Mango(Mangifera indica L.)is one of the main economic crops in Hainan,China,prized for its distinctive flavor and high nutritional value.It is also rich in health-promoting antioxidants such as vitamin C and flavonoid...Mango(Mangifera indica L.)is one of the main economic crops in Hainan,China,prized for its distinctive flavor and high nutritional value.It is also rich in health-promoting antioxidants such as vitamin C and flavonoids.Enhanced ultraviolet-B(UV—B)radiation,a growing global environmental concern,alters plant antioxidant systems,with increased flavonoid accumulation as a common adaptive response.However,its effects on mango fruit remain largely unexplored.To investigate the antioxidant responses of mango to enhanced UV-B radiation and identify key responsive flavonoid compounds and regulatory genes,we exposed‘Tainong 1’mango fruits growing under natural light to 96 kJ·m^(-2)·d^(-1)of UV-B radiation to simulate high UV-B conditions.Treated fruits were smaller in size and had a pulp of a more intense yellow colour.Further,malondialdehyde content in treated fruits was higher during the phase of rapid fruit enlargement.Additionally,treated fruits showed increased sugar-acid ratios,total phenol,total flavonoid,carotenoid,and ascorbic acid contents.Furthermore,they showed significantly enhanced antioxidant activity,as measured by the FRAP,ABTS,and DPPH assays.Extensive targeted metabolomic-analysis identified flavonoids as the largest category of compounds differentially expressed in treated and control groups.Quantitative metabolomics of flavonoids identified hyperoside,quercimeritrin,and(-)-catechin gallate as the key flavonoid metabolites responsive to UV-B treatment.Transcriptome analysis revealed an enrichment of the flavonoid biosynthesis pathway,with most associated differentially expressed genes showing upregulation.Furthermore,qRT-PCR analysis confirmed that the expression of the genes MiCHS7,MiCHI1,MiCHI2,MiFLS,MiF3H2,and MiF3H3 correlated with changes in key flavonoid metabolites.Indeed,correlation analysis indicated that MiCHS7,MiCHI1,MiFLS,and MiF3H3 are potential key genes involved in flavonoid accumulation under UV-B treatment.Thus,our study provides a theoretical basis for breeding for new resilient varieties and developing UV-B-resistant mango cultivation techniques.展开更多
Stroke and Alzheimer's disease are common neurological disorders and often occur in the same individuals.The comorbidity of the two neurological disorders represents a grave health threat to older populations.This...Stroke and Alzheimer's disease are common neurological disorders and often occur in the same individuals.The comorbidity of the two neurological disorders represents a grave health threat to older populations.This review presents a brief background of the development of novel concepts and their clinical potentials.The activity of glutamatergic N-methyl-D-aspartate receptors and N-methyl-D-aspartate receptor-mediated Ca^(2+)influx is critical for neuronal function.An ischemic insult induces prompt and excessive glutamate release and drastic increases of intracellular Ca^(2+)mainly via N-methyl-D-aspartate receptors,particularly of those at the extrasynaptic site.This Ca^(2+)-evoked neuronal cell death in the ischemic core is dominated by necrosis within a few hours and days known as acute excitotoxicity.Furthermore,mild but sustained Ca^(2+)increases under neurodegenerative conditions such as in the distant penumbra of the ischemic brain and early stages of Alzheimer's disease are not immediately toxic,but gradually set off deteriorating Ca^(2+)-dependent signals and neuronal cell loss mostly because of activation of programmed cell death pathways.Based on the Ca^(2+)hypothesis of Alzheimer's