A New Approach to Natural Products Discovery Exemplified by the Identification of Sulfated Nucleosides in Spider Venom

Using a new approach based on the NMR spectroscopic analysis of the entire, unpurified spider venom,we identified a family of unusual sulfated nucleoside derivatives from the venom of the hobo spider,Tegenaria agrestis.These compounds are ribonucleoside mono- and disulfates derived from guanosine and xanthosine, some of which are glycosylated, bearing one or two D-fucose units. The use of NMR spectroscopy to characterize the unfractionated venom was central to the discovery of this heretofore overlooked class of venom components.

Effect of Different Levels of Nitrogen and Phosphorus on the Phenology and Yield of Maize Varieties

An experiment was conducted at Malakabad (Gadera) Dargai Malak and KPK to study the effect of different levels of nitrogen and phosphorus on the yield of maize varieties in randomize complete block design with split plot arrangement. Different fertilization treatments (0:0, 100:0, 100:50, 100:100, 150:0, 150:50, 150:100, 150:150 N:P kg·ha-1) were assigned to main plot while, maize varieties (Azam, Jalal and local) were kept in sub-plots. Data regarding emergence m-2, days to emergence, days to tasseling, days to silking, number of cobs plant-1, plant height, grains cob-1, 1000-grain weight and grain yield were recorded. Emergence m-2, days to emergence, days to tasseling, days to silking, plant ha-1 at harvest were not significantly affected by different levels of nitrogen and phosphorus while number of cob plant-1, thousand grains weight, plant height, grains cob-1 and grain yield were significantly affected. Maximum grain yield (5356 kg·ha-1) was recorded in Jalal variety, when it was fertilized with 150:100 N:P kg·ha-1. Of the factors included in this study, maize cultivars and NP fertilization treatments were dominant in determining grain yield as well as its related components, suggesting that cultivar selection and optimum fertilization are effective strategies to improve grain yield. However, multiplication and multi-year studies are required to test these results using different cultivars under varying edaphic and climatic conditions.

Morphological phylogeny among 15 accessions of bamboos growing in Kokrajhar district of the Bodoland Territorial Area Districts,Assam

Bamboo is nature＇s wonderful gift historically associated with the rural population of the Bodoland Territorial Area Districts.However,indiscriminate use of the resource and the ambiguity in the identification of bamboos in the absence of flowering characters pose a potential risk to the bamboo germplasm.Therefore,we considered revising the taxonomic positions and phylogenetic relationships among 15 tropical bamboo species using 35 key morphological descriptors（MD） to assess the reliability of vegetative characters in identifying species.The phylogenetic tree constructed from the similarity matrix,derived from an unweighted pair group method of analysis（UPGMA） of the 35 MDs,marginally deviated from the conventional taxonomic positions of the bamboo species.While the two varieties,one forma of Bambusa vulgaris（var.Vittata,var.Vulgaris,fo.Waminii） and two species of the genus Dendrocalamus（D.giganteus and D.hamiltonii）clustered together in a single clade,and D.strictus was distantly placed from their congeners.This discrepancy with the conventional classification might have ensued since only vegetative characters such as culm anatomy,culm sheath,leaf,and leaf sheath were considered in the present study.While the phylogenetic relationship among the 15 tropical bamboos（computed from exhaustive MDs）grossly corroborate the conventional taxonomic grouping,a molecular-marker-based multidisciplinary approach should resolve the remaining conflicts in bamboo identification.

Mating Disruption of Striped Rice Stem Borer: Importance of Early Deployment of Dispensers and Impact on Airborne Pheromone Concentration

Mating disruption(MD)is an effective environmentally-friendly control method against the striped rice stem borer(RSB),Chilo suppressalis(Lepidoptera:Crambidae).In this study,the current MD dispensers release the pheromone exponentially,with higher initial release rates that decrease throughout the time.To adjust the timing of dispensers'deployment and evaluate the importance of controlling the early first or the second male flight,field trials were carried out to test the efficacy of two strategies:the early dispenser deployment prior to the first male flight(May)and the late deployment prior to the second flight(June).The early dispenser deployment was more effective in reducing plant damage inflicted by RSB when assessed at harvest.However,neither of these strategies was able to inhibit the male catches of the third flight due to the dispensers5 depletion.Attending to the airborne pheromone concentrations obtained,around 1.60 ng/m3 were capable to inhib社C.suppressalis male flight effectively.

