Selection of aquatic plants for phytoremediation of heavy metal in electroplate wastewater

The remediation of heavy metal-contaminated sites using plants is a promising alternative to current methodologies. In this study, small-scale wetlands were constructed to search for new plant species that are suitable and hold potential for phytoremediation of heavy metal-contaminated wastewater originating from an electroplating plant. Ten macrophyte species [Phragmites australis (Cav.) Trin., Typha orientalis Presl, Lythrum salicaria Linn., Arundo donax Linn. var. versicolor Stokes, Typha minima Funk, Juncus effusus L., Pontederia cordata L., Cyperus alternifolius Linn. subsp. flabelliformis (Rottb.) Kükenth., Acorus calamus Linn., and Iris pseudacorus Linn.] were investigated and compared for their shapes, biomass, roots, and ability to accumulate heavy metals. Acorus calamus Linn., T. orientalis Presl, P. australis (Cav.) Trin., T. minima Funk, and L. salicaria Linn. exhibited the highest levels of metal tolerance, whereas P. cordata L., I. pseudacorus Linn., and C. alternifolius Linn. subsp. flabelliformis (Rottb.) Kükenth. had the lowest. Some plants accumulated higher concentrations of metals in the tissues compared with other species such as T. minima Funk, P. australis (Cav.) Trin., L. salicaria Linn., A. donax Linn. var. versicolor Stokes, P. cordata L., and A. calamus Linn., whereas T. orientalis Presl and C. alternifolius Linn. subsp. flabelliformis (Rottb.) Kükenth. had poor capacity to accumulate heavy metals. The results showed that, of the 10 species, P. australis (Cav.) Trin., A. calamus Linn., T. minima Funk, and L. salicaria Linn. are the most suitable and promising plant materials for phytoremediation of heavy metal-contaminated wastewater.     

Differential contributions of plant Dicer‐like proteins to antiviral defences against potato virus X in leaves and roots

Members of the plant Dicer‐like (DCL) protein family are the critical components of the RNA‐silencing pathway that mediates innate antiviral defence. The distinct antiviral role of each individual DCL protein has been established with mostly based on observations of aerial parts of plants. Thus, although the roots are closely associated with the life cycle of many plant viruses, little is known about the antiviral activities of DCL proteins in roots. We observed that antiviral silencing strongly inhibits potato virus X (PVX) replication in roots of some susceptible Solanaceae species. Silencing of the DCL4 homolog in Nicotiana benthamiana partially elevated PVX replication levels in roots. In Arabidopsis thaliana, which was originally considered a non‐host plant of PVX, high levels of PVX accumulation in inoculated leaves were achieved by inactivation of DCL4, while in the upper leaves and roots, it required the additional inactivation of DCL2. In transgenic A. thaliana carrying the PVX amplicon with a green fluorescent protein (GFP) gene insertion in the chromosome (AMP243 line), absence of DCL4 enabled high levels of PVX‐GFP accumulation in various aerial organs but not in the roots, suggesting that DCL4 is critical for intracellular antiviral silencing in shoots but not in roots, where it can be functionally compensated by other DCL proteins. Together, the high level of functional redundancies among DCL proteins may contribute to the potent antiviral activities against PVX replication in roots.     

西藏被子植物分布新记录

首次报道了西藏被子植物8个新记录种：虎耳草科(Saxifragaceae)虎耳草属(Saxifraga Linn.)的阿墩子虎耳草(Saxifraga atuntsiensis W. W. Smith)、橙黄虎耳草(Saxifraga aurantiaca Franchet),罂粟科(Papaveraceae)紫堇属(Corydalis DC.)的雅曲距紫堇(Corydalis dolichocentra Z. Y. Su & Lidén),龙胆科(Gentianaceae)龙胆属(Gentiana Linn.)的圆萼龙胆(Gentiana suborbisepala C. Marquand),报春花科(Primulaceae)点地梅属(Androsace Linn.)的小点地梅［Androsace gmelinii (Linn.) Roemer & Schultes］,忍冬科(Caprifoliaceae)忍冬属(Lonicera Linn.)的垫状忍冬(Lonicera oreodoxa H. Smith ex Rehder J.),毛茛科(Ranunculaceae)毛茛属(Ranunculus Linn.)的川青毛茛(Ranunculus chuanchingensis L. Liou),玄参科(Scrophulariaceae)马先蒿属(Pedicularis Linn.)鹬形马先蒿(Pedicularis scolopax Maximowicz)。并提供其形态描述和照片,凭证标本保存于西藏高原生态研究所标本室(XZE)。     

