北柴胡不定根系生物转化合成皂苷研究

通过在北柴胡不定根系培养体系中添加目的产物柴胡皂苷的前体物质和生物合成促进物质以及进行高糖渗透胁迫试验,探讨了利用不定根系生产柴胡皂苷的条件和方法。结果表明,在1/2 MS培养基中添加硫酸镁、硝酸钾、丙酮酸钠以及高糖渗透胁迫均有利于柴胡皂苷的合成。1/2 MS培养基+硫酸镁0.37 g/L+硝酸钾5.7 g/L+丙酮酸钠2.0 mmol/L+蔗糖50 g/L是最适合柴胡皂苷转化合成的培养基,此条件下使柴胡皂苷的含量提高了9.74倍。     

紫茎泽兰9-羰基-10,11-去氢泽兰酮分布积累动态

9-羰基-10,11-去氢泽兰酮为紫茎泽兰（Eupatorium adenophorum）的主要致肝脏毒性成分及杀虫的生物活性成分。从紫茎泽兰叶片中分离提纯得到9-羰基-10,11-去氢泽兰酮（Euptox A）标准品,建立了高效液相色谱法测定紫茎泽兰中Euptox A含量的分析方法。采用C18反相色谱柱,柱温30°C,以甲醇-水（60：40,v/v）为流动相、流速为0.8 mL.min–1、检测波长为255 nm进行测定。Euptox A在紫茎泽兰中的添加回收率为97.3%–103.7%,检测限为0.4μg.g–1。利用建立的方法测定Euptox A在紫茎泽兰体内分布与积累的动态变化规律。结果表明,Euptox A主要分布在紫茎泽兰的叶片中,且在营养生长期积累量高,生殖生长期积累量低。该方法快速、简捷,可用于紫茎泽兰原料及其产品中Euptox A成分的测定。     

3种药赏两用植物对滨海盐碱土改良效应的比较

为比较种植药赏两用植物对滨海盐碱土的改良效应,采用实生栽培方法种植了薄荷(Mentha haplocalyxBriq.)、地榆(Sanguisorba officinalis L.)和枸杞(Lycium chinense Mill.)1年生植株,对不同土层的pH值以及可溶性盐和主要离子含量的变化进行了比较分析。结果表明:种植3种植物后,0～10、10～20和20～30 cm土层的pH值以及可溶性盐、K+、Na+、Ca2+、Mg2+、Cl-和SO42-含量均有不同程度的变化,且以0～10 cm土层的变化相对明显,并且各土层的离子组成也有所改变。种植3种植物后,0～10和10～20 cm土层的pH值以及0～10 cm土层的可溶性盐含量均低于对照,其中,地榆种植土壤pH值及枸杞种植土壤可溶性盐含量的降低效应最明显。种植3种植物后,各土层的Ca2+含量及10～20和20～30 cm土层的K+和Mg2+含量均极显著高于对照,各土层的Na+含量及0～10 cm土层的Cl-含量、10～20和20～30 cm土层的SO42-含量均极显著低于对照;不同土层的K+/Na+值均高于对照、(K++Na+)/(Ca2++Mg2+)值均低于对照、主要阳离子(Ca2+、K+和Mg2+)的交换量总和均明显增加。总体上,地榆和枸杞对土壤中K+及Ca2+和Mg2+含量、K+/Na+值、主要阳离子(Ca2+、K+和Mg2+)交换量总和的提高效应以及对Na+含量、(K++Na+)/(Ca2++Mg2+)值的降低作用均较强,而薄荷的作用均较弱。研究结果显示:供试的3种药赏两用植物对盐碱地均具有明显的改良作用,其中枸杞和地榆的改良效果较好。     

A New Alkaloid from the Aerial Parts of Bupleurum chinense DC.

A new isoalloxazine alkaloid, named bupleurine A ( 1 ), along with five known compounds ( 2 – 6 ), were isolated from the aerial parts of Bupleurum chinense DC. The structure elucidation of the new alkaloid ( 1 ) was employed by combining NMR and HR‐MS data with comparison of reference in the literature. Five known compounds ( 2 – 6 ) were isolated from Bupleurum genus for the first time. Additionally, their antiproliferative activities on HeLa cells were evaluated by MTT assay and IC₅₀ of compounds 1 and 4 – 6 were below 10 μm after treatment for 24 h.     

