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Seyed Hajizadeh H, Azizi S, Aghaee A, Karakus S, Kaya O. Nano-silicone and Ascophyllum nodosum-based biostimulant down-regulates the negative effect of in vitro induced-salinity in Rosa damascena. BMC PLANT BIOLOGY 2023; 23:560. [PMID: 37957557 PMCID: PMC10644502 DOI: 10.1186/s12870-023-04584-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 11/06/2023] [Indexed: 11/15/2023]
Abstract
BACKGROUND Rosa damascena is extensively cultivated in various regions of Iran due to its aesthetic attributes, medicinal qualities, and essential oil production. This study investigated the efficacy of Ascophyllum nodosum extract (AnE) at concentrations of 0, 2, and 3 g L- 1 and Nano-silicon (nSiO2) at concentrations of 0, 50, and 100 mg L- 1 in ameliorating the impact of salinity on two genotypes of Damask rose ('Chaharfasl' and 'Kashan') under in vitro culture conditions. Additionally, various physio-chemical characteristics of R. damascena explants were assessed. RESULTS The findings revealed that exposure to 100 mM NaCl resulted in a substantial reduction in the Relative Water Content (RWC), Membrane Stability Index (MSI), leaf pigments (Chlorophyll b, Chlorophyll a, total Chlorophyll, and carotenoids), chlorophyll fluorescence parameters, and protein content in both genotypes when compared to control conditions. Salinity induced a significant increase in the parameter F0 and a decrease in the parameter Fv/Fm compared to the control conditions in both genotypes. Nonetheless, the genotype Kashan treated with 3 g L- 1 AnE + 100 mg L- 1 nSiO2 exhibited the maximum Fm value under control conditions, with a significant difference compared to other treatments. Furthermore, salinity caused a considerable reduction in Fm in both 'Kashan' and 'Chaharfasl' by 22% and 17%, respectively, when compared to the control condition. 'Kashan' displayed the maximum Fv/Fm compared to the other genotype. The maximum levels of Malondialdehyde (MAD) and hydrogen peroxide (H2O2) were also observed in explants affected by salinity. The combination of 3 g L- 1 AnE + 100 mg L- 1 nSiO2, followed by 2 g L- 1 AnE + 100 mg L- 1 nSiO2, exhibited substantial positive effects. Salinity also led to an increase in proline content and the activity of peroxidase (POD), superoxide dismutase (SOD), guaiacol peroxidase (GPX), and catalase (CAT) in both genotypes. The activity of these enzymes was further enhanced when AnE was applied at concentrations of 2 and 3 g L- 1 in combination with 100 mg L- 1 nSiO2. CONCLUSIONS The 'Kashan' genotype displayed greater tolerance to salinity by enhancing water balance, maintaining membrane integrity, and augmenting the activity of antioxidant enzymes compared to 'Chaharfasl'. The utilization of nSiO2 and AnE biostimulants demonstrated potential benefits for R. damascena, both under salinity and control conditions. These findings hold substantial importance for researchers, policymakers, and farmers, offering valuable insights into the development of salinity-tolerant crop varieties.
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Affiliation(s)
- Hanifeh Seyed Hajizadeh
- Department of Horticulture, Faculty of Agriculture, University of Maragheh, Maragheh, 55136-553, Iran.
