scholarly journals The Secreted Protein MoHrip1 Is Necessary for the Virulence of Magnaporthe oryzae

2019 ◽  
Vol 20 (7) ◽  
pp. 1643 ◽  
Author(s):  
Hai-Zhen Nie ◽  
Lin Zhang ◽  
Hui-Qian Zhuang ◽  
Wen-Jiong Shi ◽  
Xiu-Fen Yang ◽  
...  
Keyword(s):  
Fungal Infection ◽  
Magnaporthe Oryzae ◽  
Biological Function ◽  
Secreted Protein ◽  
Rice Seedlings ◽  
Fungal Virulence ◽  
Complementation Strain ◽  
Rice Leaves ◽  
Inoculation Assay

Secreted effectors from Magnaporthe oryzae play critical roles in the interaction with rice to facilitate fungal infection and disease development. M. oryzae-secreted protein MoHrip1 can improve plant defense as an elicitor in vitro, however, its biological function in fungal infection is not clear. In this study, we found that the expression of mohrip1 was significantly induced in the stages of fungal penetration and colonization. Although dispensable for the growth and conidiation, MoHrip1 was necessary for the full virulence of M. oryzae. Deletion of mohrip1 remarkably compromised fungal virulence on rice seedlings and even on rice leaves with wounds. Rice sheath inoculation assay further demonstrated the defects of mohrip1-deleted mutants on penetration and proliferation in rice cells. Additionally, compared with WT and complementation strain, the inoculation of mohrip1-deleted mutants induced a higher expression of specific defense related genes and a higher production of specific defensive compounds in rice leaves. These data collectively indicated that MoHrip1 is necessary for fungal penetration and invasive expansion, and further full virulence of rice blast fungus.

scholarly journals Essential Roles of Two FRQ Proteins (Frq1/2) in Virulence, Infection Cycle and Calcofluor-Specific Signaling of Beauveria bassiana

2021 ◽  
Author(s):  
Sen-Miao Tong ◽  
Ben-Jie Gao ◽  
Han Peng ◽  
Ming-Guang Feng
Keyword(s):  
Signal Transduction ◽  
Cell Wall ◽  
Fungal Infection ◽  
Beauveria Bassiana ◽  
High Resistance ◽  
Infection Cycle ◽  
Fungal Virulence ◽  
Specific Signal ◽  
Insight Into

Two FRQ proteins (Frq1/2) distinct in molecular mass and structure coexist in Beauveria bassiana, an asexual insect-pathogenic fungus. Frq1 and Frq2 have been proven to have opposite nuclear rhythms that can persistently activate developmental activator genes, and hence orchestrate nonrhythmic conidiation in vitro under light or in darkness. Here, we report an essentiality of either FRQ, but greater importance of Frq2 than of Frq1, for the fungal virulence and infection cycle. The fungal virulence was attenuated significantly more in the absence of frq2 than of frq1 through either normal cuticle infection or cuticle-bypassing infection by intrahemocoel injection, accompanied by differentially reduced secretion of Pr1 proteases required for the cuticle infection and delayed development of hyphal bodies in vivo, which usually propagate by yeast-like budding in host hemocoel to accelerate insect death from mycosis. Despite insignificant changes in radial growth under normal, oxidative and hyperosmotic culture conditions, conidial yields of the Δfrq1 and Δfrq2 mutants on insect cadavers were sharply reduced, and the reduction increased with shortening daylight length on day 9 or 12 after death, indicating that both Frq1 and Frq2 are required for the fungal infection cycle in host habitats. Intriguingly, the Δfrq1 and Δfrq2 mutants showed hypersensitivity and high resistance to cell-wall perturbing calcafluor white, coinciding well with MAPK/Slt2 required for mediation of cell wall integrity being hypo- and hyper-phosphorylated in their calcofluor-triggered cells, respectively. This finding offers a novel insight into opposite roles of Frq1 and Frq2 in calcafluor-specific signal transduction via the fungal Slt2 cascade. IMPORTANCE Opposite nuclear rhythms of two distinct FRQ proteins (Frq1/2) coexisting in an asexual fungal insect pathogen have been shown to orchestrate the fungal nonrhythmic conidiation in vitro in a circadian day independent of photoperiod change. This paper reports essential roles of both Frq1 and Frq2, but greater role of Frq2, in sustaining the fungal virulence and infection cycle since either frq1 or frq2 deletion led to marked delay of lethal action against a model insect and drastic reduction of conidial yield on insect cadavers. Moreover, the frq1 and frq2 mutants display hypersensitivity and high resistance to cell wall perturbation and have hypo- and hyper-phosphorylated MAPK/Slt2 in calcafluor white-triggered cells, respectively. These findings uncover a requirement of Frq1 and Frq2 for the fungal infection cycle in host habitats and provide a novel insight into their opposite roles in calcafluor-specific signal transduction through the MAPK/Slt2 cascade.

