The oral secretions of insect herbivores are complex mixtures of organic and inorganic solutes and enzymes that are deposited onto plant tissues during the feeding process.Some specific components of insect oral secre...The oral secretions of insect herbivores are complex mixtures of organic and inorganic solutes and enzymes that are deposited onto plant tissues during the feeding process.Some specific components of insect oral secretions have been shown to confer important functions in mediating plant–insect interactions at the molecular level.In this review,we examined the biochemical studies of insect oral secretions to summarize the current knowledge of their compositions.We then moved beyond the functional studies of components of oral secretions,and focused on the literature that pinpointed specific molecular targets of these compounds.Finally,we highlighted the investigations of oral secretion components in the context of insect physiology,which shed light on the potential evolutionary trajectory of these multi-functional molecules.展开更多
Insect herbivory is ubiquitous in various ecosystems,and directly influences the growth and survival of individual plants,especially during their vulnerable early life stages like the seedling phase.This,in turn,exert...Insect herbivory is ubiquitous in various ecosystems,and directly influences the growth and survival of individual plants,especially during their vulnerable early life stages like the seedling phase.This,in turn,exerts a significant influence on forest community diversity and structure,as well as ecosystem function and stability.Notable variation in herbivory has been detected both among and within plant species.For decades,many hypotheses have been proposed to explain such variations,including both biotic and abiotic variables.However,most studies have considered only one or several of these hypotheses by focusing on a few potential variables,and their results were usually inconsistent;thus,the factors driving herbivory remain unclear.In this study,we examined leaf herbivory by insects of woody species seedlings in a subtropical forest in southwestern China over two seasons.In total,24 potential variables that represented abiotic resource availability,characters of individual seedlings,conspecific and heterospecific species,and the whole seedling community were selected to test several commonly discussed alternative herbivory hypotheses.Overall,our findings showed that the plant apparency hypothesis was more supported than the other hypotheses in explaining insect seedling herbivory.Our results further indicated that the mechanisms and causes of insect herbivory are complex,multifactorial,species-specific and vary with seasons,indicating that there may be no uniform rules in explaining herbivory for all seedlings.Consequently,such complexity may play an important role in promoting species coexistence and biodiversity maintenance in seedling communities,which may further translate into the following generation of saplings or even adult communities.Changes in the community of insect herbivores and/or variables influencing insect herbivory,may disrupt stability of the original seedling community,thus affecting the regeneration and development of the entire forest community.Therefore,we suggest that issues related to insect herbivory should be considered when developing forest management and conservation.展开更多
Parasitic plants and their hosts communicate through haustorial connections.Nutrient deficiency is a common stress for plants,yet little is known about whether and how host plants and parasites communicate during adap...Parasitic plants and their hosts communicate through haustorial connections.Nutrient deficiency is a common stress for plants,yet little is known about whether and how host plants and parasites communicate during adaptation to such nutrient stresses.In this study,we used transcriptomics and proteomics to analyze how soybean(Glycine max)and its parasitizing dodder(Cuscuta australis)respond to nitrate and phosphate deficiency(-N and-P).After-N and-P treatment,the soybean and dodder plants exhibited substantial changes of transcriptome and proteome,although soybean plants showed very few transcriptional responses to-P and dodder did not show any transcriptional changes to either-N or-P.Importantly,large-scale interplant transport of mRNAs and proteins was detected.Although the mobile mRNAs only comprised at most 0.2%of the transcriptomes,the foreign mobile proteins could reach 6.8%of the total proteins,suggesting that proteins may be the major forms of interplant communications.Furthermore,the interplant mobility of macromolecules was specifically affected by the nutrient regimes and the transport of these macromolecules was very likely independently regulated.This study provides new insight into the communication between host plants and parasites under stress conditions.展开更多
Phytoremediation is a sustainable remedial approach for removing benzene from environment.Plant associated bacteria could ameliorate the phytotoxic effects of benzene on plant,although the specificity of these interac...Phytoremediation is a sustainable remedial approach for removing benzene from environment.Plant associated bacteria could ameliorate the phytotoxic effects of benzene on plant,although the specificity of these interactions is unclear.Here,we used proteomics approach to gain a better understanding of the mechanisms involved in plant-bacteria interactions.Plant associated bacteria was isolated and subsequently inoculated into the sterilized Helianthus annuus,and the uptake rates of benzene by these inoculated plants were evaluated.At the end of the experiment,leaves and roots proteins were analyzed.The results showed inoculated H.annuus with strain EnL3 removed more benzene than other treatments after 96 h.EnL3 was identified as Enterobacter sp.according to 16S rDNA analysis.Based on the comparison of proteins,62 proteins were significantly up or down regulated in inoculated leaves,while 35 proteins were significantly up or down regulated in inoculated roots.Furthermore,there were 4 and 3 identified proteins presented only in inoculated H.annuus leaves and roots,respectively.These proteins involved in several functions including transcription and translation,photosynthesis,and stress response.The network among anti-oxidant defense system,protein synthesis,and photosynthetic electron transfer are involved in collaboratively activate the benzene uptake and stress tolerance in plant.展开更多
The ＂XIV International Symposium on Iron Nutrition and Interactions in Plants＂ （14th ISINIP） will be held in Beijing, China, on 11-15 October 2008. It will be held together with the Annual Meeting of HarvestPlus-C...The ＂XIV International Symposium on Iron Nutrition and Interactions in Plants＂ （14th ISINIP） will be held in Beijing, China, on 11-15 October 2008. It will be held together with the Annual Meeting of HarvestPlus-China. The joint symposium will provide opportunities to scientists from soil sciences, plant nutrition, plant breeding, animal and human nutrition around the world to communicate their new results and experiences in studying iron nutrition of plants, animal and human for a better understanding of the mechanisms of iron from soils, over plants to animals and human beings. The scientific topics of the symposium are as follows：展开更多
Objective:To document ethnobotanical informations of useful woody plant species in the region of Kotli,Azad Kashmir.Methods:An ethnobotanical survey was conducted in Kotli.Data were collected by interview and semi str...Objective:To document ethnobotanical informations of useful woody plant species in the region of Kotli,Azad Kashmir.Methods:An ethnobotanical survey was conducted in Kotli.Data were collected by interview and semi structured questionnaire from selected local informants and traditional practitioners as well as by field assessment.Results:The present study documented the etnobotanical uses of 33 woody plant species.Most of the species have been used for dual purpose.Only 5 species are used for one purpose.Study revealed all species have medicinal value,among which 21 were used as fuel wood species,16 as fodder species,4 as timber wood species,12 as edible fruit species,6 as fence or hedge plant,7 as ornamental species and 12 species had other uses.Conclusions:Medicinal plants are still widely used for health care by locals of Kotli.Some species of woodlands seem to be vulnerable to overcollection and deforestation.As the young generation is diverted toward allelopathic medicines,ethnobotanical knowledges of important medicinal plants are restricted to the old people only.It is suggested to close the forest of district Kotli for next two to three decades for the conservation of plant biodiversity.展开更多
