Effects Of Light Quality Research Articles

Effect of Far-Red Light on Biomass Accumulation, Plant Morphology, and Phytonutrient Composition of Ruby Streaks Mustard at Microgreen, Baby Leaf, and Flowering Stages.

Far-red (FR) light influences plant development significantly through shade avoidance response and photosynthetic modulation, but there is limited knowledge on how FR treatments influence the growth and nutrition of vegetables at different maturity stages in controlled environment agriculture (CEA). Here, we comprehensively investigated the impacts of FR on the yield, morphology, and phytonutrients of ruby streaks mustard (RS) at microgreen, baby leaf, and flowering stages. Treatments including white control, white with supplementary FR, white followed by singularly applied FR, and enhanced white (WE) matching the extended daily light integral (eDLI) of FR were designed for separating the effects of light intensity and quality. Results showed that singular and supplemental FR affected plant development and nutrition similarly throughout the growth cycle, with light intensity and quality playing varying roles at different stages. Specifically, FR did not affect the fresh and dry weight of microgreens but increased those values for baby leaves, although not as effectively as WE. Meanwhile, FR caused significant morphological change and accelerated the development of leaves, flowers, and seedpods more dramatically than WE. With regard to phytonutrients, light treatments affected the metabolomic profiles for baby leaves more dramatically than microgreens and flowers. FR decreased the glucosinolate and anthocyanin contents in microgreens and baby leaves, while WE increased the contents of those compounds in baby leaves. This study illustrates the complex impacts of FR on RS and provides valuable information for selecting optimal lighting conditions in CEA.

Effect of Light Quality on the Growth and Mechanical Property of Tomato Grafted Seedlings

Seedlin g quality is directly related to the success rate of automatic grafting. To select the suitable light quality for cultivating mechanically grafted tomato seedlings, the effects of different LED light qualities on the morphological parameters and mechanical properties of tomato seedlings were measured in an artificial light environment in a plant factory. Combination of red (R) and blue (B) LEDs as follows: R: B=100:0 (RLT), R: B=75:25(RBI), R: B=50:50(RBII), R: B=25:75(RBIII), R: B=0:100(BLT). The results showed that Red light is beneficial for the elongation of the hypocotyl of seedlings, Blue light is beneficial for the accumulation of dry matter in seedlings and monochromatic red light can reduce the seedling index. The effect of light quality on rootstocks and scions is different. Increasing the proportion of blue light is beneficial for increasing the stem diameter of scions, but it is not significant for the stem diameter of rootstocks. On the 25th to 30th day, the growth rate of stem diameter is the fastest. Based on morphological characteristics, the suitable light quality for rootstocks is RBI and RBII, and scions are RBII and RBIII. The mechanical properties of rootstocks and scions under different light-quality treatments were measured, and the results showed that the mechanical properties of scions were generally better than those of rootstocks. The rootstock has a significantly better bending strength than the scion, while the scion has a significantly better radial and axial compression force than the rootstock. Considering the automatic grafting process and mechanical characteristics, BLT and RBII were selected as the suitable light quality for rootstocks and scions. Based on the influence of comprehensive light quality on morphological and mechanical characteristics, the suitable light quality for cultivating mechanically grafted tomato seedlings is RBII.

Alteration of growth, phenology, and yield of lily flowers through the synergetic effect of light spectra and endophytic bacterial priming

The production of ornamental flowers in controlled environment agriculture (CEA) has gained significant attention due to its potential for efficient cultivation. This study aimed to evaluate the influence of light quality (red, blue, red+blue, and white) after priming bulbs with Bacillus subtilis (Bs) on lily plant growth, phenology, yield, ornamental attributes, and pigmentation. Both light quality and Bs treatment significantly affected vegetative and generative organ development and overall plant growth. Bulbs primed with Bs and grown under blue light exhibited the earliest budding and flowering phases, along with an extended flowering period. The highest flower yield and productivity were achieved in Bs-primed bulbs under blue light. Regarding qualities, the best scores were obtained for Bs-primed bulbs grown under blue or red+blue light, compared to control plants grown under red light. The combined effects of Bs treatment and light quality also impacted photosynthetic pigment content in lily leaves. Throughout the growing season, the highest levels of photosynthetic pigments were detected under white light. Although the ratio between Chl a with other photosynthetic pigments were decreased during the flowering period, Bs treatment positively influenced those rations during the flowering phase when plants grown under monochromatic lights (red and blue). In summary, to achieve high-quality lily flowers in CEAs, the most promising approach involves utilizing a red+blue light spectrum in combination with Bs priming. This research highlights the importance of optimizing growing conditions and understanding the interplay between light quality and biological treatments for enhancing ornamental flower production in CEA systems.

