Transcriptomic analysis provides insights into the molecular mechanism of melatonin-mediated cadmium tolerance in Medicago sativa L.

Cadmium (Cd), a toxic element, often makes a serious threat to plant growth and development. Previous studies found that melatonin (Mel) reduced Cd accumulation and reestablished the redox balance to alleviate Cd stress in Medicago sativa L., however, the complex molecular mechanisms are still elusive. Here, comparative transcriptome analysis and biochemical experiments were conducted to explore the molecular mechanisms of Mel in enhancing Cd tolerance. Results showed that 7237 differentially expressed genes (DEGs) were regulated by Mel pretreatment to Cd stress compared to the control condition in roots of Medicago sativa L. Besides, in comparison with Cd stress alone, Mel upregulated 1081 DEGs, and downregulated 1085 DEGs. These DEGs were mainly involved in the transcription and translation of genes and folding, sorting and degradation of proteins, carbohydrate metabolism, and hormone signal network. Application of Mel regulated the expression of several genes encoding ribosomal protein and E3 ubiquitin-protein ligase involved in folding, sorting and degradation of proteins. Moreover, transcriptomic analyse suggested that Mel might regulate the expression of genes encoding pectin lyase, UDP-glucose dehydrogenase, sucrose-phosphate synthase, hexokinase-1, and protein phosphorylation in the sugar metabolism. Therefore, these could promote sucrose accumulation and subsequently alleviate the Cd damage. In conclusion, above findings provided the mining of important genes and molecular basis of Mel in mitigating Cd tolerance and genetic cultivation of Medicago sativa L.

Theanine metabolism and transport in tea plants (Camellia sinensis L.): advances and perspectives.

Theanine, a tea plant-specific non-proteinogenic amino acid, is the most abundant free amino acid in tea leaves. It is also one of the most important quality components of tea because it endows the "umami" taste, relaxation-promoting, and many other health benefits of tea infusion. Its content in tea leaves is directly correlated with the quality and price of green tea. Theanine biosynthesis primarily occurs in roots and is transported to new shoots in tea plants. Recently, great advances have been made in theanine metabolism and transport in tea plants. Along with the deciphering of the genomic sequences of tea plants, new genes in theanine metabolic pathway were discovered and functionally characterized. Theanine transporters were identified and were characterized on the affinity for: theanine, substrate specificity, spatiotemporal expression, and the role in theanine root-to-shoot transport. The mechanisms underlying the regulation of theanine accumulation by: cultivars, seasons, nutrients, and environmental factors are also being rapidly uncovered. Transcription factors were identified to be critical regulators of theanine biosynthesis. In this review, we summarize the progresses in theanine: biosynthesis, catabolism, and transport processes. We also discuss the future studies on theanine in tea plants, and application of the knowledge to crops to synthesize theanine to improve the health-promoting quality of non-tea crops.

Compact multicolor two-photon fluorescence microscopy enabled by tailorable continuum generation from self-phase modulation and dispersive wave generation.

By precisely managing fiber-optic nonlinearity with anomalous dispersion, we have demonstrated the control of generating plural few-optical-cycle pulses based on a 24-MHz Chromium:forsterite laser, allowing multicolor two-photon tissue imaging by wavelength mixing. The formation of high-order soliton and its efficient coupling to dispersive wave generation leads to phase-matched spectral broadening, and we have obtained a broadband continuum ranging from 830 nm to 1200 nm, delivering 5-nJ pulses with a pulse width of 10.5 fs using a piece of large-mode-area fiber. We locate the spectral enhancement at around 920 nm for the two-photon excitation of green fluorophores, and we can easily compress the resulting pulse close to its limited duration without the need for active pulse shaping. To optimize the wavelength mixing for sum-frequency excitation, we have realized the management of the power ratio and group delay between the soliton and dispersive wave by varying the initial pulse energy without additional delay control. We have thus demonstrated simultaneous three-color two-photon tissue imaging with contrast management between different signals. Our source optimization leads to efficient two-photon excitation reaching a 500-µm imaging depth under a low 14-mW illumination power. We believe our source development leads to an efficient and compact approach for driving multicolor two-photon fluorescence microscopy and other ultrafast investigations, such as strong-field-driven applications.

