scholarly journals Effects of light spectrum on morpho-physiological traits of grafted tomato seedlings

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0250210
Author(s):  
Ahmed F. Yousef ◽  
Muhammad M. Ali ◽  
Hafiz M. Rizwan ◽  
Mohamed A. A. Ahmed ◽  
Waleed M. Ali ◽  
...  
Keyword(s):  
Light Intensity ◽  
Sugar Content ◽  
Photosynthetic Apparatus ◽  
Photochemical Quenching ◽  
Effective Quantum Yield ◽  
Light Spectrum ◽  
Expression Levels ◽  
Tomato Seedlings ◽  
Psii Photochemistry ◽  
Red Led

It is already known that there are many factors responsible for the successful grafting process in plants, including light intensity. However, the influence of the spectrum of light-emitting diodes (LEDs) on this process has almost never been tested. During the pre-grafting process tomato seedlings grew for 30 days under 100 μmol m-2 s-1 of mixed LEDs (red 70%+ blue 30%). During the post-grafting period, seedlings grew for 20 days under the same light intensity but the lightening source was either red LED, mixed LEDs (red 70% + blue 30%), blue LED or white fluorescent lamps. This was done to determine which light source(s) could better improve seedling quality and increase grafting success. Our results showed that application of red and blue light mixture (R7:B3) caused significant increase in total leaf area, dry weight (total, shoot and root), total chlorophyll/carotenoid ratio, soluble protein and sugar content. Moreover, this light treatment maintained better photosynthetic performance i.e. more effective quantum yield of PSII photochemistry Y(II), better photochemical quenching (qP), and higher electron transport rate (ETR). This can be partially explained by the observed upregulation of gene expression levels of PsaA and PsbA and the parallel protein expression levels. This in turn could lead to better functioning of the photosynthetic apparatus of tomato seedlings and then to faster production of photoassimilate ready to be translocated to various tissues and organs, including those most in need, i.e., involved in the formation of the graft union.

scholarly journals Photosynthetic performance of rocket (Eruca sativa. Mill.) grown under different regimes of light intensity, quality, and photoperiod

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0257745
Author(s):  
Naif Ali Elmardy ◽  
Ahmed F. Yousef ◽  
Kui Lin ◽  
Xiwen Zhang ◽  
Muhammad Moaaz Ali ◽  
...  
Keyword(s):  
Light Intensity ◽  
Photosynthetic Performance ◽  
Photochemical Quenching ◽  
Clear Correlation ◽  
Fluorescent Light ◽  
Fluorescence Measurement ◽  
Effective Quantum Yield ◽  
Eruca Sativa ◽  
Closed Chamber ◽  
Psii Photochemistry

In recent years, much effort has been devoted to understanding the response of plants to various light sources, largely due to advances in industry light-emitting diodes (LEDs). In this study, the effect of different light modes on rocket (Eruca sativa. Mill.) photosynthetic performance and other physiological traits was evaluated using an orthogonal design based on a combination between light intensity, quality, and photoperiod factors. Some morphological and biochemical parameters and photosynthetic efficiency of the plants were analyzed. Plants grew in a closed chamber where three light intensities (160, 190, and 220 μmol m-2 s-1) provided by LEDs with a combination of different ratios of red, green, and blue (R:G:B- 7:0:3, 3:0:7, and 5:2:3) and three different photoperiods (light/dark -10/14 h, 12/12 h, and 14/10 h) were used and compared with white fluorescent light (control). This experimental setup allowed us to study the effect of 9 light modes (LM) compared to white light. The analyzes performed showed that the highest levels of chlorophyll a, chlorophyll b, and carotenoids occurred under LM4, LM3, and LM1, respectively. Chlorophyll a fluorescence measurement showed that the best effective quantum yield of PSII photochemistry Y(II), non-photochemical quenching (NPQ), photochemical quenching coefficient (qP), and electron transport ratio (ETR) were obtained under LM2. The data showed that the application of R7:G0:B3 light mode with a shorter photoperiod than 14/10 h (light/dark), regardless of the light intensity used, resulted in a significant increase in growth as well as higher photosynthetic capacity of rocket plants. Since, a clear correlation between the studied traits under the applied light modes was not found, more features should be studied in future experiments.

scholarly journals Assessment of Heat-tolerance Potential in QTL Introgressed Lines of Hybrid Rice Restorer, KMR-3R through PS-II Efficiency

