Search Results (168)

This experiment aimed to investigate the effects of different lighting cycles on the growth performance, serum biochemical indices, slaughter performance, skeletal development, and meat quality of yellow-feathered broiler chickens. A total of 256 10-day-old Liangfenghua yellow-feathered male broilers were randomly assigned to four groups, each with 8 replicates, and each replicate contained 8 chickens. The four lighting cycles used were 18L:6D, 20L:4D, 22L:2D, and 23L:1D (hours of light:dark), and the chickens were fed until 63 days of age. The results indicate that with increasing light exposure duration, the average daily gain and live weight of yellow-feather broilers from 10 to 21 days of age (p = 0.07), the average daily feed intake from 42 to 63 days of age (p < 0.01), as well as the average daily feed intake, daily gain, and feed-to-gain ratio from 1 to 63 days of age (p < 0.05), all showed linear changes. The live weight, daily gain, and feed-to-gain ratio from 42 to 63 days of age exhibited both linear and quadratic variations (p < 0.01). The 22L:2D group achieved the highest live weight and daily gain at 63 days, with the lowest feed-to-gain ratio. Serum glucose levels displayed quadratic variation, while phosphorus levels showed both linear and quadratic changes; the 22L:2D group had the lowest serum glucose and the highest phosphorus levels. The semi-eviscerated rate and the bursa of Fabricius index varied linearly, whereas the leg muscle rate showed quadratic variation. The 20L:4D group had the highest total eviscerated rate, breast muscle rate, and leg muscle rate (p < 0.05), with the lowest Fabricius and thymus indices. The length, width, and volume of the femur and tibia, as well as the tibia bone volume and tissue volume, all changed linearly (p < 0.05). The tibia bone volume fraction exhibited both linear and quadratic changes, with the 18L:6D group showing the highest femur length, width, tibia bone volume, tissue volume, and bone volume fraction. Light exposure significantly affected meat pH, colour, shear force, drip loss, and cooking loss. The crude protein content in the breast muscle showed quadratic variation, while ash and cysteine contents displayed both linear and quadratic changes. The 22L:2D group had the highest crude protein content, pH at 24 h, shear force, and drip loss, but the lowest amino acid and ash contents (p < 0.05). Additionally, there were significant differences in the flavour of the breast muscle under different light cycles. In summary, the photoperiod significantly affects the production performance, skeletal development, meat quality, and flavor of yellow-feathered broilers. The 22L:2D photoperiod yielded the best outcomes in promoting growth, improving feed efficiency, and enhancing meat quality; however, it may adversely affect skeletal development and structural integrity, and caution should be exercised for long-term rearing. Full article

Oenothera biennis L. is an economically important oil and ornamental crop. However, the regulatory mechanisms underlying its flower bud differentiation remain poorly understood. To elucidate the interactions between the environmental cues and molecular networks governing this process, this study investigated natural populations from the Lesser Khingan Mountains. The results demonstrate that exposure to 0–10 °C for at least 15 d and long-day (LD) conditions correlated strongly with floral induction. Notably, 200 mg·L⁻¹ of exogenous GA₃ effectively substituted for vernalization, significantly promoting bolting and advancing flower development. Expression profiling revealed an antagonistic expression pattern between floral activators such as ObFT and ObAP2 and repressors such as ObFLC. Both vernalization and GA₃ upregulated floral activators while suppressing the repressors, and these processes were coincident with the transition to flowering. Flower bud differentiation goes through six continuous stages, spanning from inflorescence primordia to gynoecium primordia formation. Hybrid fruit setting, the pollen–ovule ratio (98) and the outcrossing index (OCI = 3) confirmed that O. biennisis is a facultative selfer, with reproduction predominantly relying on self-pollination. This study provides a systematic characterization of the integrated regulatory network coordinating vernalization, photoperiod, and gibberellin in Oenothera flowering, proposing a framework for the putative FT-FLC antagonism. These findings establish a molecular foundation for the precision management of flowering time and informed breeding strategies. Full article

