The Fungal Diversity and Potential Pathogens Associated with Postharvest Fruit Rot of 'Huangguan' Pear (Pyrus bretschneideri) in Hebei Province, China.

Postharvest fruit rot caused by pathogens is a serious problem in the pear industry. This study investigated the fungal diversity and main pathogens and identified a new pathogen in the stored 'Huangguan' pear (Pyrus bretschneideri Rehd.), the dominant pear variety in northern China. We sampled 20 refrigeration houses from five main producing regions in Hebei Province and used Illumina sequencing technology to detect the fungal composition. Alternaria (56.3%) was the most abundant fungus, followed by Penicillium (9.2%) and Monilinia (6.2%). We also isolated and identified nine strains of Alternaria and four strains of Penicillium. Moreover, we observed a new postharvest fruit disease in 'Huangguan' pear caused by Stemphylium eturmiunum, which was confirmed by phylogenetic analysis by combining the sequences of three conserved genes, including internal transcribed spacer, gapdh, and calmodulin. This study marks the first documentation of S. eturmiunum causing fruit rot in 'Huangguan' pears, offering valuable insights for identifying and controlling this newly identified postharvest disease.

Protein-sparing effects of lipids in the diet of golden pompano (Trachinotus ovatus): evaluation of growth, feed utilization, and lipid metabolism.

To investigate the influences of dietary protein and lipid levels on the growth, feed utilization, morphometric parameters, body composition, serum biochemical parameters, and lipid metabolism of golden pompano (Trachinotus ovatus), nine test diets containing three protein levels (35%, 40%, and 45%) and three lipid levels (8%, 13%, and 18%) were designed in the present study. Each diet (named D1-D9) was randomly assigned to feed triplicate groups of golden pompano juvenile (initial weight ~ 70 g) for 50 days. The results showed that the dietary lipid levels positively correlated with weight gain, specific growth rate, and protein efficiency ratio (PER), suggesting that the high lipid diets (18%) can be efficiently utilized in this fish species. The dietary protein levels have no significant influences on the growth and feed utilization except for the PER. Increasing dietary protein levels resulted in a decrease in hepatosomatic index (HSI), viscerosomatic index (VSI), and intestinal somatic index (ISI), while the dietary lipid level did not have a significant impact on morphological indices except for ISI. The dietary protein and lipid levels had no significant influences on the contents of crude lipid, crude ash, and moisture of whole body, while the crude protein contents was significantly affected by the dietary protein levels. Serum biochemical indexes, including cholesterol (CHO), triglycerides (TG), high-density lipoprotein cholesterol (HDL), and low-density lipoprotein cholesterol (LDL), as well as HDL/LDL ratio were significantly affected by the dietary lipid levels, but not by the dietary protein levels. The expression levels of genes and their associated proteins involved in hepatic lipogenesis (Srebp-1c and Fas) and fatty acids ß-oxidation (Pparα and Cpt-1) were up-regulated with increasing dietary lipid levels, while the former was up-regulated, and the latter was down-regulated with increasing dietary protein levels. Considering the present results in terms of growth performance, feed utilization, morphometric parameters, and lipid metabolism, the recommended dietary protein and lipid levels for golden pompano are 40% and 18%, respectively. The findings suggested that this species exhibits a significant protein-sparing effect on lipid utilization.

Sodium oxamate reduces lactate production to improve the glucose homeostasis of Micropterus salmoides fed high-carbohydrate diets.

