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Yoo Gyeong Park

Bio: Yoo Gyeong Park is an academic researcher from Gyeongsang National University. The author has contributed to research in topics: Light intensity & Cutting. The author has an hindex of 12, co-authored 54 publications receiving 459 citations.

Papers published on a yearly basis

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Journal ArticleDOI
TL;DR: It is hypothesized that tomato plants have a greater capacity for tolerating saline stress through the improvement of photosynthetic metabolism and chloroplast proteome expression after silicon supplementation, and silicon plays an important role in moderating damage to chloroplasts and their metabolism in saline environments.
Abstract: Tomato plants often grow in saline environments in Mediterranean countries where salt accumulation in the soil is a major abiotic stress that limits its productivity However, silicon (Si) supplementation has been reported to improve tolerance against several forms of abiotic stress The primary aim of our study was to investigate, using comparative physiological and proteomic approaches, salinity stress in chloroplasts of tomato under silicon supplementation Tomato seedlings (Solanum lycopersicum L) were grown in nutrient media in the presence or absence of NaCl and supplemented with silicon for 5 days Salinity stress caused oxidative damage, followed by a decrease in silicon concentrations in the leaves of the tomato plants However, supplementation with silicon had an overall protective effect against this stress The major physiological parameters measured in our studies including total chlorophyll and carotenoid content were largely decreased under salinity stress, but were recovered in the presence of silicon Insufficient levels of net-photosynthesis, transpiration and stomatal conductance were also largely improved by silicon supplementation Proteomics analysis of chloroplasts analyzed by 2D-BN-PAGE (second-dimensional blue native polyacrylamide-gel electrophoresis) revealed a high sensitivity of multiprotein complex proteins (MCPs) such as photosystems I (PSI) and II (PSII) to the presence of saline A significant reduction in cytochrome b6/f and the ATP-synthase complex was also alleviated by silicon during salinity stress, while the complex forms of light harvesting complex trimers and monomers (LHCs) were rapidly up-regulated Our results suggest that silicon plays an important role in moderating damage to chloroplasts and their metabolism in saline environments We therefore hypothesize that tomato plants have a greater capacity for tolerating saline stress through the improvement of photosynthetic metabolism and chloroplast proteome expression after silicon supplementation

90 citations

Journal ArticleDOI
TL;DR: The observed responses to silicon supply in high temperature stressed-plants indicate that Si, particularly in the form of K2SiO3, has a significant role in limiting the negative effects of high temperature stress by maintaining the photosynthetic proteins and stress-responsive proteins of the ascorbate glutathione defense mechanism.
Abstract: Silicon (Si) is the second most abundant element in the soil and is known to help in crop productivity. Si improves photosynthesis as well as remediates nutrient imbalances and abiotic stresses in plants. The impact and the importance of different sources, concentration, and supply of Si in improving the propagation of horticultural crops are limited. Thus, the present study focused on the supply, concentration, and source of Si on two important Korean strawberry cultivars ‘Sulhyang’ and ‘Maehyang’ under temperature stress. The high temperature (41 °C) resulted in oxidative stress in the form of H2O2 and O2 1− localizations in the -Si- and Si-treated plants as compared to 25 or 33 °C in both cultivars. However, Si, especially that from K2SiO3 source, had the ability to relieve the stress level. The immunoblots of two important photosynthetic proteins PsaA and PsbA showed decreased expression levels in the -Si plants under 41 °C temperature stress, whereas the expression levels were retained in the Si-supplied plants, particularly with K2SiO3 as the Si source. In both 25 and 33 °C, no changes in expressions of PsaA and PsbA were observed. Interestingly, the expression of three important stress-responsive proteins, superoxide dismutase (SOD), ascorbate peroxidase (APX), and catalase (CAT), were abundantly increased in the Si-treated plants under high-temperature stress (41 °C) and decreased in the –Si-treated plants except in those grown in 25 or 33 °C. The observed responses to silicon supply in high temperature stressed-plants indicate that Si, particularly in the form of K2SiO3, has a significant role in limiting the negative effects of high temperature stress by maintaining the photosynthetic proteins and stress-responsive proteins of the ascorbate glutathione defense mechanism. Moreover, these results also depict that Si application is a good way to maintain the health of plants at the propagation stage even under high temperatures of greenhouses.

