scholarly journals Characterization of Cyanate Metabolism in MarineSynechococcusandProchlorococcusspp.

2010 ◽  
Vol 77 (1) ◽  
pp. 291-301 ◽  
Author(s):  
Nina A. Kamennaya ◽  
Anton F. Post
Keyword(s):  
Nitrogen Metabolism ◽  
Stress Responses ◽  
Global Ocean ◽  
Marine Cyanobacteria ◽  
Genomic Context ◽  
Carbamoyl Phosphate ◽  
Marine Food Webs ◽  
Photosynthetic Organisms ◽  
Marine Food

ABSTRACTCyanobacteria of the generaSynechococcusandProchlorococcusare the most abundant photosynthetic organisms on earth, occupying a key position at the base of marine food webs. ThecynSgene that encodes cyanase was identified among bacterial, fungal, and plant sequences in public databases, and the gene was particularly prevalent among cyanobacteria, including numerousProchlorococcusandSynechococcusstrains. Phylogenetic analysis ofcynSsequences retrieved from the Global Ocean Survey database identified >60% as belonging to unicellular marine cyanobacteria, suggesting an important role for cyanase in their nitrogen metabolism. We demonstrate here that marine cyanobacteria have a functionally active cyanase, the transcriptional regulation of which varies among strains and reflects the genomic context ofcynS. InProchlorococcussp. strain MED4,cynSwas presumably transcribed as part of thecynABDSoperon, implying cyanase involvement in cyanate utilization. InSynechococcussp. strain WH8102, expression was not related to nitrogen stress responses and here cyanase presumably serves in the detoxification of cyanate resulting from intracellular urea and/or carbamoyl phosphate decomposition. Lastly, we report on a cyanase activity encoded bycynH, a novel gene found in marine cyanobacteria only. The presence of dual cyanase genes in the genomes of seven marineSynechococcusstrains and their respective roles in nitrogen metabolism remain to be clarified.

Ultrastructural identification of three types of sensory setae on copepod antennae

1995 ◽  
Vol 53 ◽  
pp. 956-957
Author(s):  
T. M. Weatherby ◽  
P.H. Lenz
Keyword(s):  
Phase Locking ◽  
Membrane Surface ◽  
Reaction Times ◽  
High Sensitivity ◽  
Structural Features ◽  
Calanoid Copepods ◽  
Marine Food Webs ◽  
Dendritic Membrane ◽  
Ultrastructural Characterization

Crustaceans, as well as other arthropods, are covered with sensory setae and hairs, including mechanoand chemosensory sensillae with a ciliary origin. Calanoid copepods are small planktonic crustaceans forming a major link in marine food webs. In conjunction with behavioral and physiological studies of the antennae of calanoids, we undertook the ultrastructural characterization of sensory setae on the antennae of Pleuromamma xiphias.Distal mechanoreceptive setae exhibit exceptional behavioral and physiological performance characteristics: high sensitivity (<10 nm displacements), fast reaction times (<1 msec latency) and phase locking to high frequencies (1-2 kHz). Unusual structural features of the mechanoreceptors are likely to be related to their physiological sensitivity. These features include a large number (up to 3000) of microtubules in each sensory cell dendrite, arising from or anchored to electron dense rods associated with the ciliary basal body microtubule doublets. The microtubules are arranged in a regular array, with bridges between and within rows. These bundles of microtubules extend far into each mechanoreceptive seta and terminate in a staggered fashion along the dendritic membrane, contacting a large membrane surface area and providing a large potential site of mechanotransduction.