The study was performed to evaluate the effects of the reduced lactate production by sodium oxamate (SO) on growth performance, lactate and glucose and lipid metabolism, and glucose tolerance of Micropterus salmoides fed high-carbohydrate (CHO) diets. In in vitro study, primary hepatocytes were incubated for 48 h in a control medium (5.5 mM glucose), a high-glucose medium (25 mM glucose, HG), or a SO-containing high-glucose medium (25 mM glucose + 50 mM SO, HG-SO). Results indicated lactate and triglyceride (TG) levels, and lactate dehydrogenase a (LDH-a) expression in the HG-SO group were remarkably lower than those of the HG group. In in vivo study, M. salmoides (5.23 ± 0.03 g) were fed four diets containing a control diet (10% CHO, C) and three SO contents [0 (HC), 100 (HC-SO1), and 200 (HC-SO2) mg·kg-1, respectively] of high-CHO diets (20% CHO) for 11 wk. High-CHO diets significantly reduced weight gain rate (WGR), specific growth rate (SGR), p-AMPK-to-t-AMPK ratio, and expression of insulin receptor substrate 1 (IRS1), insulin-like growth factor I (IGF-I), insulin-like growth factor I receptor (IGF-IR), fructose-1,6-biphosphatase (FBPase), peroxisome proliferator-activated receptor α (PPARα), and carnitine palmitoyl transferase 1α (CPT1α) compared with the C group, whereas the opposite was true for plasma levels of glucose, TG, lactate, tissue glycogen, and lipid contents, and expression of LDH-a, monocarboxylate transporter 1 and 4 (MCT1 and MCT4), insulin, glucokinase (GK), pyruvate dehydrogenase E1 subunit (PDH), sterol-regulatory element-binding protein 1 (SREBP1), fatty acid synthase (FAS). The HC-SO2 diets remarkably increased WGR, SGR, p-AMPK-to-t-AMPK ratio, and expression of IRS1, IGF-I, IGF-IR, GK, PDHα, PDHß, FAS, acetyl-CoA carboxylase 1 (ACC1), PPARα, and CPT1α compared with the HC group. Besides, HC-SO2 diets also enhanced glucose tolerance of fish after a glucose loading. Overall, the reduced lactate production by SO benefits growth performance and glucose homeostasis of high-CHO-fed M. salmoides through the enhancement of glycolysis, lipogenesis, and fatty acid ß-oxidation coupled with the suppression of glycogenesis and gluconeogenesis.

Time-Series Transcriptome Analysis Reveals the Molecular Mechanism of Ethylene Reducing Cold Sensitivity of Postharvest 'Huangguan' Pear.

'Huangguan' pear (Pyrus bretschneideri Rehd) fruit is susceptible to cold, characterized by developing peel browning spots (PBS) during cold storage. Additionally, ethylene pretreatment reduces chilling injury (CI) and inhibits PBS occurrence, but the mechanism of CI remains unclear. Here, we deciphered the dynamic transcriptional changes during the PBS occurrence with and without ethylene pretreatment via time-series transcriptome. We found that ethylene suppressed the cold-signaling gene expression, thereby decreasing the cold sensitivity of the 'Huangguan' fruit. Moreover, the "Yellow" module closely correlated with PBS occurrence was identified via weighted gene co-expression network analysis (WGCNA), and this module was related to plant defense via Gene Ontology (GO) enrichment analysis. Local motif enrichment analysis suggested that the "Yellow" module genes were regulated by ERF and WRKY transcription factors. Functional studies demonstrated that PbWRKY31 has a conserved WRKY domain, lacks transactivation activity, and localizes in the nucleus. PbWRKY31-overexpressed Arabidopsis were hypersensitive to cold, with higher expression levels of cold signaling and defense genes, suggesting that PbWRKY31 participates in regulating plant cold sensitivity. Collectively, our findings provide a comprehensive transcriptional overview of PBS occurrence and elucidate the molecular mechanism by which ethylene reduces the cold sensitivity of 'Huangguan' fruit as well as the potential role of PbWRKY31 in this process.

The Importance of Fatty Acid Precision Nutrition: Effects of Dietary Fatty Acid Composition on Growth, Hepatic Metabolite, and Intestinal Microbiota in Marine Teleost Trachinotus ovatus.

Our recent study demonstrated that diet with blend oil (named BO1) as lipid, which is designed on the base of essential fatty acid requirement of Trachinotus ovatus, achieved good performance. Here, to confirm its effect and investigate the mechanism, three isonitrogenous (45%) and isolipidic (13%) diets (D1-D3) only differing in dietary lipids, which were, respectively, fish oil (FO), BO1, and blend oil 2 (BO2) consisting of FO and soybean oil at 2 : 3, were formulated and used to feed the T. ovatus juveniles (average initial weight: 7.65 g) for 9 weeks. The results showed that the weight gain rate of fish fed D2 was higher than that of fish fed D3 (P < 0.05) and had no significant difference from that of fish fed D1 (P > 0.05). Correspondingly, compared with the D3 group, fish of the D2 group exhibited better oxidative stress parameters such as lower serum malondialdehyde content and inflammatory indexes in the liver such as the lower expression level of genes encoding four interleukin proteins and tumor necrosis factor α, as well as higher hepatic immune-related metabolites such as valine, gamma-aminobutyric acid, pyrrole-2-carboxylic acid, tyramine, l-targinine, p-synephrine, and butyric acid (P < 0.05). Furthermore, the intestinal probiotic (Bacillus) proportion was significantly higher, while the pathogenic bacteria (Mycoplasma) proportion was significantly lower in the D2 group than that in the D3 group (P < 0.05). The main differential fatty acids of diet D2 were close to those of D1, while the levels of linoleic acid and n-6 PUFA, as well as the ratio of DHA/EPA of D3, were higher than those of D1 and D2. These results indicated that the better performance of D2 such as enhancing growth, reducing oxidative stress, and improving immune responses and intestinal microbial communities in T. ovatus may be mainly due to the good fatty acid composition of BO1, which indicated the importance of fatty acid precision nutrition.

