福建假马齿苋属的初步研究

本文报道了福建省3种假马齿苋属植物:麦花草、假马齿苋和匍匐假马齿苋,其中匍匐假马齿苋为我国新记录的归化植物,新近发表的田玄参是该种的同物异名,田玄参属相应地应归并入假马齿苋属。同时,还纠正了国内有关假马齿苋学名和文献引证中的错误。     

假马齿苋的组织培养

1植物名称假马齿苋[Bacoba monnieri（L．）Wettst．],又名白花猪母菜、白线草、蛇鳞菜。 2材料类别茎尖。     

外源硫对镉胁迫下马齿苋光合性状和矿质元素吸收的影响

从光合反应系统揭示外源硫(S)诱导马齿苋镉(Cd)耐受性的生理机制,为外源S缓解重金属毒害提供理论依据.采用营养液培养,研究外源S供体(NH4)2SO4对100 mg/L Cd胁迫下马齿苋叶片光合色素、光合特性、叶绿素荧光参数和矿质营养元素的影响.结果表明,Cd胁迫可显著降低马齿苋叶片中叶绿素a和叶绿素b含量;净光合速率、蒸腾速率、气孔导度均显著降低,而胞间二氧化碳浓度上升,表明非气孔因素是Cd胁迫诱导马齿苋光合抑制的主要因素;同时,PSⅡ实际光化学效率(ФPSII)、电子传递效率(J)、化学猝灭系数(qP)显著下降,而非化学猝灭系数(qN)显著上升,表明Cd胁迫影响马齿苋PSⅡ反应系统的正常运行.外施400 mg/L(NH4)2SO4显著提高马齿苋叶片叶绿素a含量、叶绿素b含量和叶绿素a/b比值,增强马齿苋叶片光合作用和PSⅡ原初光化学反应量子效率.对5种与光反应系统密切相关的矿质元素含量进行分析发现,Cd处理显著增加马齿苋叶片中的Ca和Fe含量,显著抑制马齿苋对Mg、Mn和Cu的吸收.Cd胁迫下马齿苋叶片的变黄与Mg、Mn的亏缺有关,而与Fe缺乏无关;添加外源S可显著提升马齿苋叶片中Ca、Mg、Fe、Cu和Mn含量,从而增强Cd胁迫下马齿苋叶片的PSII反应系统功能.     

马齿苋与人体健康

马齿苋为马齿苋科1年生肉质草本野生植物,含有多种营养物质、以及人体所需的11种常量元素和4种微量元素,具有药用价值：马齿苋素有“绿色天然抗生素”的美称：经常食用马齿苋,对促进人体健康和增强体质等大有裨益。     

NaCl胁迫对马齿苋光合作用及叶绿素荧光特性的影响

以马齿苋为材料,采用温室盆栽法研究了14 d NaCl胁迫处理对其幼苗生长、光合作用和叶绿素荧光特性的影响.结果显示:(1)马齿苋幼苗的鲜重和株高在25 mmol·L-1 NaCl胁迫时与对照无显著差异,但其随着NaCl浓度的继续增加均显著降低,且其生物量受到的抑制早于株高.(2) NaCl胁迫下,马齿苋幼苗叶片净光合速率(Pn)降低,胞间二氧化碳浓度(C1)增大,且两者的变化幅度随着NaCl浓度增加而增大.(3)NaCl胁迫下,马齿苋幼苗叶片的初始荧光(F0)、最大荧光(Fm)、可变荧光(Fv)、恒态荧光(Fs)、恒态荧光与初始荧光差值(△F0)、PSⅡ潜在光化学效率(Fv/Fo)和PSⅡ最大光化学效率(Fv/Fm)均降低,叶片光化学荧光猝灭系数(qP)也在NaCl胁迫下降低,而非光化学荧光猝灭系数(NPQ)则上升;在0～50 mmol·L-1NaCl胁迫下,幼苗叶片各荧光参数下降幅度小于其他高浓度NaCl胁迫.研究表明,在NaCl胁迫条件下,马齿苋幼苗叶片的光合作用受光抑制伤害,但在低浓度NaCl下能够较多地将光能用于光化学反应,光抑制程度较低,保持了较高的净光合速率,明显减轻盐胁迫对植株生长的影响,表现出一定的耐盐性.     

