Plants have sophisticated defense systems to fend off insect herbivores. How plants defend against herbivores in dicotyledonous plants, such as Arabidopsis and tobacco, have been relatively well studied, yet little is...Plants have sophisticated defense systems to fend off insect herbivores. How plants defend against herbivores in dicotyledonous plants, such as Arabidopsis and tobacco, have been relatively well studied, yet little is known about the defense responses in monocotyledons. Here, we review the current un- derstanding of rice （Oryza sativa） and maize （Zea rnays） defense against insects. In rice and maize, elicitors derived from insect herbivore oral secretions or oviposition fluids activate phytohormone signaling, and transcriptomic changes mediated mainly by transcription factors lead to accumulation of defense-related secondary metabolites. Direct defenses, such as trypsin protein inhibitors in rice and benzoxazinoids in maize, have anti-digestive or toxic effects on insect herbivores. Herbivory-induced plant volatiles, such as terpenes, are indirect defenses, which attract the natural enemies of herbivores. R gene-mediated defenses against herbivores are also discussed.展开更多
mRNAs are transported within a plant through phloem.Aphids are phloem feeders and dodders(Cuscuta spp.)are parasites which establish phloem connections with host plants.When aphids feed on dodders,whether there is tra...mRNAs are transported within a plant through phloem.Aphids are phloem feeders and dodders(Cuscuta spp.)are parasites which establish phloem connections with host plants.When aphids feed on dodders,whether there is trafficking of mRNAs among aphids,dodders,and host plants and if aphid feeding a匚fects the mRNA transfer between dodders and hosts are unclear.We constructed a green peach aphid(GPA,Myzus persicae)-dodder(Cuscuta austra/is)-cucumber(Cucumis sativus)tritrophic system by infesting GPAs on C.australis,which parasitized cucumber hosts.We found that GPA feeding activated defense-related phytohormonal and transcriptomic responses in both C.australis and cucumbers and large numbers of mRNAs were found to be transferred between C.australis and cucumbers and between C.australis and GPAs;importantly,GPA feeding on C.australis greatly altered inter-species mobile mRNA profiles.Furthermore,three cucumber mRNAs and three GPA mRNAs could be respectively detected in GPAs and cucumbers.Moreover,our statistical analysis indicated that mRNAs with high abundances and long transcript lengths are likely to be mobile.This study reveals the existence of inter-species and even inter-kingdom mRNA movement among insects,parasitic plants,and parasite hosts,and suggests complex regulation of mRNA trafficking.展开更多
Hematophagous invertebrates such as mosquitoes,leeches,mites,ticks,lice and bugs cause various problems for humans.Considering reports on insecticide resistance and requirements for improved environmental and toxicolo...Hematophagous invertebrates such as mosquitoes,leeches,mites,ticks,lice and bugs cause various problems for humans.Considering reports on insecticide resistance and requirements for improved environmental and toxicological profiles,there is a continuing need to discover and develop new insecticides and repellents.Ethnobotanical surveys of traditional plant-based repellents provide a direct method of identifying plants for potential use.During five field surveys in Bulang,Jinuo and Lahu villages between August 2018 and July 2019,semi-structured interviews were conducted with 237 informants(151 male,86 female;mean age 63).Frequency of citation,use value,informant consensus factor and Jaccard index were employed to statistically analyze the collected data.A total of 709 use reports relating to 32 plant species and 71 remedies were collected.Similarities and differences between the three groups,as well as the Dai and Hani of Xishuangbanna,who were studied earlier,were shown through network analysis.These five ethnic groups living in the same area have a common understanding of traditional botanical knowledge against hematophagous invertebrates,but each group also possesses unique knowledge.Recording and protecting this traditional knowledge is potentially useful for protecting this cultural diversity and related biodiversity and can also have important practical applications.In this study,traditional knowledge provided us with many new potential plants for follow-up research for the development of new insecticides and repellents,among which Artemisia indica,Nicotiana tabacum and Clausena excavata are the most promising.展开更多
Stress-associated proteins(SAPs)are known as response factors to multiple abiotic and biotic stresses in plants.However,the potential physiological and molecular functions of SAPs remain largely unclear.Castor bean(Ri...Stress-associated proteins(SAPs)are known as response factors to multiple abiotic and biotic stresses in plants.However,the potential physiological and molecular functions of SAPs remain largely unclear.Castor bean(Ricinus communis L.)is one of the most economically valuable non-edible woody oilseed crops,able to be widely cultivated in marginal lands worldwide because of its broad adaptive capacity to soil and climate conditions.Whether SAPs in castor bean plays a key role in adapting diverse soil conditions and stresses remains unknown.In this study,we used the castor bean genome to identify and characterize nine castor bean SAP genes(RcSAP).Structural analysis showed that castor bean SAP gene structures and functional domain types vary greatly,differing in intron number,protein sequence,and functional domain type.Notably,the AN1-C2H2eC2H2 zinc finger domain within RcSAP9 has not been often observed in other plant families.High throughput RNA-seq data showed that castor bean SAP gene profiles varied among different tissues.In addition,castor bean SAP gene expression varied in response to different stresses,including salt,drought,heat,cold and ABA and MeJA,suggesting that the transcriptional regulation of castor bean SAP genes might operate independently of each other,and at least partially independent from ABA and MeJA signal pathways.Cis-element analyses for each castor bean SAP gene showed that no common cis-elements are shared across the nine castor bean SAP genes.Castor bean SAPs were localized to different regions of cells,including the cytoplasm,nucleus,and cytomembrane.This study provides a comprehensive profile of castor bean SAP genes that advances our understanding of their potential physiological and molecular functions in regulating growth and development and their responses to different abiotic stresses.展开更多
Astaxanthin is a value-added ketocarotenoid with great potential in nutraceutical and pharmaceutical industries.Genetic engineering of heterologous hosts for astaxanthin production has attracted great attention.In thi...Astaxanthin is a value-added ketocarotenoid with great potential in nutraceutical and pharmaceutical industries.Genetic engineering of heterologous hosts for astaxanthin production has attracted great attention.In this study,we assessed some key factors,including codon usage of the expressed genes,types of promoters,bacterial strains,and culture media,for engineered Escherichia coli to produce astaxanthin.The effect of codon usage was shown to be related to the types of promoters.E.coli DH5a was superior to other strains for astaxanthin production.Different culture media greatly affected the contents and yields of astaxanthin in engineered E.coli.When the expression cassette containing GadE promoter and its driving genes,HpCHY and CrBKT,was inserted into the plasmid pACCAR16DcrtX and expressed in E.coli DH5a,the engineered strain was able to produce 4.30±0.28 mg/g dry cell weight(DCW)or 24.16±2.03 mg/L of astaxanthin,which was a sevenfold or 40-fold increase over the initial production of 0.62±0.03 mg/g DCW or 0.61±0.05 mg/L.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