CONSTANS-LIKE (COL) genes are pivotal regulatory components in the photoperiodic flowering pathway of plants. These genes can be regulated by both photoreceptors and the circadian clock, modulating plant flowering responses under specific day lengths by regulating florigen levels. However, the COL gene family in Litchi chinensis Sonn. has not yet been characterized. In this study, we identified eight COL family members in litchi and classified them into three subgroups based on phylogenetic analysis. The analysis of cis-regulatory elements within the promoters of LcCOLs revealed a wide distribution of elements associated with light, hormone, and stress responses. Transcript expression profiling indicated that most LcCOLs exhibited relatively high expression levels in leaf buds, leaves, and young fruits. Diurnal expression analysis under natural photoperiod conditions revealed that the expression peaks of all LcCOLs, with the exception of LcCOL1, occurred during the nighttime. The heterologous overexpression of LcCOL7 and LcCOL8, the closest homologs to AtCO, in Arabidopsis thaliana significantly delayed the flowering time under both long-day (LD) and short-day (SD) conditions, indicating that these genes act as repressors of flowering. This study provides a foundational basis for elucidating the molecular mechanisms underlying litchi flowering regulation and identifies promising candidate genes for the molecular breeding of litchi flowering-related agronomic traits. Full article

Reticulon-like proteins shape the endoplasmic reticulum (ER) membrane network, yet the developmental and physiological roles of individual plant reticulon isoforms remain poorly understood. Here, we characterize an Arabidopsis RTNLB16 T-DNA allele, rtnlb16-1, that exhibits severe photoperiod-dependent growth retardation and chlorosis. Molecular analysis revealed that rtnlb16-1 is not a simple loss-of-function mutant: the T-DNA insertion deletes the 5′ region required for RTNLB16 splice variant 7, while a CaMV35S enhancer associated with the insertion drives overexpression of the remaining splice variants. This misexpression is enhanced under long-day photoperiods and reduced under continuous low light, paralleling the severity of the mutant phenotype and its partial rescue. RTNLB16.5-GFP localized mainly to the tubular ER network and punctate cell-boundary structures consistent with plasmodesmata-associated ER. Neither overexpression of RTNLB16 isoforms 1–6 nor CRISPR-Cas9 disruption of major RTNLB16 isoforms reproduced the rtnlb16-1 phenotype, supporting a model in which altered splice-variant stoichiometry, rather than simple loss or gain of function, underlies the developmental defects. Transcriptome profiling showed that rtnlb16-1 undergoes extensive photoperiod-dependent transcriptional reprogramming, including changes in defense, hormone-response, senescence, photosynthesis, and iron/redox-associated gene networks. Physiologically, rtnlb16-1 displayed enhanced recovery from dark-induced senescence, while both rtnlb16-1 and rtnlb16-2 showed reduced sensitivity to exogenous abscisic acid during germination. Together, these findings suggest that balanced expression of RTNLB16 splice variants is important for normal growth and for coordinating ER-associated stress, hormone, and senescence responses in Arabidopsis. Full article

