scholarly journals Manipulation of light spectrum can improve the performance of photosynthetic apparatus of strawberry plants growing under salt and alkalinity stress

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0261585
Author(s):  
Majid Esmaeilizadeh ◽  
Mohammad Reza Malekzadeh Shamsabad ◽  
Hamid Reza Roosta ◽  
Piotr Dąbrowski ◽  
Marcin Rapacz ◽  
...  
Keyword(s):  
Blue Light ◽  
Red Light ◽  
Photosynthetic Apparatus ◽  
Stress Conditions ◽  
Control Treatment ◽  
Light Spectrum ◽  
Light Spectra ◽  
Intrinsic Water Use Efficiency ◽  
Use Efficiency ◽  
Metabolic Activities

Strawberry is one of the plants sensitive to salt and alkalinity stress. Light quality affects plant growth and metabolic activities. However, there is no clear answer in the literature on how light can improve the performance of the photosynthetic apparatus of this species under salt and alkalinity stress. The aim of this work was to investigate the effects of different spectra of supplemental light on strawberry (cv. Camarosa) under salt and alkalinity stress conditions. Light spectra of blue (with peak 460 nm), red (with peak 660 nm), blue/red (1:3), white/yellow (1:1) (400–700 nm) and ambient light were used as control. There were three stress treatments: control (no stress), alkalinity (40 mM NaHCO3), and salinity (80 mM NaCl). Under stress conditions, red and red/blue light had a positive effect on CO2 assimilation. In addition, blue/red light increased intrinsic water use efficiency (WUEi) under both stress conditions. Salinity and alkalinity stress decreased OJIP curves compared to the control treatment. Blue light caused an increase in its in plants under salinity stress, and red and blue/red light caused an increase in its in plants under alkalinity. Both salt and alkalinity stress caused a significant reduction in photosystem II (PSII) performance indices and quantum yield parameters. Adjustment of light spectra, especially red light, increased these parameters. It can be concluded that the adverse effects of salt and alkalinity stress on photosynthesis can be partially alleviated by changing the light spectra.

scholarly journals Blue light promotes vascular reconnection, while red light boosts the physiological response and quality of grafted watermelon seedlings

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Filippos Bantis ◽  
Emmanuel Panteris ◽  
Christodoulos Dangitsis ◽  
Esther Carrera ◽  
Athanasios Koukounaras
Keyword(s):  
Blue Light ◽  
System Development ◽  
Citrullus Lanatus ◽  
Vascular Development ◽  
Red Light ◽  
Photosynthetic Apparatus ◽  
Light Emitting ◽  
Light Spectra ◽  
Root System Development

AbstractThe wound inflicted during grafting of watermelon seedlings requires rapid and sufficient vascular development which is affected by light quality. Our objective was to investigate the effect of light spectra emitted by light-emitting diodes (LEDs) during healing of grafted watermelon (Citrullus lanatus) seedlings on their vascular development, physiological and phytohormonal profile, and root architecture. Three LEDs emitting red (R), blue (B), and RB with 12% blue (12B) were tested in a healing chamber. During the first three days, the photosynthetic apparatus portrayed by PIABS, φP0, ψE0, and ΔVIP was less damaged and faster repaired in B-treated seedlings. B and 12B promoted vascular reconnection and root development (length, surface area and volume). This was the result of signaling cascade between phytohormones such as indole-3-acetic acid and others. After vascular reconnection the seedlings switched lights for 3 more days and the picture was reversed. Seedlings treated with B for the first 3 days and R for days 4 to 6 had better photosynthetic characteristics, root system development, morphological, shoot and root biomass, and quality (i.e. Dickson’s quality index) characteristics. We concluded that blue light is important during the first 3 days of healing, while the presence of red is necessary after vascular reconnection.

scholarly journals Root Foraging Precision of Pinus pumila (Pall.) Regel Subjected to Contrasting Light Spectra

