Red LED Light Research Articles

Differential regulation of red light- and ethephon-induced degreening in postharvest kumquat fruit

Peel color is closely associated with the commercial value of citrus fruit. In early market or tropical regions, citrus fruit often show non-uniform coloration, which requires degreening practice at post-harvest stage. Here, we studied the degreening effect of red LED light, ethephon, and their combination treatment on kumquat fruit. Both red LED light and ethephon promoted fruit degreening, causing ultrastructural changes of chloroplasts accompanied by chlorophyll degradation. Transcriptome analysis revealed metabolic reprogramming in chloroplasts but the way how genes responded to red LED light and ethephon were remarkably different. Transient expression in Nicotiana benthamiana suggested that FcrCLH, FcrPPH and FcrSGR genes were potentially key factors in regulation of fruit degreening. Furthermore, red LED light promoted the catabolism of chloroplast components in vitro. This study provides novel insights into the molecular mechanism of fruit degreening and unravels an efficient practice for future post-harvest management of citrus fruit.

3D error calibration of spatial spots based on dual position-sensitive detectors.

In this paper, a dual position-sensitive detector-based vision measurement system camera is built instead of a traditional CCD camera. The 3D position information for the light point is calculated according to the 2D coordinate information of a certain light point in the space illuminated on the two position-sensitive detector (PSD) photosensitive surfaces, which is used for position detection of the spatial light point. In addition, the positioning model for 2D PSDs with different spot sizes in the Gaussian spot mode is derived by the mathematical model of Lucovsky's differential equation for a PSD. For the nonlinear distortion of the PSD, a nonlinear error calibration method using a particle swarm combined with a back propagation neural network is proposed to correct the errors in the measured values through the relationship between the input and output values, to obtain the predicted value that approximates the real coordinates. Then, by comparing the influence of different spot sizes on the positioning accuracy, we conclude that the smaller the spot formed by the convergence of the beam under the optical lens, the higher the positioning accuracy. We believe this conclusion can help improve the accuracy of PSD measurements. Finally, a red LED light spot is set up, and the 3D position measurement and error calibration of the light spot is done by dual PSD cameras, which better solves the position detection problem of a space light spot under close-range conditions because it is fast, reliable, and easy to implement. It also provides an effective method to detect the motion trajectory of a moving light spot in space.

Red LED light therapy associated with epidermal growth factor on wound repair process in rats.

Epidermal growth factor (EGF) and light-emitting diode (LED) are currently deployed as promissory treatments for skin repair; however, the mechanisms of their association are not yet evidenced. Thus, the present study aimed to evaluate the effects of combined treatment with EGF and red LED on the wound healing processes in rats. Adult Wistar rats were randomized in control group (CG) wounds without treatment; wounds submitted to EGF treatment (EGF); wounds submitted to LED treatment (LED); wounds submitted to EGF associated with LED treatments (EGF/LED). Treatments were performed immediately after the surgical procedure and each 24h, totaling 8 sessions. Moreover, LED was applied before EGF treatment at a single point in the center of the wound. Morphological characteristics and the immunoexpression of COX-2, VEGF, and TGF-β were measured. The results demonstrated that EGF/LED group presented a higher wound healing index. Additionally, all experimental groups presented similar findings in the histological evaluation, the degree of inflammation, and the area of dermis-like tissue. However, for EGF-treated animals (with or without LED), neoepithelial length was higher. Furthermore, all the treated groups decreased COX-2 and increased VEGF immunoexpression, and only EGF/LED group enhanced the TGF-β protein expression when compared to the untreated group. This research shows that EGF and LED modulate inflammatory process and increase the vascularity. In addition, treatment of EGF associated with LED promoted a more evident positive effect for increasing TGF-β expression and may be promising resources in the clinical treatment of cutaneous wounds.

