scholarly journals Silver nanoparticles affect germination and photosynthesis in tobacco seedlings

2020 ◽  
Vol 80 (1) ◽  
Author(s):  
Renata Biba ◽  
Mirta Tkalec ◽  
Petra Cvjetko ◽  
Petra Peharec Štefanić ◽  
Sandra Šikić ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Electron Transport ◽  
Root Growth ◽  
Germination Rate ◽  
Photosynthetic Performance ◽  
Photochemical Quenching ◽  
Chemical Transformations ◽  
Fresh Weight ◽  
Relative Electron ◽  
Tobacco Seedlings

Extensive commercialization of silver nanoparticles (AgNPs) raises the risk of their accumulation in the soil-plant system. Once released into the environment, AgNPs are prone to chemical transformations, which makes it hard to determine whether their phytotoxic effects are purely NP-related or a consequence of released Ag+ ions. In this study the effects of 25, 50, 75, 100 and 150 μM AgNPs and AgNO3 on seed germination and early growth of tobacco (Nicotiana tabacum L.) seedlings were compared. Additionally, the effect on photosynthetic performance and pigment content were investigated. Germination rate and index values indicated delayed and slower germination in some AgNP treatments. Lower AgNP concentrations stimulated root growth, but induced prominent reduction in fresh weight. Contrary, all AgNO3 concentrations inhibited root growth but only the higher ones decreased fresh weight. Obtained results imply that the observed AgNP toxicity could be ascribed to NP form and can be correlated with high AgNP stability in the solid medium. On the other hand, majority of AgNP and AgNO3 treatments induced an increase in chlorophyll content which was accompanied with significantly lower values of relative electron transport rate and coefficient of photochemical quenching, implying an inhibition of the electron transport chain. Similar impact of AgNPs and AgNO3 on photosynthesis can be correlated with lower stability of AgNPs in the liquid medium, resulting in AgNP aggregation and dissolution of Ag+ ions.

scholarly journals Photomorphogenesis in the Picocyanobacterium Cyanobium gracile Includes Increased Phycobilisome Abundance Under Blue Light, Phycobilisome Decoupling Under Near Far-Red Light, and Wavelength-Specific Photoprotective Strategies

2021 ◽  
Vol 12 ◽  
Author(s):  
Gábor Bernát ◽  
Tomáš Zavřel ◽  
Eva Kotabová ◽  
László Kovács ◽  
Gábor Steinbach ◽  
...  
Keyword(s):  
Electron Transport ◽  
Growth Rates ◽  
Incident Light ◽  
Red Light ◽  
Photosynthetic Performance ◽  
State Transitions ◽  
Photochemical Quenching ◽  
Strong Light ◽  
Antenna Size ◽  
Moderate Growth

Photomorphogenesis is a process by which photosynthetic organisms perceive external light parameters, including light quality (color), and adjust cellular metabolism, growth rates and other parameters, in order to survive in a changing light environment. In this study we comprehensively explored the light color acclimation of Cyanobium gracile, a common cyanobacterium in turbid freshwater shallow lakes, using nine different monochromatic growth lights covering the whole visible spectrum from 435 to 687 nm. According to incident light wavelength, C. gracile cells performed great plasticity in terms of pigment composition, antenna size, and photosystem stoichiometry, to optimize their photosynthetic performance and to redox poise their intersystem electron transport chain. In spite of such compensatory strategies, C. gracile, like other cyanobacteria, uses blue and near far-red light less efficiently than orange or red light, which involves moderate growth rates, reduced cell volumes and lower electron transport rates. Unfavorable light conditions, where neither chlorophyll nor phycobilisomes absorb light sufficiently, are compensated by an enhanced antenna size. Increasing the wavelength of the growth light is accompanied by increasing photosystem II to photosystem I ratios, which involve better light utilization in the red spectral region. This is surprisingly accompanied by a partial excitonic antenna decoupling, which was the highest in the cells grown under 687 nm light. So far, a similar phenomenon is known to be induced only by strong light; here we demonstrate that under certain physiological conditions such decoupling is also possible to be induced by weak light. This suggests that suboptimal photosynthetic performance of the near far-red light grown C. gracile cells is due to a solid redox- and/or signal-imbalance, which leads to the activation of this short-term light acclimation process. Using a variety of photo-biophysical methods, we also demonstrate that under blue wavelengths, excessive light is quenched through orange carotenoid protein mediated non-photochemical quenching, whereas under orange/red wavelengths state transitions are involved in photoprotection.