51 citations

Journal ArticleDOI
TL;DR: Overall, the outcomes of this study can be utilized for the large scale production of pharmaceutically important secondary metabolites from S. kakudensis through cell suspension cultures.
Abstract: Scrophularia kakudensis is an important medicinal plant with pharmaceutically valuable secondary metabolites. To develop a sustainable source of naturaceuticals with vital therapeutic importance, a cell suspension culture was established in S. kakudensis for the first time. Friable calli were induced from the leaf explants cultured on a Murashige and Skoog (MS) medium containing 3.0 mg·L−1 6-benzyladenine (BA) in a combination with 2 mg·L−1 2,4-dichlorophenoxy acetic acid (2,4-D). From the callus cultures, a cell suspension culture was initiated and the cellular differentiation was investigated. In addition, the effect of biotic elicitors such as methyl jasmonate (MeJa), salicylic acid (SA), and sodium nitroprusside (SNP) on the accumulation of secondary metabolites and antioxidant properties was demonstrated. Among the elicitors, the MeJa elicited the accumulation of total phenols, flavonoids, and acacetin, a flavonoid compound with multiple pharmaceutical values. Similarly, the higher concentrations of the MeJa significantly modulated the activities of antioxidant enzymes and enhanced the scavenging potentials of free radicals of cell suspension extracts. Overall, the outcomes of this study can be utilized for the large scale production of pharmaceutically important secondary metabolites from S. kakudensis through cell suspension cultures.

43 citations

Journal ArticleDOI
TL;DR: In this article, the authors investigated the role of silicon on the in vitro growth and resistance to salt stress of Dianthus caryophyllus ‘Tula’ in a factorial design with 0, 50, or 100 mg·L−1 of potassium silicate (K2SiO3) in combination with NaCl.
Abstract: Although silicon (Si) is not considered as an essential element, it is beneficial to the plant growth. Its effect is more evident under abiotic and biotic stress conditions. The objective of this study is to investigate the role of Si on the in vitro growth and resistance to salt stress of Dianthus caryophyllus ‘Tula’. The experiment was designed as a factorial design with 0, 50, or 100 mg·L−1 of potassium silicate (K2SiO3) in combination with 0, 50, or 100 mM sodium chloride (NaCl). The treatment of 50 mg·L−1 Si improved the growth of plant. However, the treatment of Si at 100 mg·L−1 reduced the growth. Although NaCl retarded the growth, addition of Si along with NaCl to the culture medium mitigated the effect of NaCl. A primary defense line by Si to overcome the photosynthetic depression was apparent from the increased chlorophyll content in the Si + NaCl treatment as compared to the treatment of NaCl alone. Enhancement of growth and resistance to salinity by Si was thought to be due to the modulation in activity of antioxidant enzymes, such as superoxide dismutase, ascorbate peroxidase, guaiacol peroxidase, and catalase. Therefore, our results suggested that 50 mg·L−1 Si supplementation could be optimal for improved growth in vitro and enhanced resistance against salinity in D. caryophyllus ‘Tula’.

41 citations

Journal ArticleDOI
TL;DR: The results suggested that the RBW which provided a wider spectrum of PAR and the highest CO2 concentration provided the most the suitable environment condition for vegetative growth of lettuce among the tested light sources.
Abstract: The effect of light source and CO2 concentration on the growth and anthocyanin content of lettuce (Lactuca sativa L. ‘Seonhong Jeokchukmyeon’) grown in growth chambers was examined. The plant was grown under 140 μmol· m−2·s−1 PPF provided by either cool white fluorescent lamps (F, the control), white (W) light emitting diodes (LEDs), or a 8:1:1 mixture of red, blue and white (RBW) LEDs. Carbon dioxide concentration of the atmosphere was maintained at either 350, 700, or 1,000 μmol·mol−1. The RBW treatment promoted vegetative growth of the shoot and root. Chlorophyll fluorescence (Fv/Fm) was not significantly affected by the light source and CO2 concentration. Total anthocyanin content of the plant supplied with 1,000 mol·mol−1 CO2 was the greatest in the F treatment. Photosynthetic rate significantly increased with the increasing CO2 concentration. These results suggested that the RBW which provided a wider spectrum of PAR and the highest CO2 concentration provided the most the suitable environment condition for vegetative growth of lettuce among the tested light sources. To obtain plants with even higher quality, especially having greater content of anthocyanin, however, more considerations on supplemental light source including white LED are necessary in terms of optimum intensity, photoperiod, and optimum ratios of mixing with other LEDs.

