低温胁迫下植物MAPK 反应及LeMAPKs 功能的生物信息学预测

促分裂原活化蛋白激酶(mitogen-activated protein kinases,MAPK/MPK)级联是植物响应外界环境变化的重要信号传导途径。MAPK 级联参与植物低温信号转导过程并在此过程中起信号放大和传递的中枢作用。目前人们在植物中发现多种参与低温胁迫过程的MAPK。本文介绍了植物中与低温胁迫相关的MAPK 研究进展,并通过生物信息学的方法对番茄中具有相关功能的番茄促分裂原活化蛋白激酶(LeMAPKs)进行预测,为进一步研究MAPK级联在植物低温信号转导过程中的作用机制提供参考。     

姜黄素提高PC12细胞的抗氧化能力

目的:以低分化和高分化大鼠肾上腺嗜铬细胞瘤(pheochromocytoma,PC 12)细胞为研究对象,探究姜黄素抗氧化能力及其可能的作用机理.方法:通过噻唑蓝法测定PC12细胞的相对增殖率,然后确定姜黄素的作用浓度及作用时间;采用2,2'-联氮双(3-乙基苯并噻唑啉-6-磺酸)二铵盐法及铁离子还原/抗氧化能力法测定...     

南瓜、山药、葛根和桑叶提取物复方对四氧嘧啶模型小鼠的降血糖作用

目的：研究南瓜、山药、葛根和桑叶提取物复方对四氧嘧啶糖尿病模型小鼠的降血糖作用。方法：以四 氧嘧啶诱导建立糖尿病小鼠模型,实验保留10 只小鼠作为正常对照组,并将建模成功的小鼠随机分为模型组、阳 性组（阿卡波糖,200 mg/kg mb）、植物提取物复方低、高剂量组（12、36 g/kg mb,以原料干质量计）。连续灌 胃给药4 周,研究植物提取物复方对糖尿病小鼠体质量及饮食饮水量、空腹血糖浓度、肝糖原含量、糖化血清蛋白 （glucosylated serum protein,GSP）浓度、糖化血红蛋白（glycosylated hemoglobin,GHb）相对含量和抗氧化指标 的影响。结果：植物提取物复方中的主要有效成分为南瓜多糖、山药多糖和葛根素,含量分别为（0.93±0.04）、 （1.01±0.06）、（0.28±0.01）g/100 g（以原料干质量计）。干预4 周后,与模型组相比,植物提取物复方组小鼠 体质量、肝糖原含量显著增加,饮食饮水量、空腹血糖浓度、GSP浓度和GHb相对含量明显降低,胰岛素敏感性增 强,且高剂量效果优于低剂量。植物提取物复方组较模型组总抗氧化能力和超氧化物歧化酶活力明显升高,丙二醛 含量显著降低,表现出改善小鼠氧化应激的作用。结论：南瓜、山药、葛根和桑叶提取物复方能够显著降低四氧嘧 啶性糖尿病模型小鼠血糖浓度,有效改善氧化应激状态。     

植物多酚缓解运动疲劳作用机制研究进展

疲劳是机体能量协调紊乱产生的现象,长时间运动疲劳会引发相关的疾病.多酚具有明显的生物活性,如抗氧化、抗肿瘤等.目前多酚已被证实具有抗疲劳作用,可通过调节AMPK信号通路调节氧化应激、能量代谢和炎症以及底物代谢发挥缓解运动疲劳的功效.本文对运动疲劳产生及机制、抗疲劳多酚类物质的来源及其缓解疲劳的作用机制进行了系统综述,旨...     