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1482
Author(s):  
Chunxia He ◽  
Jun Gao ◽  
Yan Zhao ◽  
Jing Liu
Keyword(s):  
Blue Light ◽  
Soil Nutrients ◽  
Root Morphology ◽  
Fine Root ◽  
Red Light ◽  
Pinus Pumila ◽  
Light Spectrum ◽  
Root Foraging ◽  
Light Spectra ◽  
Fine Root Morphology

Root foraging behavior in heterogeneous patterns of soil nutrients is not well understood for undergrowth in alpine forests, where light spectra may generate an interactive effect on root foraging precision. A dwarf alpine species, Pinus pumila (Pall.) Regel., was cultured in pots where nitrogen (N)–phosphorus (P)–potassium (K) nutritional granules (N–P2O5–K2O, 14–13–13) were added to both halves of an inner space at a rate of 67.5 mg N (homogeneous) or 135 mg N to a random half (heterogeneous). Potted seedlings were subjected to either a green-and-blue light spectrum with a red-to-green light ratio of 4.24 (15.3% red, 64.9% green, and 19.8% blue) or a red-light enriched spectrum (69.4% red, 30.2% green, and 0.4% blue) both at irradiations of 200.43 µmol m−2 s−1. The root foraging precision was assessed by the difference in the fine root morphology or weight between the two halves. The foraging precision was assessed by both fine root length and surface area and was promoted in seedlings subjected to the heterogeneous pattern in the red-light enriched spectrum. Seedlings subjected to the green-and-blue light spectrum showed lower shoot growth, biomass, and root morphology but had higher shoot and root N and P concentrations. The heterogenous pattern resulted in greater seedling growth and fine root morphology as well as N and P concentrations compared to the homogeneous pattern. We conclude that P. pumila has a strong ability to forage nutrients in heterogenous soil nutrients, which can be further promoted by a spectrum with higher red-light proportions.

scholarly journals The Preferences of Different Cultivars of Lettuce Seedlings (Lactuca sativa L.) for the Spectral Composition of Light

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1211
Author(s):  
Barbara Frąszczak ◽  
Monika Kula-Maximenko
Keyword(s):  
Chlorophyll Content ◽  
Blue Light ◽  
White Light ◽  
Leaf Shape ◽  
Red Light ◽  
Spectral Composition ◽  
Fresh Weight ◽  
Light Spectrum ◽  
Dark Green ◽  
Relative Chlorophyll Content

The spectrum of light significantly influences the growth of plants cultivated in closed systems. Five lettuce cultivars with different leaf colours were grown under white light (W, 170 μmol m−2 s−1) and under white light with the addition of red (W + R) or blue light (W + B) (230 μmol m−2 s−1). The plants were grown until they reached the seedling phase (30 days). Each cultivar reacted differently to the light spectrum applied. The red-leaved cultivar exhibited the strongest plasticity in response to the spectrum. The blue light stimulated the growth of the leaf surface in all the plants. The red light negatively influenced the length of leaves in the cultivars, but it positively affected their number in red and dark-green lettuce. It also increased the relative chlorophyll content and fresh weight gain in the cultivars containing anthocyanins. When the cultivars were grown under white light, they had longer leaves and higher value of the leaf shape index. The light-green cultivars had a greater fresh weight. Both the addition of blue and red light significantly increased the relative chlorophyll content in the dark-green cultivar. The spectrum enhanced with blue light had positive influence on most of the parameters under analysis in butter lettuce cultivars. These cultivars were also characterised by the highest absorbance of blue light.

scholarly journals Photosynthetic Physiology of Blue, Green, and Red Light: Light Intensity Effects and Underlying Mechanisms

2021 ◽  
Vol 12 ◽  
Author(s):  
Jun Liu ◽  
Marc W. van Iersel
Keyword(s):  
Blue Light ◽  
Interactive Effect ◽  
Red Light ◽  
Green Light ◽  
Photosynthetic Photon Flux Density ◽  
Interactive Effects ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Light Spectrum ◽  
Response Curves

