Germination associated ROS production and glutathione redox capacity in two recalcitrant-seeded species differing in seed longevity

Botany ◽  
2016 ◽  
Vol 94 (12) ◽  
pp. 1103-1114 ◽  
Author(s):  
Anushka Moothoo-Padayachie ◽  
Boby Varghese ◽  
Norman W. Pammenter ◽  
Patrick Govender ◽  
Sershen
Keyword(s):  
Water Uptake ◽  
Germination Rate ◽  
High Water ◽  
Avicennia Marina ◽  
Ros Production ◽  
Recalcitrant Seeds ◽  
Ros Scavenging ◽  
Redox Capacity ◽  
Uptake Rates ◽  
Positive Correlations

This study investigated the relationship between germination rate and storage lifespan in two recalcitrant-seeded species, Avicennia marina (Forssk.) Vierh. and Trichilia dregeana Sond., in relation to water uptake and oxidative metabolism. Seeds of A. marina had a higher germination rate and shorter hydrated storage lifespan than T. dregeana. Rapid germination of A. marina seeds was associated with high water uptake rates and an early increase in reactive oxygen species (ROS) production and decline in GSH:GSSG ratio. Slower germination in T. dregeana seeds was associated with lower water uptake rates, delayed onset of the ROS-based trigger for germination, and high GSH:GSSG ratio. Positive correlations (p < 0.05) between ROS production and percent water uptake, and inhibition of germination by ROS scavenging agents confirmed the requirement for heightened ROS levels for germination in both species. Germination rate in recalcitrant seeds appears to be governed by the rate of water uptake and ROS production; the latter being dependent on antioxidant activity. We propose that poor longevity in recalcitrant seeds, such as those of A. marina, is based on high rates of water uptake and low levels of ROS scavenging activity that promote the ROS-based trigger for germination during hydrated storage.

scholarly journals The Effect of Drying of Bread Wheat Seeds Following First Water Uptake on Germination Rate

2018 ◽  
Vol 6 (1) ◽  
pp. 28
Author(s):  
Mustafa Yıldırım
Keyword(s):  
Bread Wheat ◽  
Water Uptake ◽  
Germination Rate ◽  
Seed Viability ◽  
Weather Conditions ◽  
Significant Negative Correlation ◽  
Limiting Factors ◽  
Germination Ability ◽  
Uptake Rates ◽  
Germinating Seeds

In semi-arid regions, unfavorable weather conditions are the most important limiting factors for seed germination. The imbibed or germinating seeds in soil can be dried by hot and dry weather. Thus, seeds can largely lose their germination abilities until the next water uptake (called as ‘alatav’ in Turkish). Before drying, the time of the first water uptake by a seed may be more effective on seed viability at the second water uptake for germination. Therefore, this experiment was conducted to identify the first water uptake rates (WU) of seeds of three bread wheat genotypes (Bezotaja, Kirac and 13-BVD-4) per hour during 50 hours and their germination rates (GR) at the second water uptake after drying the seeds for 3-week in laboratory conditions. The results presented here indicated that the WU and GR were significantly affected by genotypes, imbibition time (T) and their interaction (1% probability level). There was also a significant negative correlation between the WU and GR (r** = –0.9295) at all times studied. Furthermore, the germination ability of Kirac lasted longest (for 38th hour) when the WU reached to 160.24%, and it was followed by Bezostaya and 13-BVD-4 genotypes (63.34% at 37th hour and 152.58% 34th hour, respectively).

scholarly journals The effect of lizards on the dispersal and germination of Capparis spinosa (Capparaceae)

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0247585
Author(s):  
Yi Yang ◽  
Yingying Lin ◽  
Lei Shi
Keyword(s):  
Seed Germination ◽  
Seed Dispersal ◽  
Water Uptake ◽  
Germination Rate ◽  
Defecation Rate ◽  
Uptake Rates ◽  
Capparis Spinosa ◽  
The Mean ◽  
Viable Seeds ◽  
Seed Coats

