The agent associated with blue dwarf disease in wheat represents a new phytoplasma taxon, ‘Candidatus Phytoplasma tritici’

Author(s):  
Yan Zhao ◽  
Wei Wei ◽  
Robert E. Davis ◽  
Ing-Ming Lee ◽  
Kristi D. Bottner-Parker

Wheat blue dwarf (WBD) is one of the most economically damaging cereal crop diseases in northwestern PR China. The agent associated with the WBD disease is a phytoplasma affiliated with the aster yellows (AY) group, subgroup C (16SrI-C). Since phytoplasma strains within the AY group are ecologically and genetically diverse, it has been conceived that the AY phytoplasma group may consist of more than one species. This communication presents evidence to demonstrate that, while each of the two 16 rRNA genes of the WBD phytoplasma shares >97.5 % sequence similarity with that of the ‘Candidatus Phytoplasma asteris’ reference strain, the WBD phytoplasma clearly represents an ecologically separated lineage: the WBD phytoplasma not only has its unique transmitting vector (Psammotettix striatus) but also elicits a distinctive symptom in its predominant plant host (wheat). In addition, the WBD phytoplasma possesses molecular characteristics that further manifest its significant divergence from ‘Ca. P. asteris’. Such molecular characteristics include lineage-specific antigenic membrane proteins and a lower than 95 % genome-wide average nucleotide identity score with ‘Ca. P. asteris’. These ecological, molecular and genomic evidences justify the recognition of the WBD phytoplasma as a novel taxon, ‘Candidatus Phytoplasma tritici’.

Author(s):  
Jiao Huang ◽  
Ying Huang

A novel filamentous Actinobacterium, designated strain FXJ1.1311T, was isolated from soil collected in Ngari (Ali) Prefecture, Qinghai-Tibet Plateau, western PR China. The strain showed antimicrobial activity against Gram-positive bacteria and Fusarium oxysporum. Results of phylogenetic analysis based on 16S rRNA gene sequences indicated that strain FXJ1.1311T belonged to the genus Lentzea and showed the highest sequence similarity to Lentzea guizhouensis DHS C013T (98.04%). Morphological and chemotaxonomic characteristics supported its assignment to the genus Lentzea . The genome-wide average nucleotide identity between strain FXJ1.1311T and L. guizhouensis DHS C013T as well as other Lentzea type strains was <82.2 %. Strain FXJ1.1311T also formed a monophyletic line distinct from the known Lentzea species in the phylogenomic tree. In addition, physiological and chemotaxonomic characteristics allowed phenotypic differentiation of the novel strain from L. guizhouensis . Based on the evidence presented here, strain FXJ1.1311T represents a novel species of the genus Lentzea , for which the name Lentzea tibetensis sp. nov. is proposed. The type strain is FXJ1.1311T (=CGMCC 4.7383T=DSM 104975T).


Biophysica ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 1-14
Author(s):  
João Victor de Souza ◽  
Piotr Zaborniak ◽  
Sylvia Reznikov ◽  
Matthew Kondal ◽  
Ruidi Zhu ◽  
...  

Per-Arnt-Sim (PAS) domains are evolutionarily-conserved regions found in proteins in all living systems, involved in transcriptional regulation and the response to hypoxic and xenobiotic stress. Despite having low primary sequence similarity, they show an impressively high structural conservation. Nonetheless, understanding the underlying mechanisms that drive the biological function of the PAS domains remains elusive. In this work, we used molecular dynamics simulations and bioinformatics tools in order the investigate the molecular characteristics that govern the intrinsic dynamics of five PAS-B domains (human AhR receptor, NCOA1, HIF1α, and HIF2α transcription factors, and Drosophila Suzukii (D. Suzukii) juvenile hormone receptor JHR). First, we investigated the effects of different length of N and C terminal regions of the AhR PAS-B domain, showing that truncation of those segments directly affects structural stability and aggregation propensity of the domain. Secondly, using the recently annotated PAS-B located in the methoprene-tolerant protein/juvenile hormone receptor (JHR) from D. Suzukii, we have shown that the mutation of the highly conserved “gatekeeper” tyrosine to phenylalanine (Y322F) does not affect the stability of the domain. Finally, we investigated possible redox-regulation of the AhR PAS-B domain by focusing on the cysteinome residues within PAS-B domains. The cysteines in AhR PAS-B are directly regulating the dynamics of the small molecule ligand-gating loop (residues 305 to 326). In conclusion, we comprehensibly described several molecular features governing the behaviour of PAS-B domains in solution, which may lead to a better understanding of the forces driving their biological functions.


