Central metabolism produces carbohydrates and amino acids that are tightly correlated to plant growth and thereby crop productivity.Malate is reported to link mitochondrial respiratory metabolism with cytosolic biosyn...Central metabolism produces carbohydrates and amino acids that are tightly correlated to plant growth and thereby crop productivity.Malate is reported to link mitochondrial respiratory metabolism with cytosolic biosynthetic pathways.Although the function of malate metabolism-related enzymes in providing carbon has been characterized in some plants,evidence for this role in the fleshy fruit of cucumber is lacking.Here,radiolabeled bicarbonate fed into the xylem stream from the cucumber roots was incorporated into amino acids,soluble sugars,and organic acids in the exocarp and vasculature of fruits.The activities of decarboxylases,especially decarboxylation from NADP-dependent malic enzyme(NADP-ME),were higher in cucumber fruit than in the leaf lamina.Histochemical localization revealed that CsNADP-ME2 was mainly located in the exocarp and vascular bundle system of fruit.Radiotracer and gas-exchange analysis indicated that overexpression of CsNADP-ME2 could promote carbon flux into soluble sugars and starch in fruits.Further studies combined with metabolic profiling revealed that the downregulation of CsNADP-ME2 in RNA interference(RNAi)lines caused the accumulation of its substrate,malate,in the exocarp.In addition to inhibition of glycolysis-related gene expression and reduction of the activities of the corresponding enzymes,increased amino acid synthesis and decreased sugar abundance were also observed in these lines.The opposite effect was found in CsNADP-ME2-overexpressing lines,suggesting that there may be a continuous bottom-up feedback regulation of glycolysis in cucumber fruits.Overall,our studies indicate that CsNADP-ME2 may play potential roles in both central carbon reactions and amino acid metabolism in cucumber fruits.展开更多
The Earth’s core is composed of iron,nickel,and a small amount of light elements(e.g.,Si,S,O,C,N,H and P).The thermal conductivities of these components dominate the adiabatic heat flow in the core,which is highly co...The Earth’s core is composed of iron,nickel,and a small amount of light elements(e.g.,Si,S,O,C,N,H and P).The thermal conductivities of these components dominate the adiabatic heat flow in the core,which is highly correlated to geodynamo.Here we review a large number of studies on the electrical and thermal conductivity of iron and iron alloys and discuss their implications on the thermal evolution of the Earth’s core.In summary,we suggest that the Wiedemann-Franz law,commonly used to convert the electrical resistivity to thermal conductivity for metals and alloys,should be cautiously applied under extremely high pressure-temperature(P-T)conditions(e.g.,Earth’s core)because the Lorentz number may be P-T dependent.To date,the discrepancy in the thermal conductivity of iron and iron alloys remains between those from the resistivity measurements and the thermal diffusivity modeling,where the former is systematically larger.Recent studies reconcile the electrical resistivity by first-principles calculation and direct measurements,and this is a good start in resolving this discrepancy.Due to an overall higher thermal conductivity than previously thought,the inner core age is presently constrained at~1.0 Ga.However,light elements in the core would likely lower the thermal conductivity and prolong the crystallization of the inner core.Meanwhile,whether thermal convection can power the dynamo before the inner core formation depends on the amounts of the proper light elements in the core.More works are needed to establish the thermal evolution model of the core.展开更多
Dear Editor,The characteristics and importance of the whitefly Bemisia tabaci as an economic pest seem to continually get more and more attention.Among the whiteflies B.tabaci including,at least 11 genetic groups and ...Dear Editor,The characteristics and importance of the whitefly Bemisia tabaci as an economic pest seem to continually get more and more attention.Among the whiteflies B.tabaci including,at least 11 genetic groups and 36 morphologically indistinguishable cryptic species,invasive MEAMl(Middle East-Asia Minor 1,"B"type)and MED(the Mediterranean,"Q"type)are the 2 most destructive cryptic species of the B.展开更多
