不同贮藏年限老芒麦种胚线粒体抗氧化功能的变化规律

种子在自然贮藏过程中常常伴随着内部生理机能的恶化，线粒体作为种子内活性氧（reactive oxide species，ROS）产生的主要位点是最先遭到破坏的细胞器。为探讨不同贮藏年限对老芒麦种胚线粒体抗氧化功能的影响，本试验以室温贮藏0～4年的老芒麦种子为材料，分析比较其老化规律及种胚线粒体抗氧化特性的变化规律。结果表明：随着贮藏年限的延长，老芒麦种子发芽势、发芽率和种苗鲜重逐渐下降，死种子逐渐增多，种胚线粒体苹果酸脱氢酶（mitochondria malate dehydrogenase，MDH）、谷胱甘肽还原酶（glutathione reductase，GR）、单脱氢抗坏血酸还原酶（monodehydroascorbate reductase，MDHAR）活性逐渐下降，但在死种子中超氧化物歧化酶（superoxide dismutase，SOD）活性显著升高。此外，在贮藏过程中老芒麦种胚线粒体O₂^·-产生速率不断上升，而H₂O₂含量则呈现逐渐降低的趋势，表明线粒体中O₂^·-的积累与细胞氧化损伤密切相关。     

Effect of AIR on Inflammatory Reaction Infected by Brucella

In order to investigate the effect of AIR on inflammatory reaction infected by Brucellamelitensis (16M), the AIR domain of Tecpr1 gene of murine macrophages RAW264.7 were knocked down (I-A), overexpressed (O-A) and reversed (OA-IA). Using the chlorine fluorescein (DCFH-DA) as a probe, we detected the variation of ROS production and mitochondria distribution by confocal laser scanning microscopy. We observed the expression changes of NLRP3, ASC and Caspase-1 by qRT-PCR and the expression changes of IL-18,IL-1β and Caspase-1 in host cells by ELISA. The results showed that 16M could stimulate RAW264.7 cells to produce ROS by time-dependent pathway, and I-A group and O-A group showed more abnormal accumulation of mitochondrial. The results of qRT-PCR and ELISA suggested that it had effect on the expression levels of NLRP3, ASC,Caspase-1 and IL-18, IL-1β and Caspase-1 in cells of different groups. Those results indicated that with AIR gene deletion, the release amount of ROS changed, mitochondrial clustered abnormally, and AIR was closely related to the activation of inflammasomes and induction of inflammatory reactions.     

Betaine Alleviates Heat Stress-Induced Hepatic and Mitochondrial Oxidative Damage in Broilers

The aim of this study was to evaluate the effects of dietary betaine (BET) on growth performance, redox state, and related gene expression in broilers under heat stress (HS). A total of 144 21-day-old male broiler chickens with similar body weights were assigned randomly to three treatments with six replicates (eight chickens per replicate cage). Broilers in the control (CON) group were kept at thermoneutral (TN, 22±1°C) conditions and fed a basal diet until they were 42 days of age. Broilers in the other two groups (defined as HS and HS + BET) were exposed to HS (34±1°C, 8 h/day) and fed the basal diet without or with 1000 mg/kg BET, respectively. Rectal and cockscomb temperature of broilers was increased (P<0.05) in HS and HS + BET groups compared with the CON group, whereas there was no difference between HS and HS + BET groups. Dietary BET supplementation restored (P<0.05) average daily gain (ADG) and average daily feed intake (ADFI) of broilers and reversed (P<0.05) the increase in serum alanine transaminase (ALT) activity and malondialdehyde (MDA) content in the liver tissue of broilers under HS. The HS + BET group had higher (P<0.05) activities of superoxide dismutase (SOD) and glutathione peroxidase (GPX) in the liver tissue and mitochondria than the HS group, and the same pattern was observed for glutathione (GSH) and GSH/glutathione disulphide (GSSG) in the liver tissue. The decreased mRNA levels of GPX1 and uncoupling protein (UCP) in the liver induced by HS were restored by BET supplementation. In conclusion, dietary BET supplementation can alleviate HS-induced hepatic and mitochondrial oxidative damage of broilers by regulating mRNA expressions of GPX1 and UCP.     

紫花苜蓿种子吸胀期胚根线粒体AsA-GSH循环对低温胁迫的响应

为探究胚根线粒体抗坏血酸-谷胱甘肽(AsA-GSH)循环响应低温胁迫的抗氧化作用机制,以紫花苜蓿种子为材料,研究了不同温度(10和20℃)处理下发芽特性、不同吸胀时间(6、12和24 h)胚根线粒体AsA-GSH循环酶活性、抗氧化物以及过氧化氢(H₂O₂)含量的变化规律。结果表明,吸胀12和24 h后,10℃处理的胚根线粒体H₂O₂含量高于20℃。吸胀24 h期间,10℃处理的胚根线粒体谷胱甘肽还原酶(GR)活性均低于20℃。吸胀12和24 h后,10℃处理的胚根线粒体抗坏血酸(AsA)含量均低于20℃。10℃条件下吸胀24 h后,与20℃处理相比,胚根线粒体谷胱甘肽(GSH)含量显著降低(P<0.05)。苜蓿种子在10℃条件下吸胀萌发时,主要通过降低AsA-GSH循环中GR、单脱氢抗坏血酸还原酶(MDHAR)、过氧化物酶(POD)活性和AsA、GSH含量,使胚根线粒体内的H₂O₂积累,产生氧化损伤,继而影响种子萌发的正常进程。     