Plants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1692
Author(s):  
Li Gu ◽  
Ting Su ◽  
Ming-Tai An ◽  
Guo-Xiong Hu

Oreocharis esquirolii, a member of Gesneriaceae, is known as Thamnocharis esquirolii, which has been regarded a synonym of the former. The species is endemic to Guizhou, southwestern China, and is evaluated as vulnerable (VU) under the International Union for Conservation of Nature (IUCN) criteria. Until now, the sequence and genome information of O. esquirolii remains unknown. In this study, we assembled and characterized the complete chloroplast (cp) genome of O. esquirolii using Illumina sequencing data for the first time. The total length of the cp genome was 154,069 bp with a typical quadripartite structure consisting of a pair of inverted repeats (IRs) of 25,392 bp separated by a large single copy region (LSC) of 85,156 bp and a small single copy region (SSC) of18,129 bp. The genome comprised 114 unique genes with 80 protein-coding genes, 30 tRNA genes, and four rRNA genes. Thirty-one repeat sequences and 74 simple sequence repeats (SSRs) were identified. Genome alignment across five plastid genomes of Gesneriaceae indicated a high sequence similarity. Four highly variable sites (rps16-trnQ, trnS-trnG, ndhF-rpl32, and ycf 1) were identified. Phylogenetic analysis indicated that O. esquirolii grouped together with O. mileensis, supporting resurrection of the name Oreocharis esquirolii from Thamnocharisesquirolii. The complete cp genome sequence will contribute to further studies in molecular identification, genetic diversity, and phylogeny.


2007 ◽  
Vol 57 (6) ◽  
pp. 1243-1249 ◽  
Author(s):  
Ngoc-Phuc Hua ◽  
Atsuko Kanekiyo ◽  
Katsunori Fujikura ◽  
Hisato Yasuda ◽  
Takeshi Naganuma

Two Gram-positive, rod-shaped, moderately halophilic bacteria were isolated from a deep-sea carbonate rock at a methane cold seep in Kuroshima Knoll, Japan. These bacteria, strains IS-Hb4T and IS-Hb7T, were spore-forming and non-motile. They were able to grow at temperatures as low as 9 °C and hydrostatic pressures up to 30 MPa. Based on high sequence similarity of their 16S rRNA genes to those of type strains of the genus Halobacillus, from 96.4 % (strain IS-Hb7T to Halobacillus halophilus NCIMB 9251T) to 99.4 % (strain IS-Hb4T to Halobacillus dabanensis D-8T), the strains were shown to belong to this genus. DNA–DNA relatedness values of 49.5 % and 1.0–33.0 %, respectively, were determined between strains IS-Hb4T and IS-Hb7T and between these strains and other Halobacillus type strains. Both strains showed the major menaquinone MK7 and l-orn–d-Asp cell-wall peptidoglycan type. Straight-chain C16 : 0, unsaturated C16 : 1 ω7c alcohol and C18 : 1 ω7c and cyclopropane C19 : 0 cyc fatty acids were predominant in both strains. The DNA G+C contents of IS-Hb4T and IS-Hb7T were respectively 43.3 and 42.1 mol%. Physiological and biochemical analyses combined with DNA–DNA hybridization results allowed us to place strains IS-Hb4T (=JCM 14154T=DSM 18394T) and IS-Hb7T (=JCM 14155T=DSM 18393T) in the genus Halobacillus as the respective type strains of the novel species Halobacillus profundi sp. nov. and Halobacillus kuroshimensis sp. nov.


Nematology ◽  
2021 ◽  
pp. 1-23
Author(s):  
Mei Na Liu ◽  
Yu Mei Xu ◽  
Zeng Qi Zhao ◽  
Jian Ming Wang

Summary This paper describes a new species of Bastiania, presents a new record and redescribes a known species of Tripyla. These nematodes are all in the order Triplonchida and were collected from Shanxi Province, North China. Bastiania sinensis sp. n. is characterised by having the female with a relatively slender body 1049-1295 μm long, dorsally arcuate after heat relaxation, with outer labial setae and cephalic setae in a single circle, an oval amphid, 7-8 laterodorsal cervical setae scattered in the pharyngeal region, orthometamenes and pseudocoelomocytes present, tail conoid with a mucron 1-2 μm long, two pairs of caudal setae present, a = 58.1-75.5, b = 4.0-4.6, c = 12.7-19.7, c′ = 4.1-7.8 and V = 61.1-67.7. Males were not found. Tripyla aquatica is recorded for the first time from China, and is redescribed. Tripyla setifera has been reported from China but without a detailed description – now provided. In addition, phylogenetic relationships among the species were analysed using data from the near full length small subunit (SSU) and D2-D3 segments of large subunit (LSU) of rRNA genes. Bastiania sinensis sp. n. is monophyletic with the Bastiania sequences available in GenBank, but is on an independent branch supporting its status as a separate species; T. aquatica and T. setifera are monophyletically clustered with known Tripyla species and grouped together with sequences from their respective species.


