scholarly journals Ascorbic Acid-Induced Photosynthetic Adaptability of Processing Tomatoes to Salt Stress Probed by Fast OJIP Fluorescence Rise

2021 ◽  
Vol 12 ◽  
Author(s):  
Xianjun Chen ◽  
Yan Zhou ◽  
Yundan Cong ◽  
Pusheng Zhu ◽  
Jiayi Xing ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Salt Stress ◽  
Excitation Energy ◽  
Fluorescence Intensity ◽  
Heat Dissipation ◽  
Variable Fluorescence ◽  
Fluorescence Rise ◽  
Relative Variable ◽  
Relative Variable Fluorescence ◽  
Processing Tomatoes

In this study, the protective role of exogenous ascorbic acid (AsA) on salt-induced inhibition of photosynthesis in the seedlings of processing tomatoes under salt stress has been investigated. Plants under salt stress (NaCl, 100 mmol/L) were foliar-sprayed with AsA (0.5 mmol/L), lycorine (LYC, 0.25 mmol/L, an inhibitor of key AsA synthesis enzyme l-galactono-γ-lactone dehydrogenase activity), or AsA plus LYC. The effects of AsA on fast OJIP fluorescence rise curve and JIP parameters were then examined. Our results demonstrated that applying exogenous AsA significantly changed the composition of O-J-I-P fluorescence transients in plants subjected to salt stress both with and without LYC. An increase in basal fluorescence (Fo) and a decrease in maximum fluorescence (Fm) were observed. Lower K- and L-bands and higher I-band were detected on the OJIP transient curves compared, respectively, with salt-stressed plants with and without LYC. AsA application also significantly increased the values of normalized total complementary area (Sm), relative variable fluorescence intensity at the I-step (VI), absorbed light energy (ABS/CSm), excitation energy (TRo/CSm), and reduction energy entering the electron transfer chain beyond QA (ETo/CSm) per reaction centre (RC) and electron transport flux per active RC (ETo/RC), while decreasing some others like the approximated initial slope of the fluorescence transient (Mo), relative variable fluorescence intensity at the K-step (VK), average absorption (ABS/RC), trapping (TRo/RC), heat dissipation (DIo/RC) per active RC, and heat dissipation per active RC (DIo/CSm) in the presence or absence of LYC. These results suggested that exogenous AsA counteracted salt-induced photoinhibition mainly by modulating the endogenous AsA level and redox state in the chloroplast to promote chlorophyll synthesis and alleviate the damage of oxidative stress to photosynthetic apparatus. AsA can also raise the efficiency of light utilization as well as excitation energy dissipation within the photosystem II (PSII) antennae, thus increasing the stability of PSII and promoting the movement of electrons among PS1 and PSII in tomato seedling leaves subjected to salt stress.

scholarly journals The effect of storage temperature of cucumber fruit on chlorophyll fluorescence

2013 ◽  
Vol 53 (1) ◽  
pp. 57-64
Author(s):  
Ryszard Kosson
Keyword(s):  
Chlorophyll Fluorescence ◽  
Storage Temperature ◽  
Optimum Level ◽  
Variable Fluorescence ◽  
Fluorescence Measurements ◽  
Cucumber Fruit ◽  
Variable Chlorophyll Fluorescence ◽  
Relative Variable ◽  
Temperature Levels ◽  
Relative Variable Fluorescence

The effect of three storage temperature levels: 12,5°C, 20°C, and 1,5°C on basic indexes of chlorophyll fluorescence of cucumber fruits was studied. The greenhouse grown cucumber fruits cv. Wiktor F1 were stored in perforated polyethylene bags or without packages. The minimum chlorophyll fluorescence (Fo), maximum chlorophyll fluorescence (Fm), variable chlorophyll fluorescence (Fv) and relative variable fluorescence (Fv/Fm) of the cucumber peel were measured. Relative variable fluorescence was decTeasing when cucumbers were stored at temperature lower or higher than optimum level. The chlorophyll fluorescence measurements can be helpful for determination of appropriate temperature parameters of cucumber storage.

