A new triglucosylated naphthalene glycoside from Aloe vera L.

A new triglucosylated naphthalene derivative, named aloveroside A (1), together with two known anthraquinone dimers and two 6-phenyl-2-pyrone derivatives, was isolated from the Aloe vera ethanolic extracts. The structure of 1 was established as 1-(((4-(1-O-β-D-glucopyranosyl -(1→4)-β-D-xylopyranoside)-hydroxymethyl)-1-hydroxy-8-O-α-L-rhamnopyranoside)naphthalene-2-yl)-ethanone by means of spectroscopic evidences and chemical methods. All these compounds were tested for their BACE inhibitory activity but no significant activities were found.     

Evaluation of smoke from mosquito coils containing Malaysian plants against Aedes aegypti

Nineteen mosquito coil formulations, each containing a different plant, were prepared and investigated for their knock-down and 24-h mortality values against Aedes aegypti. Among them, only Azadirachta indica, Fernandao adenophylla, Eurycoma longifolia, Aloe vera and Cymbopogon nardus showed moderate knock-down (KD) values, though the mortality values were insignificant. When d-trans-allethrin (0.01–0.1%) was added, the coils showed dose-dependent KD₅₀, KD₉₀ and mortality values. At 0.1% d-trans-allethrin concentration, the coils showed KD values comparable with those of a reference commercial mosquito coil containing a same amount of pyrethroid, while C. nardus coil exhibited significantly shorter KD values. The mortality values observed with coils of C. nardus, A. vera and A. indica containing 0.1% d-trans-allethrin were significantly greater than that of the reference coil.     

Foliar pathogen and insect herbivore effects on two landslide tree species in Puerto Rico

To better understand pathogen/herbivore interactions and landslide regeneration, percent leaf area lost to disease and herbivory on two Puerto Rican trees over a 1-year period was sampled. Cecropia schreberiana saplings lost from 1 to 3% leaf area to pathogens and from 1 to 7% to herbivores. For Inga vera, both sapling and seedling losses to pathogens were minimal, but Inga herbivory losses reached 25% for saplings and 34% for seedlings. The most common fungi on Cecropia leaves were species in the genera Phoma and Phyllosticta, and on Inga leaves was Colletotrichum gloeosporioides. Percent survivorship after 1 year in the field varied among species and life-form (46% for Cecropia saplings, 15% for Inga saplings, 0% for Inga seedlings). There were no effects of pathogens or herbivores on survivorship or growth, but increased levels of herbivory did significantly correlate with total phenolics and condensed tannins in both Inga seedlings and saplings. For both seedlings and saplings of two trees on the neotropic island of Puerto Rico: (1) leaf herbivory was modest and leaf losses to pathogen disease were small; (2) these mechanisms did not affect survivorship or growth; (3) a neotropical tree (I. vera) displayed increased levels of secondary chemicals in its leaves, correlated with increased levels of insect herbivory.     

蓝花楹JaCBF1转录因子片段的序列分析及耐寒性功能验证

CBF类转录因子是调控植物冷害应答反应的关键因子.从蓝花楹中克隆到一个457 bp CBF类基因片段,序列分析表明其编码142氨基酸的片段,并与多个物种CBF1基因序列高度同源,且具有CBF家族的AP2核心结构域,因此将其命名为JaCBF1.原核表达的结果显示此基因片段编码16 kDa的蛋白,表达分析结果显示JaCBF1于低温条件下在蓝花楹根、茎、叶中有差异性转录.Southern杂交结果揭示JaCBF1在蓝花楹基因组中存在至少2个拷贝.通过脓杆菌介导方法将JaCBF1异源转录到拟南芥中,荧光共聚焦显微照相结果显示其编码的蛋白质定位于细胞核,冷处理实验发现转基因拟南芥植株的耐冷性得到了显著提高,表明此新片段具有CBF类植物耐冷因子的典型功能.     