Crosstalk between Melatonin and Reactive Oxygen Species in Plant Abiotic Stress Responses: An Update.

Melatonin acts as a multifunctional molecule that takes part in various physiological processes, especially in the protection against abiotic stresses, such as salinity, drought, heat, cold, heavy metals, etc. These stresses typically elicit reactive oxygen species (ROS) accumulation. Excessive ROS induce oxidative stress and decrease crop growth and productivity. Significant advances in melatonin initiate a complex antioxidant system that modulates ROS homeostasis in plants. Numerous evidences further reveal that melatonin often cooperates with other signaling molecules, such as ROS, nitric oxide (NO), and hydrogen sulfide (H2S). The interaction among melatonin, NO, H2S, and ROS orchestrates the responses to abiotic stresses via signaling networks, thus conferring the plant tolerance. In this review, we summarize the roles of melatonin in establishing redox homeostasis through the antioxidant system and the current progress of complex interactions among melatonin, NO, H2S, and ROS in higher plant responses to abiotic stresses. We further highlight the vital role of respiratory burst oxidase homologs (RBOHs) during these processes. The complicated integration that occurs between ROS and melatonin in plants is also discussed.

Molecular hydrogen-induced salinity tolerance requires melatonin signalling in Arabidopsis thaliana.

Melatonin (MT) plays positive roles in salinity stress tolerance. However, the upstream signalling components that regulate MT are poorly understood. Here, we report that endogenous MT acts downstream of molecular hydrogen (H2 ) in the salinity response in Arabidopsis. The addition of hydrogen-rich water and expression of the hydrogenase1 gene (CrHYD1) from Chlamydomonas reinhardtii increased endogenous H2 and MT levels and enhanced salinity tolerance. These results were not observed in the absence of serotonin N-acetyltransferase gene (SNAT). H2 increased the levels of SNAT transcripts in the wild-type and CrHYD1 lines, which had lower Na+ /K+ ratios and higher levels of ion transport-related gene transcripts. These changes were not observed in atsnat/CrHYD1-4 hybrids. The increased MT-dependent Na+ extrusion observed in the CrHYD1 plants resulted, at least in part, from enhanced Na+ /H+ antiport across the plasma membrane. The endogenous H2 -induced MT-dependent regulation of ion and redox homeostasis was impaired in the atsnat/CrHYD1-4 hybrids. Taken together, these results demonstrate that MT-induced salinity tolerance is induced by a H2 signalling cascade that regulates ion and redox homeostasis in response to salinity.

Melatonin Confers Plant Cadmium Tolerance: An Update.

Cadmium (Cd) is one of the most injurious heavy metals, affecting plant growth and development. Melatonin (N-acetyl-5-methoxytryptamine) was discovered in plants in 1995, and it is since known to act as a multifunctional molecule to alleviate abiotic and biotic stresses, especially Cd stress. Endogenously triggered or exogenously applied melatonin re-establishes the redox homeostasis by the improvement of the antioxidant defense system. It can also affect the Cd transportation and sequestration by regulating the transcripts of genes related to the major metal transport system, as well as the increase in glutathione (GSH) and phytochelatins (PCs). Melatonin activates several downstream signals, such as nitric oxide (NO), hydrogen peroxide (H2O2), and salicylic acid (SA), which are required for plant Cd tolerance. Similar to the physiological functions of NO, hydrogen sulfide (H2S) is also involved in the abiotic stress-related processes in plants. Moreover, exogenous melatonin induces H2S generation in plants under salinity or heat stress. However, the involvement of H2S action in melatonin-induced Cd tolerance is still largely unknown. In this review, we summarize the progresses in various physiological and molecular mechanisms regulated by melatonin in plants under Cd stress. The complex interactions between melatonin and H2S in acquisition of Cd stress tolerance are also discussed.

Hydrogen peroxide acts downstream of melatonin to induce lateral root formation.