Concrete structures are some of the largest constructions in human civilization.Their manufacture releases CO_(2)into atmosphere,which is partially readsorbed by standing structures,and further release occurs when the...Concrete structures are some of the largest constructions in human civilization.Their manufacture releases CO_(2)into atmosphere,which is partially readsorbed by standing structures,and further release occurs when they are demolished.Concrete is chemically similar to basaltic minerals,both adsorb CO_(2)where they are exposed on the earth's surface.Sequestration of CO_(2)is beneficial to reduce atmospheric concentrations,and thus limit future temperature increases.Therefore,multiple options are being examined for CO_(2)sequestration.For the first time,we compare the CO_(2)sequestration capacity of these two materials.We review previous work quantifying CO_(2)sequestration capacity of both materials and for the first time,compare their potential quantitative roles.Costs of that are compiled,to the extent they have been examined.Costly grinding of these materials to small particle sizes accelerates CO_(2)sequestration,and mycorrhizae in agricultural soils might reduce the associated costs.Both these materials can improve nutrient status in agricultural soils,and limit acidification from external nitrogen fertilization.Limitations are discussed in terms of land-use and material availability,and soil pH conditions.We call for further experiments with these materials that compare CO_(2)sequestration and other biogeochemical processes in agricultural systems across climates,carried out especially where such materials are conveniently available.展开更多
Although research on microplastics(MPs)interactions with other soil pollutants is increasingly becoming available,most studies do not consider risks to soil fertility or plant growth.This review aims:1)to summarize th...Although research on microplastics(MPs)interactions with other soil pollutants is increasingly becoming available,most studies do not consider risks to soil fertility or plant growth.This review aims:1)to summarize the results of current studies on interactions between MPs,heavy metals,and organic pollutants;and 2)subsequently evaluate risks to the soil-plant nexus.Available-literature shows that polypropylene,polyethylene and polylactic acid increase cadmium(Cd)bioavailability and subsequently reduce root growth.Such effects are not evident in sandy or clay soils due to the formation of CdCO3 and iron-oxide by altered bacterial communities that stabilize Cd contamination.Chronic instead of short-term exposure to polystyrene in copper(Cu)-polluted soils decreases crop yield.With coexistence of MPs and lead(Pb)in soil,the uptake of Pb in crops increases,causing altered malondialdehyde content and superoxide dismutase and guaiacol peroxidase activities.Moreover,co-toxicity of polystyrene or polytetrafluoroethylene with arsenic(As)decreases root biomass,photosynthesis rate and the chlorophyll-a content.In alkaline soil,polyvinyl-chloride could decrease the bioavailability of MeHg due to changes in the abundance of Proteobacteria,and Firmicutes.We also found strong interactions between MPs and organic pollutants.Polystyrene decreases negative impacts of sulfamethazine on bacterial diversity,and structure in soil.Polyethylene,polyvinyl-chloride and polystyrene have a strong adsorption capacity for 17β-estradiol.This implies that 17β-estradiol toxicity can be reduced by these MPs.At low concentrations,polyethylene,polypropylene,and polystyrene have low affinity to diazepam.In conclusion,serious ecological risks are associated with MPs and other pollutants'interactions to soil-plant system.展开更多
Ca^(2+)signaling plays crucial roles in plant stress responses,including defense against insects.To counteract insect feeding,different parts of a plant deploy systemic signaling to communicate and coordinate defense ...Ca^(2+)signaling plays crucial roles in plant stress responses,including defense against insects.To counteract insect feeding,different parts of a plant deploy systemic signaling to communicate and coordinate defense responses,but little is known about the underlying mechanisms.In this study,micrografting,in vivo imaging of Ca^(2+)and reactive oxygen species(ROS),quantification of jasmonic acid(JA)and defensive metabolites,and bioassay were used to study how Arabidopsis seedlings regulate systemic responses in leaves after hypocotyls are wounded.We show that wounding hypocotyls rapidly activated both Ca^(2+)and ROS signals in leaves.RBOHD,which functions to produce ROS,along with two glutamate receptors GLR3.3 and GLR3.6,but not individually RBOHD or GLR3.3 and GLR3.6,in hypocotyls regulate the dynamics of systemic Ca^(2+)signals in leaves.In line with the systemic Ca^(2+)signals,after wounding hypocotyl,RBOHD,GLR3.3,and GLR3.6 in hypocotyl also cooperatively regulate the transcriptome,hormone jasmonic acid,and defensive secondary metabolites in leaves of Arabidopsis seedlings,thus controlling the systemic resistance to insects.Unlike leaf-to-leaf systemic signaling,this study reveals the unique regulation of wounding-induced hypocotyl-to-leaf systemic signaling and sheds new light on how different plant organs use complex signaling pathways to modulate defense responses.展开更多
The parasitic dodder(Cuscuta,Convolvulaceae)species have wide ranges of hosts.However,some plants,including the cultivated tomato(Solanum lycopersicum),have different degrees of resistance to Cuscuta.The cultivated to...The parasitic dodder(Cuscuta,Convolvulaceae)species have wide ranges of hosts.However,some plants,including the cultivated tomato(Solanum lycopersicum),have different degrees of resistance to Cuscuta.The cultivated tomato plants activate a strong hypersensitive response(HR)where Cuscuta haustoria penetrate stems of cultivated tomato,but the underlying mechanisms by which the cultivated tomato perceives Cuscuta and activates resistance remain unclear.In this study,we show that the phytohormones jasmonic acid(JA)and salicylic acid(SA)in cultivated tomato stems were highly induced by Cuscuta australis parasitization.Genetic analyses and experiments of supplementation of JA or SA indicated that the JA and SA pathway not only are both required for activation of HR against Cuscuta parasitization but also function in non-HR-based resistance.The Cuscuta Receptor 1(CuRe1),which is a leucine-rich repeat receptor-like protein,and suppressor of BAK1-interacting receptor kinase(SOBIR1)and SOBIR1-like,two adaptor kinases,are also important for HR-based and non-HR-based resistance.Importantly,we found that the JA and SA pathway both transcriptionally regulate CuRe1.However,in the cure1 mutants,JA and SA levels were still normally induced by C.australis parasitization.We propose a linear model that an unknown receptor perceives Cuscuta parasitization and thus triggers accumulation of JA and SA,which in turn induce the transcription of CuRe1,and CuRe1 and SOBIR1/SOBIR1-like thereby activate HR-based and non-HR-based resistance to Cuscuta.This study underscores the important roles of hormone signaling and resistance(R)genes in host plant-parasitic plant interactions.展开更多
Malania oleifera(Olacaceae)is a valued tree species,mostly because its seeds have high precious fatty acid content(particularly nervonic acid).However,seedling mortality rates are often high and regeneration of this t...Malania oleifera(Olacaceae)is a valued tree species,mostly because its seeds have high precious fatty acid content(particularly nervonic acid).However,seedling mortality rates are often high and regeneration of this tree has been problematic,which greatly hinders its utilization at a large scale.Cultivation difficulties of some tree species in the family Olacaceae have been attributed to their root hemiparasitic habit.Prompted by field observations and the taxonomic proximity of M.oleifera to root hemiparasites in Olacaceae,we hypothesized that tuberous structures observed on the roots of M.oleifera are parasitic organs known as haustoria.To test this hypothesis,we collected root samples from M.oleifera plants of various ages and growth conditions,investigated the morphological and anatomical features of tuberous structures and their connections to neighboring roots.Our analyses confirmed that M.oleifera are root hemiparasites.To the best of our knowledge,this is the first empirical report on root hemiparasitism in M.oleifera.Because life strategies of root hemiparasitic plants differ greatly from autotrophic plants,the root hemiparasitic habit needs to be taken into account for successful seedling regeneration of M.oleifera.This study establishes the foundation for investigations into a long-neglected but essential aspect in research of these highly valued tree species.展开更多