Red and blue light are traditionally believed to have a higher quantum yield of CO2 assimilation (QY, moles of CO2 assimilated per mole of photons) than green light, because green light is absorbed less efficiently. However, because of its lower absorptance, green light can penetrate deeper and excite chlorophyll deeper in leaves. We hypothesized that, at high photosynthetic photon flux density (PPFD), green light may achieve higher QY and net CO2 assimilation rate (An) than red or blue light, because of its more uniform absorption throughtout leaves. To test the interactive effects of PPFD and light spectrum on photosynthesis, we measured leaf An of “Green Tower” lettuce (Lactuca sativa) under red, blue, and green light, and combinations of those at PPFDs from 30 to 1,300 μmol⋅m–2⋅s–1. The electron transport rates (J) and the maximum Rubisco carboxylation rate (Vc,max) at low (200 μmol⋅m–2⋅s–1) and high PPFD (1,000 μmol⋅m–2⋅s–1) were estimated from photosynthetic CO2 response curves. Both QYm,inc (maximum QY on incident PPFD basis) and J at low PPFD were higher under red light than under blue and green light. Factoring in light absorption, QYm,abs (the maximum QY on absorbed PPFD basis) under green and red light were both higher than under blue light, indicating that the low QYm,inc under green light was due to lower absorptance, while absorbed blue photons were used inherently least efficiently. At high PPFD, the QYinc [gross CO2 assimilation (Ag)/incident PPFD] and J under red and green light were similar, and higher than under blue light, confirming our hypothesis. Vc,max may not limit photosynthesis at a PPFD of 200 μmol m–2 s–1 and was largely unaffected by light spectrum at 1,000 μmol⋅m–2⋅s–1. Ag and J under different spectra were positively correlated, suggesting that the interactive effect between light spectrum and PPFD on photosynthesis was due to effects on J. No interaction between the three colors of light was detected. In summary, at low PPFD, green light had the lowest photosynthetic efficiency because of its low absorptance. Contrary, at high PPFD, QYinc under green light was among the highest, likely resulting from more uniform distribution of green light in leaves.

scholarly journals Effects of photoperiod and light spectra on growth and pigment composition of the green macroalga Codium tomentosum

2020 ◽  
Author(s):  
Rúben Marques ◽  
Sónia Cruz ◽  
Ricardo Calado ◽  
Ana Lillebø ◽  
Helena Abreu ◽  
...  
Keyword(s):  
Growth Rate ◽  
Relative Growth Rate ◽  
Blue Light ◽  
Early Development ◽  
Red Light ◽  
Pigment Composition ◽  
Relative Growth ◽  
Light Spectra ◽  
Short Day ◽  
Long Day

Abstract Codium tomentosum is a marine green macroalga with multiple value-added applications that is being successfully used as an extractive species in sustainable integrated multi-trophic aquaculture systems. Nonetheless, growth conditions of this species at an early development phase still require optimization. The present study addresses, under controlled laboratory conditions, the effects of photoperiod (long vs. short-day) and light spectra (white, blue, and red light) on growth and pigment composition of C. tomentosum. Relative growth rate was approximately 2× higher under long-day photoperiod (average of 39.2 and 20.1% week−1 for long and short-day, respectively). Concentrations per dry weight of major pigments such as chlorophyll a (Chla) and siphonoxanthin (Siph) were significantly higher under long-day photoperiod. Relative growth rates were higher under red light, intermediate under white light, and lower under blue light. These last results were rather surprising, as Siph-Chla/Chlb light harvesting complexes of Codium have increased absorption in the blue-green region of the light spectra. Changes in carbon allocation patterns caused by the spectral composition of light and overgrowth of green microalgae in blue light cultures could explain the differences recorded for relative growth rate. Long-day photoperiod and light sources with preferential emission at the red region of the light spectra were identified as optimal for growth of C. tomentosum at early development stages. These lighting conditions can reduce the time required to reach the necessary biomass before transfer to grow-out systems. Overall, these findings can shorten production time, increase macroalgal productivity, and enhance aquaculture revenues.