2021 ◽  
pp. 258-266
Author(s):  
V. Jaldhani ◽  
D. Sanjeeva Rao ◽  
P. Beulah ◽  
B. Srikanth ◽  
P. R. Rao ◽  
...  
Keyword(s):  
High Temperature ◽  
Quantum Yield ◽  
Temperature Stress ◽  
Heat Tolerance ◽  
Photosynthetic Apparatus ◽  
High Temperature Stress ◽  
Maximum Efficiency ◽  
Photochemical Quenching ◽  
Psii Photochemistry ◽  
Heat Tolerant

Aims: To assess heat-induced PSII damage and efficiency in eight promising backcross introgression lines (BC2F6) of KMR-3R/N22 possessing qHTSF1.1 and qHTSF4.1. Study Design:  Randomized Complete Block Design (RCBD) with three replications. Place and Duration of Study: ICAR-Indian Institute of Rice Research, Hyderabad India during wet/rainy (Kharif) season 2018. Methodology: Eight ILs (BC2F6) and parents were evaluated for heat tolerance. The high- temperature stress was imposed by enclosing the crop with a poly cover tent (Polyhouse) just before the anthesis stage. The fluorescence parameters viz., maximum efficiency of PSII photochemistry (Fv/Fm), Electron transport rate (ETR), effective PSII quantum yield (ΦPSII), coefficient of photochemical quenching (qP) and coefficient of non-photochemical quenching (qN) were measured under ambient and high-temperature stress. Results: The heat-tolerance potential of ILs was assessed in terms of PSII activity. The results indicated that significant differences were observed between treatments (T), genotypes (G) and the interaction between T × G.  The physiological basis of introgressed QTLs controls the spikelet fertility by maintaining the productive and adaptive strategies in heat-tolerant QTL introgressed lines with stable photosynthetic apparatus (PSII) under high-temperature stress. Conclusion: The Fv/Fm ratio denotes the maximum quantum yield of PSII. The heat-tolerant QTL introgressed lines exhibited stable photosynthetic apparatus (PSII) and noted better performance under high-temperature stress. They may be used as donors for fluorescence traits in breeding rice for high-temperature tolerance.

scholarly journals Physiological and Phytochemical Responses of Spinach Baby Leaves Grown in a PFAL System with LEDs and Saline Nutrient Solution

Agriculture ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 574
Author(s):  
Filippos Bantis ◽  
Mariangela Fotelli ◽  
Zoran S. Ilić ◽  
Athanasios Koukounaras
Keyword(s):  
Nutrient Solution ◽  
Nutritional Quality ◽  
Sugar Content ◽  
Soluble Sugar ◽  
Maximum Yield ◽  
Photosynthetic Apparatus ◽  
Salinity Level ◽  
Carotenoid Content ◽  
Nitrate Content ◽  
Red Led

Spinach is a leafy vegetable containing a plethora of bioactive compounds. Our study aimed to evaluate the physiological (i.e., JIP-test) and phytochemical response of spinach baby leaves grown with regular or mildly saline (40 mM NaCl) nutrient solution and irradiated by four light-emitting diodes (LEDs) with broad spectra. T1 (highest red and far-red, low blue) and T3 (high red, balanced blue, green and far-red) led to a better developed photosynthetic apparatus compared to T2 (red peak in 631 nm) and T4 (highest blue and green), highlighted by PIABS and its structural components: RC/ABS, φP0, ψE0, and ΔVIP. Elevated salinity only affected the latter parameter. T1 induced the maximum yield production but also the highest nitrate content which was far below the maximum level permitted by European legislation. Regardless of salinity level, T3 enhanced total phenol, chlorophyll, and carotenoid content. T2 and T4 led to inferior nutritional quality. Non-saline nutrient solution promoted the chlorophyll and carotenoid contents and the antioxidant potential, regardless of light treatment. By contrast, soluble sugar content was enhanced by saline nutrient solution. Our study shows that physiology and nutritional quality of spinach baby leaves can be manipulated by small interplays in the light spectra and salinity level.