Supplemental red LED light promotes plant productivity, “photomodulates” fruit quality and increases Botrytis cinerea tolerance in strawberry

This work provides new evidences on the effect of pre-harvest red (R), green (G), blue (B), and white (W – R:G:B; 1:1:1) LED light supplementation on production, nutraceutical quality and Botrytis cinerea control of harvested strawberry fruit. Yield, fruit color, firmness, soluble solid content, titratable acidity, primary and specialized metabolites, expression of targeted genes and mold development were analyzed in fruit from light-supplemented plants, starting from the strawberry flowering, radiating 250 μmol m–2 s–1 of light for five hours per day (from 11:00 to 16:00 h), until the fruit harvest. Briefly, R light induced the highest productivity and targeted anthocyanin accumulation, whilst B and G lights increased the accumulation of primary and secondary metabolites especially belonging to ellagitannin and proanthocyanidin classes. R light also promoted pathogen tolerance in fruit by the upregulation of genes involved in cell wall development (F × aPE41), inhibition of fungus polygalacturonases (F × aPGIP1) and the degradation of B. cinerea beta-glucans (F × aBG2-1). Our dataset highlights the possibility to use red LED light to increase fruit yield, “photomodulate” strawberry fruit quality and increase B. cinerea tolerance. These results can be useful in terms of future reduction of agrochemical inputs through the use of R light, enhancing, at the same time, fruit production and quality. Finally, further analyses might clarify the effect of pre-harvest supplemental G light on postharvest fruit quality.

Farklı LED ışıklar altında yetiştirilen köksüz su mercimeğinin (Wolffia arrhiza) Dumas yöntemi kullanılarak ham protein içeriğinin belirlenmesi

Rootless duckweed (Wolffia spp.) has the potential high-protein food source for humans. Wolffia is a member of the Lemnaceae family and is the world's smallest spermatophyte, with reduced roots, stems, and leaves. Scientific research on Wolffia species is relatively new, and this species is believed to be rare in Turkey. The phytochemicals and nutritional composition of plants are significantly affected by environmental factors in the natural or cultivated medium. In this study, Wolffia arrhiza was collected and cultured from a local area in Yeşilırmak Delta (Samsun) grown under controlled conditions using different LED lights. The Dumas method was used to determine the amount of crude protein. The protein content, calculated by multiplying the nitrogen (%) content by the standard conversion factor 6.25, was also evaluated by using different conversion factors in the literature. The results showed that rootless duckweed can be successfully grown under artificial lighting conditions with different light spectrums. The protein content of rootless duckweed, which was around 10% in the natural environment, increased considerably under red LED light (41.6% protein). The effect of different lights on protein content of W. arrhiza was observed as red LED > blue LED > purple LED > fluorescent. With its high protein content, environmentally friendly and sustainable production, Wolffia has the potential to quickly take place in the plant-based protein and functional food market as an alternative to traditional crops in the near future.

Far-red BODIPY-based oxime esters: photo-uncaging and drug delivery.

Far-red BODIPY-based oxime esters for photo-uncaging were designed to release molecules of interest with carboxylic acids. The low power red LED light breaks the N-O oxime ester bond and frees the caged molecules. We studied the mechanism and kinetics of the uncaging procedure using a 1H NMR spectrometer. Moreover, the drug delivery strategy to release valproic acid (VPA) on demand was tested in vitro using this far-red BODIPY photo-uncaging strategy to induce apoptosis in tumor cells.

Colored LED Lights: Use One Color Alone or with Others for Growth in Hedyotis corymbosa In Vitro?

In recent years, light-emitting diode (LED) technology has been applied to improve crop production and induce targeted biochemical or physiological responses in plants. This study investigated the effect of different ratios of blue 450 nm and red 660 nm LEDs on the overall plant growth, photosynthetic characteristics, and total triterpenoid production in the leaves of Hedyotis corymbosa in vitro plants. The results showed that a high proportion of blue LED lights had a positive effect on enhancing photosynthesis and the overall biomass. In addition, blue LED lights were shown to be more effective in controlling the production of the total triterpenoid content compared with the red LED lights. Moreover, it was also found that plants grown under a high proportion of red LEDs exhibited reduced photosynthetic properties and even induced damage to the photosynthetic apparatus, which indicated that the blue or red LED lights played contrary roles in Hedyotis corymbosa.