Fruit bagging reduces the postharvest decay and alters the diversity of fruit surface fungal community in 'Yali' pear.

BACKGROUND: Fruit bagging is an effective technique for fruit protection in the orchard management. Bagging can create a micro-environment for fruit growth and affect fruit quality during storage, in which the diversity of microorganisms may play an important role. Therefore, various methods including biochemistry, analytical chemistry, and bioinformatics methods were used to reveal the influences of fruit bagging on postharvest fruit quality, physiological characters, decay and surface fungal community of 'Yali' pear fruit were investigated in this study. RESULTS: Fruit bagging significantly decreased the postharvest decay after 15 days of ambient storage. There were no significant differences in fruit firmness, titratable acid and ethylene production rate between the fruit-bagging and non-bagging group after 15 days of storage, while the soluble solids contents (SSC) and respiration rate in non-bagging fruit was significantly higher than that in fruit-bagging after 15 days of storage. Furthermore, the surface microbes of pear were collected and determined by the new generation sequencing technology. The alpha diversity of fungi in non-bagging fruit decreased significantly after 15 days of storage, while there were no significant changes in bagging fruit. Ascomycota and Basidiomycota were the two major phyla detected in the bagging fruit, and the dominant fungal genera were Alternaria (23.7%), Mycosphaerella (17.25%), Vishniacozyma (16.14%), and Aureobasidium (10.51%) after 15 days of storage. For the non-bagging pear, Ascomycota was the only phylum detected, and the dominant genera was Pichia (83.32%) after 15 days of storage. The abundance of Pichia may be regarded as the biomarker to indicate the degree of fruit decay. CONCLUSIONS: This study showed that fruit bagging could significantly reduce postharvest fruit decay and respiration rate of 'Yali' pear. Significant differences were found in fungal composition between bagging and non-bagging pear after storage for 0 or 15 days. Fruit bagging maintained the diversity of fungi on the fruit surface, increased the abundance of non-pathogenic fungi, and even antagonistic fungi such as Aureobasidium, Vishniacozyma, and Mycosphaerella. A reduction in the abundance of pathogenic fungi and incidence of postharvest decay during the storage of 'Yali' pear were also recorded. In conclusion, fruit-bagging changed the fungal diversity on fruit surface of 'Yali' pear, which had significant effect on reducing postharvest fruit decay, and thus prolong the storage period of 'Yali' pears. The future thrust of this study will focus on the isolation of fungi or bacteria from pear fruit surface and identify their roles in causing fruit decay and changing fruit quality during storage.

Beneficial effects of re-feeding high α-linolenic acid diets on the muscle quality, cold temperature and disease resistance of tilapia.

To investigate the effects of re-feeding high α-linolenic acid (ALA) diets on the muscle quality, cold temperature and disease resistance of the tilapia with nutritional history of soybean oil diets, three experimental diets with linoleic aicd (LA)/ALA ratios at 9 (D1, taking soybean oil as lipid sources), 3 and 1 (D2 and D3, taking soybean and linseed oils as lipid sources) were prepared to re-feed juveniles for 10 weeks, and the growth performance, muscle quality were analyzed. After the re-feeding trial, the fish were fasted for 8 weeks at cold temperature (15°C-20 °C) and then subjected to the Aeromonas hydrophila challenge, and the cold temperature and disease resistance of the fish were evaluated. It was shown that a comparable growth performance was detected among the three dietary groups, while, the high feed efficiency and low viscerosomatic and hepatosomatic index were detected in the D2 and D3 groups compared with the D1 group. In addition, the docosahexaenoic acid (DHA) and n-3 polyunsaturated fatty acid (PUFA) levels of the muscle increased in a parallel pattern with the dietary ALA levels, and the muscular tenderness, adhesiveness, and chewiness were modified substantially in fish fed the diets D2 and D3. After 8-week fasting at cold temperature, the low serum total antioxidant capacity (T-AOC) and malondialdehyde (MDA) levels, and high serum lysozyme (LZM) and C3 levels were observed in the D2 and D3 groups compared with the D1 group. It was also shown that high eicosapentaenoic acid (EPA), DHA, and n-3 PUFA levels were observed in the intestine, liver, and spleen of fish from D2 and D3 groups. Correspondingly, in the fish of the D2 and D3 groups, the mRNA levels of lzm in the liver, intestine, and spleen, and c3 in the intestine and spleen were increased, while the mRNA levels of il-1ß, ifn-γ, and tnf-α in the intestine, and ifn-γ, tnf-α in the liver, as well as spleen il-1ß, were decreased. Furthermore, the survival at day 15 post-challenge of A. hydrophila in the D2 and D3 groups were higher than those of the D1 group. The results demonstrated that re-feeding high ALA diets were beneficial to the muscle quality, cold temperature and disease resistance in the tilapia, and provide a basis for selecting the dietary lipid sources of tilapia pre-winter feed.