番茄促分裂素原活化蛋白激酶的研究进展与生物信息学分析

促分裂素原活化蛋白激酶(mitogen-activated protein kinases,MAPK、MPK 或MK)级联是一种广泛存在于真核生物中的信号传导途径。同动物和酵母类似,植物细胞的MAPK 级联也是由MAPKKK (MEKK, MKKK),MAPKK (MEK,MKK),MAPK 三个级别的激酶对其下游蛋白的磷酸化构成的,最终对细胞生长、发育及抗性等过程中的效应分子进行调控。本文介绍了番茄目前的测序情况,以及番茄(Lycopersicon esculentum)MAPK(LeMAPK,LeMPK)的研究进展,根据MAPK 序列在进化过程中的保守性,用模式植物拟南芥(Arabidopsis thaliana)MAPK(AtMAPK,AtMPK)基因序列在番茄的转录序列中搜索,得到18 个LeMAPK 条目,其中两条是新的LeMAPK,并与AtMAPK 进行比对和归类。     

Alleviation of salt stress in wheat seedlings by mammalian sex hormones

BACKGROUND: Salinity is one of the most serious constraints facing agriculture today. Some mechanical, chemical and biological approaches are being pursued to cope with soil salinity. Although exogenously treated mammalian sex hormones (MSHs), progesterone, β‐estradiol and androsterone, activate significant effects in various biological aspects in plants growing under normal conditions, there is no report investigating their effects on plants growing under salt stress. The present study aimed to investigate whether MSHs could alleviate the destructive effect of salt stress on wheat seedlings and thereby increase their salt tolerance. Wheat leaves were sprayed with 10^?6, 10^?8 and 10^?10 mol L^?1 concentrations of MSH on the ninth day after sowing. MSH‐treated seedlings (10‐day‐old seedlings) were subjected to salt stress for 5 days (between days 10 and 15). RESULTS: At all the concentrations tested, MSH treatment provided a significant protection against to detrimental effects of salt stress in wheat seedlings. It improved dry weight, sugar, proline, protein, chlorophyll and glutathione contents in comparison to salinity alone. Similarly, superoxide dismutase, peroxidase, catalase, ascorbate peroxidase and nitrate reductase activities also were augmented by MSH treatment. On the other hand, increases in lipid peroxidation level, superoxide production and hydrogen peroxide content arising from salt treatment were reduced by MSH treatment. The highest salt tolerance was obtained at the concentrations of 10^?6 mol L^?1 for progesterone and 10^?8 mol L^?1 for β‐estradiol and for androsterone. CONCLUSION: MSHs could be used effectively to protect wheat seedlings from the destructive effects of salt stress by stimulating both enzymatic and non‐enzymatic antioxidant mechanism and by promoting levels of osmotic protectants such as proline and sugars resulting in osmotic adjustment, carbon storage and radical scavenging in plants. Copyright © 2011 Society of Chemical Industry     

Antioxidant Modulation of F2-Isoprostanes in Humans: A Systematic Review

F2-isoprostanes are a biomarker of lipid peroxidation, and their measurement has emerged as a reliable approach to assess oxidative stress. However, dietary intervention studies in humans have provided contrasting results following supplementation with antioxidant-rich foods or supplements. In this paper, we have systematically reviewed the evidence about the effect of supplementation with antioxidant-rich foods and galenic antioxidants on isoprostanes levels in humans. Moreover, the association with nonenzymatic antioxidant capacity (NEAC), a biomarker of endogenous antioxidant status, has also been investigated.

MEDLINE database was searched using the terms “(isoprostane* OR isoP OR iso-PGF OR epi-PGF) AND (intervention* OR consumption* OR administration* OR supplementation*),” with limits activated “humans” and “English.” Abstracts and full texts were screened, from which were selected human intervention studies reporting isoprostanes measurement in biological fluids. The total of the studies carried out with antioxidant-rich foods and antioxidant galenic supplements was 113, reporting 154 interventions. Results suggest that dietary antioxidants modulate successfully the levels of isoprostanes in less than 45% of the interventions. A correspondence between the effect on isoprostane and NEAC has been evidenced, and this correspondence suggests the importance of measuring different biomarkers to obtain a better outline of the redox events following supplementation.     