褪黑素对内毒素血症山羊肝细胞线粒体呼吸功能的影响

将48只健康山羊随机分为4组：对照组（A组）、内毒素（LPS）组（B组）、内毒素＋褪黑素（LPS＋MT）组（C组）、褪黑素（MT）组（D组）,在处理后第3 h和6 h提取肝细胞线粒体,采用Clark氧电极技术测定线粒体呼吸控制率（RCR）、磷氧比值（P/O）、氧化磷酸化效率（OPR）的变化,探讨了MT对LPS诱导的山羊内毒素血症机体线粒体呼吸功能的影响。结果显示,内毒素组山羊在第3 h和6 h的RCR、P/O、OPR显著低于对照组（P〈0.05）;应用褪黑素后,即内毒素＋褪黑素组第3 h的肝细胞线粒体RCR、P/O、OPR明显升高（P〈0.05）;褪黑素组第3 h的RCR明显高于对照组（P〈0.05）,而褪黑素组第3 h的P/O、OPR与对照组差异不显著（P〉0.05）。证实,山羊内毒素血症时线粒体的呼吸功能明显下降,褪黑素对肝细胞线粒体呼吸功能具有一定的保护作用。     

氮对低氧胁迫下樱桃根系抗氧化酶活性及线粒体功能的影响

 以‘吉塞拉5号’樱桃组培苗为试材, 研究短期低氧胁迫下氮对樱桃幼苗根系抗氧化酶活性 及线粒体功能的影响。通过溶氧调节仪人为控制营养液溶氧浓度为2 mg·L ^{- 1} , NO₃^- 浓度共设4个水平:0、7.5、15.0、22.5 mmol·L ^{- 1} , 以1 /2 Hoagland营养液正常低氧处理(NO₃^- 浓度7.5 mmol·L ^{- 1} ) 为对照。结果表明: 各处理SOD、POD、CAT酶活性均呈现先升高后降低的趋势。与对照相比, 营养液加氮处理的SOD、POD、CAT酶活性升高, 膜质过氧化程度减轻, 且氮浓度越大酶活性升高幅度越大, 而营养液缺氮处理的酶活性降低, 膜质过氧化程度加重; 营养液缺氮处理樱桃根系线粒体中的H₂O₂和MDA含量、O₂^-·生成速率升高, 而营养液加氮处理可降低O₂^-·的产生及MDA含量, 提高线粒体的氧化磷酸化水平, 保护樱桃根系线粒体膜的完整性, 对线粒体呼吸功能的破坏明显减轻, 且NO₃^- 离子浓度高时效果更好, 说明适当提高营养液中的氮素水平可以缓解低氧胁迫对樱桃根系的伤害。     

Inheritance pattern of chloroplast and mitochondrial genomes in artificial hybrids of Porphyra yezoensis (Rhodophyta)

ABSTRACT:   To investigate inheritance of chloroplasts and mitochondria (organelles) in the marine red alga Porphyra yezoensis , cleaved amplified polymorphic sequence (CAPS) profiles of the two strains, TU-2 and KGJ, as parental gametophytes and 44 hybrid sporophytes (i.e. female of TU-2 and male of KGJ) were examined. A carbamyl phosphate synthase small subunit gene ( carA ) and ribosomal protein S11 gene ( rps11 )-small subunit ribosomal RNA gene ( rns ) spacer region were used as molecular markers for the chloroplast and mitochondrial DNAs, respectively. Thirty-eight of 44 (86.4%) conchocelis colonies showed maternal banding patterns, five (11.4%) colonies showed biparental bands and one (2.2%) colony showed paternal bands in CAPS analyses both with chloroplast and mitochondrial markers. These results suggest that organelles of P. yezoensis are inherited uniparentally from the female parent.     

短高温对小麦花器官及旗叶的超微结构变化的直接影响

在春小麦花粉母细胞期和单核期进行短期高温杀雄处理后，用透射电子显微镜观察小麦花器官和旗叶的超微结构。结果表明：短期高温直接使小孢子和绒毡层细胞中线粒体等双层细胞器严重破坏，并且使绒毛层细胞膨胀与小孢子粘连。而胚囊的线粒体和旗叶片中的 纯粒体及叶绿体结构变化不明显。     

Mitochondrial NAD(P)-malic enzyme from herring skeletal muscle

Mitochondrial NAD(P)-dependent malic enzyme [EC 1.1.1.39, L-malate: NAD⁺ oxidoreductase (decarboxylating)] was purified from herring skeletal muscle to a specific activity of 8.2 mol/min/mg. The purification procedure involved chromatography on DEAE-cellulose, Red Agarose and a Sephacryl S-300 with a final recovery of 38% of enzyme activity. This enzyme catalyzes the oxidative decarboxylation of malate in the presence of either NAD or NADP in the presence of Mn²⁺. Some kinetic characteristics of this enzyme were determined. The pH optimum of activity is 7.0. ATP was shown to be a competitive inhibitor with malate. The inhibition by ATP displayed hyperbolic competitive kinetics with a K_i (ATP) of 0.28 mM in the presence of NAD and 0.75 mM in the presence of NADP. Fumarate reversed ATP inhibition.In vivo, regulation of NAD(P)-dependent malic enzyme might respond to changing levels of mitochondrial ATP and fumarate with the enzyme undergoing kinetic activation by an increase in the concentration of mitochondrial fumarate which could reverse enzyme inhibition by ATP.     

姜黄素的理化特性、抗氧化功能及其在肉鸡生产中的应用

姜黄素是从姜科植物姜黄中提取的一种多酚类活性物质,具有多种生物学功能.近几年,姜黄素作为天然抗氧化剂对机体抗氧化功能的影响引起了人们的广泛关注,其作为一种绿色、新型的饲料添加剂应用于肉鸡生产也成为了国内外的研究热点之一.本文主要介绍了姜黄素的理化性质、生物利用率、抗氧化功能及其在肉鸡生产中的应用现状.