Transcriptomes comprise gene co-expression clustersor modules,showcasing distinct patterns of coordinated expression among groups of genes across independent biological samples(Serin et al.,2016).The"guilt-by-ass...Transcriptomes comprise gene co-expression clustersor modules,showcasing distinct patterns of coordinated expression among groups of genes across independent biological samples(Serin et al.,2016).The"guilt-by-association"hypothesis suggests the functional importance of these clusters;for example,co-expressed genes associated with metabolism typically contain genes encoding several enzymes associated with the same pathways.展开更多
The diterpenoid paclitaxel(Taxol)is a chemotherapy medication widely used as a first-line treatment against several types of solid cancers.The supply of paclitaxel from natural sources is limited.However,missing knowl...The diterpenoid paclitaxel(Taxol)is a chemotherapy medication widely used as a first-line treatment against several types of solid cancers.The supply of paclitaxel from natural sources is limited.However,missing knowledge about the genes involved in several specific metabolic steps of paclitaxel biosynthesis has rendered it difficult to engineer the full pathway.In this study,we used a combination of transcriptomics,cell biology,metabolomics,and pathway reconstitution to identify the complete gene set required for the heterologous production of paclitaxel.We identified the missing steps from the current model of paclitaxel biosynthesis and confirmed the activity of most of the missing enzymes via heterologous expression in Nicotiana benthamiana.Notably,we identified a new C4β-C20 epoxidase that could overcome the first bottleneck of metabolic engineering.We used both previously characterized and newly identified oxomutases/epoxidases,taxane 1β-hydroxylase,taxane 9aα-hydroxylase,taxane 9α-dioxygenase,and phenylalanine-CoA ligase,to successfully biosynthesize the key intermediate baccatin Ill and to convert baccatin Ill into paclitaxel in N.benthamiana.In combination,these approaches establisha metabolic route to taxoidbiosynthesis and provide insights into the unique chemistry that plants use to generate complex bioactive metabolites.展开更多
Thermal stress usually leads to excessive production of reactive oxygen species(ROS)in all aerobic organisms.Catalases(CAT)are the key antioxidant enzymes,which act as the first line of defense against ROS in the anti...Thermal stress usually leads to excessive production of reactive oxygen species(ROS)in all aerobic organisms.Catalases(CAT)are the key antioxidant enzymes,which act as the first line of defense against ROS in the antioxidant pathway.The highly invasive and widely distributed whitefly Bemisia tabaci MED damages plants by feeding as well as by transmitting many plant viruses.Previous studies have shown that strong adaptability to high temperature helps explain the spread of MED around the world.However,the mechanism underlying high temperature adaptation of this pest is not well understood.In this study,6 CAT genes were identified from the MED genome and transcriptome dataset,among which BtCAT1,BtCAT2,and BtCAT3 were found to be highly expressed in adults.The expression of BtCAT1,BtCAT2,or BtCAT3 increased with induction temperature and induction time.The MED was exposed with mean high temperature(30℃ or 35℃)and a short-term extremely high temperature(39℃ or 41℃)after the silencing of BtCAT1,BtCAT2,or BtCAT3 to significantly increased ROS levels by at least 0.5 times and significantly decreased survival rate and fecundity of MED adults.The ROS level in the treated specimens gradually returned to a normal level after 24 h at 25℃,but the survival rate still declined significantly.Taken together,our results demonstrate that CAT could help B.tabaci adapt to long-term mean high temperatures and short-term extremely high temperatures by eliminating excessive ROS.展开更多
Detoxification plays a crucial role in agricultural pests to withstand pesticides,and cytochrome P450s,carboxyl/choline esterases(CCEs),and glutathione-S-transferases are the main proteins responsible for their detoxi...Detoxification plays a crucial role in agricultural pests to withstand pesticides,and cytochrome P450s,carboxyl/choline esterases(CCEs),and glutathione-S-transferases are the main proteins responsible for their detoxification ability.The activity of CCEs can be upregulated,downregulated,or modified by mutation.However,few studies have examined the role of alternative splicing in altering the properties of CCEs.We identified 2 variants of TcCCE23 in Tetranychus cinnabarinus:a long