黄酮类化合物干预糖尿病视网膜病变的研究进展

糖尿病视网膜病变是糖尿病患者中最常见的微血管并发症,也是全世界造成失明的主要原因之一。人体内活性氧过量产生导致的氧化损伤是糖尿病视网膜病变的主要发病机制。黄酮类化合物普遍存在于植物膳食中,具有抗氧化、抗炎、降血糖、清除自由基等多种生理活性。近年来,越来越多的研究表明,黄酮类化合物对糖尿病视网膜病变有显著的干预效果。本文综述了近年来国内外对黄酮类化合物抗糖尿病视网膜病变的研究进展,以期为黄酮类化合物的进一步开发和应用提供理论参考和研究思路。     

植物多糖对肾损伤干预效果及作用机制研究进展

植物多糖作为一种食物来源,往往以膳食纤维的形式对人体产生有益的影响,有效抗肾脏损伤是其重要的作用之一。目前对于肾脏病的预防与治疗主要以药物为主,对于保健品、功能性食品等辅助治疗肾脏病的研究报道较少。该文从食品角度简述了植物多糖对糖尿病肾损伤、缺血再灌注肾损伤、重金属肾损伤、化学性肾损伤和药物性肾损伤的干预效果,并从直接和间接两个方面着重探讨了多糖发挥抗肾损伤的作用机制,进一步对植物多糖抗肾损伤的研究方向进行展望,以期为研发干预肾损伤的功能性食品提供参考。     

Effect of nitrogen nutrition and water regime on abscisic,phaseic and dihydrophaseic acid metabolism in leaves of field-grown kale (Brassica oleracea): Consequences for plant growth and crop yield

Relationships between yield and the accumulation and metabolism of abscisic acid were examined on a kale (Brassica oleracea L) crop grown during a dry summer in the UK under different degrees of water and/or N stress. Measurements were made on both irrigated and unirrigated plants given three rates of N fertiliser, incorporated in up to three different ways in the soil. Growth of the crop was severely restricted in all treatments where irrigation and N fertiliser were withheld. Substantial production and metabolism of abscisic acid occurred in all treatments during growth, with dihydrophaseic acid the major product. Irrigation treatments had no consistent significant effect on the concentrations of either abscisic acid or any of its metabolites, although individual N treatments did show small concentration increases for some of the compounds on the unirrigated plots. By comparison, the N treatments had large effects on the accumulation of abscisic acid and of dihydrophaseic acid (both as free acid and as its glucoside). The concentrations of each of these forms increased significantly with the amount of N applied, the response being modified by a small but significant effect of method of fertiliser incorporation due mainly to its influence on the pattern of N availability during the growing season. However, the concentrations of abscisic acid and some of the metabolites were only correlated with yield in the irrigated treatment. These results suggest that neither the accumulation of abscisic acid nor the ability of the plants to metabolise it were major factors in restricting the growth of kale under either water- or N-stressed conditions in the U K.     

湖南德夯风景名胜区油脂植物资源调查及分析

通过前期野外调查、标本数据整理以及文献查阅,对湖南省德夯风景名胜区油脂植物资源进行统计分析。结果表明：该区油脂植物共有90科239属429种;含种数在15种以上的优势科有8个,分别是豆科、蔷薇科、樟科、大戟科、忍冬科、百合科、卫矛科和芸香科;含种数在10种以上的优势属有2个,分别是荚蒾属、山胡椒属;生活习性以木本为主;该区油脂植物区系地理成分科级水平上以泛热带分布和世界分布为主,属级水平上以泛热带分布和北温带分布为主,种级水平上主要集中在东亚分布和中国特有分布。该区油脂植物种类丰富,用途广泛,含油量在40%以上的有40种（18科22属）,资源开发与利用潜力较大。德夯风景名胜区与湘西地区整体油脂植物资源特征一致,与武功山、井冈山、庐山、壶瓶山油脂植物区系地理成分特征大体一致。     

Can environmental dust from silo area allow the development of stored product insects?