Evolutionary ecology of microsporidia associated with the invasive ladybird Harmonia axyridis

Invasive species are characterized by the rapid growth and spread of their populations after establishing a foothold in new habitats, and there are now many examples of such species negatively affecting biodiversity and the economy. It is unclear why some species can become successful invaders, whereas most （even if closely related） remain noninvasive. We previously proposed a hypothesis that parasites associated with invading species can promote their invasive success if they are harmless toward the invaders but harmful to their competitors and/or predators in the newly colonized habitat. Here we discuss whether microsporidia that have recently been discovered in the invasive ladybird Harmonia axyridis contribute to its invasive success. We show that all H. axyridis beetles sourced from diverse collection sites all over the world carry abundant microsporidia. This suggests that both native and invasive H. axyridis populations are associated with these tolerated parasites, which were likely to have existed in native populations before expansion rather than being acquired in newly colonized areas. We describe the pathogenesis of the microsporidia during different developmental stages of H. axyridis and we address the possibility that the predation of its infected eggs and larvae by competing native ladybird species may lead to their infection and ultimately to their decline. Finally, we discuss our initial hypothesis： microsporidia that are tolerated by an invasive vector insect can be active against susceptible native competitors and/or predator species.

Involvement of CYP347W1 in neurotoxin 3-nitropropionic acid-based chemical defense in mustard leaf beetle Phaedon cochleariae

Chrysomelina beetlesstore 3-nitropropionic acid in form of a pretoxin,isoxazolin-5-one glucoside-conjugated ester,to protect themselves against predators.Here we identified a cytochrome P450 monooxygenase,CYP347W1,to be involved in the production of the 3-nitropropionic acid moiety of the isoxazolin-5-one glucoside ester.Knocking down CYP347W1 led to a significant depletion in the concentration of the isoxazolin-5-one glucoside ester and an increase in the concentration of the isoxazolin-5-one glucoside in the larval hemolymph.Enzyme assays with the heterologously expressed CYP347W1 showed freeβ-alanine was not the direct substrate.Homology modeling indicated thatβ-alanine-CoA ester can fit into CYP347W1’s active site.Furthermore,we proved that Phaedon cochleariae eggs are not able to de novo synthesize 3-NPA,although both isoxazolin-5-one glucoside and its 3-NPA-conjugated ester are present in the eggs.These results provide direct evidence for the involvement of CYP347W1 in the biosynthesis of a P.cochleariae chemical defense compound.

Dissolved oxygen in aeration-driven piezo-catalytic for antibiotics pollutants removal in water

The misuse of antibiotics and oxygen-lacking in aquaculture causes serious water environmental problems.Herein,a piezoelectic odd-layered MoS_(2)is prepared and applied to piezo-catalytic remove tinidazole(TNZ)and other antibiotic pollutants with aeration as a piezo-driving force.About 89.6%of TNZ can be degraded by MoS_(2)under aeration in the presence of dissolved oxygen with a reaction rate constant of0.15 min^(-1),which is 2.4 times higher than that under N2atmosphere and quiescence conditions.Quenching experiments and electron paramagnetic resonance(EPR)tests identify that singlet oxygen(^(1)O_(2))and superoxide radical(O_(2)^(·-))are dominant reactive oxygen species in MoS_(2)/aeration system.These results demonstrate that MoS2can trigger a piezoelectric effect and produce charge carriers to generate reactive oxygen species with dissolved oxygen(DO)for contaminant degradation with the turbulence and water bubbles rupture driven by aeration.