Proteome characterization of copper stress responses in the roots of sorghum

BioMetals ◽  
2017 ◽  
Vol 30 (5) ◽  
pp. 765-785 ◽  
Author(s):  
Swapan Kumar Roy ◽  
Seong-Woo Cho ◽  
Soo Jeong Kwon ◽  
Abu Hena Mostafa Kamal ◽  
Dong-Gi Lee ◽  
...  
Keyword(s):  
Stress Responses ◽  
Copper Stress

Systematic discovery and characterization of stress-related microRNA genes in Oryza sativa

Biologia ◽  
2015 ◽  
Vol 70 (1) ◽  
Author(s):  
Kai Bin Xie ◽  
Xue Zhou ◽  
Tian Hai Zhang ◽  
Bao Long Zhang ◽  
Li Ming Chen ◽  
...  
Keyword(s):  
Abiotic Stress ◽  
Stress Responses ◽  
Systematic Investigation ◽  
Chemical Toxicity ◽  
Promoter Regions ◽  
Crop Species ◽  
Translation Inhibition ◽  
Microrna Genes ◽  
Insight Into

AbstractAbiotic stresses including drought, salinity, extreme temperatures, chemical toxicity and oxidative are the natural status of the environment to exert serious threats to agriculture. Abiotic stress-related microRNAs (ASmiRNAs) are a group of microRNAs (miRNAs) regulating stress responses in plants. However, the systematic investigation of ASmiRNAs is limited in Rice (O. sativa), a typical abiotic stress-resistant crop species. In the present work, we systematically investigated ASmiRNAs in silico. First, we identified 177 putative ASmiRNAs in O.sativa. Second, we found most ASmiRNAs were driven by TATA-promoter and most stress-related miRNA promoter regions contained the stress-related elements. Third, we found many ASmiRNAs families were species/family specific and a set of miRNAs might derive from genomic repeat-sequences in O. sativa. Finally, we found the ASmiRNAs in O. sativa target 289 genes with 1050 predicted target sites in which 98% sites have cleavage activity and 2% sites have translation inhibition activity. In conclusion, our findings provide an insight into both the function and evolution of ASmiRNAs and improve our understanding on the mechanism of abiotic stress resistance in O. sativa.

Characterization of potato (Solanum tuberosum) and tomato (Solanum lycopersicum) protein phosphatases type 2A catalytic subunits and their involvement in stress responses

Planta ◽  
2009 ◽  
Vol 230 (1) ◽  
pp. 13-25 ◽  
Author(s):  
Silvia Marina País ◽  
Marina Alejandra González ◽  
María Teresa Téllez-Iñón ◽  
Daniela Andrea Capiati
Keyword(s):  
Solanum Tuberosum ◽  
Solanum Lycopersicum ◽  
Stress Responses ◽  
Protein Phosphatases ◽  
Catalytic Subunits

scholarly journals Identification and Characterization of Genes Required for 5-Hydroxyuridine Synthesis in Bacillus subtilis and Escherichia coli tRNA

2019 ◽  
Vol 201 (20) ◽  
Author(s):  
Charles T. Lauhon
Keyword(s):  
Escherichia Coli ◽  
Bacillus Subtilis ◽  
Genomic Context ◽  
Similar Reduction ◽  
Content Type ◽  
E Coli ◽  
Wobble Position ◽  
Fertile Ground ◽  
And Function