Seed dispersal is a key component of the interactions between plants and animals. There is little research on the effects of lizard seed dispersal, which is more common on islands than elsewhere. In this study, the effects of the passage of Capparis spinosa seeds through Teratoscincus roborowskii lizard digestive tracts on the seed coats, water uptake rates and germination rates were investigated. In addition, the spatial patterns of fecal deposition by lizards in various microhabitats were assessed. Our results showed that the mean retention time (MRT) of mealworms was significantly longer than that of C. spinosa seeds in both adult and juvenile lizards. The defecation rate of C. spinosa tended to be lower than that of mealworms, which might be beneficial for seed dispersal. It was determined that the longer MRT of C. spinosa seeds enhanced the permeability of the seed coats, which promoted fast water uptake, broke seed dormancy and increased the seed germination rate. Furthermore, the seeds that passed through the digestive tracts of lizards were deposited in favorable germination microhabitats. By enhancing seed germination and depositing intact and viable seeds in safe potential recruitment sites, the lizard T. roborowskii acts, at least qualitatively, as an effective disperser of C. spinosa.

scholarly journals Production and scavenging of reactive oxygen species both affect reproductive success in male and female Drosophila melanogaster

2021 ◽  
Author(s):  
Biz R. Turnell ◽  
Luisa Kumpitsch ◽  
Klaus Reinhardt
Keyword(s):  
Reactive Oxygen Species ◽  
Drosophila Melanogaster ◽  
Reactive Oxygen ◽  
Cellular Aging ◽  
Ros Production ◽  
Oxygen Species ◽  
Wild Type ◽  
Ros Scavenging ◽  
Respiratory Pathway ◽  
Male And Female

AbstractSperm aging is accelerated by the buildup of reactive oxygen species (ROS), which cause oxidative damage to various cellular components. Aging can be slowed by limiting the production of mitochondrial ROS and by increasing the production of antioxidants, both of which can be generated in the sperm cell itself or in the surrounding somatic tissues of the male and female reproductive tracts. However, few studies have compared the separate contributions of ROS production and ROS scavenging to sperm aging, or to cellular aging in general. We measured reproductive fitness in two lines of Drosophila melanogaster genetically engineered to (1) produce fewer ROS via expression of alternative oxidase (AOX), an alternative respiratory pathway; or (2) scavenge fewer ROS due to a loss-of-function mutation in the antioxidant gene dj-1β. Wild-type females mated to AOX males had increased fecundity and longer fertility durations, consistent with slower aging in AOX sperm. Contrary to expectations, fitness was not reduced in wild-type females mated to dj-1β males. Fecundity and fertility duration were increased in AOX and decreased in dj-1β females, indicating that female ROS levels may affect aging rates in stored sperm and/or eggs. Finally, we found evidence that accelerated aging in dj-1β sperm may have selected for more frequent mating. Our results help to clarify the relative roles of ROS production and ROS scavenging in the male and female reproductive systems.

Hydraulic segmentation does not protect stems from acute water loss during fire

2021 ◽  
Author(s):  
William A Hoffmann ◽  
Amanda C Rodrigues ◽  
Nicholas Uncles ◽  
Lorenzo Rossi
Keyword(s):  
Water Uptake ◽  
Water Loss ◽  
High Water ◽  
Fire Plume ◽  
Magnolia Grandiflora ◽  
Hydraulic Failure ◽  
Factors Influencing ◽  
Wide Range ◽  
Transport Path ◽  
Measured Water

Abstract The heat plume associated with fire has been hypothesized to cause sufficient water loss from trees to induce embolism and hydraulic failure. However, it is unclear whether the water transport path remains sufficiently intact during scorching or burning of foliage to sustain high water loss. We measured water uptake by branches of Magnolia grandiflora while exposing them to a range of fire intensities, and examined factors influencing continued water uptake after fire. Burning caused a 22-fold mean increase in water uptake, with greatest rates of water loss observed at burn intensities that caused complete consumption of leaves. Such rapid uptake is possible only with steep gradients in water potential, which would likely result in substantial cavitation of xylem and loss of conductivity in intact stems. Water uptake continued after burning was complete, and was greatest following burn intensities that killed leaves but did not consume them. This post-fire uptake was mostly driven by rehydration of the remaining tissues, rather than evaporation from the tissues. Our results indicate that the fire-plume hypothesis can be expanded to include a wide range of burning conditions experienced by plants. High rates of water loss are sustained during burning, even when leaves are killed or completely consumed.

scholarly journals Somatic production of reactive oxygen species does not predict its production in sperm cells across Drosophila melanogaster lines