| | - Sahar Azizi
- Department of Horticulture, Faculty of Agriculture, University of Maragheh, Maragheh, 55136-553, Iran
| | - Ahmad Aghaee
- Department of Biology, Faculty of Science, University of Maragheh, Maragheh, Iran
| | - Sinem Karakus
- Çölemerik Vocational School, Hakkari University, Hakkari, 30000, Turkey
- Republic of Turkey Ministry of Agriculture and Forestry, Erzincan Horticultural Research Institute, Erzincan, 24060, Turkey
| | - Ozkan Kaya
- Republic of Turkey Ministry of Agriculture and Forestry, Erzincan Horticultural Research Institute, Erzincan, 24060, Turkey
- Department of Plant Sciences, North Dakota State University, Fargo, ND, 58102, USA
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Wang YQ, Ye JJ, Yang HZ, Li D, Li XX, Wang YK, Zheng XQ, Ye JH, Li QS, Liang YR, Lu JL. Shading-Dependent Greening Process of the Leaves in the Light-Sensitive Albino Tea Plant 'Huangjinya': Possible Involvement of the Light-Harvesting Complex II Subunit of Photosystem II in the Phenotypic Characteristic. Int J Mol Sci 2023; 24:10314. [PMID: 37373460 DOI: 10.3390/ijms241210314] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 06/13/2023] [Accepted: 06/16/2023] [Indexed: 06/29/2023] Open
Abstract
The light-sensitive albino tea plant can produce pale-yellow shoots with high levels of amino acids which are suitable to process high-quality tea. In order to understand the mechanism of the albino phenotype formation, the changes in the physio-chemical characteristics, chloroplast ultrastructure, chlorophyll-binding proteins, and the relevant gene expression were comprehensively investigated in the leaves of the light-sensitive albino cultivar 'Huangjinya' ('HJY') during short-term shading treatment. In the content of photosynthetic pigments, the ultrastructure of the chloroplast, and parameters of the photosynthesis in the leaves of 'HJY' could be gradually normalized along with the extension of the shading time, resulting in the leaf color transformed from pale yellow to green. BN-PAGE and SDS-PAGE revealed that function restoration of the photosynthetic apparatus was attributed to the proper formation of the pigment-protein complexes on the thylakoid membrane that benefited from the increased levels of the LHCII subunits in the shaded leaves of 'HJY', indicating the low level of LHCII subunits, especially the lack of the Lhcb1 might be responsible for the albino phenotype of the 'HJY' under natural light condition. The deficiency of the Lhcb1 was mainly subject to the strongly suppressed expression of the Lhcb1.x which might be modulated by the chloroplast retrograde signaling pathway GUN1 (GENOMES UNCOUPLED 1)-PTM (PHD type transcription factor with transmembrane domains)-ABI4 (ABSCISIC ACID INSENSITIVE 4).
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Affiliation(s)
- Ying-Qi Wang
- Tea Research Institute, Zhejiang University, Hangzhou 310058, China
| | - Jing-Jing Ye
- Tea Research Institute, Zhejiang University, Hangzhou 310058, China
| | | | - Da Li
- Institute of Sericulture and Tea, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
| | - Xiao-Xiang Li
- Tea Research Institute, Zhejiang University, Hangzhou 310058, China
| | - Yong-Kang Wang
- Tea Research Institute, Zhejiang University, Hangzhou 310058, China
| | - Xin-Qiang Zheng
- Tea Research Institute, Zhejiang University, Hangzhou 310058, China
| | - Jian-Hui Ye
- Tea Research Institute, Zhejiang University, Hangzhou 310058, China
| | - Qing-Sheng Li
- Institute of Sericulture and Tea, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
| | - Yue-Rong Liang
- Tea Research Institute, Zhejiang University, Hangzhou 310058, China
| | - Jian-Liang Lu
- Tea Research Institute, Zhejiang University, Hangzhou 310058, China
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Pleiotropic Functions of Nitric Oxide Produced by Ascorbate for the Prevention and Mitigation of COVID-19: A Revaluation of Pauling's Vitamin C Therapy. Microorganisms 2023; 11:microorganisms11020397. [PMID: 36838362 PMCID: PMC9963342 DOI: 10.3390/microorganisms11020397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 01/30/2023] [Accepted: 01/31/2023] [Indexed: 02/08/2023] Open
Abstract
Linus Pauling, who was awarded the Nobel Prize in Chemistry, suggested that a high dose of vitamin C (l-ascorbic acid) might work as a prevention or treatment for the common cold. Vitamin C therapy was tested in clinical trials, but clear evidence was not found at that time. Although Pauling's proposal has been strongly criticized for a long time, vitamin C therapy has continued to be tested as a treatment for a variety of diseases, including coronavirus infectious disease 2019 (COVID-19). The pathogen of COVID-19, SARS-CoV-2, belongs to the β-coronavirus lineage, which includes human coronavirus, severe acute respiratory syndrome (SARS), and Middle East respiratory syndrome (MERS). This review intends to shed new light on vitamin C antiviral activity that may prevent SARS-CoV-2 infection through the chemical production of nitric oxide (NO). NO is a gaseous free radical that is largely produced by the enzyme NO synthase (NOS) in cells. NO produced by upper epidermal cells contributes to the inactivation of viruses and bacteria contained in air or aerosols. In addition to enzymatic production, NO can be generated by the chemical reduction of inorganic nitrite (NO2-), an alternative mechanism for NO production in living organisms. Dietary vitamin C, largely contained in fruits and vegetables, can reduce the nitrite in saliva to produce NO in the oral cavity when chewing foods. In the stomach, salivary nitrite can also be reduced to NO by vitamin C secreted from the epidermal cells of the stomach. The strong acidic pH of gastric juice facilitates the chemical reduction of salivary nitrite to produce NO. Vitamin C contributes in multiple ways to the host innate immune system as a first-line defense mechanism against pathogens. Highlighting chemical NO production by vitamin C, we suggest that controversies on the therapeutic effects of vitamin C in previous clinical trials may partly be due to less appreciation of the pleiotropic functions of vitamin C as a universal bioreductant.
