 non-silent somatic variants in genes of the canonical NF-κB pathway, which consists of 272 genes as defined by the Ingenuity Pathway Analysis tool. Of the 99 patients whose germline sequences have been analyzed to date, 27 patients (27%) carry 34 non-silent germline variants in NF-κB pathway genes. A total of 67 patients (40%) have at least one non-silent somatic or germline variant. Variants in the NFKB1 gene, itself, were also observed: a somatic variant, H66R, found in two patients, and two germline variants, Y89F and R849W, each found in one patient. To evaluate the functional consequences of the NFKB1 variants, we performed site-directed mutagenesis to generate full-length NFKB1 cDNAs encoding these variants. We subsequently measured transcriptional activity of wild-type and mutant NFKB1 via luciferase assays in HEK293T cells using reporter cassettes containing the NFKB1 response element. Transcriptional activity of the three NFKB1 variants was found to be at least 2-fold higher than that of wild-type NFKB1 (p<0.0001). We further hypothesized that this increased transcriptional activity would lead to increased expression of NFKB1 downstream target genes. Analysis of gene expression profiles from Affymetrix HG-U133 Plus 2.0 Arrays of 65 CLL patient samples showed that the NFKB1 downstream targets CCL3, CCL4, and CD69 are upregulated in NFKB1 variants. To validate these results, we performed quantitative RT-PCR in patients with (n=3) or without (n=9) NFKB1 variants and confirmed upregulation of CCL3 (p=0.0286), CCL4 (p=0.0384), and CD69 (p=0.0263). Direct transfection of HEK293T cells with NFKB1 variants also resulted in a 3.3-fold upregulation of CCL3 (p=0.05). To test the hypothesis that deregulation of the NF-κB pathway is a key mechanism in CLL, we compared gene expression profiles of NF-κB pathway genes between CLL patient samples (n=146) and normal B cells (n=16) and found overall upregulation of the NF-κB pathway in CLL (Kolmogorov-Smirnov test, p=2.2e-16). K-means clustering and principal component analysis (PCA) further revealed that CLL patients can be divided into two subgroups exhibiting differential magnitude of NF-κB pathway upregulation. Studies in progress aim to identify the clinical significance of these subgroups. Finally, we assessed the effect of inhibiting the NF-κB pathway using the cell permeant NF-κB inhibitor, SN50. We performed Annexin V/PI staining 24 hours post-treatment in CLL cells with (n=9) or without (n=3) NF-κB pathway variants. SN50 increased cell death 1.8-fold in all cells tested (p<0.0001). Quantitative RT-PCR also showed a 59% decrease in expression of CCL3 one hour post-treatment, confirming inhibition of the NF-κB pathway. In conclusion, our findings demonstrate that a high proportion of CLL patients harbor somatic and germline variants in NF-κB pathway genes, some of which appear to be functional. Furthermore, the NF-κB pathway is upregulated in CLL and pharmacological inhibition of the pathway leads to increased cancer cell death. Functional characterization of NF-κB pathway variants offers mechanistic insight into the disease, providing novel targets for therapy. Disclosures: No relevant conflicts of interest to declare.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Donghong Chen ◽  
Guofeng Zheng ◽  
Qing Yang ◽  
Le Luo ◽  
Jinglian Shen

Abstract Background IL-35 subunit EBI3 is up-regulated in pulmonary fibrosis tissues. In this study, we investigated the pathological role of EBI3 in pulmonary fibrosis and dissected the underlying molecular mechanism. Methods Bleomycin-induced pulmonary fibrosis mouse model was established, and samples were performed gene expression analyses through RNAseq, qRT-PCR and Western blot. Wild type and EBI3 knockout mice were exposed to bleomycin to investigate the pathological role of IL-35, via lung function and gene expression analyses. Primary lung epithelial cells were used to dissect the regulatory mechanism of EBI3 on STAT1/STAT4 and STAT3. Results IL-35 was elevated in both human and mouse with pulmonary fibrosis. EBI3 knockdown aggravated the symptoms of pulmonary fibrosis in mice. EBI3 deficiency enhanced the expressions of fibrotic and extracellular matrix-associated genes. Mechanistically, IL-35 activated STAT1 and STAT4, which in turn suppressed DNA enrichment of STAT3 and inhibited the fibrosis process. Conclusion IL-35 might be one of the potential therapeutic targets for bleomycin-induced pulmonary fibrosis.