Acquired tolerance of the photosynthetic apparatus to photoinhibition as a result of growing Solanum lycopersicum at moderately higher temperature and light intensity

2019 ◽  
Vol 46 (6) ◽  
pp. 555 ◽  
Author(s):  
Milena T. Gerganova ◽  
Aygyun K. Faik ◽  
Maya Y. Velitchkova
Keyword(s):  
High Temperature ◽  
Quantum Yield ◽  
Light Intensity ◽  
Electron Flow ◽  
Photosynthetic Apparatus ◽  
High Light ◽  
Cyclic Electron Flow ◽  
Photochemical Quenching ◽  
Kinetics Of ◽  
Moderately High Temperature

The kinetics of photoinhibition in detached leaves from tomato plants (Solanium lycopersicum L. cv. M82) grown for 6 days under different combinations of optimal and moderately high temperature and optimal and high light intensity were studied. The inhibition of PSII was evaluated by changes in maximal quantum yield, the coefficient of photochemical quenching and the quantum yield of PSII. The changes of PSI activity was estimated by the redox state of P700. The involvement of different possible protective processes was checked by determination of nonphotochemical quenching and cyclic electron flow around PSI. To evaluate to what extent the photosynthetic apparatus and its response to high light treatment was affected by growth conditions, the kinetics of photoinhibition in isolated thylakoid membranes were also studied. The photochemical activities of both photosystems and changes in the energy distribution and interactions between them were evaluated by means of a Clark electrode and 77 K fluorescence analysis. The data showed an increased tolerance to photoinhibition in plants grown under a combination of moderately high temperature and light intensity, which was related to the stimulation of cyclic electron flow, PSI activity and rearrangements of pigment–protein complexes, leading to a decrease in the excitation energy delivered to PSII.

scholarly journals Acclimatization of photosynthetic apparatus and antioxidant metabolism to excess soil cadmium in Buddleja spp.

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Weichang Gong ◽  
Bruce L. Dunn ◽  
Yaqing Chen ◽  
Yunmei Shen
Keyword(s):  
Quantum Yield ◽  
Photosynthetic Apparatus ◽  
Photochemical Quenching ◽  
Effective Quantum Yield ◽  
Antioxidant Metabolism ◽  
Cellular Reactive Oxygen Species ◽  
Soil Cadmium ◽  
Non Photochemical Quenching ◽  
Cd Translocation ◽  
Physiological And Biochemical

AbstractHeavy metal (HM) pollutants can cause serious phytotoxicity or oxidative stress in plants. Buddleja L., commonly known as “butterfly bushes”, are frequently found growing on HM-contaminated land. However, to date, few studies have focused on the physiological and biochemical responses of Buddleja species to HM stress. In this study, potted seedlings of B. asiatica Lour. and B. macrostachya Wall. ex Benth. were subjected to various cadmium (Cd) concentrations (0, 25, 50, 100, and 200 mg kg−1) for 90 days. Both studied Buddleja species showed restricted Cd translocation capacity. Exposure to Cd, non-significant differences (p > 0.05) were observed, including quantum yield of photosystem II (PSII), effective quantum yield of PSII, photochemical quenching and non-photochemical quenching in both species between all studied Cd concentrations. Moreover, levels of cellular reactive oxygen species (ROS) significantly declined (p < 0.05) with low malondialdehyde concentrations. In B. asiatica, high superoxide dismutase and significantly enhanced (p < 0.05) peroxidase (POD) activity contributed greatly to the detoxification of excess ROS, while markedly enhanced POD activity was observed in B. macrostachya. Additionally, B. macrostachya showed higher membership function values than did B. asiatica. These results suggested that both Buddleja species exhibited high Cd resistance and acclimatization.

scholarly journals Energy-Saving LED Light Affects the Efficiency of the Photosynthetic Apparatus and Carbohydrate Content in Gerbera jamesonii Bolus ex Hook. f. Axillary Shoots Multiplied In Vitro

Biology ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1035
Author(s):  
Monika Cioć ◽  
Krzysztof Tokarz ◽  
Michał Dziurka ◽  
Bożena Pawłowska
Keyword(s):  
Energy Saving ◽  
Sugar Content ◽  
Photosynthetic Apparatus ◽  
Photochemical Quenching ◽  
Gerbera Jamesonii ◽  
Axillary Shoots ◽  
Glucose Content ◽  
Ps Ii ◽  
Led Light