Fertilization has been shown to have suppressive effects on arbuscular mycorrhizal fungi(AMF) and root hemiparasites separately in numerous investigations, but its effects on AMF in the presence of root hemiparasites ...Fertilization has been shown to have suppressive effects on arbuscular mycorrhizal fungi(AMF) and root hemiparasites separately in numerous investigations, but its effects on AMF in the presence of root hemiparasites remain untested. In view of the contrasting nutritional effects of AMF and root hemiparasites on host plants, we tested the hypothesis that fertilization may not show strong suppressive effects on AMF when a plant community was infested by abundant hemiparasitic plants. Plants and soil samples were collected from experimental field plots in Bayanbulak Grassland, where N and P fertilizers had been applied for three continuous years for control against a spreading root hemiparasite, Pedicularis kansuensis. Shoot and root biomass of each plant functional group were determined. Root AMF colonization levels, soil spore abundance, and extraradical hyphae length density were measured for three soil depths(0 e10 cm, 10 e20 cm, 20 e30 cm). Partial 18 S r RNA gene sequencing was used to detect AMF diversity and community composition. In addition, we analyzed the relationship between relative abundance of different AMF genera and environmental factors using Spearman's correlation method. In contrast to suppressive effects reported by many previous studies, fertilization showed no significant effects on AMF root colonization or AMF species diversity in the soil. Instead, a marked increase in soil spore abundance and extraradical hyphae length density were observed. However, fertilization altered relative abundance and AMF composition in the soil. Our results support the hypothesis that fertilization does not significantly influence the abundance and diversity of AMF in a plant community infested by P. kansuensis.展开更多
Understanding how geographical patterns of plant richness are established is a key scientific question in ecology and biogeography.Climate factors,such as environmental energy,water availability,and rainfall seasonali...Understanding how geographical patterns of plant richness are established is a key scientific question in ecology and biogeography.Climate factors,such as environmental energy,water availability,and rainfall seasonality,have been widely proposed to account for geographical patterns of plant richness at large scales.Using a compiled distribution data set of 3166 native woody dicotyledons across 732 calibration grids at the county level in humid regions of China,we explored the geographical pattern of woody dicotyledon richness and its relationship to climatic variations,especially the Asian monsoonal climate.We found that species richness decreases with increasing latitude.Our study indicates that water availability(particularly mean annual precipitation,MAP)is the major abiotic factor in determining large-scale distribution patterns of species richness,Moreover,the seasonality of rainfall variables under the Asian monsoon climate largely contributes to species richness,because species richness correlates more significantly with precipitation during the three driest consecutive months(P3 DRY)than precipitation during the three wettest consecutive months(P3 WET).Therefore,we conclude that woody dicotyledon richness in humid regions of China is mainly affected by the Asian winter monsoon.展开更多
Haustorium formation is the characteristic feature of all parasitic plants and a vital process for successful parasitism.Previous investigations on haustorium initiation and development are constricted to induced proc...Haustorium formation is the characteristic feature of all parasitic plants and a vital process for successful parasitism.Previous investigations on haustorium initiation and development are constricted to induced processes by host-derived signals or synthetic analogs.Spontaneous haustorium formation in the absence of host signals,a process representing an early stage in the evolution of parasitic plants,remains largely unexplored.Lack of fast and frequent formation of spontaneous haustoria greatly hinders full understanding of haustorium formation in root hemiparasites.In this study,seedlings of Pedicularis kansuensis Maxim.,a facultative root hemiparasitic species in Orobanchaceae observed to produce many spontaneous haustoria,were grown in autoclaved water agar in the absence of any known haustoriuminducing stimulants.We aimed to test the temporal and developmental pattern of spontaneous haustorium formation.Also,effects of sucrose supply and root contact on spontaneous haustorium formation were tested.Spontaneous haustoria were observed starting from six days after germination,much earlier than previously reported root hemiparasites.A majority of the spontaneous haustoria formed on lateral roots.Percentage of seedlings with spontaneous haustoria was 28.8% when grown on water agar plates,with a mean of four haustoria per seedling two weeks after germination.Haustorium formation by seedlings grown in water agar amended with 2% sucrose was more than twice of those without sucrose amendment.Singly grown seedlings were able to develop spontaneous haustoria at similar levels as those grown with another conspecific seedling.In view of the fast and abundant formation of spontaneous haustoria,P.kansuensis may be developed as an excellent experimental system in future investigations for unraveling endogenous regulation of haustorium initiation and development in root hemiparasitic plants.展开更多
The transcription factor WRINKLED1(WRI1),a member of AP2 gene family that contain typical AP2 domains,has been considered as a master regulator regulating oil biosynthesis in oilseeds.However,the regulatory mechanism ...The transcription factor WRINKLED1(WRI1),a member of AP2 gene family that contain typical AP2 domains,has been considered as a master regulator regulating oil biosynthesis in oilseeds.However,the regulatory mechanism of RcWRI1 in regulating oil accumulation during seed development has not been clearly addressed.Castor bean(Ricinus communis)is one of the most important non-edible oil crops and its seed oils are rich in hydroxy fatty acids,widely applied in industry.In this study,based on castor bean reference genome,three RcWRIs genes(RcWRI1,RcWRI2 and RcWRI3)were identified and the expressed association of RcWRI1 with oil accumulation were determined.Heterologous transformation of RcWRI1 significantly increased oil content in tobacco leaf,confirming that RcWRI1 activate lipid biosynthesis pathway.Using DNA Affinity Purification sequencing(DAP-seq)technology,we confirmed RcWRI1 binding with Transcription Start Site of genes and identified 7961 WRI1-binding candidate genes.Functionally,these identified genes were mainly involved in diverse metabolism pathways(including lipid biosynthesis).Three cis-elements AW-box([CnTnG](n)7[CG])and AW-boxes like([GnAnC](n)6[GC]/[GnAnC](n)7[G])bound with RcWRI1 were identified.Co-expression network analysis of RcWRI1 further found that RcWRI1 might be widely involved in biosynthesis of storage materials during seed development.In particular,yeast one hybrid experiments found that both AP2 domains within RcWRI1 were required in binding targeted genes.These results not only provide new evidence to understand the regulatory mechanism of RcWRI1 in regulation of oil accumulation during castor bean seed development,but also give candidate gene resource for subsequent genetic improvement toward increasing oil content in oilseed crops.展开更多
Adenosma buchneroides Bonati,also known as fleagrass,is an important medicinal plant used by the Akha(Hani)people of China for treating inflammation-related skin swelling,acne,and diarrhoea,among other conditions.In t...Adenosma buchneroides Bonati,also known as fleagrass,is an important medicinal plant used by the Akha(Hani)people of China for treating inflammation-related skin swelling,acne,and diarrhoea,among other conditions.In this study,we aimed to evaluate the anti-inflammatory activities and explore the molecular mechanisms of fleagrass on treating skin swelling and acne.The results demonstrated that fleagrass inhibited the enzymatic activities of 5-LOX and COX-2 in vitro,and decreased the release of NO,IL-6,TNF-α,and IL-10 in the LPS-induced RAW264.7 macrophages.The levels of proteins associated with the nuclear factor-kappa B(NF-κB)pathway were examined by western blotting and immunofluorescence,demonstrating that fleagrass downregulated the expression of TLR4,MyD88,NF-κB/p65,and iNOS and blocked the nuclear translocation of NF-κB/p65.Furthermore,fleagrass exhibited acute anti-inflammatory activity in paw oedema models.The results confirm that fleagrass exhibits remarkable anti-inflammatory activity and can be used in alleviating inflammation,suggesting that fleagrass has the potential to be a novel anti-inflammatory agent.展开更多