scholarly journals Thromboxane Mobilizes Insect Blood Cells to Infection Foci

2021 ◽  
Vol 12 ◽  
Author(s):  
Miltan Chandra Roy ◽  
Kiwoong Nam ◽  
Jaesu Kim ◽  
David Stanley ◽  
Yonggyun Kim
Keyword(s):  
Immune Responses ◽  
Fungal Infection ◽  
Blood Cells ◽  
Specific Inhibitor ◽  
Cell Aggregation ◽  
Fungal Virulence ◽  
Metarhizium Rileyi ◽  
Cox Inhibitor ◽  
Thromboxane Receptors

Innate immune responses are effective for insect survival to defend against entomopathogens including a fungal pathogen, Metarhizium rileyi, that infects a lepidopteran Spodoptera exigua. In particular, the fungal virulence was attenuated by cellular immune responses, in which the conidia were phagocytosed by hemocytes (insect blood cells) and hyphal growth was inhibited by hemocyte encapsulation. However, the chemokine signal to drive hemocytes to the infection foci was little understood. The hemocyte behaviors appeared to be guided by a Ca2+ signal stimulating cell aggregation to the infection foci. The induction of the Ca2+ signal was significantly inhibited by the cyclooxygenase (COX) inhibitor. Under the inhibitory condition, the addition of thromboxane A2 or B2 (TXA2 or TXB2) among COX products was the most effective to recover the Ca2+ signal and hemocyte aggregation. TXB2 alone induced a microaggregation behavior of hemocytes under in vitro conditions. Indeed, TXB2 titer was significantly increased in the plasma of the infected larvae. The elevated TXB2 level was further supported by the induction of phospholipase A2 (PLA2) activity in the hemocytes and subsequent up-regulation of COX-like peroxinectins (SePOX-F and SePOX-H) in response to the fungal infection. Finally, the expression of a thromboxane synthase (Se-TXAS) gene was highly expressed in the hemocytes. RNA interference (RNAi) of Se-TXAS expression inhibited the Ca2+ signal and hemocyte aggregation around fungal hyphae, which were rescued by the addition of TXB2. Without any ortholog to mammalian thromboxane receptors, a prostaglandin receptor was essential to mediate TXB2 signal to elevate the Ca2+ signal and mediate hemocyte aggregation behavior. Specific inhibitor assays suggest that the downstream signal after binding TXB2 to the receptor follows the Ca2+-induced Ca2+ release pathway from the endoplasmic reticulum of the hemocytes. These results suggest that hemocyte aggregation induced by the fungal infection is triggered by TXB2via a Ca2+ signal through a PG receptor.

Light Chain LC and TAT-EGFP-HCS of Botulinum Toxin Expression and Biological Function in vitro and in vivo

2019 ◽  
Vol 16 (3) ◽  
pp. 175-180
Author(s):  
Fengjin Hao ◽  
Yueqin Feng ◽  
Yifu Guan
Keyword(s):  
Biological Activity ◽  
Botulinum Toxin ◽  
Cell Membrane ◽  
Western Blot ◽  
Biological Function ◽  
C6 Cells ◽  
Green Fluorescence ◽  
Bv2 Cells

