scholarly journals Comparative Time-Course Physiological Responses and Proteomic Analysis of Melatonin Priming on Promoting Germination in Aged Oat (Avena sativa L.) Seeds

2021 ◽  
Vol 22 (2) ◽  
pp. 811
Author(s):  
Huifang Yan ◽  
Peisheng Mao
Keyword(s):  
Antioxidant Capacity ◽  
Avena Sativa ◽  
Proteomic Analysis ◽  
Time Course ◽  
Intact Cell ◽  
Membrane Integrity ◽  
Acid Synthesis ◽  
Ultrastructural Changes ◽  
Oat Seeds ◽  
Aged Seeds

Melatonin priming is an effective strategy to improve the germination of aged oat (Avena sativa L.) seeds, but the mechanism involved in its time-course responses has remained largely unknown. In the present study, the phenotypic differences, ultrastructural changes, physiological characteristics, and proteomic profiles were examined in aged and melatonin-primed seed (with 10 μM melatonin treatment for 12, 24, and 36 h). Thus, 36 h priming (T36) had a better remediation effect on aged seeds, reflecting in the improved germinability and seedlings, relatively intact cell ultrastructures, and enhanced antioxidant capacity. Proteomic analysis revealed 201 differentially abundant proteins between aged and T36 seeds, of which 96 were up-accumulated. In melatonin-primed seeds, the restoration of membrane integrity by improved antioxidant capacity, which was affected by the stimulation of jasmonic acid synthesis via up-accumulation of 12-oxo-phytodienoic acid reductase, might be a candidate mechanism. Moreover, the relatively intact ultrastructures enabled amino acid metabolism and phenylpropanoid biosynthesis, which were closely associated with energy generation through intermediates of pyruvate, phosphoenolpyruvate, fumarate, and α-ketoglutarate, thus providing energy, active amino acids, and secondary metabolites necessary for germination improvement of aged seeds. These findings clarify the time-course related pathways associated with melatonin priming on promoting the germination of aged oat seeds.

scholarly journals Melatonin Priming Alleviates Aging-Induced Germination Inhibition by Regulating β-oxidation, Protein Translation, and Antioxidant Metabolism in Oat (Avena sativa L.) Seeds

2020 ◽  
Vol 21 (5) ◽  
pp. 1898 ◽  
Author(s):  
Huifang Yan ◽  
Shangang Jia ◽  
Peisheng Mao
Keyword(s):  
Tca Cycle ◽  
Protein Translation ◽  
Cell Ultrastructure ◽  
Ultrastructural Changes ◽  
Protein Profiles ◽  
Antioxidant Metabolism ◽  
Antioxidant Responses ◽  
Oat Seeds ◽  
Underlying Mechanisms ◽  
Aged Seeds

Although melatonin has been reported to play an important role in regulating metabolic events under adverse stresses, its underlying mechanisms on germination in aged seeds remain unclear. This study was conducted to investigate the effect of melatonin priming (MP) on embryos of aged oat seeds in relation to germination, ultrastructural changes, antioxidant responses, and protein profiles. Proteomic analysis revealed, in total, 402 differentially expressed proteins (DEPs) in normal, aged, and aged + MP embryos. The downregulated DEPs in aged embryos were enriched in sucrose metabolism, glycolysis, β-oxidation of lipid, and protein synthesis. MP (200 μM) turned four downregulated DEPs into upregulated DEPs, among which, especially 3-ketoacyl-CoA thiolase-like protein (KATLP) involved in the β-oxidation pathway played a key role in maintaining TCA cycle stability and providing more energy for protein translation. Furthermore, it was found that MP enhanced antioxidant capacity in the ascorbate-glutathione (AsA-GSH) system, declined reactive oxygen species (ROS), and improved cell ultrastructure. These results indicated that the impaired germination and seedling growth of aged seeds could be rescued to a certain level by melatonin, predominantly depending on β-oxidation, protein translation, and antioxidant protection of AsA-GSH. This work reveals new insights into melatonin-mediated mechanisms from protein profiles that occur in embryos of oat seeds processed by both aging and priming.

Ultrastructural Changes of the Symbiotic Chlorella-Like Alga Isolated from Hydra Viridis

1982 ◽  
Vol 40 ◽  
pp. 320-321
Author(s):  
K.W. Lee ◽  
R.H. Meints ◽  
D. Kuczmarski ◽  
J.L. Van Etten
Keyword(s):  
Time Course ◽  
Reciprocal Cross ◽  
Ultrastructural Level ◽  
Ultrastructural Changes ◽  
Symbiotic Relationship ◽  
Cell Recognition ◽  
Green Hydra ◽  
Different Strains ◽  
Hydra Viridis

The physiological, biochemical, and ultrastructural aspects of the symbiotic relationship between the Chlorella-like algae and the hydra have been intensively investigated. Reciprocal cross-transfer of the Chlorellalike algae between different strains of green hydra provide a system for the study of cell recognition. However, our attempts to culture the algae free of the host hydra of the Florida strain, Hydra viridis, have been consistently unsuccessful. We were, therefore, prompted to examine the isolated algae at the ultrastructural level on a time course.