Pressurized liquids as an alternative green process to extract antiviral agents from the edible seaweed <Emphasis Type="Italic">Himanthalia elongata</Emphasis>

Pressurized liquid extraction (PLE), an environmentally friendly technique, was used to obtain antiviral compounds from the edible seaweed Himanthalia elongata. The antiviral properties of PLE extracts (hexane, ethanol, and water) were evaluated against herpes simplex virus type 1 (HSV-1) at different stages during viral infection. Pre-treatment of Vero cells with 75 μg mL⁻¹ of ethanol extract inhibited virus infection by approximately 90%, whereas the same concentration of water and hexane extracts reduced the virus infectivity to 78% and 70%, respectively. Moreover, ethanol extract was also more effective against HSV-1 intracellular replication than water and hexane extracts. The antiviral activity of water PLE extract was found to correlate with polysaccharides, since the polysaccharide-rich fraction isolated from this extract showed higher antiviral activity than the original water extract. A GC–MS characterization of the hexane and ethanol extracts showed that the antiviral activity of the hexane extract seemed to be related with the presence of fucosterol; meanwhile, in the case of the ethanol extract, other compounds, besides fucosterol, could be involved in this activity. Results demonstrated that PLE was an appropriate technique to obtain antiviral agents from H. elongata. These antiviral compounds were in addition to polysaccharides, which are the antiviral agents usually proposed when studying seaweeds.     

Alpha-momorcharin enhances Nicotiana benthamiana resistance to tobacco mosaic virus infection through modulation of reactive oxygen species

Alpha-momorcharin (α-MMC), a member of the plant ribosomal inactivating proteins (RIPs) family, has been proven to exhibit important biological properties in animals, including antiviral, antimicrobial, and antitumour activities. However, the mechanism by which α-MMC increases plant resistance to viral infections remains unclear. To study the effect of α-MMC on plant viral defence and how α-MMC increases plant resistance to viruses, recombinant DNA and transgenic technologies were employed to investigate the role of α-MMC in Nicotiana benthamiana resistance to tobacco mosaic virus (TMV) infection. Treatment with α-MMC produced through DNA recombinant technology or overexpression of α-MMC mediated by transgenic technology alleviated TMV-induced oxidative damage and reduced the accumulation of reactive oxygen species (ROS) during TMV-green fluorescent protein infection of N. benthamiana. There was a significant decrease in TMV replication in the upper leaves following local α-MMC treatment and in α-MMC-overexpressing plants relative to control plants. These results suggest that application or overexpression of α-MMC in N. benthamiana increases resistance to TMV infection. Finally, our results showed that overexpression of α-MMC up-regulated the expression of ROS scavenging-related genes. α-MMC confers resistance to TMV infection by means of modulating ROS homeostasis through controlling the expression of antioxidant enzyme-encoding genes. Overall, our study revealed a new crosstalk mechanism between α-MMC and ROS during resistance to viral infection and provides a framework to understand the molecular mechanisms of α-MMC in plant defence against viral pathogens.     