Dry mass input into fruits can be predicted by fine root morphology of pepper cultivars exposed to varied lighting spectra

Many pepper cultivars can be raised under artificial lighting in a plant factory. An easily measured parameter is needed to fast predict fruit loading in pepper cultivars. In this study, four pepper cultivars with contrasting manners in growth and fruiting were cultured under three light-emitting diode (LED) spectra in comparison with a sunlight control. It was found that the red-light spectrum (71.7% red-, 13.7% green-, 14.6% blue-lights) increased over 40% of dry mass in fruits, while the green-light spectrum (26.2% red-, 56.4% green-, 17.4% blue-lights) induced no fruiting compared to the control. Only two cultivars responded by fine root morphology, which was characterized as smaller surface-area and fewer tip-number in the blue-light spectrum (7.8% red-, 33.7% green-, 48.5% blue-lights) than in red LED light. Tip-number showed a negative correlation with fruit dry-mass in three cultivars, while fine root diameter increased with dry mass in fruits. In conclusion, fine root tip-number can be used as a predictor of fruit dry-mass in pepper cultivars high in fruit quality or yield. The red-colour light was recommended for raising pepper cultivars in a plant factory with the purpose of greater fruit productivity.

Bioactive extracts and association with C and N in Eleutherococcus senticosus subjected to chitosan nanoparticles in contrasting light spectra.

Bioactive compounds are major reasons for the value of Eleutherococcus senticosus, which can be modified by different lighting spectra. Light-emitting diode (LED) provides lights with specific spectra which can interact with other treatments to impact plant bioactive production. Chitosan nanoparticle (CN) is a biopolymer derived from marine creatures. It's usage may be a practical approach to cope with uncertainties in secondary metabolites induced by illumination. Carbon (C) and nitrogen (N) cyclings link plant eco-physiological performance and bioactive substance; hence their associations may reveal the mechanism of joint light-CN interaction. In this study, E. senticosus seedlings were raised under artificial lighting spectra from high-pressure sodium (HPS) lamps (44% red, 55% green, 1% blue) and white (44% red, 47% green, 8% blue) and red colored (73% red, 13% green, 14% blue) LED panels. Half of the seedlings received CN and the other half received distilled water as the control. Compared to the HPS spectrum, the red-light induced stronger shoot growth with greater biomass accumulation and higher water uptake but resulted in lower N concentration and biomass ratio in the root. The white light caused more biomass allocated to the root and strengthened stem C concentration. Stem eleutheroside B increased with shoot growth, while root eleutheroside B had a positive association with leaf C and stem protocatechuic acid had a negative association with leaf N. Having the CN treatment in white and red LED lights is recommended for increasing accumulation of bioactive compounds in the shoots and roots of E. senticosus seedlings, respectively.

Effect of Different Light Qualities and Intensities on the Yield and Quality of Facility-Grown Pleurotus eryngii.

Proper light is essential for the formation and development of macrofungi fruiting bodies. Currently, there are unclear treatment conditions, such as light quality and light intensity, in the production of Pleurotus eryngii in intensive cultivation facilities, which is not helpful to the formation and implementation of standardized production programs. The research discussed in this paper investigated the effects of different light quality and intensity conditions on the yield and quality of P. eryngii. The results showed that the yield and nutritional quality of the red light treatment samples were higher than those of the white light control, the commercial properties were good, and the energy consumption of the red LED light source was the lowest under the same light intensity. The results of this experiment further provide a reference for the energy-saving and high-quality cultivation of P. eryngii.

Aggregation-Induced Emission Poly(meth)acrylates for Photopatterning via Wavelength-Dependent Visible-Light-Regulated Controlled Radical Polymerization in Batch and Flow Conditions.