美洲大蠊乙酸乙酯提取物的分离和抑菌活性分析

采用活性追踪法和柱层析法,以金黄色葡萄球菌、大肠杆菌等5种细菌为供试菌种,对美洲大蠊乙酸乙酯提取物进行分离和抑菌试验.研究发现:美洲大蠊乙酸乙酯提取物对供试的革兰氏阳性菌具有一定的抑制作用,其中,对枯草芽孢杆菌的抑菌活性最好;经硅胶柱层析初分离后,从乙酸乙酯提取物获得了9个具有抑菌活性的组分,其中,组分Fr7对5种供试菌均显示了较好的抑菌活性;组分Fr7及其相邻组分Fr8经硅胶和凝胶柱层析进一步分离纯化后,得到了7个具有抑菌活性的不饱和脂肪酸类化合物,均对藤黄微球菌表现出最好的抑菌活性.结果表明:美洲大蠊乙酸乙酯提取物的抑菌活性物质为不饱和脂肪酸类化合物,对供试的革兰氏阳性菌的抑菌活性较强.     

Wildfire promotes broadleaves and species mixture in boreal forest

Postfire tree species compositions are predicted to be the same prior to fire according to the direct regeneration hypothesis (DRH). We studied 94 upland boreal forest stands between 5 and 18 years after fire in Ontario, Canada. Postfire species-specific regeneration density was positively related to prefire stand basal area for Pinus banksiana, Populus spp., Betula papyrifera and Picea mariana, but not for Picea glauca and Abies balsamea. In addition, seedling density of Populus spp., B. papyrifera, P. mariana, P. glauca and A. balsamea were positively affected by build up index and, except Populus spp., their density increased with age of burn. To facilitate testing the DRH, we introduced a term called compositional difference (CD) that is the difference in a species relative percentage between the postfire and prefire stand. The testable null hypothesis is CD = 0 for a given species. CD was not different from 0 for P. banksiana, was 19.8% for Populus spp., 10.4% for B. papyrifera, −17.9% for P. mariana, −14.6% for P. glauca, and −14.9% for A. balsamea, indicating fire increases broadleaves at the expenses of mid- and late-successional coniferous species. Compositional increases of Populus spp. and B. papyrifera in postfire stands occurred mostly where these species were a minor component prior to fire. In conclusion, the DRH was supported by the specific positive relationships between postfire regeneration densities and prefire basal area for P. banksiana, Populus spp., B. papyrifera and P. mariana. However, if the DRH is used for predicting postfire composition, P. banksiana is the only species that had the same composition between postfire and prefire stands. Nevertheless, CD for P. banksiana was negatively related to its prefire composition. Similarly, CD for other species was negatively related to their prefire compositions with varying effects of build up index and age of burn. Our results suggest, if fire occurrences increase with global change, the boreal landscape will be more dominated by hardwoods and mixtures of conifers and hardwoods.     

猴头菌锰过氧化物酶1基因在构巢曲霉的异源转化与表达

为提高猴头菌菌株CB1锰过氧化物酶(MnP)基因的表达产量,采用PEG/CaCl2介导的原生质体转化方法,将携带有He-mnp1的重组质粒pLB01/He-mnp1转入到构巢曲霉尿嘧啶尿苷营养缺陷菌株TN02A7的原生质体中,获得了转化子菌株TN02A7-He-mnp1,并在乙醇脱氢酶启动子alcA(p)控制下实现了异源表达。将TN02A7-He-mnp1、TN02A7、构巢曲霉野生型菌株WJA01、猴头菌菌株CB1在相同的木质素环境下进行培养并检测MnP酶活性,结果表明:转化子菌株TN02A7-He-mnp1在0.05 g.L-1血红素的情况下、诱导96 h后酶活性最高为38.31 U.L-1,比不添加血红素的酶活力高8.64倍,但比猴头菌菌株CB1的酶活力低,而TN02A7与WJA01始终无MnP酶活性,说明基因He-mnp1已经成功地被转化到TN02A7-He-mnp1中,并在木质素环境下得到表达,血红素是重组MnP基因异源表达的限制性因素之一。本文为生产MnP和提高MnP产量提供了新的途径。     

Stand level estimation of root respiration for two subtropical plantations based on in situ measurement of specific root respiration