Author(s):  
Lina Sun ◽  
Wei Chen ◽  
Kaihua Huang ◽  
Weiguang Lyu ◽  
Xinhua Gao

Strain SJQ9T, an aerobic bacterium isolated from a soil sample collected in Shanghai, PR China, was characterized using a polyphasic approach. It grew optimally at pH 7.0, 30–35 °C and in the presence of 1 % (w/v) NaCl. A comparative analysis of 16S rRNA gene sequences showed that strain SJQ9T fell within the genus Aquabacterium . The closest phylogenetic relatives of strain SJQ9T were Aquabacterium citratiphilum DSM 11900T (98.6 % sequence similarity) and Aquabacterium commune DSM 11901T (96.4 %). Cells of the strain were Gram-stain-negative, motile, non-spore-forming, rod-shaped and positive for oxidase activity and negative for catalase. The chemotaxonomic properties of strain SJQ9T were consistent with those of the genus Aquabacterium : the major fatty acid was summed feature 3 (C16 : 1  ω6c and/or C16 : 1  ω7c). The isoprenoid quinone was Q-8. The major polar lipids were phosphatidylethanolamine, phosphatidylcholine, phosphatidylglycerol and diphosphatidylglycerol. The DNA G+C content was 65.7 mol%. Strain SH9T exhibited a DNA–DNA relatedness level of 34±2 % with A. citratiphilum DSM 11900T and 28±3 % with A. commune DSM 11901T. Based on the obtained data, strain SJQ9T represents a novel species of the genus Aquabacterium , for which the name Aquabacterium soli sp. nov. is proposed. The type strain is SJQ9T (=JCM 33106T=CCTCC AB 2018284T).


2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 5537-5537
Author(s):  
Tanya Kwan ◽  
Amit M. Oza ◽  
Domenica Lorusso ◽  
Carol Aghajanian ◽  
Ana Oaknin ◽  
...  

5537 Background: ARIEL3 is a placebo-controlled randomized trial of the PARP inhibitor (PARPi) rucaparib as maintenance treatment in HGOC patients (pts) who responded to the latest line of platinum therapy (NCT01968213). Rucaparib improved progression-free survival (PFS) across all predefined subgroups. Here, we present an exploratory analysis of clinical and molecular characteristics associated with exceptional benefit from rucaparib. Methods: Pts were randomized 2:1 to receive rucaparib 600 mg BID or placebo. At the data cutoff of Dec 31, 2019, 33/375 (9%) and 1/189 (0.5%) pts were still ongoing and receiving rucaparib or placebo, respectively. Molecular features (genomic alterations, BRCA1 promoter methylation) and baseline clinical characteristics were compared between pts who derived exceptional benefit (PFS ≥2 yrs), and those with disease progression on first scan (≈12 wks; the short-term [ST] subgroup) within each treatment arm. Results: Of 564 pts, 83 (15%) showed exceptional benefit: 79/375 (21%) in the rucaparib arm and 4/189 (2%) in the placebo arm. Within the rucaparib arm, exceptional benefit pts had more favorable clinical prognostic factors at baseline compared with the ST subgroup (Table). While BRCA mutations were enriched in the rucaparib exceptional benefit subgroup, 34/79 (43%) of these pts were BRCA wild type. Among other biomarkers, RAD51C/D mutations were associated with exceptional benefit; low genome-wide loss of heterozygosity was enriched within the ST subgroup; and high BRCA1 methylation was present at similar fractions. Trends were similar in the placebo arm (Table). Conclusions: Exceptional benefit in ARIEL3 was more common in, but not exclusive to, pts with favorable clinical characteristics and known mechanisms of PARPi sensitivity. Our results suggest that rucaparib can deliver exceptional benefit to a diverse set of HGOC pts. Clinical trial information: NCT01968213. [Table: see text]


Author(s):  
Qin Ma ◽  
Rui-Feng Lei ◽  
Yu-Qian Li ◽  
Dilireba Abudourousuli ◽  
Zulihumaer Rouzi ◽  
...  