Background and Aims: Although several studies have confirmed the beneficial roles of exogenous melatonin in lateral root (LR) formation, the molecular mechanism is still elusive. Here, the role of hydrogen peroxide (H2O2) in the induction of LR formation triggered by melatonin was investigated. Methods: Alfalfa (Medicago sativa 'Biaogan') and transgenic Arabidopsis seedlings were treated with or without melatonin, diphenyleneiodonium (DPI, NADPH oxidase inhibitor), N,N'-dimethylthiourea (DMTU, H2O2 scavenger), alone or combined. Then, H2O2 content was determined with 2',7'-dichlorofluorescein diacetate (H2DCFDA)-dependent fluorescence and spectrophotography. Transcript levels of cell cycle regulatory genes were analysed by real-time reverse transcription-PCR. Key Results: Application of exogenous melatonin not only increased endogenous H2O2 content but also induced LR formation in alfalfa seedlings. Consistently, melatonin-induced LR primordia exhibited an accelerated response. These inducible responses were significantly blocked when DPI or DMTU was applied. Compared with the wild-type, transgenic Arabidopsis plants overexpressing alfalfa MsSNAT (a melatonin synthesis gene) increased H2O2 accumulation and thereafter LR formation, both of which were blocked by DPI or DMTU. Similarly, melatonin-modulated expression of marker genes responsible for LR formation, including MsCDKB1;1, MsCDKB2;1, AtCDKB1;1 and AtCDKB2;1, was obviously impaired by the removal of H2O2 in both alfalfa and transgenic Arabidopsis plants. Conclusions: Pharmacological and genetic evidence revealed that endogenous melatonin-triggered LR formation was H2O2-dependent.

Cytokinin is involved in TPS22-mediated selenium tolerance in Arabidopsis thaliana.

Background and Aims: Excess selenium (Se) is toxic to plants, but relatively little is known about the regulatory mechanism of plant Se tolerance. This study explored the role of the TPS22 gene in Se tolerance in Arabidopsis thaliana. Methods: Arabidopsis wild type and XVE mutant seeds were grown on half-strength MS media containing Na2SeO3 for screening of the Se-tolerant mutant tps22. The XVE T-DNA-tagged genomic sequence in tps22 was identified by TAIL-PCR. The TPS22 gene was transformed into the mutant tps22 and wild type plants using the flower infiltration method. Wild type, tps22 mutant and transgenic seedlings were cultivated on vertical plates for phenotype analysis, physiological index measurement and gene expression analysis. Key Results: We identified an Arabidopsis Se-tolerant mutant tps22 from the XVE pool lines, and cloned the gene which encodes the terpenoid synthase (TPS22). TPS22 was downregulated by Se stress, and loss-of-function of TPS22 resulted in decreased Se accumulation and enhanced Se tolerance; by contrast, overexpression of TPS22 showed similar traits to the wild type under Se stress. Further analysis revealed that TPS22 mediated Se tolerance through reduction of Se uptake and activation of metabolism detoxification, which decreased transcription of high-affinity transporters PHT1;1, PHT1;8 and PHT1;9 and significantly increased transcription of selenocysteine methyltransferase (SMT), respectively. Moreover, loss-of-function of TPS22 resulted in reduced cytokinin level and repression of cytokinin signalling components AHK3 and AHK4, and upregulation of ARR3, ARR15 and ARR16. Exogenous cytokinin increased transcription of PHT1;1, PHT2;1 and SMT and decreased Se tolerance of the tps22 mutant. In addition, enhanced Se resistance of the tps22 mutant was associated with glutathione (GSH). Conclusions: Se stress downregulated TPS22, which reduced endogenous cytokinin level, and then affected the key factors of Se uptake and metabolism detoxification. This cascade of events resulted in reduced Se accumulation and enhanced Se tolerance.

Methane alleviates alfalfa cadmium toxicity via decreasing cadmium accumulation and reestablishing glutathione homeostasis.