scholarly journals Providing an additional electron sink by the introduction of cyanobacterial flavodiirons enhances the growth of Arabidopsis thaliana in varying light

2020 ◽  
Author(s):  
Suresh Tula ◽  
Fahimeh Shahinnia ◽  
Michael Melzer ◽  
Twan Rutten ◽  
Rodrigo Gómez ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Electron Transport ◽  
Photosystem I ◽  
Photosynthetic Electron Transport ◽  
Photosynthetic Performance ◽  
Growth Potential ◽  
Photochemical Quenching ◽  
Transport Chain ◽  
Non Photochemical Quenching ◽  
Electron Sink

AbstractThe ability of plants to maintain photosynthesis in a dynamically changing environment is of central importance for their growth. As their photosynthetic machinery typically cannot adapt rapidly to fluctuations in the intensity of radiation, the level of photosynthetic efficiency is not always optimal. Cyanobacteria, algae, non-vascular plants (mosses and liverworts) and gymnosperms all produce flavodiirons (Flvs), a class of proteins not represented in the angiosperms; these proteins act to mitigate the photoinhibition of photosystem I. Here, genes specifying two cyanobacterial Flvs have been expressed in the chloroplasts of Arabidopsis thaliana in an attempt to improve the robustness of Photosystem I (PSI). The expression of Flv1 and Flv3 together shown to enhance the efficiency of the utilization of light and to boost the plant’s capacity to accumulate biomass. Based on an assessment of the chlorophyll fluorescence in the transgenic plants, the implication was that photosynthetic activity (including electron transport flow and non-photochemical quenching during a dark-to-light transition) was initiated earlier in the transgenic than in wild type plants. The improved photosynthetic performance of the transgenics was accompanied by an increased production of ATP, an acceleration of carbohydrate metabolism and a more pronounced partitioning of sucrose into starch. The indications are that Flvs are able to establish an efficient electron sink downstream of PSI, thereby ensuring that the photosynthetic electron transport chain remains in a more oxidized state. The expression of Flvs in a plant acts to both protect photosynthesis and to control the ATP/NADPH ratio; together, their presence is beneficial for the plant’s growth potential.

scholarly journals Germination and Seedling Growth Response of Sprouts and Leafy Vegetables after Applying Oxygen Nanobubble Water

2021 ◽  
Vol 24 (6) ◽  
pp. 609-617
Author(s):  
Seo Youn Lee ◽  
Seo Hee Jung ◽  
Ah Ram Cho ◽  
Myung Syun Shim ◽  
You Kyung Chung ◽  
...  
Keyword(s):  
Seed Germination ◽  
Root Growth ◽  
Plant Biomass ◽  
Leaf Growth ◽  
Germination Rate ◽  
Dry Weight ◽  
Control Plot ◽  
Leafy Vegetables ◽  
Fresh Weight ◽  
Pak Choi

