Obesity has become a global threat to health;however,the available drugs for treating obesity are limited.We investigated the anti-obesity effect of hydroxy-α-sanshool(HAS),an amide derived from the fruit of Zanthoxy...Obesity has become a global threat to health;however,the available drugs for treating obesity are limited.We investigated the anti-obesity effect of hydroxy-α-sanshool(HAS),an amide derived from the fruit of Zanthoxylum bungeanum,which promotes the management of obesity by triggering the browning of white adipose tissue(WAT)targeting the membrane receptor of transient receptor potential vanilloid 1(TRPV1).However,HAS easily undergoes configuration transformation and oxidative degradation.The short peptide CKGGRAKDC or adipose-targeting sequence(ATS)binds specifically to prohibitin on the surface of WAT cells and can be used as recognition assembly to enhance adipocyte targetability.Furthermore,mesoporous silica nanoparticles(MSNs)are widely used in drug delivery systems because of their large specific surface area and pore volume.Therefore,HAS-loaded adipose-targeted MSNs(MSNs-ATS)were developed to enhance the adipocyte targetability,safety,and efficacy of HAS,and tested on mature 3T3-L1 cells and obese mouse models.MSNs-ATS showed higher specificity for adipocyte targetability without obvious toxicity.HAS-loaded MSNs-ATS showed anti-obesity effects superior to those of HAS alone.In conclusion,we successfully developed adipocyte-targeted,HAS-loaded MSNs with good safety and anti-obesity effects.展开更多
During the development of diet-induced obesity,the change of energy matebolism is closely related to the function of the circadian clock in mammals.Luteolin(LU),one of the most common natural flavonoids riched in many...During the development of diet-induced obesity,the change of energy matebolism is closely related to the function of the circadian clock in mammals.Luteolin(LU),one of the most common natural flavonoids riched in many edible plants,can ameliorate obesity by activating adipose tissue browning,but its effect on circadian clock in this process remains poorly understood.Here we found that dietary LU improved circadian misalignment of energy expenditure in high-fat diet(HFD)-fed wild-type(WT)mice.Moreover,dietary LU efficiently elevated uncoupling protein 1 levels in adipose tissue during the dark period,which was similar to the LU-increased hepatic PER2 expressions.Hepatic peroxisome proliferators-activated receptorsα(PPARα)/recombinant retinoid X receptorα(RXRα)/fibroblast growth factor 21(FGF21)pathway was rhythmically elevated by dietary LU in HFD-fed WT mice,whereas the promotion was inhibited in Per2^(-/-)mice.Meanwhile,Per2 deletion abolished the effects of dietary LU on adipose tissue browning in HFD-fed mice.Further,LU treatment directly activated PPARα/RXRα/FGF21 signaling in primary cultured hepatocytes from WT mice rather than Per2^(-/-)mice.Taken together,the deletion of the core clock component Per2 impedes LUinduced adipose tissue browning through weakening PPARα/RXRα/FGF21 pathway in mice,providing a new insight into the interplay of energy metabolism and circadian clock for the anti-obesity activity of LU.展开更多
Gut microbiota regulate the activation of adipose browning,which promote energy dissipation and combat diet-induced obesity.Pomegranate peel polyphenols(PPPs)have been shown to reduce obesity,regulate lipid metabolism...Gut microbiota regulate the activation of adipose browning,which promote energy dissipation and combat diet-induced obesity.Pomegranate peel polyphenols(PPPs)have been shown to reduce obesity,regulate lipid metabolism in adipose tissue,and modulate the composition of gut microbiota in animal fed high-fat diet(HFD).However,the role of gut microbiota in the improvement of obesity by PPPs has not been elucidated.In current study,we applied antibiotics to inhibit gut microbiota in mice fed HFD and treated with PPPs.The results showed that the inhibition of gut microbiota impair the effect of PPPs on reducing obesity and promoting adipose browning,and change the fecal metabolomic profiles in respond to PPPs.Moreover,the inhibition of gut microbiota supressed the promotive effects of PPPs on the levels of Akkermansia and microbiota-related metabolites,such as urolithin A,short-chain fatty acids(SCFAs),and bile acids(BAs),which were associated with activating adipose browning.Therefore,our results suggested that the presence of gut microbiota is essential for PPPs to ameliorate HFD-induced obesity.The related bacteria or metabolites generated by the interaction between PPPs and microbiota promote adipose browning and facilitate the beneficial effects of PPPs.展开更多
[Objective] Pericarp browning in the postharvest litchi significantly reduced its commercial value and limited the expanding of litchi markets. Physiological changes during the process of pericarp browning were determ...[Objective] Pericarp browning in the postharvest litchi significantly reduced its commercial value and limited the expanding of litchi markets. Physiological changes during the process of pericarp browning were determined in order to identify the underlying mechanisms. [Method] Matured Feizixiao fruits were stored at 25 ℃ and 70%±5% relative humidity. The physiological changes happened in pericarp during storage were tested at an 8-hour interval. [Result] The fruit of Feizixiao (Litchi chinensis Sonn. cv Feizixiao) turned completely brown within 72 h after being harvested under the experimental conditions. Sharp increase of the browning index occurred from 48 to 64 hours after harvest (HAH). With the browning of pericarp,water content of the whole fruit and pericarp decreased continuingly. In contrast,there were no significant changes in the water content of pulp during the same period. MDA content,pH value and relative leakage rate of pericarp were increased during storage. Most of pigment contents including anthocyanin,flavonoid,phenols,chlorophyll a and total chlorophyll decreased. POD activity was initially increased in 32 HAH and then decreased afterwards. PPO activity was decreased continuously,while the activities of catalase and superoxide dismutase exhibited the pattern of 'increasing-decreasing-increasing' as the storage time progressed. Correlation,stepwise regression and path analyses showed that water loss of pericarp was the major factor of pericarp browning. Principal and cluster analyses showed that there were two stages of pericarp browning during the course of litchi storage. [Conclusion] Water status of pericarp was the most important factor affecting pericarp browning. The pericarp browning happened by stages,which was mainly determined by the water loss of pericarp.展开更多
[Objective] This study aimed to investigate the browning of T. cuspidata cells in suspension culture and provide the guidance for the cell suspension culture of T. cuspidata. [Method] T. cuspidata callus was used as e...[Objective] This study aimed to investigate the browning of T. cuspidata cells in suspension culture and provide the guidance for the cell suspension culture of T. cuspidata. [Method] T. cuspidata callus was used as experimental materials, to explore the effect of different medium, N/P ratio, pH, shaking speed, illumination time and light intensity and other factors on browning of T. cuspidata cells in suspension culture. [Result] Non-browning callus was transferred to 2MB5 medium （pH 7.0） for illumination culture at 22℃ under light intensity of 1 500 lx with shaking speed of 90 r/min for 24 h. Results showed that the cell browning was significantly inhibited. [Conclusion] This study laid the foundation for cell suspension culture of T. cuspidata and had important significance to the large-scale industrial production of paclitaxel.展开更多