Antiviral activity of Bignoniaceae species occurring in the State of Minas Gerais (Brazil): part 1

Aims: To evaluate the antiviral activity of Bignoniaceae species occurring in the state of Minas Gerais, Brazil. Methods and Results: Ethanol extracts of different anatomical parts of bignoniaceous plant species have been evaluated in vitro against human herpesvirus type 1 (HSV‐1), vaccinia virus (VACV) and murine encephalomyocarditis virus (EMCV) by the 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay. A total of 34 extracts from 18 plant species selected according to ethnopharmacological and taxonomic criteria were screened. Fifteen of the 34 extracts (44·1%) have disclosed antiviral activity against one or more of the viruses assayed with EC₅₀ values in the range of 23·2 ± 2·5–422·7 ± 10·9 μg ml^?1. Conclusions: Twelve of the 34 extracts (35·3%) might be considered promising sources of antiviral natural products, as they have shown EC₅₀ ≤ 100 μg ml^?1. The present screening discloses the high potential of the Bignoniaceae family as source of antiviral agents. Significance and Impact of the Study: Active extracts were identified and deserve bioguided studies for the isolation of antiviral compounds and studies on mechanism of action.     

In Vitro Anti-hepatitis B Virus Activity of 2',3'-Dideoxyguanosine

2',3'-dideoxyguanosine(DoG) has been demonstrated to inhibit duck hepatitis B virus(DHBV) replication in vivo in a duck model of HBV infection. In the current study, the in vitro antiviral effects of DoG on human and animal hepadnaviruses were investigated. Our results showed that DoG effectively inhibited HBV, DHBV, and woodchuck hepatitis virus(WHV)replication in hepatocyte-derived cells in a dose-dependent manner, with 50% effective concentrations(EC50) of 0.3 ± 0.05, 6.82 ± 0.25, and 23.0 ± 1.5 lmol/L, respectively. Similar to other hepadnaviral DNA polymerase inhibitors,DoG did not alter the levels of intracellular viral RNA but induced the accumulation of a less-than-full-length viral RNA species, which was recently demonstrated to be generated by RNase H cleavage of pgRNA. Furthermore, using a transient transfection assay, DoG showed similar antiviral activity against HBV wild-type, 3TC-resistant rtA181 V, and adefovirresistant rtN236T mutants. Our results suggest that DoG has potential as a nucleoside analogue drug with anti-HBV activity.     

西藏维管植物新记录

本研究首次发现西藏新记录属云实属(Caesalpinia Linn.)植物——见血飞(Caesalpinia cucullata Roxb.),另外报道了11个新记录种和2个变种:瓶尔小草科(Ophioglossaceae)薄叶阴地蕨(Botrychium daucifolium Wall.),凤尾蕨科(Pteridaceae)华中凤尾蕨(Pteris kiuschiuensis var.centrochinensis ChingS.H.Wu),毛茛科(Ranunculaceae)尾叶铁线莲(Clematis urophylla Franch.),椴树科(Tiliaceae)刺蒴麻(Triumfetta rhomboidea Jacq.),锦葵科(Malvaceae)拔毒散(Sida szechuensis Matsuda),中华地桃花[Urena lobata var.chinensis(Osbeck)S.Y.Hu],柳叶菜科(Onagraceae)草龙[Ludwigia hyssopifolia(G.Don)Exell]、卵叶丁香蓼(Ludwigia ovalis Miq.),唇形科(Lamiaceae)小鱼仙草[Mosla dianthera(Buch.-Ham.)Maxim.],玄参科(Scrophulariaceae)石龙尾[Limnophila sessiliflora(Vahl)Bl.],爵床科(Acanthaceae)白接骨[Asystasia neesiana(Wall.)Nees],桔梗科(Campanulaceae)卵叶半边莲(Lobelia zeylanica Linn.),天南星科(Araceae)百足藤[Pothos repens(Loureiro)Druce]。研究结果进一步丰富了西藏的植物区系,并为研究与相邻地区植物区系的联系增加了新内容。     

Studies on the enzymatic activities related to varied pattern of diets in the air-breathing cat fish,clarias batrachus (Linn.)

1. Specific activity of amylase, cellulase, protease and lipase in the intestines of the air-breathing catfish, Clarias batrachus (Linn.) has been studied.
2. Excepting amylase and protease, the activity of lipase and cellulase showed practically no changes with change in the nutritional status of the diets.
3. pH optima of all enzymes were between 6.9 and 7.6
4. There is reason to believe from cellulase and high amylase activity in the intestine of the species that its culture operation could be done more economically by giving them a supplementary diet from indigeneously available raw material particularly from plant origin.