马齿苋的组织培养与快速繁殖

马齿苋又名长命菜 ,长寿菜 ,为马齿苋科 1年生肉质草本植物。全草入药 ,具清热、凉血、解毒之功效 ,用于湿热泄泻、疔疮肿毒、蛇虫咬伤、痔疮肿痛、湿疹等。据现代医学研究报道 ,马齿苋中含有较高浓度的去甲肾上腺素 (每 g鲜品含量达 2 .5 mg) ,对糖尿病具有食疗作用 ;含有 ω- 3脂肪酸 ,对心血管有保护作用 ;含有较丰富的铜元素 (每 g干品含 2 1μg) ,可作为白癜疯患者和因缺铜元素而造成白发的患者的辅助食疗菜肴 ;还含有大量的钾盐 ,对维持心肌功能、参与细胞新陈代谢 ,维持渗透压 ,维持神经肌肉正常功能等 ,具有良好的保健作用。作为野…     

保健植物马齿苋

马齿苋(Portulaca oleracea L)又名马踏菜,麻绳菜,见于路旁,园圃、田间等湿地向阳处,遍布全国各地,生长很快,繁殖极易,是人们喜食的野蔬菜。马齿苋含有丰富的去甲肾上腺素,能预防和治疗糖尿病;又因含有 W—3脂肪酸,有保护心血管的功能,还能预防和治疗矽肺,及乌须黑发之功效。因此,有较高的药用价值和食用价值,且资源又极其丰富,可以变废为宝,开发利用。     

10个马齿苋类型的脂肪酸和草酸含量分析

该研究采用气相色谱和比色法测定了10种不同来源马齿苋茎、叶中的脂肪酸和草酸含量。结果表明:(1)脂肪酸和草酸在10个不同类型马齿苋茎、叶中的含量均表现出一定的差异显著性。(2)与叶片相比,茎中的脂肪酸含量相对较低;马齿苋茎、叶中以多元不饱和脂肪酸为主;共测出两种多元不饱和脂肪酸,分别是亚麻酸(ω-3脂肪酸)和亚油酸(ω-6脂肪酸);不同类型马齿苋叶片和茎中ω-3和ω-6脂肪酸分别占脂肪酸总量的62.71%~70.91%和9.30%~13.31%,以及26.04%~36.02%和31.61%~43.19%,‘金湖’‘南阳’马齿苋叶片和‘金湖’马齿苋茎中!-3脂肪酸含量显著高于其他类型;国产马齿苋类型,尤其是茎中的!-6/!-3比例明显小于国外马齿苋类型。(3)马齿苋茎中的草酸含量明显高于叶;除‘山东’‘Iran’和‘Pakistan’马齿苋茎中的草酸显著积累外,其他类型马齿苋茎中的草酸含量差异不显著。因此,马齿苋适宜早采收;‘金湖’和‘南阳’,尤其是‘金湖’类型的马齿苋是一种值得研究和推荐的马齿苋类型。     

马齿苋多糖对细胞存活率的影响及其毒性测定方法的比较研究

本文采用三种常用的细胞毒性试验方法(四甲基偶氮唑盐方法、中性红染料摄取法和乳酸脱氢酶释放法)评价马齿苋多糖抑制3T3-L1前脂肪细胞增殖的敏感性。结果显示,在一定浓度(0.01~0.50 mg/m L)和时间(1~5 d)范围内,马齿苋多糖具有抑制3T3-L1前脂肪细胞增殖作用,且呈浓度和时间依存关系。MTT法和LDH法在马齿苋多糖(0.01 mg/m L)处理3T3-L1细胞1 d时,细胞增殖率明显低于对照组(P0.01),NRU法在马齿苋多糖处理3 d时,细胞增殖率明显低于对照组(P0.05)。但当马齿苋浓度增加到0.5 mg/m L、处理时间延长至5 d时,细胞出现明显的固缩、漂浮和裂解等毒性作用。MTT法和LDH法较NRU法更为敏感,马齿苋多糖主要影响3T3-L1前脂肪细胞的膜完整性和线粒体功能。     

马齿苋的营养成份分析及其开发利用

马齿苋 (ＰｏｒｔｕｌａｃａｏｌｅｒａｃｅａＬ .) ,别名马齿菜 ,为马齿苋科一年生草本植物 ,分布在全国各地 ,夏、秋二季采收 ,主要以野生为主 ,少有人工栽培。马齿苋既是一种药用植物 ,又是一种可供开发利用、具有广阔前景的经济植物。本文主要对其蛋白质、微量元素、氨基酸等含量进行了分析研究。1材料和方法1 .1材料马齿苋于五月份采自长沙天心区 ,去根后 ,用自来水洗净泥土 ,去除附在马齿苋上的杂质 ,再用蒸馏水冲洗 2～ 3次 ,将其晾干 ,放 80℃恒温箱中干燥 2小时 ,用玛瑙研钵捣碎后放干燥器中备用。1 .2方法1 .2 .1微量元素的测定　…     