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Borsuk AM, Roddy AB, Théroux‐Rancourt G, Brodersen CR. Structural organization of the spongy mesophyll. THE NEW PHYTOLOGIST 2022; 234:946-960. [PMID: 35037256 PMCID: PMC9303971 DOI: 10.1111/nph.17971] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 12/21/2021] [Indexed: 05/21/2023]
Abstract
Many plant leaves have two layers of photosynthetic tissue: the palisade and spongy mesophyll. Whereas palisade mesophyll consists of tightly packed columnar cells, the structure of spongy mesophyll is not well characterized and often treated as a random assemblage of irregularly shaped cells. Using micro-computed tomography imaging, topological analysis, and a comparative physiological framework, we examined the structure of the spongy mesophyll in 40 species from 30 genera with laminar leaves and reticulate venation. A spectrum of spongy mesophyll diversity encompassed two dominant phenotypes: first, an ordered, honeycomblike tissue structure that emerged from the spatial coordination of multilobed cells, conforming to the physical principles of Euler's law; and second, a less-ordered, isotropic network of cells. Phenotypic variation was associated with transitions in cell size, cell packing density, mesophyll surface-area-to-volume ratio, vein density, and maximum photosynthetic rate. These results show that simple principles may govern the organization and scaling of the spongy mesophyll in many plants and demonstrate the presence of structural patterns associated with leaf function. This improved understanding of mesophyll anatomy provides new opportunities for spatially explicit analyses of leaf development, physiology, and biomechanics.
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Affiliation(s)
| | - Adam B. Roddy
- Department of Biological SciencesInstitute of EnvironmentFlorida International UniversityMiamiFL33199USA
| | - Guillaume Théroux‐Rancourt
- Department of Integrative Biology and Biodiversity ResearchInstitute of BotanyUniversity of Natural Resources and Life Sciences, Vienna1180ViennaAustria
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Zhou R, Yu X, Huang S, Song X, Rosenqvist E, Ottosen CO. Genotype-dependent responses of chickpea to high temperature and moderately increased light. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2020; 154:353-359. [PMID: 32912481 DOI: 10.1016/j.plaphy.2020.06.030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Revised: 06/15/2020] [Accepted: 06/17/2020] [Indexed: 06/11/2023]
Abstract
Our aim was to understand how moderately increased light intensities influenced the response of chickpea to high temperature. Three chickpea genotypes (Acc#3, Acc#7 and Acc#8) were treated at control (26 °C and 300 μmol m-2 s-1 photosynthetic photon flux density/PPFD), high temperature (38 °C and 300 μmol m-2 s-1 PPFD), increased light intensity (26 °C and 600 μmol m-2 s-1 PPFD) and combination of increased light and temperature (38 °C and 600 μmol m-2 s-1 PPFD). The net photosynthetic rate (PN) of Acc#3 and Acc#8 significantly decreased at high temperature regardless of light intensity. The PN of all three genotypes at increased light intensity was significantly higher than that at high temperature. The intracellular CO2 concentration (Ci), stomatal conductance (gs) and transpiration rate (E) of Acc#3 and Acc#8 at increased light intensity with or without high temperature significantly decreased in comparison with control and individually high temperature treatment. The relative water content of Acc#3 at high temperature and the combination treatment decreased as compared with control. The relative water content of Acc#7 at control was higher than the other three treatments. The Fv/Fm (Maximum quantum efficiency of photosystem II) of leaves from the three genotypes at 38 °C were lower than at 26 °C regardless of light intensity. The high temperature decreased chlorophyll content in the lower bottom leaf of Acc#7 and Acc#8 than control. In conclusion, chickpeas showed a higher net photosynthetic rate at increased light intensity to withstand heat stress, which was genotype-dependent. Physiological responses of different chickpea genotypes to increased temperature and light intensity indicated that distinct responsive mechanism of photosynthesis. This study provides information on how chickpea respond to high temperature and increased light intensity, which will help us to improve chickpea to deal with future climate changes.
