colony morphology
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Author(s):  
Yujie Xiao ◽  
Qingyuan Liang ◽  
Meina He ◽  
Nianqi Wu ◽  
Liang Nie ◽  
...  

Exopolysaccharides (EPSs) Pea is essential for wrinkly colony morphology, pellicle formation, and robust biofilm production in Pseudomonas putida . The second messenger cyclic diguanylate monophosphate (c-di-GMP) induces wrinkly colony morphology in P. putida through unknown mechanism(s). Herein, we found that c-di-GMP modulated wrinkly colony morphology via regulating expression of eppA ( PP_5586 ), a small individually transcribed gene with 177 base pairs, and this gene was adjacent to the upstream of pea cluster. Phenotype observation revealed that eppA was essential for Pea-dependent phenotypes. The deletion of eppA led to smooth colony morphology and impaired biofilm, which was analogous to the phenotypes with the loss of the entire pea operon. EppA expression was positively regulated by c-di-GMP via the transcriptional effector FleQ, and eppA was essential for the c-di-GMP-induced wrinkly colony morphology. Structure prediction results implied that EppA had two transmembrane regions, and Western blot revealed that EppA was located on cell membrane. Transcriptomic analysis indicated that EppA had no significant effect on transcriptomic profile of P. putida . Bacterial two-hybrid (BTH) assay suggested that there was no direct interaction between EppA and the proteins in pea cluster and adjacent operons. Overall, these findings reveal that EppA is essential for Pea-dependent phenotypes, and that c-di-GMP modulates Pea-dependent phenotypes via regulating eppA expression in P. putida . IMPORTANCE Microbe-secreted EPSs are high molecular weight polysaccharides that have the potential to be used as industrially important biomaterials. The EPS Pea in P. putida is essential for wrinkly colony morphology and pellicle formation. Here, we identified a function-unknown protein EppA, which was also essential for Pea-dependent wrinkly colony morphology and pellicle formation, and EppA was probably involved in Pea secretion. Meanwhile, our results indicated that the second messenger c-di-GMP positively regulated the expression of EppA, resulting in Pea-dependent wrinkly colony morphology. Our results reveal the relationship of c-di-GMP, EppA, and Pea-dependent phenotypes, and provide possible pathway to construct genetically engineered strain for high Pea production.


2021 ◽  
Author(s):  
◽  
Gustav Kessel

<p><b>Octocorals are a diverse group of sessile, colonial, filter-feeding anthozoan cnidarians, which form significant components of benthic marine communities worldwide. Globally, the most critical hurdle to the effective management of octocorals in the face of increasing anthropogenic pressure is the poor state of their species-level taxonomy, which hinders understanding of their biodiversity. New Zealand’s octocoral assemblage is among the most diverse of any country and is characterised by high levels of endemism, yet over half of its octocoral species remain undescribed. While progress is being made, this has focussed almost exclusively on protected deep-sea gorgonian octocorals.</b></p> <p>Unprotected coastal soft corals are less studied in New Zealand. This includes the endemic Alcyonium aurantiacum Quoy and Gaimard, 1833. Multiple, morphologically diverse forms have been attributed to this species. Here, the taxonomic status of A. aurantiacum is reviewed, and its phylogenetic relationships are examined using molecular data (nuclear 28S and mitochondrial MutS genes), which is compared to morphology in an integrative approach. As a result, evidence for two new, endemic genera and ten new species is presented. Alcyonium aurantiacum is referred to Kotatea gen. n. (as K. aurantiaca comb. n.), which contains seven additional new species. A second genus, Ushanaia gen. n., contains three new species.</p> <p>Of the new taxa described herein, K. aurantiaca and K. lobata sp. n. are the most commonly encountered and widespread, yet little is known regarding their biology. Both species co-occur in their natural habitat, could not be differentiated genetically with the tools used here, and can be difficult to distinguish without microscopic sclerite examinations. To facilitate the identification of these two similar species by non-taxonomists, a statistical model was developed that can discriminate them with up to 90% accuracy using easily obtainable measurements of gross colony morphology. Relationships between colony morphology and depth are also examined.</p> <p>Considering the difficulties associated with species discrimination among octocorals, a literature survey was conducted to review the use of integrative taxonomy in this group since the start of the 21st century, focusing particularly on morpho-molecular data comparisons. This revealed that, while description rates at family, genus, and species levels over the last twenty-one years rank among the highest ever, integrative techniques have been applied unevenly across taxonomic groups and geographic regions and overall remain a minority compared to taxonomic research based solely on morphology. Implementation of the integrative approach is increasing, however, as are the per-annum number of taxonomic publications and the total pool of authors associated with these publications.</p> <p>It is hoped that the research presented herein can contribute to ongoing global efforts of revising octocoral systematics and that the examination of integrative practices in octocoral taxonomy will serve as a baseline against which future taxonomic progress can be compared and promoted. For New Zealand specifically, elucidating the taxonomy and variability of these endemic taxa will enable aspects such as their contribution to ecosystem functioning and management needs to be examined accurately for the first time, which in turn may lead to their recognition as organisms worthy of legal protection.</p>