In situ studies on alginic acid synthesis and other aspects of the metabolism of Laminaria digitata

1972 ◽  
Vol 50 (1) ◽  
pp. 177-184 ◽  
Author(s):  
Johan A. Hellebust ◽  
Arne Haug
Keyword(s):  
Amino Acids ◽  
Time Course ◽  
Alginic Acid ◽  
Acid Synthesis ◽  
Short Term ◽  
Fresh Weight Basis ◽  
Mannuronic Acid ◽  
Guluronic Acid ◽  
Rate Of Photosynthesis

Amino acids, particularly alanine and aspartate, become more strongly labeled than mannitol in short-term 14C-photoassimilation experiments. The amino acids are the most likely sources of carbon for alginic acid synthesis and respiration in the dark, in contrast to mannitol, which appears to be relatively unavailable. Temperature is very important in determining the rate of loss of recent photoassimilate in L. digitata. The rate of photosynthesis, on a fresh weight basis, is much higher for blades than for stipes.The time course for incorporation of photoassimilated carbon into alginate differs for the stipe and blade both in light and dark periods. Very little 14C enters alginate in blades in the dark, while alginate in stipes acquires considerable amounts of activity during dark periods. Alginate in both blade and stipe acquires 14C predominantly in mannuronic acid residues of their alginate during short-term photoassimilation periods, while guluronic acid residues become relatively more rapidly labeled during dark periods.

Photosynthesis, translocation, and alginic acid synthesis in Laminaria digitata and Laminaria hyperborea

1972 ◽  
Vol 50 (1) ◽  
pp. 169-176 ◽  
Author(s):  
Johan A. Hellebust ◽  
Arne Haug
Keyword(s):  
Time Course ◽  
Alginic Acid ◽  
Acid Synthesis ◽  
Laminaria Hyperborea ◽  
Short Term ◽  
Fresh Weight Basis ◽  
Mannuronic Acid ◽  
Guluronic Acid ◽  
Isolated Cortex ◽  
Photosynthetic Capacities

New and old tissues of L. digitata blades have very similar photosynthetic capacities on a fresh weight basis. Very little of the photoassimilate goes into alginic acid, or other macromolecular substances in old blade tissues. Less than 1% of the photoassimilated 14C in the old blade portion of a L. digitata blade was translocated to the new blade tissues in a 5-h experiment. In contrast, there is rapid transport of photoassimilate from bark cells to cells of the underlying tissues of L. digitata and L. hyperborea stipe sections. Isolated cortex and medulla tissues of L. digitata stipes have significant photosynthetic capacities, but are probably so strongly shaded by the darkly pigmented bark cells that little photosynthesis can normally occur in these tissues.A larger proportion of the photoassimilated carbon enters alginate in the cortex and medulla than in the bark of L. digitata and L. hyperborea stipes in short-term experiments. The time course for incorporation of photosynthate into alginate in continuous and pulse-labeling experiments indicates the presence of relatively large pools of alginate precursors. A large proportion of the total 14C incorporated into alginate in short-term experiments is found in the "M–M" (mannuronic acid) and "M–G" (alternating mannuronic and guluronic acid) block components.

scholarly journals Ornithine decarboxylase activity and the onset of deoxyribonucleic acid synthesis in regenerating liver

1978 ◽  
Vol 170 (1) ◽  
pp. 123-127 ◽  
Author(s):  
J A McGowan ◽  
N Fausto
Keyword(s):  
Dna Synthesis ◽  
Ornithine Decarboxylase ◽  
Time Course ◽  
Deoxyribonucleic Acid ◽  
Acid Synthesis ◽  
Decarboxylase Activity ◽  
Ornithine Decarboxylase Activity ◽  
Low Protein ◽  
Deoxyribonucleic Acid Synthesis ◽  
Second Peak

Compared with normally fed animals, rats fed on a low-protein diet for 3 days exhibit a considerable delay in DNA synthesis after partial hepatectomy. In the regenerating livers of these animals (a) the timing of the first peak of ornithine decarboxylase activity is not altered and (b) the second peak of enzyme activity is delayed by a few hours, but polyamine concentrations are similar to those of normally fed rats. The results suggest that regardless of the possible effect of polyamines on DNA synthesis, the time course of ornithine decarboxylase activity appears to be independent of the onset of DNA replication in regenerating livers.

Nonpolar movement of N6-benzyladenine-14C in coleoptile, stem, petiole, and floral organ sections

1973 ◽  
Vol 51 (11) ◽  
pp. 2079-2083 ◽  
Author(s):  
James L. Koevenig
Keyword(s):  
Avena Sativa ◽  
Time Course ◽  
Floral Organ ◽  
Scintillation Counting ◽  
Passive Diffusion ◽  
Plant Organs ◽  
Polar Movement ◽  
Metabolic Difference

Movement of N6-benzyladenine-methylene-14C in Avena sativa coleoptiles, Colens blumei stems and petioles, and Cleome hassleriana stamen filaments, gynophores, and pedicels was studied by suspending sections horizontally between donor and receiver agar cylinders and determining radioactivity in receivers by scintillation counting. No polar movement was found in any of the plant organs. In time-course experiments using oat coleoptiles, the amount of radioactivity in receivers continued to increase for 24 h and the velocity was 1.5-2 mm/h, suggesting movement by passive diffusion. More radioactivity moved through stamen filaments and gynophore sections from mature expanded flowers than through those from young buds, apparently as a result of larger uptake and exit areas in expanded flowers. A significantly greater acropetal and basipetal movement through young pedicels is not due to area differences and probably results from a metabolic difference.