Effects of actinobacteria on plant disease suppression and growth promotion

Biological control and plant growth promotion by plant beneficial microbes has been viewed as an alternative to the use of chemical pesticides and fertilizers. Bacteria and fungi that are naturally associated with plants and have a beneficial effect on plant growth by the alleviation of biotic and abiotic stresses were isolated and developed into biocontrol (BCA) and plant growth-promoting agents (PGPA). Actinobacteria are a group of important plant-associated spore-forming bacteria, which have been studied for their biocontrol, plant growth promotion, and interaction with plants. This review summarizes the effects of actinobacteria as BCA, PGPA, and its beneficial associations with plants.     

Use of nitrogen-fixing bacteria as biofertiliser for non-legumes: prospects and challenges

The potential of nitrogen-fixing (NF) bacteria to form a symbiotic relationship with leguminous plants and fix atmospheric nitrogen has been exploited in the field to meet the nitrogen requirement of the latter. This phenomenon provides an alternative to the use of the nitrogenous fertiliser whose excessive and imbalanced use over the decades has contributed to green house emission (N(2)O) and underground water leaching. Recently, it was observed that non-leguminous plants like rice, sugarcane, wheat and maize form an extended niche for various species of NF bacteria. These bacteria thrive within the plant, successfully colonizing roots, stems and leaves. During the association, the invading bacteria benefit the acquired host with a marked increase in plant growth, vigor and yield. With increasing population, the demand of non-leguminous plant products is growing. In this regard, the richness of NF flora within non-leguminous plants and extent of their interaction with the host definitely shows a ray of hope in developing an ecofriendly alternative to the nitrogenous fertilisers. In this review, we have discussed the association of NF bacteria with various non-leguminous plants emphasizing on their potential to promote host plant growth and yield. In addition, plant growth-promoting traits observed in these NF bacteria and their mode of interaction with the host plant have been described briefly.     

Terpenoid biomaterials

Terpenoids (isoprenoids) encompass more than 40 000 structures and form the largest class of all known plant metabolites. Some terpenoids have well-characterized physiological functions that are common to most plant species. In addition, many of the structurally diverse plant terpenoids may function in taxonomically more discrete, specialized interactions with other organisms. Historically, specialized terpenoids, together with alkaloids and many of the phenolics, have been referred to as secondary metabolites. More recently, these compounds have become widely recognized, conceptually and/or empirically, for their essential ecological functions in plant biology. Owing to their diverse biological activities and their diverse physical and chemical properties, terpenoid plant chemicals have been exploited by humans as traditional biomaterials in the form of complex mixtures or in the form of more or less pure compounds since ancient times. Plant terpenoids are widely used as industrially relevant chemicals, including many pharmaceuticals, flavours, fragrances, pesticides and disinfectants, and as large-volume feedstocks for chemical industries. Recently, there has been a renaissance of awareness of plant terpenoids as a valuable biological resource for societies that will have to become less reliant on petrochemicals. Harnessing the powers of plant and microbial systems for production of economically valuable plant terpenoids requires interdisciplinary and often expensive research into their chemistry, biosynthesis and genomics, as well as metabolic and biochemical engineering. This paper provides an overview of the formation of hemi-, mono-, sesqui- and diterpenoids in plants, and highlights some well-established examples for these classes of terpenoids in the context of biomaterials and biofuels.     

Herbicides and their potential to disrupt plant–insect chemical communication

Ecological interactions between plants and insects are of paramount importance for the maintenance of biodiversity and ecosystem functioning. Herbicides have long been considered a threat to plant and insect populations, but global increases in intensive agriculture and availability of herbicide-resistant crops have intensified concerns about their full impact on biodiversity. Here, we argue that exposure to sublethal herbicide doses has the potential to alter plant–insect interactions as a result of disruptions in their chemical communication. This is because herbicides interfere with biosynthetic pathways and phytohormones involved in the production of several classes of plant volatiles that mediate plant–insect chemical communication. Sublethal herbicide doses can modify the morphological and life-history plant traits and affect interactions with insects. However, the potential changes in plant volatiles and their consequences for plant–insect chemical communication have not yet received as much attention. We discuss how target-site (disruptors of primary metabolism) and non-target-site (synthetic auxins) herbicides could alter the production of plant volatiles and disrupt plant–insect chemical communication. We suggest research avenues to fill in the current gap in our knowledge that might derive recommendations and applied solutions to minimize herbicides' impacts on plant–insect interactions and biodiversity.     

