The Effects of Ambient Temperature and Atmospheric Humidity on the Diffusion Dynamics of Hydrogen Fluoride Gas Leakage Based on the Computational Fluid Dynamics Method.

In order to investigate the impact of environmental temperature and atmospheric humidity on the leakage and diffusion of hydrogen fluoride (HF) gas, this study focused on the real scenario of an HF chemical industrial park. Based on the actual dispersion scenario of HF gas, a proportionally scaled-down experimental platform for HF gas leakage was established to validate the accuracy and feasibility of numerical simulations under complex conditions. Using the validated model, the study calculated the complex scenarios of HF leakage and diffusion within the temperature range of 293 K to 313 K and the humidity range of 0% to 100%. The simulation results indicated that different environmental temperatures had a relatively small impact on the hazardous areas (the lethal area, severe injury area, light injury area, and maximum allowable concentration (MAC) area) formed by HF gas leakage. At 600 s of dispersion, the fluctuation range of hazardous area sizes under different temperature conditions was between 3.11% and 13.07%. In contrast to environmental temperature, atmospheric relative humidity had a more significant impact on the dispersion trend of HF leakage. Different relative humidity levels mainly affected the areas of the lethal zone, light injury zone, and MAC zone. When HF continued to leak and disperse for 600 s, compared to 0% relative humidity, 100% relative humidity reduced the lethal area by 35.7%, while increasing the light injury area and MAC area by 27.26% and 111.6%, respectively. The impact on the severe injury area was relatively small, decreasing by 1.68%. The results of this study are crucial for understanding the dispersion patterns of HF gas under different temperature and humidity conditions.

Exploring the role of Maillard reaction and lipid oxidation in the advanced glycation end products of batter-coated meat products during frying.

The Maillard reaction occurs during the frying of batter-coated meat products, resulting in the production of advanced glycosylation products that are harmful to human health. This study investigated the effects of frying temperature (140, 150, 160, 170 and 180 ℃) and time (80, 100, 120, 140 and 160 s) on the quality, advanced glycation end product (AGE) level and the relationship between these parameters in batter-coated meat products were investigated. The results showed that with an increase in frying temperature and time, the moisture content of the batter-coated meat products gradually decreased, the thiobarbituric Acid Reactive Substance (TBARS) values and oil content increased to 0.37 and 21.7 %, respectively, and then decreased, and CML and CEL content increased to 7.30 and 4.86 mg/g, respectively. Correlation analysis showed that the moisture content and absorbance at 420 nm, as well as TBARS values, were highly correlated with the oil content in batter-coated meat products. Additionally, the absorbance at 420 nm and TBARS levels were significantly correlated with AGE levels. Moreover, the AGE content in batter-coated meat products was less variable at lower frying temperatures or shorter frying times, and the influence of temperature on AGE formation was greater than that of time. Overall, these findings may help to better control the cooking conditions of batter-coated meat products based on AGE profiles.

A case report of the treatment and care of decubitus ulcers in macaques with spinal cord injury.

Decubitus ulcers are a common spinal cord injury (SCI) complication that puts patients' lives in danger and has emerged as a more prevalent issue in modern clinical rehabilitation and care. Decubitus ulcers in humans can currently be treated in a number of different ways, but there are fewer studies on how to treat and care for decubitus ulcers in macaques. To treat a 20-year-old adult male macaque monkey with SCI and decubitus ulcers after a quarter transection of the thoracic spinal cord, a number of scientific care procedures and pharmaceutical treatments, such as dietary changes and topical or intravenous administration of medication, were carried out and continuously monitored in real-time. In comparison to the untreated group, we observed a significant improvement in decubitus wound healing in the macaques. In this article, we provide a good protocol for decubitus ulcer care after SCI and suggest that future experimental animal modeling needs to focus on issues such as care for postoperative complications.

Cloudy or sunny? Effects of different environmental types of urban green spaces on public physiological and psychological health under two weather conditions.

