Search Results (243)

Leaf phenology of trees responds to temperature and photoperiod cues, mediated by underlying genes and plasticity. However, uncertainties remain regarding how smaller-scale phenological variation in cold-limited regions has been affected by modified selection pressures from herbivores, pathogens, and climate conditions, and whether this leaves genetic signatures allowing for projections of future responses. We investigated environmental correlates and genetic variation putatively associated with spring and autumn leaf phenology in northern range margin oak (Quercus robur L.) populations in Sweden (55.6° N–60.8° N). Results suggested that budburst occurred later at higher latitudes and in locations with colder spring (April) temperatures, whereas leaf senescence occurred earlier at higher latitudes. Several candidate loci associated with phenology were identified (n = 40 for budburst and 47 for leaf senescence), and significant associations between these loci and latitude were detected. Functions associated with some of the candidate loci, as identified in previous studies, included host defence and heat stress tolerance. The proportion of polymorphic candidate loci associated with budburst decreased with increasing latitude, towards the range margin. Overall, the Swedish oak population seems to comprise genetic diversity in phenology-related traits that may provide resilience to a rapidly changing climate. Full article

Camellia azalea is an endemic species within the genus Camellia that exhibits the trait of summer flowering, which is of significant ornamental and research value. Nevertheless, research on the regulatory mechanisms of flower formation in C. azalea is still limited, so in this study, transcriptome sequencing and analysis of endogenous hormone contents were conducted at three distinct growth stages: floral induction, floral organ maturation, and anthesis. Illumina sequencing yielded a total of 20,643 high-quality unigenes. Comparative analyses of representative samples from the three growth stages identified 6681, 1925, and 8400 differentially expressed genes (DEGs), respectively. These DEGs were further analyzed for functional enrichment using the GO and KEGG databases. Additionally, core genes from each flowering pathway underwent expression pattern analysis and network diagram construction. This revealed that the flower development process in C. azalea is linked to the specific expression of the genes involved in the photoperiod, temperature, and autonomous pathways and is subject to comprehensive regulation by multiple pathways. Further analysis of the dynamic trends of five endogenous hormone contents and plant hormone signal transduction genes revealed significant differences in the requirements of endogenous hormones, such as gibberellins and indoleacetic acid, by C. azalea at distinct growth stages. Additionally, the majority of genes on the phytohormone signal transduction pathway demonstrated a high correlation with the changes in the contents of each hormone. The present study integrates physiological and molecular approaches to identify key genes and metabolic pathways that regulate the summer flowering of C. azalea, thereby laying a theoretical foundation for further investigations into its flowering mechanism and related functional genes. Full article

The postharvest quality of lettuce (Lactuca sativa) is significantly influenced by the lighting environment during storage. This study evaluated the effects of green LEDs at 500 nm and 530 nm, white LEDs (400–700 nm), and dark storage on lettuce quality over 14 days at 5 °C. All treatments were applied at 10 µmol m⁻² s⁻¹ under a 12 h photoperiod. Quality parameters measured included moisture loss, relative water content (RWC), photosynthetic rate, chlorophyll content (SPAD), total soluble solids (TSSs), electrolyte leakage (EL), color change (∆E), texture (crispness), and overall visual quality (OVQ). Lettuce stored under green LEDs, particularly 530 nm, exhibited superior postharvest quality. Compared to dark storage, 530 nm reduced moisture loss by 7.1%, increased RWC by 9.2%, and reduced transpiration rate. The green light preserved photosynthetic activity (43% decline vs. 77% in the dark), increased TSS, reduced color change by 42%, improved crispness by 46.1%, and limited EL to 54.5%. Shelf life was extended by approximately four days. The 500 nm treatment showed notable improvements, including an 8.4% reduction in moisture loss, 8.2% higher RWC, a smaller photosynthesis decline (25%), and the lowest EL (53.1%). It improved color retention (∆E reduced by 45.3%) and crispness (46.8%). Both green wavelengths effectively maintained lettuce quality during cold storage, with 530 nm being the most effective overall. These results suggest that targeted green LED lighting is a promising, energy-efficient strategy to preserve postharvest quality and extend shelf life in leafy greens. Full article