Tropical maize often exhibits photoperiod sensitivity, which limits its adaptation to temperate regions. Understanding its proteomic dynamics under long-day conditions is therefore crucial for germplasm improvement. This study employed a Tandem Mass Tag (TMT)-based proteomic approach to investigate stage-specific protein expression patterns in the tropical maize inbred line QR273 under long-day conditions (16 h light/8 h dark). Seeds were cultivated in climate chambers, and leaves were collected at the four-leaf (P4) and nine-leaf (P9) stages. A total of 2881 differentially expressed proteins (DEPs) were quantified between the P4 and P9 stages, among which only 7 were upregulated and 2874 were downregulated at the P9 stage. Gene Ontology (GO) enrichment analysis revealed that these DEPs were significantly enriched in processes related to proteolysis, membrane components, and ATP binding. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed the enrichment of DEPs in amino acid biosynthesis, secondary metabolite biosynthesis, and aminoacyl-tRNA biosynthesis pathways. Protein–protein interaction (PPI) network analysis identified 60S ribosomal protein L12, adenosine 5′-phosphosulfate reductase, and RuvB helicase as core hub proteins. Based on functional annotation of representative DEPs, the DEPs were classified into four categories: 9 proteins related to storage material protection, 14 proteins related to protein modification, 12 proteins related to photosynthesis, and 25 proteins with other biological functions. Comparative analysis demonstrated a decrease in storage material protection, protein modification, and photosynthetic capacity at the P9 stage relative to the P4 stage. These findings provide insights into the proteomic dynamics underlying tropical maize development under long-day conditions and offer a theoretical basis for genetic improvement of tropical maize germplasm. Notably, inferences regarding nutrient reallocation based on DEP downregulation are derived solely from proteomic data and require further experimental validation. Full article

Cultivars of strawberry (Fragaria × ananassa) differ in photoperiodic responses, which influence the balance between vegetative and reproductive growth, shaping canopy development, biomass production, and water use efficiency (WUE). Using 3D point-cloud phenotyping, this study compared the canopy structure and WUE of the short-day cultivar ‘Sonata’ and long-day cultivar ‘Favori’ grown under identical greenhouse conditions. Cultivar-specific growth and water use traits were quantified using daily non-destructive 3D point cloud phenotyping combined with continuous whole-plant gravimetry, supported by manual and destructive measurements. Non-destructive estimates of plant height and digital biomass corresponded moderately to measurements (height: R² = 0.628; biomass: R² = 0.579; mean absolute percentage error (MAPE) = 13.86%). Growth analysis indicated similar relative growth rates between the two cultivars, whereas the crop growth rate was higher in ‘Sonata’ than in ‘Favori’. Integration of growth estimates with gravimetric records revealed higher period average WUE in ‘Sonata’ (3.1 mg g⁻¹) than in ‘Favori’ (2.5 mg g⁻¹). These results highlight the distinctive growth strategies of a canopy-driven pattern in ‘Sonata’ and a reproduction-driven pattern in ‘Favori’. The combined 3D phenotyping–gravimetry framework provides a high-resolution, non-destructive approach to quantify cultivar-specific growth and water use traits. Full article

Background: INDETERMINATE DOMAIN proteins (IDDs) are a plant-specific transcription factor family, and members of this family play crucial roles in regulating growth and development as well as environmental adaptation. However, a comprehensive analysis of the IDD family in soybean [Glycine max (L.) Merrill] is limited. Methods and Results: A total of 27 GmIDD genes were identified in the soybean genome, unevenly distributed across 14 chromosomes, and their encoded proteins all harbor a conserved INDETERMINATE (ID) domain with two Cys2His2 (C2H2) and two Cys2HisCys (C2HC) zinc finger motifs. Phylogenetic analysis classified these GmIDD genes into three subgroups. Soybean GmIDD genes exhibit high homology with their Arabidopsis thaliana IDD counterparts. Cis-acting element analysis indicated that the promoters of GmIDD genes are enriched in light-responsive elements (such as Box4), hormone-responsive elements (such as ABRE and AuxRR-core), and abiotic stress-responsive elements (such as MBS and LTR). The qRT-PCR results showed that GmIDD3/5/14/22/26 were upregulated under salt stress, while GmIDD8/9/10/12/16/17/19/20/23/24/25/27 were obviously downregulated during treatment. Under drought stress, the expression levels of GmIDD4/6/7/10/14/16/19/22/24/25/26/27 were upregulated during the treatment. The expression levels of GmIDD1/2/3/4/12/14/15/16/17/18/22/23/25/26 were induced by short-day conditions, whereas GmIDD9/13/19/21 were induced by long-day conditions in soybean leaves. Conclusions: This study provides a theoretical basis for further understanding the functions of the soybean IDD gene family in abiotic stress tolerance and photoperiod adaptability. Full article