     

In vitro anti-herpetic activity of an aqueous extract from the plant Phyllanthus orbicularis

The Herpesviridae includes at least eight viral species pathogenic for humans, responsible for a wide variety of clinical symptoms. The lack of an effective vaccine and the moderate to high toxicity of the available synthetic anti-herpes compounds emphasises the need for new inhibitors. Several Phyllanthus genus (Euphorbiaceae) members have been widely used in traditional medicine and their biological properties have been intensely studied. In this study we investigated the in vitro antiviral activity of the Cuban-endemic plant Phyllanthus orbicularis H.B.K. against Herpes simplex virus type 1 (HSV-1) and 2 (HSV-2) reference strains and clinical isolates with different sensitivities to acyclovir. The inhibitory activity on Human cytomegalovirus (HCMV) replication was also investigated. The selectivity indexes (SI) found for Ph. orbicularis aqueous extract ranged from 8.7 to 37.6. Studies on the antiviral mechanisms involved revealed that the drug acted at early stages of herpesvirus replication, possibly by producing a virucidal effect, although further inhibition of intracellular replication events could not be ruled out.     

Pathogenic infection and the oxidative defences in plant apoplast

Summary The structural and functional continuum of the plant apoplast is the first site of contact with a pathogen and plays a crucial role in initiation and coordination of many defence responses. In this paper, we present an overview of the involvement of the plant apoplast in plant-pathogen interactions. The process of infection of French bean (Phaseolus vulgaris L.) plants byColletotrichum lindemuthianum is analysed. The ultrastructural features of plant defence responses to fungal infection are then compared with those observed in plants or cell suspensions treated with various elicitors. Changes in cell walls and in whole plant cells responding to infection seem to be highly similar in all systems used. Model systems of French bean and white lupin (Lupinus albus L.) are then utilised to provide some biochemical characteristics of oxidative reactions in the apoplast evoked by elicitor treatment. The species specificity of various mechanisms generating reactive oxygen species is discussed, and some details of pH-dependent H₂O₂-generating activity of peroxidases are demonstrated. As its exocellular nature is an important feature of the oxidative burst, the major consequence of this event, i.e., the oxidative cross-linking of wall components during the papilla formation and strengthening of the walls, is analysed. Finally, the possible involvement of other wall-associated and developmentally regulated H₂O₂-generating mechanisms, like amine and oxalate oxidases, in plant defence is demonstrated. It is concluded that under stress conditions, such apoplastic mechanisms might be employed to increase plants' chances of survival.Abbreviations HR hypersensitive response - IWF intercellular washing fluid - OxO oxalate oxidase - ROS reactive oxygen species - YE elicitor preparation from yeast cell walls     

Phytoremediation potential of transplanted bare-root seedlings of trees for lead/zinc and copper mine tailings

Selecting plant species that can overcome unfavorable conditions and increase the recovery of degraded mined lands remains a challenge. A pot experiment was conducted to evaluate the feasibility of using transplanted tree seedlings for the phytoremediation of lead/zinc and copper mine tailings. One-year-old bare-root of woody species (Rhus chinensis Mill, Quercus acutissima Carruth, Liquidambar formosana Hance, Vitex trifolia Linn. var. simplicifolia Cham, Lespedeza cuneata and Amorpha fruticosa Linn) were transplanted into pots with mine tailings and tested as potential metal-tolerant plants. Seedling survival, plant growth, root trait, nutrient uptake, and metal accumulation and translocation were assessed. The six species grew in both tailings and showed different tolerance level. A. fruticosa was highly tolerant of Zn, Pb and Cu, and grew normally in both tailings. Metal concentrations were higher in the roots than in the shoots of the six species. All of the species had low bioconcentration and translocation factor values. However, R. chinensis and L. formosana had significantly higher translocation factor values for Pb (0.88) and Zn (1.78) than the other species. The nitrogen-fixing species, A. fruticosa, had the highest tolerance and biomass production, implying that it has great potential in the phytoremediation of tailing areas in southern China.     