植物合成长链多不饱和脂肪酸研究进展

长链不饱和脂肪酸（LC-PUFAs）对人类健康具有重要作用,通过转基因植物生产LC-PUFAs具有低成本、可持续、污染少等诸多优势。本文简要介绍了LC-PUFAs的作用、来源及其植物生物合成途径,综述了转基因植物合成LC-PUFAs的研究进展,并对如何进一步提高LC-PUFAs产量进行了探讨。     

Antimony Trichloride as A Test Reagent for Steroids, Especially Diosgenin and Yamogenin, in Plant Tissues

A saturated solution of SbCl₃ in 60% HClO₄ was used to detect steroids in plant tissue, using (a) cut sections of fresh material (b) dried and powdered material and (c) dried aqueous ethanolic extracts of microquantities of tissues. The utility of this reagent as a microchemical test for diosgenin and yamogenin has been established by application to 55 plant specimens from 35 species in 12 families, including plant parts which hold steroidal sapogenin (spirostans) as well as those that do not. The presence or absence of spirostans in the plant parts was confirmed by infrared analysis after processing the material on a macro scale. Colours obtained with the reagent and pure sapogenins, some of their common derivatives and their glycosides are given for reference.     

Organelle Identification and Characterization in Plant Cells: Using a Combinational Approach of Confocal Immunofluorescence and Electron Microscope

The plant secretory and endocytic pathways consist of several functionally distinct membrane-bounded compartments. The ultra structures of the endoplasmic reticulum, the Golgi apparatus, and central vacuoles have been well characterized via traditional structural electron microscope (EM). However, the identification of plant prevacuolar compartments (PVCs) and early endosomes (EEs) had not been achieved until more recently because of the lack of specific markers for these organelles. Recent development of fluorescent reporters for PVCs and EEs expressing in transgenic tobacco BY-2 cells and Arabidopsis plants has allowed their dynamic characterization in living cells via confocal microscopy and drug treatment, which led to their subsequent morphological identification via structural and immunogold EM. Thus, in this review, we will use our studies on PVCs and EEs as examples to present an efficient approach for organelle identification in plant cells via primary characterization of fluorescent-marked organelles in living cells and their dynamic response to drug treatments, which then serves as the basis for subsequent immunogold and structural EM studies for organelle identification. Such strategy thus represents a powerful approach in future research for the identification of novel organelles and transport vesicles in plant cells.     

Analysis of Brassinosteroids in Plants

Brassinosteroids (BRs) are the polyhydroxylated plant hormones sharing a common resemblance with animal steroids. They are active even at very low concentrations and are implicated for their pleiotropic involvement in diverse physiological processes and defense strategies during stress in plants. These compounds are well apparent in the plant kingdom with higher amounts in juvenile tissues. A total of 62 steroidal compounds have been identified so far. Keeping their significance in mind, researchers not only have worked extensively on their isolation, but also they were synthesizing their synthetic isomers. Different analytical techniques like HPLC, GC-MS, LC-MS/MS, UPLC-MS/MS, and bioassay-based methods have been used for their isolation, detection, and characterization from composite plant materials. Therefore, this review provides comprehensive information to the readers intending to isolate and characterize BRs, using either laborious techniques or modern-day more efficient methods.     

GTP-Binding Regulatory Proteins in Higher Plant Cells

The exsitence of GTP-binding regulatory proteins (for short term, often refered as G-proteins) in higher plant cells is certain. G-proteins are classified into two groups based on their molecular structures, which are the heterotrimeric G-proteins (big G-proteins) that contain three different subunits and the small G-proteins that have only one subunit (monomeric G-proteins). All G-proteins are characterized by their properties to bind with and hydrolyze GTP, by which G-proteins function as transmembrane and intracellular signalling molecules. As a distinguished participant in signal transduction, G-proteins directly and/or indirectly regulate a number of physiological processes, such as regulation of phytochrome-related physiological processes and gene expression, involvement in blue-light response, K+-channel regulation, stomatal movement, hormone regulation, protein phosphrylation dephosphorylation, etc. Although G-proteins in plant cells have not been purified, the genes for a subunit of heterotrimeric G-proteins have been cloned. More evidences for the importance of G-proteins in plant signalling processes are rapidly accumulating.