Chronic exposure to artificial light at night (ALAN) is increasingly recognized as an environmental risk factor that disrupts circadian regulation of endocrine and metabolic systems. In this study, we investigated the effects of extreme ALAN on oxidative stress and gut microbiota composition in mice using two complementary experiments. In Experiment 1, adult female mice were maintained under either as a standard 12 h light/12 h dark cycle (12 h group) or continuous 24 h light exposure (24 h group) throughout pregnancy and lactation. In Experiment 2, the offspring from the 12 h group were maintained under the same photoperiod, whereas offspring from the 24 h group were divided into a 12 h light/12 h dark group or a continuous 24 h light group, with treatments initiated on postnatal day 19 and continued until 2 months of age. For all 12 h groups, light exposure occurred from 8:00 to 20:00. Compared with dams in the 12 h group, dams exposed to continuous light exhibited significantly increased catalase activity, while their offspring maintained under the 12 h photoperiod showed elevated glutathione levels. No significant changes were detected in immune organ indices. These results suggest that extreme ALAN modulates antioxidant defenses, potentially reflecting adaptive responses to oxidative stress. Moreover, offspring exposed early to extreme ALAN showed significantly reduced gut microbial α-diversity, accompanied by decreased abundances of Firmicutes, Bacteroidota, Campylobacterota, and Desulfobacterota, and an increase in Proteobacteria. Notably, Verrucomicrobiota and Akkermansia failed to recover following photoperiod normalization, indicating persistent microbiota dysbiosis. Overall, these findings demonstrate that extreme ALAN induces oxidative stress and long-lasting alterations in gut microbiota composition, highlighting potential health risks associated with night-time light pollution. Full article

Atlantic salmon (Salmo salar) is an important dietary source of health-promoting long-chain polyunsaturated fatty acids (PUFAs). As rearing conditions significantly influence fillet quality, this study evaluated the effects of warm and cool rearing temperature and photoperiod regimes on salmon growth, lipid profiles, and antioxidant capacity. Atlantic salmon (210 days old) were reared for 92 days under low temperature (14 °C, 12 h light) or high temperature (21 °C, 24 h light) conditions to simulate relevant seasonal conditions, winter and summer respectively. At day 302, conditions were reversed to create low-to-high (L→H) and high-to-low (H→L) treatments, continuing until day 362. Growth parameters, muscle lipid content, fatty acid profile, and antioxidant activity were measured at 302 and 362 days. Lipid content and fatty acid profile were also measured based on fillet location and fish sex. High rearing temperatures accelerated weight gain and increased total and neutral lipid contents, but elevated saturated fatty acids (SFA) and decreased PUFAs in structural polar lipids. High temperatures also significantly increased antioxidant activity, indicating elevated oxidative stress. Conversely, low temperatures suppressed growth but preserved essential PUFAs and maintained oxidative stability. Following the temperature shift, the H→L group had enriched polar lipids with PUFAs and maintained oxidative stability. On the other hand, L→H group showed lower PUFAs accumulation in polar lipid and enhanced oxidative stress. Total lipid content was higher in the head region, followed by the middle and tail sections of the fillet. However, fatty acid composition remained largely uniform across all three sections of the fillet. There were no significant differences in total lipid content between fish sexes. In conclusion, production efficiency and nutritional quality can be optimized by initially rearing salmon at high temperatures to promote rapid growth, followed by low temperature finishing phase to increase essential PUFA content and maintain oxidative stability. Full article