Exotic plant invasion is a growing concern in the conservation and management of indigenous arid land ecosystems. By creating areas of ameliorated microclimates and fertile soil below their canopies, perennial plants ...Exotic plant invasion is a growing concern in the conservation and management of indigenous arid land ecosystems. By creating areas of ameliorated microclimates and fertile soil below their canopies, perennial plants might influence exotic annual plant invasions. We conducted a quantitative literature review of studies that compared exotic annual plant abundance among native perennial plant species and interspace （open areas） microsites in North America＇s Mojave Desert, where exotic plant invasion has corresponded with increasing extent of wildfire and broad-scale ecosystem transformation. Ten studies compared exotic annual plant abundance between inter- spaces and below a total of 36 native perennial species. These studies revealed that： （1） With few exceptions, most native perennial species supported a greater abundance of exotic annuals than interspaces, indicating overall facilitation of exotic species by native perennials. （2） Exotic species abundance varied by orders of magnitude among native perennial species, with some perennial species harboring amounts of exotics similar to interspaces. （3） Distributions of dominant exotic species varied, where Bromus rubens displayed a greater affinity for below-perennial microsites than did Schismus spp. and Erodium cicutarium that often were most abundant in interspaces. Results suggest that the degree of facilitation of exotic plants warrants consideration when selecting native perennial species for revegetation and restoration projects.展开更多
Nitrogen is an essential component in forest ecosystem nutrient cycling.Nitrogen fractions,such as dissolved nitrogen,ammonium,nitrate,and microbial biomass nitrogen,are sensitive indicators of soil nitrogen pools whi...Nitrogen is an essential component in forest ecosystem nutrient cycling.Nitrogen fractions,such as dissolved nitrogen,ammonium,nitrate,and microbial biomass nitrogen,are sensitive indicators of soil nitrogen pools which affect soil fertility and nutrient cycling.However,the responses of nitrogen fractions in forest soils to organic mulching are less well understood.The rhizosphere is an important micro-region that must be considered to better understand element cycling between plants and the soil.A field investigation was carried out on the effect of mulching soil in a 15-year-old Ligustrum lucidum urban plantation.Changes in total nitrogen and nitrogen fractions in rhizosphere and bulk soil in the topsoil(upper 20 cm)and in the subsoil(20-40 cm)were evaluated following different levels of mulching,in addition to nitrogen contents in fine roots,leaves,and organic mulch.The relationships between nitrogen fractions and other measured variables were analysed.Organic mulching had no significant effect on most nitrogen fractions except for the rhizosphere microbial biomass nitrogen(MBN),and the thinnest(5 cm)mulching layer showed greater effects than other treatments.Rhizosphere MBN was more sensitive to mulching compared to bulk soil,and was more affected by soil environmental changes.Season and soil depth had more pronounced effects on nitrogen fractions than mulching.Total nitrogen and dissolved nitrogen were correlated to soil phosphorus,whereas other nitrogen fractions were strongly affected by soil physical properties(temperature,water content,bulk density).Mulching also decreased leaf nitrogen content,which was more related to soil nitrogen fractions(except for MBN)than nitrogen contents in either fine roots or organic mulch.Frequent applications of small quantities of organic mulch contribute to nitrogen transformation and utilization in urban forests.展开更多
Plant roots interact with diverse fungi that are essential for maintaining the productivity and sustainability of pasture ecosystems,but how these root-associated fungi(RAF)differ between forage species and how they r...Plant roots interact with diverse fungi that are essential for maintaining the productivity and sustainability of pasture ecosystems,but how these root-associated fungi(RAF)differ between forage species and how they respond to nutrient enrichment and fungicide application are not well understood.Here,we constructed an 11-year experiment involving fungicide application(with or without)nested within four levels of experimental nitrogen(N)addition treatments in an alpine pasture,and the RAF communities,root traits,tissue nutrients,and shoot biomass of two dominant forage species(Carex capillifolia and Elymus nutans)were analyzed.The RAF community composition showed striking differences between the plant species and was strongly affected by both N addition level and fungicide applications.Fungicide,but not N application,dramatically reduced the RAF richness of all functional guilds in both plant species,and fungicide also simplified the co-occurrence network of the RAF for C.capillifolia.The RAF community correlated strongly with root traits,whereas their relationships became weakened or even vanished at the level of the individual plant species.The importance of RAF to plant nutrients and productivity varied between plant species,with significant contributions in C.capillifolia but not in E.nutans.This is the first report elucidating the long-term effect of fungicides on RAF in alpine pastures,and our findings emphasize the host-specific responses of RAF community structure and function to anthropogenic disturbances.展开更多
Sound contains mechanical signals that can promote physiological and biochemical changes in plants.Insects produce different sounds in the environment,which may be relevant to plant behavior.Thus,we evaluated whether ...Sound contains mechanical signals that can promote physiological and biochemical changes in plants.Insects produce different sounds in the environment,which may be relevant to plant behavior.Thus,we evaluated whether signaling cascades are regulated differently by ecological sounds and whether they trigger molecular responses following those produced by herbivorous insects.Soybean plants were treated with two different sounds:chewing herbivore and forest ambient.The responses were markedly distinct,indicating that sound signals may also trigger specific cascades.Enzymes involved in oxidative metabolism were responsive to both sounds,while salicylic acid(SA)was responsive only to the chewing sound.In contrast,lipoxygenase(LOX)activity and jasmonic acid(JA)did not change.Soybean Kunitz trypsin inhibitor gene(SKTI)and Bowman-Birk(BBI)genes,encoding for protease inhibitors,were induced by chewing sound.Chewing sound-induced high expression of the pathogenesis-related protein(PR1)gene,confirming the activation of SA-dependent cascades.In contrast,the sound treatments promoted modifications in different branches of the phenylpropanoid pathway,highlighting a tendency for increased flavonols for plants under chewing sounds.Accordingly,chewing sounds induced pathogenesis-related protein(PR10/Bet v-1)and gmFLS1 flavonol synthase(FLS1)genes involved in flavonoid biosynthesis and flavonols.Finally,our results propose that plants may recognize herbivores by their chewing sound and that different ecological sounds can trigger distinct signaling cascades.展开更多