Background and objective: The nanobubbles remain stable in water, and it increased dissolved oxygen (DO) in the water that promotes the seed germination and the plant growth. We evaluated the seed germination and growth of sprouts (radish, wheat, and barley) and leafy vegetables (red mustard and pak choi) when irrigated with various DO of nanobubble water (NB).Methods: The oxygen NB was generated by surface friction and treated in 4 levels: NB 0% (control, DO 9.21 mg·L-1), NB 20% (DO 15.40 mg·L-1), NB 33% (DO 20.93 mg·L-1), and NB 100% (DO 39.29 mg·L-1).Results: The root length of radish and wheat increased more in NB 33% than the control plot. The fresh weight increased in NB 33% compared to the control plot in radish and wheat, and both fresh and dry weight increased more in NB 20%, NB 33%, and NB 100% than the control plot of barley. The leaf length and width of red mustard decreased more in NB 33% and NB 100% than the control plot and NB 20%, which indicated the leaf compactness. The fresh and dry weight of shoot and root increased more in NB 100% than the control plot in red mustard. In pak choi, the shoot fresh weight increased more in NB 100% than the control plot. In leafy vegetables, the germination rate of red mustard in NB 100% was higher than the control plot, however, it was not significantly different between oxygen NB plots in sprout vegetables.Conclusion: The results showed that the root growth and biomass increased after applying NB 33% in sprout vegetables. The leaf growth properties as the number of leaves and leaf size were not significantly different or decreased in NB treatments compared to control plots, but NB 100% (DO 39.29 mg·L-1) effectively increased the root growth and plant biomass in leafy vegetables.

scholarly journals Phytotoxicity of Silver Nanoparticles on Tobacco Plants: Evaluation of Coating Effects on Photosynthetic Performance and Chloroplast Ultrastructure

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 744
Author(s):  
Petra Peharec Štefanić ◽  
Karla Košpić ◽  
Daniel Mark Lyons ◽  
Lara Jurković ◽  
Biljana Balen ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Cetyltrimethylammonium Bromide ◽  
Photosynthetic Apparatus ◽  
Chloroplast Ultrastructure ◽  
Photosynthetic Performance ◽  
Pigment Content ◽  
Inhibitory Effects ◽  
Tobacco Plants ◽  
Agriculture And Food ◽  
The Impact

Silver nanoparticles (AgNPs) are the most exploited nanomaterial in agriculture and food production, and their release into the environment raises concern about their impact on plants. Since AgNPs are prone to biotransformation, various surface coatings are used to enhance their stability, which may modulate AgNP-imposed toxic effects. In this study, the impact of AgNPs stabilized with different coatings (citrate, polyvinylpyrrolidone (PVP), and cetyltrimethylammonium bromide (CTAB)) and AgNO3 on photosynthesis of tobacco plants as well as AgNP stability in exposure medium have been investigated. Obtained results revealed that AgNP-citrate induced the least effects on chlorophyll a fluorescence parameters and pigment content, which could be ascribed to their fast agglomeration in the exposure medium and consequently weak uptake. The impact of AgNP-PVP and AgNP-CTAB was more severe, inducing a deterioration of photosynthetic activity along with reduced pigment content and alterations in chloroplast ultrastructure, which could be correlated to their higher stability, elevated Ag accumulation, and surface charge. In conclusion, intrinsic properties of AgNP coatings affect their stability and bioavailability in the biological medium, thereby indirectly contributing changes in the photosynthetic apparatus. Moreover, AgNP treatments exhibited more severe inhibitory effects compared to AgNO3, which indicates that the impact on photosynthesis is dependent on the form of Ag.

Fungal elicitor-induced retardation and its restoration of root growth in tobacco seedlings

2011 ◽  
Vol 66 (1) ◽  
pp. 59-68 ◽  
Author(s):  
Yoshio Kawaguchi ◽  
Takumi Nishiuchi ◽  
Hiraoki Kodama ◽  
Toshitsugu Nakano ◽  
Kazuma Nishimura ◽  
...  
Keyword(s):  
Root Growth ◽  
Fungal Elicitor ◽  
Tobacco Seedlings

Moderate Boron Concentration Beneficial for Flue-cured Tobacco Seedlings Growth and Development

2021 ◽  
Author(s):  
Mengxia Li ◽  
Xiaopeng Deng ◽  
Ke Ren ◽  
Rui Liu ◽  
Tao Wang ◽  
...  
Keyword(s):  
Antioxidant Enzymes ◽  
Dry Matter ◽  
Agronomic Traits ◽  
Photosynthetic Performance ◽  
Leaf Length ◽  
Internal Quality ◽  
Root Weight ◽  
Nicotine Content ◽  
Hydroponic Experiment ◽  
Tobacco Seedlings