Although methane (CH4) generation triggered by some environmental stimuli, displays the protective response against oxidative stress in plants, whether and how CH4 regulates plant tolerance against cadmium stress is largely unknown. Here, we discovered that cadmium (Cd) stimulated the production of CH4 in alfalfa root tissues. The pretreatment with exogenous CH4 could alleviate seedling growth inhibition. Less amounts of Cd accumulation was also observed. Consistently, in comparison with Cd stress alone, miR159 transcript was down-regulated by CH4, and expression levels of its target gene ABC transporter was increased. By contrast, miR167 transcript was up-regulated, showing a relatively negative correlation with its target gene Nramp6. Meanwhile, Cd-triggered redox imbalance was improved by CH4, evidenced by the reduced lipid peroxidation and hydrogen peroxide accumulation, as well as the induction of representative antioxidant genes. Further results showed that Cd-triggered decrease of the ratio of reduced/oxidized (homo)glutathione was rescued by CH4. Additionally, CH4-triggered alleviation of seedling growth was sensitive to a selective inhibitor of glutathione biosynthesis. Overall, above results revealed that CH4-alleviated Cd accumulation at least partially, required the modulation of heavy metal transporters via miR159 and miR167. Finally, the role of glutathione homeostasis elicited by CH4 was preliminarily suggested.

T cell receptor ß-chain repertoire analysis reveals intratumour heterogeneity of tumour-infiltrating lymphocytes in oesophageal squamous cell carcinoma.

Oesophageal squamous cell carcinoma (ESCC) has a generally poor prognosis, due to the lack of effective treatment methods. Immunotherapeutic approaches based on tumour-infiltrating lymphocytes (TILs) have demonstrated that durable responses are produced in some patients with solid tumours, which suggests the potential feasibility of clinical application of immunotherapy for ESCC. However, many of the basic characteristics of TILs in ESCC are poorly understood, including clonality, specificity and spatial heterogeneity of the response of TILs, which depends on the interaction between antigens and T cell receptors (TCRs). We used ultra-deep sequencing of rearranged genes in TCR ß-chain (TCRß) to profile the basic characteristics of T cells in tumour tissues (four to six regions from each tumour) as well as matched adjacent normal tissue and peripheral blood from seven patients diagnosed with primary ESCC. We found that T cell clones within ESCCs were quite different from those of the peripheral blood and even the adjacent normal tissues in general. Although there was a relatively higher degree of overlap of intratumoural TCRß repertoires than those between the tumour and other tissues, intratumoural TCRß repertoires were spatially heterogeneous. Due to the restricted sampling, high-throughput TCRß sequencing could characterize the diversity and composition of a limited (compartment-dependent) fraction of the respective T cell clones in any individual ESCC, expanding our understanding of immune behaviour and immune response and shedding more light on ESCC immunotherapy. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Loss-of-function mutations in the APX1 gene result in enhanced selenium tolerance in Arabidopsis thaliana.

It is generally recognized that excess selenium (Se) has a negative effect on the growth and development of plants. Numerous studies have identified key genes involved in selenium tolerance in plants; however, our understanding of its molecular mechanisms is far from complete. In this study, we isolated an Arabidopsis selenium-resistant mutant from the mutant XVE pool lines because of its increased root growth and fresh weight in Se stress, and cloned the gene, which encodes the cytosolic ascorbate peroxidase (APX1). Two other APX1 gene knockout allelic lines were also selenium resistant, and the APX1-complementary COM1 restored the growth state of wild type under Se stress. In addition, these APX1 allelic lines accumulated more Se than did wild-type plants when subjected to Se stress. Further analysis revealed that the APX1-mediated Se tolerance was associated, at least in part, with the enhanced activities of antioxidant enzymes catalase, glutathione peroxidase and glutathione reductase. Moreover, enhanced Se resistance of the mutants was associated with glutathione (GSH), which had the higher expression level of GSH1 gene involved in GSH synthesis and consequently increased GSH content. Our results provide genetic evidence indicating that loss-of-function of APX1 results in tolerance to Se stress.

Expression of AIM2 is correlated with increased inflammation in chronic hepatitis B patients.