Numerous studies have demonstrated that urban green spaces (UGSs) benefit human health, but few have focused on the influence of weather on environmental restorativeness. This study assessed how different weather conditions and environments affect human health. We exposed 50 participants to different UGS environments under cloudy and sunny conditions and collected physiological, psychological and aesthetic preference data. The result showed that the physical and mental benefits of UGSs were stronger on sunny days (pulse: [t = 2.169, p < 0.05]; positive affect: [Z = -10.299, p < 0.001]; perceived restortiveness: [Z = -3.224, p < 0.01]). The spaces with exposed sky had greater physiological restorativeness on sunny days; the spaces with calm water had greater emotional restorativeness on cloudy days, and natural spaces with less sky exposure had greater perceived restoration in both weather conditions. The spaces with water and less sky exposure promoted psychophysiological restoration in both weather conditions. This study demonstrates that weather significantly influences the restorative potential of UGSs, and there are also restorative variations in different green space environments under two weather conditions. In future UGS planning practices, it would be advisable to select appropriate environmental types and features based on the climatic characteristics of different regions. For instance, in areas with frequent overcast conditions, incorporating serene water bodies could be advantageous, while regions with predominantly sunny weather should encompass spaces with expansive sky views. By conducting comprehensive research on restoration environments that take weather conditions into account, new insights and nature-based solutions can be provided for creating healthy human habitats in the context of global climate change.

Effects of Different Bacteriostats on the Dynamic Germination of Clostridium perfringens Spores.

Bacteriostats, as chemical substances that inhibit bacterial growth, are widely used in the sterilization process; however, their effects on spindle spores are unclear. In this study, the effects of bacteriostats, including nine commonly used food additives and four detergents, on the growth of Clostridium perfringens spores were investigated. The results showed that 0.07‱ ethylenediaminetetraacetate had a good inhibitory effect on C. perfringens spore growth, and the spore turbidity decreased by 4.8% after incubation for 60 min. Furthermore, 0.3‱ tea polyphenols, 0.8‱ D-isoascorbic acid, and 0.75‱ potassium sorbate promoted leakage of contents during spore germination. Among the four detergents, 5‱ glutaraldehyde solution presented the best inhibitory effect on the growth of C. perfringens spores, and the spore turbidity decreased by 5.6% after incubation for 60 min. Further analysis of the inactivation mechanism of spores by the bacteriostats was performed by comparing the leakage of UV-absorbing substances during germination. The results revealed that bacteriostats could not directly kill the spores, but could inactivate them by inhibiting germination or damaging the spore structure during germination, thus preventing the formation of bacterial vegetative bodies. These findings provide important information and reference for the mechanism underlying the effects of different bacteriostatic agents on spore growth.

Effects of mowing on Pb accumulation and transport in Cynodon dactylon (L.) Pers.

Bermudagrass is a perennial herb with the potential to remediate Pb pollution in soils, and it has mechanical resistance to shearing. However, the effects of mowing on Pb absorption and accumulation in bermudagrass are still unclear. In this study, we investigated the effects of different quantities (0, 1, 2, 4 applications) of mowing treatments under 200 mg L-1 Pb application on Pb accumulation and transport in bermudagrass and explored the related mechanisms. Compared to the Pb treatment, all of the mowing treatments greatly decreased root Pb concentration/accumulation, significantly enhanced Pb concentrations/accumulations in stubble stems and stubble leaves, and ultimately promoted Pb enrichment and transport. Of the treatments in this study, two applications of mowing best promoted Pb enrichment, and four applications of mowing best promoted Pb transport efficiency. Furthermore, mowing mediated the microdistribution and physiological patterns of Pb in bermudagrass and affected the Pb transport by changing the subcellar distribution patterns and chemical forms of Pb in various tissues. Additionally, mowing promoted the transport of all mineral elements and showed a synergistic relationship with Pb absorption and transport. The change in mineral element metabolism patterns may be an important reason why mowing promoted Pb accumulation in bermudagrass. Our study provides the first comprehensive evidence regarding mowing facilitating the absorption, accumulation and transport of Pb in bermudagrass. Moderate mowing may be an effective strategy to assist in soil Pb remediation using bermudagrass.