ABSTRACT In bacteria, tRNAs that decode 4-fold degenerate family codons and have uridine at position 34 of the anticodon are typically modified with either 5-methoxyuridine (mo5U) or 5-methoxycarbonylmethoxyuridine (mcmo5U). These modifications are critical for extended recognition of some codons at the wobble position. Whereas the alkylation steps of these modifications have been described, genes required for the hydroxylation of U34 to give 5-hydroxyuridine (ho5U) remain unknown. Here, a number of genes in Escherichia coli and Bacillus subtilis are identified that are required for wild-type (wt) levels of ho5U. The yrrMNO operon is identified in B. subtilis as important for the biosynthesis of ho5U. Both yrrN and yrrO are homologs to peptidase U32 family genes, which includes the rlhA gene required for ho5C synthesis in E. coli. Deletion of either yrrN or yrrO, or both, gives a 50% reduction in mo5U tRNA levels. In E. coli, yegQ was found to be the only one of four peptidase U32 genes involved in ho5U synthesis. Interestingly, this mutant shows the same 50% reduction in (m)cmo5U as that observed for mo5U in the B. subtilis mutants. By analyzing the genomic context of yegQ homologs, the ferredoxin YfhL is shown to be required for ho5U synthesis in E. coli to the same extent as yegQ. Additional genes required for Fe-S biosynthesis and biosynthesis of prephenate give the same 50% reduction in modification. Together, these data suggest that ho5U biosynthesis in bacteria is similar to that of ho5C, but additional genes and substrates are required for complete modification. IMPORTANCE Modified nucleotides in tRNA serve to optimize both its structure and function for accurate translation of the genetic code. The biosynthesis of these modifications has been fertile ground for uncovering unique biochemistry and metabolism in cells. In this work, genes that are required for a novel anaerobic hydroxylation of uridine at the wobble position of some tRNAs are identified in both Bacillus subtilis and Escherichia coli. These genes code for Fe-S cluster proteins, and their deletion reduces the levels of the hydroxyuridine by 50% in both organisms. Additional genes required for Fe-S cluster and prephenate biosynthesis and a previously described ferredoxin gene all display a similar reduction in hydroxyuridine levels, suggesting that still other genes are required for the modification.

Stable nitrogen and carbon isotopes in sediments and biota from three tropical marine food webs: Application to chemical bioaccumulation assessment

2017 ◽  
Vol 36 (9) ◽  
pp. 2521-2532 ◽  
Author(s):  
Hui Zhang ◽  
Yun Teng ◽  
Tra Thi Thanh Doan ◽  
Yun Wei Yat ◽  
Sheot Harn Chan ◽  
...  
Keyword(s):  
Food Webs ◽  
Carbon Isotopes ◽  
Marine Food Webs ◽  
Marine Food

scholarly journals Krill: a potential vector for domoic acid in marine food webs

2002 ◽  
Vol 237 ◽  
pp. 209-216 ◽  
Author(s):  
S Bargu ◽  
CL Powell ◽  
SL Coale ◽  
M Busman ◽  
GJ Doucette ◽  
...  
Keyword(s):  
Food Webs ◽  
Domoic Acid ◽  
Potential Vector ◽  
Marine Food Webs ◽  
Marine Food

scholarly journals Genome-Wide Identification and Characterization of the RCI2 Gene Family in Allotetraploid Brassica napus Compared with Its Diploid Progenitors

2022 ◽  
Vol 23 (2) ◽  
pp. 614
Author(s):  
Weiqi Sun ◽  
Mengdi Li ◽  
Jianbo Wang
Keyword(s):  
Brassica Napus ◽  
Gene Family ◽  
Gene Structure ◽  
Stress Responses ◽  
Stress Protein ◽  
Purifying Selection ◽  
Cis Acting ◽  
Genome Wide ◽  
Duplication Events

Brassica napus and its diploid progenitors (B. rapa and B. oleracea) are suitable for studying the problems associated with polyploidization. As an important anti-stress protein, RCI2 proteins widely exist in various tissues of plants, and are crucial to plant growth, development, and stress response. In this study, the RCI2 gene family was comprehensively identified and analyzed, and 9, 9, and 24 RCI2 genes were identified in B. rapa, B. oleracea, and B. napus, respectively. Phylogenetic analysis showed that all of the identified RCI2 genes were divided into two groups, and further divided into three subgroups. Ka/Ks analysis showed that most of the identified RCI2 genes underwent a purifying selection after the duplication events. Moreover, gene structure analysis showed that the structure of RCI2 genes is largely conserved during polyploidization. The promoters of the RCI2 genes in B. napus contained more cis-acting elements, which were mainly involved in plant development and growth, plant hormone response, and stress responses. Thus, B. napus might have potential advantages in some biological aspects. In addition, the changes of RCI2 genes during polyploidization were also discussed from the aspects of gene number, gene structure, gene relative location, and gene expression, which can provide reference for future polyploidization analysis.

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