2021 ◽  
Author(s):  
◽  
Gustav Kessel

<p><b>Octocorals are a diverse group of sessile, colonial, filter-feeding anthozoan cnidarians, which form significant components of benthic marine communities worldwide. Globally, the most critical hurdle to the effective management of octocorals in the face of increasing anthropogenic pressure is the poor state of their species-level taxonomy, which hinders understanding of their biodiversity. New Zealand’s octocoral assemblage is among the most diverse of any country and is characterised by high levels of endemism, yet over half of its octocoral species remain undescribed. While progress is being made, this has focussed almost exclusively on protected deep-sea gorgonian octocorals.</b></p> <p>Unprotected coastal soft corals are less studied in New Zealand. This includes the endemic Alcyonium aurantiacum Quoy and Gaimard, 1833. Multiple, morphologically diverse forms have been attributed to this species. Here, the taxonomic status of A. aurantiacum is reviewed, and its phylogenetic relationships are examined using molecular data (nuclear 28S and mitochondrial MutS genes), which is compared to morphology in an integrative approach. As a result, evidence for two new, endemic genera and ten new species is presented. Alcyonium aurantiacum is referred to Kotatea gen. n. (as K. aurantiaca comb. n.), which contains seven additional new species. A second genus, Ushanaia gen. n., contains three new species.</p> <p>Of the new taxa described herein, K. aurantiaca and K. lobata sp. n. are the most commonly encountered and widespread, yet little is known regarding their biology. Both species co-occur in their natural habitat, could not be differentiated genetically with the tools used here, and can be difficult to distinguish without microscopic sclerite examinations. To facilitate the identification of these two similar species by non-taxonomists, a statistical model was developed that can discriminate them with up to 90% accuracy using easily obtainable measurements of gross colony morphology. Relationships between colony morphology and depth are also examined.</p> <p>Considering the difficulties associated with species discrimination among octocorals, a literature survey was conducted to review the use of integrative taxonomy in this group since the start of the 21st century, focusing particularly on morpho-molecular data comparisons. This revealed that, while description rates at family, genus, and species levels over the last twenty-one years rank among the highest ever, integrative techniques have been applied unevenly across taxonomic groups and geographic regions and overall remain a minority compared to taxonomic research based solely on morphology. Implementation of the integrative approach is increasing, however, as are the per-annum number of taxonomic publications and the total pool of authors associated with these publications.</p> <p>It is hoped that the research presented herein can contribute to ongoing global efforts of revising octocoral systematics and that the examination of integrative practices in octocoral taxonomy will serve as a baseline against which future taxonomic progress can be compared and promoted. For New Zealand specifically, elucidating the taxonomy and variability of these endemic taxa will enable aspects such as their contribution to ecosystem functioning and management needs to be examined accurately for the first time, which in turn may lead to their recognition as organisms worthy of legal protection.</p>


2021 ◽  
Author(s):  
Grace I Borlee ◽  
Mihnea R. Mangalea ◽  
Kevin H. Martin ◽  
Brooke A. Plumley ◽  
Samuel J. Golon ◽  
...  

The regulation and production of secondary metabolites during biofilm growth of Burkholderia spp. is not well understood. To learn more about the crucial role and regulatory control of cryptic molecules produced during biofilm growth, we disrupted c-di-GMP signaling in Burkholderia pseudomallei, a soil-borne bacterial saprophyte and the etiologic agent of melioidosis. Our approach to these studies combined transcriptional profiling with genetic deletions that targeted key c-di-GMP regulatory components to characterize responses to changes in temperature. Mutational analyses and conditional expression studies of c-di-GMP genes demonstrates their contribution to phenotypes such as biofilm formation, colony morphology, motility, and expression of secondary metabolite biosynthesis when grown as a biofilm at different temperatures. RNA-seq analysis was performed at varying temperatures in a ΔII2523 mutant background that is responsive to temperature alterations resulting in hypo- and hyper- biofilm forming phenotypes. Differential regulation of genes was observed for polysaccharide biosynthesis, secretion systems, and nonribosomal peptide and polyketide synthase (NRPS/PKS) clusters in response to temperature changes. Deletion mutations of biosynthetic gene clusters (BGCs) clusters 2, 11, 14 (syrbactin), and 15 (malleipeptin) in wild-type and ΔII2523 backgrounds also reveals the contribution of these BGCs to biofilm formation and colony morphology in addition to inhibition of Bacillus subtilis and Rhizoctonia solani. Our findings suggest that II2523 impacts the regulation of genes that contribute to biofilm formation and competition. Characterization of cryptic BGCs under differing environmental conditions will allow for a better understanding of the role of secondary metabolites in the context of biofilm formation and microbe-microbe interactions.