In Arctic residents, blood lipids fluctuate seasonally in response to changes in light exposure (LE) patterns. This study investigates which aspects of LE (timing, dynamic range, and duration) are related to lipid profiles. We analyzed actigraphy data measuring LE and blue light exposure (BLE) along with blood determinations from 27 residents across different seasons. We assessed circadian parameters of melatonin in a subset of participants. We found that features of BLE and melatonin significantly predicted lipids: An earlier BLE acrophase was associated with higher HDL-C (β = −0.246, p = 0.013). Nighttime BLE was positively associated with TC (β = 0.290, p = 0.008) and LDL-C (β = 0.253, p = 0.025). The normalized circadian amplitude of BLE was inversely associated with the TG/HDL ratio (β = −0.384, p < 0.001). Finally, earlier melatonin was associated with lower TG/HDL (β = 0.464, p = 0.007). Results remained significant after adjusting for co-factors of photoperiod duration, age, sex, and indigeneity. These findings suggest that patterns of LE (circadian light hygiene) could be a way to improve cardiovascular health. Full article

Temperature is a critical factor affecting the development and population dynamics of many organisms. An organism’s ability to withstand extreme temperature events, such as heat waves, will become increasingly important as the severity, duration, and frequency of these events continue to rise worldwide due to global warming. Knowledge on the effects of heat stress on both pests and their natural enemies will thus be crucial for keeping biological control and pest control programs effective in future. This research aimed to study the effect of short-term heat stress on the predatory mite Phytoseiulus persimilis, which is one of the important natural enemies utilized as a biocontrol agent against spider mites such as Tetranychus urticae. The experiments assessed the immature developmental time of P. persimilis after a four-hour incubation of eggs at high temperatures, namely 36, 38, 40, and 42 °C, as well as 85 ± 5% RH and a 16:8 h photoperiod (L:D). After adult females emerged, they were exposed to the same conditions again and the population parameters were monitored. The results demonstrated that the immature development time decreased as temperature increased, with the shortest development duration of 5.30 days seen in eggs exposed to 40 °C, while the eggs exposed to 42 °C did not hatch. Female and male adult longevity decreased significantly as the temperature increased. Fecundity, the adult pre-ovipositional period, and the total pre-ovipositional period were lowest following the 40 °C treatment. The population parameters of P. persimilis, including r and λ, reached their highest values in mites treated at 36 °C, and were significantly higher than in the control group. Addressing these challenges through targeted research and adaptive management is essential to sustaining the efficiency of P. persimilis in biocontrol programs, particularly in the context of global climate change. Full article

Drosophila suzukii is a successful invasive insect species responsible for agricultural losses. The key to its prowess is the ability to swiftly adapt to new environments through various genetic mechanisms, including fast accommodation of mutations and gene expression fine-tuning. Piezo and nanchung (nan) genes are linked to circadian clock-related behaviors and, therefore, are expected to readily respond to stress stimuli. Herein, we compared the DNA sequences of Piezo, nan, and αTubulin at 67C, a highly conserved housekeeping gene, in ICDPP-ams-1, a Romanian local population of D. suzukii, and two well-annotated reference populations from the United States of America and Japan. Our results imply that short-term evolutionary accumulated single nucleotide and indel variants are overrepresented within introns, a propensity evaluated through the mutation accumulation tendency (MAT) original parameter. Piezo and nan gene expression under photoperiodicity changes challenges were assessed in a series of experiments on three groups of individuals from ICDPP-ams-1. We found that both genes are upregulated in females if their customary circadian rhythm is affected, a trend seemingly reverting if, after an initial perturbation, the circadian clock is reset to its initial timing. In conclusion, we found that both highly conserved and adaptability-related genes are rapidly evolving and that Piezo and nan have a fast functional reaction to circadian clock changes by modifying their gene expression profiles. Full article