A robust wavelength-dependent visible-light-regulated reversible-deactivation radical polymerization protocol is first reported for the batch preparation of >20 aggregation-induced emission (AIE)-active polyacrylates and polymethacrylates. The resulting polymers possess narrow molar mass distributions (Đ ≈ 1.09-1.25) and high end-group fidelity at high monomer conversions (mostly >95%). This demonstrated control provides facile access to the in situ generation of complex sequence-defined tetrablock copolymers in one reactor, even while chain extending from less reactive monomers. Polymerizations can be successfully carried out under various irradiation conditions, including using UV, blue, green, and red LED light with more disperse polymers obtained at the longer, less energetic, wavelengths. We observe a red shift and wavelength dependence for the most efficient polymerization using LED illumination in a polymerization reaction. We find that the absorption of the copper(II) complex is not a reliable guide to reaction conditions. Moreover, the reported protocol is readily translated to a flow setup. The prepared AIE-active polymers are demonstrated to exhibit good photopatterning, making them promising materials for applications in advanced optoelectronic devices.

Influence of light quality and some growth regulators in inducing the production of Podophyllotoxin, a bioactive compound against cancer, in adventitious roots formed in the leaves of Hyptis suaveolens

Podophyllotoxin (PTOX) is an aryltetraline lignan used to treat skin lesions, such as warts, human papilloma virus, and genital infections. Hyptis suaveolens has PTOX in its roots and the culture of its plant tissues in vitro has been increasingly used to produce rare and high-quality medicinal compounds. Adventitious roots are an attractive source of phytochemicals due to their genetic and biosynthetic stability. Thus, the aim of the present study is to investigate adventitious roots’ induction in leaves and nodal segments under different light qualities and auxins in H. suaveolens. Adventitious roots have only emerged in H. suaveolens leaves grown in semi-solid MS medium, in the absence of light and under red light-emitting diode (LED). Root dry weight values recorded for these treatments were statistically equal to each other, i.e., 21.84 and 29.81 mg, respectively. PTOX quantification was performed in the dark (10.72 µg g−1) and under red LED (9.93 µg g−1). Indole-3-butyric acid (IBA) and naphthaleneacetic acid (NAA) (0.5, 1.0 and 2.0 mg L−1) concentrations induced adventitious roots’ formation in leaves of plants belonging to this species. Explant supplemented with 2.0 mg L−1 NAA led to higher root dry weight (45.53 mg) in leaves. However, the 1.0 mg L−1 IBA treatment produced more PTOX (9.96 µg g−1 root). Nodal segments of H. suaveolens, IBA and NAA concentrations (0.5, 1.0 and 2.0 mg L−1) also induced adventitious roots’ formation. The treatment with 0.5 mg L−1 IBA resulted in higher root dry weight (37.62 mg) in the nodal segment. However, 1 and 2 mg L−1 IBA resulted in lower root dry weight and higher PTOX (9.97 µg g−1 and 9.95 µg g−1). In conclusion, adventitious root formation and PTOX induction in H. suaveolens leaves grown in semi-solid MS medium only happen in plants grown in the dark and under monochromatic red LED light. Growth regulator NAA was the best element to induce adventitious roots’ emergence in leaves, whereas IBA was the best one for such a purpose in nodal segment. Growth regulator NAA can inhibit the synthesis of PTOX, but IBA induces this secondary compound.

Effects of selected light wavelengths on the transcript levels of photoreceptors and growth-related hormones and peptides in the Malabar grouper Epinephelus malabaricus