Effect of Light Quality on Seed Potato (Solanum tuberose L.) Tuberization When Aeroponically Grown in a Controlled Greenhouse.

A plant factory equipped with artificial lights is a comparatively new concept when growing seed potatoes (Solanum tuberosum L.) for minituber production. The shortage of disease-free potato seed tubers is a key challenge to producing quality potatoes. Quality seed tuber production all year round in a controlled environment under an artificial light condition was the main purpose of this study. The present study was conducted in a plant factory to investigate the effects of distinct spectrum compositions of LEDs on potato tuberization when grown in an aeroponic system. The study was equipped with eight LED light combinations: L1 = red: blue: green (70 + 25 + 5), L2 = red: blue: green (70 + 20 + 10), L3 = red: blue: green (70 + 15 + 15), L4 = red: blue: green (70 + 10 + 20), L5 = red: blue: far-red (70 + 25 + 5), L6 = red: blue: far-red (70 + 20 + 10), L7 = red: blue: far-red (70 + 15 + 15), L8 = red: blue: far-red (70 + 10 + 20), and L9 = natural light with 300 µmol m-2 s-1 of irradiance, 16/8 h day/night, 65% relative humidity, while natural light was used as the control treatment. According to the findings, treatment L4 recorded a higher tuber number (31/plant), tuber size (>3 g); (9.26 ± 3.01), and GA3 content, along with better plant growth characteristics. Moreover, treatment L4 recorded a significantly increased trend in the stem diameter (11.08 ± 0.25), leaf number (25.32 ± 1.2), leaf width (19 ± 0.81), root length (49 ± 2.1), and stolon length (49.62 ± 2.05) compared to the control (L9). However, the L9 treatment showed the best performance in plant fresh weight (67.16 ± 4.06 g) and plant dry weight (4.46 ± 0.08 g). In addition, photosynthetic pigments (Chl a) (0.096 ± 0.00 mg g-1, 0.093 ± 0.00 mg g-1) were found to be the highest in the L1 and L2 treatments, respectively. However, Chl b and TCL recorded the best results in treatment L4. Finally, with consideration of the plant growth and tuber yield performance, treatment L4 was found to have the best spectral composition to grow quality seed potato tubers.

Light Quality Effect on Internal N Retranslocation in Podocarpus macrophyllus Precultured with Exponential Nutrient Loading.

Streetlamp light is inevitable in the night landscape of a city and may affect the phenology of newly planted ornamental plants, but it has rarely been fully examined. Newly transplanted ornamental plants probably suffer periodic shocks, which mainly result from the inefficient reuse of internal nutrients for new growth. Exponential nutrient loading (ENL) is well known for its ability to overcome transplant shocks by promoting retranslocation for the reuse of strengthened nutrients from internal reserves in precultured seedlings. Transplantation to urbanized lands is distinct from that of montane areas; this is mainly due to a high frequency of exposure to the artificial illumination of night lighting. It is suspected that this lighting modifies vegetative phenology and generates potential risks by increasing reliance on internal nutrient retranslocation. In this study, Podocarpus macrophyllus seedlings were cultured with ENL at low and high rates of nitrogen (N) deliveries (40 and 120 mg N seedling-1, respectively), and the high-rate treatment was identified as being able to trap seedlings within toxic states. A labeled 15N isotope was pulsed to transplanted seedlings exposed to simulated light qualities in red, green, and blue light spectra. The seedlings harvested at one month showed rare responses to the interactive spectra and preculture treatments, but most of them responded to the low-rate N preculture treatment with stronger abilities in terms of the reuse of internal N and the synthesizing of photosynthetic pigments. In conclusion, it was verified that night light enforces the effect on newly transplanted plants; the red light invoked internal N for reuse, and the blue light promoted the uptake of the current N. The internal N reserve established through preculture ENL rarely made a contribution to the night light effect, except for the enhancement of height growth in the red light. The red light spectrum was recommended for the exposure of newly transplanted seedlings due to its effect on the enhancement of the retranslocation of internal N and the induction of a steady state of uptake from the current N input.