Indoor farming presents a sustainable response to urbanization and climate change, yet optimizing light use efficiency (LUE) remains vital for maximizing crop yield and minimizing energy use. This study introduces an IoT-based framework for adaptive light management in controlled environments, using lettuce (Lactuca sativa L.) as a model crop due to its rapid growth and sensitivity to light spectra. The system integrates advanced LED lighting, real-time sensors, and cloud-based analytics to enhance light distribution and automate adjustments based on growth stages. The key findings indicate a 20% increase in energy efficiency and a 15% improvement in lettuce growth compared to traditional static models. Novel metrics—Light Use Efficiency at Growth stage Canopy Level (LUEP) and Lamp Level (LUEL)—were developed to assess system performance comprehensively. Simulations identified optimal growth conditions, including a light intensity of 350–400 µmol/m²/s and photoperiods of 16–17 h/day. Spectral optimization showed that a balanced blue-red light mix benefits vegetative growth, while higher red content supports flowering. The framework’s feedback control ensures rapid (<2 s) and accurate (>97%) adjustments to environmental deviations, maintaining ideal conditions throughout growth stages. Comparative analysis confirms the adaptive system’s superiority over static models in responding to dynamic environmental conditions and improving performance metrics like LUEP and LUEL. Practical recommendations include stage-specific guidelines for light spectrum, intensity, and duration to enhance both energy efficiency and crop productivity. While tailored to lettuce, the modular system design allows for adaptation to a variety of leafy greens and other crops with species-specific calibration. This research demonstrates the potential of IoT-driven adaptive lighting systems to advance precision agriculture in indoor environments, offering scalable, energy-efficient solutions for sustainable food production. Full article

The relationship between the gut microbiota and photoperiod has received widespread attention, and it is necessary to explore the probable common mechanisms involved. We tested whether the gut microbiota of animals with similar light-regulated life history traits would also exhibit consistent responses to the photoperiod. Here, two species of long-day breeders, striped hamsters (Cricetulus barabensis) and Djungarian hamsters (Phodopus sungorus), were raised under different photoperiods (long daylight, LD; short daylight, SD), and their cecal contents were collected to assess the gut microbiota. There was no difference in the gut microbial diversity between the groups of striped hamsters; however, in the Djungarian hamsters, lower Chao and Shannon indices were observed in the LD group than in the SD group. The bacterial community variation in the striped hamsters was reflected mainly in the enrichment of the genera Enterorhabdus and Jeotgalicoccus in the LD group; meanwhile, more taxa with significant changes in relative abundance under different photoperiods were found in the Djungarian hamsters, such as the enrichment of the genera Lactobacillus and Faecalibaculum in the LD group and the enrichment of the genera Ruminococcus and Colidextribacter in the SD group. The LD conditions substantially reduced the complexity of the gut microbial network in the Djungarian hamsters and increased the R² value of the striped hamster gut microbiota under fitting with a neutral community model. Moreover, the potential gut microbial functions in the striped hamsters were relatively stable, but variations were observed in multiple pathways between the groups of Djungarian hamsters. These results contribute to the understanding of host species specificity in the response of the gut microbiota to external changes. Full article

Sowing date significantly affects plant growth, development, and yield, holding a crucial role in soybean cultivation. This study was conducted in the southern coastal region of Korea under recent climate change conditions to investigate the effects of five different sowing dates on climatic characteristics, growth, and yield. Compared to historical data, the southern coastal region has experienced a consistent increase in average temperature during the soybean cultivation period, along with frequent abnormal summer climate events such as concentrated heavy rainfall and monsoons. These climate changes prolonged the vegetative growth period in earlier sowings, leading to an increased risk of lodging at maturity due to vigorous vegetative growth. Furthermore, earlier sowing delayed flowering and exposed plants to longer post-flowering photoperiods, consequently reducing the number of pods. Therefore, in the southern coastal region of Korea, it is crucial to re-evaluate conventional sowing practices and establish region-specific optimal dates, with careful consideration given to postponing the soybean sowing date to late June in order to enhance yield stability and improve the feasibility of double-cropping systems by shortening the growing period. Full article