Brown callus derived from anther limited the application of anther culture in balsam pear. In order to establish a more perfect regeneration system from anther cultuer, the effects of low temperature pretreatment, 2,4...Brown callus derived from anther limited the application of anther culture in balsam pear. In order to establish a more perfect regeneration system from anther cultuer, the effects of low temperature pretreatment, 2,4-dichlorophenoxyacetic acid （2,4-D）, vitamin C （Vc） and silver nitrate （AgNO3） on callus induction and browning in anther culture of balsam pear （Momordiea charantia L.） were investigated. The results showed that after pretreatment at 4 ℃ for 1 day, callus induction rate was the highest and browning rate was the lowest. Anthers on MS medium supplemented with 2,4-D 0.5 mg/L formed more and better callus. The medium supplemented with Vc or AgNO3 was advantageous to the induction of callus and reduction of browning. When cultured on medium supplemented with 50 mg/L Vc or 5 mg/L AgNO3, callus induction rate was the highest and browning rate was rather low.展开更多
We conducted a field campaign to investigate the chemical composition,sources,and light absorption of submicron aerosols(PM_(1))from early 2022 in Nanjing,China.The average concentration of PM_(1) was 31μg m^(−3),org...We conducted a field campaign to investigate the chemical composition,sources,and light absorption of submicron aerosols(PM_(1))from early 2022 in Nanjing,China.The average concentration of PM_(1) was 31μg m^(−3),organics(33%)constituted the largest fraction,followed by nitrate(30%),sulfate(18%),ammonium(15%),chloride(3%),and rBC(2%).Four organic aerosol(OA)subcomponents were identified,including two primary OA(POA)and two secondary OA(SOA).The less-oxidized SOA(LO-OOA)contributes the most to the total OA mass(59%).LO-OOA is tightly correlated with the tracer ion C_(2)H_(4)O_(2)^(+)from levoglucosan,and another aged biomass-burning derived species,K_(3)SO_(4)^(+),suggesting it was likely influenced by aged biomass-burning OA.Our study also revealed that fireworks during the Spring Festival have a detrimental impact on air quality,contributing to secondary formation and accumulation under static winter meteorological conditions,prolonging the pollution duration.Also,LO-OOA was found to have the strongest light-absorbing ability.Our results highlight that the light absorption of LO-OOA can mainly be attributed to the C_(x)H_(y)N^(+) family,increased with the double-bond equivalent value.The more-oxidized SOA(MO-OOA)exhibited a negligible light absorption and was strongly correlated with daytime photochemical processes,implying a light-bleaching effect.This study enhances our understanding of the regional contribution of biomass combustion and fireworks to PM_(1) pollution in Nanjing,a typical megacity in the Yangtze River Delta region,during winter,aiding in the development of strategies for long-term air quality improvement in the region.展开更多
Maintaining a stable body temperature is essential for survival.Multiple brain regions contribute to thermoregulation,but their specific characteristics and underlying neural mechanisms in the coordination of thermore...Maintaining a stable body temperature is essential for survival.Multiple brain regions contribute to thermoregulation,but their specific characteristics and underlying neural mechanisms in the coordination of thermoregulation are not fully clarified.Here,we reveal the distinct roles of two preoptic subregions in warm defense in mice:the anterior ventromedial preoptic area(VMPO)and the ventral part of the lateral preoptic nucleus(vLPO).VMPO vesicular glutamate transporter 2(Vglut2)neurons exhibited dramatic responses to rising temperatures,producing a marked decrease in core temperature by warm defense responses.In contrast,excitatory and inhibitory vLPO neurons responded gently to warm stimuli,exerting moderate effects on warm defense.Further postsynaptic tracing and caspase ablation identified distinct cell type-specific downstream targets in the dorsomedial hypothalamus(DMH)mediating these different warm defense responses.Taken together,our findings reveal distinct yet complementary pathways in the preoptic DMH network that enable both rapid and fine-tuned regulation of body temperature under elevated thermal conditions.展开更多
This paper explored the three dramatic features intrinsic in Robert Browning's poems of dramatic monologue, namely, the employment of first-person point of view, the use of irony, and the intricate psychological e...This paper explored the three dramatic features intrinsic in Robert Browning's poems of dramatic monologue, namely, the employment of first-person point of view, the use of irony, and the intricate psychological exploration and vivid characterization. Such features are crucial in the successful presentation of various human nature and experience with profundity, making his poems an enduring classic in the English literature.展开更多
Polyphenolic compound in processing apple （Malus domestica Borkh.） varieties and the relationship between polyphenol content and enzymatic browning were studied to provide reference for raw material selection and pr...Polyphenolic compound in processing apple （Malus domestica Borkh.） varieties and the relationship between polyphenol content and enzymatic browning were studied to provide reference for raw material selection and processing method optimization. The content of polyphenol compound in 10 processing apple varieties （4 cider and 6 juice varieties） were analyzed using the Folin-Ciocalteu method and HPLC. The degree of browning and the activities of polyphenol oxidase were also studied. The content and proportion of the polyphenol varied depending on the variety. Bitter varieties globally showed a higher polyphenol concentration than sweet or acid varieties. Proanthocyanidins, chlorogenic acid, （＋）-catechin, （-）-epicatechin were high-concentrated polyphenols in apple fruits. Phloridzin, the unique polyphenol of apple, was abundant in the bitter variety Frequin rouge fruit. Total polyphenols, proanthocyanidins, （＋）-catechin, and phloridzin had higher correlations with browning. The correlation was low between chlorogenic acid and browning. The polyphenolic profiles were correlated with the apple types. Cider apples contained more polyphenol than juice apple varieties. The content of flavan-3-ol has a close relationship with fruit browning.展开更多
Peel browning of pomegranate fruit is the key problem during storage. The mechanism of it during storage in relation to the technology of the browning control was studied in this paper. The effects of storage temperat...Peel browning of pomegranate fruit is the key problem during storage. The mechanism of it during storage in relation to the technology of the browning control was studied in this paper. The effects of storage temperature, gas component and pH value on peel browning of sweet pomegranate fruit in Lintong, Shaanxi Province, China, were investigated. Change in tannin content was measured and the relationship between the activities of ascorbic acid oxidase （AAO）, polypenoloxidase （PPO）, peroxidase （POD）, catalase （CAT） and peel browning was analysed. The results showed tannin was the basic substance of pomegranate peel browning. The activities of the browning index of peel were correlated positively with AAO, PPO and POD, correlated negatively with CAT activity. Application of intermittent warming for 24 h at （15 ± 0.5）℃ every 5 days for pomegranate fruit storage under the conditions of pH 4.0, （5.0± 0.5）℃ and 5.0% CO2 ＋ 8.0% O2 ＋ 87.0% N2 gas component could delay browning, with the browning index being 0.15 after 120 days of storage. Enzymatic tannin denaturation was the main cause that led to peel browning of pomegranate fruit during storage. The browning control of pomegranate fruit peel was effective using intermittent warming storage with suitable pH, temperature and gas component.展开更多