Effects of dietary leucine and valine levels on growth performance, glycolipid metabolism and immune response in Tilapia GIFT Oreochromis niloticus.

An 8-week feeding trial was performed to evaluate the effects of dietary leucine (Leu) and valine (Val) levels on growth performance, glycolipid metabolism and immune response in Oreochromis niloticus. Fish (15.23 ± 0.05 g) were randomly fed four diets containing two Leu levels (1.2% and 2.3%) and two Val levels (0.7% and 1.4%) as a 2 × 2 experimental design (LL-LV, LL-HV, HL-LV and HL-HV). Compared with LL-LV group, the growth parameters (final weight, daily growth coefficient (DGC) and growth rate per metabolic body weight (GRMBW)), feed conversion rate (FCR), the activities of intestinal amylase, lipase, creatine kinase (CK) and Na+, K+-ATPase, liver NAD+/NADH ratio, as well as the expression of SIRT1, GK, PK, FBPase, PPARα, CPT IA, ACO and IL10 all increased significantly in the HL-LV group; however, in the high Val group, final weight, DGC, GRMBW, intestinal enzyme activities, as well as the expression of PEPCK, SREBP1, FAS, IL8 and IL10 of the HL-HV group were significantly lower than those of the LL-HV group, while the opposite was true for the remaining indicators. Significant interactions between dietary Leu and Val were observed in final weight, DGC, GRMBW, plasma IL1ß and IL6 levels, intestinal amylase and CK activities, liver NAD+/NADH ratio, as well as the expression of SIRT1, PK, PEPCK, FBPase, SREBP1, FAS, PPARα, CPT IA, ACO, NF-κB1, IL1ß, IL6 and IL10. The highest values of growth parameters, intestinal enzyme activities and expression of SIRT1, FBPase, PPARα, CPT IA and ACO were observed in the HL-LV group, while the opposite was true for the expression of SREBP1, FAS, PPARα, NF-κB1, IL1ß and IL6. Overall, our findings indicated that dietary Leu and Val can effect interactively, and fish fed with diets containing 2.3% Leu with 0.7% Val had the best growth performance and hepatic health status of O. niloticus.

Comparative transcriptome analysis reveals the mechanism involving ethylene and cell wall modification related genes in Diospyros kaki fruit firmness during ripening.

Rapid loss of firmness is a major handicap for persimmon (Diospyros kaki Thunb.) transportation and retail. The present study employed a comparative transcriptomic approach to elucidate the mechanism involving ethylene and cell wall modification related genes in fruit firmness control of two cultivars during post harvest ripening. In contrast to the short shelf life cultivar (Mopan), the long shelf life cultivar (Yoho) kept high firmness during ripening. Extensive loss of firmness in Mopan drove an intense transcriptional activity. Globally, Mopan and Yoho shared very few common differentially expressed structural genes and regulators. Yoho strongly repressed the expression of ACC synthase and several classes of cell wall degradation genes at the onset of ripening and only induced them during late ripening period. Various ERF, WRKY, MYB, bHLH transcription factors were found highly active during fruit ripening. Overall, this study generates novel gene resources as important tools for extending persimmon shelf life.

RNA-Seq Analysis Identifies Transcription Factors Involved in Anthocyanin Biosynthesis of 'Red Zaosu' Pear Peel and Functional Study of PpPIF8.