Low-molecular-weight organic acid-mediated tolerance and Pb accumulation in centipedegrass under Pb stress.

Lead (Pb) is one of the most harmful, toxic pollutants to the ecological environment and humans. Centipedegrass, a fast-growing warm-season turfgrass, is excellent for Pb pollution remediation. Exogenous low-molecular-weight organic acid (LMWOA) treatment is a promising approach for assisted phytoremediation. However, the effects of this treatment on the tolerance and Pb accumulation of centipedegrass are unclear. This study investigated these effects on the physiological growth response and Pb accumulation distribution characteristics of centipedegrass. Applications of 400 µM citric acid (CA), malic acid (MA) and tartaric acid (TA) significantly reduced membrane lipid peroxidation levels of leaves and improved biomass production of Pb-stressed plants. These treatments mainly increased peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) activities and enhanced free protein (Pro), ascorbic acid (AsA) and phytochelatins (PCs) contents, ultimately improving the Pb tolerance of centipedegrass. Their promoting effects decreased as follows: TA>CA>MA. All the treatments decreased root Pb concentrations and increased stem and leaf Pb concentrations, thus increasing total Pb accumulation and TF values. MA had the best and worst effects on Pb accumulation and Pb transportation, respectively. CA had the best and worst effects on Pb transportation and Pb accumulation, respectively. TA exhibited strong effects on both Pb accumulation and transport. Furthermore, all treatments changed the subcellular Pb distribution patterns and distribution models of the chemical forms of Pb in each tissue. The root Pb concentration was more highly correlated with the Pb subcellular fraction distribution pattern, while the stem and leaf Pb concentrations were more highly correlated with the distribution models of the chemical forms of Pb. Overall, TA improved plant Pb tolerance best and promoted both Pb absorption and transportation well and is considered the best candidate for Pb-contaminated soil remediation with centipedegrass. This study provides a new idea for Pb-contaminated soil remediation with centipedegrass combined with LMWOAs.

Multiple Technologies Combined to Analyze the Changes of Odor and Taste in Daokou Braised Chicken during Processing.

This study analyzed the changes of odor and taste in Daokou braised chicken during processing by GC-MS, GC-IMS, e-nose and e-tongue. The 75 and 55 volatile compounds identified in Daokou braised chicken by GC-MS and GC-IMS, respectively, included hydrocarbons, aldehydes, alcohols, terpenes, ketones, heterocyclics, esters, acids and phenols; among them, aldehydes, alcohols and ketones were the most abundant. The number and proportion of volatile compounds in Daokou braised chicken changed significantly (p < 0.05) in the process. The proportion of volatile compounds with animal fatty odor, such as aldehydes and alcohols, decreased, while that of esters, ketones and terpenes from spices with fruity fragrance increased, especially in the braising stage. An e-nose showed that the odor intensities of sulfur-containing and nitrogen oxide compounds were higher (p < 0.05) after the braising stage, but weakened after 2 h braising. An e-tongue showed that saltiness and richness increased significantly (p < 0.05) after braising. The results of these four techniques showed that braising promoted the release of flavor compounds, and was beneficial to salt penetration and umami release. However, long braising could lead to weakened flavor intensity and the introduction of bitterness and astringency. This study also found that GC-IMS and e-nose were more sensitive to trace compounds such as sulfur-containing and nitrogen oxide compounds, esters, acids and phenolics in Daokou braised chicken than GC-MS. The use of multiple technologies could provide more comprehensive flavor profiles for Daokou braised chicken during processing. This study provides insights into the control of flavor of Daokou braised chicken, and may be of practical relevance for the poultry industry.