Effects of light qualities on growth and physiological-biochemical traits of Scutellaria baicalensis.

Canopy spectral composition significantly affects growth and functional traits of understory plants. In this study, we explored the optimal light condition suitable for enhancing Scutellaria baicalensis's yield and quality, aiming to provide scientific reference for the exploitation and utilization of medicinal plant resources in the understory of forests. We measured the responses of growth, morphology, biomass allocation, physiological traits, and secon-dary metabolites of S. baicalensis to different light qualities. S. baicalensis was cultured under five LED-light treatments including full spectrum light (control), ultraviolet-A (UV-A) radiation, blue, green, and red light. Results showed that UV-A significantly reduced plant height, base diameter, leaf thickness, leaf area ratio, and biomass of each organ. Red light significantly reduced base diameter, biomass, effective quantum yield of photosystem Ⅱ (ФPSⅡ), and total flavonoid concentration. Under blue light, root length and total biomass of S. baicalensis significantly increased by 48.0% and 10.8%, respectively, while leaf number and chlorophyll content significantly decreased by 20.0% and 31.6%, respectively. The other physiological and biochemical traits were consistent with their responses in control. Our results suggested that blue light promoted photosynthesis, biomass accumulation, and secondary metabolite synthesis of S. baicalensis, while red light and UV-A radiation negatively affected physiological and biochemical metabolic processes. Therefore, the ratio of blue light could be appropriately increased to improve the yield and quality of S. baicalensis.

Genome-wide identification of GATA transcription factor family and the effect of different light quality on the accumulation of terpenoid indole alkaloids in Uncaria rhynchophylla.

Uncaria rhynchophylla is an evergreen vine plant, belonging to the Rubiaceae family, that is rich in terpenoid indole alkaloids (TIAs) that have therapeutic effects on hypertension and Alzheimer's disease. GATA transcription factors (TF) are a class of transcription regulators that participate in the light response regulation, chlorophyll synthesis, and metabolism, with the capability to bind to GATA cis-acting elements in the promoter region of target genes. Currently the charactertics of GATA TFs in U. rhynchophylla and how different light qualities affect the expression of GATA and key enzyme genes, thereby affecting the changes in U. rhynchophylla alkaloids have not been investigated. In this study, 25 UrGATA genes belonging to four subgroups were identified based on genome-wide analysis. Intraspecific collinearity analysis revealed that only segmental duplications were identified among the UrGATA gene family. Collinearity analysis of GATA genes between U. rhynchophylla and four representative plant species, Arabidopsis thaliana, Oryza sativa, Coffea Canephora, and Catharanthus roseus was also performed. U. rhynchophylla seedlings grown in either red lights or under reduced light intensity had altered TIAs content after 21 days. Gene expression analysis reveal a complex pattern of expression from the 25 UrGATA genes as well as a number of key TIA enzyme genes. UrGATA7 and UrGATA8 were found to have similar expression profiles to key enzyme TIA genes in response to altered light treatments, implying that they may be involved in the regulation TIA content. In this research, we comprehensively analyzed the UrGATA TFs, and offered insight into the involvement of UrGATA TFs from U. rhynchophylla in TIAs biosynthesis.

Minimizing Escherichia coli O157:H7 contamination in indoor farming: effects of cultivar type and ultra-violet light quality.