Red-skinned pears are favored by people for their attractive appearance and abundance of anthocyanins. However, the molecular basis of anthocyanin biosynthesis in red pears remains elusive. Here, a comprehensive transcriptome analysis was conducted to explore the potential regulatory mechanism of anthocyanin biosynthesis in 'Red Zaosu' pear (Pyrus pyrifolia × Pyrus communis). Gene co-expression analysis and transcription factor mining identified 263 transcription factors, which accounted for 6.59% of the total number of transcription factors in the pear genome in two gene modules that are highly correlated with anthocyanin biosynthesis. Clustering, gene network modeling with STRING-DB, and local motif enrichment analysis (CentriMo) analysis suggested that PpPIF8 may play a role in anthocyanin biosynthesis. Furthermore, eight PIFs were identified in the pear genome, of which only PpPIF8 was rapidly induced by light. Functional studies showed that PpPIF8 localizes in the nucleus and is preferentially expressed in the tissue of higher levels of anthocyanin. The overexpression of PpPIF8 in pear peel and pear calli promotes anthocyanin biosynthesis and upregulates the expression of anthocyanin biosynthesis genes. Yeast-one hybrid and transgenic analyses indicated that PpPIF8 binds to the PpCHS promoter to induce PpCHS expression. The positive effect of PpPIF8 on anthocyanin biosynthesis is different from previously identified negative regulators of PyPIF5 and MdPIF7 in pear and apple. Taken together, our data not only provide a comprehensive view of transcription events during the coloration of pear peel, but also resolved the regulatory role of PpPIF8 in the anthocyanin biosynthesis pathway.

Changes in α-Farnesene and Phenolic Metabolism and the Expression of Associated Genes during the Development of Superficial Scald in Two Distinct Pear Cultivars.

Superficial scald is a postharvest physiological disorder that occurs in pear during and after cold storage. In this study, the superficial scald index; α-farnesene and its oxidation products, conjugated trienols (CTols); phenolic content; and the expression of its related genes were investigated in two different pear cultivars, 'Wujiuxiang' (Pyrus communis L.) and 'Yali' (Pyrus bretschneideri R.), following 115 days of cold storage at 0 °C followed by 7 days of shelf life at 20 °C. The results indicated that the superficial scald occurred after 115 days of cold storage and became more severe during the shelf life of the 'Wujiuxiang' pear, whereas no scald was observed in 'Yali'. The α-farnesene levels increased rapidly at first and then decreased, while the CTols contents increased significantly in 'Wujiuxiang' as compared to 'Yali', and the expression levels of the genes involved in α-farnesene and CTols metabolism (HMGR1, HMGR2, GSTU7, GPX5, and GPX6), as well as the phenolic synthesis (PAL1, PAL2, C4H1, 4CL2, C3H, and ANR) of the peel, were significantly up-regulated at the onset of the superficial scald. In addition, the relative conductivity and contents of catechin and epicatechin were higher, and the expression level of the laccase gene (LAC7) significantly increased with the development of superficial scald, while lower contents of chlorogenic acid, arbutin, and isorhamnetin-3-3-glucoside, as well as the lower expression levels of a phenolic-synthesis-related gene (C4H3) and polyphenol oxidase genes (PPO1 and PPO5), were noticed in 'Wujiuxiang' as compared to 'Yali'. The results indicated that the onset and progression of superficial scald were associated with the accumulation of CTols, cell membrane breakdown, and higher catechin, epicatechin, and rutin contents, as well as the expression of associated genes of the peels of pear fruit.

Weighted gene coexpression correlation network analysis reveals a potential molecular regulatory mechanism of anthocyanin accumulation under different storage temperatures in 'Friar' plum.