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Biz R. Turnell ◽  
Luisa Kumpitsch ◽  
Anne-Cécile Ribou ◽  
Klaus Reinhardt
Keyword(s):  
Reactive Oxygen Species ◽  
Drosophila Melanogaster ◽  
Reactive Oxygen ◽  
Future Research ◽  
Ros Production ◽  
Oxygen Species ◽  
Loss Of Function ◽  
Wild Type ◽  
Ros Scavenging ◽  
Transport Chain

Abstract Objective Sperm ageing has major evolutionary implications but has received comparatively little attention. Ageing in sperm and other cells is driven largely by oxidative damage from reactive oxygen species (ROS) generated by the mitochondria. Rates of organismal ageing differ across species and are theorized to be linked to somatic ROS levels. However, it is unknown whether sperm ageing rates are correlated with organismal ageing rates. Here, we investigate this question by comparing sperm ROS production in four lines of Drosophila melanogaster that have previously been shown to differ in somatic mitochondrial ROS production, including two commonly used wild-type lines and two lines with genetic modifications standardly used in ageing research. Results Somatic ROS production was previously shown to be lower in wild-type Oregon-R than in wild-type Dahomey flies; decreased by the expression of alternative oxidase (AOX), a protein that shortens the electron transport chain; and increased by a loss-of-function mutation in dj-1β, a gene involved in ROS scavenging. Contrary to predictions, we found no differences among these four lines in the rate of sperm ROS production. We discuss the implications of our results, the limitations of our study, and possible directions for future research.

scholarly journals Will the Bacteria Survive in the CeO2 Nanozyme-H2O2 System?

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3747
Author(s):  
Weisheng Zhu ◽  
Luyao Wang ◽  
Qisi Li ◽  
Lizhi Jiao ◽  
Xiaokan Yu ◽  
...  
Keyword(s):  
Peroxidase Activity ◽  
Biomedical Applications ◽  
Antibacterial Effect ◽  
Ros Production ◽  
Ros Scavenging ◽  
Ros Scavenger ◽  
Oxide Nanoparticle ◽  
H2o2 System ◽  
Bacterial Disinfection

As one of the nanostructures with enzyme-like activity, nanozymes have recently attracted extensive attention for their biomedical applications, especially for bacterial disinfection treatment. Nanozymes with high peroxidase activity are considered to be excellent candidates for building bacterial disinfection systems (nanozyme-H2O2), in which the nanozyme will promote the generation of ROS to kill bacteria based on the decomposition of H2O2. According to this criterion, a cerium oxide nanoparticle (Nanoceria, CeO2, a classical nanozyme with high peroxidase activity)-based nanozyme-H2O2 system would be very efficient for bacterial disinfection. However, CeO2 is a nanozyme with multiple enzyme-like activities. In addition to high peroxidase activity, CeO2 nanozymes also possess high superoxide dismutase activity and antioxidant activity, which can act as a ROS scavenger. Considering the fact that CeO2 nanozymes have both the activity to promote ROS production and the opposite activity for ROS scavenging, it is worth exploring which activity will play the dominating role in the CeO2-H2O2 system, as well as whether it will protect bacteria or produce an antibacterial effect. In this work, we focused on this discussion to unveil the role of CeO2 in the CeO2-H2O2 system, so that it can provide valuable knowledge for the design of a nanozyme-H2O2-based antibacterial system.

scholarly journals Manganese-Oxidizing Antarctic Bacteria (Mn-Oxb) Release Reactive Oxygen Species (ROS) as Secondary Mn(II) Oxidation Mechanisms to Avoid Toxicity

Biology ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1004
Author(s):  
Ignacio Jofré ◽  
Francisco Matus ◽  
Daniela Mendoza ◽  
Francisco Nájera ◽  
Carolina Merino
Keyword(s):  
Reactive Oxygen Species ◽  
Reactive Oxygen ◽  
Soil Formation ◽  
Ros Production ◽  
Oxygen Species ◽  
Ros Scavenging ◽  
Cell Protection ◽  
Temperature Dependent ◽  
Antarctic Soils ◽  
Dependent Mechanism