Garlic is a most important medicinal herb belonging to the family Liliaceae. Both its leaves and bulb are edible. The current study was based on evaluating the growth promoting potential of plant growth promoting rhiz...Garlic is a most important medicinal herb belonging to the family Liliaceae. Both its leaves and bulb are edible. The current study was based on evaluating the growth promoting potential of plant growth promoting rhizobacteria (PGPR) on garlic (Allium sativum L.) growth and biochemical contents. Garlic cloves were inoculated with 3 kinds of PGPRs, Pseudomonas putida (KX574857), Pseudomonas stutzeri (Kx574858) and Bacillus cereus (ATCC14579) at 10<sup>8</sup> cells/mL prior to sowing. Under natural conditions, plants were grown in the net house. The PGPR significantly enhanced % germination, leaf and root growth and their biomass also increased the diameter of bulb and fresh and dry weight. The flavonoids, phenolics, chlorophyll, protein and sugar content were also significantly increased due to PGPR inoculation. The Pseudomonas stutzeri was found most effective for producing longer leaves with moderate sugar, high flavonoids (129%) and phenolics (263%) in bulb over control (Tap). The Pseudomonas putida exhibited a maximum increase in bulb diameter and bulb biomass with maximum phenolics and flavonoid contents.展开更多
Ralstonia solanacearum is an important model phytopathogenic bacterium that causes bacterial wilt disease on many plant species and leads to serious economic losses. The interactions between R. solanacearum and host p...Ralstonia solanacearum is an important model phytopathogenic bacterium that causes bacterial wilt disease on many plant species and leads to serious economic losses. The interactions between R. solanacearum and host plants have become a model system for the study of plants and pathogens interactions. This paper reviews the advances on the molecular mechanisms between R. solanacearum and hosts interaction including the formation of plant innate immunity, the suppression of plant innate immunity by this pathogen and the activation of effector-triggered immunity. Furthermore, we made a prospect on how to utilize the interaction mechanism between R. solanacearum and hosts to control the disease.展开更多
Blast disease,caused by the hemibiotrophic ascomycete fungus,Magnaporthe oryzae,is a significant threat to sustainable rice production worldwide.Studies have shown that the blast fungus secretes vast arrays of functio...Blast disease,caused by the hemibiotrophic ascomycete fungus,Magnaporthe oryzae,is a significant threat to sustainable rice production worldwide.Studies have shown that the blast fungus secretes vast arrays of functionally diverse proteins into the host cell for a successful disease progression.However,the final destinations of these effector proteins inside the host cell and their role in advancing fungal pathogenesis remain a mystery.Here,we reported that a putative mitochondrial targeting non-classically secreted protein(MoMtp)positively regulates conidiogenesis and appressorium maturation in M.oryzae.Moreover,MoM TP gene deletion mutant strains triggered a hypersensitive response when inoculated on rice leaves displaying that MoMtp is essential for the virulence of M.oryzae.In addition,cell wall and oxidative stress results indicated that MoMtp is likely involved in the maintenance of the structural integrity of the fungus cell.Our study also demonstrates an upregulation in the expression pattern of the MoMTP gene at all stages of infection,indicating its possible regulatory role in host invasion and the infectious development of M.oryzae.Furthermore,Agrobacterium infiltration and sheath inoculation confirmed that MoMtpGFP protein is predominantly localized in the host mitochondria of tobacco leaf and rice cells.Taken together,we conclude that MoMtp protein likely promotes the normal conidiation and pathogenesis of M.oryzae and might have a role in disturbing the proper functioning of the host mitochondria during pathogen invasion.展开更多
Nematode identification serves as an important param-eter to study their behaviour,importance and pathogenic-ity.Application of classical morphometric based identifica-tion methods prove to be lacking due to insuffici...Nematode identification serves as an important param-eter to study their behaviour,importance and pathogenic-ity.Application of classical morphometric based identifica-tion methods prove to be lacking due to insufficient knowledge on morphological variations among closely related taxa.Molecular approaches such as DNA and protein-based information,microarray,probing,sequence-based methods and others have been used to supplement morphology-based methods for nematode identification.Ascarosides and certain protein-based nematode-associated molecular patterns(NAMPs),can be perceived by the host plants,and can initiate a signalling cascade.This review primarily emphasizes on an updated account of different classical and modern tools used for the identification of nematodes.Besides we also summa-rize the mechanism of some important signalling pathways which are involved in the different plant nematode interactions.Nematodes constitute most diverse and least studied group of soil inhabiting invertebrates.They are ecologically and physiologically important,however,wide range of nematodes show harmful impact on the individuals that live within their vicinity.Plant parasitic nematodes(PPNs)are transparent,pseudocoelomate,free living or parasitic microorganisms.PPNs lack morphometric identification methods due to insufficient knowl-edge on morphological variations among closely related taxa.As such,molecular approaches such as DNA and protein-based information,microarray,probing,sequence-based methods and others have been used to supplement morphology-based methods for their identification.To invade the defense response of different plant species,parasitic nematodes have evolved different molecular strategies.Ascarosides and certain protein-based nematode-associated molecular patterns(NAMPs),can be perceived by the host plants,and can initiate a signaling cascade.To overcome the host confrontation and develop certain nematode feeding sites,some members can inject effectors into the cells of susceptible hosts to reprogram the basal resistance signaling.This review primarily emphasizes on an updated account of different classical and modem tools used for the identification of PPNs.Besides we also summarize the mechanism of some important signaling pathways which are involved in the different plant nematode interactions.展开更多
Research on the stress gradient hypothesis recognizes that positive(i.e. facilitative) and negative(i.e. competitive) plant interactions change in intensity and effect relative to abiotic stress experienced on a gradi...Research on the stress gradient hypothesis recognizes that positive(i.e. facilitative) and negative(i.e. competitive) plant interactions change in intensity and effect relative to abiotic stress experienced on a gradient. Motivated by observations of alpine treeline ecotones, we suggest that this switch in interaction could operate along a gradient of relative size of individual plants. We propose that as neighbors increase in size relative to a focal plant they improve the environment for that plant up to a critical point. After this critical point is surpassed, however, increasing relative size of neighbors will degrade the environment such that the net interaction intensity becomes negative. We developed a conceptual(not site or species specific) individual based model to simulate a single species with recruitment, growth, and mortality dependent on the environment mediated by the relative size of neighbors. Growth and size form a feedback. Simulation results show that the size gradient model produces metrics similar to that of a stress gradient model. Visualizations reveal that the size gradient model produces spatial patterns that are similar to the complex ones observed at alpine treelines. Size-mediated interaction could be a mechanism of the stress gradient hypothesis or it could operate independent of abiotic stress.展开更多
Plants are colonized by various microorganisms in natural environments.While many studies have demonstrated key roles of the rhizosphere microbiota in regulating biological processes such as nutrient acquisition and r...Plants are colonized by various microorganisms in natural environments.While many studies have demonstrated key roles of the rhizosphere microbiota in regulating biological processes such as nutrient acquisition and resistance against abiotic and biotic challenges,less is known about the role of the phyllosphere microbiota and how it is established and maintained.This review provides an update on current understanding of phyllosphere community assembly and the mechanisms by which plants and microbes establish the phyllosphere microbiota for plant health.展开更多