Fish growth is influenced by environmental cues, including light conditions. The duration of exposure (photoperiod), the intensity of exposure (illumination), and quality (light spectrum) play crucial roles in maximizing growth. This study aimed to clarify how selected light wavelengths are perceived and transduced as an internal signal to stimulate growth of the Malabar grouper Epinephelus malabaricus, an important aquaculture species in Asian countries. Four opsins (RH1, RH2, SWS2, and LWS) were selected from the database of photoreceptors of groupers, and reverse-transcription polymerase chain reaction revealed that these opsins were expressed in the eyes and brain. When fish were reared under conditions of long-day (light:dark = 14:10) with red (peak at 632 nm), green (519 nm), and blue (465 nm) LED and natural light, the specific growth rate was higher (P < 0.05) in fish exposed to blue LED light than to red LED light. Rearing fish under shorter light wavelengths (blue or green) resulted in high transcript levels (P < 0.05) of RH1 and RH2 in the eyes (retina) and of RH1 and SWS2 in the brain (diencephalon), suggesting that certain light wavelengths activate photoreceptors in light perceptive organs. The transcript levels of growth hormone (GH) and insulin-like growth factor (IGF-I) increased significantly (P < 0.05) in the pituitary and liver of fish reared under blue LED light, respectively. Moreover, similar increases (P < 0.05) in the transcripts of neuropeptide Y (NPY) and pro-opiomelanocortin were observed in the brain of fish reared under blue LED light. We concluded that blue light perceived by visual opsins in the eyes and brain activates the growth of the endocrine axis and its interaction with NPY. Consequently, rearing the Malabar grouper under specific light wavelengths helps maximize their growth.

Effect of Light Quality on Metabolomic, Ionomic, and Transcriptomic Profiles in Tomato Fruit.

Light quality affects plant growth and the functional component accumulation of fruits. However, there is little knowledge of the effects of light quality based on multiomics profiles. This study combined transcriptomic, ionomic, and metabolomic analyses to elucidate the effects of light quality on metabolism and gene expression in tomato fruit. Micro-Tom plants were grown under blue or red light-emitting diode light for 16 h daily after anthesis. White fluorescent light was used as a reference. The metabolite and element concentrations and the expression of genes markedly changed in response to blue and red light. Based on the metabolomic analysis, amino acid metabolism and secondary metabolite biosynthesis were active in blue light treatment. According to transcriptomic analysis, differentially expressed genes in blue and red light treatments were enriched in the pathways of secondary metabolite biosynthesis, carbon fixation, and glycine, serine, and threonine metabolism, supporting the results of the metabolomic analysis. Ionomic analysis indicated that the element levels in fruits were more susceptible to changes in light quality than in leaves. The concentration of some ions containing Fe in fruits increased under red light compared to under blue light. The altered expression level of genes encoding metal ion-binding proteins, metal tolerance proteins, and metal transporters in response to blue and red light in the transcriptomic analysis contributes to changes in the ionomic profiles of tomato fruit.

5-Aminolevulinic Acid and Red Led in Endodontics: A Narrative Review and Case Report.

The present study aims to discuss the main factors involving the use of 5-aminolevulinic acid together with red LED light and its application in endodontic treatment through a narrative review and a case report. Persistence of microorganisms remaining on chemical-mechanical preparation or intracanal dressing is reported as the leading cause of failure in endodontics. Photodynamic therapy has become a promising antimicrobial strategy as an aid to endodontic treatment. Being easy and quick to apply, it can be used both in a single session and in several sessions, as well as not allowing forms of microbial resistance. 5-aminolevulinic acid in combination with red LED light has recently been studied in many branches of medicine, with good results against numerous types of bacteria including Enterococuss faecalis. The case report showed how bacterial count of CFU decreased by half (210 CFU/mL), after 45 min of irrigation with a gel containing 5% of 5-aminolevulinic acid compared to the sample before irrigation (420 CFU/mL). The subsequent irradiation of red LED light for 7 min, the bacterial count was equal to 0. Thus, it is concluded that the use of 5-aminolevulinic acid together with red LED light is effective in endodontic treatment.

The effects of red LED light on pig sperm function rely upon mitochondrial electron chain activity rather than on a PKC-mediated mechanism.