Induction of Phytohemagglutinin Activity by Arachidonic Acid in in vitro Potato Plants

Tube-grown potato (Solanum tuberosum L., cv. Nevskii) plants treated with arachidonic acid (AA) were used as a model to study the activity of phytohemagglutinins (PHA) during induction of the plant antiviral defense system. Plant treatment with 10^–8 M AA and also their inoculation with potato viruses X, Y, and M resulted in the increased activity of PHAs in potato shoots. The inducer of antiviral resistance behaved as a modulator of the PHA activity providing for its various levels during the development of viral infection. During the development of AA-induced systemic resistance, the level of phytohemagglutinin activity did not essentially depend on the nature of the viral pathogen. We suggested that the mechanism of AA-induced plant antiviral defense was connected with changes in the PHA activity.     

禾穗新缬草,中国败酱科归化植物新记录种

报道了发现于江苏省的败酱科(Valerianaceae)新缬草属(Valerianella Mill.)归化植物新记录种:禾穗新缬草[V.locusta(Linn.)Laterr.]。     

Guatemalan plants extracts as virucides against HIV-1 infection

Prevention methods to avoid transmission of pathogens, including HIV, are crucial in the control of infectious diseases, not only to block epidemic spread but to avoid long-term treatments leading to emergence of resistances and drug associated side effects. Together with vaccine development, the discovery of new virucidal agents represents a research priority in this setting. In the screening of new compounds with antiviral activity, three Guatemalan plant extracts from Justicia reptans, Neurolaena lobata and Pouteria viridis were evaluated with a classic antiviral assay and were found to inhibit HIV replication. This activity was corroborated by an original recombinant virus assay, leading us to perform a deeper study of the virucidal activity. Active fractions were non-toxic in vitro and also inhibited other enveloped viruses. Moreover, these fractions were able to inhibit the transfer of HIV from dendritic cells (DCs) to lymphocytes, that represents the main way of HIV spread in vivo.     

Studies on the rhizosphere mycoflora of broad bean and cotton

Investigations were made on the effect of species of fungi isolated from therhizosphere of broad bean (Vicia faba Linn.) variety Giza I, and cotton (Gossypium barbadense Linn.) variety Giza 47, on plant growth. Broad bean rhizosphere fungi differently affected plant growth.Fusarium moniliforme, Penicillium martensii, Rhizopus stolonifer, andCladosporium sphaerospermum stimulated both root and shoot growth.Aspergillus niger andAlternaria tenuis have an inhibitory effect on plant growth. On the other hand, the rhizosphere fungi of cotton namely,Penicillium cyclopium, Aspergillus terreus, Cephalosporium sp.,Aspergillus niger, Cladosporium sphaerospermum, andFusarium oxysporum stimulated plant growth.     

Carnosine exhibits significant antiviral activity against Dengue and Zika virus

Dengue virus (DENV) and Zika virus (ZIKV) are flaviviruses transmitted to humans by their common vector, Aedes mosquitoes. DENV infection represents one of the most widely spread mosquito‐borne diseases whereas ZIKV infection occasionally re‐emerged in the past causing outbreaks. Although there have been considerable advances in understanding the pathophysiology of these viruses, no effective vaccines or antiviral drugs are currently available. In this study, we evaluated the antiviral activity of carnosine, an endogenous dipeptide (β‐alanyl‐l ‐histidine), against DENV serotype 2 (DENV2) and ZIKV infection in human liver cells (Huh7). Computational studies were performed to predict the potential interactions between carnosine and viral proteins. Biochemical and cell‐based assays were performed to validate the computational results. Mode‐of‐inhibition, plaque reduction, and immunostaining assays were performed to determine the antiviral activity of carnosine. Exogenous carnosine showed minimal cytotoxicity in Huh7 cells and rescued the viability of infected cells with EC₅₀ values of 52.3 and 59.5 μM for DENV2 and ZIKV infection, respectively. Based on the mode‐of‐inhibition assays, carnosine inhibited DENV2 mainly by inhibiting viral genome replication and interfering with virus entry. Carnosine antiviral activity was verified with immunostaining assay where carnosine treatment diminished viral fluorescence signal. In conclusion, carnosine exhibited significant inhibitory effects against DENV2 and ZIKV replication in human liver cells and could be utilized as a lead peptide for the development of effective and safe antiviral agents against DENV and ZIKV.     