2021 ◽  
Author(s):  
Yuan Xie ◽  
Zhifang Wang ◽  
Ke Li ◽  
Dongwei Liu ◽  
Yifan Jia ◽  
...  

Fusarium pseudograminearum is a phytopathogen that causes wheat crown rot disease worldwide. Fusarium pseudograminearum megabirnavirus 1 (FpgMBV1) was isolated from the hypovirulent strain FC136-2A of F. pseudograminearum as a novel dsRNA mycovirus belonging to the family Megabirnaviridae. Here we examined the effects of FpgMBV1 on colony morphology and pathogenicity of F. pseudograminearum. Through hyphal tip culture, we obtained virus-free progeny of strain FC136-2A, referred to as FC136-2A-V-.FpgMBV1 was transferred horizontally to another virus-free strain, WZ-8A-HygR-V-. The progeny that obtained through horizontal transfer was referred to as WZ-8A-HygR-V+. Colony morphology was similar between the FpgMBV1-positive and -negative strains. The ability to penetrate cellophane in vitro was lost and pathogenicity on wheat plants was reduced significantly in the FpgMBV1-positive strains relative to the FpgMBV1-negative strains. Microscopic observations showed a 6-h delay in the formation of appressoria-like structures in FC136-2A relative to FC136-2A-V-. And mycelium extension was significantly longer in wheat coleoptiles infected by WZ-8A-HygR-V- than in that infected by WZ-8A-HygR-V+ at 12 and 20 hours after inoculation (HAI). In addition, expression of five genes that encode cell wall-degrading enzymes differed significantly between FpgMBV1-positive and -negative strains at 12 and 20 HAI during early infection of wheat cells by conidia. This study provides evidence for the hypovirulence effect of FpgMBV1 on F. pseudograminearum and suggests that the underlying mechanism involves unsuccessful early infection and perhaps cell wall degradation.


Author(s):  
Ülkü Karatekeli ◽  
Beytullah Kenar

Background: Contagious agalactia causes significant economic losses. The aim of this study is to investigate the presence of contagious agalactia disease in cities of Isparta and Afyonkarahisar, Turkey. Methods: The study includes 45.500 animals in 220 ovine enterprises and samples were taken from those suspected of contagious agalactia disease. 202 animals in the 21 ovine enterprises comprised of 139 goats, 56 sheep, 3 kid goats, 2 goats, 2 lambs in total suspected of the disease were sampled. A total of 289 samples were collected, including 91 milk samples, 28 nasal swabs, 101 eye swabs, 8 joint fluids and 61 ear swabs. The isolates obtained after incubation were identified with polymerase chain reaction by using specific primers to assess film and spot formation, glucose fermentation, growth inhibition tests. Result: Three Mycoplasma spp. isolates obtained from 28 nasal swabs turned out to be negative for M. agalactiae after PCR analysis. Colony morphology, biochemical tests and growth inhibition tests revealed that one agent was M. arginine and the two factors were identified as M. ovipneumoniae with centerless colony morphology. The obtained results were confirmed with the polymerase chain reaction. None of the four factors causing contagious agalactia were isolated and identified.


2021 ◽  
Vol 7 (11) ◽  
pp. 107297-107313
Author(s):  
Thaissa Cunha De Oliveira ◽  
Cassiane Minelli-Oliveira ◽  
Nadionara Costa Menezes ◽  
Suziane Pinto Rodrigues ◽  
José Carlos Ipuchima Da Silva ◽  
...  

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 785-785
Author(s):  
Pamela J. Sung ◽  
Simone Sidoli ◽  
Simone S. Riedel ◽  
Katarzyna Kulej ◽  
Hongbo Xie ◽  
...  