The circadian rhythm of an animal’s body color change is crucial for its survival and adaptation to the environment, with photoperiod serving as a primary “zeitgeber” that significantly affects the circadian rhythm of color change. To explore the circadian body color change in juvenile Chinese giant salamanders (Andrias davidianus), four distinct photoperiod regimens were established, including the DD group (constant darkness), the LD12:12 group (12 h photophase, 12 h scotophase), the LD16:8 group (16 h photophase, 8 h scotophase), and the LD8:16 group (8 h photophase, 16 h scotophase). Reflectance spectra of dorsal skin were measured every 4 h over a 24 h cycle, with data collected every other day for three consecutive days, totaling 72 h. Reflectance spectra were converted into colorimetric variables to analyze circadian patterns. The results demonstrated that juvenile A. davidianus exhibited highly significant circadian rhythmicity under different photoperiods, with their body color becoming darker during the photophase (mean brightness: 14.650 ± 0.629 to 16.385 ± 1.301) and lighter during the scotophase (mean brightness: 16.473 ± 0.875 to 34.422 ± 2.692). Photoperiod alterations significantly affected the rhythm parameters (mesor, amplitude, and acrophase) of mean brightness variation. Compared with the LD12:12 group, the LD16:8 group (extended photophase) reduced rhythm mesor by 1.415, decreased amplitude by 0.988, and induced a 1.510 h acrophase delay. Conversely, the LD8:16 group (extended scotophase) increased rhythm mesor by 2.141 and amplitude by 2.919. These findings indicate that the circadian rhythm of body color change in juvenile A. davidianus is coordinately regulated by endogenous circadian rhythms and exogenous photoperiodic signals. The findings of this study provide a theoretical foundation for the conservation and management of A. davidianus. Full article

Among physiological parameters, total locomotor activity (TLA) and heart rate (HR) are used as physiological indicators in animal welfare evaluations. The present study aimed to simultaneously record for 24 h the TLA and HR of ten clinically healthy horses housed in conventional individual boxes subjected to a natural photoperiod and temperature. An actigraphy-based data logger was placed on the headstall, and an equine HR monitor was placed around the chest to monitor TLA and HR, respectively. Activity was monitored with 5 min sampling intervals and HR with 5 s intervals. To make the data points uniform, the means of 5 min intervals were calculated. Both investigated parameters showed a daily rhythmicity with a diurnal acrophase (locomotor activity 17:05 ± 1:15 arbitrary unit; heart rate 16.40 ± 0.30 beats/min). Robustness of the rhythm was 17.95 ± 10.53% and 37.05 ± 0.63% for the TLA and HR. A positive correlation was observed between the two investigated parameters in each horse, r = 0.48 ± 0.07, p < 0.0001. Change in TLA is a good index for success of management. Its positive correlation with daily HR monitoring confirms the use of these two physiological parameters for an objective on-farm welfare assessment. The application of new technologies for the simultaneous recording of physiological indexes of animals’ welfare can be a useful instrument. Full article

The effects of the combination of the light intensity and photoperiod on the yield of virus-free potato and resource utilization are still poorly understood, especially under the same daily light integral. Here, we tested the responses of virus-free potato in terms of plant growth, photosynthesis, and the tuber yield to four light intensity and photoperiod combinations (T1, 200 μmol m⁻² s⁻¹ and 16.5 h; T2, 300 μmol m⁻² s⁻¹ and 11 h; T3, 400 μmol m⁻² s⁻¹ and 8.25 h; T4, 500 μmol m⁻² s⁻¹ and 6.6 h) under the same daily light integral. The tuber number and dry weight increased with the shortening of the photoperiod. The smaller number of tubers under the T1 treatment was due to the poor transport of photosynthates in the leaves and the uneven distribution of photosynthates in the tubers during the tuber formation stage. Changes in the light intensity and photoperiod combination did not significantly impact the distribution ratio of photosynthates between plants and tubers at the tuber growth stage; they only caused adjustments in the total amount of photosynthates. In addition, the photoinhibition under T1 was caused by the long photoperiod and that under T4 was caused by the high light intensity. However, the higher content of carotene in the T4 treatment alleviated the adverse effects of photoinhibition on the tuber yield. The results showed that the number and growth of tubers were extremely negatively correlated with shoot growth and extremely positively correlated with the accumulation rate of photosynthates in the plant and the tubers per day. In terms of energy consumption and the cost of the light source, we recommend the light intensity and photoperiod combinations of 300 μmol m⁻² s⁻¹ and 11 h or 400 μmol m⁻² s⁻¹ and 8.25 h to cultivate virus-free potato in plant factories. Full article