Bacterial contamination of produce is a concern in indoor farming due to close plant spacing, recycling irrigation, warm temperatures, and high relative humidity during production. Cultivars that inherently resist contamination and photo-sanitization using ultraviolet (UV) radiation during the production phase can reduce bacterial contamination. However, there is limited information to support their use in indoor farming. Lettuce (Lactuca sativa) cultivars with varying plant architectures grown in a custom-built indoor farm exhibited differences in E. coli O157:H7 survival after inoculation. The survival of E. coli O157:H7 was lowest in the leaf cultivar (open architecture) and highest in the romaine and oakleaf cultivars (compact architecture). Of the different UV wavelengths that were tested (UV-A, UV-A + B, UV-A + C), UV A + C at an intensity of 54.5 μmol m-2 s-1 (with 3.5 μmol m-2 s-1 of UV-C), provided for 15 min every day, was found to be most efficacious in reducing the E. coli O157:H7 survival on romaine lettuce with no negative effects on plant growth and quality. Contamination of E. coli O157:H7 on lettuce plants can be reduced and the food safety levels in indoor farms can be increased by selecting cultivars with an open leaf architecture coupled with photo-sanitization using low and frequent exposure to UV A + C radiation. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Effect of Red and Blue Light on the Growth and Antioxidant Activity of Alfalfa Sprouts

Alfalfa sprouts are popular as a gourmet vegetable that contains a variety of antioxidants with anti-cancer and anti-coronary heart disease properties. In this study, under a photosynthetic photon flux density (PPFD) of 30 mol·L−1 photoperiod of 12 h for 3 days, and a temperature of 25 ± 2 °C, we investigated the effects of different light qualities on the growth, nutritional quality and antioxidant activity of alfalfa sprouts by modulating LEDs with different red and blue ratios, and searched for suitable light-quality conditions for alfalfa sprout growth. The experimental results showed that the dark treatment favored the growth of alfalfa sprout hypocotyls and the increase of soluble sugar content; alfalfa fresh weight was the largest under the white and red light treatments; nitrate content was the lowest in the treatment with a red-to-blue ratio of 2:2 (2R2B); soluble proteins and total phenolic content were the highest in the treatment with red-to-blue ratio of 1:3 (1R3B); and the total antioxidant activity of sprouts was the highest in the blue light treatment.

Investigating the Effects of Full-Spectrum LED Lighting on Strawberry Traits Using Correlation Analysis and Time-Series Prediction.

In crop cultivation, particularly in controlled environmental agriculture, light quality is one of the most critical factors affecting crop growth and harvest. Many scholars have studied the effects of light quality on strawberry traits, but they have used relatively simple light components and considered only a small number of light qualities and traits in each experiment, and the results were not complete or objective. In order to comprehensively investigate the effects of different light qualities from 350 nm to 1000 nm on strawberry traits to better predict the future growth trend of strawberries under different light qualities, we proposed a new approach. We introduced Spearman's rank correlation coefficient to handle complex light quality variations and multiple traits, preprocessed the cultivation data through the CEEDMAN method, and predicted them using the Informer network. We took 500 strawberry plants as samples and cultivated them in 72 groups of dynamically changing light qualities. Then, we recorded the growth changes and formed training and testing sets. Finally, we discussed the correlation between light quality and plant trait changes in consistency with current studies, and the proposed prediction model achieved the best performance in the prediction task of nine plant traits compared with the comparison models. Thus, the validity of the proposed method and model was demonstrated.

Comparative Proteomic Analysis Reveals Candidate Pathways Related to the Effect of Different Light Qualities on the Development of Mycelium and Fruiting Body of Pleurotus ostreatus.

Light affects the morphology and physiology of Pleurotus ostreatus. However, the underlying molecular mechanism of this effect remains unclear. In this study, a label-free comparative proteomic analysis was conducted to investigate the global protein expression profile of the mycelia and fruiting bodies of P. ostreatus PH11 growing under four different light quality treatments. Among all the 2234 P. ostreatus proteins, 1349 were quantifiable under all tested conditions. A total of 1100 differentially expressed proteins were identified by comparing the light group data with those of the darkness group. GO and KEGG enrichment analyses indicated that the oxidative phosphorylation, proteasome, and mRNA surveillance pathways were the most related pathways under the light condition. qRT-PCR verified that the expression of the white collar 1 protein was significantly enhanced under white light. Additionally, glutamine synthetase and aldehyde dehydrogenase played important roles during light exposure. This study provides valuable insight into the P. ostreatus light response mechanism, which will lay the foundation for improved cultivation.

Effects of light quality and intensity on phycobiliprotein productivity in two Leptolyngbya strains isolated from southern Bahia's Atlantic Forest.