Objective: To verify whether the botulinum toxin heavy chain HCS has specific neuronal targeting function and to confirm whether TAT-EGFP-LC has hydrolyzable SNAP-25 and has transmembrane biological activity. Methods: We constructed the pET-28a-TAT-EGFP-HCS/LC plasmid. After the plasmid is expressed and purified, we co-cultured it with nerve cells or tumors. In addition, we used Western-Blot to identify whether protein LC and TAT-EGFP-LC can digest the protein SNAP-25. Results: Fluorescence imaging showed that PC12, BV2, C6 and HeLa cells all showed green fluorescence, and TAT-EGFP-HCS had the strongest fluorescence. Moreover, TAT-EGFP-LC can hydrolyze intracellular SNAP-25 in PC12 cells, C6 cells, BV2 cells and HeLa, whereas LC alone cannot. In addition, the in vivo protein TAT-EGFP-HCS can penetrate the blood-brain barrier and enter mouse brain tissue. Conclusion: TAT-EGFP-HSC expressed in vitro has neural guidance function and can carry large proteins across the cell membrane without influencing the biological activity.

scholarly journals The growth response of rice (Oryza sativa L. var. FARO 44) in vitro after inoculation with bacterial isolates from a typical ferruginous ultisol

2021 ◽  
Vol 45 (1) ◽  
Author(s):  
Musa Saheed Ibrahim ◽  
Beckley Ikhajiagbe
Keyword(s):  
16S Rrna ◽  
Bacillus Cereus ◽  
Proteus Mirabilis ◽  
Growth Response ◽  
Gene Sequencing ◽  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
Rice Seedlings ◽  
Rrna Gene Sequencing

Abstract Background Rice forms a significant portion of food consumed in most household worldwide. Rice production has been hampered by soil factors such as ferruginousity which has limited phosphorus availability; an important mineral component for the growth and yield of rice. The presence of phosphate-solubilizing bacteria (PSB) in soils has been reported to enhance phosphate availability. In view of this, the present study employed three bacteria species (BCAC2, EMBF2 and BCAF1) that were previously isolated and proved P solubilization capacities as inocula to investigate the growth response of rice germinants in an in vitro setup. The bacteria isolates were first identified using 16S rRNA gene sequencing and then applied as inoculum. The inolula were prepared in three concentrations (10, 7.5 and 5.0 ml) following McFarland standard. Viable rice (var. FARO 44) seeds were sown in petri dishes and then inoculated with the three inocula at the different concentrations. The setup was studied for 28 days. Results 16S rRNA gene sequencing identified the isolates as: isolate BCAC2= Bacillus cereus strain GGBSU-1, isolate BCAF1= Proteus mirabilis strain TL14-1 and isolate EMBF2= Klebsiella variicola strain AUH-KAM-9. Significant improvement in rice germination, morphology, physiology and biomass parameters in the bacteria-inoculated setups was observed compared to the control. Germination percentage after 4 days was 100 % in the inoculated rice germinants compared to 65% in the control (NiS). Similarly, inoculation with the test isolates enhanced water-use efficiency by over 40%. The rice seedlings inoculated with Bacillus cereus strain GGBSU-1 (BiS) showed no signs of chlorosis and necrosis throughout the study period as against those inoculated with Proteus mirabilis strain TL14-1 (PiS) and Klebsiella variicola strain AUH-KAM-9 (KiS). Significant increase in chlorophyll-a, chlorophyll-b and alpha amylase was observed in the rice seedlings inoculated with BiS as against the NiS. Conclusion Inoculating rice seeds with Bacillus cereus strain GGBSU-1, Proteus mirabilis strain TL14-1 and Klebsiella variicola strain AUH-KAM-9 in an in vitro media significantly improved growth parameters of the test plant. Bacillus cereus strain GGBSU-1 showed higher efficiency due to a more improved growth properties observed.

scholarly journals GPR37 promotes the malignancy of lung adenocarcinoma via TGF-β/Smad pathway

Open Medicine ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 024-032
Author(s):  
Jian Wang ◽  
Min Xu ◽  
Dan-Dan Li ◽  
Wujikenayi Abudukelimu ◽  
Xiu-Hong Zhou
Keyword(s):  
Lung Adenocarcinoma ◽  
Biological Function ◽  
Migration And Invasion ◽  
Loss Of Function ◽  
Malignant Phenotype ◽  
Smad Pathway ◽  
Smad3 Phosphorylation ◽  
Poor Outcomes ◽  
Tgf Β1