disease and recent advances,this Ca^(2+)-activated“silent”degenerative excitotoxicity evolves from years to decades and is recognized as a unique slow and chronic neuropathogenesis.The N-methyl-D-aspartate receptor subunit GluN3A,primarily at the extrasynaptic site,serves as a gatekeeper for the N-methyl-D-aspartate receptor activity and is neuroprotective against both acute and chronic excitotoxicity.Ischemic stroke and Alzheimer's disease,therefore,share an N-methyl-D-aspartate receptor-and Ca^(2+)-mediated mechanism,although with much different time courses.It is thus proposed that early interventions to control Ca^(2+)homeostasis at the preclinical stage are pivotal for individuals who are susceptible to sporadic late-onset Alzheimer's disease and Alzheimer's disease-related dementia.This early treatment simultaneously serves as a preconditioning therapy against ischemic stroke that often attacks the same individuals during abnormal aging.展开更多
海洋垃圾已引起国际社会的广泛关注,是当前环境领域热点问题之一.为揭示我国渤海近岸海域海洋垃圾的赋存特征及其分布规律,于2018年丰水期(8月)在辽东湾河口区海域布设6个长度为5~10 km的调查断面,利用拖网同时采集海面漂浮垃圾与海底垃...海洋垃圾已引起国际社会的广泛关注,是当前环境领域热点问题之一.为揭示我国渤海近岸海域海洋垃圾的赋存特征及其分布规律,于2018年丰水期(8月)在辽东湾河口区海域布设6个长度为5~10 km的调查断面,利用拖网同时采集海面漂浮垃圾与海底垃圾,初步调查辽东湾近岸海域海洋垃圾分布和组成特征,并对海洋垃圾来源进行了分析.结果表明:①辽东湾海面漂浮垃圾数量密度为67个km^2,质量密度为741 g km^2;海底垃圾数量密度为19个km^2,质量密度为2544 g km^2.②在所收集的各类海洋垃圾中,塑料类垃圾数量占比约为50.9%,其中海底塑料类垃圾数量占比(62.1%)明显高于海面漂浮塑料垃圾数量占比(37.5%).③由塑料垃圾形态特征和表面带有的标识判断,辽东湾近岸海域塑料垃圾主要是来源于生活塑料垃圾(84.9%)和渔业垃圾(15.1%).在此基础上,建议加强源头管理以减少塑料垃圾进入海洋,主要包括完善当前海洋垃圾分类方法、加强渔业塑料垃圾回收、提升公民保护海洋环境意识和制定国家海洋塑料垃圾行动计划等.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant No.32160677)the Hainan University Mango Research System.
文摘Mango(Mangifera indica L.)is one of the main economic crops in Hainan,China,prized for its distinctive flavor and high nutritional value.It is also rich in health-promoting antioxidants such as vitamin C and flavonoids.Enhanced ultraviolet-B(UV—B)radiation,a growing global environmental concern,alters plant antioxidant systems,with increased flavonoid accumulation as a common adaptive response.However,its effects on mango fruit remain largely unexplored.To investigate the antioxidant responses of mango to enhanced UV-B radiation and identify key responsive flavonoid compounds and regulatory genes,we exposed‘Tainong 1’mango fruits growing under natural light to 96 kJ·m^(-2)·d^(-1)of UV-B radiation to simulate high UV-B conditions.Treated fruits were smaller in size and had a pulp of a more intense yellow colour.Further,malondialdehyde content in treated fruits was higher during the phase of rapid fruit enlargement.Additionally,treated fruits showed increased sugar-acid ratios,total phenol,total flavonoid,carotenoid,and ascorbic acid contents.Furthermore,they showed significantly enhanced antioxidant activity,as measured by the FRAP,ABTS,and DPPH assays.Extensive targeted metabolomic-analysis identified flavonoids as the largest category of compounds differentially expressed in treated and control groups.Quantitative metabolomics of flavonoids identified hyperoside,quercimeritrin,and(-)-catechin gallate as the key flavonoid metabolites responsive to UV-B treatment.Transcriptome analysis revealed an enrichment of the flavonoid biosynthesis pathway,with most associated differentially expressed genes showing upregulation.Furthermore,qRT-PCR analysis confirmed that the expression of the genes MiCHS7,MiCHI1,MiCHI2,MiFLS,MiF3H2,and MiF3H3 correlated with changes in key flavonoid metabolites.Indeed,correlation analysis indicated that MiCHS7,MiCHI1,MiFLS,and MiF3H3 are potential key genes involved in flavonoid accumulation under UV-B treatment.Thus,our study provides a theoretical basis for breeding for new resilient varieties and developing UV-B-resistant mango cultivation techniques.