Comparison of carbonic anhydrase activity among various species of plantlets

During plant tissue culture, the culture container is small and sealed; the concentration of CO₂ in the microenvironment is relatively low. The plantlet growth is restrained for the shortage of CO₂ in the culture container. Carbonic anhydrase is a zinc-containing metalloenzyme that catalyzes the reversible conversion of bicarbonate to CO₂. The determination of carbonic anhydrase of leaves from Atractylodes lancea (thunb.) DC, Orychophragmus violaceus (L.) O.E. Schulz, Brassica juncea (L.) Czern.et Coss. cv. Luzhousileng, Brassica campestris L. cv. Chuanyou No.8, Brassica napus L cv. Oro, Brassica carinata Braun, Raphanus sativa L. var. raphanistroides Makino and their plantlets indicates that the carbonic anhydrase activity of leaves from both plantlets and fields varies from plant species to plant species, the carbonic anhydrase activity of leaves of Atractylodes lancea (thunb.) DC is the lowest among those plants, and the leaves of all plantlets are lower in carbonic anhydrase activity than the same species of plants from fields. The comparison of the growth rates of those plantlets shows that their relative growth rates are significantly different, plantlets of Atractylodes lancea have the slowest relative growth rate among those plants, and plantlets of Brassica juncea have the greatest relative growth rate. The relationship between RGR of plantlets and their CA activities is a significant linear function. It seems that there was certain correlation between carbonic anhydrase activities of plants and their growth rates. It suggests that in vitro, the greater the carbonic anhydrase activity of plantlet is, the higher its net photosynthetic rate, and the faster its growth rate. Those results offer a foundation to a rational medium choice in plant tissue culture.     

Host factors against plant viruses

Plant virus genome replication and movement is dependent on host resources and factors. However, plants respond to virus infection through several mechanisms, such as autophagy, ubiquitination, mRNA decay and gene silencing, that target viral components. Viral factors work in synchrony with pro-viral host factors during the infection cycle and are targeted by antiviral responses. Accordingly, establishment of virus infection is genetically determined by the availability of the pro-viral factors necessary for genome replication and movement, and by the balance between plant defence and viral suppression of defence responses. Sequential requirement of pro-viral factors and the antagonistic activity of antiviral factors suggest a two-step model to explain plant–virus interactions. At each step of the infection process, host factors with antiviral activity have been identified. Here we review our current understanding of host factors with antiviral activity against plant viruses.     

Evaluation of three aqueous plant extracts and Lamdacot in controlling eggplant fruit borer (Daraba laisalis Wlk.) (Lepidoptera: Pyralidae) in north-eastern Nigeria

Field experiments carried out in Dadinkowa, Gombe State, Nigeria, during 2007 and 2008 cropping seasons evaluated the efficacy of three aqueous plant extracts namely neem (Azadirachta indica A.H.L. Juss.), bitter melon (Momordica balsamina Linn.) and siam weed (Chromolaena odorota (L.) King and Robinson) compared to a conventional insecticide, Lamdacot 500EC, in managing fruit borer (Daraba laisalis Wlk.) attack of eggplants in north-eastern Nigeria. The experiments were laid out in a randomised complete block design replicated four times including controls. The results showed that the application of aqueous extracts (5% w/v concentration) of A. indica and M. balsamina at one-week interval during the fruiting stage was effective and at par with the conventional insecticide, Lamdacot, in reducing eggplant fruit borer infestation and fruit damage, as well as the resulting increase in fruit yield. Farmers can therefore adopt the practice of applying 5% w/v concentration of the above aqueous plant extracts at weekly intervals to control fruit borer attack of eggplants in the north-eastern region of Nigeria.