紫茎泽兰对四环素的吸收特性

[目的] 探究四环素在水和紫茎泽兰间的传递以及在紫茎泽兰体内的累积特征。[方法] 利用高效液相色谱检测紫茎泽兰幼苗在水培过程中对四环素的吸收及其在根茎叶中的积累。[结果] 在10~20 mg·L^-1四环素的处理浓度范围内,紫茎泽兰根、茎、叶均能吸收并积累四环素,且吸收累积量均随处理浓度和处理时间的增加而升高。当紫茎泽兰在20 mg·L^-1四环素的水培液处理20 d时,茎中的四环素累积量最高,为（59.34±3.86）mg·kg^-1;根中的次之,为（52.52±5.89）mg·kg^-1;而叶中的最低,为（23.19±4.17）mg·kg^-1。此外,紫茎泽兰茎的四环素富集系数最大,根的次之,叶的最小。[结论] 紫茎泽兰能够较好地从水培液中吸收并累积四环素,具有吸收净化四环素污染水源的潜力。     

干扰强度对群落中紫茎泽兰种子萌发、幼苗定居和生长的影响

干扰与外来植物入侵密切相关,种子萌发和幼苗定居是植物生活史中最脆弱、也是外来植物入侵最关键的阶段.为研究干扰在恶性外来入侵植物紫茎泽兰成功入侵过程中的作用,采用人工牧草群落代替自然群落,人为干扰(去除不同面积的牧草)模拟自然干扰的方式,研究了紫茎泽兰入侵初期种子萌发、幼苗定居和生长对不同干扰强度的响应与适应.结果表明:...     

大孔树脂纯化赶黄草黄酮工艺及体外抗氧化活性

本研究以赶黄草地上部分为材料,研究大孔树脂纯化赶黄草黄酮的工艺,并评价体外抗氧化活性。根据大孔树脂对赶黄草黄酮的吸附和解吸性能,从7种不同类型的大孔树脂中筛选出适宜的树脂,进一步优化其纯化工艺,并比较纯化前后黄酮的体外抗氧化活性。试验结果表明,DM130大孔树脂对赶黄草黄酮有较好的吸附和解吸效果,其最佳纯化工艺参数:上样液黄酮浓度为1.0 mg/mL、pH为5、上样速度为1.0 mL/min、上样量为110 mL、洗脱液为70%乙醇、洗脱速度为1.0 mL/min和洗脱体积为40 mL。该工艺条件下,黄酮的纯度由20.04%提高至43.93%,提高了23.89%,表明DM130树脂对赶黄草黄酮的纯化效果较好。另外,纯化后赶黄草黄酮的DPPH自由基清除能力和还原力均显著提高。     

Phospholipase signaling is modified differentially by phytoregulators in Capsicum chinense J. cells

Plant defense mechanisms respond to diverse environmental factors and play key roles in signaling pathways. The phospholipidic signaling pathway forms part of the plant response to several phytoregulators, such as salicylic acid (SA) and methyl jasmonate (MJ), which have been widely used to stimulate secondary metabolite production in cell cultures.¹ Furthermore, it has been reported that the levels of such phytoregulators as SA and MJ can increase in response to stressful conditions.^2,3 The phospholipidic signal transduction system involves the generation of second messengers by the hydrolysis of phospholipids. In this study, we examined how phospholipidic signaling can be modulated depending on the growth stage of the culture, and we focused on two key lipases having relevant roles in the signaling cascades in plants. An evaluation was made of the effects of SA and MJ on the phospholipase activities in Capsicum chinense Jacq. suspension cells at different phases of the culture cycle. The treatment with SA differentially modified the phospholipase C (PLC) (EC: 3.1.4.3) and phospholipase D (PLD) (EC: 3.1.4.4) activities in a dose-dependent manner that also depended on the day of the culture cycle. In contrast, the treatment with MJ resulted in a biphasic behavior of the PLC and PLD activities. We conclude that the enzymatic activities in the phospholipidic signaling pathways are modified differentially depending on the day of the culture’s growth cycle; accordingly, the response capacity to such environmental factors as phytoregulators is variable at different stages of growth and the physiology of the cells.     

Inhibitory effects of leachate from Eupatorium adenophorum on germination and growth of Amaranthus retroflexus and Chenopodium glaucum