BACKGROUND: Flesh is prone to accumulate more anthocyanin in postharvest 'Friar' plum (Prunus salicina Lindl.) fruit stored at an intermediate temperature. However, little is known about the molecular mechanism of anthocyanin accumulation regulated by storage temperature in postharvest plum fruit. RESULTS: To reveal the potential molecular regulation mechanism of anthocyanin accumulation in postharvest 'Friar' plum fruit stored at different temperatures (0 °C, 10 °C and 25 °C), the fruit quality, metabolite profile and transcriptome of its flesh were investigated. Compared to the plum fruit stored at 0 °C and 25 °C, the fruit stored at 10 °C showed lower fruit firmness after 14 days and reduced the soluble solids content after 21 days of storage. The metabolite analysis indicated that the fruit stored at 10 °C had higher contents of anthocyanins (pelargonidin-3-O-glucoside, cyanidin-3-O-glucoside, cyanidin-3-O-rutinoside and quercetin-3-O-rutinose), quercetin and sucrose in the flesh. According to the results of weighted gene coexpression correlation network analysis (WGCNA), the turquoise module was positively correlated with the content of anthocyanin components, and flavanone 3-hydroxylase (F3H) and chalcone synthase (CHS) were considered hub genes. Moreover, MYB family transcription factor APL (APL), MYB10 transcription factor (MYB10), ethylene-responsive transcription factor WIN1 (WIN1), basic leucine zipper 43-like (bZIP43) and transcription factor bHLH111-like isoform X2 (bHLH111) were closely related to these hub genes. Further qRT-PCR analysis verified that these transcription factors were specifically more highly expressed in plum flesh stored at 10 °C, and their expression profiles were significantly positively correlated with the structural genes of anthocyanin synthesis as well as the content of anthocyanin components. In addition, the sucrose biosynthesis-associated gene sucrose synthase (SS) was upregulated at 10 °C, which was also closely related to the anthocyanin content of plum fruit stored at 10 °C. CONCLUSIONS: The present results suggest that the transcription factors APL, MYB10, WIN1, bZIP43 and bHLH111 may participate in the accumulation of anthocyanin in 'Friar' plum flesh during intermediate storage temperatures by regulating the expression of anthocyanin biosynthetic structural genes. In addition, the SS gene may play a role in anthocyanin accumulation in plum flesh by regulating sucrose biosynthesis.

Effects of 1-methylcyclopropene on surface wax and related gene expression in cold-stored 'Hongxiangsu' pears.

BACKGROUND: Surface wax protects fruit from dehydration and pathogen erosion during storage. The surface wax of pears changes greatly during storage. In this work, the effect of ethylene action inhibitor 1-methylcyclopropene on wax accumulation and related gene expression in 'Hongxiangsu' pears during cold storage was investigated. RESULTS: The alkanes, alkenes, fatty acids, esters, aldehydes and triterpenoids on the fruit surface accumulated and peaked at day 180, but fatty alcohols decreased before day 90 and then increased in the control. Treatment with 1-MCP (1.0 µL L-1 ) reduced surface wax at day 180 of storage. Compared with the control, the wax crystals became smaller in 1-MCP-treated fruit on days 90 and 270. The 1-MCP decreased the expression levels of ethylene synthesis, perception and signal genes ACS1, ACO1, ERS1, ETR2, ERF1 and wax-related genes (LACS1, LACS2, KCS2, KCS9, KCS20, FDH, CER6, CER10, LTPG1, LTP3, LTP4, ABCG11 and ABCG12). CONCLUSION: These results suggested that 1-MCP suppressed ethylene synthesis and signal-pathway and wax-related gene expression; it also reduced the wax and the size of crystals on the fruit surface in cold-stored 'Hongxiangsu' pears. © 2018 Society of Chemical Industry.

Modified atmosphere packaging (MAP) and coating for improving preservation of whole and sliced Agaricus bisporus.

Freshness of mushrooms (Agaricus bisporus) was related to the internal atmosphere composition during modified atmosphere packaging (MAP) experiments using polyvinyl chloride (PVC) wrap, polyethylene-1 (PE-1) and PE-2 films. The packaged mushrooms were stored at 12 °C for 7 days and lightness value, browning index, weight loss and maturity index were also measured. The results obtained showed that the whiteness of whole mushrooms varied significantly with the type of coating (chitosan and CaCl2), but not with the type of packaging films. It was evident that the extent of darkening in whole mushroom was greater than in sliced ones after coated. In addition, mushroom in PE-2 package exhibited the lowest weight loss due to the lower permeability of film. And the type of packaging films significantly affected the maturity index of mushroom, where PE-2 packaging most effectively lowered maturity index for both whole and sliced mushrooms. By considering the overall quality, it was obvious that PE-2 packaging combined with coating treatment was the most effective to improve the preservation of mushrooms stored at 12 °C up to 7 days and satisfy consumer acceptance.

Potential of hyperspectral imaging for nondestructive determination of α-farnesene and conjugated trienol content in 'Yali' pear.