Carotenoids are important pigments in photosynthetic organisms where they play essential roles in photoreception and photoprotection.Chromochloris zofingiensis is a unicellular green alga that is able to accumulate hi...Carotenoids are important pigments in photosynthetic organisms where they play essential roles in photoreception and photoprotection.Chromochloris zofingiensis is a unicellular green alga that is able to accumulate high amounts of ketocarotenoids including astaxanthin,canthaxanthin and ketolutein when growing heterotrophically or mixotrophically with glucose as a carbon source.Here we elucidate the ketocarotenoid biosynthesis pathway in C.zofingiensis by analyzing five algal mutants.The mutants were shown to have a single nucleotide insertion or substitution in β-carotene ketolase(BKT) gene 1,which resulted in a lack of ketocarotenoid production in Cz-bktl-1,and decreased ketocarote noid co ntent in the other four mutants.These mutants accumulated much higher amounts of non-ketocarotenoids(β-carotene,zeaxanthin and lutein).Interestingly,the Cz-bktl-5 mutant synthesized 2-fold the ketolutein and only 1/30 of the canthaxanthin and astaxanthin as its parent strain,suggesting that the mutated BKT1 exhibits much higher activity in catalyzing lutein to ketolutein but lower activity in ketolating β-carotene and zeaxanthin.Mutant and WT BKT2 gene sequences did not differ.Taken together,we conclude that BKT1 is the key gene involved in ketocarotenoid biosynthesis in C.zofingiensis.Our study provides insight into the biosynthesis of ketocarotenoids in green algae.Furthermore,Cz-bktl mutants may serve as a natural source for the production of zeaxanthin,lutein,and β-carotene.展开更多
Investigation of the relationships of phenotypic and epigenetic variations might he a good way to dissect the genetic or molecular basis of phenotypic variation and plasticity in plants, Castor bean （Ricinus cornraun...Investigation of the relationships of phenotypic and epigenetic variations might he a good way to dissect the genetic or molecular basis of phenotypic variation and plasticity in plants, Castor bean （Ricinus cornraunis L）, an important non-edible oilseed crop, is a mono-species genus plant in the family Euphorbiaceae. Since it displays rich phenotypic variations with low genetic diversity, castor bean is a good model to investigate the molecular basis of phenotypic and epigenetic variations. Cytosine DNA methylation represents a major molecular mechanism of epigenetic occurrence. In this study, epigenetic diversity of sixty landrace accessions collected worldwide was investigated using the methylation- sensitive amplification polymorphism （MSAP） technique, Results showed that the epigenetic diversity （based on the polymorphism of DNA methylated loci） exhibited a medium variation （Ne = 1.395, He = 0.242, I = 0.366） at the population level though the variation was great, ranging from 3,80% to 3431% among accessions. Both population structure analysis and the phylogenetic construction （using the neighbor-joining criteria） revealed that the two main clades were identified, but they did not display a distinct geographic structure, After inspecting the location of polymorphic methylated loci on genome we identified that the polymorphic methylated loci occur widely in nuclear and organelle genomes. This study provides new data to understand phenotypic and epigenetic variations in castor bean,展开更多
Cuscuta species(dodders)are holoparasites that totally rely on host plants to survive.Although various mobile proteins have been identified to travel within a plant,whether and to what extent protein transfer between ...Cuscuta species(dodders)are holoparasites that totally rely on host plants to survive.Although various mobile proteins have been identified to travel within a plant,whether and to what extent protein transfer between Cuscuta and host plants remain unclear.We found that hundreds to more than 1500 proteins were transferred between Cuscuta and the host plants Arabidopsis and soybean,and hundreds of interplant mobile proteins were even detected in the seeds of Cuscuta and the host soybean.Different hosts bridge-connected by dodder were also found to exchange hundreds of proteins.Quantitatively,the mobile proteins represent a few to more than 10%of the proteomes of foreign plants.Using Arabidopsis plants expressing different reporter proteins,we further showed that these reporter proteins could travel between plants and,importantly,retained their activity in the foreign plants.Comparative analysis between the interplant mobile proteins and mRNAs indicated that the majority of mobile proteins were not de novo synthesized from the translocated mRNAs,but bona fide mobile proteins.We propose that large-scale inter-plant protein translocation may play an important role in the interactions between host plants and dodder and even among the dodder bridge-connected hosts.展开更多
Orobanchaceae is the largest family of parasiticplants,containing autotrophic and parasiticplants with all degrees of parasitism.This makes it byfar the best family for studying the origin and evolution of plant paras...Orobanchaceae is the largest family of parasiticplants,containing autotrophic and parasiticplants with all degrees of parasitism.This makes it byfar the best family for studying the origin and evolution of plant parasitism.Here we provide three high-quality genomes of orobanchaceous plants,the autotrophic Lindenbergia luchunensis and the holoparasitic plants Phelipanche aegyptiaca and Orobanche cumana.Phylogenomic analysis of these three genomes together with those previously published and the transcriptomes of other orobanchaceous species createda robust phylogeneticframework forOrobanchaceae.We found that an ancient whole-genome duplication(WGD;about 73.48million years ago),which occurred earlierthan theoriginof Orobanchaceae,mighthave contributed totheemergence of parasitism.However,no WGD events occurred in any lineage of orobanchaceous parasites except for Striga after divergence from their autotrophic common ancestor,suggesting that,in contrast with previous speculations,WGD is not associated with the emergence of holoparasitism.We detected evident convergent gene loss in all parasites within Orobanchaceae and between Orobanchaceae and dodder Cuscuta australis.The gene families in the orobanchaceous parasites showed a clear pattern of recent gains and expansions.The expanded gene families are enriched in functions related to the development of the haustorium,suggesting that recent gene family expansions may have facilitated the adaptation of orobanchaceous parasites to different hosts.This study illustrates a stepwise pattern in the evolution of parasitism in the orobanchaceous parasites and will facilitate future studieson parasitism and the control of parasitic plants in agriculture.展开更多
基金supported by the National Natural Science Foundation of China(Nos.31772179,U1502263,31600213,31470369,and 31770301)
文摘Plants have sophisticated defense systems to fend off insect herbivores. How plants defend against herbivores in dicotyledonous plants, such as Arabidopsis and tobacco, have been relatively well studied, yet little is known about the defense responses in monocotyledons. Here, we review the current un- derstanding of rice （Oryza sativa） and maize （Zea rnays） defense against insects. In rice and maize, elicitors derived from insect herbivore oral secretions or oviposition fluids activate phytohormone signaling, and transcriptomic changes mediated mainly by transcription factors lead to accumulation of defense-related secondary metabolites. Direct defenses, such as trypsin protein inhibitors in rice and benzoxazinoids in maize, have anti-digestive or toxic effects on insect herbivores. Herbivory-induced plant volatiles, such as terpenes, are indirect defenses, which attract the natural enemies of herbivores. R gene-mediated defenses against herbivores are also discussed.