Excess accumulation of white adipose tissue(WAT) causes obesity which is an imbalance between energy intake and energy expenditure. Obesity is a serious concern because it has been the leading causes of death worldwid...Excess accumulation of white adipose tissue(WAT) causes obesity which is an imbalance between energy intake and energy expenditure. Obesity is a serious concern because it has been the leading causes of death worldwide, including diabetes, stroke,heart disease and cancer. Therefore, uncovering the mechanism of obesity and discovering anti-obesity drugs are crucial to prevent obesity and its complications. Browning, inducing white adipose tissue to brown or beige(brite) fat which is brown-like fat emerging in WAT, becomes an appealing therapeutic strategy for obesity and metabolic disorders. Due to lack of efficacy or intolerable side-effects, the clinical trials that promote brown adipose tissue(BAT) thermogenesis and browning of WAT have not been successful in humans. Obviously, more specific means still need to be developed to activate browning of white adipose tissue. In this review, we summarized seven kinds of natural products(alkaloids, flavonoids, terpenoids, long chain fatty acids, phenolic acids, else and extract) promoting white adipose tissue browning which can ameliorate the metabolic disorders, including obesity, dislipidemia, insulin resistance and diabetes. Since natural products are important drug sources and the browning property plays a significant role in not only obesity treatment but also in type 2 diabetes(T2 DM) improvement, natural products of inducing browning may be an irreplaceable drug discovery orientation for obesity, diabetes and even other metabolic disorders.展开更多
This study investigated the effects of grape seed extract(GSE)on fresh and cooked meat color and premature browning(PMB)in ground meat patties(85% beef and 15% pork back fat)packaged under high-oxygen modified atmosph...This study investigated the effects of grape seed extract(GSE)on fresh and cooked meat color and premature browning(PMB)in ground meat patties(85% beef and 15% pork back fat)packaged under high-oxygen modified atmospheres(HiOx-MAP).The GSE was added to patties at concentrations of 0,0.10,0.25,0.50 and 0.75 g kg^(-1).This study evaluated the surface color,pH,lipid oxidation,and total viable counts(TVC)of raw patties,and the internal color and pH of patties cooked to a temperature of 66 or 71℃ over 10-day storage at 4℃.Compared with the control(0 g kg^(-1) GSE),GSE improved the color stability(P<0.05)and significantly inhibited the lipid and myoglobin oxidation of raw patties from day 5 to 10,but GSE had no effect(P>0.05)on TVC.Patties containing 0.50 and 0.75 g kg^(-1) GSE cooked to 66℃ exhibited greater(P<0.05)interior redness than the control and reduced the PMB of cooked patties in the late storage stage.These results suggested that 0.50 and 0.75 g kg^(-1) GSE can improve fresh meat color and minimize PMB of HiOx-MAP patties.展开更多
Huangguan pear (Pyrus bretschneideri Rehd cv. Huangguan) is a pear cultivar that rapidly developed in China. However, rapid postharvest browning appearing in fruit peel and core during storage and shelf life pose a ch...Huangguan pear (Pyrus bretschneideri Rehd cv. Huangguan) is a pear cultivar that rapidly developed in China. However, rapid postharvest browning appearing in fruit peel and core during storage and shelf life pose a challenge for their marketing. The potential for low temperature conditioning (LTC) treatment to inhibit peel browning and improve quality of Huangguan pears in storage and shelf life was investigated. Pears were treated at 8℃ - 9℃ for 1, 3, 6 and 9 d, respectively, physiological indexes, including peel and core browning, core breakdown, malondialdehyde (MDA) content and ethanol content were determined and quality in storage period and shelf life was evaluated in this paper. LTC treatment alleviated peel browning and core browning either in storage or shelf life remarkably;it also delayed the decline of firmness, total soluble solids and titratable acidity in storage to some extent, inhibited ethanol and MDA content both in storage and shelf life effectively and maintained juiciness and crispness of pear fruit in shelf life. These results showed that LTC can serve as an important tool for the regulation of Huangguan pears external and internal quality in storage and shelf life with economic benefits and LTC treatment for 6 d was the optimum condition in the present study.展开更多
Mulberry (Morus alba L.) leaf is a well-established traditional Chinese botanical and culinary resource. It has found widespread application in the management of diabetes. The bioactive constituents of mulberry leaf, ...Mulberry (Morus alba L.) leaf is a well-established traditional Chinese botanical and culinary resource. It has found widespread application in the management of diabetes. The bioactive constituents of mulberry leaf, specifically mulberry leaf flavonoids (MLFs), exhibit pronounced potential in the amelioration of type 2 diabetes (T2D). This potential is attributed to their ability to safeguard pancreatic β cells, enhance insulin resistance, and inhibit α-glucosidase activity. Our antecedent research findings underscore the substantial therapeutic efficacy of MLFs in treating T2D. However, the precise mechanistic underpinnings of MLF’s anti-T2D effects remain the subject of inquiry. Activation of brown/beige adipocytes is a novel and promising strategy for T2D treatment. In the present study, our primary objective was to elucidate the impact of MLFs on adipose tissue browning in db/db mice and 3T3-L1 cells and elucidate its underlying mechanism. The results manifested that MLFs reduced body weight and food intake, alleviated hepatic steatosis, improved insulin sensitivity, and increased lipolysis and thermogenesis in db/db mice. Moreover, MLFs activated brown adipose tissue (BAT) and induced the browning of inguinal white adipose tissue (IWAT) and 3T3-L1 adipocytes by increasing the expressions of brown adipocyte marker genes and proteins such as uncoupling protein 1 (UCP1) and beige adipocyte marker genes such as transmembrane protein 26 (Tmem26), thereby promoting mitochondrial biogenesis. Mechanistically, MLFs facilitated the activation of BAT and the induction of WAT browning to ameliorate T2D primarily through the activation of AMP-activated protein kinase (AMPK)/sirtuin 1 (SIRT1)/peroxisome proliferator-activated receptor-gamma coactivator 1α (PGC-1α) signaling pathway. These findings highlight the unique capacity of MLF to counteract T2D by enhancing BAT activation and inducing browning of IWAT, thereby ameliorating glucose and lipid metabolism disorders. As such, MLFs emerge as a prospective and innovative browning agent for the treatment of T2D.展开更多