Enhanced persulfate activation process by magnetically separable catalysts for water purification:A review

In recent years,persulfate(PS)-based advanced oxidation processes(AOPs)have become a hot research topic for degrading environmental pollutants due to their excellent oxidation capacity,selectivity,and stability.PS-AOPs can generate sulfate radicals(SO^(·-)_(4))with strong oxidation ability,but single PS produces limited or no radicals.Therefore,activation of PS by energy input or catalyst dosing is used to improve its oxidation performance.However,the addition of disposable catalyst not only causes a waste of resources,but also may lead to secondary pollution.Therefore,magnetically separable catalysts for activating PS have received widespread attention due to their reusability.Although there are few literature reviews on the activation of PS by carbon-or iron-based magnetic materials,the mechanism analysis of the activation of PS by magnetic materials to degrade pollut-ants is not deep enough,and the discussion of material types is not comprehensive and detailed.Moreover,the discussion of magnetic materials in terms of recycling properties is lacking.Therefore,this review firstly sum-marizes and analyzes the mechanism of magnetically separable catalysts activating PS to degrade pollutants.Then,the research progress of zero-valent iron(ZVI,Fe^(0))-based,iron oxide-based,bimetallic oxide-based,and other magnetically separable catalyst is introduced,and the tailoring engineering approaches and reusability of magnetically separable catalysts are discussed.Finally,some possible material optimization suggestions are proposed in this paper.In conclusion,this review is expected to provide useful insights for improving the per-formance and reusability of magnetically separable materials activated PS in the future.

Revisiting the trail pheromone components of the red imported fire ant, Solenopsis invicta Buren

Ants use species-specific trail pheromones to coordinate their sophisticated foraging behavior.During the past decades,many trail pheromone components with various structures have been identified in ants,including the red imported fire ant,Solenopsis invicta,a notorious invasive species worldwide.Four compounds,Z,E-(ZEF)and E,E-α-farnesene(EEF),Z,E-(ZEHF)and E,E-α-homofarnesene(EEHF),have been reported as components of S.invicta trail pheromone.However,another study reported an analog ofα-farnesene,Z,Z,Z-allofarnesene,as a key trail pheromone component.These contrasting results caused some uncertainty about the trail pheromone composition in S.invicta.In this study,we synthesized ZEF and EEF,ZEHF and EEHF,and reanalyzed the chemicals in the Dufour gland extract and in the trail pheromone fraction of S.invicta worker body extract.The reported isomers of farnesene and homofarnesene were detected and showed trail-following activity,with ZEF as the major compound,while no allofarnesene was found,neither in the Dufour gland extract nor in the whole-body extract.Our results confirm ZEF and EEF,ZEHF and EEHF as trail pheromone components of S.invicta.

Unraveling the serial glycosylation in the biosynthesis of steroidal saponins in the medicinal plant Paris polyphylla and their antifungal action

Sugar-sugar glycosyltransferases play important roles in constructing complex and bioactive saponins.Here,we characterized a series of UDP-glycosyltransferases responsible for biosynthesizing the branched sugar chain of bioactive steroidal saponins from a widely known medicinal plant Paris polyphylla var.yunnanensis.Among them,a 2'-O-rhamnosyltransferase and three 6'-O-glucosyltrasferases catalyzed a cascade of glycosylation to produce steroidal diglycosides and triglycosides,respectively.These UDP-glycosyltransferases showed astonishing substrate promiscuity,resulting in the generation of a panel of 24 terpenoid glycosides including 15 previously undescribed compounds.A mutant library containing 44 variants was constructed based on the identification of critical residues by molecular docking simulations and protein model alignments,and a mutant UGT91AH1^(Y187A)with increased catalytic efficiency was obtained.The steroidal saponins exhibited remarkable antifungal activity against four widespread strains of human pathogenic fungi attributed to ergosterol-dependent damage of fungal cell membranes,and 2'-O-rhamnosylation appeared to correlate with strong antifungal effects.The findings elucidated the biosynthetic machinery for their production of steroidal saponins and revealed their potential as new antifungal agents.