Plant resistance against insects mainly depends on nutrient restriction and toxic metabolites, but the relative importance of nutrition and toxins remains elusive. We examined performance, nutrition ingestion, and tra...Plant resistance against insects mainly depends on nutrient restriction and toxic metabolites, but the relative importance of nutrition and toxins remains elusive. We examined performance, nutrition ingestion, and transcriptome response of the English grain aphid, Sitobion avenae, feeding on resistant Xiaoyan 22(XY22) and susceptible Xinong 979(XN979) wheat cultivars. Aphids had lower body weight and fecundity when feeding on XY22 than on XN979, although the phloem sap of XY22 had a higher nutritive quality(in terms of amino acid:sucrose ratio). Aphids feeding on XY22 also had a lower honeydew excretion rate than those on XN979, suggesting that aphids ingested less phloem sap from XY22. The transcriptome data showed 600 differentially expressed genes(DEGs), and 11 of the top 20 KEGG pathways significantly enriched in DEGs were involved in nutrient metabolism. We found 81 DEGs associated with the metabolism of sugars, lipids, and amino acids, 59 of which were significantly downregulated in aphids feeding on XY22. In contrast, there were 18 DEGs related to detoxifying metabolism, namely eight UDP-glucuronosyltransferases, six cytochromes P450 monooxygenases, one glutathione S-transferase, two ATP-binding cassette transporters, and one major facilitator superfamily transporter;12 of these were upregulated in the aphids feeding on XY22. Our results indicated that both the quantity and quality of phloem nutrition available to aphids are critical for the growth and development of aphids, and the higher resistance of XY22 is mainly due to the reduction in phloem sap ingested by aphids, rather than toxic metabolites.展开更多
Carbon catabolite repression(CCR)plays a key role in many physiological and adaptive responses in a broad range of microorganisms that are commonly associated with eukaryotic hosts.When a mixture of different carbon s...Carbon catabolite repression(CCR)plays a key role in many physiological and adaptive responses in a broad range of microorganisms that are commonly associated with eukaryotic hosts.When a mixture of different carbon sources is available,CCR,a global regulatory mechanism,inhibits the expression and activity of cellular processes associated with utilization of secondary carbon sources in the presence of the preferred carbon source.CCR is known to be executed by completely different mechanisms in different bacteria,yeast,and fungi.In addition to regulating catabolic genes,CCR also appears to play a key role in the expression of genes involved in plant–microbe interactions.Here,we present a detailed overview of CCR mechanisms in various bacteria.We highlight the role of CCR in beneficial as well as deleterious plant–microbe interactions based on the available literature.In addition,we explore the global distribution of known regulatory mechanisms within bacterial genomes retrieved from public repositories and within metatranscriptomes obtained from different plant rhizospheres.By integrating the available literature and performing targeted meta-analyses,we argue that CCR-regulated substrate use preferences of microorganisms should be considered an important trait involved in prevailing plant–microbe interactions.展开更多
Drug-drug interactions have become a serious problem in the clinic, since plant-based medicines are extensively used. The present study investigated the effects of Ziziphusjujuba fruit （Z J） extract on the pharmacok...Drug-drug interactions have become a serious problem in the clinic, since plant-based medicines are extensively used. The present study investigated the effects of Ziziphusjujuba fruit （Z J） extract on the pharmacokinetics of phenacetin, a typical substrate of a cytochrome P450 enzyme CYP 1A2, in rats. The rats were pretreated with the water extract （1.0 g·kg-l） or the ethanolic extract （3.6 g·kg-1） of ZJ for 10 days, and the pharmacokinetics of phenacetin was investigated after intravenous administration. In an in vitro assay, acetaminophen formation in the hepatic microsomes of ZJ-treated rats was investigated to assess CYP1A2 activity. Our results demonstrated that the treatment with the water and ethanolic extracts of ZJ decreased the plasma concentration of phenacetin and increased the plasma concentration of acetaminophen, resulting in a 43.2% and 15.5% reduction in the AUC0-120 of phenacetin, respectively, and a 53.2% and 64.9% increase in the AUC0-120 of acetaminophen, respectively after intravenous administration. The water or ethanolic extract of ZJ significantly increased the clearance of phenacetin and acetaminophen formation in hepatic microsomes. In conclusion, ZJ extracts displayed effects on the pharmacokinetics of phenacetin and increased the CYP1A2 activity in rats. Therefore, precaution on drug-drug interactions should be taken when ZJ is co-administered with drugs metabolized by CYP1A2, which may result in decreased concentrations of these drugs.展开更多
Mammalian sex hormones are spread in the environment from natural and anthropogenic sources. In the present study, the effect of estradiol on Arabidopsis thaliana growth primary metabolism, phenylpropanoid and flavono...Mammalian sex hormones are spread in the environment from natural and anthropogenic sources. In the present study, the effect of estradiol on Arabidopsis thaliana growth primary metabolism, phenylpropanoid and flavonoid pathways and pathogen resistance were investigated. Treatments of Arabidopsis plants with 10 and 100 nM 17β-estradiol resulted in enhanced root growth and shoot biomass. In addition, treated plants had an increased rate of photosynthesis with a concomitant increase in carbohydrate and protein accumulation. Plants exposed to higher concentrations of 17β-estradiol (10 μM) had significantly lower root growth, biomass, photosynthesis rate, primary metabolite and phenylpropanoid and flavonoid contents indicating a toxic effect of estradiol. Treatments with increasing estradiol concentrations (10 nM, 100 nM and 10 μM) resulted in the downregulation of phenylpropanoid-flavonoid pathway genes (PAL1, PAL4, CHI and ANS) and subsequent decreased accumulation of phenolics, flavonoids and anthocyanins. Estradiol-treated plants were inoculated with Pseudomonas syringae pv. Tomato DC3000 and basal resistance was determined. Estradiol treatments rendered plants susceptible to the pathogen, thus compromising the plant defense mechanisms. These results indicate that at low concentrations, estradiol functions as a biostimulant of growth, yield and primary metabolism of Arabidopsis. However, estradiol functions as a potential transcriptional regulator of the phenylpropanoid pathway genes in Arabidopsis, having a negative effect on the phenylpropanoid and flavonoid biosynthetic pathways.展开更多
基金received financial support from the Shenzhen Science and Technology Program,China(KQTD20180411143628272)the special funds for Science Technology Innovation and Industrial Development of Shenzhen Dapeng New District,China(PT202101-02)。
文摘The oral secretions of insect herbivores are complex mixtures of organic and inorganic solutes and enzymes that are deposited onto plant tissues during the feeding process.Some specific components of insect oral secretions have been shown to confer important functions in mediating plant–insect interactions at the molecular level.In this review,we examined the biochemical studies of insect oral secretions to summarize the current knowledge of their compositions.We then moved beyond the functional studies of components of oral secretions,and focused on the literature that pinpointed specific molecular targets of these compounds.Finally,we highlighted the investigations of oral secretion components in the context of insect physiology,which shed light on the potential evolutionary trajectory of these multi-functional molecules.