Twigs of 2-3-year-old Platanus occidentalis L. were used as experimental material to find the causes for the contamination and browning in the initial stages of tissue cultures. To compare the degree of browning of ex...Twigs of 2-3-year-old Platanus occidentalis L. were used as experimental material to find the causes for the contamination and browning in the initial stages of tissue cultures. To compare the degree of browning of explants picked off from different growing seasons, the experimental material was excised from trees on each of the first ten days in January, March, May and July, 2006. The results indicated that the contamination and browning rates of the material cut off in January （14.2% and 30.6%, respectively） and March were somewhat lower than those in July. The pretreatment of soaking the explants in different anti-oxidants and absorbents at the same time could diminish some side effects. The pretreatment of using 10 g·L^-1 vitamin C reduced the contamination and brown- ing rate effectively. An orthogonal experiment showed that the optimal factor and level arrangement is 0.5 mg·L^-1BA, 2.0 g·L^-1 active carbon and 1.5 g·L^-1 PVP which resulted in a browning rate of only 16.5%. In general, sampling period, physical properties and pretreatment of explants are the main factors responsible for the contamination and browning of material in the initial stages of P. occidentalis tissue cultures.展开更多
In the storage of Radix Ophiopogonis, browning often happens to cause potential risk with regard to safety. Previously few reports investigate the browning of Radix Ophiopogonis. In this research, the causes and mecha...In the storage of Radix Ophiopogonis, browning often happens to cause potential risk with regard to safety. Previously few reports investigate the browning of Radix Ophiopogonis. In this research, the causes and mechanisms of the browning of Radix Ophiopogonis were preliminarily elucidated. Content determination by high-performance liquid chromatogra- phy （HPLC） and spectrophotometry, enzyme activity determination by colorimetry, and morphological observation by electron mi- croscopy were performed in the present study. Uniform design and three-dimensional response surfaces were applied to investigate the relationship between browning and storage factors. The cortex cell wall of browned Radix Ophiopogonis was ruptured. Compared with the normal Radix Ophiopogonis, cellulase and polyphenol oxidase enzymes were activated, the levels of 5-hydroxymethylfurfural （5-HMF）, total sugars, and reducing sugars were increased, while the levels of polysaccharides and methylophiopogonanone A were de- creased in browned Radix Ophiopogonis. The relationship between the storage factors and degree of browning （Y） could be described by following correlation equation： Y= - 0.625 4 ＋ 0.020 84 × X3 ＋ 0.001 514×X1×x X2 - 0.000 964 4 × X2 × X3. Accompanied with browning under storage conditions, the chemical composition of Radix Ophiopogonis was altered. Following the activation of cellulase, the rupture of the cortex cell wall and the outflow of cell substances flowed out, which caused the Radix Ophiopogonis tissue to become soft and sticky. The main causes of the browning were the production of 5-HMF, the activation of polyphenol oxidase, Maillard reactions and enzymatic browning. Browning could be effectively prevented when the air relative humidity （HR）, temperature, and moisture content were under 25% RH, 12 ℃ and 18%, respectively.展开更多
Obesity-induced type 2 diabetes is mainly due to excessive free fatty acids leading to insulin resistance.Increasing thermogenesis is regarded as an effective strategy for hypolipidemia and hypoglycemia.Ginsenoside is...Obesity-induced type 2 diabetes is mainly due to excessive free fatty acids leading to insulin resistance.Increasing thermogenesis is regarded as an effective strategy for hypolipidemia and hypoglycemia.Ginsenoside is a natural active component in Panax ginseng C.A.Meyer,and some of them enhance thermogenesis.However,there are few studies on the mechanism and target of ginsenosides enhancing thermogenesis.Using thermogenic protein uncoupling protein 1(UCP1)-luciferase reporter assay,we identifi ed ginsenoside F1 as a novel UCP1 activator in the ginsenosides library.Using pull down assay and inhibitor interference,we found F1 binds toβ3-adrenergic receptors(β3-AR)to enhance UCP1 expression via cAMP/PKA/CREB pathway.We also investigated the ability of F1 on energy metabolism in obesity-induced diabetic mice,including body weight,body composition and energy expenditure.The results of proteomics showed that F1 signifi cantly up-regulated thermogenesis proteins and lipolytic proteins,but down-regulated fatty acid synthesis proteins.Ginsenoside F1 increased thermogenesis and ameliorated insulin resistance specifi cally by promoting the browning of white adipose tissue in obese mice.Additionally,ginsenoside F1 improves norepinephrine-induced insulin resistance in adipocytes and hepatocytes,and shows a stronger mitochondria respiration ability than norepinephrine.These fi ndings suggest that ginsenoside F1 is a promising lead compound in the improvement of insulin resistance.展开更多
The preharvest internal browning of Nane plum fruit,with no visible effects on the appearance of the fruit,has become a serious problem in recent years in its production area in Guangdong Province,China.This study inv...The preharvest internal browning of Nane plum fruit,with no visible effects on the appearance of the fruit,has become a serious problem in recent years in its production area in Guangdong Province,China.This study investigated the effects of environmental factors,including temperature,on Nane plum internal browning.Plum orchards at different elevations with different incidences of internal browning were selected.Using fruits with different internal browning incidence levels,the internal browning mechanism was analyzed with transcriptome and metabolome analyses.The results revealed decreased internal browning at high altitudes.Shading treatment significantly reduced internal browning,whereas bagging and insect-proof net-covering treatments significantly increased internal browning.Because bagging and net coverings increase the local ambient temperature,the findings suggest that high temperature is an important factor influencing the internal browning of Nane plum.The metabolome experiments showed that with increased internal browning,the levels of phenolic hydroxyls such as catechol increased,with simultaneous increases in hydrogen peroxide content and oxidase activity.It can be speculated that the oxidation of phenolic hydroxyl substances is the main cause of the preharvest browning of Nane plum.Transcriptome analysis revealed the increased expression of calcium signaling-related and downstream effector genes and indicated an important role of calcium in internal browning,possibly due to its increased content in the fruit.Further,with increasingly serious internal browning,genes related to photosynthesis were down-regulated,while genes related to senescence were up-regulated,thus suggesting the up-regulation of the process of cell senescence during internal browning.In conclusion,heat stress should be eliminated to reduce preharvest internal browning in Nane plum.展开更多
基金supported by the Natural Science Foundation of Sichuan Province(No.2022NSFSC0720)Research Center for the Development of the Comprehensive Health Industry and Rural Revitalization of Sichuan TCM(No.DJKYB202306)State Administration of Traditional Chinese Medicine of Sichuan Province of China(No.2020HJZX001).