文摘mRNAs are transported within a plant through phloem.Aphids are phloem feeders and dodders(Cuscuta spp.)are parasites which establish phloem connections with host plants.When aphids feed on dodders,whether there is trafficking of mRNAs among aphids,dodders,and host plants and if aphid feeding a匚fects the mRNA transfer between dodders and hosts are unclear.We constructed a green peach aphid(GPA,Myzus persicae)-dodder(Cuscuta austra/is)-cucumber(Cucumis sativus)tritrophic system by infesting GPAs on C.australis,which parasitized cucumber hosts.We found that GPA feeding activated defense-related phytohormonal and transcriptomic responses in both C.australis and cucumbers and large numbers of mRNAs were found to be transferred between C.australis and cucumbers and between C.australis and GPAs;importantly,GPA feeding on C.australis greatly altered inter-species mobile mRNA profiles.Furthermore,three cucumber mRNAs and three GPA mRNAs could be respectively detected in GPAs and cucumbers.Moreover,our statistical analysis indicated that mRNAs with high abundances and long transcript lengths are likely to be mobile.This study reveals the existence of inter-species and even inter-kingdom mRNA movement among insects,parasitic plants,and parasite hosts,and suggests complex regulation of mRNA trafficking.
基金This study was supported by grant from the National Natural Science Foundation of China[31670337]Plant Germplasm Resources Innovation Project of Chinese Academy of Sciences[KFJBRP-007-002].
文摘Hematophagous invertebrates such as mosquitoes,leeches,mites,ticks,lice and bugs cause various problems for humans.Considering reports on insecticide resistance and requirements for improved environmental and toxicological profiles,there is a continuing need to discover and develop new insecticides and repellents.Ethnobotanical surveys of traditional plant-based repellents provide a direct method of identifying plants for potential use.During five field surveys in Bulang,Jinuo and Lahu villages between August 2018 and July 2019,semi-structured interviews were conducted with 237 informants(151 male,86 female;mean age 63).Frequency of citation,use value,informant consensus factor and Jaccard index were employed to statistically analyze the collected data.A total of 709 use reports relating to 32 plant species and 71 remedies were collected.Similarities and differences between the three groups,as well as the Dai and Hani of Xishuangbanna,who were studied earlier,were shown through network analysis.These five ethnic groups living in the same area have a common understanding of traditional botanical knowledge against hematophagous invertebrates,but each group also possesses unique knowledge.Recording and protecting this traditional knowledge is potentially useful for protecting this cultural diversity and related biodiversity and can also have important practical applications.In this study,traditional knowledge provided us with many new potential plants for follow-up research for the development of new insecticides and repellents,among which Artemisia indica,Nicotiana tabacum and Clausena excavata are the most promising.
基金This research was funded by National Natural Science Foundation of China(31661143002,31771839,31701123and 31501034)Yunnan Applied Basic Research Projects(2016FB060 and 2016FB040).
文摘Stress-associated proteins(SAPs)are known as response factors to multiple abiotic and biotic stresses in plants.However,the potential physiological and molecular functions of SAPs remain largely unclear.Castor bean(Ricinus communis L.)is one of the most economically valuable non-edible woody oilseed crops,able to be widely cultivated in marginal lands worldwide because of its broad adaptive capacity to soil and climate conditions.Whether SAPs in castor bean plays a key role in adapting diverse soil conditions and stresses remains unknown.In this study,we used the castor bean genome to identify and characterize nine castor bean SAP genes(RcSAP).Structural analysis showed that castor bean SAP gene structures and functional domain types vary greatly,differing in intron number,protein sequence,and functional domain type.Notably,the AN1-C2H2eC2H2 zinc finger domain within RcSAP9 has not been often observed in other plant families.High throughput RNA-seq data showed that castor bean SAP gene profiles varied among different tissues.In addition,castor bean SAP gene expression varied in response to different stresses,including salt,drought,heat,cold and ABA and MeJA,suggesting that the transcriptional regulation of castor bean SAP genes might operate independently of each other,and at least partially independent from ABA and MeJA signal pathways.Cis-element analyses for each castor bean SAP gene showed that no common cis-elements are shared across the nine castor bean SAP genes.Castor bean SAPs were localized to different regions of cells,including the cytoplasm,nucleus,and cytomembrane.This study provides a comprehensive profile of castor bean SAP genes that advances our understanding of their potential physiological and molecular functions in regulating growth and development and their responses to different abiotic stresses.
基金This study was supported by a research grant from Department of Economic Plants and Biotechnology,Yunnan Key Laboratory for Wild Plant Resources,Kunming Institute of Botany,Chinese Academy of Sciences.
文摘Astaxanthin is a value-added ketocarotenoid with great potential in nutraceutical and pharmaceutical industries.Genetic engineering of heterologous hosts for astaxanthin production has attracted great attention.In this study,we assessed some key factors,including codon usage of the expressed genes,types of promoters,bacterial strains,and culture media,for engineered Escherichia coli to produce astaxanthin.The effect of codon usage was shown to be related to the types of promoters.E.coli DH5a was superior to other strains for astaxanthin production.Different culture media greatly affected the contents and yields of astaxanthin in engineered E.coli.When the expression cassette containing GadE promoter and its driving genes,HpCHY and CrBKT,was inserted into the plasmid pACCAR16DcrtX and expressed in E.coli DH5a,the engineered strain was able to produce 4.30±0.28 mg/g dry cell weight(DCW)or 24.16±2.03 mg/L of astaxanthin,which was a sevenfold or 40-fold increase over the initial production of 0.62±0.03 mg/g DCW or 0.61±0.05 mg/L.
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supported by the National Natural Science Foundation of China(NSFC Grant No.32001296)the Youth Innovation Promotion Association of CAS,China(Grant No.2022396),and Chinese Academy of Sciences President's International Fellowship Initiative.
文摘Concrete structures are some of the largest constructions in human civilization.Their manufacture releases CO_(2)into atmosphere,which is partially readsorbed by standing structures,and further release occurs when they are demolished.Concrete is chemically similar to basaltic minerals,both adsorb CO_(2)where they are exposed on the earth's surface.Sequestration of CO_(2)is beneficial to reduce atmospheric concentrations,and thus limit future temperature increases.Therefore,multiple options are being examined for CO_(2)sequestration.For the first time,we compare the CO_(2)sequestration capacity of these two materials.We review previous work quantifying CO_(2)sequestration capacity of both materials and for the first time,compare their potential quantitative roles.Costs of that are compiled,to the extent they have been examined.Costly grinding of these materials to small particle sizes accelerates CO_(2)sequestration,and mycorrhizae in agricultural soils might reduce the associated costs.Both these materials can improve nutrient status in agricultural soils,and limit acidification from external nitrogen fertilization.Limitations are discussed in terms of land-use and material availability,and soil pH conditions.We call for further experiments with these materials that compare CO_(2)sequestration and other biogeochemical processes in agricultural systems across climates,carried out especially where such materials are conveniently available.