version(CCE23-V1)and a short version that is 18 nucleotides shorter than CCE23-V1(CCE23-V2).Whether splicing affects the activity of TcCCE23 remains unclear.Overexpression of CCE23-V2 in fenpropathrin-resistant T.cinnabarinus revealed that splicing affected the detoxification of fenpropathrin by CCE23-V2.The mortality of mites was significantly higher when the expression of CCE23-V2 was knocked down(43.2%±3.3%)via injection of CCE23-dsRNA(double-stranded RNA)compared with the control group injected with green fluorescent protein-dsRNA under fenpropathrin exposure;however,the downregulation of CCE23-V1(61.3%±6.3%)by CCE23-small interfering RNA had no such effect,indicating CCE23-V2 plays a greater role in xenobiotic metabolism than CCE23-V1.The tolerance of flies overexpressing CCE23-V2 to fenpropathrin(50%lethal dose[LD_(50)]=19.47μg/g)was significantly higher than that of Gal4/UAS-CCE23-V1 transgenic flies(LD_(50)=13.11μg/g).Molecular docking analysis showed that splicing opened a“gate”that enlarges the substrate binding cavity of CCE23-V2,might enhance the ability of CCE23-V2 to harbor fenpropathrin molecules.These findings suggest that splicing might enhance the detoxifying capability of TcCCE23.Generally,our data improve the understanding of the diversity and complexity of the mechanisms underlying the regulation of CCEs.展开更多
Orius sauteri(Poppius)(Hemiptera:Anthocoridae)is often used for biological control of small arthropod pests in greenhouse vegetable production systems in Asia.In addition to feeding on arthropod prey,O.sauteri consume...Orius sauteri(Poppius)(Hemiptera:Anthocoridae)is often used for biological control of small arthropod pests in greenhouse vegetable production systems in Asia.In addition to feeding on arthropod prey,O.sauteri consumes small quantities of plant material.Previous studies demonstrated that tomato plant chemistry confers antixenosis resistance to phloem-feeding whiteflies,but the potential nontarget effects of phytochemicals on the beneficial predator O.sauteri are unknown.Comparison of O.sauteri confined to near-isogenic lines(NILs)of tomatoes producing high levels offlavonoids(NIL-purple hypocotyl;resistant to whiteflies)and low levels of flavonoids(NIL-green hypocotyl;susceptible to whiteflies)revealed that O.sauteri had reduced oviposition,nymphal survival,and development on resistant plants,even if they were also provided with prey that did not feed on the host plant.Moreover,O.sauteri showed a significant ovipositional preference in choice assays,laying significantly more eggs on susceptible than on resistant plants.Molecular gut content analysis using the specific chloroplast trnL gene from tomato confirmed that adult and immature O.sauteri feed on both resistant and susceptible genotypes,and feeding behavior assays revealed that resistance did not affect plant feeding or prey acceptance by O.sauteri adults.These results demonstrate a direct negative effect of phytochemicals on a nontarget beneficial species and indicate that resistance mediated by phytochemicals can affect organisms that do not solely feed on phloem sap.The results also indicate that the mode of action and the potential ecological effects of phytochemicalmediated resistance are broader than previously recognized.展开更多
Tomato spotted wilt orthotospovirus(TSWV)causes substantial economic losses to vegetables and other crops.TSWV is mainly transmitted by thrips in a persistent and proliferative manner,and its most efficient vector is ...Tomato spotted wilt orthotospovirus(TSWV)causes substantial economic losses to vegetables and other crops.TSWV is mainly transmitted by thrips in a persistent and proliferative manner,and its most efficient vector is the western flower thrips,Frankliniella occidentalis(Pergande).In moving from the thrips midgut to the salivary glands in preparation for transmission,the virions must overcome multiple barriers.Although several proteins that interact with TSWV in thrips have been characterized,we hypothesized that additional thrips proteins interact with TSWV and facilitate its transmission.In the current study,67 F occidentalis proteins that interact with GN(a structural glycoprotein)were identified using a split-ubiquitin membrane-based yeast 2-hybrid(MbY2H)system.Three proteins,apolipoprotein-D(ApoD),orai-2-like(Orai),and obstructor-E-like isoform X2(Obst),were selected for further study based on their high abundance and interaction strength;their interactions with Gn were confirmed by MbY2H,yeastβ-galactosidase