文摘Obesity has become a global threat to health;however,the available drugs for treating obesity are limited.We investigated the anti-obesity effect of hydroxy-α-sanshool(HAS),an amide derived from the fruit of Zanthoxylum bungeanum,which promotes the management of obesity by triggering the browning of white adipose tissue(WAT)targeting the membrane receptor of transient receptor potential vanilloid 1(TRPV1).However,HAS easily undergoes configuration transformation and oxidative degradation.The short peptide CKGGRAKDC or adipose-targeting sequence(ATS)binds specifically to prohibitin on the surface of WAT cells and can be used as recognition assembly to enhance adipocyte targetability.Furthermore,mesoporous silica nanoparticles(MSNs)are widely used in drug delivery systems because of their large specific surface area and pore volume.Therefore,HAS-loaded adipose-targeted MSNs(MSNs-ATS)were developed to enhance the adipocyte targetability,safety,and efficacy of HAS,and tested on mature 3T3-L1 cells and obese mouse models.MSNs-ATS showed higher specificity for adipocyte targetability without obvious toxicity.HAS-loaded MSNs-ATS showed anti-obesity effects superior to those of HAS alone.In conclusion,we successfully developed adipocyte-targeted,HAS-loaded MSNs with good safety and anti-obesity effects.
文摘During the development of diet-induced obesity,the change of energy matebolism is closely related to the function of the circadian clock in mammals.Luteolin(LU),one of the most common natural flavonoids riched in many edible plants,can ameliorate obesity by activating adipose tissue browning,but its effect on circadian clock in this process remains poorly understood.Here we found that dietary LU improved circadian misalignment of energy expenditure in high-fat diet(HFD)-fed wild-type(WT)mice.Moreover,dietary LU efficiently elevated uncoupling protein 1 levels in adipose tissue during the dark period,which was similar to the LU-increased hepatic PER2 expressions.Hepatic peroxisome proliferators-activated receptorsα(PPARα)/recombinant retinoid X receptorα(RXRα)/fibroblast growth factor 21(FGF21)pathway was rhythmically elevated by dietary LU in HFD-fed WT mice,whereas the promotion was inhibited in Per2^(-/-)mice.Meanwhile,Per2 deletion abolished the effects of dietary LU on adipose tissue browning in HFD-fed mice.Further,LU treatment directly activated PPARα/RXRα/FGF21 signaling in primary cultured hepatocytes from WT mice rather than Per2^(-/-)mice.Taken together,the deletion of the core clock component Per2 impedes LUinduced adipose tissue browning through weakening PPARα/RXRα/FGF21 pathway in mice,providing a new insight into the interplay of energy metabolism and circadian clock for the anti-obesity activity of LU.
基金supported by the National Natural Science Foundation of China(32001679 and 31871801)the Science and Technology Research of Shaanxi Province(2021QFY07-03)+1 种基金supported by the Fundamental Research Funds for the Central Universities(GK202103098)the Scientific and Technological Achievements Commercialization Program of Shaanxi(2023-YDCGZH-13)。
文摘Gut microbiota regulate the activation of adipose browning,which promote energy dissipation and combat diet-induced obesity.Pomegranate peel polyphenols(PPPs)have been shown to reduce obesity,regulate lipid metabolism in adipose tissue,and modulate the composition of gut microbiota in animal fed high-fat diet(HFD).However,the role of gut microbiota in the improvement of obesity by PPPs has not been elucidated.In current study,we applied antibiotics to inhibit gut microbiota in mice fed HFD and treated with PPPs.The results showed that the inhibition of gut microbiota impair the effect of PPPs on reducing obesity and promoting adipose browning,and change the fecal metabolomic profiles in respond to PPPs.Moreover,the inhibition of gut microbiota supressed the promotive effects of PPPs on the levels of Akkermansia and microbiota-related metabolites,such as urolithin A,short-chain fatty acids(SCFAs),and bile acids(BAs),which were associated with activating adipose browning.Therefore,our results suggested that the presence of gut microbiota is essential for PPPs to ameliorate HFD-induced obesity.The related bacteria or metabolites generated by the interaction between PPPs and microbiota promote adipose browning and facilitate the beneficial effects of PPPs.
基金Supported by National Science Foundation of China ( GrantNo.30460085, 30960233)Open Foundation of Provincial Key Laboratory for Fruit and Vegetable Preservation of Hainan ( GrantNo. CH001)National Non-profit Institute Grant (ITBBZD2007-3-1)~~
文摘[Objective] Pericarp browning in the postharvest litchi significantly reduced its commercial value and limited the expanding of litchi markets. Physiological changes during the process of pericarp browning were determined in order to identify the underlying mechanisms. [Method] Matured Feizixiao fruits were stored at 25 ℃ and 70%±5% relative humidity. The physiological changes happened in pericarp during storage were tested at an 8-hour interval. [Result] The fruit of Feizixiao (Litchi chinensis Sonn. cv Feizixiao) turned completely brown within 72 h after being harvested under the experimental conditions. Sharp increase of the browning index occurred from 48 to 64 hours after harvest (HAH). With the browning of pericarp,water content of the whole fruit and pericarp decreased continuingly. In contrast,there were no significant changes in the water content of pulp during the same period. MDA content,pH value and relative leakage rate of pericarp were increased during storage. Most of pigment contents including anthocyanin,flavonoid,phenols,chlorophyll a and total chlorophyll decreased. POD activity was initially increased in 32 HAH and then decreased afterwards. PPO activity was decreased continuously,while the activities of catalase and superoxide dismutase exhibited the pattern of 'increasing-decreasing-increasing' as the storage time progressed. Correlation,stepwise regression and path analyses showed that water loss of pericarp was the major factor of pericarp browning. Principal and cluster analyses showed that there were two stages of pericarp browning during the course of litchi storage. [Conclusion] Water status of pericarp was the most important factor affecting pericarp browning. The pericarp browning happened by stages,which was mainly determined by the water loss of pericarp.