38 citations


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TL;DR: It is argued that much of the empirical evidence, in particular that derived from recent functional genomics, is at odds with many of the mechanistic assertions surrounding Si's role, and proposes a working model, which is proposed, the 'apoplastic obstruction hypothesis', which attempts to unify the various observations on Si's beneficial influences on plant growth and yield.
Abstract: Contents Summary 67 I. Introduction 68 II. Silicon transport in plants: to absorb or not to absorb 69 III. The role of silicon in plants: not just a matter of semantics 71 IV. Silicon and biotic stress: beyond mechanical barriers and defense priming 76 V. Silicon and abiotic stress: a proliferation of proposed mechanisms 78 VI. The apoplastic obstruction hypothesis: a working model 79 VII. Perspectives and conclusions 80 Acknowledgements 81 References 81 SUMMARY: Silicon (Si) is not classified as an essential plant nutrient, and yet numerous reports have shown its beneficial effects in a variety of species and environmental circumstances. This has created much confusion in the scientific community with respect to its biological roles. Here, we link molecular and phenotypic data to better classify Si transport, and critically summarize the current state of understanding of the roles of Si in higher plants. We argue that much of the empirical evidence, in particular that derived from recent functional genomics, is at odds with many of the mechanistic assertions surrounding Si's role. In essence, these data do not support reports that Si affects a wide range of molecular-genetic, biochemical and physiological processes. A major reinterpretation of Si's role is therefore needed, which is critical to guide future studies and inform agricultural practice. We propose a working model, which we term the 'apoplastic obstruction hypothesis', which attempts to unify the various observations on Si's beneficial influences on plant growth and yield. This model argues for a fundamental role of Si as an extracellular prophylactic agent against biotic and abiotic stresses (as opposed to an active cellular agent), with important cascading effects on plant form and function.

381 citations

Journal ArticleDOI
TL;DR: The potential for improving plant resistance to drought and salt stress by Si application is highlighted and a theoretical basis for application of Si in saline soils and arid and semiarid regions worldwide is provided.
Abstract: Drought and salinity are the main abiotic stresses limiting crop yield and quality worldwide. Improving food production in drought- and salt-prone areas is the key to meet the increasing food demands in near future. It has been widely reported that silicon (Si), a second most abundant element in soil, could reduce drought and salt stress in plants. Here, we reviewed the emerging role of Si in enhancing drought and salt tolerance in plants and highlighted the mechanisms through which Si could alleviate both drought and salt stress in plants. Silicon application increased plant growth, biomass, photosynthetic pigments, straw and grain yield, and quality under either drought or salt stress. Under both salt and drought stress, the key mechanisms evoked are nutrient elements homeostasis, modification of gas exchange attributes, osmotic adjustment, regulating the synthesis of compatible solutes, stimulation of antioxidant enzymes, and gene expression in plants. In addition, Si application decreased Na+ uptake and translocation while increased K+ uptake and translocation under salt stress. However, these mechanisms vary with plant species, genotype, growth conditions, duration of stress imposed, and so on. This review article highlights the potential for improving plant resistance to drought and salt stress by Si application and provides a theoretical basis for application of Si in saline soils and arid and semiarid regions worldwide. This review article also highlights the future research needs about the role of Si under drought stress and in saline soils.

320 citations

Journal ArticleDOI
TL;DR: This review highlights recently published results on the effect of LEDs on microalgal physiology and biochemistry and how this knowledge can be applied in selecting different LEDs with specific technical properties for regulating biomass production by microalgae belonging to diverse taxonomic groups.

272 citations

Journal ArticleDOI
TL;DR: Investigation of the effects of Si on root water uptake and its role in decreasing oxidative damage in relation to root hydraulic conductance in tomato showed that Si addition ameliorated the inhibition in tomato growth and photosynthesis, and improved water status under water stress.
Abstract: Silicon (Si) can improve drought tolerance in plants, but the mechanism is still not fully understood. Previous research has been concentrating on Si’s role in leaf water maintenance in Si accumulators, while little information is available on its role in water uptake and in less Si-accumulating plants. Here, we investigated the effects of Si on root water uptake and its role in decreasing oxidative damage in relation to root hydraulic conductance in tomato (Solanum lycopersicum ‘Zhongza No.9’) under water stress. Tomato seedlings were subjected to water stress induced by 10% (w/v) polyethylene glycol-6000 in the absence or presence of 2.5 mM added silicate. The results showed that Si addition ameliorated the inhibition in tomato growth and photosynthesis, and improved water status under water stress. The root hydraulic conductance of tomato plants was decreased under water stress, and it was significantly increased by added Si. There was no significant contribution of osmotic adjustment in Si-enhanced root water uptake under water stress. The transcriptions of plasma membrane aquaporin genes were not obviously changed by Si under water stress. Water stress increased the production of reactive oxygen species and induced oxidative damage, while added Si reversed these. In addition, Si addition increased the activities of superoxide dismutase and catalase and the levels of ascorbic acid and glutathione in the roots under stress. It is concluded that Si enhances the water stress tolerance via enhancing root hydraulic conductance and water uptake in tomato plants. Si-mediated decrease in membrane oxidative damage may have contributed to the enhanced root hydraulic conductance.

172 citations