Reproduction ◽  
2012 ◽  
Vol 143 (3) ◽  
pp. 359-375 ◽  
Author(s):  
Brent M Bany ◽  
Charles A Scott ◽  
Kirsten S Eckstrum

During decidualization, uterine natural killer (uNK) cells are the most abundant immune cell types found in the uterus. Although it is well known that they play key roles in spiral arteriole modification and the maintenance of decidual integrity seen after mid-pregnancy, their roles in the differentiation of decidual cells and accompanying angiogenesis during the process of decidualization is less well characterized. To address this, we used whole-genome Illumina BeadChip analysis to compare the gene expression profiles in implantation segments of the uterus during decidualization on day 7.5 of pregnancy between wild-type and uNK cell-deficient (interleukin-15-knockout) mice. We found almost 300 differentially expressed genes and verified the differential expression of ∼60 using quantitative RT-PCR. Notably, there was a lack of differential expression of genes involved in decidualization and angiogenesis and this was also verified by quantitative RT-PCR. Similar endothelial cell densities and proliferation indices were also found in the endometrium between the implantation site tissues of wild-type and knockout mice undergoing decidualization. Overall, the results of this study reveal that uNK cells likely do not play a major role in decidualization and accompanying angiogenesis during implantation. In addition, the study identifies a large number of genes whose expression in implantation-site uterine tissue during decidualization depends on interleukin-15 expression in mice.


2018 ◽  
Vol 10 (7) ◽  
pp. 122
Author(s):  
Debora Almeida Alcântara da Silva ◽  
Juliane Laner de Toledo ◽  
Flaviani Gabriela Pierdoná ◽  
Gabriel Sergio Costa Alves ◽  
Michelle de Souza Fayad André ◽  
...  

Allelopathy involves the release of compounds into the environment that affects the growth and development of other organisms. This phenomenon may lead to the production of compounds less harmful to the environment than traditional herbicides used in weed control. In plants, terpenes have been identified as components of allelochemicals and are synthesized by enzymes named as geranylgeranyl diphosphate synthases (GGPPS). There are about 12 GGPPS genes in Arabidopsis, among which is GGR. This work aims to study the association between the expression levels of GGR and the allelopathic response of sesame seedlings to Arabidopsis leaf extracts. Hence, the GGR gene was inserted into Arabidopsis with the purpose to investigate the allelopathic effects of GGR expression levels on sesame seedlings. GGR expression levels were quantified by RT-PCR in both transgenic and non-transgenic [wild-type (WT)] lines. It has been observed that both wild-type and GGR expressing transgenic lines inhibited the growth of sesame seedlings. However, it is noteworthy that the phytotoxicity of extracts from GGR lines were greater than WT extracts. RT-PCR analysis of GGR expression revealed that WT plants had higher levels of GGR expression than GGR transgenic lines, which suggests that a homologous-dependent gene silencing (HDGS) occurred in GGR lines. GGR is part of an enzyme complex that works as a hub that determines the types of terpenes produced in Arabidopsis chloroplasts. The present data indicates that decreases in GGR expression may have favoured the production of terpenes with stronger allelopathic capacity in Arabidopsis leaves.


2021 ◽  
Author(s):  
Rohan S. Wakade ◽  
Damian J. Krysan

AbstractSince its description in S. cerevisiae, the Regulation of Ace2 and Morphogenesis (RAM) pathway has been studied for nearly 20 years in multiple model and pathogenic fungi. In pathogenic fungi, the RAM pathway carries out many functions through mechanisms that remain to be defined in detail. Recently, we reported that Cbk1-mediated phosphorylation of the transcription factor Ace2 functions to repress the hyphae-to-yeast transition in Candida albicans. This transition is understudied relative to the yeast-to-hyphae transition. Subapical hyphal cell compartments are arrested in G1 until the point at which lateral yeast emerge. Here, we discuss this model and report new data indicating that a second G1 associated protein, the mitotic exit regulator Amn1. In S. cerevisiae diploid cells, Amn1 negatively regulates Ace2 at both the gene expression level through a negative feedback loop and at the protein level by targeting Ace2 for degradation. In C. albicans, Amn1 and Ace2 also form a feedback loop at the level of gene expression. Deletion of AMN1 decreases lateral yeast formation relative to wild type in maturing hyphae and is associated with decreased expression of PES1, a positive regulator of lateral yeast formation. These data indicate that the regulation of mitotic exit plays a role in determining the timing of lateral yeast emergence from hyphae in C. albicans. We also propose an integrated model for the interplay between the Cbk1-Ace2 axis and other hyphal stage regulators during the process of filamentation and transition back to yeast.


Cells ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 178 ◽  
Author(s):  
Ina Rudloff ◽  
Holly K. Ung ◽  
Jennifer K. Dowling ◽  
Ashley Mansell ◽  
Laura D’Andrea ◽  
...  