BACKGROUND: The absent in melanoma 2 (AIM2), a cytosolic dsDNA inflammasome, can be activated by viral DNA to trigger caspase-1. Its role in immunopathology of chronic hepatitis B and C virus (HBV, HCV) infection is still largely unclear. In this study, the expression AIM2, and its downstream cytokines, caspase-1, IL-18 and IL-1ß, in liver tissue of patients with chronic hepatitis B and C (CHB, CHC) were investigated. METHODS: A total of 70 patients diagnosed with chronic hepatitis were enrolled, including 47 patients with CHB and 23 patients with CHC. A liver biopsy was taken from each patient, and immunohistochemistry was used to detect the expression of AIM2 and inflammatory factors caspase-1, IL-18, and IL-1ß in the biopsy specimens. The relationship between AIM2 expression and these inflammatory factors was analyzed. RESULTS: The expression of AIM2 in CHB patients (89.4 %) was significantly higher than in CHC patients (8.7 %), and among the CHB patients, the expression of AIM2 was significantly higher in the high HBV replication group (HBV DNA ≥ 1 × 10(5)copies/mL) than in the low HBV replication group (HBV DNA < 1 × 10(5)copies/mL). The expression of AIM2 was also correlated with HBV-associated inflammatory activity in CHB patients statistically. Additionally, AIM2 levels were positively correlated with the expression of caspase-1, IL-1ß and IL-18 in CHB patients, which implied that the AIM2 expression is directly correlated with the inflammatory activity associated with CHB. CONCLUSIONS: AIM2 upregulation may be a component of HBV immunopathology. The underlying mechanism and possible signal pathway warrant further study.

Genetic polymorphisms of NAMPT related with susceptibility to esophageal squamous cell carcinoma.

BACKGROUND: Nicotinamide phosphoribosyl transferase (Nampt) plays a crucial role in tumorigenesis. The present study examines whether genetic polymorphisms of NAMPT are related to the risk of developing esophageal squamous cell carcinoma (ESCC). METHODS: A total of 810 subjects were enrolled in this study, including 405 ESCC patients and 405 healthy controls. Using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), genotypes at rs61330082, rs2505568 and rs9034 of NAMPT were identified. Haplotypes were constructed using PHASE software. Multivariate logistic regression models were used to evaluate the potentiating effects of the genotypes, alleles and haplotypes on the development of ESCC. RESULTS: The presence of genotypes CT and TT and allele T at rs61330082 was less frequent in ESCC cases than in controls (48.89% vs. 53.33%, P < 0.01, 95% CI: 0.33-0.68; 18.52% vs. 30.37%, P < 0.01, 95% CI: 0.22-0.50; 42.96% vs. 57.04%, P < 0.01, 95% CI: 0.38-0.61; respectively). No statistically significant differences existed in the distributions of genotypes or alleles at rs2505568 or rs9034 between ESCC cases and controls. Of five haplotypes constructed, haplotypes CTC, CTT and CAC were higher in ESCC cases (P < 0.01, OR = 1.57, 95% CI: 1.16-2.12; P = 0.04, OR = 1.72, 95% CI: 1.03-2.85; P < 0.01, OR = 3.39, 95% CI: 1.99-5.75; respectively) than in controls. CONCLUSION: Genetic polymorphisms of NAMPT, specifically genotype CC and allele C at rs61330082 as well as haplotypes CTC, CTT and CAC, were significantly correlated with ESCC susceptibility.

Functional polymorphisms of caveolin-1 variants as potential biomarkers of esophageal squamous cell carcinoma.

OBJECTIVE: To investigate the association of caveolin-1 (CAV1) genetic variants (C239A (rs1997623), G14713A (rs3807987), G21985A (rs12672038), T29107A (rs7804372)) with esophageal squamous cell carcinoma (ESCC) susceptibility. METHODS: A total of 427 patients with ESCC and 427 healthy controls were genotyped using the polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) method. RESULTS: There were significant differences between patients and controls in distributions of their genotypes and allelic frequencies in G14713A and T29107A polymorphisms. Furthermore, haplotype analysis revealed that haplotypes CAAT and CAGT were associated with high risk for ESCC, while haplotype CGGA was protective against ESCC. Stratified analysis showed the associations between the SNPs (G14713A and T29107A) and ESCC risk were noteworthy among female patients and patients who never smoke or drank alcohol. CONCLUSIONS: Genetic polymorphisms of CAV1 G14713A and T29107A might affect an individual's susceptibility in developing ESCC, making them efficient potential genetic biomarkers for early detection of ESCC.