AbstractThis paper aimed to research the function and in-depth mechanism of GPR37 in lung adenocarcinoma (LUAD). Herein, based on TCGA and Oncomine databases, we revealed that GPR37 was expressed at high levels in LUAD, and upregulation of GPR37 was related to the poor outcomes. Furthermore, biological function experiments in vitro were utilized to assess whether GPR37 impacts malignant phenotype of LUAD cells. Gain- or loss-of-function assays indicated that the upregulation of GPR37 contributed to improving the proliferation, migration, and invasion of LUAD cells in vitro, while knockdown of GPR37 can inhibit the malignant biological behaviors. Then, we found that depletion of GPR37 resulted in a decrease in the expression of TGF-β1 as well as the extents of Smad2 and Smad3 phosphorylation, while overexpression of GPR37 presented opposite outcomes. Altogether, our findings indicated that GPR37 is a potential oncogene of LUAD, and its promoting effects on the malignant progression of LUAD may be realized via TGF-β/Smad pathway.

scholarly journals Identification of Putative Virulence Genes by DNA Methylation Studies in the Cereal Pathogen Fusarium graminearum

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1192
Author(s):  
Francesco Tini ◽  
Giovanni Beccari ◽  
Gianpiero Marconi ◽  
Andrea Porceddu ◽  
Micheal Sulyok ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Fusarium Graminearum ◽  
Environmental Changes ◽  
Virulent Strain ◽  
Fungal Virulence ◽  
Wheat Seedlings ◽  
Wide Range ◽  
Conidia Production ◽  
Natural Hosts

DNA methylation mediates organisms’ adaptations to environmental changes in a wide range of species. We investigated if a such a strategy is also adopted by Fusarium graminearum in regulating virulence toward its natural hosts. A virulent strain of this fungus was consecutively sub-cultured for 50 times (once a week) on potato dextrose agar. To assess the effect of subculturing on virulence, wheat seedlings and heads (cv. A416) were inoculated with subcultures (SC) 1, 23, and 50. SC50 was also used to re-infect (three times) wheat heads (SC50×3) to restore virulence. In vitro conidia production, colonies growth and secondary metabolites production were also determined for SC1, SC23, SC50, and SC50×3. Seedling stem base and head assays revealed a virulence decline of all subcultures, whereas virulence was restored in SC50×3. The same trend was observed in conidia production. The DNA isolated from SC50 and SC50×3 was subject to a methylation content-sensitive enzyme and double-digest, restriction-site-associated DNA technique (ddRAD-MCSeEd). DNA methylation analysis indicated 1024 genes, whose methylation levels changed in response to the inoculation on a healthy host after subculturing. Several of these genes are already known to be involved in virulence by functional analysis. These results demonstrate that the physiological shifts following sub-culturing have an impact on genomic DNA methylation levels and suggest that the ddRAD-MCSeEd approach can be an important tool for detecting genes potentially related to fungal virulence.

scholarly journals Exploitation of conserved eukaryotic host cell farnesylation machinery by an F-box effector of Legionella pneumophila

2010 ◽  
Vol 207 (8) ◽  
pp. 1713-1726 ◽  
Author(s):  
Christopher T.D. Price ◽  
Tasneem Al-Quadan ◽  
Marina Santic ◽  
Snake C. Jones ◽  
Yousef Abu Kwaik
Keyword(s):  
Legionella Pneumophila ◽  
Biological Function ◽  
Host Cells ◽  
Dependent Manner ◽  
Protein Farnesyltransferase ◽  
Type Iv ◽  
Eukaryotic Proteins ◽  
Bacterial Effectors

Farnesylation involves covalent linkage of eukaryotic proteins to a lipid moiety to anchor them into membranes, which is essential for the biological function of Ras and other proteins. A large cadre of bacterial effectors is injected into host cells by intravacuolar pathogens through elaborate type III–VII translocation machineries, and many of these effectors are incorporated into the pathogen-containing vacuolar membrane by unknown mechanisms. The Dot/Icm type IV secretion system of Legionella pneumophila injects into host cells the F-box effector Ankyrin B (AnkB), which functions as platforms for the docking of polyubiquitinated proteins to the Legionella-containing vacuole (LCV) to enable intravacuolar proliferation in macrophages and amoeba. We show that farnesylation of AnkB is indispensable for its anchoring to the cytosolic face of the LCV membrane, for its biological function within macrophages and Dictyostelium discoideum, and for intrapulmonary proliferation in mice. Remarkably, the protein farnesyltransferase, RCE-1 (Ras-converting enzyme-1), and isoprenyl cysteine carboxyl methyltransferase host farnesylation enzymes are recruited to the LCV in a Dot/Icm-dependent manner and are essential for the biological function of AnkB. In conclusion, this study shows novel localized recruitment of the host farnesylation machinery and its anchoring of an F-box effector to the LCV membrane, and this is essential for biological function in vitro and in vivo.