Abstract Boron (B) is a micronutrient tobacco needs in minute amounts, and Boron insufficient supply can causes significant tobacco yield loss, however, the appropriate concentration for flue-cured tobacco seedlings to growth remains unknown. In this sense, a hydroponic experiment was conduct to measure the agronomic traits, dry matter mass, chlorophyll content, photosynthetic performance, antioxidant enzymes, boron ion and nicotine content of flue-cured tobacco seedlings K326 under different boron concentrations of 0.000mmol/L (B1, CK), 0.125mmol/L (B2), 0.250mmol/L (B3), 0.750mmol/L (B4), 5.000mmol/L (B5), 10.000mmol/L (B6), 20.000mmol/L (B7), 40.000mmol/L (B8) after 30 days. B significantly influenced flue-tobacco seedlings growth on agronomic traits, photosynthetic performance, the activities of antioxidant enzymes, boron ion and nicotine content aspects. B linearly enhanced the accumulation of boron ion by 24.00%~96.44%, and decreased nicotine content by 21.60%~82.03% in tobacco seedlings. Solution B concentration at 0.750 and 5.000mmol/L markedly improved tobacco seedlings maximum leaf length by 4.83%~82.03% and leaf width by 0.77%~24.36%, root weight by 13.64%~56.82%, stem weight by 12.26%~52.36%, leaf weight by 9.68%~36.56%, dry matter mass by 10.65%~38.92%, the Pn parameter by 1.22%~80.28%, the Cond paramete by 33.40%~75.86%, while decreased the activities of SOD by 10.44%~91.67%, POD by 21.32%~65.62% and CAT by 50.05%~96.44%, and MDA by 16.23%~75.16%. The B concentration concluded in this study enhanced the agronomy traits, photosynthetic and biochemical characteristics of flue-cured tobacco seedlings, which lays a scientific theoretical foundation for rational application of B in tobacco production and improve the internal quality of flue-cured tobacco.

scholarly journals The efficacy of different seed priming agents for promoting sorghum germination under salt stress

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0245505
Author(s):  
Xiaofei Chen ◽  
Ruidong Zhang ◽  
Yifan Xing ◽  
Bing Jiang ◽  
Bang Li ◽  
...  
Keyword(s):  
Salt Stress ◽  
Seed Germination ◽  
Germination Rate ◽  
Principal Component ◽  
Dry Weight ◽  
Seed Priming ◽  
Nacl Stress ◽  
Future Research ◽  
Fresh Weight ◽  
Positive Effects

Sorghum [Sorghum bicolor (L.) Moench] seed germination is sensitive to salinity, and seed priming is an effective method for alleviating the negative effects of salt stress on seed germination. However, few studies have compared the effects of different priming agents on sorghum germination under salt stress. In this study, we quantified the effects of priming with distilled water (HP), sodium chloride (NaCl), potassium chloride (KCl), calcium chloride (CaCl2), and polyethylene glycol (PEG) on sorghum seed germination under 150 mM NaCl stress. The germination potential, germination rate, germination index, vigor index, root length, shoot length, root fresh weight, shoot fresh weight, root dry weight, and shoot dry weight were significantly reduced by salt stress. Different priming treatments alleviated the germination inhibition caused by salt stress to varying degrees, and 50 mM CaCl2 was the most effective treatment. In addition, the mitigation effect of priming was stronger on root traits than on shoot traits. Mitigation efficacy was closely related to both the type of agent and the concentration of the solution. Principal component analysis showed that all concentrations of CaCl2 had higher scores and were clearly distinguished from other treatments based on their positive effects on all germination traits. The effects of the other agents varied with concentration. The priming treatments were divided into three categories based on their priming efficacy, and the 50, 100, and 150 mM CaCl2 treatments were placed in the first category. The 150 mM KCl, 10% PEG, HP, 150 mM NaCl, 30% PEG, and 50 mM KCl treatments were placed in the second category, and the 100 mM NaCl, 100 mM KCl, 20% PEG, and 50 mM NaCl treatments were least effective and were placed in the third category. Choosing appropriate priming agents and methods for future research and applications can ensure that crop seeds germinate healthily under saline conditions.