The highly continuous reference genome of a leaf-chimeric red pineapple (Ananas comosus var. bracteatus f. tricolor) provides insights into elaboration of leaf color.

Ananas comosus var. bracteatus f. tricolor (GL1) is a red pineapple accession whose mostly green leaves with chimeric white leaf margins turn red in spring and autumn and during flowering. It is an important ornamental plant and ideal plant research model for anthocyanin metabolism, chimeric leaf development, and photosynthesis. Here, we generated a highly contiguous chromosome-scale genome assembly for GL1 and compared it with other 3 published pineapple assemblies (var. comosus accessions MD2 and F153, and var. bracteatus accession CB5). The GL1 assembly has a total size of ∼461 Mb, with a contig N50 of ∼2.97 Mb and Benchmarking Universal Single-Copy Ortholog score of 97.3%. More than 99% of the contigs are anchored to 25 pseudochromosomes. Compared with the other 3 published pineapple assemblies, the GL1 assembly was confirmed to be more continuous. Our evolutionary analysis showed that the Bromeliaceae and Poaceae diverged from their nearest common ancestor ∼82.36 million years ago (MYA). Population structure analysis showed that while GL1 has not undergone admixture, bracteatus accession CB5 has resulted from admixture of 3 species of Ananas. Through classification of orthogroups, analysis of genes under positive selection, and analysis of presence/absence variants, we identified a series of genes related to anthocyanin metabolism and development of chimeric leaves. The structure and evolution of these genes were compared among the published pineapple assemblies with reveal candidate genes for these traits. The GL1 genome assembly and its comparisons with other 3 pineapple genome assemblies provide a valuable resource for the genetic improvement of pineapple and serve as a model for understanding the genomic basis of important traits in different pineapple varieties and other pan-cereal crops.

Nutritional Management of Children With Neurological Impairment in China: Current Status and Future Directions.

The aim of this study is to assess the awareness of Chinese physicians on gastrointestinal and nutritional management of children with neurological impairment (NI) and to assess the practical application of the European Society of Pediatric Gastroenterology, Hepatology, and Nutrition guidelines on the management of nutritional and gastrointestinal problems in children with NI in Asian countries, particularly in several major medical centers in China. Methods: A web-based questionnaire was distributed between November 2020 and January 2021 among Chinese healthcare professionals involved in the clinical management of children with NI. Fifteen questions covering the most relevant aspects of nutritional management and gastrointestinal issues of children with NI were surveyed. A descriptive analysis of responses was performed. Results: A total of 577 healthcare professionals from over 28 provinces in China answered the questionnaire. Anthropometrics were the most used parameters (n = 539) to assess nutritional status. Most respondents (n = 455) indicated weight faltering and/or failure to thrive as definition of undernutrition. Direct observation of meals was considered the recommended method for diagnosing oropharyngeal dysfunction by 542 professionals. Fundoplication was indicated at the time of gastrostomy placement in patients with uncontrolled gastroesophageal reflux disease by 437 respondents. Conclusions: The clinical practice of Chinese healthcare professionals does not completely match the European Society of Pediatric Gastroenterology, Hepatology, and Nutrition guidelines, probably due to the medical system and the economic, social, and cultural differences. Further studies are needed to improve clinical practice and knowledge. Multidisciplinary approach is crucial to optimize the overall medical care and quality of life for children with NI.

NTA-assisted mineral element and lead transportation in Eremochloa ophiuroides (Munro) Hack.