基金supported by the National Natural Science Foundation of China(Nos.32171533 and 31971444)Anhui Provincial Natural Science Foundation(No.2208085J28)。
文摘Insect herbivory is ubiquitous in various ecosystems,and directly influences the growth and survival of individual plants,especially during their vulnerable early life stages like the seedling phase.This,in turn,exerts a significant influence on forest community diversity and structure,as well as ecosystem function and stability.Notable variation in herbivory has been detected both among and within plant species.For decades,many hypotheses have been proposed to explain such variations,including both biotic and abiotic variables.However,most studies have considered only one or several of these hypotheses by focusing on a few potential variables,and their results were usually inconsistent;thus,the factors driving herbivory remain unclear.In this study,we examined leaf herbivory by insects of woody species seedlings in a subtropical forest in southwestern China over two seasons.In total,24 potential variables that represented abiotic resource availability,characters of individual seedlings,conspecific and heterospecific species,and the whole seedling community were selected to test several commonly discussed alternative herbivory hypotheses.Overall,our findings showed that the plant apparency hypothesis was more supported than the other hypotheses in explaining insect seedling herbivory.Our results further indicated that the mechanisms and causes of insect herbivory are complex,multifactorial,species-specific and vary with seasons,indicating that there may be no uniform rules in explaining herbivory for all seedlings.Consequently,such complexity may play an important role in promoting species coexistence and biodiversity maintenance in seedling communities,which may further translate into the following generation of saplings or even adult communities.Changes in the community of insect herbivores and/or variables influencing insect herbivory,may disrupt stability of the original seedling community,thus affecting the regeneration and development of the entire forest community.Therefore,we suggest that issues related to insect herbivory should be considered when developing forest management and conservation.
基金supported by the National Natural Science Foundation of China (31970274 (J.W.), 32170272 (X.W.), 32100251 (J.Z.), 32000179 (Y.X.))the Special Research Assistant of Chinese Academy of Sciences (J.Z. and Y.X.), China Postdoctoral Science Foundation (2022M713224 (J.Z.))+6 种基金the Strategic Priority Research Program of Chinese Academy of Sciences (XDPB16 (J.W.))the Yunnan Innovation Team Project (202105AE160013 (J.W.))CAS “Light of West China” Program (G.S.)Yunnan Revitalization Talent Support Program “Young Talents” Project (XDYC-QNRC-2022-0301 (J.Z.), XDYC-QNRC-2022-0001 (G.S.))the General and Key Project of the Applied Basic Research Program of Yunnan (202001AS070021(J.W.))Yunnan Fundamental Research Projects-General Project (202101AT070457 (S.L.))Yunnan Fundamental Research Projects-Youth Talent Project (202101AU070021(S.L.))
文摘Parasitic plants and their hosts communicate through haustorial connections.Nutrient deficiency is a common stress for plants,yet little is known about whether and how host plants and parasites communicate during adaptation to such nutrient stresses.In this study,we used transcriptomics and proteomics to analyze how soybean(Glycine max)and its parasitizing dodder(Cuscuta australis)respond to nitrate and phosphate deficiency(-N and-P).After-N and-P treatment,the soybean and dodder plants exhibited substantial changes of transcriptome and proteome,although soybean plants showed very few transcriptional responses to-P and dodder did not show any transcriptional changes to either-N or-P.Importantly,large-scale interplant transport of mRNAs and proteins was detected.Although the mobile mRNAs only comprised at most 0.2%of the transcriptomes,the foreign mobile proteins could reach 6.8%of the total proteins,suggesting that proteins may be the major forms of interplant communications.Furthermore,the interplant mobility of macromolecules was specifically affected by the nutrient regimes and the transport of these macromolecules was very likely independently regulated.This study provides new insight into the communication between host plants and parasites under stress conditions.
基金This work was supported by the King Mongkut’s University of Technology Thonburi through the Post-doctoral Fellowship and the KMUTT 55th Anniversary Commemorative Fund.We thank Ms.Suthathip Kittisenachai,Mr.Yodying Yingchutrakul,and Mr.Sucheewin Krobthong of the National Center for Genetic Engineering and Biotechnology(BIOTEC)for their valuable help in the Proteomics Research Laboratory.
文摘Phytoremediation is a sustainable remedial approach for removing benzene from environment.Plant associated bacteria could ameliorate the phytotoxic effects of benzene on plant,although the specificity of these interactions is unclear.Here,we used proteomics approach to gain a better understanding of the mechanisms involved in plant-bacteria interactions.Plant associated bacteria was isolated and subsequently inoculated into the sterilized Helianthus annuus,and the uptake rates of benzene by these inoculated plants were evaluated.At the end of the experiment,leaves and roots proteins were analyzed.The results showed inoculated H.annuus with strain EnL3 removed more benzene than other treatments after 96 h.EnL3 was identified as Enterobacter sp.according to 16S rDNA analysis.Based on the comparison of proteins,62 proteins were significantly up or down regulated in inoculated leaves,while 35 proteins were significantly up or down regulated in inoculated roots.Furthermore,there were 4 and 3 identified proteins presented only in inoculated H.annuus leaves and roots,respectively.These proteins involved in several functions including transcription and translation,photosynthesis,and stress response.The network among anti-oxidant defense system,protein synthesis,and photosynthetic electron transfer are involved in collaboratively activate the benzene uptake and stress tolerance in plant.