scholarly journals Effects of partial defoliation on the growth, ion relations and photosynthesis of Lycium chinense Mill. under salt stress

2015 ◽  
Vol 67 (4) ◽  
pp. 1185-1194 ◽  
Author(s):  
Yuan Guo ◽  
Qiong Yu ◽  
Xiaohui Feng ◽  
Zhixia Xie ◽  
Xiaojing Liu
Keyword(s):  
Salt Stress ◽  
Physiological Response ◽  
Electron Transport Rate ◽  
Dry Weight ◽  
Photochemical Quenching ◽  
Leaf Water Content ◽  
Lycium Chinense ◽  
Fresh Weight ◽  
Relative Growth ◽  
Ion Relations

In this study, we investigated the effects of artificial defoliation on the growth and physiological response of Lycium chinense Mill. to salt stress. Our results show that partial defoliation increases the plant relative growth rate, leaf water content and dry weight-based leaf Na+ content, and reduces the fresh weight-based leaf Na+ content under salt stress. In response to defoliation, the leaf Na+/Ca2+ and Na+/Mg2+ ratios were decreased, but the K+ content remained unchanged. The contents of ROS and MDA were decreased in defoliated plants. Net The photosynthetic rate (PN), stomatal conductance (gs), electron transport rate (ETR), actual photochemical quenching (?PSII) and photochemical quenching (qp) were enhanced by defoliation. Together, these findings indicate that partial defoliation mitigates the salt-induced growth inhibition and physiological damage in L. chinense.

scholarly journals Silver Nanoparticles Effects on In Vitro Germination, Growth, and Biochemical Activity of Tomato, Radish, and Kale Seedlings

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5340
Author(s):  
Alicja Tymoszuk
Keyword(s):  
Silver Nanoparticles ◽  
Practical Importance ◽  
Plant Cells ◽  
Dry Weight ◽  
Guaiacol Peroxidase ◽  
In Vitro Germination ◽  
Vegetable Crops ◽  
Fresh Weight ◽  
Biochemical Activity

The interactions between nanoparticles and plant cells are still not sufficiently understood, and studies related to this subject are of scientific and practical importance. Silver nanoparticles (AgNPs) are one of the most commonly produced and used nanomaterials. This study aimed to investigate the influence of AgNPs applied at the concentrations of 0, 50, and 100 mg·L−1 during the process of in vitro germination as well as the biometric and biochemical parameters of developed seedlings in three vegetable species: Solanum lycopersicum L. ‘Poranek’, Raphanus sativus L. var. sativus ‘Ramona’, and Brassica oleracea var. sabellica ‘Nero di Toscana’. The application of AgNPs did not affect the germination efficiency; however, diverse results were reported for the growth and biochemical activity of the seedlings, depending on the species tested and the AgNPs concentration. Tomato seedlings treated with nanoparticles, particularly at 100 mg·L−1, had shorter shoots with lower fresh and dry weights and produced roots with lower fresh weight. Simultaneously, at the biochemical level, a decrease in the content of chlorophylls and carotenoids and an increase in the anthocyanins content and guaiacol peroxidase (GPOX) activity were reported. AgNPs-treated radish plants had shorter shoots of higher fresh and dry weight and longer roots with lower fresh weight. Treatment with 50 mg·L−1 and 100 mg·L−1 resulted in the highest and lowest accumulation of chlorophylls and carotenoids in the leaves, respectively; however, seedlings treated with 100 mg·L−1 produced less anthocyanins and polyphenols and exhibited lower GPOX activity. In kale, AgNPs-derived seedlings had a lower content of chlorophylls, carotenoids, and anthocyanins but higher GPOX activity of and were characterized by higher fresh and dry shoot weights and higher heterogeneous biometric parameters of the roots. The results of these experiments may be of great significance for broadening the scope of knowledge on the influence of AgNPs on plant cells and the micropropagation of the vegetable species. Future studies should be aimed at testing lower or even higher concentrations of AgNPs and other NPs and to evaluate the genetic stability of NPs-treated vegetable crops and their yielding efficiency.

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