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Affiliation(s)
- Rong Zhou
- Department of Food Science, Aarhus University, Aarhus, Denmark.
| | - Xiaqing Yu
- National Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Jiangsu, Nanjing, China
| | - Sijie Huang
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environmental, Nanjing, China
| | - Xiaoming Song
- College of Life Sciences, North China University of Science and Technology, Tangshan, Hebei, China
| | - Eva Rosenqvist
- Department of Plant and Environmental Sciences, University of Copenhagen, Taastrup, Denmark
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Yu J, Zhang J, Zhao Q, Liu Y, Chen S, Guo H, Shi L, Dai S. Proteomic Analysis Reveals the Leaf Color Regulation Mechanism in Chimera Hosta "Gold Standard" Leaves. Int J Mol Sci 2016; 17:346. [PMID: 27005614 PMCID: PMC4813207 DOI: 10.3390/ijms17030346] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2015] [Revised: 02/09/2016] [Accepted: 03/01/2016] [Indexed: 11/28/2022] Open
Abstract
Leaf color change of variegated leaves from chimera species is regulated by fine-tuned molecular mechanisms. Hosta "Gold Standard" is a typical chimera Hosta species with golden-green variegated leaves, which is an ideal material to investigate the molecular mechanisms of leaf variegation. In this study, the margin and center regions of young and mature leaves from Hosta "Gold Standard", as well as the leaves from plants after excess nitrogen fertilization were studied using physiological and comparative proteomic approaches. We identified 31 differentially expressed proteins in various regions and development stages of variegated leaves. Some of them may be related to the leaf color regulation in Hosta "Gold Standard". For example, cytosolic glutamine synthetase (GS1), heat shock protein 70 (Hsp70), and chloroplastic elongation factor G (cpEF-G) were involved in pigment-related nitrogen synthesis as well as protein synthesis and processing. By integrating the proteomics data with physiological results, we revealed the metabolic patterns of nitrogen metabolism, photosynthesis, energy supply, as well as chloroplast protein synthesis, import and processing in various leaf regions at different development stages. Additionally, chloroplast-localized proteoforms involved in nitrogen metabolism, photosynthesis and protein processing implied that post-translational modifications were crucial for leaf color regulation. These results provide new clues toward understanding the mechanisms of leaf color regulation in variegated leaves.
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Affiliation(s)
- Juanjuan Yu
- Development Center of Plant Germplasm Resources, College of Life and Environmental Sciences, Shanghai Normal University, Shanghai 200234, China.
- Alkali Soil Natural Environmental Science Center, Northeast Forestry University, Key Laboratory of Saline-alkali Vegetation Ecology Restoration in Oil Field, Ministry of Education, Harbin 150040, China.
| | - Jinzheng Zhang
- Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
| | - Qi Zhao
- Development Center of Plant Germplasm Resources, College of Life and Environmental Sciences, Shanghai Normal University, Shanghai 200234, China.
| | - Yuelu Liu
- Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
| | - Sixue Chen
- Department of Biology, Genetics Institute, Plant Molecular and Cellular Biology Program, Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, FL 32610, USA.
| | - Hongliang Guo
- Food Engineering College, Harbin University of Commerce, Harbin 150028, China.
| | - Lei Shi
- Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
| | - Shaojun Dai
- Development Center of Plant Germplasm Resources, College of Life and Environmental Sciences, Shanghai Normal University, Shanghai 200234, China.