文摘The ＂XIV International Symposium on Iron Nutrition and Interactions in Plants＂ （14th ISINIP） will be held in Beijing, China, on 11-15 October 2008. It will be held together with the Annual Meeting of HarvestPlus-China. The joint symposium will provide opportunities to scientists from soil sciences, plant nutrition, plant breeding, animal and human nutrition around the world to communicate their new results and experiences in studying iron nutrition of plants, animal and human for a better understanding of the mechanisms of iron from soils, over plants to animals and human beings. The scientific topics of the symposium are as follows：
文摘Objective:To document ethnobotanical informations of useful woody plant species in the region of Kotli,Azad Kashmir.Methods:An ethnobotanical survey was conducted in Kotli.Data were collected by interview and semi structured questionnaire from selected local informants and traditional practitioners as well as by field assessment.Results:The present study documented the etnobotanical uses of 33 woody plant species.Most of the species have been used for dual purpose.Only 5 species are used for one purpose.Study revealed all species have medicinal value,among which 21 were used as fuel wood species,16 as fodder species,4 as timber wood species,12 as edible fruit species,6 as fence or hedge plant,7 as ornamental species and 12 species had other uses.Conclusions:Medicinal plants are still widely used for health care by locals of Kotli.Some species of woodlands seem to be vulnerable to overcollection and deforestation.As the young generation is diverted toward allelopathic medicines,ethnobotanical knowledges of important medicinal plants are restricted to the old people only.It is suggested to close the forest of district Kotli for next two to three decades for the conservation of plant biodiversity.
基金facilitated by funding provided by cooperative agreements between the National Park Service (Lake Mead National Recreation Area,in particular Alice NEWTON) and the University of Nevada Las Vegas (UNLV)
文摘Exotic plant invasion is a growing concern in the conservation and management of indigenous arid land ecosystems. By creating areas of ameliorated microclimates and fertile soil below their canopies, perennial plants might influence exotic annual plant invasions. We conducted a quantitative literature review of studies that compared exotic annual plant abundance among native perennial plant species and interspace （open areas） microsites in North America＇s Mojave Desert, where exotic plant invasion has corresponded with increasing extent of wildfire and broad-scale ecosystem transformation. Ten studies compared exotic annual plant abundance between inter- spaces and below a total of 36 native perennial species. These studies revealed that： （1） With few exceptions, most native perennial species supported a greater abundance of exotic annuals than interspaces, indicating overall facilitation of exotic species by native perennials. （2） Exotic species abundance varied by orders of magnitude among native perennial species, with some perennial species harboring amounts of exotics similar to interspaces. （3） Distributions of dominant exotic species varied, where Bromus rubens displayed a greater affinity for below-perennial microsites than did Schismus spp. and Erodium cicutarium that often were most abundant in interspaces. Results suggest that the degree of facilitation of exotic plants warrants consideration when selecting native perennial species for revegetation and restoration projects.
基金This study was supported by the National Natural Science Foundation of China(No.31971453)Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)and Postgraduate Research&Practice Innovation Program of Jiangsu Province.
文摘Nitrogen is an essential component in forest ecosystem nutrient cycling.Nitrogen fractions,such as dissolved nitrogen,ammonium,nitrate,and microbial biomass nitrogen,are sensitive indicators of soil nitrogen pools which affect soil fertility and nutrient cycling.However,the responses of nitrogen fractions in forest soils to organic mulching are less well understood.The rhizosphere is an important micro-region that must be considered to better understand element cycling between plants and the soil.A field investigation was carried out on the effect of mulching soil in a 15-year-old Ligustrum lucidum urban plantation.Changes in total nitrogen and nitrogen fractions in rhizosphere and bulk soil in the topsoil(upper 20 cm)and in the subsoil(20-40 cm)were evaluated following different levels of mulching,in addition to nitrogen contents in fine roots,leaves,and organic mulch.The relationships between nitrogen fractions and other measured variables were analysed.Organic mulching had no significant effect on most nitrogen fractions except for the rhizosphere microbial biomass nitrogen(MBN),and the thinnest(5 cm)mulching layer showed greater effects than other treatments.Rhizosphere MBN was more sensitive to mulching compared to bulk soil,and was more affected by soil environmental changes.Season and soil depth had more pronounced effects on nitrogen fractions than mulching.Total nitrogen and dissolved nitrogen were correlated to soil phosphorus,whereas other nitrogen fractions were strongly affected by soil physical properties(temperature,water content,bulk density).Mulching also decreased leaf nitrogen content,which was more related to soil nitrogen fractions(except for MBN)than nitrogen contents in either fine roots or organic mulch.Frequent applications of small quantities of organic mulch contribute to nitrogen transformation and utilization in urban forests.
基金supported by the National Key Research and Development Program of China(2023YFF0805602)the National Natural Science Foundation of China(U21A20186,32171579,32371592 and 32471674)the Natural Science Foundation of Gansu Province,China(23JRRA1029 and 23JRRA1034)。
文摘Plant roots interact with diverse fungi that are essential for maintaining the productivity and sustainability of pasture ecosystems,but how these root-associated fungi(RAF)differ between forage species and how they respond to nutrient enrichment and fungicide application are not well understood.Here,we constructed an 11-year experiment involving fungicide application(with or without)nested within four levels of experimental nitrogen(N)addition treatments in an alpine pasture,and the RAF communities,root traits,tissue nutrients,and shoot biomass of two dominant forage species(Carex capillifolia and Elymus nutans)were analyzed.The RAF community composition showed striking differences between the plant species and was strongly affected by both N addition level and fungicide applications.Fungicide,but not N application,dramatically reduced the RAF richness of all functional guilds in both plant species,and fungicide also simplified the co-occurrence network of the RAF for C.capillifolia.The RAF community correlated strongly with root traits,whereas their relationships became weakened or even vanished at the level of the individual plant species.The importance of RAF to plant nutrients and productivity varied between plant species,with significant contributions in C.capillifolia but not in E.nutans.This is the first report elucidating the long-term effect of fungicides on RAF in alpine pastures,and our findings emphasize the host-specific responses of RAF community structure and function to anthropogenic disturbances.
文摘Sound contains mechanical signals that can promote physiological and biochemical changes in plants.Insects produce different sounds in the environment,which may be relevant to plant behavior.Thus,we evaluated whether signaling cascades are regulated differently by ecological sounds and whether they trigger molecular responses following those produced by herbivorous insects.Soybean plants were treated with two different sounds:chewing herbivore and forest ambient.The responses were markedly distinct,indicating that sound signals may also trigger specific cascades.Enzymes involved in oxidative metabolism were responsive to both sounds,while salicylic acid(SA)was responsive only to the chewing sound.In contrast,lipoxygenase(LOX)activity and jasmonic acid(JA)did not change.Soybean Kunitz trypsin inhibitor gene(SKTI)and Bowman-Birk(BBI)genes,encoding for protease inhibitors,were induced by chewing sound.Chewing sound-induced high expression of the pathogenesis-related protein(PR1)gene,confirming the activation of SA-dependent cascades.In contrast,the sound treatments promoted modifications in different branches of the phenylpropanoid pathway,highlighting a tendency for increased flavonols for plants under chewing sounds.Accordingly,chewing sounds induced pathogenesis-related protein(PR10/Bet v-1)and gmFLS1 flavonol synthase(FLS1)genes involved in flavonoid biosynthesis and flavonols.Finally,our results propose that plants may recognize herbivores by their chewing sound and that different ecological sounds can trigger distinct signaling cascades.
