scholarly journals Effects of light spectra and 15N pulses on growth, leaf morphology, physiology, and internal nitrogen cycling in Quercus variabilis Blume seedlings

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0243954
Author(s):  
Jun Gao ◽  
Jinsong Zhang ◽  
Chunxia He ◽  
Qirui Wang

Light spectra of sunlight transmittance can generate an interactive effect with deposited nitrogen (N) on regenerated plants across varied shading conditions. Total N content in understory plants can be accounted for by both exogeneous and endogenous sources of derived N, but knowledge about the response of inner N cycling to interactive light and N input effects is unclear. We conducted a bioassay on Chinese cork oak (Quercus variabilis Blume) seedlings subjected to five-month N pulsing with 15NH4Cl (10.39 atom %) at 120 mg 15N plant-1 under the blue (48.5% blue, 33.7% green, and 17.8% red), red (14.6% blue, 71.7% red, 13.7% green), and green (17.4% blue, 26.2% red, 56.4% green) lighting-spectra. Half of the seedlings were fed twice a week using a 250 ppm N solution with micro-nutrients, while the other half just received distilled water. Two factors showed no interaction and neither affected growth and morphology. Compared to the red-light spectrum, that in blue light increased chlorophyll and soluble protein contents and glutamine synthetase (GS) activity, root N concentration, and N derived from the pulses. The green-light spectrum induced more biomass allocation to roots and a higher percentage of N derived from internal reserves compared to the red-light spectrum. The 15N pulses reduced the reliance on N remobilization from acorns but strengthened shoot biomass, chlorophyll content, GS activity, and N concentration. In conclusion, light spectrum imposed an independent force from external N pulse to modify the proportion of N derived from internal sources in total N content in juvenile Q. variabilis.

2020 ◽  
Author(s):  
Jun Gao ◽  
Jinsong Zhang ◽  
Chunxia He ◽  
Qirui Wang

AbstractThe light spectra that reach plants change across different shading conditions, may alter the pattern of nitrogen (N) uptake and assimilation by understory regenerations that are also exposed to N deposition. We conducted a bioassay on Chinese cork oak (Quercus variabilis Blume) seedlings subjected to five-month N pulsing with 15NH4Cl (10.39 atom %) at 120 mg 15N plant-1 under the blue (48.5% blue, 33.7% green, and 17.8% red), red (14.6% blue, 71.7% red, 13.7% green), and green (17.4% blue, 26.2% red, 56.4% green) spectra provided by light-emitting diodes (LEDs). Half of the seedlings were fed twice a week using a 250 ppm N solution with added phosphorus, potassium, and micro-nutrients, while the other half received only distilled water. Neither treatment affected growth of height, diameter, or leaf area. Compared to the red light spectrum, the blue light treatment increased chlorophyll and soluble protein contents and glutamine synthetase (GS) activity, root N concentration, and N derived from the pulses. The green light spectrum induced more biomass to allocate to the roots and a higher percentage of N derived from internal reserves compared to the other two spectra. The 15N pulses demonstrated no interaction with spectra but weakened the reliance on N remobilization from acorns, strengthened biomass allocation to shoots, and induced higher chlorophyll content, GS activity, and N concentration. In conclusion, the red light spectrum should be avoided for Q. variabilis regenerations whose biomass allocation to underground organs are weakened under this condition.


2021 ◽  
Vol 12 ◽  
Author(s):  
Jun Liu ◽  
Marc W. van Iersel

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.


2021 ◽  
Vol 8 ◽  
Author(s):  
Peian Zhang ◽  
Suwen Lu ◽  
Zhongjie Liu ◽  
Ting Zheng ◽  
Tianyu Dong ◽  
...  

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.


PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0261585
Author(s):  
Majid Esmaeilizadeh ◽  
Mohammad Reza Malekzadeh Shamsabad ◽  
Hamid Reza Roosta ◽  
Piotr Dąbrowski ◽  
Marcin Rapacz ◽  
...  

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.


Biologija ◽  
2020 ◽  
Vol 65 (4) ◽  
Author(s):  
Kateryna Reshetnyk ◽  
Yurіy Prysedsky ◽  
Dmytro Yuskov

The article presents the results of the study on the influence of laser irradiation on the development of vegetative mycelium and the period of the occurrence of the corcules of the fruit bodies of Pleurotus ostreatus. It has been established the growth processes of P. ostreatus, can be best stimulated by applying laser irradiation of mycelium with a green spectrum of light for 10 s. According to this mode of exposure, the best increase in the growth rate of mycelium of 38.3% and the appearance of the largest number of rudiments of the fruiting bodies were recorded. Laser irradiation of mycelium for 10 s with red and blue light spectrum increased the growth rate of mycelium from 7.41 to 20.4%, respectively, and the number of rudiments of the fruiting bodies increased by 1.5 to 2 times. Laser irradiation of the mycelium with 5 s, 15 s, and 20 s with red, blue, and green light spectra did not have a significant effect on the growth processes of P. ostreatus. These data open significant prospects for the modification of the existing cultivation technologies, which would increase the economic efficiency of the biotechnological cultivation process of P. ostreatus.