A drug candidate for Alzheimer’s and Huntington’s disease, PBT2, can be repurposed to render Neisseria gonorrhoeae susceptible to natural cationic antimicrobial peptides

2021 ◽  
Author(s):  
Freda E -C Jen ◽  
Ibrahim M El-Deeb ◽  
Yaramah M Zalucki ◽  
Jennifer L Edwards ◽  
Mark J Walker ◽  
...  
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Antimicrobial Peptides ◽  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Proteomic Analysis ◽  
Protein Misfolding ◽  
Membrane Integrity ◽  
Drug Candidate ◽  
Cationic Antimicrobial Peptides ◽  
Broth Microdilution Method

Abstract Background Neisseria gonorrhoeae is a Gram-negative bacterial pathogen that causes gonorrhoea. No vaccine is available to prevent gonorrhoea and the emergence of MDR N. gonorrhoeae strains represents an immediate public health threat. Objectives To evaluate whether PBT2/zinc may sensitize MDR N. gonorrhoeae to natural cationic antimicrobial peptides. Methods MDR strains that contain differing resistance mechanisms against numerous antibiotics were tested in MIC assays. MIC assays were performed using the broth microdilution method according to CLSI guidelines in a microtitre plate. Serially diluted LL-37 or PG-1 was tested in combination with a sub-inhibitory concentration of PBT2/zinc. Serially diluted tetracycline was also tested with sub-inhibitory concentrations of PBT2/zinc and LL-37. SWATH-MS proteomic analysis of N. gonorrhoeae treated with PBT2/zinc, LL-37 and/or tetracycline was performed to determine the mechanism(s) of N. gonorrhoeae susceptibility to antibiotics and peptides. Results Sub-inhibitory concentrations of LL-37 and PBT2/zinc synergized to render strain WHO-Z susceptible to tetracycline, whereas the killing effect of PG-1 and PBT2/zinc was additive. SWATH-MS proteomic analysis suggested that PBT2/zinc most likely leads to a loss of membrane integrity and increased protein misfolding and, in turn, results in bacterial death. Conclusions Here we show that PBT2, a candidate Alzheimer’s and Huntington’s disease drug, can be repurposed to render MDR N. gonorrhoeae more susceptible to the endogenous antimicrobial peptides LL-37 and PG-1. In the presence of LL-37, PBT2/zinc can synergize with tetracycline to restore tetracycline susceptibility to gonococci resistant to this antibiotic.

Effect of extrusion pretreatment on extraction, quality and antioxidant capacity of oat (Avena Sativa L.) bran oil

2020 ◽  
Vol 95 ◽  
pp. 102972
Author(s):  
Jing Liu ◽  
Shengye Jin ◽  
Hongdong Song ◽  
Kai Huang ◽  
Sen Li ◽  
...  
Keyword(s):  
Antioxidant Capacity ◽  
Avena Sativa

scholarly journals Particle Assembly and Ultrastructural Features Associated with Replication of the Lytic Archaeal Virus Sulfolobus Turreted Icosahedral Virus

2009 ◽  
Vol 83 (12) ◽  
pp. 5964-5970 ◽  
Author(s):  
Susan K. Brumfield ◽  
Alice C. Ortmann ◽  
Vincent Ruigrok ◽  
Peter Suci ◽  
Trevor Douglas ◽  
...  
Keyword(s):  
Time Course ◽  
Plaque Assay ◽  
Ultrastructural Changes ◽  
Progeny Virus ◽  
Particle Assembly ◽  
Virus Particles ◽  
Transmission Electron ◽  
Archaeal Viruses ◽  
Infected Cells ◽  
Sulfolobus Turreted Icosahedral Virus

ABSTRACT Little is known about the replication cycle of archaeal viruses. We have investigated the ultrastructural changes of Sulfolobus solfataricus P2 associated with infection by Sulfolobus turreted icosahedral virus (STIV). A time course of a near synchronous STIV infection was analyzed using both scanning and transmission electron microscopy. Assembly of STIV particles, including particles lacking DNA, was observed within cells, and fully assembled STIV particles were visible by 30 h postinfection (hpi). STIV was determined to be a lytic virus, causing cell disruption beginning at 30 hpi. Prior to cell lysis, virus infection resulted in the formation of pyramid-like projections from the cell surface. These projections, which have not been documented in any other host-virus system, appeared to be caused by the protrusion of the cell membrane beyond the bordering S-layer. These structures are thought to be sites at which progeny virus particles are released from infected cells. Based on these observations of lysis, a plaque assay was developed for STIV. From these studies we propose an overall assembly model for STIV.

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