In this study, the stand level root respiration was estimated for two monoculture plantations: Acacia crassicarpa and Eucalyptus urophylla, based on in situ measurement of specific root respiration using simplified root chamber method. The respiration rates of fine roots (<5 mm) were significantly higher than those of coarse roots (>5 mm) for both A. crassicarpa and E. urophylla species. The root respiration of A. crassicarpa showed a clear seasonal pattern with a higher value in the wet season. For E. urophylla, the seasonal pattern was observed for fine roots but not for coarse roots. After determining the biomass of fine roots and coarse roots and their specific rates of respiration at different time points, root respiration at the stand level (R_a) was estimated using a direct up-scaling model. We found that the R_a accounted for 14% and 19% of total soil respiration (R_s) for A. crassicarpa and E. urophylla, respectively. The fine (R_Tf) and coarse (R_Tc) root respiration at the stand level accounted for about 47% and 53% of the R_a for A. crassicarpa, and accounted for 58% and 42% for E. urophylla. This suggests that coarse root respiration cannot be ignored when estimating the root respiration at the stand level. Our results showed that the Q₁₀ values were more accurate in representing the temperature dependence when the confounding effect of soil moisture was considered. This study introduces an alternative approach to estimate stand level root respiration, but its reliability is largely dependent on the accuracy of root biomass quantification.     

Facilitation by two exotic Acacia: Acacia auriculiformis and Acacia mangium as nurse plants in South China

Because of their high growth rate and tolerance to bare soil, two exotic Acacia species, Acacia auriculiformis and Acacia mangium, have been commonly planted in degraded areas of South China. With their large canopies and ability to fix nitrogen, the two Acacia species have also been considered to act as nurse plants for understory plants. The current study clarified the nursing effects of the Acacia species by comparing microclimate characteristics and physiological traits of native plant seedlings at three sites: under the canopies of the each Acacia species and on bare land (open site). Although the sites were not replicated, the results indicated that adult trees of both Acacia species can facilitate native species, but that A. mangium has greater facilitating effects due to greater temperature buffering, radiation reduction, and nutrient amelioration. In response to facilitation, three species (Castanopsis hystrix, Michelia macclurei, and Manglietia glauca) with different shade-tolerant traits growing under Acacia canopies expressed distinct adaptations. For the three species, the chlorophyll fluorescence curves of rETR and ΔF/Fm′ were higher under A. auriculiformis and on the open site than under A. mangium. The maximum quantum yield in PSII(Fv/Fm) in diurnal changes of the three species showed that all the Fv/Fm values were between 0.70 and 0.84 and that the Fv/Fm values were mostly higher under A. mangium than on the open site or under A. auriculiformis. Total chlorophyll content and both chlorophyll a and b contents in the three species were higher under the Acacia species than on the open site, while chlorophyll a/b ratio was higher on the open site. In contrast, the carotenoid content in C. hystrix and M. macclurei was lower under the two Acacia species than on the open site, while the opposite was true for M. glauca. The results demonstrate that the adaptation of the understory species to abiotic environmental factors is not restricted to a single mechanism but apparently involves a group of interrelated, adaptive suites. And also these adaptations were species-specific and especially related to their shade tolerance.     

一种新的白蜡虫寄生蜂体内Wolbachia的wsp基因分子检测及序列分析

采用Wolbachia的通用引物、A大组和B大组的特异性引物对一种新的白蜡虫寄生蜂--长尾啮小蜂(Aprostocetus sp.)体内Wolbachia的wsp基因进行分子检测,所获得的基因片段分别命名为wApr、wAprB和wAprB,长度分别为620、566和463bp;基因序列分析表明:wApA、wAprB与w...     