Cyanobacterial phycocyanin and phycoerythrin are gaining commercial interest due to their nutrition and healthcare values. This research analyzed the biomass accumulation and pigment production of two strains of Leptolyngbya under different combinations of light colors and intensities. The results showed that while Leptolyngbya sp.4 B1 (B1) produced all phycobiliproteins, Leptolyngbya sp.5 F2 (F2) only had phycocyanin and allophycocyanin. Both the color of the light and its light intensity affect the biomass accumulation and phycoerythrin concentration in strain B1. Although white light at medium intensity (50 μmol m-2 s-1) causes greater biomass accumulation (1.66 ± 0.13 gDW L-1), low-intensity (25 μmol m-2 s-1) green light induces lower biomass accumulation with twice the pigment content (87.70 ± 2.46 mg gDW -1), culminating in 71% greater productivity. In contrast, for the F2 strain, light intensity positively influenced biomass and pigment accumulation, being observed 2.25 ± 0.10 gDW L-1 under white light at 100 μmol m-2 s-1 and higher phycocyanin concentration (138.38 ± 3.46 mg gDW -1) under red light at 100 μmol m-2 s-1. These findings provide insights into optimizing the growth conditions by altering the intensity and wavelength of light for future production of phycocyanin and phycoerythrin from local cyanobacteria.

Supplemental light quality affects optimal seeding density of microgreens

AbstractHigher seeding densities can negatively affect the yield of microgreens. We quantified the effects of supplemental light quality and seeding density on the yield of microgreens. Seeds of red beet (Beta vulgaris L. ssp. esculenta) were grown in a greenhouse and provided with a narrow‐spectrum (or “purple”) and broad‐spectrum (or “white”) supplemental lighting at nighttime. Purple spectrum contained 90% red, 0% green, 10% blue, and 0% far‐red (R90: G0: B10: FR0) light, and white spectrum had 35% red, 42% green, 23% blue, and 0% far‐red light (R35: G42: B23: FR0). Each light quality treatment contained seeding densities of 50, 150, 300, and 450 g m−2. We measured fresh weight (FW) and dry weight (DW) on days 8, 10, 12, and 14 after sowing, relative growth rate (RGR), canopy area (CA), and chlorophyll (chl)a, chlb, betacyanin, and betaxanthin pigments. The optimal seeding density in the white treatment was 300 g m−2, whereas FW increased even at the seeding density of 450 g·m−2 in the purple treatment. The RGR of seedlings decreased with increasing seeding density but was higher by 27.8% in the purple than white treatment. The slope of the relationship between DW and CA (related to photosynthetic efficiency) was higher for the purple than white treatment (0.012 vs. 0.008 g cm−2). The ratio of chla to chlb (related to photosynthetic reaction center activity) increased by 15% in the purple than white treatment. Therefore, higher optimal density in the purple than white light quality treatment is likely due to increased photosynthetic efficiency of seedlings.

Substituting green light for partial red light promoted the growth and quality, and regulated the nitrogen metabolism of Medicago sativa grown under red-blue LEDs

Light quality can affect the growth of plants, regulate the accumulation and metabolism of substances, thereby improving the growth and quality of plants. Alfalfa is a vital forage with wide distribution and high value for feeding. However, few studies have investigated the effects of light quality on growth, quality, and nitrogen (N) metabolism regulation of alfalfa under artificial light control environment. In this study, the light intensity was 400 μmol·m−2·s−1 and photoperiods was 16/8 h. Five light quality treatments were used for alfalfa production, red-blue ratio of 3:1, 4:1 and 5:1, respectively, and on the basis of red-blue ratio of 4:1, 5% and 10% red light were replaced by green light were also used (R3B1, R4B1, R5B1, R19B5G1 and R18B5G2). The results showed that although the stomatal conductance and lysine content of the R3B1 treatment were significantly higher than other treatments, but the leaf area, fresh yield, contents of soluble sugar, sucrose, nitrate and ammonium, as well as the enzyme activities of NR, NiR, GOGAT and GS were the lowest among all treatments. The R3B1 treatment resulted in growth inhibition and reduced N metabolism levels. Strikingly, compared with the R4B1 treatment, the synthesis of Chl a+b, Chl a, Chl b, and free amino acid, as well as the accumulation of nitrate and crude protein, and the activity of GS also increased significantly in the two treatments which green light replaced partial of red light. However, the contents of soluble sugar, glutamate and lysine, as well as the activities of GOGAT and GDH, were significantly reduced in the R19B5G1 and R18B5G2 treatments. The carotenoids and sucrose contents of R19B5G1 treatment were significantly higher than R4B1 treatment, and the fresh weight and NR activity of R18B5G2 were significantly higher than R4B1 treatment. In addition, the content of starch and soluble protein and AK activity were not affected by light quality. In general, green light instead of partial red light increased the content of photosynthetic pigment and promoted the growth of alfalfa. Although the levels of glutamate, cysteine and lysine were reduced, it was beneficial to the accumulation of nitrate, free amino acid and crude protein, maintained the stability of N metabolism and improved the feeding value. These findings provide valuable insight into the effects of light quality regulation on value of feeding and N metabolism of alfalfa.