Lead (Pb) is one of the most toxic and harmful pollutants to the environment and human health. Centipedegrass (Eremochloa ophiuroides (Munro) Hack.), an excellent ground cover plant for urban plant communities, exhibits the outstanding lead tolerance and accumulation. Nitrilotriacetic acid (NTA) is an environmentally friendly chelating agent that strengthens phytoremediation. This study explored the effects of different NTA concentrations on the absorption and transportation of mineral elements and Pb in centipedegrass. Following exposure to Pb (500 µM) for 7 days in hydroponic nutrient solution, NTA increased root Mg, K, and Ca concentrations and shoot Fe, Cu, and Mg concentrations and significantly enhanced the translocation factors of mineral elements to the shoot. Although NTA notably decreased root Pb absorption and accumulation, it significantly enhanced Pb translocation factors, and the Pb TF value was the highest in the 2.0 mM NTA treatment. Furthermore, the shoot translocation of Pb and mineral elements was synergistic. NTA can support mineral element homeostasis and improve Pb translocation efficiency in centipedegrass. Regarding root radial transport, NTA (2.0 mM) significantly promoted Pb transport by the symplastic pathway under the treatments with low-temperature and metabolic inhibitors. Meanwhile, NTA increased apoplastic Pb transport at medium and high Pb concentrations (200-800 µM). NTA also enhanced the Pb radial transport efficiency in roots and thus assisted Pb translocation. The results of this study elucidate the effects of NTA on the absorption and transportation of mineral elements and Pb in plants and provide a theoretical basis for the practical application of the biodegradable chelating agent NTA in soil Pb remediation.

Dynamic study of the lead (Pb) tolerance and accumulation characteristics of new dwarf bamboo in Pb-contaminated soil.

Dwarf bamboo is a woody plant with potential for use in the remediation of Pb-contaminated soil. Due to its clonal growth habit, there are two keys to its application for continuous soil Pb remediation: 1) its ability to form shoots and grow into new bamboo normally under Pb stress and 2) the Pb tolerance and accumulation characteristics of this new bamboo. Here, 5 species of dwarf bamboo were treated with 2 levels of soil Pb stress (0 and 1500 mg kg-1). In the roots of 3 of the species (Sasa argenteostriata, Sasaella glabra, and Indocalamus decorus), Pb tended to be distributed along the cell wall and transported to vacuoles. In the other 2 species (Sasa auricoma and Sasa fortunei), Pb was arranged linearly along the cell wall. Under Pb treatment, the new bamboo of all species showed gradual physiological adaptation to Pb stress. Correlations of the net photosynthetic rate, superoxide dismutase activity, and free proline levels with Pb content in new leaves in November were all higher than those in July, though that of malondialdehyde content decreased, suggesting that new dwarf bamboo exhibits good soil Pb stress tolerance. Sasa argenteostriata and Indocalamus decorus consistently maintained higher antioxidant enzyme activities and free proline levels than the other species under Pb treatment, and the total biomass per pot of the new bamboo decreased the least compared to that in the Pb-free treatment for these two species. Therefore, these bamboo species may be used in the long-term continuous remediation of Pb-contaminated soil.

Metabolome and transcriptome profiling reveals anthocyanin contents and anthocyanin-related genes of chimeric leaves in Ananas comosus var. bracteatus.

BACKGROUND: Ananas comosus var. bracteatus is a colorful plant used as a cut flower or landscape ornamental. The unique foliage color of this plant includes both green and red leaves and, as a trait of interest, deserves investigation. In order to explore the pigments behind the red section of the chimeric leaves, the green and red parts of chimeric leaves of Ananas comosus var. bracteatus were sampled and analyzed at phenotypic, cellular and molecular levels in this study. RESULTS: The CIELAB results indicated that the a* values and L* values samples had significant differences between two parts. Freehand sections showed that anthocyanin presented limited accumulation in the green leaf tissues but obviously accumulation in the epidermal cells of red tissues. Transcriptomic and metabolomic analyses were performed by RNA-seq and LC-ESI-MS/MS. Among the 508 identified metabolites, 10 kinds of anthocyanins were detected, with 6 significantly different between the two samples. The cyanidin-3,5-O-diglucoside content that accounts for nearly 95.6% in red samples was significantly higher than green samples. RNA-Seq analyses showed that 11 out of 40 anthocyanin-related genes were differentially expressed between the green and red samples. Transcriptome and metabolome correlations were determined by nine quadrant analyses, and 9 anthocyanin-related genes, including MYB5 and MYB82, were correlated with 7 anthocyanin-related metabolites in the third quadrant in which genes and metabolites showing consistent change. Particularly, the PCCs between these two MYB genes and cyanidin-3,5-O-diglucoside were above 0.95. CONCLUSION: Phenotypic colors are closely related to the tissue structures of different leaf parts of Ananas comosus var. bracteatus, and two MYB transcription factors might contribute to differences of anthocyanin accumulation in two parts of Ananas comosus var. bracteatus chimeric leaves. This study lay a foundation for further researches on functions of MYBs in Ananas comosus var. bracteatus and provides new insights to anthocyanin accumulation in different parts of chimeric leaves.