Extraction, Identification, and Antioxidant Activity of Flavonoids from Hylotelephium spectabile (Boreau) H. Ohba.

The extraction of total flavonoids from Hylotelephium spectabile (Boreau) H. Ohba (H. spectabile) leaves was studied through the use of a double enzyme-assisted ultrasonic method, and the extraction process was optimized using the Box-Behnken design. Eight different macroporous resins were screened for purification in single-factorial experiments, and the flavonoid compounds in the extract of H. spectabile leaves were identified using HPLC-MS. Through the evaluation of the total reducing capacity and capacity for reducing 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH), hydroxyl radicals (·OH), and 2,2'-biazobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), the in vitro antioxidant activities of the crude extracts of the total flavonoids and purified total flavonoids of H. spectabile leaves were investigated. The results showed that the most efficient conditions for flavonoid extraction were an ultrasonic extraction time of 60 min, an ethanol concentration of 35%, a liquid-to-material ratio of 20:1 mL/g, and an amount of enzyme (cellulose/pectinase = 1:1) of 1.5%, forming H. spectabile powder. Under these conditions, the total flavonoid extraction rate in the H. spectabile leaf extract was 4.22%. AB-8 resin showed superior performance in terms of purification, and the optimal adsorption and desorption times were 1.5 h and 3 h, respectively. The recommended parameters for purification included a liquid volume of 5.5 BV, a flow rate of 1.2 BV/min, a pH of 5, and a concentration of 0.8 mg/mL. The observed order for reducing capacity was ascorbic acid (VC) > rutin > purified total flavonoids > crude extract of total flavonoids. The purified total flavonoid extract from H. spectabile showed a good scavenging ability against DPPH, ·OH, and ABTS·+, suggesting strong antioxidant activity. Therefore, this study can serve as technical support and reference data for the further development and utilization of H. spectabile resources.

Extraction, Purification, Sulfated Modification, and Biological Activities of Dandelion Root Polysaccharides.

In this study, polysaccharides were extracted at a rate of 87.5% ± 1.5% from native dandelion roots, and the dandelion root polysaccharides (DRPs) were then chemically modified to obtain sulfated polysaccharides (SDRPs) with a degree of substitution of 1.49 ± 0.07. The effects of modification conditions, physicochemical characterizations, structural characteristics, antioxidant properties, hypoglycemic activity, and proliferative effects on probiotics of DRP derivatives were further investigated. Results showed that the optimum conditions for sulfation of DRPs included esterification reagents (concentrated sulfuric acid: n-butanol) ratio of 3:1, a reaction temperature of 0 °C, a reaction time of 1.5 h, and the involvement of 0.154 g of ammonium sulfate. The DRPs and SDRPs were composed of six monosaccharides, including mannose, glucosamine, rhamnose, glucose, galactose, and arabinose. Based on infrared spectra, the peaks of the characteristic absorption bands of S=O and C-O-S appeared at 1263 cm-1 and 836 cm-1. Compared with DRPs, SDRPs had a significantly lower relative molecular mass and a three-stranded helical structure. NMR analysis showed that sulfated modification mainly occurred on the hydroxyl group at C6. SDRPs underwent a chemical shift to higher field strength, with their characteristic signal peaking in the region of 1.00-1.62 ppm. Scanning electron microscopy (SEM) analysis indicated that the surface morphology of SDRPs was significantly changed. The structure of SDRPs was finer and more fragmented than DRPs. Compared with DRPs, SDRPs showed better free radical scavenging ability, higher Fe2+chelating ability, and stronger inhibition of α-glucosidase and α-amylase. In addition, SDRPs had an excellent promotional effect on the growth of Lactobacillus plantarum 10665 and Lactobacillus acidophilus. Therefore, this study could provide a theoretical basis for the development and utilization of DRPs.