基金Supported by National Natural Science Foundation of China (31070164)Young Scientists Fund of Dalian (2006J23JH031)~~
文摘[Objective] This study aimed to investigate the browning of T. cuspidata cells in suspension culture and provide the guidance for the cell suspension culture of T. cuspidata. [Method] T. cuspidata callus was used as experimental materials, to explore the effect of different medium, N/P ratio, pH, shaking speed, illumination time and light intensity and other factors on browning of T. cuspidata cells in suspension culture. [Result] Non-browning callus was transferred to 2MB5 medium （pH 7.0） for illumination culture at 22℃ under light intensity of 1 500 lx with shaking speed of 90 r/min for 24 h. Results showed that the cell browning was significantly inhibited. [Conclusion] This study laid the foundation for cell suspension culture of T. cuspidata and had important significance to the large-scale industrial production of paclitaxel.
文摘Brown callus derived from anther limited the application of anther culture in balsam pear. In order to establish a more perfect regeneration system from anther cultuer, the effects of low temperature pretreatment, 2,4-dichlorophenoxyacetic acid （2,4-D）, vitamin C （Vc） and silver nitrate （AgNO3） on callus induction and browning in anther culture of balsam pear （Momordiea charantia L.） were investigated. The results showed that after pretreatment at 4 ℃ for 1 day, callus induction rate was the highest and browning rate was the lowest. Anthers on MS medium supplemented with 2,4-D 0.5 mg/L formed more and better callus. The medium supplemented with Vc or AgNO3 was advantageous to the induction of callus and reduction of browning. When cultured on medium supplemented with 50 mg/L Vc or 5 mg/L AgNO3, callus induction rate was the highest and browning rate was rather low.
基金support from the Natural Science Foundation of Jiangsu Province(Grant No.BK20240036)the National Natural Science Foundation of China(Grant Nos.U24A20515,22276099,and 22361162668)Guangxi Key Research and Development Program,China(Grant No.Guike AB24010074)。
文摘We conducted a field campaign to investigate the chemical composition,sources,and light absorption of submicron aerosols(PM_(1))from early 2022 in Nanjing,China.The average concentration of PM_(1) was 31μg m^(−3),organics(33%)constituted the largest fraction,followed by nitrate(30%),sulfate(18%),ammonium(15%),chloride(3%),and rBC(2%).Four organic aerosol(OA)subcomponents were identified,including two primary OA(POA)and two secondary OA(SOA).The less-oxidized SOA(LO-OOA)contributes the most to the total OA mass(59%).LO-OOA is tightly correlated with the tracer ion C_(2)H_(4)O_(2)^(+)from levoglucosan,and another aged biomass-burning derived species,K_(3)SO_(4)^(+),suggesting it was likely influenced by aged biomass-burning OA.Our study also revealed that fireworks during the Spring Festival have a detrimental impact on air quality,contributing to secondary formation and accumulation under static winter meteorological conditions,prolonging the pollution duration.Also,LO-OOA was found to have the strongest light-absorbing ability.Our results highlight that the light absorption of LO-OOA can mainly be attributed to the C_(x)H_(y)N^(+) family,increased with the double-bond equivalent value.The more-oxidized SOA(MO-OOA)exhibited a negligible light absorption and was strongly correlated with daytime photochemical processes,implying a light-bleaching effect.This study enhances our understanding of the regional contribution of biomass combustion and fireworks to PM_(1) pollution in Nanjing,a typical megacity in the Yangtze River Delta region,during winter,aiding in the development of strategies for long-term air quality improvement in the region.
基金supported by the National Natural Science Foundation of China(32171001,32371050,and 82371554).
文摘Maintaining a stable body temperature is essential for survival.Multiple brain regions contribute to thermoregulation,but their specific characteristics and underlying neural mechanisms in the coordination of thermoregulation are not fully clarified.Here,we reveal the distinct roles of two preoptic subregions in warm defense in mice:the anterior ventromedial preoptic area(VMPO)and the ventral part of the lateral preoptic nucleus(vLPO).VMPO vesicular glutamate transporter 2(Vglut2)neurons exhibited dramatic responses to rising temperatures,producing a marked decrease in core temperature by warm defense responses.In contrast,excitatory and inhibitory vLPO neurons responded gently to warm stimuli,exerting moderate effects on warm defense.Further postsynaptic tracing and caspase ablation identified distinct cell type-specific downstream targets in the dorsomedial hypothalamus(DMH)mediating these different warm defense responses.Taken together,our findings reveal distinct yet complementary pathways in the preoptic DMH network that enable both rapid and fine-tuned regulation of body temperature under elevated thermal conditions.
文摘This paper explored the three dramatic features intrinsic in Robert Browning's poems of dramatic monologue, namely, the employment of first-person point of view, the use of irony, and the intricate psychological exploration and vivid characterization. Such features are crucial in the successful presentation of various human nature and experience with profundity, making his poems an enduring classic in the English literature.
文摘Polyphenolic compound in processing apple （Malus domestica Borkh.） varieties and the relationship between polyphenol content and enzymatic browning were studied to provide reference for raw material selection and processing method optimization. The content of polyphenol compound in 10 processing apple varieties （4 cider and 6 juice varieties） were analyzed using the Folin-Ciocalteu method and HPLC. The degree of browning and the activities of polyphenol oxidase were also studied. The content and proportion of the polyphenol varied depending on the variety. Bitter varieties globally showed a higher polyphenol concentration than sweet or acid varieties. Proanthocyanidins, chlorogenic acid, （＋）-catechin, （-）-epicatechin were high-concentrated polyphenols in apple fruits. Phloridzin, the unique polyphenol of apple, was abundant in the bitter variety Frequin rouge fruit. Total polyphenols, proanthocyanidins, （＋）-catechin, and phloridzin had higher correlations with browning. The correlation was low between chlorogenic acid and browning. The polyphenolic profiles were correlated with the apple types. Cider apples contained more polyphenol than juice apple varieties. The content of flavan-3-ol has a close relationship with fruit browning.
基金the Natural Science Foundation of Shaanxi Province,China(2004C109)Key Technology R&D Program of Shaanxi Province,China(2003K02-G6)Agricultural Science and Technology Development of Xi'an City,China(NG200313).
文摘Peel browning of pomegranate fruit is the key problem during storage. The mechanism of it during storage in relation to the technology of the browning control was studied in this paper. The effects of storage temperature, gas component and pH value on peel browning of sweet pomegranate fruit in Lintong, Shaanxi Province, China, were investigated. Change in tannin content was measured and the relationship between the activities of ascorbic acid oxidase （AAO）, polypenoloxidase （PPO）, peroxidase （POD）, catalase （CAT） and peel browning was analysed. The results showed tannin was the basic substance of pomegranate peel browning. The activities of the browning index of peel were correlated positively with AAO, PPO and POD, correlated negatively with CAT activity. Application of intermittent warming for 24 h at （15 ± 0.5）℃ every 5 days for pomegranate fruit storage under the conditions of pH 4.0, （5.0± 0.5）℃ and 5.0% CO2 ＋ 8.0% O2 ＋ 87.0% N2 gas component could delay browning, with the browning index being 0.15 after 120 days of storage. Enzymatic tannin denaturation was the main cause that led to peel browning of pomegranate fruit during storage. The browning control of pomegranate fruit peel was effective using intermittent warming storage with suitable pH, temperature and gas component.