Mechanisms of Optimal Defense Patterns in Nicotiana attenuata: Flowering Attenuates Herbivory-elicited Ethylene and Jasmonate Signaling

To defend themselves against herbivore attack, plants produce secondary metabolites, which are variously inducible and constitutively deployed, presumably to optimize their fitness benefits in light of their fitness costs. Three phytohormones, jasmonates （JA） and their active forms, the JA-isoleucine （JA-Ile） and ethylene （ET）, are known to play central roles in the elicitation of induced defenses, but little is known about how this mediation changes over ontogeny. The Optimal Defense Theory （ODT） predicts changes in the costs and benefits of the different types of defenses and has been usefully extrapolated to their modes of deployment. Here we studied whether the herbivore-induced accumulation of JA, JA-Ile and ET changed over ontogeny in Nicotiana attenuata, a native tobacco in which inducible defenses are particularly well studied. Herbivore-elicited ET production changed dramatically during six developmental stages, from rosette through flowering, decreasing with the elongation of the first corollas during flower development. This decrease was largely recovered within a day after flower removal by decapitation. A similar pattern was found for the herbivore-induced accumulation of JA and JA-Ile. These results are consistent with ODT predictions and suggest that the last steps in floral development control the inducibility of at least three plant hormones, optimizing defense-growth tradeoffs.

MAPK signaling： A key element in plant defense response to insects

Insects have long been the most abundant herbivores, and plants have evolved sophisticated mechanisms to defend against their attack, In particular, plants can perceive specific patterns of tissue damage associated with insect herbivory. Some plant species can perceive certain elicitors in insect oral secretions （OS） that enter wounds during feeding, and rapidly activate a series of intertwined signaling pathways to orchestrate the biosynthesis of various defensive metabolites. Mitogen-activated protein kinases （MAPKs）, common to all eukaryotes, are involved in the orchestration of many cellular processes, including development and stress responses. In plants, at least two MAPKs, salicylic acid-induced protein kinase （SIPK） and wound-induced protein kinase （WlPK）, are rapidly activated by wounding or insect 0S; importantly, genetic studies us- ing transgenic or mutant plants impaired in MAPK signaling indicated that MAPKs play critical roles in regulating the herbivory-induced dynamics of phytohormones, such as jasmonic acid, ethylene and salicylic acid, and MAPKs are also required for transcriptional activation of herbivore defense-related genes and accumulation of defensive metabolites. In this review, we summarize recent developments in understanding the functions of MAPKs in plant resistance to insect herbivores.

Silencing NOA1 Elevates Herbivory-Induced Jasmonic Acid Accumulation and Compromises Most of the Carbon-Based Defense Metabolites in Nicotiana attenuata

Nitric oxide-associated protein 1 （NOA1） is involved in various abiotic stress responses and is required for plant resistance to pathogen infections. However, the role of NOA1 in plant-herbivore interactions has not been explored. We created NOA1-silenced Nicotiana attenuata plants （irNaNOA1）. Compared with wild-type （WT） plants, irNaNOA1 plants had highly decreased photosynthesis rates. We further examined various traits important for plant defense against its specialist herbivore Manduca sexta by treating WT and irNaNOA1 plants with mechanical wounding and M. sexta oral secretions （OS）. NOA1-silenced plants showed elevated levels of herbivory-induced jasmonic acid （JA）, but decreased JA-isoleucine conjugate （JA-Ile） levels. The decreased JA-Ile levels did not result from compromised JAR （jasmonic acid resistant） activity in irNOA1 plants. Moreover, nitrogen-rich defensive compounds, nicotine and trypsin proteinase inhibitors, did not differ between WT and irNaNOA1 plants. In contrast, concentrations of most carbon-based defensive compounds were lower in these plants than in WT plants, although the levels of chlorogenic acid were not changed. Therefore, silencing NOA1 alters the allocation of carbon resources within the phenylpropanoid pathway. These data suggest the involvement of NOA1 in N. attenuata’s defense against M. sexta attack, and highlight its role in photosynthesis, and biosynthesis of jasmonates and secondary metabolites.