马尾松谷胱甘肽过氧化物酶PmGPX6基因cDNA克隆及转化拟南芥耐旱性初步研究

[目的]克隆马尾松谷胱甘肽过氧化物酶基因,并对其进行功能研究。[方法]采用RACE技术克隆基因c DNA序列,实时荧光定量PCR检测基因在马尾松干旱胁迫下的表达模式,花序浸泡法转化拟南芥,并对转基因与野生型拟南芥的生长表型和根系生长进行分析。利用荧光显微镜技术对转基因拟南芥不定根进行GFP荧光检测。[结果]克隆到1个871 bp的GPX基因全长c DNA序列,命名为Pm GPX6。Pm GPX6包括513 bp的完整开放阅读框,编码170个氨基酸残基。Pm GPX6蛋白与油松Pt GPX蛋白同源性达95%。Pm GPX6在马尾松根中高表达,茎、叶中表达量低。在干旱胁迫下,Pm GPX6在根、茎、叶中的表达量均在第15天达到最大,随后出现下降趋势。过表达Pm GPX6与野生型拟南芥植株在正常水分条件下表型与根长差异不大,但在干旱胁迫下,转基因植株根系更长。转基因拟南芥根在蓝色光激发下能发出强烈的绿色荧光,表明Pm GPX6基因能高效表达。[结论]推测Pm GPX6可能参与马尾松干旱胁迫应答。     

Anti-inflammatory, antiviral and quantitative study of quercetin-3-O-β-D-glucuronide in Polygonum perfoliatum L

Quercetin-3-O-β-D-glucuronide, isolated from Polygonum perfoliatum L., was evaluated by antiviral efficacy against influenza A virus and anti-inflammatory activity in vivo in mouse, and it was used for quality evaluation of P. perfoliatum L.. In vivo study, oral administration of quercetin-3-O-β-D-glucuronide significantly suppressed ear edema induced by dimethyl benzene and peritoneal permeability induced by acetic acid in mice, and quercetin-3-O-β-D-glucuronide also showed to possess inhibitory activity against influenza A virus (FLUAV). In the present study, additionally, a rapid, simple and sensitive method for quantitative analysis of quercetin-3-O-β-D-glucuronide in P. perfoliatum L. was developed using high performance liquid chromatography (HPLC) coupled with photodiode array detection. The separation was carried out on a Lichrosher-C18 column (250 mm × 4.6 mm, 5 μm) together with a C18 guard column at isocratic elution systems of methanol (A) and 0.05% aqueous phosphoric acid (B) (43:57, v/v) with detection wavelength at 258 nm and column temperature at 30 °C. The method was validated for linearity, repeatability, limit of quantification (LOQ), precision and robustness. The contents of quercetin-3-O-β-D-glucuronide in 28 samples from different regions of China were between 0.06% and 2.09%. The developed analytical method was applied to investigate P. perfoliatum L. and for quality control of the herb.     

诱导和非诱导条件下喙尾琵甲幼虫抗菌肽分离及抑菌活性比较

对混合菌液诱导和非诱导处理的喙尾琵甲幼虫抗菌肽进行了分离纯化及抑菌活性比较。结果显示:诱导组和非诱导组粗提物无抑菌活性,但是经凝胶色谱分离后,从非诱导组获得组分DZP1,对金黄色葡萄球菌、枯草芽孢杆菌表现出抑制作用;从诱导组获得组分YDP1,对金黄色葡萄球菌、枯草芽孢杆菌、绿脓杆菌具有活性,且YDP1活性明显强于DZP1;Tricine-SDS-PAGE检测表明DZP1和YDP1组成、种类基本一致,主要由20 kD以下分子量的小肽组成。研究结果表明:喙尾琵甲幼虫在诱导和非诱导条件下均可分离到具有抑菌活性的抗菌肽,菌液诱导可增强抗菌肽的活性和抑菌谱。     

油茶根际高效溶磷细菌的筛选、鉴定及其安全性测试

本研究利用溶磷圈法和钼锑抗比色法,从油茶根际分离出20株高效溶无机磷细菌,并对其溶磷能力进行定性和定量测试,结果发现,D/d与溶磷细菌的有效磷含量之间没有显著的相关性,而培养液p H与有效磷含量之间存在极显著的负相关性关系(P<0.01)。并采用形态特征、生理生化、Biolog系统和16Sr DNA序列分析对一株溶磷效果最好的菌株NC285进行菌株鉴定,确定其为Bacillus aryabhattai。通过苜蓿植物模型和cbl A毒力基因测定对该菌株进行安全性检测,结果发现,该菌株未检测到cbl A基因,对洋葱和苜蓿安全无致病性。本研究对溶磷细菌的安全应用及提高油茶土壤磷素利用效率具有重要意义。     