基金supported by the National Natural Science Foundation of China (No. 81770847)the Drug Innovation Major Project (No. 2018ZX09711001-003-005)CAMS Innovation Fund for Medical Sciences (No. 2017-I2M-1-010)。
文摘Excess accumulation of white adipose tissue(WAT) causes obesity which is an imbalance between energy intake and energy expenditure. Obesity is a serious concern because it has been the leading causes of death worldwide, including diabetes, stroke,heart disease and cancer. Therefore, uncovering the mechanism of obesity and discovering anti-obesity drugs are crucial to prevent obesity and its complications. Browning, inducing white adipose tissue to brown or beige(brite) fat which is brown-like fat emerging in WAT, becomes an appealing therapeutic strategy for obesity and metabolic disorders. Due to lack of efficacy or intolerable side-effects, the clinical trials that promote brown adipose tissue(BAT) thermogenesis and browning of WAT have not been successful in humans. Obviously, more specific means still need to be developed to activate browning of white adipose tissue. In this review, we summarized seven kinds of natural products(alkaloids, flavonoids, terpenoids, long chain fatty acids, phenolic acids, else and extract) promoting white adipose tissue browning which can ameliorate the metabolic disorders, including obesity, dislipidemia, insulin resistance and diabetes. Since natural products are important drug sources and the browning property plays a significant role in not only obesity treatment but also in type 2 diabetes(T2 DM) improvement, natural products of inducing browning may be an irreplaceable drug discovery orientation for obesity, diabetes and even other metabolic disorders.
基金supported by the National Natural Science Foundation of China(31871731)the Key Technology Research and Development Program of Shandong,China(2019GNC106050)+1 种基金the China Agriculture Research System of MOF and MARA(CARS-37)the Key Technology Research and Development Program of Binzhou City,China(2019ZDYF010)。
文摘This study investigated the effects of grape seed extract(GSE)on fresh and cooked meat color and premature browning(PMB)in ground meat patties(85% beef and 15% pork back fat)packaged under high-oxygen modified atmospheres(HiOx-MAP).The GSE was added to patties at concentrations of 0,0.10,0.25,0.50 and 0.75 g kg^(-1).This study evaluated the surface color,pH,lipid oxidation,and total viable counts(TVC)of raw patties,and the internal color and pH of patties cooked to a temperature of 66 or 71℃ over 10-day storage at 4℃.Compared with the control(0 g kg^(-1) GSE),GSE improved the color stability(P<0.05)and significantly inhibited the lipid and myoglobin oxidation of raw patties from day 5 to 10,but GSE had no effect(P>0.05)on TVC.Patties containing 0.50 and 0.75 g kg^(-1) GSE cooked to 66℃ exhibited greater(P<0.05)interior redness than the control and reduced the PMB of cooked patties in the late storage stage.These results suggested that 0.50 and 0.75 g kg^(-1) GSE can improve fresh meat color and minimize PMB of HiOx-MAP patties.
文摘Huangguan pear (Pyrus bretschneideri Rehd cv. Huangguan) is a pear cultivar that rapidly developed in China. However, rapid postharvest browning appearing in fruit peel and core during storage and shelf life pose a challenge for their marketing. The potential for low temperature conditioning (LTC) treatment to inhibit peel browning and improve quality of Huangguan pears in storage and shelf life was investigated. Pears were treated at 8℃ - 9℃ for 1, 3, 6 and 9 d, respectively, physiological indexes, including peel and core browning, core breakdown, malondialdehyde (MDA) content and ethanol content were determined and quality in storage period and shelf life was evaluated in this paper. LTC treatment alleviated peel browning and core browning either in storage or shelf life remarkably;it also delayed the decline of firmness, total soluble solids and titratable acidity in storage to some extent, inhibited ethanol and MDA content both in storage and shelf life effectively and maintained juiciness and crispness of pear fruit in shelf life. These results showed that LTC can serve as an important tool for the regulation of Huangguan pears external and internal quality in storage and shelf life with economic benefits and LTC treatment for 6 d was the optimum condition in the present study.
基金supported by the National Natural Science Foundation of China (No. 81973535, No. 82274166)the Natural Science Foundation of Liaoning Province (No. 2023-BS-093)。
文摘Mulberry (Morus alba L.) leaf is a well-established traditional Chinese botanical and culinary resource. It has found widespread application in the management of diabetes. The bioactive constituents of mulberry leaf, specifically mulberry leaf flavonoids (MLFs), exhibit pronounced potential in the amelioration of type 2 diabetes (T2D). This potential is attributed to their ability to safeguard pancreatic β cells, enhance insulin resistance, and inhibit α-glucosidase activity. Our antecedent research findings underscore the substantial therapeutic efficacy of MLFs in treating T2D. However, the precise mechanistic underpinnings of MLF’s anti-T2D effects remain the subject of inquiry. Activation of brown/beige adipocytes is a novel and promising strategy for T2D treatment. In the present study, our primary objective was to elucidate the impact of MLFs on adipose tissue browning in db/db mice and 3T3-L1 cells and elucidate its underlying mechanism. The results manifested that MLFs reduced body weight and food intake, alleviated hepatic steatosis, improved insulin sensitivity, and increased lipolysis and thermogenesis in db/db mice. Moreover, MLFs activated brown adipose tissue (BAT) and induced the browning of inguinal white adipose tissue (IWAT) and 3T3-L1 adipocytes by increasing the expressions of brown adipocyte marker genes and proteins such as uncoupling protein 1 (UCP1) and beige adipocyte marker genes such as transmembrane protein 26 (Tmem26), thereby promoting mitochondrial biogenesis. Mechanistically, MLFs facilitated the activation of BAT and the induction of WAT browning to ameliorate T2D primarily through the activation of AMP-activated protein kinase (AMPK)/sirtuin 1 (SIRT1)/peroxisome proliferator-activated receptor-gamma coactivator 1α (PGC-1α) signaling pathway. These findings highlight the unique capacity of MLF to counteract T2D by enhancing BAT activation and inducing browning of IWAT, thereby ameliorating glucose and lipid metabolism disorders. As such, MLFs emerge as a prospective and innovative browning agent for the treatment of T2D.