Photoperiod regulates reproductive physiology in many fishes, but its sex-specific molecular effects under artificial manipulation remain unclear, especially in cold-water species. In this study, we investigated whether photoperiod manipulation during the reproductive season could modulate the rate and efficiency of gonadal development in the Amur minnow (Phoxinus lagowskii). High-throughput RNA sequencing was used to analyze transcriptomic responses of gonadal tissues under three photoperiod regimes: natural light (12L:12D), continuous light (24L:0D), and continuous darkness (0L:24D) over a 9-week experimental period. Our results revealed distinct sex-specific gonadal responses to photoperiodic changes. In males, continuous light significantly promoted spermatogenesis by upregulating meiosis-related genes (REC114 and syp3) and steroid biosynthesis. In females, prolonged light exposure induced ovarian stress, evidenced by vitellogenin (Vtg3) upregulation and retinoic acid suppression, whereas continuous darkness promoted lipid storage via downregulation of gluconeogenesis (PC and Fbp2) and fatty acid oxidation (ACSL1a). Additionally, immune activation, marked by IL1RAPL1-A upregulation, was observed in all groups except continuous-light males, with females exhibiting broader immune pathway engagement. These findings provide novel insights into the regulatory mechanisms of photoperiod-induced gonadal development and highlight potential strategies for optimising photoperiod management in cold-water fish aquaculture. Full article

Human nutrition is inherently associated with the cultivation of vegetables, grains, and fruits, underscoring the critical need to understand and manipulate the balance between vegetative and reproductive development in plants. Despite the vast diversity within the plant kingdom, these developmental processes share conserved and interconnected pathways among angiosperms, predominantly involving age, vernalization, gibberellin, temperature, photoperiod, and autonomous pathways. These pathways interact with environmental cues and orchestrate the transition from vegetative growth to reproductive stages. Related to this, there are two key genes belonging to the same Phosphatidylethanolamine-binding proteins family (PEBP), the FLOWERING LOCUS T (FT) and TERMINAL FLOWER 1 (TFL1), which activate and repress the floral initiation, respectively, in different plant species. They compete for transcription factors such as FLOWERING LOCUS D (FD) and 14-3-3 to form floral activation complexes (FAC) and floral repression complexes (FRC). The FT/TFL1 mechanism plays a pivotal role in meristem differentiation, determining developmental outcomes as determinate or indeterminate. This review aims to explore the roles of FT and TFL1 in plant architecture and floral induction of annual and perennial species, together with their interactions with plant hormones. In this context, we propose that plant development can be modulated by the response of FT and/or TFL1 to plant growth regulators (PGRs), which emerge as potential tools for mitigating the adverse effects of environmental changes on plant reproductive processes. Thus, understanding these mechanisms is crucial to address the challenges of agricultural practices, especially in the face of climate change. Full article

Autumn phenology plays a crucial role in shaping the capacity for carbon sequestration. However, understories, a vital yet often neglected ecosystem component, have complicated autumn phenology prediction. We address the challenge of monitoring understory phenological dynamics by using a UVL4 trail camera and selecting appropriate deriving processes and vegetation indices (VIs). We found the understory photoperiod was on average 1.88 h shorter than the canopy’s, while the understory temperature was 2.11 °C higher than the canopy’s open-air temperature. The maximum temperature inside the understories was on average 1.37 °C lower than in open-air conditions. Specifically, the 60% quantile of the daily VI in July and the 15% quantile in November effectively captured the prolonged minimum and the minimum in the VI time series when applying logistic modeling. The excess green vegetation index (ExG) outperformed other VIs in estimating understory greenness change. The cold degree days model (CDD) and low-temperature and photoperiod multiplicative model (TPM) revealed that senescence progressed from the upper crown downwards, causing over 13 days of lag in the understory. These findings offer a new perspective on quantifying autumn phenology in subtropical forests and provide insights into asynchronous changes in vertical microclimatic gradients in Earth system and vegetation models. Full article