日本落叶松杂种及亲本 4CL基因的克隆和SNP多态性分析

以日本落叶松(Larix kaempferi)不同杂交组合为材料,依据转录组测序信息,成功获得了11种日本落叶松材料的4 CL基因的编码区序列,该序列长1 537 bp,包含完整ORF片段1 368 bp,编码455个氨基酸。qRT-PCR结果分析表明,除日本落叶松Larix16×Larix61组合外,Larix82×Larix13、Larix40×Larix10和Larix82×Larix61子代的表达均高于双亲,推测4 CL基因差异表达与落叶松杂种的木质素生物合成有关。进一步采用SNP标记方法和DNAMAN软件对不同日本落叶松杂种和亲本组合的单核苷酸多态性进行分析。共检测到66个SNP多态性位点,表明日本落叶松4CL 具有丰富的遗传多样性。66个SNP变异中,属于三突变1个;转换类型45个,占总变异的68.18%;20个属于颠换类型,占总变异的30.30%,转换:颠换=9:4。在转换类型中,A/G和C/T转换分别占28.79%和39.39%;颠换类型中A/C、A/T、G/C、G/T分别占4.55%、9.09%、9.09%和7.58%。采用NJ 聚类法对克隆片段的氨基酸序列进行了遗传多样性分析。     

Effect of species and spacing of fast-growing nurse trees on growth of an indigenous tree, Hopea odorata Roxb., in northeast Thailand

We tested the effects of species and spacing of nurse trees on the growth of Hopea odorata, a dipterocarp tree indigenous to Southeast Asia, in a two-storied forest management system in northeast Thailand. Eucalyptus camaldulensis, Acacia auriculiformis, and Senna siamea were planted as nurse trees in 1987 at spacings of 4 m × 8 m, 2 m × 8 m, 4 m × 4 m, and 2 m × 4 m in the Sakaerat Silvicultural Research Station of the Royal Forest Department, Thailand. Seedlings of H. odorata were planted in the nurse tree stands at a uniform spacing of 4 m × 4 m and in control plots (no nurse trees) in 1990. Stem numbers of some nurse trees were thinned by half in 1994. The stem diameter and height of all trees were measured annually until 1995 and again in 2007. The mean annual increment (MAI) in volume was estimated as 8.2–10.1 m³ ha⁻¹ year⁻¹ for E. camaldulensis and 0.9–1.2 m³ ha⁻¹ year⁻¹ for S. siamea, smaller than reported elsewhere. This suggests that the site properties were not suitable for them. The MAI of A. auriculiformis was 7.9–9.8 m³ ha⁻¹ year⁻¹, within the reported range. Survival rates of H. odorata in the S. siamea stands and the control plots decreased rapidly during the first 2 years but then stayed constant from 1992. In contrast, survival rates of H. odorata in the E. camaldulensis and A. auriculiformis stands were initially high (>70%), but then decreased after 1995. Stem diameter, tree height, and stand basal area of H. odorata were large in both the S. siamea stands and the control plots from then. The growth of H. odorata was largest in the 2 m × 8 m S. siamea stands. In contrast, it was restricted in the E. camaldulensis and A. auriculiformis stands owing to strong shading by their canopies. Thinning by 50% tended to facilitate the growth of H. odorata temporarily in the E. camaldulensis and A. auriculiformis stands. The stand basal areas of nurse trees and of H. odorata showed a trade-off. These results suggest that the growth of H. odorata was maximized in the S. siamea stands. We assume, however, that the growth of H. odorata could be improved even in the E. camaldulensis and A. auriculiformis stands by frequent or heavy thinning.     