An energy-saving light emitting diode (LED) system allows for adjustment of light quality, which affects plant development and metabolic processes in in vitro cultures. The study investigated the content of endogenous carbohydrates and the condition of the photosynthetic apparatus of Gerbera jamesonii Bolus ex Hook. f. Our aim was to analyze the effects of different LED light qualities—100% red light (R LED), 100% blue (B LED), a mixture of red and blue (7:3) (RB LED), and a fluorescent lamp as a control (Fl)—during the multiplication of axillary shoots. After 40 days, the culture measurements were performed using a non-invasive pulse amplitude modulation (PAM) fluorimeter. Sugar content was assessed with high performance liquid chromatography (HPLC). Two forms of free monosaccharides (glucose and fructose), two sugar alcohol derivatives (inositol and glycerol), and seven forms of free oligosaccharides were identified. Of those, glucose content was the highest. LEDs did not disturb the sugar metabolism in multiplied shoots. Their monosaccharides were three times more abundant than oligosaccharides; the same results were found in plants grown under control light. R light depleted the performance of the photosynthetic apparatus and caused its permanent damage. The RB LED spectrum ensured the most efficient non-photochemical quenching of the photosystem II (PS II) excitation state and high shoot quality.

scholarly journals Transcriptome and physiological analysis of increase in drought stress tolerance by melatonin in tomato

2021 ◽  
Author(s):  
Lu Yang ◽  
Sijia Bu ◽  
Shengxue Zhao ◽  
Ning Wang ◽  
Jiaxin Xiao ◽  
...  
Keyword(s):  
Drought Stress ◽  
Molecular Mechanisms ◽  
Maximum Efficiency ◽  
Photochemical Quenching ◽  
Physiological Parameter ◽  
Effective Quantum Yield ◽  
Melatonin Treatment ◽  
Tomato Cultivar ◽  
Chlorophyll Fluorescence Parameters ◽  
Psii Photochemistry

Abstract Drought stress seriously affects tomato growth, yield and quality. Previous reports have pointed out that melatonin (MT) can alleviate drought stress damage to tomato. To better understand the possible physiological and molecular mechanisms, chlorophyll fluorescence parameters and leaf transcriptome profiles were analyzed in the “Micro Tom” tomato cultivar with or without melatonin irrigation under normal and drought conditions. Polyethylene glycol 6000 (PEG6000) simulated continuous drought treatment reduced plant height, but melatonin treatment improved plant growth rate. Physiological parameter measurements revealed that the drought-induced decreases in maximum efficiency of photosystem II (PSII) photochemistry, the effective quantum yield of PSII, electron transfer rate, and photochemical quenching value caused by PEG6000 treatment were alleviated by melatonin treatment, which suggests a protective effect of melatonin on PSII. Comparative transcriptome analysis identified 447, 3982, 4526 and 3258 differentially expressed genes (DEGs) in the comparative groups plus-melatonin vs. minus-melatonin (no drought), drought vs. no drought (minus-melatonin), drought vs. no drought (melatonin) and plus-melatonin vs. minus-melatonin (drought), respectively. Furthermore, 101 DEGs were common to these four comparative groups. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis revealed that DEGs in the four comparative groups were involved in multiple metabolic processes and closely related to hormone signal transduction and transcription factors. These results provide new insights into a probable mechanism of the melatonin-induced protection of photosynthesis and enhancement of drought tolerance in tomato plants.

scholarly journals Effects of nitrogen supply level on photosynthesis and chlorophyll fluorescence characteristics of rice under salt stress

2019 ◽  
pp. 741
Author(s):  
Chen Xu ◽  
Qian Li ◽  
Xiaolong Liu ◽  
Hongjun Wang ◽  
Fenglou Ling
Keyword(s):  
Salt Stress ◽  
Chlorophyll Fluorescence ◽  
Photochemical Quenching ◽  
Effective Quantum Yield ◽  
Plasma Membrane Permeability ◽  
Chlorophyll Fluorescence Parameters ◽  
Nitrogen Levels ◽  
Fluorescence Characteristics ◽  
Psii Photochemistry ◽  
Lower Magnitude

The change of photosynthesis and chlorophyll fluorescence parameters of rice were studied in five nitrogen levels during tillering, booting, and heading periods under salt stress. The net photosynthetic rate (PN), stomatal conductance (gs), transpiration rate (E), apparent mesophyll conductance (AMC), effective quantum yield of PSII photochemistry (ΦPSII), electron transport rate (ETR), and photochemical quenching coefficient (qP) were significantly declined under salt stress and exhibited a lower magnitude of decline in the 2N, 1N, and 1/2N treatments respectively during tillering, booting, and heading periods. The stomatal limit value (Ls), Nonphotochemical quenching (NPQ) and plasma membrane permeability were significantly increased and exhibited a lower magnitude of increase in the 2N, 1N, and 1/2N treatments respectively during tillering, booting, and heading periods. The amount of nitrogen in the nutrient solution should be reduced 50% after the heading period to decrease salt damage to rice under salt stress.