Amaranthus retroflexus L. and Chenopodium glaucum L. are two widely distributed destructive weeds. Their strong adaptability and massive seed production make them the hardest weeds to deal with. This present study intended to investigate the effect of leachate from Eupatorium adenophorum on the growth of these weeds and explore the potential to develop an environmental friendly strategy to use the leachate to control the weeds. Seeds of A. retroflexus L. and C. glaucum L. were soaked in solutions containing 0%, 0.6%, 1.25%, 2.5%, and 5% leachate from E. adenophorum leaves. A. retroflexus and C. glaucum seedlings grown in pots were sprayed with leachate solutions in the same concentration range. The effects of these leachate solutions on membrane permeability and germination of seeds, and growth and physiological characteristics of the seedlings were investigated. The highest concentration of leachate (5%) caused significant damage to the cell membrane of seeds of both weed species, whereas lower concentrations (0.6%) promoted repair of the membrane system, as reflected by higher and lower than control in relative conductivity (RC), respectively. Different concentrations of leachate showed distinct allelopathic inhibitory effects on the two weed species; lower concentrations showed weak inhibitory or even positive effects, whereas higher concentrations showed stronger inhibitory effects. Higher concentrations of leachate (2.5% and 5%) delayed germination and significantly decreased the emergence rate of the seeds, survival rate, and dry matter accumulation of the seedlings. When treated by 5% leachate, the emergence date of A. retroflexus was delayed by 3.6 d, emergence rate of the seeds and survival rate was 69.1% and 70.6% of the control, respectively, seedling dry matter was 48.6% less than the control; In the case of C. glaucum, the emergence date was delayed by 2.7 d, emergence rate of the seeds and survival rate was 45.1% and 58.6% of the control, respectively, seedling dry matter was 44.7% less than the control. There were significant interactions among the different concentrations of leachate and the length of treatment period with respect to activities of antioxidant enzymes, malondialdehyde (MDA) contents, and chlorophyll contents. Seedlings treated with 0.6%, 1.25%, or 2.5% leachate solution for 24–72 h showed increased superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activities. When seedlings were treated with leachate solutions for 96 h, antioxidant enzyme activities and chlorophyll content decreased in A. retroflexus, but only CAT activity decreased in C. glaucum. When seedlings of the two weed species were treated with 5% leachate solution, CAT activity and chlorophyll content decreased and MDA content gradually increased with longer treatment times (from 24 to 96 h). The two weed species showed different allelopathic responses to E. adenophorum; A. retroflexus was more sensitive than C. glaucum. Based on the investigation, it could be speculated that the delayed germination and low germination rate of the weeds after treatment by leachate could be due to the fact that leachate damaged the membrane system of the seeds. By delaying germination, lowering the germination rate of the weeds and inhibiting seedling growth, leachate from E. adenophorum could provide an effective way of controlling the weeds.     

Proteomic analysis of pathogenesis-related proteins (PRs) induced by compatible and incompatible interactions of pepper mild mottle virus (PMMoV) in Capsicum chinense L3 plants

Resistance conferred by the L³ gene is active against most ofthe tobamoviruses, including the Spanish strain (PMMoV-S), aP_1,2 pathotype, but not against certain strains of pepper mildmottle virus (PMMoV), termed P_1,2,3 pathotype, such as the Italianstrain (PMMoV-I). Both viruses are nearly identical at theirnucleotide sequence level (98%) and were used to challenge Capsicumchinense PI159236 plants harbouring the L³ gene in order tocarry out a comparative proteomic analysis of PR proteins inducedin this host in response to infection by either PMMoV-S or PMMoV-I.PMMoV-S induces a hypersensitive reaction (HR) in C. chinensePI159236 plant leaves with the formation of necrotic local lesionsand restriction of the virus at the primary infection sites.In this paper, C. chinense PR protein isoforms belonging tothe PR-1, β-1,3-glucanases (PR-2), chitinases (PR-3), osmotin-likeprotein (PR-5), peroxidases (PR-9), germin-like protein (PR-16),and PRp27 (PR-17) have been identified. Three of these PR proteinisoforms were specifically induced during PMMoV-S-activationof C. chinense L³ gene-mediated resistance: an acidic β-1,3-glucanaseisoform (PR-2) (M_r 44.6; pI 5.1), an osmotin-like protein (PR-5)(M_r 26.8; pI 7.5), and a basic PR-1 protein isoform (M_r 18;pI 9.4–10.0). In addition, evidence is presented for adifferential accumulation of C. chinense PR proteins and mRNAsin the compatible (PMMoV-I)–C. chinense and incompatible(PMMoV-S)–C. chinense interactions for proteins belongingto all PR proteins detected. Except for an acidic chitinase(PR-3) (M_r 30.2; pI 5.0), an earlier and higher accumulationof PR proteins and mRNAs was detected in plants associated withHR induction. Furthermore, the accumulation rates of PR proteinsand mRNA did not correlate with maximal accumulation levelsof viral RNA, thus indicating that PR protein expression mayreflect the physiological status of the plant. Key words: Capsicum chinense, compatible interaction, incompatible interaction, HR-induction, PMMoV, PR proteins Received 5 December 2007; Revised 21 January 2008 Accepted 22 January 2008