While irradiation with red LED light has been reported to modulate sperm function in different mammalian species, the mechanisms underlying their response are poorly understood. This work sought to provide new insights into whether this effect relies on a direct action upon mitochondrial electron chain and/or on PKC-linked mechanisms such as those related to opsins. For this purpose, pig semen was light-stimulated for 1, 5 or 10 min in the presence/absence of antimycin A, an inhibitor of the mitochondrial electron chain, or PKC 20–28® (PKCi), a PKC inhibitor. Antimycin A completely blocked the effects of light at all the performed irradiation patterns. This effect was linked to a complete immobility of sperm, which was accompanied with a significant (p < 0.05) drop in several markers of mitochondrial activity, such as JC-1 staining and O2 consumption rate. Antimycin A, however, did not affect intracellular ATP levels, intramitochondrial calcium, total ROS, superoxides or cytochrome C oxidase (CCO) activity. In the case of PKCi, it did also counteract the effects of light on motility, O2 consumption rate and CCO activity, but not to the same extent than that observed for antimycin A. Finally, the effects observed when sperm were co-incubated with antimycin A and PKCi were similar to those observed with antimycin A alone. In conclusion, red LED light acts on sperm function via a direct effect on mitochondrial electron chain. Additionally, light-activated PKC pathways have a supplementary effect to that observed in the electron chain, thereby modulating sperm parameters such as motility and CCO activity.

Effect of a 5-aminolevulinic acid gel and 660 nm red LED light on human oral osteoblasts: a preliminary in vitro study

This study aimed to evaluate the effects of a new photodynamic protocol (ALAD-PDT) on primary human osteoblasts (hOBs). The ALAD-PDT protocol consists of a heat-sensitive gel with 5% 5-delta aminolevulinic acid commercialized as Aladent (ALAD), combined with 630 nm LED. For this purpose, the hOBs, explanted from human mandible bone fragments, were used and treated with different ALAD concentrations (10%, 50%, 100% v/v) incubated for 45 min and immediately afterwards irradiated with a 630 nm LED device for 7 min. The untreated and unirradiated cells were considered control (CTRL). The cellular accumulation of the photosensitizer protoporphyrin IX (PpIX), the proliferation, the alkaline phosphatase (ALP) activity, and the calcium deposition were assessed. All concentrations (10, 50, 100%) determined a significant increment of PpIX immediately after 45 min of incubation (0 h) with the highest peak by ALAD (100%). The consequent 7 min of light irradiation caused a slight decrease in PpIX. At 48 h and 72 h, any increment of PpIX was observed. The concentration 100% associated with LED significantly increased hOB proliferation at 48 h (+ 46.83%) and 72 h (+ 127.75%). The 50% and 100% concentrations in combination to the red light also stimulated the ALP activity, + 12.910% and + 14.014% respectively. The concentration 100% with and without LED was selected for the assessment of calcium deposition. After LED irradiation, a significant increase in calcium deposition was observed and quantified (+ 72.33%). In conclusion, the ALAD-PDT enhanced proliferation, the ALP activity, and mineralized deposition of human oral osteoblasts, highlighting a promising potential for bone tissue regeneration.

Counteracting Side-effects of Photodynamic Therapy for Actinic Keratoses.

Actinic keratoses (AKs) are precursors of squamous cell carcinomas and early intervention is important. Photodynamic therapy (PDT) is often first-choice treatment for widespread AKs. Classic PDT consists of: Superficial curettage, application of 5-aminolevulinic acid or methyl aminolevulinate, incubation and protoporphyrin IX (PpIX) accumulation under occlusion for 3 hours, followed by illumination with red light-emitting diode light (37 J/cm2). Classic PDT is effective in treating AKs, but side-effects include unpleasant pretreatment, severe pain during illumination, inflammation after treatment, and long waiting time in the clinic. This targeted mini review describes efforts to counteract side-effects and simplify the procedure considering the clinic capacity. Changes are only acceptable if treatment effect is maintained. We introduce the following procedure changes: (i) reducing pre-treatment pain, bleeding, and oozing by omitting curettage; (ii) long-term illumination for 2 hours during PpIX formation (already in use as daylight PDT) and shortening of incubation time from 3 hours to 30 minutes to minimize pain and inflammation risk. In addition, options of timing, incubation, and illumination indoors and outdoors are discussed, focusing on advantages and disadvantages for patients and clinics. We report several options to counteract side-effects of classic PDT.