Anti-inflammatory and analgesic properties of cis-mulberroside A from Ramulus mori

This study examined the analgesic and anti-inflammatory actions of cis-mulberroside A isolated from Ramulus mori in several models of inflammatory pain in mice. Cis-mulberroside A (25 and 50 mg/kg) given by p.o. route 30 min before challenge produced a dose-dependent inhibition of the acetic acid-induced pain and Evans blue leakage in mice. In addition, this compound exhibited significant systemic anti-inflammatory activity in carrageenan-induced mouse paw edema in a concentration-related manner (33.1–68.5% inhibition), and similar results were achieved in formalin test. Suppressive effects of cis-mulberroside A on the production of NO and expression of inducible nitric oxide synthase (iNOS) in lipopolysaccharide (LPS)-stimulated macrophages were also assessed. Collectively, cis-mulberroside A showed high analgesic and anti-inflammatory activities. The above results will be the supporting evidence for the potential anti-rheumatoid activity of R.mori in Chinese traditional medicine.     

中国广义金合欢属植物亲缘关系的分子分析

通过ITS-rpl16序列和mat K序列的分子分析,对中国现有金合欢属的各亚属间的亲缘关系进行了研究,结果表明:我国现有广义金合欢属的14个种大致被聚为相思亚属、皮刺亚属和金合欢亚属3大类,原产中国的3种皮刺亚属的种聚成1支,表明印度金合欢和羽叶金合欢关系更近,二者再与儿茶形成姐妹类群。基于选自美洲、非洲、澳大利亚和中国乡土种(印度金合欢、羽叶金合欢和儿茶)共40个金合欢属种和1个外类群的mat K序列建立的系统发育树表明:皮刺亚属和相思亚属的亲缘性关系比与金合欢亚属的亲缘关系更近,相思亚属和金合欢亚属均是单系类群,而皮刺亚属属于并系类群;中国的几个乡土种都与非洲一些种的亲缘关系较近,聚为1支。     

马尾松钙调素基因的克隆及响应松材线虫侵染的表达特征

松材线虫病是由松材线虫(Bursaphelenchus xylophilus)侵染引起的严重病害,引起重大的经济和生态损失。钙调素(CaM)是真核生物中Ca2+主要传导蛋白,本研究采用RT-PCR方法,首次从马尾松中克隆获得CaM,命名为pmCaM,并检测了其响应松材线虫侵染的表达特征。序列分析表明:pmCaM完整的开放阅读框核苷酸序列为450bp,编码149个氨基酸的蛋白质;该蛋白含有4个EF-hand结构域,具有钙调素的典型特征,与其它植物的CaM蛋白均有较高同源性。实时荧光定量PCR分析显示:接种松材线虫后30 180 min时间段,马尾松苗根、茎、叶器官中的pmCaM均下调表达,但不同器官间显著下调表达的时间点存在差异;同时,不同器官pmCaM表达量变化均存在特异的随时间发展的波动特征,其中发现,根茎pmCaM在松材线虫接种45 min时均处于表达量高峰。本研究结果显示pmCaM表达响应了松材线虫侵染,揭示pmCaM可能参与了调控松材线虫-马尾松互作早期的钙信号响应。     

白蜡虫阔柄跳小蜂体内Wolbachia的wsp基因分子检测及序列分析

采用Wolbachia的通用引物对白蜡虫优势寄生蜂之一,白蜡虫阔柄跳小蜂(Metaphycus ericeriXu et Jiang)体内Wolbachia的wsp基因进行PCR扩增,以此为模板结合Wolbachia的A大组和B大组的特异性引物进行巢式PCR扩增,结果表明:白蜡虫阔柄跳小蜂被A大组和B大组Wolbachia复合感染,将两种寄生蜂感染的A大组和B大组Wolbachia基因片段以及采用通用引物获得的基因片段分别命名为wMeeriA、wMeeriB和wMeeri,对应的片段长度分别为554、439、599 bp。系统发育分析表明:白蜡虫阔柄跳小蜂感染的Wolbachia分属于A大组以及B大组的Con亚组。所获得的序列已经递交到NCBI,登录号分别为:HQ161162、HQ161163和HQ161164。