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7
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Yamasaki H, Watanabe NS, Sakihama Y, Cohen MF. An Overview of Methods in Plant Nitric Oxide (NO) Research: Why Do We Always Need to Use Multiple Methods? Methods Mol Biol 2016; 1424:1-14. [PMID: 27094406 DOI: 10.1007/978-1-4939-3600-7_1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The free radical nitric oxide (NO) is a universal signaling molecule among living organisms. To investigate versatile functions of NO in plants it is essential to analyze biologically produced NO with an appropriate method. Owing to the uniqueness of NO, plant researchers may encounter difficulties in applying methods that have been developed for mammalian study. Based on our experience, we present here a practical guide to NO measurement fitted to plant biology.
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Affiliation(s)
- Hideo Yamasaki
- Faculty of Science, University of the Ryukyus, Nishihara, Okinawa, 903-0213, Japan.
| | - Naoko S Watanabe
- Faculty of Science, University of the Ryukyus, Nishihara, Okinawa, 903-0213, Japan
| | - Yasuko Sakihama
- Research Faculty of Agriculture, Hokkaido University, Kita Ku, Kita 9, Nishi 9, Sapporo, Hokkaido, 060-8589, Japan
| | - Michael F Cohen
- Department of Biology, Sonoma State University, Rohnert Park, CA, 94928, USA.,Biological Systems Unit, Okinawa Institute of Science and Technology, 1919-1 Tancha, Onna-son, Kunigami-gun, Okinawa, 904-0495, Japan
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Yaakoubi H, Hamdani S, Bekalé L, Carpentier R. Protective action of spermine and spermidine against photoinhibition of photosystem I in isolated thylakoid membranes. PLoS One 2014; 9:e112893. [PMID: 25420109 PMCID: PMC4242612 DOI: 10.1371/journal.pone.0112893] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Accepted: 10/16/2014] [Indexed: 11/18/2022] Open
Abstract
The photo-stability of photosystem I (PSI) is of high importance for the photosynthetic processes. For this reason, we studied the protective action of two biogenic polyamines (PAs) spermine (Spm) and spermidine (Spd) on PSI activity in isolated thylakoid membranes subjected to photoinhibition. Our results show that pre-loading thylakoid membranes with Spm and Spd reduced considerably the inhibition of O2 uptake rates, P700 photooxidation and the accumulation of superoxide anions (O2(-)) induced by light stress. Spm seems to be more effective than Spd in preserving PSI photo-stability. The correlation of the extent of PSI protection, photosystem II (PSII) inhibition and O2(-) generation with increasing Spm doses revealed that PSI photo-protection is assumed by two mechanisms depending on the PAs concentration. Given their antioxidant character, PAs scavenge directly the O2(-) generated in thylakoid membranes at physiological concentration (1 mM). However, for non-physiological concentration, the ability of PAs to protect PSI is due to their inhibitory effect on PSII electron transfer.
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Affiliation(s)
- Hnia Yaakoubi
- Groupe de Recherche en Biologie-Végétale, Université du Québec à Trois-Rivières, Trois-Rivières, Québec, Canada
| | - Saber Hamdani
- Groupe de Recherche en Biologie-Végétale, Université du Québec à Trois-Rivières, Trois-Rivières, Québec, Canada
| | - Laurent Bekalé
- Groupe de Recherche en Biologie-Végétale, Université du Québec à Trois-Rivières, Trois-Rivières, Québec, Canada
| | - Robert Carpentier
- Groupe de Recherche en Biologie-Végétale, Université du Québec à Trois-Rivières, Trois-Rivières, Québec, Canada
- * E-mail:
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Effect of biogenic polyamine spermine on the structure and function of photosystem I. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2014; 141:76-83. [PMID: 25318020 DOI: 10.1016/j.jphotobiol.2014.09.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2014] [Revised: 09/10/2014] [Accepted: 09/12/2014] [Indexed: 11/22/2022]
Abstract
We located the binding sites of spermine (Spm) to PSI sub-membrane proteins and the impact of this interaction on the photoprotection of PSI activity, using spectroscopic methods and molecular modeling. Our results showed that at high Spm content the polyamine binds PSI polypeptides through H-bonding and induces major protein conformational changes with the reduction of α-helix from 52% to 42% and an increase of the β-sheet from 26% to 29%. However, polyamine does not affect significantly the photooxidizable P700 in control sample and considerably protects it against strong illumination. On the contrary, protein conformational changes coincide with an important inhibition of O2 uptake rates by polyamine, which revealed that the protein of the PSI donor side plastocyanin is a main target for Spm inhibition. The photoprotection of PSI photochemical activity may be due to the stabilization of the PSI stromal polypeptides by Spm as shown by the docking results. Spm binds to different amino acids with hydrophilic and hydrophobic characters, while the presence of several H-bondings stabilizes Spm-PSI complexation.