Effects of visible light wavelength on development and demographic parameters of Phytoseiulus persimilis (Acari: Phytoseiidae)

Environmental factors, such as the wavelength of light, can have a crucial impact on mite development. Little is, however, known about the effect of visible light quality on demographic parameters of Phytoseiidae. We therefore conducted series of laboratory experiments in which development and reproduction of Phytoseiulus persimilis Athias-Henriot feeding on Tetranychus urticae Koch eggs was investigated under various light conditions (white, blue, green, yellow, and red light). The results revealed that different light wavelengths influenced each developmental stage, with the green light conditions promoting longest pre-adult development. The longevity of both male and female mites varied significantly across light wavelengths, with the shortest lifespan observed under red light. The highest mean total fecundity, 16 eggs per female, was observed under white light conditions. Population parameters (R0, r, and λ) were also highest under white light and decreased with increasing light wavelength. These findings suggest that light wavelength plays a significant role in development, survival, and reproduction of the predatory mite, with white light being identified as providing the best light conditions for commercial production of P. persimilis.

Organogenesis and Antioxidant Capacity of Streptocarpus ×hybridus In Vitro under Different LED Light Spectrum Composition

Plants, whilst also having an ornamental role, are also a source of beneficial, bioactive compounds, and in vitro cultures are helpful in finding and obtaining them. Streptocarpus ×hybridus can be a source of antioxidants. The effect of different LED light qualities on the growth, development and metabolite composition of Streptocarpus multiplied in vitro on Murashige and Skoog medium was investigated. The used spectra were: 100% blue (B), 100% red (R), red and blue in 7:3 proportion (RB), 50% RB + 50% ultra violet (RBUV), 50% RB + 50% green (RBG), 50% RB + 50% yellow (RBY), 50% RB + 50% far red (RBfR), and white (WLed). A fluorescent lamp served as the control (Fl). For the best morphological quality of multiplied plants, the use of RBY light is recommended. Fl light reduced the antioxidant properties of extracts compared to LEDs. The most recommended spectrum in this aspect is RBfR, WLed, RBG and R light. These lights (except for R) stimulated the polyphenol content. RBY and R light influenced the highest content of free amino acids and reducing sugars. Studies showed that a selected LED light spectrum can influence the production of plant biomolecules with antioxidant properties and, compared to Fl light, improves the growth and development of multiplied plants.

Effects of light quality on microalgae cultivation: bibliometric analysis, mini-review, and regulation approaches.

The ever-increasing concern for energy shortages and greenhouse effect has triggered the development of sustainable green technologies. Microalgae have received more attention due to the characteristics of biofuel production and CO2 fixation. From the perspective of autotrophic growth, the optimization of light quality has the potential to promote biomass production and bio-component accumulation in microalgae at low cost. In this study, bibliometric analysis was used to describe the basic features, identify the hotspots, and predict future trends of the research related to the light quality on microalgae cultivation. In addition, a mini-review referring to regulation methods of light quality was provided to optimize the framework of research. Results demonstrated that China has the greatest interest in this area. The destination of most research was to obtain biofuels and high-value-added products. Both blue and red lights were identified as the crucial spectrums for microalgae cultivation. However, sunlight is the most affordable light resource, which could not be fully utilized by microalgae through the photosynthetic process. Hence, some regulation approaches (e.g., dyes, plasmonic scattering, and carbon-based quantum dots) are proposed to increase the proportion of beneficial spectrum for enhancement of photosynthetic efficiency. In summary, this review introduces state-of-the-art research and provides theoretical guidance for light quality optimization in microalgae cultivation to obtain more benefits.