Tea is a vital economic crop in China, with many anthocyanin-rich cultivars having been bred. Photoperiod is an important environmental factor that regulates anthocyanin production in plants. Nonetheless, the precise mechanisms by which photoperiod affects anthocyanin biosynthesis in tea plants remain unclear. In this study, the purple-leaf cultivar Camellia sinensis ‘Ziyan’ was exposed to three different photoperiods: 8 h/16 h (light/dark, short-day, SD), 14 h/10 h (light/dark, medium-day, MD), and 20 h/4 h (light/dark, long-day, LD). A comprehensive analytical approach, including transcriptomics, enzymology, and quantitative anthocyanin analysis, was used to uncover the molecular and biochemical processes regulating anthocyanin synthesis in purple-leaf tea plants grown under varying photoperiods. The results showed that the delphinidin, cyanidin, pelargonidin, and total anthocyanin contents in the long-day treatment were 178.10%, 92.37%, 50.40%, and 148.76% higher, respectively, than those in the short-day treatment. Under long-day conditions, all structural genes associated with anthocyanin synthesis were upregulated, and enzymatic activities related to anthocyanin synthesis were significantly increased. Furthermore, the regulatory genes (MYB1, MYB73, MYB111, MYB48, MYB75, MYB113, MYB5, MYB12, MYB5a, MYB5b, and WRKY41) were differentially expressed under short- and long-day treatments. These findings suggest that extended photoperiods activate the expression of structural genes through gene regulation and enhancement of enzymatic activity, thereby facilitating anthocyanin biosynthesis. This study provides novel insights into the photoperiodic regulation of anthocyanin biosynthesis in tea plants. Full article

Oxalis tuberosa (oca) is a tuber crop native to the Andes, valued for its nutrition but understudied genetically. Its strict short-day (SD) tuberization suggests a photoperiodic control mechanism similar to that of potato, where an FT-like protein acts as a mobile “tuberigen” signal. To identify this key regulator, we generated a de novo genome assembly for oca using long- and short-read sequencing. Integrated transcriptomic analysis of leaves under long-day (LD) and SD conditions, along with stems, roots, and tubers, enabled gene annotation and expression analysis. Our study focused on the Phosphatidylethanolamine-Binding Protein (PEBP) gene family, the source of florigen and tuberigen signals. We identified 23 OtPEBP genes and characterized their expression patterns. Among these, we discovered three FT-like homologs that are specifically and strongly upregulated in leaves under SD conditions. We therefore propose these genes as the prime candidates for the mobile tuberigen signal in oca. This work provides the foundational genomic resource for O. tuberosa and advances our understanding of the conserved photoperiodic network controlling storage organ formation beyond the Solanaceae family. Full article

Photoperiod and seasonality influence reproduction and lactation in sheep, but their effects on milk hormones, milk composition, and lamb growth are not fully understood. This study assessed the effect of season on milk prolactin, leptin, and insulin concentrations, milk chemical composition, lactation performance, and lamb growth in Polish Mountain ewes. Forty ewes were divided into the following two groups: short-day (lambing in December, n = 20) and long-day (lambing in May, n = 20). Milk samples were collected on days 5, 15, 25, 35, and 45 of lactation. Ewes in the long-day photoperiod had higher milk yield (p < 0.01) and higher prolactin and insulin concentrations (p < 0.01), whereas leptin concentrations did not differ seasonally. Milk from short-day ewes was characterized by higher dry matter and fat content (p < 0.01) and higher protein and lactose content (p < 0.05). Lambs from the long-day group achieved higher mean daily gain (p < 0.01). These results indicate that photoperiod influences lactation performance, milk composition, and offspring growth through seasonal hormonal and metabolic mechanisms, suggesting that appropriate lambing timing and day length manipulation can improve milk production efficiency and lamb growth in practical sheep production systems. Full article