基金gratefully acknowledge funding from the Postdoctoral Directional Training Foundation of Yunnan(Grant No.EO3A581261)CAS-President’s International Fellowship Initiative(2021PB00094)+1 种基金National Natural Science Foundation of China(Grant No.31861143002)Prof.Jianchu Xu acknowledges funding from Yunnan Department of Sciences and Technology of China(Grant Nos 202101AS070045,202205 AM070007,202302AE090023,202303AP140001).
文摘Although research on microplastics(MPs)interactions with other soil pollutants is increasingly becoming available,most studies do not consider risks to soil fertility or plant growth.This review aims:1)to summarize the results of current studies on interactions between MPs,heavy metals,and organic pollutants;and 2)subsequently evaluate risks to the soil-plant nexus.Available-literature shows that polypropylene,polyethylene and polylactic acid increase cadmium(Cd)bioavailability and subsequently reduce root growth.Such effects are not evident in sandy or clay soils due to the formation of CdCO3 and iron-oxide by altered bacterial communities that stabilize Cd contamination.Chronic instead of short-term exposure to polystyrene in copper(Cu)-polluted soils decreases crop yield.With coexistence of MPs and lead(Pb)in soil,the uptake of Pb in crops increases,causing altered malondialdehyde content and superoxide dismutase and guaiacol peroxidase activities.Moreover,co-toxicity of polystyrene or polytetrafluoroethylene with arsenic(As)decreases root biomass,photosynthesis rate and the chlorophyll-a content.In alkaline soil,polyvinyl-chloride could decrease the bioavailability of MeHg due to changes in the abundance of Proteobacteria,and Firmicutes.We also found strong interactions between MPs and organic pollutants.Polystyrene decreases negative impacts of sulfamethazine on bacterial diversity,and structure in soil.Polyethylene,polyvinyl-chloride and polystyrene have a strong adsorption capacity for 17β-estradiol.This implies that 17β-estradiol toxicity can be reduced by these MPs.At low concentrations,polyethylene,polypropylene,and polystyrene have low affinity to diazepam.In conclusion,serious ecological risks are associated with MPs and other pollutants'interactions to soil-plant system.
基金National Natural Science Foundation of China(U23A20199)Yunnan Revitalization Talent Support Program“Yunling Scholar”and Yunnan Fundamental Research Projects(202201AS070056)。
文摘Ca^(2+)signaling plays crucial roles in plant stress responses,including defense against insects.To counteract insect feeding,different parts of a plant deploy systemic signaling to communicate and coordinate defense responses,but little is known about the underlying mechanisms.In this study,micrografting,in vivo imaging of Ca^(2+)and reactive oxygen species(ROS),quantification of jasmonic acid(JA)and defensive metabolites,and bioassay were used to study how Arabidopsis seedlings regulate systemic responses in leaves after hypocotyls are wounded.We show that wounding hypocotyls rapidly activated both Ca^(2+)and ROS signals in leaves.RBOHD,which functions to produce ROS,along with two glutamate receptors GLR3.3 and GLR3.6,but not individually RBOHD or GLR3.3 and GLR3.6,in hypocotyls regulate the dynamics of systemic Ca^(2+)signals in leaves.In line with the systemic Ca^(2+)signals,after wounding hypocotyl,RBOHD,GLR3.3,and GLR3.6 in hypocotyl also cooperatively regulate the transcriptome,hormone jasmonic acid,and defensive secondary metabolites in leaves of Arabidopsis seedlings,thus controlling the systemic resistance to insects.Unlike leaf-to-leaf systemic signaling,this study reveals the unique regulation of wounding-induced hypocotyl-to-leaf systemic signaling and sheds new light on how different plant organs use complex signaling pathways to modulate defense responses.
基金supported by National Natural Science Foundation of China(32270314(GS))the Key Project of Applied Basic Research Program of Yunnan(202201AS070056(JW),202301AS070064(GS))Yunnan Revitalization Talent Support Program“Yunling Scholar”Project(JW),Chinese Academy of Sciences(CAS)Light of West China Program(GS),Yunnan Revitalization Talent Support Program“Young Talents”Project(XDYC-QNRC-2022-0001(GS)).
文摘The parasitic dodder(Cuscuta,Convolvulaceae)species have wide ranges of hosts.However,some plants,including the cultivated tomato(Solanum lycopersicum),have different degrees of resistance to Cuscuta.The cultivated tomato plants activate a strong hypersensitive response(HR)where Cuscuta haustoria penetrate stems of cultivated tomato,but the underlying mechanisms by which the cultivated tomato perceives Cuscuta and activates resistance remain unclear.In this study,we show that the phytohormones jasmonic acid(JA)and salicylic acid(SA)in cultivated tomato stems were highly induced by Cuscuta australis parasitization.Genetic analyses and experiments of supplementation of JA or SA indicated that the JA and SA pathway not only are both required for activation of HR against Cuscuta parasitization but also function in non-HR-based resistance.The Cuscuta Receptor 1(CuRe1),which is a leucine-rich repeat receptor-like protein,and suppressor of BAK1-interacting receptor kinase(SOBIR1)and SOBIR1-like,two adaptor kinases,are also important for HR-based and non-HR-based resistance.Importantly,we found that the JA and SA pathway both transcriptionally regulate CuRe1.However,in the cure1 mutants,JA and SA levels were still normally induced by C.australis parasitization.We propose a linear model that an unknown receptor perceives Cuscuta parasitization and thus triggers accumulation of JA and SA,which in turn induce the transcription of CuRe1,and CuRe1 and SOBIR1/SOBIR1-like thereby activate HR-based and non-HR-based resistance to Cuscuta.This study underscores the important roles of hormone signaling and resistance(R)genes in host plant-parasitic plant interactions.
基金financially supported by funding for Airong Li from Yunnan Ten Thousand Talents Plan Young and Elite Talents Project (YNWR-QNBJ-2018-092)Youth Innovation Promotion Association of Chinese Academy of Sciences (2011276)+2 种基金Young Academic and Technical Leader Raising Foundation of Yunnan Province (2014HB047)funding for Yunju Li from Young Academic and Technical Leader Raising Foundation of Yunnan Province (2019HB060)Yunnan Science and Technology Innovation Team Program (Grant No. 2019HC015)
文摘Malania oleifera(Olacaceae)is a valued tree species,mostly because its seeds have high precious fatty acid content(particularly nervonic acid).However,seedling mortality rates are often high and regeneration of this tree has been problematic,which greatly hinders its utilization at a large scale.Cultivation difficulties of some tree species in the family Olacaceae have been attributed to their root hemiparasitic habit.Prompted by field observations and the taxonomic proximity of M.oleifera to root hemiparasites in Olacaceae,we hypothesized that tuberous structures observed on the roots of M.oleifera are parasitic organs known as haustoria.To test this hypothesis,we collected root samples from M.oleifera plants of various ages and growth conditions,investigated the morphological and anatomical features of tuberous structures and their connections to neighboring roots.Our analyses confirmed that M.oleifera are root hemiparasites.To the best of our knowledge,this is the first empirical report on root hemiparasitism in M.oleifera.Because life strategies of root hemiparasitic plants differ greatly from autotrophic plants,the root hemiparasitic habit needs to be taken into account for successful seedling regeneration of M.oleifera.This study establishes the foundation for investigations into a long-neglected but essential aspect in research of these highly valued tree species.