文摘Twigs of 2-3-year-old Platanus occidentalis L. were used as experimental material to find the causes for the contamination and browning in the initial stages of tissue cultures. To compare the degree of browning of explants picked off from different growing seasons, the experimental material was excised from trees on each of the first ten days in January, March, May and July, 2006. The results indicated that the contamination and browning rates of the material cut off in January （14.2% and 30.6%, respectively） and March were somewhat lower than those in July. The pretreatment of soaking the explants in different anti-oxidants and absorbents at the same time could diminish some side effects. The pretreatment of using 10 g·L^-1 vitamin C reduced the contamination and brown- ing rate effectively. An orthogonal experiment showed that the optimal factor and level arrangement is 0.5 mg·L^-1BA, 2.0 g·L^-1 active carbon and 1.5 g·L^-1 PVP which resulted in a browning rate of only 16.5%. In general, sampling period, physical properties and pretreatment of explants are the main factors responsible for the contamination and browning of material in the initial stages of P. occidentalis tissue cultures.
基金supported by the National Natural Science Foundation of China(Nos.30672603&30901956)the "111 Project" from the Ministry of Education of China and the State Administration of Foreign Expert Affairs of China(No.11-2-07)+1 种基金Key Projects in the National Science&Technology Pillar Program during the Eleventh Five-Year Plan Period(2006BAI-09B05-6)Program for Changjiang Scholars and Innovative Research Team in University(IRT0973)
文摘In the storage of Radix Ophiopogonis, browning often happens to cause potential risk with regard to safety. Previously few reports investigate the browning of Radix Ophiopogonis. In this research, the causes and mechanisms of the browning of Radix Ophiopogonis were preliminarily elucidated. Content determination by high-performance liquid chromatogra- phy （HPLC） and spectrophotometry, enzyme activity determination by colorimetry, and morphological observation by electron mi- croscopy were performed in the present study. Uniform design and three-dimensional response surfaces were applied to investigate the relationship between browning and storage factors. The cortex cell wall of browned Radix Ophiopogonis was ruptured. Compared with the normal Radix Ophiopogonis, cellulase and polyphenol oxidase enzymes were activated, the levels of 5-hydroxymethylfurfural （5-HMF）, total sugars, and reducing sugars were increased, while the levels of polysaccharides and methylophiopogonanone A were de- creased in browned Radix Ophiopogonis. The relationship between the storage factors and degree of browning （Y） could be described by following correlation equation： Y= - 0.625 4 ＋ 0.020 84 × X3 ＋ 0.001 514×X1×x X2 - 0.000 964 4 × X2 × X3. Accompanied with browning under storage conditions, the chemical composition of Radix Ophiopogonis was altered. Following the activation of cellulase, the rupture of the cortex cell wall and the outflow of cell substances flowed out, which caused the Radix Ophiopogonis tissue to become soft and sticky. The main causes of the browning were the production of 5-HMF, the activation of polyphenol oxidase, Maillard reactions and enzymatic browning. Browning could be effectively prevented when the air relative humidity （HR）, temperature, and moisture content were under 25% RH, 12 ℃ and 18%, respectively.
基金supported by the National Natural Science Foundation of China[31872674]the Jilin Talent Development Foundation Grant[20200301018RQ]the Fundamental Research Funds for the Central Universities[CGZH202206].
文摘Obesity-induced type 2 diabetes is mainly due to excessive free fatty acids leading to insulin resistance.Increasing thermogenesis is regarded as an effective strategy for hypolipidemia and hypoglycemia.Ginsenoside is a natural active component in Panax ginseng C.A.Meyer,and some of them enhance thermogenesis.However,there are few studies on the mechanism and target of ginsenosides enhancing thermogenesis.Using thermogenic protein uncoupling protein 1(UCP1)-luciferase reporter assay,we identifi ed ginsenoside F1 as a novel UCP1 activator in the ginsenosides library.Using pull down assay and inhibitor interference,we found F1 binds toβ3-adrenergic receptors(β3-AR)to enhance UCP1 expression via cAMP/PKA/CREB pathway.We also investigated the ability of F1 on energy metabolism in obesity-induced diabetic mice,including body weight,body composition and energy expenditure.The results of proteomics showed that F1 signifi cantly up-regulated thermogenesis proteins and lipolytic proteins,but down-regulated fatty acid synthesis proteins.Ginsenoside F1 increased thermogenesis and ameliorated insulin resistance specifi cally by promoting the browning of white adipose tissue in obese mice.Additionally,ginsenoside F1 improves norepinephrine-induced insulin resistance in adipocytes and hepatocytes,and shows a stronger mitochondria respiration ability than norepinephrine.These fi ndings suggest that ginsenoside F1 is a promising lead compound in the improvement of insulin resistance.
基金the financial support from the Guangdong Provincial Agricultural Science and Technology Development and Resource Environmental Protection Management Project(Grant No.2022KJ116)the Guangdong Provincial Modern Agricultural Industrial Park Project of Lechang city Lingnan deciduous fruit(LCTJ2020078CS)+1 种基金Guangdong Provincial,Operation and maintenance project of germplasm resource nursery of deciduous fruit trees(Grant No.2022-NBH-00-010)Guangdong Province rural science and technology special correspondent project(Grant No.KTP-20210162).
文摘The preharvest internal browning of Nane plum fruit,with no visible effects on the appearance of the fruit,has become a serious problem in recent years in its production area in Guangdong Province,China.This study investigated the effects of environmental factors,including temperature,on Nane plum internal browning.Plum orchards at different elevations with different incidences of internal browning were selected.Using fruits with different internal browning incidence levels,the internal browning mechanism was analyzed with transcriptome and metabolome analyses.The results revealed decreased internal browning at high altitudes.Shading treatment significantly reduced internal browning,whereas bagging and insect-proof net-covering treatments significantly increased internal browning.Because bagging and net coverings increase the local ambient temperature,the findings suggest that high temperature is an important factor influencing the internal browning of Nane plum.The metabolome experiments showed that with increased internal browning,the levels of phenolic hydroxyls such as catechol increased,with simultaneous increases in hydrogen peroxide content and oxidase activity.It can be speculated that the oxidation of phenolic hydroxyl substances is the main cause of the preharvest browning of Nane plum.Transcriptome analysis revealed the increased expression of calcium signaling-related and downstream effector genes and indicated an important role of calcium in internal browning,possibly due to its increased content in the fruit.Further,with increasingly serious internal browning,genes related to photosynthesis were down-regulated,while genes related to senescence were up-regulated,thus suggesting the up-regulation of the process of cell senescence during internal browning.In conclusion,heat stress should be eliminated to reduce preharvest internal browning in Nane plum.