Structural and functional disorder in the photosynthetic apparatus of radish plants under magnesium deficiency

2018 ◽  
Vol 45 (6) ◽  
pp. 668 ◽  
Author(s):  
Izabela A. Samborska ◽  
Hazem M. Kalaji ◽  
Leszek Sieczko ◽  
Vasilij Goltsev ◽  
Wojciech Borucki ◽  
...  
Keyword(s):  
Magnesium Deficiency ◽  
Photosynthetic Apparatus ◽  
Dissipated Energy ◽  
Reaction Centre ◽  
Variable Fluorescence ◽  
Mg Deficiency ◽  
Chl A ◽  
Chl A Fluorescence ◽  
Relative Variable ◽  
Relative Variable Fluorescence

Magnesium (Mg) is one of the significant macronutrients which is involved in the structural stabilisation of plant tissues and many enzymes such as PSII. The latter efficiency and performance were analysed, using chlorophyll (Chl) a fluorescence induction kinetics and microscopic images, to detect the changes in structure and function of photosynthetic apparatus of radish plants grown under Mg deficiency (Mgdef). Plants grown under Mgdef showed less PSII connectivity and fewer active primary electron acceptors (QA) oxidizing reaction centres than control plants. Confocal and electron microscopy analyses showed an increased amount of starch in chloroplasts, and 3,3ʹ-diaminobenzidine (DAB)-uptake method revealed higher H2O2 accumulation under Mgdef. Prominent changes in the Chl a fluorescence parameters such as dissipated energy flux per reaction centre (DIo/RC), relative variable fluorescence at 150 μs (Vl), and the sum of the partial driving forces for the events involved in OJIP fluorescence rise (DFabs) were observed under Mg deficiency. The latter also significantly affected some other parameters such as dissipated energy fluxes per cross-section (DIo/CSo), performance index for energy conservation from photons absorbed by PSII antenna until the reduction of PSI acceptors (PItotal), and relative variable fluorescence at 300 μs (Vk). This work emphasises the use of chlorophyll fluorescence in combination with microscopic and statistical analyses to diagnose the effects of nutrients deficiency stress on plants at an early stage of its development as demonstrated for the example of Mgdef. Due to the short growth period and simple cultivation conditions of radish plant we recommend it as a new standard (model) plant to study nutrients deficiency and changes in plant photosynthetic efficiency under stress conditions.

scholarly journals Synthesis of Fluorescent Carbon Dots and Their Application in Ascorbic Acid Detection

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1246
Author(s):  
Tengfei Wang ◽  
Hui Luo ◽  
Xu Jing ◽  
Jiali Yang ◽  
Meijun Huo ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Fluorescence Intensity ◽  
Carbon Dots ◽  
Ph Dependence ◽  
Scale Up ◽  
Water Soluble ◽  
Jujube Fruit ◽  
Fluorescent Carbon Dots ◽  
Fluorescent Carbon

Water-soluble fluorescent carbon dots (CDs) were synthesized by a hydrothermal method using citric acid as the carbon source and ethylenediamine as the nitrogen source. The repeated and scale-up synthetic experiments were carried out to explore the feasibility of macroscopic preparation of CDs. The CDs/Fe3+ composite was prepared by the interaction of the CDs solution and Fe3+ solution. The optical properties, pH dependence and stability behavior of CDs or the CDs/Fe3+ composite were studied by ultraviolet spectroscopy and fluorescence spectroscopy. Following the principles of fluorescence quenching after the addition of Fe3+ and then the fluorescence recovery after the addition of asorbic acid, the fluorescence intensity of the carbon dots was measured at λex = 360 nm, λem = 460 nm. The content of ascorbic acid was calculated by quantitative analysis of the changing fluorescence intensity. The CDs/Fe3+ composite was applied to the determination of different active molecules, and it was found that the composite had specific recognition of ascorbic acid and showed an excellent linear relationship in 5.0–350.0 μmol·L−1. Moreover, the detection limit was 3.11 μmol·L−1. Satisfactory results were achieved when the method was applied to the ascorbic acid determination in jujube fruit. The fluorescent carbon dots composites prepared in this study may have broad application prospects in a rapid, sensitive and trace determination of ascorbic acid content during food processing.

scholarly journals Effect of ascorbic acid on morphological and biochemical parameters in tomato seedling exposure to salt stress