and luciferase complementation assays.The relative expressions of ApoD and Orai were significantly down-regulated but that of Obst was significantly up-regulated in viruliferous thrips.When interfering with Obst in larval stage,the TSWV acquisition rate in 3 independent experiments was significantly decreased by 26%,40%,and 35%,respectively.In addition,when Obst was silenced in adults,the virus titer was significantly decreased,and the TSWV transmission rate decreased from 66.7%to 31.9%using the leaf disk method and from 86.67%to 43.33%using the living plant method.However,the TSWV acquisition and transmission rates were not affected by interference with the ApoD or Orai gene.The results indicate that Obst may play an important role in TSWV acquisition and transmission in Frankliniella occidentalis.展开更多
Inherited bacterial symbionts are very common in arthropods, but infection frequency can vary widely among populations. Experiments and interpopulation comparisons suggest that host genetic background might be importa...Inherited bacterial symbionts are very common in arthropods, but infection frequency can vary widely among populations. Experiments and interpopulation comparisons suggest that host genetic background might be important in explaining this variation. Our extensive field investigation showed that the infection pattern of the facultative symbiont Cardinium was heterogeneous across geographical populations of the invasive whitefly Bemisia tabaci Mediterranean (MED) in China, with genetic nuclear differences evident in 2 of the populations: 1 with a low infection rate (SD line) and 1 with a high infection rate (HaN line). However, whether the heterogeneous frequency of Cardinium is associated with the host genetic background remains poorly understood. Here, we compared the fitness of the Cardinium-infected and uninfected sublines with similar nuclear genetic backgrounds from SD and HaN lines, respectively, and further determine whether host extranuclear or nuclear genotype influenced the Cardinium–host phenotype by performing 2 new introgression series of 6 generations between SD and HaN lines (i.e., Cardinium-infected females of SD were backcrossed with uninfected males of HaN, and vice versa). The results showed that Cardinium provides marginal fitness benefits in the SD line, whereas Cardinium provides strong fitness benefits in the HaN line. Further, both Cardinium and the Cardinium–host nuclear interaction influence the fecundity and pre-adult survival rate of B. tabaci, whereas the extranuclear genotype does not. In conclusion, our results provide evidence that Cardinium-mediated fitness effects were closely associated with the host genetic background, which provides a fundamental basis for understanding the mechanism underlying the heterogeneous distribution of Cardinium in B. tabaci MED populations across China.展开更多
Protein complexes are important for almost all biological processes.Hence,to fully understand how cells work,it is also necessary to characterize protein complexes and their dynamics in response to various cellular cu...Protein complexes are important for almost all biological processes.Hence,to fully understand how cells work,it is also necessary to characterize protein complexes and their dynamics in response to various cellular cues.Moreover,the dynamics of protein interaction play crucial roles in regulating the(dis)association of protein complexes and,in turn,regulating biological processes such as metabolism.Here,mitochondrial protein complexes were investigated by blue native PAGE and size-exclusion chromatography under conditions of oxidative stress in order to monitor their dynamic(dis)associations.Rearrangements of enzyme interactions and changes in protein complex abundance were observed in response to oxidative stress induced by menadione treatment.These included changes in enzymatic protein complexes involving g-amino butyric acid transaminase(GABA-T),D-ornithine aminotransferase(D-OAT),or proline dehydrogenase 1(POX1)that are expected to affect proline metabolism.Menadione treatment also affected interactions between several enzymes of the tricarboxylic acid(TCA)cycle and the abundance of complexes of the oxidative phosphorylation pathway.In addition,we compared the mitochondrial complexes of roots and shoots.Considerable differences between the two tissues were observed in the mitochondrial import/export apparatus,the formation of super-complexes in the oxidative phosphorylation pathway,and specific interactions between enzymes of the TCA cycle that we postulate may be related to the metabolic/energetic requirements of roots and shoots.展开更多