scholarly journals Light Quality-Dependent Regulation of Non-Photochemical Quenching in Tomato Plants

Biology ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 721
Author(s):  
Magdalena Trojak ◽  
Ernest Skowron
Keyword(s):  
Photosynthetic Pigments ◽  
Photosynthetic Apparatus ◽  
Photosynthetic Performance ◽  
Photochemical Quenching ◽  
Light Spectrum ◽  
Negative Effects ◽  
Tomato Plants ◽  
Lower Amplitude ◽  
Non Photochemical Quenching

Photosynthetic pigments of plants capture light as a source of energy for photosynthesis. However, the amount of energy absorbed often exceeds its utilization, thus causing damage to the photosynthetic apparatus. Plants possess several mechanisms to minimize such risks, including non-photochemical quenching (NPQ), which allows them to dissipate excess excitation energy in the form of harmless heat. However, under non-stressful conditions in indoor farming, it would be favorable to restrict the NPQ activity and increase plant photosynthetic performance by optimizing the light spectrum. Towards this goal, we investigated the dynamics of NPQ, photosynthetic properties, and antioxidant activity in the leaves of tomato plants grown under different light qualities: monochromatic red (R), green (G), or blue (B) light (L) at 80 µmol m−2 s−1 and R:G:B = 1:1:1 (referred to as the white light (WL)) at 120 µmol m−2 s−1. The results confirm that monochromatic BL increased the quantum efficiency of PSII and photosynthetic pigments accumulation. The RL and BL treatments enhanced the NPQ amplitude and showed negative effects on antioxidant enzyme activity. In contrast, plants grown solely under GL or WL presented a lower amplitude of NPQ due to the reduced accumulation of NPQ-related proteins, photosystem II (PSII) subunit S (PsbS), PROTON GRADIENT REGULATION-LIKE1 (PGRL1), cytochrome b6f subunit f (cytf) and violaxanthin de-epoxidase (VDE). Additionally, we noticed that plants grown under GL or RL presented an increased rate of lipid peroxidation. Overall, our results indicate the potential role of GL in lowering the NPQ amplitude, while the role of BL in the RGB spectrum is to ensure photosynthetic performance and photoprotective properties.

scholarly journals Effects of Different Light Spectra on Final Biomass Production and Nutritional Quality of Two Microgreens

Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1584
Author(s):  
Stefania Toscano ◽  
Valeria Cavallaro ◽  
Antonio Ferrante ◽  
Daniela Romano ◽  
Cristina Patané
Keyword(s):  
Nutritional Quality ◽  
Light Emitting Diode ◽  
Sugar Content ◽  
Photon Flux ◽  
Nitrate Content ◽  
Light Spectrum ◽  
Chl A ◽  
Light Spectra ◽  
Red Led ◽  
Turnip Greens

To improve microgreen yield and nutritional quality, suitable light spectra can be used. Two species—amaranth (Amaranthus tricolor L.) and turnip greens (Brassica rapa L. subsp. oleifera (DC.) Metzg)—were studied. The experiment was performed in a controlled LED environment growth chamber (day/night temperatures of 24 ± 2 °C, 16 h photoperiod, and 50/60% relative humidity). Three emission wavelengths of a light-emitting diode (LED) were adopted for microgreen lighting: (1) white LED (W); (2) blue LED (B), and (3) red LED (R); the photosynthetic photon flux densities were 200 ± 5 µmol for all light spectra. The response to light spectra was often species-specific, and the interaction effects were significant. Morphobiometric parameters were influenced by species, light, and their interaction; at harvest, in both species, the fresh weight was significantly greater under B. In amaranth, Chl a was maximized in B, whereas it did not change with light in turnip greens. Sugar content varied with the species but not with the light spectra. Nitrate content of shoots greatly varied with the species; in amaranth, more nitrates were measured in R, while no difference in turnip greens was registered for the light spectrum effect. Polyphenols were maximized under B in both species, while R depressed the polyphenol content in amaranth.

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