Cymbidium faberi Rolfe is a Chinese flower famous due to its beautiful floral pattern and strong floral scent and is also a threatened terrestrial orchid. Moreover, the traditional propagation method through tillers and symbiotic seed germination with the correct fungus under nature conditions could not meet conservation and commercial needs. Here, an efficient procedure for asymbiotic seed germination and in vitro seedlings development of C. faberi was successfully established through evaluation of time of seed collecting, seed pretreatments, light conditions and composition of culture media, respectively. Seed pretreatment with 1% NaClO for 30 min, dark culture on 1/4 MS medium containing 0.5 mg·L⁻¹ 6-BA and 0.1 mg·L⁻¹ NAA for 30 days and subsequent long day condition (14 h light/10 h dark photoperiod) culture on this medium for 30 days could obviously enhance the seed germination rate of C. faberi. The highest germination rate (85.0 ± 0.79%) was achieved when seeds were collected at 120 d after cross-fertilization, and then germination percentages progressively decreased. Furthermore, histological analyses from protocorm formation to seedling growth were explored. This study not only offers a reliable and scalable system for mass propagation to meet commercial and conservation demands but also serves as a foundational reference for physiological and molecular studies in Cymbidium and related orchids. Full article

Reproductive seasonality in birds represents a key ecological adaptation that ensures synchronization between breeding activity and optimal environmental conditions for offspring survival and development. Photoperiod is the primary cue regulating the hypothalamic–pituitary–gonadal (HPG) axis, through brain photoreceptors and pineal melatonin secretion. Increasing day length induces thyroid hormone activation by hypothalamic type 2 deiodinase (DIO2), stimulates gonadotropin-releasing hormone (GnRH) secretion, and promotes gonadal growth, whereas prolonged exposure to long days triggers photorefractoriness, which has been linked to increased hypothalamic type 3 deiodinase (DIO3) expression in several studies, although the causal role of this enzyme remains under investigation. Secondary environmental modulators, such as temperature, food supply, precipitation, and social interactions, also play crucial roles in fine-tuning reproductive timing. Moreover, anthropogenic factors like artificial light at night can disrupt circadian and seasonal regulation, causing mismatches between breeding and food availability. Evidence from diverse species, including passerines, galliforms, waterfowl, and raptors, demonstrates both conserved mechanisms and ecological plasticity, with tropical and urban species showing more opportunistic breeding strategies. These findings highlight the multifactorial and flexible nature of avian reproductive cycles, underlining their vulnerability to climate change and habitat anthropization. Considering this, this review aimed to understand the neuroendocrine and environmental control of seasonality and to offer an integrative perspective on how light, hormones, and environmental factors interact to shape seasonal reproduction in wild birds. Full article

Background: White adipose tissue (WAT) exhibits diurnal oscillations regulated by clock genes, which autonomously control its functionality. These rhythms are modulated by the central clock and external factors, such as light exposure and diet. Flavanols, phenolic compounds known for their beneficial metabolic effects, have been shown to modulate the expression of clock genes. This study explored the impact of flavanols on clock gene expression in WAT explants from lean and obese rats under changes in light/dark cycles. Methods: WAT explants were obtained from 24 Fischer rats fed a standard diet (STD) or cafeteria diet (CAF) for seven weeks. During the final week, rats were changed to short (6 h of light, L6) or long (18 h of light, L18) photoperiods. CAF-fed rats were also administered a grape seed (poly)phenol-rich extract (GSPE) (25 mg/kg) or vehicle (VH). After sacrifice, WAT explants were collected every 6 h starting at 8 a.m. the following day (CT0, CT6, CT12, CT18, and CT24). Results: The results showed that under L18 conditions, STD-fed rats displayed oscillations in Bmal1, Cry1, Per1, and Rev-erbα clock gene expression, whereas many of these rhythms were disrupted under L6 conditions. Moreover, the administration of the CAF diet also resulted in the loss of clock gene circadian oscillations in the WAT explants. GSPE administration restored the oscillation of these clock genes under L18 and L6 conditions. Conclusions: These findings highlight the potential zeitgeber role of flavanols in modulating WAT peripheral clocks and their capacity to improve metabolic and circadian regulation under conditions of diet- and photoperiod-induced disruption. Full article