In situ neutral desorption-extractive electrospray ionization mass spectrometry reveals red-blue light promoted the accumulation of amino acids and polyphenols in Anoectochilus roxburghii

Light quality affects plant leaf growth and its metabolism of amino acids and polyphenols. Anoectochilus roxburghii has been used for food, medicine, and ornamental purposes. To obtain the optimal light quality for improved accumulation of metabolites in A. roxburghii in vitro. The seedings were cultured under the white light (W), blue light (B), red light (R), red: blue light = 1:2 (R1B2), red: blue light = 1:1 (R1B1), red: blue light = 2:1 (R2B1). Twenty compounds in raw leaves were in situ rapidly identified within 20 s by neutral desorption-extractive electrospray ionization mass spectrometry (ND-EESI-MS) without any sample pretreatment, including eight amino acids, eleven polyphenols, and kinsenoside. Meanwhile, leaf area and the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) were evaluated. Our results showed that leaf area and antioxidant enzyme activities of the R2B1 were significantly higher than B or R group. The red-blue light increased the content of isoleucine, histidine, serine, arginine, and promoted the accumulation of caffeic acid, ferulic acid, quercetin, myricetin, kaempferol, and rutin in phenylpropane metabolism, especially in the R2B1, which could be used as the optimal light quality. ND-EESI-MS could enhance our understanding of the effect of light quality on the accumulation of amino acids and polyphenols in A. roxburghii.

Effects of light quality and intensity on the juvenile physiological metabolism of Babylonia areolata

Babylonia areolata lives in bottom sediments during the day and emerges at night to forage. This study examined how different light qualities (blue, white, green, and red light) and intensities (0 and 2–32 μmol·m s−1) influence the growth and physiological activity of B. areolate juveniles. Changes in the activity of digestive enzymes, such as pepsin (PPS), lipase (LPS), and amylase (AMS), as well as energy metabolic enzymes, such as hexokinase (HK), pyruvate kinase (PK), lactic dehydrogenase (LDH) and succinic dehydrogenase (SDH), were also studied. The result showed that juveniles exhibited substantial variations under different light conditions. Specifically, the maximum bodyweight specific growth rates (SGR) under green, blue, red, and white light conditions were 3.56 ± 0.45 %·d−1, 3.03 ± 0.68 %·d−1, 3.01 ± 0.72 %·d−1 and 2.99 ± 0.73 %·d−1 at light intensities of 2 μmol·m−2·s−1, 4 μmol·m−2·s−1, 8 μmol·m−2·s−1 and 2 μmol·m−2·s−1, respectively. The shell length SGR, shell width SGR and body weight SGR in the dark group were not statistically different from those in the red light group at 2 μmol·m−2·s−1 (p > 0.05), while the body weight SGR of the dark group was significantly lower than that in other groups (p < 0.05). At the light intensity of 2 μmol·m−2·s−1, the activity of PPS in green and blue light was significantly higher than in red light (p < 0.05). The activity of HK in green light was considerably higher than that in darkness (p < 0.05), and there was no significant difference in the activity of LDH between the dark group and the red light group (p > 0.05), although the results of both groups were significantly higher than those of the blue and white light (p < 0.05). In addition, the activity of PPS, AMS, HK, PK, and LDH was considerably higher in darkness than in other light qualities (p < 0.05). Under different light qualities, the activity of all enzymes at the low light intensity was significantly higher than that at the high light intensity (p < 0.05), which coincided with growth characteristics. Therefore, blue and green light promoted the growth of juveniles at low light intensity (2 μmol·m−2·s−1), but darkness inhibited their growth. The findings of this study could be used as a foundation for optimizing lighting conditions and figuring out the optimum conditions for the growth and survival of B. areolata. Furthermore, this study could help explain how to control lighting conditions in real-world breeding situations.

Effect of Light Quality on Petal Coloring in Potted Miniature Roses

Effect of Light Quality on Petal Coloring in Potted Miniature Roses