2019 ◽  
Vol 8 (1) ◽  
pp. 25
Author(s):  
Rizqi Umi Arifah ◽  
Sri Sedjati ◽  
Endang Supriyantini ◽  
Ali Ridlo

Skeletonema costatum mengandung klorofil-a, klorofil-c, dan fukosantin yang menyebabkan selnya berwarna hijau kecoklatan. Klorofil dan fukosantin memiliki berbagai manfaat, salah satunya dalam bidang kesehatan sebagai anti-bakteri, anti-oksidan, anti-inflamasi, anti-obesitas, anti-diabetes. Cahaya merupakan faktor lingkungan yang dapat mempengaruhi pertumbuhan dan kandungan pigmen pada mikroalga. Penelitian ini bertujuan untuk menentukan spektrum cahaya yang memiliki pengaruh terhadap pertumbuhan, kandungan klorofil dan fukosantin S. costatum. Penelitian ini dilakukan pada bulan Januari-Maret 2018 di Laboratorium Biologi, Fakultas Perikanan dan Ilmu Kelautan, Universitas Diponegoro dan pengujian laboratoris di Laboratorium BPIK Srondol, Semarang. Metode yang digunakan adalah metode eksperimental laboratoris. Diatom S. costatum dikultivasi dengan tiga spektrum cahaya yang berbeda yaitu putih, biru, dan merah. Pertumbuhan sel S. costatum diamati sampai 2 x 24 jam kemudian dipanen untuk perhitungan biomassanya. Biomassa kering hasil kultivasi diekstraksi menggunakan metanol. Kadar pigmen ekstrak metanol dianalisis menggunakan spektrofotometer UV-Vis dan identifikasi pigmen dengan uji Kromatografi Lapis Tipis (KLT). Hasil penelitian menunjukkan bahwa perlakuan cahaya putih secara signifikan meningkatkan kandungan klorofi- a S. costatum dibandingkan spektrum cahaya merah, namun tidak berbeda nyata terhadap spektrum cahaya biru. Pertumbuhan, kandungan klorofil-c dan fukosantin S. costatum pada pemberian spektrum cahaya yang berbeda tidak menunjukkan perbedaan nyata. Skeletonema costatum contains chlorophyll-a, chlorophyll-c, and fucoxanthin giving to its cells. Chlorophyll and fucoxanthin have various benefits, e.g. in the medicine field as anti-bacterial, anti-oxidant, anti-inflammatory, anti-obesity, and anti-diabetes. Light is one of the environmental factor that affects the growth and pigment content of microalgae. This study aims to determine the spectrum of light that influences growth, chlorophyll content and fucoxanthin of S. costatum. This research was conducted in January-March 2018 at the Biology Laboratory, Faculty of Fisheries and Marine Sciences, Diponegoro University and laboratory testing at the BPIK Srondol Laboratory, Semarang. The method used was a laboratory experimental method. Diatom S. costatum was cultivated with three different spectrums of light (white, blue, and red). Growth of S. costatum cells was observed up to 2x24 hours and then harvested for biomass calculations. Dry biomass was extracted using methanol. Pigment content of The S. costatum methanol extract was analyzed using UV-Vis spectrophotometer and pigments identification using Thin Layer Chromatography (TLC). The results showed that the chlorophyll content of S. costatum under white light spectrum was significantly higher from the red light spectrum, but not significantly different from blue light spectrum. Growth, chlorophyll-c and fucoxanthin content of S. costatum didn’t show significant differences under different light spectra.


Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 460
Author(s):  
Barbara Frąszczak ◽  
Beata Janowska ◽  
Dariusz Świerk

Pot marigold is a valuable medicinal plant with great decorative value. Three combinations of light (white (W)—170 μmol m−2 s−1, white + blue (W+B)—230 μmol m−2 s−1, white + red (W+R)—230 μmol m−2 s−1) were used to analyse the influence of a diversified light spectrum on the morphological traits and flowering of Calendula officinalis L. “Radio”. The effect of foliar treatment of the plants with 6-benzyladenine (BA) at concentrations of 100, 150 and 200 mg dm−3 at all the light spectrum combinations was analysed. BA had negative influence on the earliness of florescence and delayed it even by more than 10 days. W+B light intensified the delay, whereas red light partly reduced it. The BA treatment had the greatest influence on the biometric traits of the plants at the initial period of their development. W+B light significantly inhibited the growth of the plants. A high share of red light in the spectrum positively affected the Fv/Fm value, the relative chlorophyll content and the percentage of dry matter in the plants. When the amount of blue or red light in the spectrum increased, it was possible to obtain specific biometric traits of Calendula without the BA treatment.