scholarly journals Seeing the Light: The Roles of Red- and Blue-Light Sensing in Plant Microbes

2018 ◽  
Vol 56 (1) ◽  
pp. 41-66 ◽  
Author(s):  
Gwyn A. Beattie ◽  
Bridget M. Hatfield ◽  
Haili Dong ◽  
Regina S. McGrane
Keyword(s):  
Blue Light ◽  
Molecular Mechanisms ◽  
Red Light ◽  
Light Availability ◽  
Photosynthetic Apparatus ◽  
Light Regulation ◽  
Environmental Signals ◽  
Light Sensing ◽  
Fungal Phytopathogens ◽  
Bacteria And Fungi

Plants collect, concentrate, and conduct light throughout their tissues, thus enhancing light availability to their resident microbes. This review explores the role of photosensing in the biology of plant-associated bacteria and fungi, including the molecular mechanisms of red-light sensing by phytochromes and blue-light sensing by LOV (light-oxygen-voltage) domain proteins in these microbes. Bacteriophytochromes function as major drivers of the bacterial transcriptome and mediate light-regulated suppression of virulence, motility, and conjugation in some phytopathogens and light-regulated induction of the photosynthetic apparatus in a stem-nodulating symbiont. Bacterial LOV proteins also influence light-mediated changes in both symbiotic and pathogenic phenotypes. Although red-light sensing by fungal phytopathogens is poorly understood, fungal LOV proteins contribute to blue-light regulation of traits, including asexual development and virulence. Collectively, these studies highlight that plant microbes have evolved to exploit light cues and that light sensing is often coupled with sensing other environmental signals.

scholarly journals Transcriptomic and Metabolomic Profiling Reveals the Effect of LED Light Quality on Fruit Ripening and Anthocyanin Accumulation in Cabernet Sauvignon Grape

2021 ◽  
Vol 8 ◽  
Author(s):  
Peian Zhang ◽  
Suwen Lu ◽  
Zhongjie Liu ◽  
Ting Zheng ◽  
Tianyu Dong ◽  
...  
Keyword(s):  
Blue Light ◽  
White Light ◽  
Plant Traits ◽  
Soluble Sugars ◽  
Red Light ◽  
Green Light ◽  
Grape Berries ◽  
Light Spectra ◽  
Metabolomic Profiling ◽  
Highly Expressed Genes

Different light qualities have various impacts on the formation of fruit quality. The present study explored the influence of different visible light spectra (red, green, blue, and white) on the formation of quality traits and their metabolic pathways in grape berries. We found that blue light and red light had different effects on the berries. Compared with white light, blue light significantly increased the anthocyanins (malvidin-3-O-glucoside and peonidin-3-O-glucoside), volatile substances (alcohols and phenols), and soluble sugars (glucose and fructose), reduced the organic acids (citric acid and malic acid), whereas red light achieved the opposite effect. Transcriptomics and metabolomics analyses revealed that 2707, 2547, 2145, and 2583 differentially expressed genes (DEGs) and (221, 19), (254, 22), (189, 17), and (234, 80) significantly changed metabolites (SCMs) were filtered in the dark vs. blue light, green light, red light, and white light, respectively. According to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses, most of the DEGs identified were involved in photosynthesis and biosynthesis of flavonoids and flavonols. Using weighted gene co-expression network analysis (WGCNA) of 23410 highly expressed genes, two modules significantly related to anthocyanins and soluble sugars were screened out. The anthocyanins accumulation is significantly associated with increased expression of transcription factors (VvHY5, VvMYB90, VvMYB86) and anthocyanin structural genes (VvC4H, Vv4CL, VvCHS3, VvCHI1, VvCHI2, VvDFR), while significantly negatively correlated with VvPIF4. VvISA1, VvISA2, VvAMY1, VvCWINV, VvβGLU12, and VvFK12 were all related to starch and sucrose metabolism. These findings help elucidate the characteristics of different light qualities on the formation of plant traits and can inform the use of supplemental light in the field and after harvest to improve the overall quality of fruit.