While the structures of plant primary metabolic pathways are generally well defined and highly conserved across species,those defining specialized metabolism are less well characterized and more highly variable across...While the structures of plant primary metabolic pathways are generally well defined and highly conserved across species,those defining specialized metabolism are less well characterized and more highly variable across species.In this study,we investigated polyphenolic metabolism in the lycopersicum complex by characterizing the underlying biosynthetic and decorative reactions that constitute the metabolic network of polyphenols across eight different species of tomato.For this purpose,GC-MS-and LC-MS-based metabolomics of different tissues of Solatium lycopersicum and wild tomato species were carried out,in concert with the evaluation of cross-hybridized microarray data for MapMan-based transcriptomic analysis,and publicly available RNA-sequencing data for annotation of biosynthetic genes.The combined data were used to compile species-specific metabolic networks of polyphenolic metabolism,allowing the establishment of an entire pan-species biosynthetic framework as well as annotation of the functions of decoration enzymes involved in the formation of metabolic diversity of the flavonoid pathway.The combined results are discussed in the context of the current understanding of tomato flavonol biosynthesis as well as a global view of metabolic shifts during fruit ripening.Our results provide an example as to how large-scale biology approaches can be used for the definition and refinement of large specialized metabolism pathways.展开更多
RNA interference(RNAi)has emerged as a powerful tool for developing novel management strategies for controlling insect pests.The 28-spotted ladybeetle,Henosepilachna vigintioctopunctata is one of the most important pe...RNA interference(RNAi)has emerged as a powerful tool for developing novel management strategies for controlling insect pests.The 28-spotted ladybeetle,Henosepilachna vigintioctopunctata is one of the most important pests attacking solanaceous plants in Asia.In this study,the potential of dietary RNAi to manage H.vigintioctopunctata was investigated using both in vitro synthesized and bacterially expressed double-stranded RNAs(dsRNAs)of HvvATPase A and HvvATPase E.The expression levels of HvvATPase A and HvvATPase E were higher in Malpighian tubules than in other tissue types.The silencing of HvvATPase A and HvvATPase E led to significant mortality in H.vigintioctopunctata larvae.In addition,the ingestion of HvvATPase A and HvvATPase E significantly deterred feeding behavior and subsequently arrested the development of H.vigintioctopunctata.Notably,the bacterially expressed dsRNAs consistently caused higher mortality in larvae and adults.Finally,the nontarget effects of the dsRNAs of H.vigintioctopunctata on the predatory ladybeetle Propylaea japonica were evaluated.P.japonica 1st instar larvae were administered vATPase A and vATPase E dsRNAs from H.vigintioctopunctata and P.japonica under the worst-case scenario,in which dsGFP served as negative control.There were significant effects of dsHvvATPase A on P.japonica at the transcriptional level but not at the organismal level,whereas dsHvvATPase E did not effect P.japonica at either the transcriptional or the organismal level.Collectively,the results of the study suggest that HvvATPase A and HvvATPase E can act as novel molecular targets for the control of H.vigintioctopunctata.展开更多
The tricarboxylic acid(TCA) cycle is one of the canonical energy pathways of living systems, as well as being an example of a pathway in which dynamic enzyme assemblies, or metabolons, are well characterized. The role...The tricarboxylic acid(TCA) cycle is one of the canonical energy pathways of living systems, as well as being an example of a pathway in which dynamic enzyme assemblies, or metabolons, are well characterized. The role of the enzymes have been the subject of saturated transgenesis approaches, whereby the expression of the constituent enzymes were reduced or knocked out in order to ascertain their in vivo function.Some of the resultant plants exhibited improved photosynthesis and plant growth, under controlled greenhouse conditions. In addition, overexpression of the endogenous genes, or heterologous forms