2021 ◽  
Vol 8 (5) ◽  
pp. 145-149

Background: In the production of seedlings, success in the market is due to a quality product. Well-developed seedlings with a good root system, appear as a key factor to guarantee suitable products. Light can be used as a stimulating factor for rooting, in adequate light quality. Photoselective screens can be used to make rooting more efficient. Methods: To evaluate this factor, herbaceous cuttings of Guava Tree “Paluma” were used, exposed to different wavelengths in mini-greenhouses covered with cellophane of the colors: green, yellow, red, blue, transparent and orange, and subjected to five treatments with Indolebutyric Acid (IBA) (0, 1000, 2000, 3000 and 4000 mg.kg-1), grown in a 3: 2: 1 substrate (sand: earth: bioplant®), in a randomized block design, with a 6x5 factorial and four replications with 10 cuttings in each treatment. Ninety days after staking, the following variables were evaluated: cuttings survival, number of leaves; number of sprouts; largest sprout length; root length; root volume; green mass of leaves and root; dry mass of sprout and root. Results: The orange and red light spectra were superior in rooting the guava cuttings, and may be an option in covering the seedling production nurseries of this fruit tree. Conclusion: The use of IBA neutralized the luminous influence of the light spectra with non-significant results for the interaction.


2020 ◽  
Vol 20 (3) ◽  
pp. 281
Author(s):  
Wijianto Wijianto ◽  
Kukuh Nirmala ◽  
Yuni Puji Hastuti ◽  
Eddy Supriyono

The color quality of Sumatra barb that cultivated by the farmers are not as good as the fish that collected from the wild. One of the causes is the unsuitable environment for maintaining and breeding Sumatran barb. This research aims to compare color quality of Sumatra barb Puntigrus tetrazona by exposure the different light spectrums on maintenance media. The experiment was completely randomize design with six treatments and three replications consisted of K (control), R (room light), M (red light spectrum), H (green light spectrum), B (blue light spectrum) and P (white light spectrum). The method used to measure Sumatra barb color quality using Photoshop CS 5 software and chromatophore cell calculations. The results of color quality analysis after 28 showed that the (M) treatment had the highest percentage of color quality was 48.81 ± 1.57% for orange color and 32.26 ± 0.07% for black color. The highest number of chromatophore cells was in M treatment with 147 ± 3.7 cells mm-². The red light spectrum (M) treatment showed the best physiological response and improvement of color quality and the glucose level was 23.00 ± 1.00 mg dL−1. The best color quality of the Sumatra barb is produced by exposure to the red light spectrum (M).


HortScience ◽  
2016 ◽  
Vol 51 (2) ◽  
pp. 186-191 ◽  
Author(s):  
Xiaojie Zhao ◽  
Guihong Bi ◽  
Richard L. Harkess ◽  
Jac J. Varco ◽  
Tongyin Li ◽  
...  

Tall bearded (TB) iris (Iris germanica L.) has great potential as a specialty cut flower due to its fragrance and showy, multicolor display; however, limited research has been reported on optimal nitrogen (N) nutrient management for TB iris. The objectives of this study were to investigate the effects of N fertilizer rate on plant growth and flowering of ‘Immortality’ iris and determine the influence of both stored N and spring-applied N fertilizer on spring growth and flowering. On 14 Mar. 2012, rhizomes of ‘Immortality’ iris were potted in a commercial substrate with no starter fertilizer. Plants were fertigated with 0, 5, 10, 15, or 20 mm N from NH4NO3 twice per week from 28 Mar. to 28 Sept. 2012. In 2013, half of the plants from each of the 2012 N rate were supplied with either 0 or 10 mm N from 15NH415NO3 twice per week from 25 Mar. to 7 May 2013. Growth and flowering data including plant height, leaf SPAD, number of fans and inflorescence stems, and length of inflorescence stem were collected during the growing season. Plants were harvested in Dec. 2012 and May 2013 to measure dry weight and N concentration in leaves, roots, and rhizomes. Results showed higher 2012 N rates increased plant height, leaf SPAD reading, and number of inflorescence stems at first and second blooming in 2012. Greater 2012 N rates also increased plant dry weight and N content in all structures, and N concentration in roots and rhizomes. Rhizomes (58.8% to 66.3% of total N) were the dominant sink for N in Dec. 2012. Higher 2012 N rates increased plant height, number of fans, and the number of inflorescence stems at spring bloom in 2013. In May 2013, N in leaf tissue constituted the majority (51% to 64.3%) of the total plant N. Higher 2012 N rates increased total dry weight, N concentration, and N content in all 2013 15N rates; however, leaf dry weight in all plants was improved by 2013 15N rate. Percentage of tissue N derived from 2013 15N (NDFF) decreased with increasing 2012 N rate. New spring leaves were the dominant sink (56.8% to 72.2%) for 2013 applied 15N. In summary, ‘Immortality’ iris is capable of a second blooming in a growing season, this second blooming dependent on N fertilization rate in current year. A relatively high N rate is recommended to produce a second bloom.


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