A bacterial strain, designated YZGR15T, was isolated from the root of an annual halophyte Suaeda aralocaspica, collected from the southern edge of the Gurbantunggut desert, north-west PR China. Cells of the isolate were Gram-stain-positive, facultatively anaerobic, irregular rods. Growth occurred at 4–42 °C (optimum, 30–37 °C), at pH 6.0–9.0 (optimum, pH 7.0–7.5) and in the presence of 0–9 % (w/v) NaCl (optimum, 2–5 %). Phylogenetic analysis using 16S rRNA gene sequences indicated that strain YZGR15T showed the highest sequence similarity to Sanguibacter keddieii (98.27 %), Sanguibacter antarcticus (98.20 %) and Sanguibacter inulinus (98.06 %). Results of genome analyses of strain YZGR15T indicated that the genome size was 3.16 Mb, with a genomic DNA G+C content of 71.9 mol%. Average nucleotide identity and digital DNA–DNA hybridization values between strain YZGR15Tand three type strains were in the range of 76.5–77.8 % and 20.0–22.2 %, respectively. Analysis of the cellular component of strain YZGR15T revealed that the primary fatty acids were anteiso-C15 : 0, C16 : 0, C14 : 0 and iso-C16 : 0 and the polar lipids included diphosphatidylglycerol, phosphatidylglycerol, three unidentified phospholipids and two unidentified glycolipids. The cell-wall characteristic amino acids were glutamic acid, alanine and an unknown amino acid. The whole-cell sugars for the strain were mannose, ribose, rhamnose, glucose and an unidentified sugar. The predominant respiratory quinone was MK-9(H4). Based on the results of genomic, phylogenetic, phenotypic and chemotaxonomic analyses, strain YZGR15T represents a novel species of the genus Sanguibacter , for which the name Sanguibacter suaedae sp. nov. is proposed. The type strain is YZGR15T (=CGMCC 1.18691T=KCTC 49659T)


2004 ◽  
Vol 54 (4) ◽  
pp. 1349-1353 ◽  
Author(s):  
Chuji Hiruki ◽  
Keri Wang

Clover proliferation phytoplasma (CPR) is designated as the reference strain for the CP phylogenetic group or subclade, on the basis of molecular analyses of genomic DNA, the 16S rRNA gene and the 16S–23S spacer region. Other strains related to CPR include alfalfa witches'-broom (AWB), brinjal little leaf (BLL), beet leafhopper-transmitted virescence (BLTV), Illinois elm yellows (ILEY), potato witches'-broom (PWB), potato yellows (PY), tomato big bud in California (TBBc) and phytoplasmas from Fragaria multicipita (FM). Phylogenetic analysis of the 16S rRNA gene sequences of BLL, CPR, FM and ILEY, together with sequences from 16 other phytoplasmas that belong to the ash yellows (AshY), jujube witches'-broom (JWB) and elm yellows (EY) groups that were available in GenBank, produced a tree on which these phytoplasmas clearly clustered as a discrete group. Three subgroups have been classified on the basis of sequence homology and the collective RFLP patterns of amplified 16S rRNA genes. AWB, BLTV, PWB and TBBc are assigned to taxonomic subgroup CP-A, FM belongs to subgroup CP-B and BLL and ILEY are assigned to subgroup CP-C. Genetic heterogeneity between different isolates of AWB, CPR and PWB has been observed from heteroduplex mobility assay analysis of amplified 16S rRNA genes and the 16S–23S spacer region. Two unique signature sequences that can be utilized to distinguish the CP group from others were present. On the basis of unique properties of the DNA from clover proliferation phytoplasma, the name ‘Candidatus Phytoplasma trifolii’ is proposed for the CP group.


2007 ◽  
Vol 57 (12) ◽  
pp. 2908-2911 ◽  
Author(s):  
Hang-Yeon Weon ◽  
Seon-Young Lee ◽  
Byung-Yong Kim ◽  
Hyung-Jun Noh ◽  
Peter Schumann ◽  
...  

Two Gram-negative, rod-shaped, thermophilic bacterial strains, HC145T and HC148T, were isolated from a compost sample from a compost facility in Ichon, Korea. Sequencing of the 16S rRNA genes of HC145T and HC148T and comparative analyses of the resulting sequences clearly showed that these strains had a phylogenetic affiliation to the genus Ureibacillus. The level of 16S rRNA similarity between the two novel strains was 98.4 % and the levels of sequence similarity between them and existing Ureibacillus species were 97.8–98.1 (HC145T) and 97.4–98.7 % (HC148T). The DNA–DNA reassociation values between the two strains and the type strains of Ureibacillus species ranged from 38 to 51 %. The polar lipid profiles for both isolates consisted of phosphatidylglycerol, diphosphatidylglycerol, phospholipids and glycolipids of unknown composition. The major quinones were MK-8, MK-9 and MK-7, the peptidoglycan type was l-Lys←d-Asp and the main cellular fatty acid was iso-C16 : 0. The DNA G+C contents of strains HC145T and HC148T were 42.4 and 38.5 mol%, respectively. On the basis of the data from this polyphasic study, strains HC145T and HC148T represent members of the genus Ureibacillus, for which the names Ureibacillus composti sp. nov. and Ureibacillus thermophilus sp. nov., respectively, are proposed. The type strain of U. composti is HC145T (=KACC 11361T =DSM 17951T) and the type strain of U. thermophilus is HC148T (=KACC 11362T =DSM 17952T).


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