基金financially supported by the Natural Science Foundation of China (U1303201, No. 31400440 and No. 31370512)China Agriculture Research System (CARS-34)+2 种基金Natural Science Foundation of Yunnan Province (2016FB059)funding for Airong Li from The Youth Innovation Promotion Association of Chinese Academy of Sciencesthe Young Academic and Technical Leader Raising Foundation of Yunnan Province (2014HB047)
文摘Fertilization has been shown to have suppressive effects on arbuscular mycorrhizal fungi(AMF) and root hemiparasites separately in numerous investigations, but its effects on AMF in the presence of root hemiparasites remain untested. In view of the contrasting nutritional effects of AMF and root hemiparasites on host plants, we tested the hypothesis that fertilization may not show strong suppressive effects on AMF when a plant community was infested by abundant hemiparasitic plants. Plants and soil samples were collected from experimental field plots in Bayanbulak Grassland, where N and P fertilizers had been applied for three continuous years for control against a spreading root hemiparasite, Pedicularis kansuensis. Shoot and root biomass of each plant functional group were determined. Root AMF colonization levels, soil spore abundance, and extraradical hyphae length density were measured for three soil depths(0 e10 cm, 10 e20 cm, 20 e30 cm). Partial 18 S r RNA gene sequencing was used to detect AMF diversity and community composition. In addition, we analyzed the relationship between relative abundance of different AMF genera and environmental factors using Spearman's correlation method. In contrast to suppressive effects reported by many previous studies, fertilization showed no significant effects on AMF root colonization or AMF species diversity in the soil. Instead, a marked increase in soil spore abundance and extraradical hyphae length density were observed. However, fertilization altered relative abundance and AMF composition in the soil. Our results support the hypothesis that fertilization does not significantly influence the abundance and diversity of AMF in a plant community infested by P. kansuensis.
基金the National Natural Science Foundation of China(No.U1502231 and 41661134049)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDA19050301)。
文摘Understanding how geographical patterns of plant richness are established is a key scientific question in ecology and biogeography.Climate factors,such as environmental energy,water availability,and rainfall seasonality,have been widely proposed to account for geographical patterns of plant richness at large scales.Using a compiled distribution data set of 3166 native woody dicotyledons across 732 calibration grids at the county level in humid regions of China,we explored the geographical pattern of woody dicotyledon richness and its relationship to climatic variations,especially the Asian monsoonal climate.We found that species richness decreases with increasing latitude.Our study indicates that water availability(particularly mean annual precipitation,MAP)is the major abiotic factor in determining large-scale distribution patterns of species richness,Moreover,the seasonality of rainfall variables under the Asian monsoon climate largely contributes to species richness,because species richness correlates more significantly with precipitation during the three driest consecutive months(P3 DRY)than precipitation during the three wettest consecutive months(P3 WET).Therefore,we conclude that woody dicotyledon richness in humid regions of China is mainly affected by the Asian winter monsoon.
基金financially supported by the Natural Science Foundation of China(31370512,U1303201,and 31400440)Natural Science Foundation of Yunnan Province(2016FB059)+1 种基金funding for Airong Li from The Youth Innovation Promotion Association of Chinese Academy of Sciencesthe Young Academic and Technical Leader Raising Foundation of Yunnan Province(2014HB047)
文摘Haustorium formation is the characteristic feature of all parasitic plants and a vital process for successful parasitism.Previous investigations on haustorium initiation and development are constricted to induced processes by host-derived signals or synthetic analogs.Spontaneous haustorium formation in the absence of host signals,a process representing an early stage in the evolution of parasitic plants,remains largely unexplored.Lack of fast and frequent formation of spontaneous haustoria greatly hinders full understanding of haustorium formation in root hemiparasites.In this study,seedlings of Pedicularis kansuensis Maxim.,a facultative root hemiparasitic species in Orobanchaceae observed to produce many spontaneous haustoria,were grown in autoclaved water agar in the absence of any known haustoriuminducing stimulants.We aimed to test the temporal and developmental pattern of spontaneous haustorium formation.Also,effects of sucrose supply and root contact on spontaneous haustorium formation were tested.Spontaneous haustoria were observed starting from six days after germination,much earlier than previously reported root hemiparasites.A majority of the spontaneous haustoria formed on lateral roots.Percentage of seedlings with spontaneous haustoria was 28.8% when grown on water agar plates,with a mean of four haustoria per seedling two weeks after germination.Haustorium formation by seedlings grown in water agar amended with 2% sucrose was more than twice of those without sucrose amendment.Singly grown seedlings were able to develop spontaneous haustoria at similar levels as those grown with another conspecific seedling.In view of the fast and abundant formation of spontaneous haustoria,P.kansuensis may be developed as an excellent experimental system in future investigations for unraveling endogenous regulation of haustorium initiation and development in root hemiparasitic plants.
基金This work was supported by National Natural Science Foundation of China(grant number 31701465)。
文摘The transcription factor WRINKLED1(WRI1),a member of AP2 gene family that contain typical AP2 domains,has been considered as a master regulator regulating oil biosynthesis in oilseeds.However,the regulatory mechanism of RcWRI1 in regulating oil accumulation during seed development has not been clearly addressed.Castor bean(Ricinus communis)is one of the most important non-edible oil crops and its seed oils are rich in hydroxy fatty acids,widely applied in industry.In this study,based on castor bean reference genome,three RcWRIs genes(RcWRI1,RcWRI2 and RcWRI3)were identified and the expressed association of RcWRI1 with oil accumulation were determined.Heterologous transformation of RcWRI1 significantly increased oil content in tobacco leaf,confirming that RcWRI1 activate lipid biosynthesis pathway.Using DNA Affinity Purification sequencing(DAP-seq)technology,we confirmed RcWRI1 binding with Transcription Start Site of genes and identified 7961 WRI1-binding candidate genes.Functionally,these identified genes were mainly involved in diverse metabolism pathways(including lipid biosynthesis).Three cis-elements AW-box([CnTnG](n)7[CG])and AW-boxes like([GnAnC](n)6[GC]/[GnAnC](n)7[G])bound with RcWRI1 were identified.Co-expression network analysis of RcWRI1 further found that RcWRI1 might be widely involved in biosynthesis of storage materials during seed development.In particular,yeast one hybrid experiments found that both AP2 domains within RcWRI1 were required in binding targeted genes.These results not only provide new evidence to understand the regulatory mechanism of RcWRI1 in regulation of oil accumulation during castor bean seed development,but also give candidate gene resource for subsequent genetic improvement toward increasing oil content in oilseed crops.
基金funded by Plant Germplasm Resources Innovation Project of Chinese Academy of Sciences(No.KFJ-BRP-007-002)Yunnan Revitalization Talent Support Program Industrial Innovation Talent Project(Fleagrass Planting and Mosquito Repellent Product Industrialization Research and Development).