文摘Garlic is a most important medicinal herb belonging to the family Liliaceae. Both its leaves and bulb are edible. The current study was based on evaluating the growth promoting potential of plant growth promoting rhizobacteria (PGPR) on garlic (Allium sativum L.) growth and biochemical contents. Garlic cloves were inoculated with 3 kinds of PGPRs, Pseudomonas putida (KX574857), Pseudomonas stutzeri (Kx574858) and Bacillus cereus (ATCC14579) at 10<sup>8</sup> cells/mL prior to sowing. Under natural conditions, plants were grown in the net house. The PGPR significantly enhanced % germination, leaf and root growth and their biomass also increased the diameter of bulb and fresh and dry weight. The flavonoids, phenolics, chlorophyll, protein and sugar content were also significantly increased due to PGPR inoculation. The Pseudomonas stutzeri was found most effective for producing longer leaves with moderate sugar, high flavonoids (129%) and phenolics (263%) in bulb over control (Tap). The Pseudomonas putida exhibited a maximum increase in bulb diameter and bulb biomass with maximum phenolics and flavonoid contents.
基金Supported by Fundamental Research Funds for the Central Universities(110201202002)
文摘Ralstonia solanacearum is an important model phytopathogenic bacterium that causes bacterial wilt disease on many plant species and leads to serious economic losses. The interactions between R. solanacearum and host plants have become a model system for the study of plants and pathogens interactions. This paper reviews the advances on the molecular mechanisms between R. solanacearum and hosts interaction including the formation of plant innate immunity, the suppression of plant innate immunity by this pathogen and the activation of effector-triggered immunity. Furthermore, we made a prospect on how to utilize the interaction mechanism between R. solanacearum and hosts to control the disease.
基金funded by the National Natural Science Foundation of China(32172364 to Shihong Zhang and 32272513 to Zonghua Wang)Fujian Agriculture and Forestry University scholarship,China for Wajjiha Batool。
文摘Blast disease,caused by the hemibiotrophic ascomycete fungus,Magnaporthe oryzae,is a significant threat to sustainable rice production worldwide.Studies have shown that the blast fungus secretes vast arrays of functionally diverse proteins into the host cell for a successful disease progression.However,the final destinations of these effector proteins inside the host cell and their role in advancing fungal pathogenesis remain a mystery.Here,we reported that a putative mitochondrial targeting non-classically secreted protein(MoMtp)positively regulates conidiogenesis and appressorium maturation in M.oryzae.Moreover,MoM TP gene deletion mutant strains triggered a hypersensitive response when inoculated on rice leaves displaying that MoMtp is essential for the virulence of M.oryzae.In addition,cell wall and oxidative stress results indicated that MoMtp is likely involved in the maintenance of the structural integrity of the fungus cell.Our study also demonstrates an upregulation in the expression pattern of the MoMTP gene at all stages of infection,indicating its possible regulatory role in host invasion and the infectious development of M.oryzae.Furthermore,Agrobacterium infiltration and sheath inoculation confirmed that MoMtpGFP protein is predominantly localized in the host mitochondria of tobacco leaf and rice cells.Taken together,we conclude that MoMtp protein likely promotes the normal conidiation and pathogenesis of M.oryzae and might have a role in disturbing the proper functioning of the host mitochondria during pathogen invasion.
文摘Nematode identification serves as an important param-eter to study their behaviour,importance and pathogenic-ity.Application of classical morphometric based identifica-tion methods prove to be lacking due to insufficient knowledge on morphological variations among closely related taxa.Molecular approaches such as DNA and protein-based information,microarray,probing,sequence-based methods and others have been used to supplement morphology-based methods for nematode identification.Ascarosides and certain protein-based nematode-associated molecular patterns(NAMPs),can be perceived by the host plants,and can initiate a signalling cascade.This review primarily emphasizes on an updated account of different classical and modern tools used for the identification of nematodes.Besides we also summa-rize the mechanism of some important signalling pathways which are involved in the different plant nematode interactions.Nematodes constitute most diverse and least studied group of soil inhabiting invertebrates.They are ecologically and physiologically important,however,wide range of nematodes show harmful impact on the individuals that live within their vicinity.Plant parasitic nematodes(PPNs)are transparent,pseudocoelomate,free living or parasitic microorganisms.PPNs lack morphometric identification methods due to insufficient knowl-edge on morphological variations among closely related taxa.As such,molecular approaches such as DNA and protein-based information,microarray,probing,sequence-based methods and others have been used to supplement morphology-based methods for their identification.To invade the defense response of different plant species,parasitic nematodes have evolved different molecular strategies.Ascarosides and certain protein-based nematode-associated molecular patterns(NAMPs),can be perceived by the host plants,and can initiate a signaling cascade.To overcome the host confrontation and develop certain nematode feeding sites,some members can inject effectors into the cells of susceptible hosts to reprogram the basal resistance signaling.This review primarily emphasizes on an updated account of different classical and modem tools used for the identification of PPNs.Besides we also summarize the mechanism of some important signaling pathways which are involved in the different plant nematode interactions.
基金based upon work while an author served at the National Science Foundation(USA)
文摘Research on the stress gradient hypothesis recognizes that positive(i.e. facilitative) and negative(i.e. competitive) plant interactions change in intensity and effect relative to abiotic stress experienced on a gradient. Motivated by observations of alpine treeline ecotones, we suggest that this switch in interaction could operate along a gradient of relative size of individual plants. We propose that as neighbors increase in size relative to a focal plant they improve the environment for that plant up to a critical point. After this critical point is surpassed, however, increasing relative size of neighbors will degrade the environment such that the net interaction intensity becomes negative. We developed a conceptual(not site or species specific) individual based model to simulate a single species with recruitment, growth, and mortality dependent on the environment mediated by the relative size of neighbors. Growth and size form a feedback. Simulation results show that the size gradient model produces metrics similar to that of a stress gradient model. Visualizations reveal that the size gradient model produces spatial patterns that are similar to the complex ones observed at alpine treelines. Size-mediated interaction could be a mechanism of the stress gradient hypothesis or it could operate independent of abiotic stress.