The sesquiterpene α-farnesene and its corresponding oxidation products, namely conjugated trienols (CTols) is well known to be correlated with the development of superficial scald, a typical physiological disorder after a long term of cold storage in pear fruit. In this work, hyperspectral imaging (HSI) technology was used for nondestructive predicting of α-farnesene and CTols [CT258, CT281 and CT(281-290)] content in 'Yali' pear. In order to obtain the best performance of calibration model and simplify the calibration model further, various preprocessing methods together with their combinations and different wavelength selection algorithms, including successive projections algorithm (SPA), competitive adaptive reweighted sampling (CARS) and uninformative variable elimination (UVE), were investigated and compared based on linear partial least square regression (PLSR) and nonlinear least square support vector machine (LS-SVM) models, respectively. In conclusion, compared to the PLSR models, the results of LS-SVM models based on original and preprocessing methods performed better for the prediction of α-farnesene and CTols, while the performance of LS-SVM models based on the selected characteristic wavelengths were worse. For α-farnesene, the best result was obtained by LS-SVM model based on MSC-FD pretreatment with the RPD value of 2.6, Rp = 0.925 and RMSEP = 4.387 nmol cm-2. And for CTols, CT281 performed better compared with CT258 and CT(281-290), achieving the result with RPD = 2.4, Rp = 0.913 and RMSEP = 2.734 nmol cm-2 based on LS-SVM model combined with SD pretreatment. The overall results illustrated HSI technology could be used for rapid and nondestructive prediction of α-farnesene and CTols in 'Yali' pear, which would be helpful for supporting postharvest decision systems.

Development of automatic arc sag measurement equipment for tensioned line tightening construction on overhead transmission lines.

Due to the low degree of automation of the existing arc droop measurement device, the tension line digital twin system is not yet able to simulate the change of arc droop in the actual engineering situation in a high degree of real time. To this end, a kind of arc droop automatic measuring equipment applicable to the working condition of tension frame line tightening construction is developed. In terms of hardware, firstly, the STC microcontroller is used to control the motor to achieve free movement of the equipment on the wire. Secondly, the Beidou positioning module is used to collect the spatial coordinates of each point on the wire, thereby obtaining the spatial attitude of the wire and calculating the final sag. Finally, LoRa technology with long transmission distance and low power consumption is selected for wireless transmission of controlled data and collected data. The software system of the device is equipped with the motor's action logic, which cooperates with the hardware to respond to the control commands issued by the terminal. The developed arc droop measurement equipment has been successfully applied in the project, compared with the traditional arc droop observation construction method construction efficiency increased by 28%, the difference between the observation file arc droop and the design arc droop after erection of the line is 1.96%. Digital simulation and remote guidance of arc sag variations by the digital twin system for tension racking lines was realized while ensuring the engineering requirements.

Influence of Bagging on Fruit Quality, Incidence of Peel Browning Spots, and Lignin Content of 'Huangguan' Pears.

The 'Huangguan' pear is one of the high-quality pear cultivars produced in China. However, the bagged fruit of the 'Huangguan' pear often suffers from peel browning spots after rain during their mature period. In this study, in an effort to discover the impact of bagging treatments on the occurrence of peel browning spots and fruit quality, fruits were covered by single-layer, two-layer, or triple-layer paper bags six weeks after reaching full bloom. The results showed that the bagged fruits were characterized by smooth surfaces and reduced lenticels compared with the unbagged ones. The unbagged and the two-layer bagged fruits had yellow/green peels, while the single- and triple-layer bagged ones had yellow/white peels. Compared with the unbagged fruits, the bagged fruits had higher vitamin C (Vc) contents and values of peel color indexes L and a and lower soluble solid contents (SSCs), titratable acid (TA) contents, absorbance index differences (IAD), and b values. Additionally, the triple-layer bagged group was superior to other groups in terms of fruit quality, but it also had the maximum incidence of peel browning spots. Before and after the appearance of peel browning spots, the bagged fruits had smoother and thinner cuticles compared with the unbagged ones. Furthermore, the triple-layer bagged fruits had minimum lignin contents and maximum phenolic contents in their peels, with minimum activity of lignin synthesis-related enzymes such as phenylalanine ammonia lyase (PAL), peroxidase (POD), and polyphenol oxidase (PPO), as well as minimum expressions of relevant genes such as cinnamyl alcohol dehydrogenase (CAD), cinnamoyl CoA reductase (CCR), 4-coumarate: coenzyme A ligase (4CL6), and cinnamate 4-hydroxylase (C4H1). It was deduced that POD activity and the relative expressions of CAD9, CCR3, CCR4, and CCR5 may play key roles in the occurrence of peel browning spots. In summary, lignin synthesis affected the incidence of peel browning spots in bagged 'Huangguan' pears. This study provides a theoretical basis for understanding the incidence of peel browning spots in 'Huangguan' pears.

Efficiently Substituting Dietary Fish Meal with Terrestrial Compound Protein Enhances Growth, Health, and Protein Synthesis in Largemouth Bass.