Manganese (Mn) oxidation is performed through oxidative Mn-oxidizing bacteria (MnOxb) as the main bio-weathering mechanism for Mn(III/IV) deposits during soil formation. However, with an increase in temperature, the respiration rate also increases, producing Reactive Oxygen Species (ROS) as by-products, which are harmful to microbial cells. We hypothesize that bacterial ROS oxidize Mn(II) to Mn(III/IV) as a secondary non-enzymatic temperature-dependent mechanism for cell protection. Fourteen MnOxb were isolated from Antarctic soils under the global warming effect, and peroxidase (PO) activity, ROS, and Mn(III/IV) production were evaluated for 120 h of incubation at 4 °C, 15 °C, and 30 °C. ROS contributions to Mn oxidation were evaluated in Arthrobacter oxydans under antioxidant (Trolox) and ROS-stimulated (menadione) conditions. The Mn(III/IV) concentration increased with temperature and positively correlated with ROS production. ROS scavenging with Trolox depleted the Mn oxidation, and ROS-stimulant increased the Mn precipitation in A. oxydans. Increasing the Mn(II) concentration caused a reduction in the membrane potential and bacterial viability, which resulted in Mn precipitation on the bacteria surface. In conclusion, bacterial ROS production serves as a complementary non-enzymatic temperature-dependent mechanism for Mn(II) oxidation as a response in warming environments.

Processing polymer nanocomposites with natural additives for medical applications

2019 ◽  
Vol 39 (2) ◽  
pp. 178-185
Author(s):  
Demet Topaloğlu Yazıcı ◽  
Arzu Yener
Keyword(s):  
Olive Oil ◽  
Polymer Nanocomposites ◽  
Water Uptake ◽  
High Water ◽  
Medical Applications ◽  
Drug Adsorption ◽  
Hydrophobizing Agent ◽  
Images Processing ◽  
Natural Additive ◽  
Natural Additives

Abstract The aim of this study is to analyze the effect of natural additive incorporation on processing nanocomposites and their effect on the functional characteristics of nanocomposites such as water uptake characteristics, drug adsorption and dissolution behaviors. Chitosan and montmorillonite were processed with olive oil and glycerin natural additives. In order to compare the processing results, the structure and the morphology of the polymer nanocomposites were examined by using infrared spectra, X-ray diffractograms and electron microscope images. Processing with nontoxic and healthful olive oil as a hydrophobizing agent overcame the high water uptake properties of the polymer nanocomposites and eliminated the use of other expensive chemicals. The nanocomposites without additives adsorbed the highest amounts of methylene blue at equilibrium. In vitamin B12 dissolution studies, not only the additives but also the reinforcement affected the results. Obviously, it can be seen that both the natural additive types and the reinforcement modification effects governed the drug adsorption and dissolution behaviors of the new tailored polymer nanocomposites. Moreover, the additives also improved the processing and handling abilities of these polymer nanocomposites. According to the results, these nanocomposites are promising candidates for medical applications like as a carrier for drug delivery and for skin treatment studies.

Influence of Citric Acid and Curing Time on Water Uptake

2014 ◽  
Vol 625 ◽  
pp. 123-126 ◽  
Author(s):  
Sohibatul Muizzah Mohamad Izhar ◽  
Ku Zilati Ku Shaari ◽  
Zakaria Man ◽  
Yon Norasyikin Samsudin
Keyword(s):  
Citric Acid ◽  
Water Uptake ◽  
Barrier Properties ◽  
High Water ◽  
Cross Linking ◽  
Curing Time ◽  
Gas Barrier ◽  
Water Sensitivity ◽  
Hydrophilic Character ◽  
Starch Films

Starch is highly promising biopolymer for the production of packaging material since it gives films a good tensile and gas barrier properties. However, non-plasticized starch films are brittle and their hydrophilic character results in poor moisture barrier properties and high water sensitivity. In order to improve films formation and material properties of starch, plasticization and chemical modification such as cross-linking of the starch is required. The cross-linking reaction able to improve thermal stability, tensile strength and decreased the dissolution of starch films in water and formic acid. From the study, the percentage of water uptake reduced when the blending ratio of citric acid increased.The percentage of water uptake highly affected by curing time compared to blending ratio. Increasing the curing time from 1 hour to 2 hour significantly reduced the percentage of water uptake. At 4 hour curing time, the percentage water uptake reached equilibrium faster than 3 hour curing time. This shows that more citric acid molecules were chemically bonded with the starch chains, resulting in higher cross link degree and thus, reduced the percentage of water uptake.

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