2015 ◽  
Vol 26 (2) ◽  
pp. 21-25 ◽  
Author(s):  
Marcelina Krupa-Małkiewicz ◽  
Beata Smolik ◽  
Dominik Ostojski ◽  
Maja Sędzik ◽  
Justyna Pelc
Keyword(s):  
Ascorbic Acid ◽  
Salt Stress ◽  
Biochemical Parameters ◽  
Field Conditions ◽  
Tomato Seedling ◽  
Tomato Plants ◽  
Chl A ◽  
Tomato Seedlings ◽  
Root And Shoot Length ◽  
Mda Content

AbstractThe aim of this study is to determine the effect of both NaCl and KCl alone and in comparison to AsA on the morphological and some biochemical parameters of Oxheart and Vilma cultivars of tomato under laboratory and field conditions. A combination of salt applied in the laboratory experiment caused a significant effect on seed germination and root and shoot length and a significant reduction of Chl a, Chl b and Car contents in 14-day-old tomato seedlings. However, seedlings of cultivar Vilma were characterised by higher tolerance to applied salt stress.NaCl caused a significant decrease in Chl a, Chl b and Car, and an increase in Pro and MDA content in the leaves of Vilma cultivar under field conditions. Besides, tomato plants cv. Vilma treated with NaCl alone or NaCl with ascorbic acid developed longer roots, from 48 to 73%, compared to the control.

scholarly journals The Synthesis of Ascorbic Acid in Rice Roots Plays an Important Role in the Salt Tolerance of Rice by Scavenging ROS

2018 ◽  
Vol 19 (11) ◽  
pp. 3347 ◽  
Author(s):  
Yayun Wang ◽  
Hui Zhao ◽  
Hua Qin ◽  
Zixuan Li ◽  
Hai Liu ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Ascorbic Acid ◽  
Salt Stress ◽  
Salt Tolerance ◽  
Stress Responses ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Rice Roots ◽  
Key Factor ◽  
Rna Interfering

The root plays an important role in the responses of plants to stresses, but the detailed mechanisms of roots in stress responses are still obscure. The GDP-mannose pyrophosphate synthetase (GMPase) OsVTC1-3 is a key factor of ascorbic acid (AsA) synthesis in rice roots. The present study showed that the transcript of OsVTC1-3 was induced by salt stress in roots, but not in leaves. Inhibiting the expression of OsVTC1-3 by RNA interfering (RI) technology significantly impaired the tolerance of rice to salt stress. The roots of OsVTC1-3 RI plants rapidly produced more O2−, and later accumulated amounts of H2O2 under salt stress, indicating the impaired tolerance of OsVTC1-3 RI plants to salt stress due to the decreasing ability of scavenging reactive oxygen species (ROS). Moreover, exogenous AsA restored the salt tolerance of OsVTC1-3 RI plants, indicating that the AsA synthesis in rice roots is an important factor for the response of rice to salt stress. Further studies showed that the salt-induced AsA synthesis was limited in the roots of OsVTC1-3 RI plants. The above results showed that specifically regulating AsA synthesis to scavenge ROS in rice roots was one of important factors in enhancing the tolerance of rice to salt stress.

Coumarin–nucleotide base pairs. Ultraviolet absorption, fluorescence, and photochemical study

1984 ◽  
Vol 62 (10) ◽  
pp. 2006-2010 ◽  
Author(s):  
Grażyna Wenska ◽  
Stefan Paszyc
Keyword(s):  
Excitation Energy ◽  
Fluorescence Intensity ◽  
Ultraviolet Absorption ◽  
Base Pairs ◽  
Nucleotide Base ◽  
Polymethylene Chain ◽  
Hypochromic Effect

Bichromophoric compounds containing a nucleotide base and coumarin linked with a polymethylene chain have been synthesized. A hypochromic effect was observed for adenine–coumarin pairs in contrast to the thymine containing compound. The fluorescence intensity of coumarin when bound into these systems was found to be significantly reduced. It has also been demonstrated that excitation energy is transferred from adenine or thymine to the coumarin moiety. Intermolecular dimerization of coumarin residues was observed upon irradiation of an adenine–coumarin pair.

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