Enhanced Microalgal Lipid Production in Internally Illuminated Airlift Photobioreactor

2019 ◽  
Vol 53 (2) ◽  
pp. 38-45
Author(s):  
Irem Deniz ◽  
Zeliha Demirel ◽  
Esra Imamoglu ◽  
Meltem Conk Dalay
Keyword(s):  
Fatty Acids ◽  
Growth Rate ◽  
Blue Light ◽  
Lipid Content ◽  
White Light ◽  
Lipid Production ◽  
Red Light ◽  
Light Spectrum ◽  
Light Supply ◽  
Total Fatty Acids

AbstractInternal illumination systems are being considered for use as an alternative light supply technique in microalgal products. The main goal of the study was to analyze the roles of different light wavelengths in internally illuminated airlift photobioreactors (PBRs) providing the light energy in an efficient way for the biomass production, lipid yield, and fatty acid composition of Amphora capitellata. The maximum chlorophyll-a concentration per unit biomass (2.62 ± 0.16 mg L−1) was obtained under red light, which was only 14% higher than under blue light in internally illuminated airlift PBR, whereas low chlorophyll-a content was found under white light. Maximum specific growth rate of 0.317 day−1, which corresponded to a doubling time of 2.185 days, was obtained under red light for A. capitellata. It was found that lipid content increased with decreasing growth rate for A. capitellata. Palmitic acid (C16:0) and palmitoleic acid (C16:1) were the principal fatty acids accounting for between 31%‐33% and 31%‐32% of total fatty acids, respectively. It is important to underline that red and blue light spectrum ranges contribute to improved biomass growth, whereas white light has the potential to support lipid content of diatoms.

scholarly journals The Physiological Response of Lettuce to Red and Blue Light Dynamics Over Different Photoperiods

2021 ◽  
Vol 11 ◽  
Author(s):  
Giedrė Samuolienė ◽  
Akvilė Viršilė ◽  
Jurga Miliauskienė ◽  
Perttu J. Haimi ◽  
Kristina Laužikė ◽  
...  
Keyword(s):  
Blue Light ◽  
Physiological Response ◽  
Nutritive Value ◽  
Leaf Gas Exchange ◽  
Soluble Sugar ◽  
Soluble Sugars ◽  
Red Light ◽  
Antioxidant Properties ◽  
Photon Flux ◽  
Light Spectrum

This study aimed to evaluate the effect of dynamic red and blue light parameters on the physiological responses and key metabolites in lettuce and also the subsequent impact of varying light spectra on nutritive value. We explored the metabolic changes in carotenes, xanthophylls, soluble sugars, organic acids, and antioxidants; the response of photosynthetic indices [photosynthetic (Pr) and transpiration (Tr) rates]; and the intracellular to ambient CO2 concentration ratios (Ci/Ca) in lettuce (Lactuca sativa L. “Lobjoits Green Cos”). They were cultivated under constant (con) or parabolic (dyn) blue (B, 452 nm) and/or red (R, 662 nm) light-emitting diode (LED) photosynthetic photon flux densities (PPFDs) at 12, 16, and 20 h photoperiods, maintaining consistent daily light integrals (DLIs) for each light component in all treatments, at 2.3 and 9.2 mol m–2 per day for blue and red light, respectively. The obtained results and principal component analysis (PCA) confirmed a significant impact of the light spectrum, photoperiod, and parabolic profiles of PPFD on the physiological response of lettuce. The 16 h photoperiod resulted in significantly higher content of xanthophylls (neoxanthin, violaxanthin, lutein, and zeaxanthin) in lettuce leaves under both constant and parabolic blue light treatments (BconRdyn 16 h and BdynRdyn 16 h, respectively). Lower PPFD levels under a 20 h photoperiod (BdynRdyn 20 h) as well as higher PPFD levels under a 12 h photoperiod (BdynRdyn 12 h) had a pronounced impact on leaf gas exchange indices (Pr, Tr, Ci/Ca), xanthophylls, soluble sugar contents, and antioxidant properties of lettuce leaves. The parabolic PPFD lighting profile over a 16 h photoperiod (BdynRdyn 16 h) led to a significant decrease in Ci/Ca, which resulted in decreased Pr and Tr, compared with constant blue or red light treatments with the same photoperiod (BconRdyn and BdynRcon 16 h). Additionally, constant blue lighting produced higher α + β-carotene and anthocyanin (ARI) content and increased carotenoid to chlorophyll ratio (CRI) but decreased biomass accumulation and antioxidant activity.