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Mathur S, Agrawal D, Jajoo A. Photosynthesis: Response to high temperature stress. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2014; 137:116-26. [DOI: 10.1016/j.jphotobiol.2014.01.010] [Citation(s) in RCA: 352] [Impact Index Per Article: 35.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2013] [Revised: 01/10/2014] [Accepted: 01/10/2014] [Indexed: 01/06/2023]
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Wang LF. Physiological and molecular responses to variation of light intensity in rubber Tree (Hevea brasiliensis Muell. Arg.). PLoS One 2014; 9:e89514. [PMID: 24586839 PMCID: PMC3937338 DOI: 10.1371/journal.pone.0089514] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Accepted: 01/23/2014] [Indexed: 11/18/2022] Open
Abstract
Light is one of most important factors to plants because it is necessary for photosynthesis. In this study, physiological and gene expression analyses under different light intensities were performed in the seedlings of rubber tree (Hevea brasiliensis) clone GT1. When light intensity increased from 20 to 1000 µmol m(-2) s(-1), there was no effect on the maximal quantum yield of photosystem II (PSII) photochemistry (Fv/Fm), indicating that high light intensity did not damage the structure and function of PSII reaction center. However, the effective photochemical quantum yield of PSII (Y(II)), photochemical quenching coefficient (qP), electron transfer rate (ETR), and coefficient of photochemical fluorescence quenching assuming interconnected PSII antennae (qL) were increased significantly as the light intensity increased, reached a maximum at 200 µmol m(-2) s(-1), but decreased from 400 µmol m(-2) s(-1). These results suggested that the PSII photochemistry showed an optimum performance at 200 µmol m(-2) s(-1) light intensity. The chlorophyll content was increased along with the increase of light intensity when it was no more than 400 µmol m(-2) s(-1). Since increasing light intensity caused significant increase in H2O2 content and decreases in the per unit activity of antioxidant enzymes SOD and POD, but the malondialdehyde (MDA) content was preserved at a low level even under high light intensity of 1000 µmol m(-2) s(-1), suggesting that high light irradiation did not induce membrane lipid peroxidation in rubber tree. Moreover, expressions of antioxidant-related genes were significantly up-regulated with the increase of light intensity. They reached the maximum expression at 400 µmol m(-2) s(-1), but decreased at 1000 µmol m(-2) s(-1). In conclusion, rubber tree could endure strong light irradiation via a specific mechanism. Adaptation to high light intensity is a complex process by regulating antioxidant enzymes activities, chloroplast formation, and related genes expressions in rubber tree.
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Affiliation(s)
- Li-feng Wang
- Key Laboratory of Biology and Genetic Resources of Rubber Tree, Ministry of Agriculture, State Key Laboratory Incubation Base for Cultivation and Physiology of Tropical Crops, Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences, Danzhou, Hainan, China
- * E-mail:
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Takahashi S, Nakamura T, Sakamizu M, van Woesik R, Yamasaki H. Repair Machinery of Symbiotic Photosynthesis as the Primary Target of Heat Stress for Reef-Building Corals. ACTA ACUST UNITED AC 2004; 45:251-5. [PMID: 14988497 DOI: 10.1093/pcp/pch028] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
In a coral-algae symbiotic system, heat-dependent photoinhibition of photosystem II (PSII) leads to coral bleaching. When the reef-building coral Acropora digitifera was exposed to light, a moderate increase of temperature induced coral bleaching through photobleaching of algal pigments, but not through expulsion of symbiotic algae. Monitoring of PSII photoinhibition revealed that heat-dependent photoinhibition was ascribed to inhibition of the repair of photodamaged PSII, and heat susceptibility of the repair machinery varied among coral species. We conclude that the efficiency of the photosynthesis repair machinery determines the bleaching susceptibility of coral species under elevated seawater temperatures.
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