Mutation of the Arabidopsis Calmodulin-Like Protein CML37 Deregulates the Jasmonate Pathway and Enhances Susceptibility to Herbivory

Throughout their life, plants are challenged by various abiotic and biotic stress factors. Among those are attacks from herbivorous insects. The molecular mechanisms underlying the detection of herbivores and the subsequent signal transduction are not well understood. As a second messenger, fluxes in intracellular Ca2＋ levels play a key role in mediating stress response pathways. Ca2＋ signals are decoded by Ca2＋ sensor proteins such as calmodulin-like proteins （CMLs）. Here, we demonstrate that recombinant CML37 behaves like a Ca2＋ sensor in vitro and, in Arabidopsis, AtCML37 is induced by mechanical wounding as well as by infestation with larvae of the generalist lepidopteran herbivore Spodoptera littoralis. Loss of function of CML37 led to a better feeding performance of larvae suggesting that CML37 is a positive defense regulator. No herbivory-induced changes in secondary metabolites such as glucosinolates or flavonoids were detected in cml37 plants, although a significant reduction in the accumulation of jasmonates was observed, due to reduced expression of JAR1 mRNA and cellular enzyme activity. Consequently, the expression of jasmonate-responsive genes was reduced as well. Summarizing, our results suggest that the Ca2＋ sensor protein, CML37, functions as a positive regulator in Ca2＋ signaling during herbivory, connecting Ca2＋ and jasmonate signaling.

Involvement of sweet pepper Ca LOX2 in jasmonate-dependent induced defence against Western flower thrips

Insect herbivory can seriously hinder plant performance and reduce crop yield. Thrips are minute cell-content-feeding insects that are important vectors of viral plant pathogens, and are serious crop pests. We investigated the role of a sweet pepper (Capsicum annuum) lipoxygenase gene, CaLOX2, in the defense of pepper plants against Western flower thrips (Frankliniella occidentalis). This was done through a combination of in-silico, transcrip-tional, behavioral andchemicalanalyses.Our datashowthat CaLOX2 is involved in jasmonic acid (JA) biosynthesis and mediates plant resistance. Expression of the JA-related marker genes, CaLOX2 and CaPIN II, was induced by thrips feeding. Silencing of CaLOX2 in pepper plants through virus-induced gene silencing (VIGS) resulted in low levels of CaLOX2 transcripts, as well as significant reduction in the accumulation of JA, and its derivatives, upon thrips feeding compared to control plants. CaLOX2-silenced pepper plants exhibited enhanced susceptibility to thrips. This indicates that CaLOX2 mediates JA-dependent signaling, resulting in defenseagainstthrips. Furthermore,exogenous application of JA to pepper plants increased plant resistance to thrips, constrained thrips population development and made plants less attractive to thrips. Thus, a multidisciplinary approach shows that an intact lipoxygenase pathway mediates various components of sweet pepper defense against F. occidentalis.

Effect of ferric and bromide ions on the formation and speciation of disinfection byproducts during chlorination

The effects of ferric ion, pH, and bromide on the formation and distribution of disinfection byproducts （DBPs） during chlorination were studied. Two raw water samples from Huangpu River and Yangtze River, two typical drinking water sources of Shanghai, were used for the investigation. Compared with the samples from Huangpu River, the raw water samples from Yangtze River had lower content of total organic carbon （TOC） and ferric ions, but higher bromide concentrations. Under controlled chlorination conditions, four trihalomethanes （THMs）, nine haloacetic acids （HAAs）, total organic halogen （TOX） and its halogen species fractions, including total organic chlorine （TOC1） and total organic bromide （TOBr）, were determined. The results showed that co-existent ferric and bromide ions significantly promoted the formation of total THMs and HAAs for both raw water samples. Higher concentration of bromide ions significantly changed the speciation of the formed THMs and HAAs. There was an obvious shift to brominated species, which might result in a more adverse influence on the safety of drinking water. The results also indicated that high levels of bromide ions in raw water samples produced higher percentages of unknown TOBr.