Abstract Internal tandem duplication mutations in the Fms-like tyrosine kinase 3 (FLT3-ITD) are frequently recurring in AML and confer a poor prognosis. FLT3 inhibitors (FLT3i) such as gilteritinib are efficacious in relapsed AML. Clinical responses to FLT3i include myeloid differentiation of the FLT3-ITD clone in about 50% of patients. How FLT3i induce this response in a subset of patients is unknown. The FLT3i-induced differentiation response seen in clinical trials has not previously been demonstrated in animal models. We modeled FLT3i-induced differentiation in murine Flt3 ITD/ITDDnmt3a -/- AML model (Meyer et al., Cancer Discovery, 2016). Treatment with FLT3i in vitro accelerated differentiation of cKIT+ leukemic splenocytes as assessed by colony morphology in serial re-plating assays. To characterize the differentiation response in vivo, we transplanted CD45.2+ leukemic splenocytes from moribund mice into sub-lethally irradiated healthy congenic CD45.1+ mice. After confirmation of engraftment at 2 weeks post-irradiation, mice were treated with vehicle or gilteritinib for 4 weeks. Animals treated with gilteritinib demonstrated increased neutrophil and decreased stem/progenitor cell populations, recapitulating the clinically observed increase in granulocytic differentiation of the FLT3-ITD clone. We next sought to understand the molecular mechanism of FLT3i-induced differentiation. We used a proteomic-based screen in a human AML cell line treated with FLT3i to identify novel targets of FLT3-ITD that could be potential mediators of the differentiation response. We identified downregulation of Enhancer of Zeste Homolog 2 (EZH2), the catalytic component of the Polycomb Repressive Complex 2 (PRC2). EZH2 and PRC2 were previously shown to be required for leukemic maintenance in mouse models of MLL-AF9 AML. We treated murine Flt3 ITD/ITDDnmt3a -/- cKIT+ leukemic splenocytes with FLT3i or the EZH1/2 inhibitor (EZH1/2i). Both promoted myeloid differentiation to similar degrees as assessed by colony morphology in this model. We hypothesized that FLT3-ITD regulates EZH2 to maintain leukemia cells in a stem/progenitor cell state. We, therefore, characterized the effect of FLT3i on PRC2 in more detail. We confirmed that FLT3i decreases EZH2 protein levels in FLT3-ITD cell lines and primary human AML within 24 hours of treatment as suggested by our proteomic data (Figure 1A-B). We found that the mechanism of EZH2 downregulation is complex with both transcriptional effects and a decrease in EZH2 protein half-life. ChIP-Seq for H3K27me3 demonstrated decreased peaks at the transcription start sites of PRC2 target genes (Figure 1C). RNA-Seq gene expression profiles of FLT3i- and EZH1/2i-treated human AML cells overlapped at 253 differentially expressed genes (Figure 1D). Critically, both FLT3i and EZH1/2i expression profiles enriched in differentiated myeloid cell gene signatures. Overall, we found that EZH2 is a novel, unexpected, and clinically relevant target of FLT3-ITD. Our data suggest that reduced EZH2 activity following FLT3 inhibition promotes myeloid differentiation of FLT3-ITD leukemic cells, providing a mechanistic explanation for the FLT3i-induced differentiation response seen in patients. These data demonstrate that FLT3-ITD has at least two functions in leukemogenesis, the well described activation of signaling pathways, and second, a previously undefined, regulation of PRC2 to maintain a myeloid stem cell state. Our results may lead to improved approaches to therapy for FLT3 mutated AML. Figure 1 Figure 1. Disclosures Bernt: Syndax: Research Funding; Merck: Other: Spouse is an employee of Merck.. Carroll: Incyte Pharmaceuticals: Research Funding; Janssen Pharmaceutical: Consultancy.


Plant Disease ◽  
2021 ◽  
Author(s):  
Georgios Makris ◽  
Solonas Solonos ◽  
Marios Christodoulou ◽  
Loukas Kanetis