基金This work was supported by the Chinese Academy of Sciences,Center for Excellence in Molecular Plant Sciences/Institute of Plant Physiology and Ecology,National Key Laboratory of Molecular Plant Genetics and the Chinese Academy of Sciences Strategic Priority Research Program(type B,project no.XDB27040211).
文摘Plants are colonized by various microorganisms in natural environments.While many studies have demonstrated key roles of the rhizosphere microbiota in regulating biological processes such as nutrient acquisition and resistance against abiotic and biotic challenges,less is known about the role of the phyllosphere microbiota and how it is established and maintained.This review provides an update on current understanding of phyllosphere community assembly and the mechanisms by which plants and microbes establish the phyllosphere microbiota for plant health.
基金supported by the National Natural Science Foundation of China (31272089)。
文摘Plant resistance against insects mainly depends on nutrient restriction and toxic metabolites, but the relative importance of nutrition and toxins remains elusive. We examined performance, nutrition ingestion, and transcriptome response of the English grain aphid, Sitobion avenae, feeding on resistant Xiaoyan 22(XY22) and susceptible Xinong 979(XN979) wheat cultivars. Aphids had lower body weight and fecundity when feeding on XY22 than on XN979, although the phloem sap of XY22 had a higher nutritive quality(in terms of amino acid:sucrose ratio). Aphids feeding on XY22 also had a lower honeydew excretion rate than those on XN979, suggesting that aphids ingested less phloem sap from XY22. The transcriptome data showed 600 differentially expressed genes(DEGs), and 11 of the top 20 KEGG pathways significantly enriched in DEGs were involved in nutrient metabolism. We found 81 DEGs associated with the metabolism of sugars, lipids, and amino acids, 59 of which were significantly downregulated in aphids feeding on XY22. In contrast, there were 18 DEGs related to detoxifying metabolism, namely eight UDP-glucuronosyltransferases, six cytochromes P450 monooxygenases, one glutathione S-transferase, two ATP-binding cassette transporters, and one major facilitator superfamily transporter;12 of these were upregulated in the aphids feeding on XY22. Our results indicated that both the quantity and quality of phloem nutrition available to aphids are critical for the growth and development of aphids, and the higher resistance of XY22 is mainly due to the reduction in phloem sap ingested by aphids, rather than toxic metabolites.
基金This work was supported by the French National Research Agency(ANR-18-CE32-0005,DIORE).
文摘Carbon catabolite repression(CCR)plays a key role in many physiological and adaptive responses in a broad range of microorganisms that are commonly associated with eukaryotic hosts.When a mixture of different carbon sources is available,CCR,a global regulatory mechanism,inhibits the expression and activity of cellular processes associated with utilization of secondary carbon sources in the presence of the preferred carbon source.CCR is known to be executed by completely different mechanisms in different bacteria,yeast,and fungi.In addition to regulating catabolic genes,CCR also appears to play a key role in the expression of genes involved in plant–microbe interactions.Here,we present a detailed overview of CCR mechanisms in various bacteria.We highlight the role of CCR in beneficial as well as deleterious plant–microbe interactions based on the available literature.In addition,we explore the global distribution of known regulatory mechanisms within bacterial genomes retrieved from public repositories and within metatranscriptomes obtained from different plant rhizospheres.By integrating the available literature and performing targeted meta-analyses,we argue that CCR-regulated substrate use preferences of microorganisms should be considered an important trait involved in prevailing plant–microbe interactions.
基金supported by the National Basic Research Program of China(973 Program)(Nos.2011CB505300 and 2011CB505303)Natural Science Foundation of China(No.81303018)+1 种基金Natural Science Foundation for Colleges and Universities in Jiangsu Province(No.13KJB360006)Natural Science Foundation of Nanjing University of Chinese Medicine(No.12XZR17)
文摘Drug-drug interactions have become a serious problem in the clinic, since plant-based medicines are extensively used. The present study investigated the effects of Ziziphusjujuba fruit （Z J） extract on the pharmacokinetics of phenacetin, a typical substrate of a cytochrome P450 enzyme CYP 1A2, in rats. The rats were pretreated with the water extract （1.0 g·kg-l） or the ethanolic extract （3.6 g·kg-1） of ZJ for 10 days, and the pharmacokinetics of phenacetin was investigated after intravenous administration. In an in vitro assay, acetaminophen formation in the hepatic microsomes of ZJ-treated rats was investigated to assess CYP1A2 activity. Our results demonstrated that the treatment with the water and ethanolic extracts of ZJ decreased the plasma concentration of phenacetin and increased the plasma concentration of acetaminophen, resulting in a 43.2% and 15.5% reduction in the AUC0-120 of phenacetin, respectively, and a 53.2% and 64.9% increase in the AUC0-120 of acetaminophen, respectively after intravenous administration. The water or ethanolic extract of ZJ significantly increased the clearance of phenacetin and acetaminophen formation in hepatic microsomes. In conclusion, ZJ extracts displayed effects on the pharmacokinetics of phenacetin and increased the CYP1A2 activity in rats. Therefore, precaution on drug-drug interactions should be taken when ZJ is co-administered with drugs metabolized by CYP1A2, which may result in decreased concentrations of these drugs.
文摘Mammalian sex hormones are spread in the environment from natural and anthropogenic sources. In the present study, the effect of estradiol on Arabidopsis thaliana growth primary metabolism, phenylpropanoid and flavonoid pathways and pathogen resistance were investigated. Treatments of Arabidopsis plants with 10 and 100 nM 17β-estradiol resulted in enhanced root growth and shoot biomass. In addition, treated plants had an increased rate of photosynthesis with a concomitant increase in carbohydrate and protein accumulation. Plants exposed to higher concentrations of 17β-estradiol (10 μM) had significantly lower root growth, biomass, photosynthesis rate, primary metabolite and phenylpropanoid and flavonoid contents indicating a toxic effect of estradiol. Treatments with increasing estradiol concentrations (10 nM, 100 nM and 10 μM) resulted in the downregulation of phenylpropanoid-flavonoid pathway genes (PAL1, PAL4, CHI and ANS) and subsequent decreased accumulation of phenolics, flavonoids and anthocyanins. Estradiol-treated plants were inoculated with Pseudomonas syringae pv. Tomato DC3000 and basal resistance was determined. Estradiol treatments rendered plants susceptible to the pathogen, thus compromising the plant defense mechanisms. These results indicate that at low concentrations, estradiol functions as a biostimulant of growth, yield and primary metabolism of Arabidopsis. However, estradiol functions as a potential transcriptional regulator of the phenylpropanoid pathway genes in Arabidopsis, having a negative effect on the phenylpropanoid and flavonoid biosynthetic pathways.