of a number of the enzymes, has been carried out in tomato fruit and the roots of a range of species, and in some instances improvement in fruit yield and postharvest properties and plant performance, under nutrient limitation, have been reported, respectively. Given a number of variants, in nature, we discuss possible synthetic approaches involving introducing these variants, or at least a subset of them, into plants. We additionally discuss the likely consequences of introducing synthetic metabolons, wherein certain pairs of reactions are artificially permanently assembled into plants, and speculate as to future strategies to further improve plant productivity by manipulation of the core metabolic pathway.展开更多
Taxaceae is the yew family of conifers and includes evergreen trees and small shrubs mainly distributed in Eurasia and North America.The genus of Taxus has attracted considerable attention since Monroe E.Wall and Mans...Taxaceae is the yew family of conifers and includes evergreen trees and small shrubs mainly distributed in Eurasia and North America.The genus of Taxus has attracted considerable attention since Monroe E.Wall and Mansukh C.Wani firstly isolated and characterized an unusual cyclic diterpenoid from the bark of the Pacific yew tree(Wani et al.,1971).This compound,subsequently called paclitaxel,was shown to promote tubulin assembly into microtubules,preventing their disassembly.Subsequently,paclitaxel was approved for medical use against ovarian cancer in 1992(Fischer and Ganellin,2010).展开更多
Although the use of stable transformation technology has led to great insight into gene function,its application in high-throughput studies remains arduous.Agro-infiltration have been widely used in species such as Ni...Although the use of stable transformation technology has led to great insight into gene function,its application in high-throughput studies remains arduous.Agro-infiltration have been widely used in species such as Nicotiana benthamiana for the rapid detection of gene expression and protein interaction analysis,but this technique does not work efficiently in other plant species,including Arabidopsis thaliana.As an efficient high-throughput transient expression system is currently lacking in the model plant species A.thaliana,we developed a method that is characterized by high efficiency,reproducibility,and suitability for transient expression of a variety of functional proteins in A.thaliana and 7 other plant species,including Brassica oleracea,Capsella rubella,Thellungiella salsuginea,Thellungiella halophila,Solanum tuberosum,Capsicum annuum,and N.benthamiana.Efficiency of this method was independently verified in three independent research facilities,pointing to the robustness of this technique.Furthermore,in addition to demonstrating the utility of this technique in a range of species,we also present a case study employing this method to assess protein–protein interactions in the sucrose biosynthesis pathway in Arabidopsis.展开更多
The two-spotted spider mite Tetranychus urticate is an important agricultural pest worldwide.It is extremely polyphagous and has developed resistance to many pesticides.Here,we assessed the pesticide resistance of sev...The two-spotted spider mite Tetranychus urticate is an important agricultural pest worldwide.It is extremely polyphagous and has developed resistance to many pesticides.Here,we assessed the pesticide resistance of seven field populations of T.urticae in China,their target site mutations and the activities of their detoxification enzymes.The results showed that abamectin and the traditional pesticides pyridaben,profenofos and bifenthrin had higher resistance or lower toxicity than more recently developed pesticides including chlorfenapyr,spinetoram,cyflumetofen,cyenopyrafen,bifenazate and B-azolemiteacrylic.The frequency of point mutations related to abamectin resistance,G314D in the glutamate-gated chloride channel 1(GluCl1)and G326E in GluC13,ranged 47%-70%and 0%-97%,respectively.The frequency of point mutations in A1215D and F1538I of the voltage-gated sodium channel gene(VGSC),which may increase resistance to pyrethroids,ranged 88%-100%and 10%-100%,respectively.For target sites related to organophosphate resistance,mutation frequencies ranged 25%-92%for G119S and 0%-23%for A201S in the acetycholinesterase gene(Ace).Mutation G126S in the bifenazate resistance-related cytochrome b gene(Cytb)was observed in three of the seven T.urticae populations.Higher activities of detoxification enzymes(P450,GST,CarEs and UGTs)were observed in two T.urticae populations,with significant difference in the XY-SX population.These results provide useful information on the status of pesticide resistance of T.urticae in China and suggest that T.urticae field populations may have multiple resistance mechanisms.展开更多