scholarly journals Resistance-related physiological response of rice leaves to the compound stress of enhanced UV-B radiation and Magnaporthe oryzae

2018 ◽  
Vol 13 (1) ◽  
pp. 321-328 ◽  
Author(s):  
Yongmei He ◽  
Xiang Li ◽  
Fangdong Zhan ◽  
Chunmei Xie ◽  
Yanqun Zu ◽  
...  
Keyword(s):  
Magnaporthe Oryzae ◽  
Physiological Response ◽  
Rice Leaves

scholarly journals Induced Expression of Sarcotoxin IA Enhanced Host Resistance Against Both Bacterial and Fungal Pathogens in Transgenic Tobacco

2000 ◽  
Vol 13 (8) ◽  
pp. 860-868 ◽  
Author(s):  
Ichiro Mitsuhara ◽  
Hiroki Matsufuru ◽  
Masahiro Ohshima ◽  
Hisatoshi Kaku ◽  
Yuki Nakajima ◽  
...  
Keyword(s):  
Fungal Infection ◽  
Transgenic Tobacco ◽  
Pseudomonas Syringae ◽  
Host Resistance ◽  
Fungal Pathogens ◽  
Erwinia Carotovora ◽  
Induced Expression ◽  
Sarcotoxin Ia ◽  
Resistance To Infection

We demonstrate here that induced expression of sarcotoxin IA, a bactericidal peptide from Sarcophaga peregrina, enhanced the resistance of transgenic tobacco plants to both bacterial and fungal pathogens. The peptide was produced with a modified PR1a promoter, which is further activated by salicylic acid treatment and necrotic lesion formation by pathogen infection. Host resistance to infection of bacteria Erwinia carotovora subsp. carotovora and Pseudomonas syringae pv. tabaci was shown to be dependent on the amounts of sarcotoxin IA expressed. Since we found antifungal activity of the peptide in vitro, transgenic seedlings were also inoculated with fungal pathogens Rhizoctonia solani and Pythium aphanidermatum. Transgenic plants expressing higher levels of sarcotoxin were able to withstand fungal infection and remained healthy even after 4 weeks, while control plants were dead by fungal infection after 2 weeks.

scholarly journals ANTIFUNGAL POTENTIAL OF ETHANOL EXTRACTS OF ALLIUM SATIVUM AND ALLIUM AMPELOPRASUM

2017 ◽  
Vol 10 (4) ◽  
pp. 207
Author(s):  
Shahid Khan ◽  
Neeta Raj Sharma
Keyword(s):  
Growth Inhibition ◽  
Causative Agent ◽  
Magnaporthe Oryzae ◽  
Allium Sativum ◽  
Microtiter Plate ◽  
Blast Disease ◽  
Allium Ampeloprasum ◽  
Antifungal Potential ◽  
Ethanol Extracts

Objective: In vitro analysis of Allium sativum and Allium ampeloprasum was performed to evaluate their antifungal potential against Alternaria triticina (ITCC 5496), causative agent of leaf blight in wheat and Magnaporthe oryzae (ITCC 6808), causative agent of blast disease in rice.Methods: Ethanol extracts of A. ampeloprasum and A. sativum were prepared by crushing their bulb in liquid nitrogen and then immersing them in 90% ethanol and 100% ethanol separately. The antifungal activity test was determined by quantitative assay using 96-well microtiter plate and results were statistically analyzed using GraphPad Prism v. 5.03.Results: A. triticina and M. oryzae showed above 90% and 95% growth inhibition, respectively against the ethanol extracts of A. ampeloprasum. Conversely, growth inhibition of either fungus remained mostly below 35% against ethanol extracts of A. sativum at all tested concentrations.Conclusion: Ethanol extracts of A. ampeloprasum have relatively higher antifungal potential than ethanol extracts of A. sativum and could be considered as a natural alternative to chemical fungicides.Keywords: Allium sativum, Allium ampeloprasum, Alternaria triticina, Magnaporthe oryzae.

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