Correction: Novel aerosol treatment of airway hyper-reactivity and inflammation in a murine model of asthma with a soluble epoxide hydrolase inhibitor.

[This corrects the article DOI: 10.1371/journal.pone.0266608.].

Temporal bright light at low frequency retards lens-induced myopia in guinea pigs.

Purpose: Bright light conditions are supposed to curb eye growth in animals with experimental myopia. Here we investigated the effects of temporal bright light at very low frequencies exposures on lens-induced myopia (LIM) progression. Methods: Myopia was induced by application of -6.00 D lenses over the right eye of guinea pigs. They were randomly divided into four groups based on exposure to different lighting conditions: constant low illumination (CLI; 300 lux), constant high illumination (CHI; 8,000 lux), very low frequency light (vLFL; 300/8,000 lux, 10 min/c), and low frequency light (LFL; 300/8,000 lux, 20 s/c). Refraction and ocular dimensions were measured per week. Changes in ocular dimensions and refractions were analyzed by paired t-tests, and differences among the groups were analyzed by one-way ANOVA. Results: Significant myopic shifts in refractive error were induced in lens-treated eyes compared with contralateral eyes in all groups after 3 weeks (all P < 0.05). Both CHI and LFL conditions exhibited a significantly less refractive shift of LIM eyes than CLI and vLFL conditions (P < 0.05). However, only LFL conditions showed significantly less overall myopic shift and axial elongation than CLI and vLFL conditions (both P < 0.05). The decrease in refractive error of both eyes correlated significantly with axial elongation in all groups (P < 0.001), except contralateral eyes in the CHI group (P = 0.231). LFL condition significantly slacked lens thickening in the contralateral eyes. Conclusions: Temporal bright light at low temporal frequency (0.05 Hz) appears to effectively inhibit LIM progression. Further research is needed to determine the safety and the potential mechanism of temporal bright light in myopic progression.

Crosstalk between melatonin and reactive oxygen species in fruits and vegetables post-harvest preservation: An update.

Fruits and vegetables contain numerous nutrients, such as vitamins, minerals, phenolic compounds, and dietary fibers. They reduce the incidence of cardiovascular diseases and the risk of certain chronic diseases, and improve the antioxidant and anti-inflammatory capacity. Moreover, melatonin was found in various fruits and vegetables species. Melatonin acts as a multifunctional compound to participate in various physiological processes. In recent years, many advances have been found that melatonin is also appraised as a key modulator on the fruits and vegetables post-harvest preservation. Fruits and vegetables post-harvest usually elicit reactive oxygen species (ROS) generation and accumulation. Excess ROS stimulate cell damage, protein structure destruction, and tissue aging, and thereby reducing their quality. Numerous studies find that exogenous application of melatonin modulates ROS homeostasis by regulating the antioxidant enzymes and non-enzymatic antioxidants systems. Further evidences reveal that melatonin often interacts with hormones and other signaling molecules, such as ROS, nitric oxide (NO), hydrogen sulfide (H2S), and etc. Among these 'new' molecules, crosstalks of melatonin and ROS, especially the H2O2 produced by RBOHs, are provided in fruits and vegetables post-harvest preservation in this review. It will provide reference for complicated integration of both melatonin and ROS as signal molecules in future study.

A Review: Systemic Signaling in the Regulation of Plant Responses to Low N, P and Fe.

Plant signal transduction occurs in response to nutrient element deficiency in plant vascular tissue. Recent works have shown that the vascular tissue is a central regulator in plant growth and development by transporting both essential nutritional and long-distance signaling molecules between different parts of the plant's tissues. Split-root and grafting studies have deciphered the importance of plants' shoots in receiving root-derived nutrient starvation signals from the roots. This review assesses recent studies about vascular tissue, integrating local and systemic long-distance signal transduction and the physiological regulation center. A substantial number of studies have shown that the vascular tissue is a key component of root-derived signal transduction networks and is a regulative center involved in plant elementary nutritional deficiency, including nitrogen (N), phosphate (P), and iron (Fe).