Effects of blue and red LED lights on rubisco activase gene expression, CO2 fixation efficiency and plant morphology of Gerbera jamesonii

Light quality is known to affects numerous plants’ physiological and metabolic processes during development period, including photosynthesis and morphogenesis. Light properties such as light wavelength has been optimized for several cultivated crops. In this study, the effects of LED light wavelengths blue and red on both photosynthetic performance and morphology of Gerbera jamesonii plantlets was investigated. The results showed the photosynthesis efficiency via the photo-pigment system and mediated regulation of rubisco activase encoding gene (RCA) mechanism was significantly enhanced by blue light. The expression of RCA was approximatly 2.7 times higher than those under red light. In contrast, chlorophyll contents, CO2 assimilation, total carbohydrate and RCA expression was reduced under red wavelength. However, both single-wavelengths caused a dramatically negative impact on G. jamesonii. Total chlorophyll/carotenoid value or higher carotenoid contents was lower under blue light; fragile petioles and drawrfism morphology was occurred under red and blue LED, respectively. The combination of blue and red light in the lighting spectrum significantly improved the limitations of single-wavelength. The supplement of blue light under red light background (at blue LED and red LED ratio = 1:4) improved plant photosynthesis while maintained the normal morphology of plants, although the expression of RCA and net photosynthesis of plants in BR LED was lower than in the control. Our results obviously provide the scientific evidences for requirement of LED light in micropropagation or canopy culture of G. jamesonii.

Comparison of Some Behavioural Responses in Budgerigars (Melopsittacus undulatus) Raised in Cages Enriched with Coloured LED Lights.

Simple SummaryIn this study, the environment of hand-raised budgerigars in captivity (people’s homes) was simulated. We investigated the effect of coloured LED lights in addition to natural light on the behaviour of the birds. For birds raised by humans, the light in houses is significantly different from the lighting conditions in a bird’s natural habitat. This may lead to behavioural and health problems in birds, adversely affecting their wellbeing. This study investigated how white, blue, yellow, and red LED lights applied at the beginning of the dark cycle of the photoperiod affected the behaviours of budgerigars. The results indicated that when offered the opportunity, the birds chose yellow light. The open field tests (OFT I and II) were used to assess the locomotion and exploratory behaviour of birds. The results of the OFT I test, which was performed with an unfamiliar object, indicated that the group experiencing yellow light was more self-confident. The birds in cages with blue light felt more comfortable and displayed more social behaviour. People will be able to use this new information to improve the living conditions of their pet budgerigars.This study examined the effects of exposure to coloured LED lights on some behavioural responses, food and water consumption, and live weight in budgerigars kept in captivity using behavioural tests to compare different lighting conditions. Budgerigars’ feeding, comfort, social, fear, and resting behaviours and behavioural reactions to a new environment were studied. Twelve male birds were assigned to four groups, with three birds in each group. They were provided with food and water ad libitum in wire cages at 25 ± 2 °C in a room. The study was conducted with 10 h of natural light, 6 h of LED light (white, blue, yellow, and red LED lights), and 8 h of darkness. Their behaviours in the cages were observed. Home cage avoidance (HCA) and two open field tests (OFT) were performed. No difference was observed in the LW and food consumption, but the blue and yellow groups consumed less water. The blue group displayed more comfort and social behaviours. In the HCA test, the red group demonstrated higher reactions. Furthermore, the birds in the yellow group stayed closer to the centre of the platform in the OFT I test, and they chose the compartment simulating their familiar environment in the OFT II test. Consequently, it was concluded that first yellow and then blue lights may be used to prevent stress-related problems for these birds. Our findings could be used to improve the hand-rearing conditions of captive budgerigars.