Melatonin-assisted phytoremediation of Pb-contaminated soil using bermudagrass.

Exogenous application of melatonin to plants is a promising approach for assisted phytoremediation of soil lead (Pb). In this study, we investigated the effects of foliar applications of melatonin to mature bermudagrass (Cynodon dactylon (L.) Pers.), a fast-growing perennial with potential as a non-hyperaccumulator plant for Pb phytoremediation. Following exposure to Pb (3000 mg kg-1) for 30 days, decreases in biomass and chlorophyll production, degradation of thylakoid membranes, reduced photosynthesis and PSII (reaction center of photosystem II) efficiency, and elevated oxidative stress were found. Foliar applications of melatonin to Pb-stressed bermudagrass mitigated these negative effects, restoring photosynthetic pigments and chloroplast ultrastructure, subsequently improving photosynthesis and photochemistry efficiency of PSII. Exogenous melatonin also eliminated the excessive accumulations of reactive oxygen species (ROS) and methylglyoxal (MG) which associated with cellular redox homeostasis by improving ascorbic acid (AsA) and reduced glutathione (GSH) contents, redox status of GSH/GSSG (oxidative glutathione), and key enzymes activities in both AsA-GSH and glyoxalase systems. Ultimately, treating bermudagrass plants with exogenous melatonin elevated biomass production and disproportionally greater Pb translocation to roots and senescent leaves. This collectively resulted in 21% greater recovery of Pb compared to Pb-stressed bermudagrass lacking melatonin application. Overall, results from this study demonstrated the beneficial roles of melatonin for improving the effectiveness of bermudagrass as a non-hyperaccumulator plant for soil Pb phytoremediation.

Effect of Fragrant Primula Flowers on Physiology and Psychology in Female College Students: An Empirical Study.

Indoor plants can positively impact physical and mental health in daily life. However, the benefits of viewing indoor plants may be enhanced if the plants emit a fragrant aroma. In this crossover-design study, we measured the physiological and psychological effects of fragrant and non-fragrant Primula plants on 50 female college students, and explored whether aroma stimulation had additive benefits for this group. Non-fragrant Primula malacoides Franch was used as a control stimulus, and Primula forbesii Franch, which has a floral fragrance, was used as an experimental stimulus. We measured blood pressure, pulse rate, and electroencephalogram (EEG) to evaluate physiological responses, and used a mood state profile and the semantic differential (SD) method to evaluate psychological responses. We found that mean blood pressure and pulse rate decreased significantly after the experiment in both conditions. EEGs showed that the mean values of high alpha waves, high beta waves, and relaxation scores were significantly higher in the experimental vs. control condition. The average scores on each subscale of the psychological questionnaire improved after the experiment in both conditions, and the vitality (V) subscale and total emotional state scores were significantly better in the experimental vs. control condition. The results of the SD method showed that the sense of relaxation and comfort were significantly higher in the experimental vs. control condition. Compared with the non-fragrant Primula, the fragrant Primula induced relatively better physiological and psychological effects.

MfbHLH38, a Myrothamnus flabellifolia bHLH transcription factor, confers tolerance to drought and salinity stresses in Arabidopsis.