基金supported by National Health Institute(NIH)grant NS099596(to LW and SPY),NS114221(to LW and SPY)Veterans Affair(VA)SPiRE grant RX003865(to SPY)+1 种基金supported by the O.Wayne Rollins Endowment Fund(to SPY)John E.Steinhaus Endowment Fund(to LW)。
文摘Stroke and Alzheimer's disease are common neurological disorders and often occur in the same individuals.The comorbidity of the two neurological disorders represents a grave health threat to older populations.This review presents a brief background of the development of novel concepts and their clinical potentials.The activity of glutamatergic N-methyl-D-aspartate receptors and N-methyl-D-aspartate receptor-mediated Ca^(2+)influx is critical for neuronal function.An ischemic insult induces prompt and excessive glutamate release and drastic increases of intracellular Ca^(2+)mainly via N-methyl-D-aspartate receptors,particularly of those at the extrasynaptic site.This Ca^(2+)-evoked neuronal cell death in the ischemic core is dominated by necrosis within a few hours and days known as acute excitotoxicity.Furthermore,mild but sustained Ca^(2+)increases under neurodegenerative conditions such as in the distant penumbra of the ischemic brain and early stages of Alzheimer's disease are not immediately toxic,but gradually set off deteriorating Ca^(2+)-dependent signals and neuronal cell loss mostly because of activation of programmed cell death pathways.Based on the Ca^(2+)hypothesis of Alzheimer's disease and recent advances,this Ca^(2+)-activated“silent”degenerative excitotoxicity evolves from years to decades and is recognized as a unique slow and chronic neuropathogenesis.The N-methyl-D-aspartate receptor subunit GluN3A,primarily at the extrasynaptic site,serves as a gatekeeper for the N-methyl-D-aspartate receptor activity and is neuroprotective against both acute and chronic excitotoxicity.Ischemic stroke and Alzheimer's disease,therefore,share an N-methyl-D-aspartate receptor-and Ca^(2+)-mediated mechanism,although with much different time courses.It is thus proposed that early interventions to control Ca^(2+)homeostasis at the preclinical stage are pivotal for individuals who are susceptible to sporadic late-onset Alzheimer's disease and Alzheimer's disease-related dementia.This early treatment simultaneously serves as a preconditioning therapy against ischemic stroke that often attacks the same individuals during abnormal aging.
文摘海洋垃圾已引起国际社会的广泛关注,是当前环境领域热点问题之一.为揭示我国渤海近岸海域海洋垃圾的赋存特征及其分布规律,于2018年丰水期(8月)在辽东湾河口区海域布设6个长度为5~10 km的调查断面,利用拖网同时采集海面漂浮垃圾与海底垃圾,初步调查辽东湾近岸海域海洋垃圾分布和组成特征,并对海洋垃圾来源进行了分析.结果表明:①辽东湾海面漂浮垃圾数量密度为67个km^2,质量密度为741 g km^2;海底垃圾数量密度为19个km^2,质量密度为2544 g km^2.②在所收集的各类海洋垃圾中,塑料类垃圾数量占比约为50.9%,其中海底塑料类垃圾数量占比(62.1%)明显高于海面漂浮塑料垃圾数量占比(37.5%).③由塑料垃圾形态特征和表面带有的标识判断,辽东湾近岸海域塑料垃圾主要是来源于生活塑料垃圾(84.9%)和渔业垃圾(15.1%).在此基础上,建议加强源头管理以减少塑料垃圾进入海洋,主要包括完善当前海洋垃圾分类方法、加强渔业塑料垃圾回收、提升公民保护海洋环境意识和制定国家海洋塑料垃圾行动计划等.