Interleukin (IL)-37 is a member of the IL-1 family of cytokines. Although its broad anti-inflammatory properties are well described, the effects of IL-37 on inflammasome function remain poorly understood. Performing gene expression analyses, ASC oligomerization/speck assays and caspase-1 assays in bone marrow-derived macrophages (BMDM), and employing an in vivo endotoxemia model, we studied how IL-37 affects the expression and maturation of IL-1β and IL-18, inflammasome activation, and pyroptosis in detail. IL-37 inhibited IL-1β production by NLRP3 and AIM2 inflammasomes, and IL-18 production by the NLRP3 inflammasome. This inhibition was partially attributable to effects on gene expression: whereas IL-37 did not affect lipopolysaccharide (LPS)-induced mRNA expression of Il18 or inflammasome components, IL-37-transgenic BMDM displayed an up to 83% inhibition of baseline and LPS-stimulated Il1b compared to their wild-type counterparts. Importantly, we observed that IL-37 suppresses nigericin- and silica-induced ASC oligomerization/speck formation (a step in inflammasome activation and subsequent caspase-1 activation), and pyroptosis (−50%). In mice subjected to endotoxemia, IL-37 inhibited plasma IL-1β (−78% compared to wild-type animals) and IL-18 (−61%). Thus, our study adds suppression of inflammasome activity to the portfolio of anti-inflammatory pathways employed by IL-37, highlighting this cytokine as a potential tool for treating inflammasome-driven diseases.


F1000Research ◽  
2019 ◽  
Vol 8 ◽  
pp. 273 ◽  
Author(s):  
Marian Seda ◽  
Emma Peskett ◽  
Charalambos Demetriou ◽  
Dale Bryant ◽  
Gudrun E. Moore ◽  
...  

Background: Lenz-Majewski syndrome (LMS) is characterized by osteosclerosis and hyperostosis of skull, vertebrae and tubular bones as well as craniofacial, dental, cutaneous, and digit abnormalities. We previously found that LMS is caused by de novo dominant missense mutations in the PTDSS1 gene, which encodes phosphatidylserine synthase 1 (PSS1), an enzyme that catalyses the conversion of phosphatidylcholine to phosphatidylserine. The mutations causing LMS result in a gain-of-function, leading to increased enzyme activity and blocking end-product inhibition of PSS1. Methods: Here, we have used transpose-mediated transgenesis to attempt to stably express wild-type and mutant forms of human PTDSS1 ubiquitously or specifically in chondrocytes, osteoblasts or osteoclasts in zebrafish. Results: We report multiple genomic integration sites for each of 8 different transgenes. While we confirmed that the ubiquitously driven transgene constructs were functional in terms of driving gene expression following transient transfection in HeLa cells, and that all lines exhibited expression of a heart-specific cistron within the transgene, we failed to detect PTDSS1 gene expression at either the RNA or protein levels in zebrafish. All wild-type and mutant transgenic lines of zebrafish exhibited mild scoliosis with variable incomplete penetrance which was never observed in non-transgenic animals. Conclusions: Collectively the data suggest that the transgenes are silenced, that animals with integrations that escape silencing are not viable, or that other technical factors prevent transgene expression. In conclusion, the incomplete penetrance of the phenotype and the lack of a matched transgenic control model precludes further meaningful investigations of these transgenic lines.


2006 ◽  
Vol 61 (9-10) ◽  
pp. 699-703 ◽  
Author(s):  
András Bittsánszky ◽  
Gábor Gyulai ◽  
Mervyn Humphreys ◽  
Gábor Gullner ◽  
Zsolt Csintalan ◽  
...  

Abstract Stress response capacity (Fv/Fm at 690 nm and F690/F735 at Fmax) of untransformed hybrid poplar, Populus × canescens (P. tremula × P. alba), and two transgenic lines overexpressing γ-ECS (γ-glutamylcysteine synthetase) either in the cytosol (cyt-ECS) or in the chloroplast (chl-ECS) was studied in response to the herbicide paraquat (4.0 × 10-9 to 4.0 × 10-6 m) for 21 days. Significant differences at sublethal (4.0 × 10-7 m) and bleaching (4.0 × 10-6 m) concentrations of paraquat were observed with about a two-fold and eight-fold decrease in the photosynthetic activity (Fv/Fm at 690 nm and F690/F735 at Fmax), respectively. None of the gshI transgenic lines (cyt-ECS, chl-ECS) with elevated GSH content exhibited significant tolerance to paraquat. Semiquantitative RT-PCR of the cyt-ECS clone was used for gene expression analysis of the nuclear encoded rbcS gene and the stress responsive gst gene. Expression of the constitutively expressed 26SrRNA ribosomal gene was probed as a control for all RT-PCR reactions. The relative intensities of gene expressions normalized to the level of 26SrRNA intensity showed a 50% decrease in the nuclear encoded rbcS expression and a 120% increase in the stress responsive gst gene expression of the paraquat treated (4.0 × 10-7 m) samples of the transgenic poplar line (cyt-ECS).


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