scholarly journals phyB and HY5 are Involved in the Blue Light-Mediated Alleviation of Dormancy of Arabidopsis Seeds Possibly via the Modulation of Expression of Genes Related to Light, GA, and ABA

2019 ◽  
Vol 20 (23) ◽  
pp. 5882 ◽  
Author(s):  
Marlena Stawska ◽  
Krystyna Oracz
Keyword(s):  
Seed Germination ◽  
Blue Light ◽  
Red Light ◽  
Pcr Analysis ◽  
Light Spectrum ◽  
Seed Biology ◽  
Aba Metabolism ◽  
Expression Of Genes ◽  
Gene Coding ◽  
Blue Wavelength

Light is one of the most important environmental factors regulating seed germination. It is known that light inhibits seed germination of some monocotyledonous species and that it is mostly related to the blue wavelength of the spectrum received by cryptochromes (cry). Research has also found that the red light (R) stimulates germination of dicotyledonous seeds and that this reaction involves mainly phytochromes (phy). Surprisingly, up to date, the role and the mechanism of action of blue light (BL) in seed biology of dicot plants is still very poorly understood and some questions are unexplained, e.g., whether BL plays a role in regulation of dicot seeds dormancy and/or germination? If, so what particular elements of light signaling pathway are involved in modulation of this(ese) process(es)? Also, is the BL action in regulation of dicot seeds dormancy and/or germination maybe due to changes of expression of genes related to metabolism and/or signaling of two phytohormones controlling seed-related events, such as gibberellins (GA) and abscisic acid (ABA)? To answer these intriguing questions, the combination of biological, transcriptomic, and genetic approaches was performed in this particular study. The germination tests show that freshly harvested wild type (WT) Arabidopsis thaliana Col-0 seeds are dormant and do not germinate in darkness (at 25 °C), while nondormant (after-ripened) seeds germinate well in these conditions. It is also proven that dormancy of seeds of this species is released in the presence of white and/or BL (λ = 447 nm) when placed at 25 °C. Presented here, novel results emphasize the role of BL in dormancy alleviation of dicot seeds, indicating that this wavelength of light spectrum received by phyB induces this process and that the sensitivity to this stimulus depends on the depth of seed dormancy. In addition, it is demonstrated that various elements of phy-mediated pathway can be used in response to the signal induced by BL in germinating dormant seeds of Arabidopsis. The quantitative real time PCR analysis supported by results of germination tests of WT, T-DNA insertion mutants (i.e., hy5, hfr1, and laf1) and overexpression transformants of Arabidopsis seeds (i.e., 35S:OE:HY5, 35S:OE:HYH, 35S:OE:HFR1, and 35S:OE:LAF1) revealed that the HY5 gene coding transcription factor is most probably responsible for the control of expression of genes involved in GA/ABA metabolism and/or signaling pathways during BL-dependent dormancy alleviation of Arabidopsis seeds, while biological functions of HYH and HFR1 are associated with regulation of germination. The model of BL action in regulation of dormancy alleviation and germination potential of Arabidopsis seeds is proposed.

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