BACKGROUND: The basic helix-loop-helix (bHLH) proteins, a large transcription factors family, are involved in plant growth and development, and defensive response to various environmental stresses. The resurrection plant Myrothamnus flabellifolia is known for its extremely strong drought tolerance, but few bHLHs taking part in abiotic stress response have been unveiled in M. flabellifolia. RESULTS: In the present research, we cloned and characterized a dehydration-inducible gene, MfbHLH38, from M. flabellifolia. The MfbHLH38 protein is localized in the nucleus, where it may act as a transcription factor. Heterologous expression of MfbHLH38 in Arabidopsis improved the tolerance to drought and salinity stresses, as determined by the studies on physiological indexes, such as contents of chlorophyll, malondialdehyde (MDA), proline (Pro), soluble protein, and soluble sugar, water loss rate of detached leaves, reactive oxygen species (ROS) accumulation, as well as antioxidant enzyme activities. Besides, MfbHLH38 overexpression increased the sensitivity of stomatal closure to mannitol and abscisic acid (ABA), improved ABA level under drought stress, and elevated the expression of genes associated with ABA biosynthesis and ABA responding, sucha as NCED3, P5CS, and RD29A. CONCLUSIONS: Our results presented evidence that MfbHLH38 enhanced tolerance to drought and salinity stresses in Arabidopsis through increasing water retention ability, regulating osmotic balance, decreasing stress-induced oxidation damage, and possibly participated in ABA-dependent stress-responding pathway.

Systematic identification and comparative analysis of lysine succinylation between the green and white parts of chimeric leaves of Ananas comosus var. bracteatus.

BACKGROUND: Lysine succinylation, an important protein posttranslational modification (PTM), is widespread and conservative. The regulatory functions of succinylation in leaf color has been reported. The chimeric leaves of Ananas comosus var. bracteatus are composed of normal green parts and albino white parts. However, the extent and function of lysine succinylation in chimeric leaves of Ananas comosus var. bracteatus has yet to be investigated. RESULTS: Compared to the green (Gr) parts, the global succinylation level was increased in the white (Wh) parts of chimeric leaves according to the Western blot and immunohistochemistry analysis. Furthermore, we quantitated the change in the succinylation profiles between the Wh and Gr parts of chimeric leaves using label-free LFQ intensity. In total, 855 succinylated sites in 335 proteins were identified, and 593 succinylated sites in 237 proteins were quantified. Compared to the Gr parts, 232 (61.1%) sites in 128 proteins were quantified as upregulated targets, and 148 (38.9%) sites in 70 proteins were quantified as downregulated targets in the Wh parts of chimeric leaves using a 1.5-fold threshold (P < 0.05). These proteins with altered succinylation level were mainly involved in crassulacean acid metabolism (CAM) photosynthesis, photorespiration, glycolysis, the citric acid cycle (CAC) and pyruvate metabolism. CONCLUSIONS: Our results suggested that the changed succinylation level in proteins might function in the main energy metabolism pathways-photosynthesis and respiration. Succinylation might provide a significant effect in the growth of chimeric leaves and the relationship between the Wh and Gr parts of chimeric leaves. This study not only provided a basis for further characterization on the function of succinylated proteins in chimeric leaves of Ananas comosus var. bracteatus but also provided a new insight into molecular breeding for leaf color chimera.

Effect of 24-epibrassinolide on reactive oxygen species and antioxidative defense systems in tall fescue plants under lead stress.