Inappropriate substitution of dietary fishmeal (FM) can adversely affect the growth, health, and metabolism of carnivorous fish species. To effectively reduce the amount of dietary FM in carnivorous largemouth bass (Micropterus salmoides), a terrestrial compound protein (Cpro) with chicken meal, bone meal, and black soldier fly protein was used to formulate four isoproteic (52%) and isolipidic (12%) diets, namely T1 (36% FM), T2 (30% FM), T3 (24% FM), and T4 (18% FM), for feeding juveniles (initial weight: ~12 g) for 81 days. Results indicated that the growth performance, feed efficiency, and morphological indicators, as well as muscle texture and edible quality of fish, did not differ significantly among the four groups. However, the muscle protein contents and ATP/AMP ratio of fish in the T4 group were significantly increased in comparison with those of fish in the T1 group, while the opposite was true for muscle glycogen. Compared with the T1 group, high serum total amino acid and MDA contents, as well as low AST activities, were observed in the T3 and T4 groups, and relatively high intestinal trypsin and lipase activities were found in the T2-T4 groups. The transcripts of intestinal proinflammatory cytokines (il-1ß, il-6, and tnf-α) were downregulated in the T2-T4 groups compared with T1 group, while the expression of anti-inflammatory cytokines (il-10) and tight junction (zo-1 and occludin) showed the reverse trend. The mRNA expression of positive regulators related to protein synthesis (sirt1, pgc1-α, pi3k, and akt) were significantly upregulated in the muscle of fish fed diets T3 and T4, while their negative regulators (4e-bp1) mRNA levels were downregulated. The results indicate that the dietary FM of largemouth bass could be effectively reduced to at least 18% by the Cpro, which is beneficial to health, digestion, and protein synthesis for maintaining accelerated growth.

Molecular characterization of vascular endothelial growth factor b from spotted sea bass (Lateolabrax maculatus) and its potential roles in decreasing lipid deposition.

Vascular endothelial growth factor B (VEGFB), a member of the VEGF family, exhibits limited angiogenic activity in mammals but plays an unexpected role in targeting lipids to peripheral tissues. However, its role in lipid metabolism in fish is unknown. In this study, the vegfb gene was cloned and characterized from spotted sea bass (Lateolabrax maculatus). It encodes 254 amino acids and possesses the typical characteristics of the Vegfb family, demonstrating high homology with those from other vertebrate species. The vegfb gene exhibits the highest expression levels in the liver, followed by the gills, intestine, and adipose tissues in spotted sea bass. In vivo, high-lipid diets decreased vegfb expression and increased lipid deposition in liver of fish. In vitro, palmitic acid + oleic acid treatment or vegfb knockdown significantly increased TG and TC contents, promoting lipid droplet deposition in hepatocytes. Vegfb overexpression has the opposite effects, inhibiting lipid deposition and downregulating fatty acid transport and adipogenesis genes. In contrast, the vegfb knockdown significantly upregulated the expression levels of c/ebpα, plin2, and dgat1 (P < 0.05). These results demonstrate that Vegfb may play an important role in reducing lipid deposition by regulating fatty acid transport and adipogenesis in the hepatocytes of spotted sea bass.

Geological challenges and stabilization strategies for phyllite rock slopes: a case study of Guang-Gansu expressway in Western China.

The increased occurrence and severity of natural disasters, such as landslides, have impacted the stability of phyllite rock slopes in the complex geological regions of Western China. This situation presents significant challenges for infrastructure development in the area. This study investigates the upper span bridgehead slope of Guang-Gansu expressway K550 + 031 as a case study to analyze the sliding failure mechanism of thousand rock slopes in the seismic fault zone and the supporting structure failure through field investigation and exploration. The analysis shows that the slope's rock mass is extensively fractured, primarily influenced by the Qingchuan fault zone. This geological activity leads to slope instability, worsened by seasonal rainfall. The phyllite undergoes alternating dry and wet cycles, weakening its mechanical strength, forming cracks, and accelerating slope displacement, subsidence, and cracking. This results in front slope instability, followed by gradual backward and step-by-step traction sliding deformation on both sides. The geological structure and seasonal rainfall damage the original bolt-grid beam-supporting structure. To address this issue, an anti-slide pile combined with a grid beam treatment method is proposed, and its effectiveness is verified through deep displacement monitoring. This study emphasizes the significance of integrating geological structure and seasonal rainfall impacts into infrastructure design within complex geological areas, ensuring slope and supporting structure stability.