Dust derived from food processing can accumulate in places difficult to reach, where stored-product pests could thrive. The purpose of this work was to verify the development of Plodia interpunctella, Ephestia kuehniella, and Tribolium castaneum in dust collected on pipes and beams (15 m and 7.5 m) in a silo area of a pasta industry. Proximate analyses showed a higher metal content in the dust collected at the two different heights than semolina, including the presence of chrome, cobalt, arsenic, and lead. Particle size distribution analysis showed that in the two samples of dust the highest percentage was constituted by particle sizes smaller than 106 μm. The tests were carried out by using two quantities 4 g or 0.15 g of dust (corresponding to 3 mm and 0.1 mm), at controlled conditions. Fifty larvae, 0–24 h old, of each species, were used for each dust, semolina, and thickness test. The number of emerged adults was assessed daily. T. castaneum developed on all the tested substrates, despite the high content of metals and the small particle size in the environmental dust. A significant interaction between diet and thickness of the layer was observed, but thickness had a stronger influence than diet. Moreover, light filth analysis detected a large number of fragments of Tribolium sp. in dust collected at a different height. Dust was unsuitable for the development of moths; only two E. kuehniella adults emerged from 3-mm-deep dust collected at 15 m, and development lasted more than 90 d.     

几种豆科植物抗菌肽的生物信息学预测与分析

植物抗菌肽是存在于植物组织细胞中的一类对于对外来侵害有防御作用的小分子蛋白,可抑制或杀伤多种细菌和真菌。随着人们健康意识的提高以及技术手段的进步,植物来源抗菌肽的发掘和应用逐渐成为食品开发领域的重要研究方向。该试验从蛋白数据库中筛选了7种豆科植物的抗菌肽,并对其蛋白序列进行了比对和系统进化树分析,结合生物信息学研究工具对豆科植物抗菌肽的疏水性、拓扑结构域、蛋白空间结构和亚细胞定位进行了预测和分析。结果表明,7种豆科植物抗菌肽序列相似度达到71.94%,均具有8个半胱氨酸保守位点;豆科植物抗菌肽为碱性膜结合蛋白,分布于液泡膜、细胞核膜或者细胞膜上;其3D结构均由一组β-折叠和一个α-螺旋组成,与硫堇、植物防卫素蛋白结构相似。     

Analysis of low molecular weight plant phenolics by thermospray liquid chromatography/mass spectrometry

High performance liquid chromatography-mass spectrometry using a thermospray interface and discharge ionisation has been conducted on a group of plant phenolic standards and on a wheat straw acid hydrolysate. Protonated molecules, [M + H]⁺, were observed for the phenolic standards and it was possible to identify several phenolic compounds in the hydrolysate. These results indicate that thermospray HPLC/MS has potential as a technique for determining the presence of useful marker compounds which are indicative of the progress of the lignification during plant growth.     

双丰系列甜菜品种（系）产量、含糖与农艺性状的灰色关联度分析

利用灰色系统理论对双丰系列甜菜品种（系）有关甜菜15个农艺性状与产量、含糖率及产糖量的关联度进行了研究分析,结果表明,甜菜植物学株高农艺性状与甜菜产量、含糖及产糖量有较强关联性,关联系数分别为0．9697,排第3位、0．9766,排第7位、0．9701,排第3位,并提出增加甜菜“相对株高”植物学特征及测量方法,甜菜“相对株高”与“株高”进行比值,把传统的甜菜株型类型的定序型数据变为定距型数据即角度数字量化的观点。     

益生菌对消化道胃酸和胆盐胁迫的应激机理

益生菌进入人体消化道后,会遇到高酸及胆盐等不利益生菌存活的胁迫环境。酸和胆盐胁迫可使益生菌的活性下降,影响益生功能的发挥。亚致死剂量的酸或胆盐胁迫可以提高益生菌的耐受力,有助于益生菌在消化道中的存活。因此,研究益生菌酸胁迫及胆盐胁迫应激机理具有非常重要的意义。本文主要综述益生菌酸胁迫和胆盐胁迫可能的机理,并对未来的研究方向进行探讨。