Lead is one of the most hazardous pollutants to both the environment as well as human beings. As one of the approaches to enhance phytoremediation, brassinosteroids are predicted as a potential candidate phytohormone for assisted phytoremediation. Few studies have focused on the physiological regulations of tall fescue plants (Festuca arundinacea Schreb.), a potential phytoremediation species, for its responses to applications of brassinosteroids under lead stress. Therefore, the objectives of this study were to investigate the effects of foliar application of 24-epibrassinolide, a brassinosteroids analogue, on reactive oxygen species accumulation and antioxidative defense systems of tall fescue when exposed to lead, and ultimately its potential to be used in phytoremediation. When exposed to lead (1000 mg/kg) for 80 d, decreases in shoot and root biomass of tall fescue biomass as well as chlorophyll and carotenoid productions were found. Foliar application of 24-epibrassinolide at three rates and five applications every 7 d improved the biomass of both shoots and roots, and increased the photosynthetic pigments. The improved lead tolerance in tall fescue plants after 24-epibrassinolide applications was associated with reduced H2O2 and O2.- accumulations and increased antioxidative enzyme activities including superoxide dismutase, catalase, and guaiacol peroxidase. Additionally, osmoprotectants increased and lipid peroxidation decreased. Ultimately, foliar applications of 24-epibrassinolide enhanced the lead recovery rate of tall fescue plants, proving its potential role in phytoremediation for soil contaminated with heavy metals such as lead.

Screening and characterization of long noncoding RNAs involved in the albinism of Ananas comosus var. bracteatus leaves.

Long noncoding RNAs (lncRNAs) have been reported to play key regulatory roles in plant growth, development, and biotic and abiotic stress physiology. Revealing the mechanism of lncRNA regulation in the albino portions of leaves is important for understanding the development of chimeric leaves in Ananas comosus var. bracteatus. In this study, a total of 3,543 candidate lncRNAs were identified, among which 1,451 were differentially expressed between completely green (CGr) and completely white (CWh) leaves. LncRNAs tend to have shorter transcripts, lower expression levels, and greater expression specificity than protein-coding genes. Predicted lncRNA targets were functionally annotated by the Gene Ontology (GO), Clusters of Orthologous Groups (COG) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. A lncRNA-mRNA interaction network was constructed, and 36 target mRNAs related to chlorophyll metabolism were predicted to interact with 86 lncRNAs. Among these, 25 significantly differentially expressed lncRNAs putatively interacted with 16 target mRNAs. Based on an expression pattern analysis of the lncRNAs and their target mRNAs, the lncRNAs targeting magnesium chelatase subunit H (ChlH), protochlorophyllide oxidoreductase (POR), and heme o synthase (COX10) were suggested as key regulators of chlorophyll metabolism. This study provides the first lncRNA database for A. comosus var. bracteatus and contributes greatly to understanding the mechanism of epigenetic regulation of leaf albinism.

Comparative transcriptomic and proteomic analyses of the green and white parts of chimeric leaves in Ananas comosus var. bracteatus.

BACKGROUND: Ananas comosus var. bracteatus has high ornamental value due to its chimeric leaves. However, the chimeric trait is very unstable in red pineapple plants, and transcriptional variation between the two types of cells (white/green cells) and the molecular mechanism responsible for their albino phenotype remain poorly understood. METHODS: Comparative transcriptomic and proteomic analyses of the white parts (Whs) and green parts (Grs) of chimeric leaves were performed. RESULTS: In total, 1,685 differentially expressed genes (DEGs) (712 upregulated and 973 downregulated) and 1,813 differentially abundant proteins (DAPs) (1,018 with low abundance and 795 with high abundance) were identified. Based on Gene Ontology (Go) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses, the DEGs were mostly involved in carbon fixation in photosynthetic organisms, porphyrin and chlorophyll metabolism and oxidative phosphorylation, while proteomic analysis revealed that DAPs were mostly related to ribosomes, photosynthesis, photosynthesis antennas, and porphyrin and chlorophyll metabolism. Combined analysis showed increased mRNA levels but low abundance of nine proteins level in Whs /Grs related to photosynthetic pigment and photosynthesis. Transcriptional changes, posttranscriptional regulation and translational alterations of key enzymes involved in chlorophyll biosynthesis and photosynthesis may play important roles in the albino parts of chimeric leaves.