Role of Arabidopsis UV RESISTANCE LOCUS 8 in Plant Growth Reduction under Osmotic Stress and Low Levels of UV-B

In high-light environments, plants are exposed to different types of stresses, such as an excess of UV-B, but also drought stress which triggers a common morphogenic adaptive response resulting in a general reduction of plant growth. Here, we report that the Arabidopsis thaliana UVRESISTANCE LOCUS 8 （UVR8） gene, a known regulator of the UV-B morphogenic response, was able to complement a Saccharomyces cerevisiae osmo-sensitive mutant and its expression was induced after osmotic or salt stress in Arabidopsis plants. Under low levels of UV-B, plants overexpressing UVR8 are dwarfed with a reduced root development and accumulate more flavonoids compared to control plants. The growth defects are mainly due to the inhibition of cell expansion. The growth inhibition triggered by UVR8 overexpression in plants under low levels of UV-B was exacerbated by mannitol-induced osmotic stress, but it was not significantly affected by ionic stress. In contrast, uvr8-6 mutant plants do not differ from wild-type plants under standard conditions, but they show an increased shoot growth under high-salt stress. Our data suggest that UVR8-mediated accumulation of flavonoid and possibly changes in auxin homeostasis are the underlying mechanism of the observed growth phenotypes and that UVR8 might have an important role for integrating plant growth and stress signals.

Circadian clock component, LHY, tells a plant when to respond photosynthetically to light in nature

The circadian clock is known to increase plant growth and fitness, and is thought to prepare plants for photosynthesis at dawn and dusk; whether this happens in nature was unknown. We transformed the native tobacco, Nicotiana attenuata to silence two core clock components, NaLHY （irLHY） and NaTOC1 （irTOC1）. We characterized growth and light- and dark-adapted photosynthetic rates （Ac） throughout a 24 h clay in empty vector-transformed （EV）, irLHY, and irTOC1 plants in the field, and in NaPhyA-and NaPhyB1-silenced plants in the glasshouse. The growth rates of irLHY plants were lower than those of EV plants in the field. While irLHY plants reduced Ac earlier at dusk, no differences between irLHY and EV plants were observed at dawn in the field, irLHY, but not EV plants, responded to light in the night by rapidly increasing Ac. Under controlled conditions, EV plants rapidly increased Ac in the day compared to dark-adapted plants at night; irLHY plants lost these time-dependent responses. The role of NaLHY in gating photosynthesis is independent of the light-depen- dent reactions and red light perceived by NaPhyA, but not NaPhyB1. In summary, the circadian clock allows plants not to respond photosynthetically to light at night by anticipating and gating red light-mediated in native tobacco.

DICER-like Proteins and Their Role in Plant-herbivore Interactions in Nicotiana attenuata

DICER-like （DCL） proteins produce small RNAs that silence genes involved in development and defenses against viruses and pathogens. Which DCLs participate in plant-herbivore interactions remains unstudied. We identified and stably silenced four distinct DCL genes by RNAi in Nicotiana attenuata （Torrey ex. Watson）, a model for the study of plant-herbivore interactions. Silencing DCL1 expression was lethal. Manduca sexta larvae performed significantly better on ir-dcl3 and ir-dcl4 plants, but not on ir-dcl2 plants compared to wild type plants. Phytohormones, defense metabolites and microarray analyses revealed that when DCL3 and DCL4 were silenced separately, herbivore resistance traits were regulated in distinctly different ways. Crossing of the lines revealed complex interactions in the patterns of regulation. Single ir-dcl4 and double ir-dcl2 ir-dcl3 plants were impaired in JA accumulation, while JA- Ile was increased in ir-dcl3 plants. Ir-dcl3 and ir-dcl4 plants were impaired in nicotine accumulation; silencing DCL2 in combination with either DCL3 or DCL4 restored nicotine levels to those of WT. Trypsin proteinase inhibitor activity and transcripts were only silenced in ir-dcl3 plants. We conclude that DCL2/3/4 interact in a complex manner to regulate anti-herbivore defenses and that these interactions significantly complicate the already challenging task of understanding smRNA function in the regulation of biotic interactions.