In June 2017, three vineyards were surveyed in the regions of Droushia (30-year-old, cv Mavro), Ineia (50-year-old, cv Xynisteri), and Lemona (15-year-old, cv Carignan) at the province of Paphos, Cyprus, with dieback incidence of 22%, 32%, and 14%, respectively. More specifically, affected grapevines exhibited severe dieback symptoms in spur and cordon positions, related to perennial cankers and internal brown discoloration. Thirty symptomatic samples, were surface-sterilized (95% ethanol) and wood chips were plated on potato dextrose agar (PDA), amended with streptomycin (500 μg/ml) at 25 °C for 3-5 days. Based on colony morphology (white to creamy color, with sparse aerial mycelium) and conidia production, nine Diaporthe-like isolates were obtained. For species identification, the internal transcribed spacer (ITS) region and β-tubulin (BT) genes were amplified using the primer pairs ITS1/ITS4 and Bt2a/Bt2b, respectively (Úrbez-Torres et al. 2008). Sequences of the isolates P101b, P114c, and P289a revealed >99.8% homology to NCBI voucher specimens of Diaporthe foeniculina (Sacc.) Udayanga & Castl. (ITS: CBS111553, MH050434; ΒΤ: KY511368, KF778966), and were deposited in the GeneBank (ITS: MT735646, MT737289, MT737287; BT: MT903969, MT903970, MT903971). Thus, 8.3% of the collected isolates (3 of 36) were identified as D. foeniculina, while the rest Diaporthe-like isolates were identified as D. ampelina. D. foeniculina isolates were also transferred on 2% water agar with sterile pine needles under a 12h/12h near-ultraviolet, light/darkness regime, at 25 °C, to induce sporulation (Guarnaccia and Crous 2017). Two weeks later, microscopic observations revealed dark brown to black, globose to sub-globose, ostiolate pycnidia (n = 30) 291 to 897 μm (595 ± 173) x 192 to 655 μm (364 ± 113) containing hyaline, unbranched conidiophores, bearing alpha‐ and beta‐conidia in the form of yellowish cirri. Alpha-conidia were aseptate, hyaline, ovate to ellipsoidal, ranging (n=100) from 5.6 to 9.9 μm (7.5 ± 0.8) x 1.9 to 3.3 μm (2.7 ± 0.3). Beta-conidia were abundant, aseptate, hyaline, filiform, slightly curved (n = 100) from 22.4 to 35.3 μm (28.1 ± 2.5) x 1.2 to 2.3 μm (1.6 ± 0.2) (Udayanga et al. 2014). Pathogenicity tests were conducted with isolates P101b and P289a under greenhouse conditions (24-32 ⁰C, 70% RH). Ten 1-year-old rooted canes cv Mavro were inoculated with 4 mm mycelium plugs from actively growing cultures into wounds made by drilling between two internodes at the middle of the trunk. The same number of cuttings were inoculated with sterile PDA plugs, sealed with Vaseline, and wrapped with parafilm, serving as controls. Seven months later, all inoculated cuttings developed brownish wood discolorations (average 39 ± 13 mm), similar to naturally infected plants. No symptoms were observed in the controls. Successful re-isolations were made only from the inoculated cuttings and confirmed by colony morphology. Previously, D. foeniculina (as D. neotheicola) has been reported as grapevine wood saprophyte (Úrbez-Torres et al. 2014). It has also been reported to cause shoot canker and dieback in numerous hosts, including almond, avocado, citrus, and sweet chestnut (Annesi et al. 2016; Guarnaccia and Crous 2017; Diogo et al. 2010; Mathioudakis et al. 2020). This is the first record of D. foeniculina associated with grapevine trunk diseases (GTDs) in Cyprus. However, its relative importance as the causal agent of GTDs remains to be further investigated.


2021 ◽  
Author(s):  
Kabita Gurung ◽  
Khashti Dasila ◽  
Bahadur Singh Bamaniya ◽  
Anita Pandey ◽  
Laxuman Sharma ◽  
...  

Abstract Large cardamom (Amommum subulatum Roxb.) a high valued spice crop grown in Sikkim Himalaya is now facing a devastating leaf blight disease that has brought down the yield drastically. Present study was focused on identification of this major fungal pathogen based on the morphological and molecular characterization. During this study infected leaves of large cardamom with blighted appearance were collected from all the four districts of Sikkim. The pathogen was isolated using Potato Dextrose Agar (PDA) medium, incubated at 25°C. The mycelium was septate, hyaline, and 2-4 µm wide. The conidiospores were cylindrical with both ends rounded, sometimes oblong. Length and breadth were 11-12 µm and 3-4 µm, respectively. On the basis colony morphology, growth and microscopic observations, out of the total 48 samples studied Colletotrichum sp. was identified from 14 samples. Based on phylogenetic analysis of the ITS4, ITS5 and ApMAT genes and phenotypic characters (colony morphology, microscopic features) the isolate (No. LC05) isolated from the sample collected from the village Assam Linzey, East Sikkim showed 100% homology with Colletotrichum fructicola from NCBI database. The pathogenicity of C. fructicola was also confirmed during the study. The fungal culture has been deposited at the NFCCI-ARI, Pune with an accession number NFCCI 4542 and the sequences have been deposited in NCBI GenBank with accession number (ITS) MN710587, (ApMAT) MW348934 respectively. To the best of our knowledge this is the first report of C. fructicola causing blight disease of large cardamom. Also the finding is very important to improve the disease control strategies of this high valued cash crop.


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