文摘Adenosma buchneroides Bonati,also known as fleagrass,is an important medicinal plant used by the Akha(Hani)people of China for treating inflammation-related skin swelling,acne,and diarrhoea,among other conditions.In this study,we aimed to evaluate the anti-inflammatory activities and explore the molecular mechanisms of fleagrass on treating skin swelling and acne.The results demonstrated that fleagrass inhibited the enzymatic activities of 5-LOX and COX-2 in vitro,and decreased the release of NO,IL-6,TNF-α,and IL-10 in the LPS-induced RAW264.7 macrophages.The levels of proteins associated with the nuclear factor-kappa B(NF-κB)pathway were examined by western blotting and immunofluorescence,demonstrating that fleagrass downregulated the expression of TLR4,MyD88,NF-κB/p65,and iNOS and blocked the nuclear translocation of NF-κB/p65.Furthermore,fleagrass exhibited acute anti-inflammatory activity in paw oedema models.The results confirm that fleagrass exhibits remarkable anti-inflammatory activity and can be used in alleviating inflammation,suggesting that fleagrass has the potential to be a novel anti-inflammatory agent.
文摘Carotenoids are important pigments in photosynthetic organisms where they play essential roles in photoreception and photoprotection.Chromochloris zofingiensis is a unicellular green alga that is able to accumulate high amounts of ketocarotenoids including astaxanthin,canthaxanthin and ketolutein when growing heterotrophically or mixotrophically with glucose as a carbon source.Here we elucidate the ketocarotenoid biosynthesis pathway in C.zofingiensis by analyzing five algal mutants.The mutants were shown to have a single nucleotide insertion or substitution in β-carotene ketolase(BKT) gene 1,which resulted in a lack of ketocarotenoid production in Cz-bktl-1,and decreased ketocarote noid co ntent in the other four mutants.These mutants accumulated much higher amounts of non-ketocarotenoids(β-carotene,zeaxanthin and lutein).Interestingly,the Cz-bktl-5 mutant synthesized 2-fold the ketolutein and only 1/30 of the canthaxanthin and astaxanthin as its parent strain,suggesting that the mutated BKT1 exhibits much higher activity in catalyzing lutein to ketolutein but lower activity in ketolating β-carotene and zeaxanthin.Mutant and WT BKT2 gene sequences did not differ.Taken together,we conclude that BKT1 is the key gene involved in ketocarotenoid biosynthesis in C.zofingiensis.Our study provides insight into the biosynthesis of ketocarotenoids in green algae.Furthermore,Cz-bktl mutants may serve as a natural source for the production of zeaxanthin,lutein,and β-carotene.
基金jointly supported by Chinese National Key Technology R & D Program (2015BAD15B02)National Natural Science Foundation of China (31661143002 and 31501034)
文摘Investigation of the relationships of phenotypic and epigenetic variations might he a good way to dissect the genetic or molecular basis of phenotypic variation and plasticity in plants, Castor bean （Ricinus cornraunis L）, an important non-edible oilseed crop, is a mono-species genus plant in the family Euphorbiaceae. Since it displays rich phenotypic variations with low genetic diversity, castor bean is a good model to investigate the molecular basis of phenotypic and epigenetic variations. Cytosine DNA methylation represents a major molecular mechanism of epigenetic occurrence. In this study, epigenetic diversity of sixty landrace accessions collected worldwide was investigated using the methylation- sensitive amplification polymorphism （MSAP） technique, Results showed that the epigenetic diversity （based on the polymorphism of DNA methylated loci） exhibited a medium variation （Ne = 1.395, He = 0.242, I = 0.366） at the population level though the variation was great, ranging from 3,80% to 3431% among accessions. Both population structure analysis and the phylogenetic construction （using the neighbor-joining criteria） revealed that the two main clades were identified, but they did not display a distinct geographic structure, After inspecting the location of polymorphic methylated loci on genome we identified that the polymorphic methylated loci occur widely in nuclear and organelle genomes. This study provides new data to understand phenotypic and epigenetic variations in castor bean,
基金This work was supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB11050200)the National Science Foundation of China(31970274)+1 种基金CAS Youth Innovation Prom otion Association(2018426)the International Partnership Program of the Chinese Academy of Sciences(151853KYSB20170025).
文摘Cuscuta species(dodders)are holoparasites that totally rely on host plants to survive.Although various mobile proteins have been identified to travel within a plant,whether and to what extent protein transfer between Cuscuta and host plants remain unclear.We found that hundreds to more than 1500 proteins were transferred between Cuscuta and the host plants Arabidopsis and soybean,and hundreds of interplant mobile proteins were even detected in the seeds of Cuscuta and the host soybean.Different hosts bridge-connected by dodder were also found to exchange hundreds of proteins.Quantitatively,the mobile proteins represent a few to more than 10%of the proteomes of foreign plants.Using Arabidopsis plants expressing different reporter proteins,we further showed that these reporter proteins could travel between plants and,importantly,retained their activity in the foreign plants.Comparative analysis between the interplant mobile proteins and mRNAs indicated that the majority of mobile proteins were not de novo synthesized from the translocated mRNAs,but bona fide mobile proteins.We propose that large-scale inter-plant protein translocation may play an important role in the interactions between host plants and dodder and even among the dodder bridge-connected hosts.
基金This work was supported by the National Natural Science Foundation of China(32000179 Y.X.)the Strategic Priority Research Program of Chinese Academy of Sciences(XDPB16 J.W.)+2 种基金the CAS"Light of West China"Program(G.S.)the Special Research Assistant of Chinese Academy of Sciences(Y.X.and J.Z.)the Postdoctoral Directional Training Foundation of Yunnan Province(Y.X.).
文摘Orobanchaceae is the largest family of parasiticplants,containing autotrophic and parasiticplants with all degrees of parasitism.This makes it byfar the best family for studying the origin and evolution of plant parasitism.Here we provide three high-quality genomes of orobanchaceous plants,the autotrophic Lindenbergia luchunensis and the holoparasitic plants Phelipanche aegyptiaca and Orobanche cumana.Phylogenomic analysis of these three genomes together with those previously published and the transcriptomes of other orobanchaceous species createda robust phylogeneticframework forOrobanchaceae.We found that an ancient whole-genome duplication(WGD;about 73.48million years ago),which occurred earlierthan theoriginof Orobanchaceae,mighthave contributed totheemergence of parasitism.However,no WGD events occurred in any lineage of orobanchaceous parasites except for Striga after divergence from their autotrophic common ancestor,suggesting that,in contrast with previous speculations,WGD is not associated with the emergence of holoparasitism.We detected evident convergent gene loss in all parasites within Orobanchaceae and between Orobanchaceae and dodder Cuscuta australis.The gene families in the orobanchaceous parasites showed a clear pattern of recent gains and expansions.The expanded gene families are enriched in functions related to the development of the haustorium,suggesting that recent gene family expansions may have facilitated the adaptation of orobanchaceous parasites to different hosts.This study illustrates a stepwise pattern in the evolution of parasitism in the orobanchaceous parasites and will facilitate future studieson parasitism and the control of parasitic plants in agriculture.