Despite species-specifc diferences in the pathways of respiratory metabolism are remarkably conserved across the kingdoms of life with glycolysis,the tricarboxylic acid cycle,and mitochondrial electron transport chain...Despite species-specifc diferences in the pathways of respiratory metabolism are remarkably conserved across the kingdoms of life with glycolysis,the tricarboxylic acid cycle,and mitochondrial electron transport chain representing the major components of the process in the vast majority of organisms.In addition to being of critical importance in fueling life itself these pathways serve as interesting case studies for substrate channelling with research on this theme having been carried out for over 40 years.Here we provide a cross-kingdom review of the ample evidence for protein-protein interaction and enzyme assemblies within the three component pathways as well as describing the scarcer available evidence for substrate channelling itself.展开更多
Metabolons are transientmulti-protein complexes of sequential enzymes that mediate substrate channeling.They differ from multi-enzyme complexes in that they are dynamic,rather than permanent,and as such have considera...Metabolons are transientmulti-protein complexes of sequential enzymes that mediate substrate channeling.They differ from multi-enzyme complexes in that they are dynamic,rather than permanent,and as such have considerably lower dissociation constants.Despite the fact that a huge number of metabolons have been suggested to exist in plants,most of these claims are erroneous as only a handful of these have been proven to channelmetabolites.We believe that physical protein-protein interactions between consecutive enzymes of a pathway should rather be called enzyme-enzyme assemblies.In this review,we describe how metabolons are generally assembled by transient interactions and held together by both structural elements and non-covalent interactions.Experimental evidence for their existence comes fromprotein-protein interaction studies,which indicate that the enzymes physically interact,and direct substrate channelingmeasurements,which indicate that they functionally interact.Unfortunately,advances in cell biology and proteomics have far outstripped those in classical enzymology and flux measurements,rendering most reports reliant purely on interactome studies.Recent developments in co-fractionation mass spectrometry will likely further exacerbate this bias.Given this,only dynamic enzyme-enzyme assemblies in which both physical and functional interactions have been demonstrated should be termed metabolons.We discuss the level of evidence for the manifold plant pathways that have been postulated to contain metabolons and then list examples in both primary and secondary metabolism for which strong evidence has been provided to support these claims.In doing so,we pay particular attention to experimental and mathematical approaches to study metabolons as well as complexities that arise in attempting to follow them.Finally,we discuss perspectives for improving our understanding of these fascinating but enigmatic interactions.展开更多
Plant glandular trichomes are epidermal secretory structures that are important for plant resistance to pests.Although several regulatory genes have been characterized in trichome development,the molecular mechanisms ...Plant glandular trichomes are epidermal secretory structures that are important for plant resistance to pests.Although several regulatory genes have been characterized in trichome development,the molecular mechanisms conferring glandular trichome morphogenesis are unclear.We observed the differences in trichomes in cultivated tomato cv.‘Moneymaker’(MM) and the wild species Solanum pimpinellifolium PI365967 (PP),and used a recombinant inbred line (RIL) population to identify the genes that control trichome development in tomato.We found that the genomic variations in two genes,HAIR (H) and SPARSE HAIR (SH),contribute to the trichome differences between MM and PP.H and SH encode two paralogous C2H2 zinc-finger proteins that function redundantly in regulating trichome formation.Loss-offunction h/sh double mutants exhibited a significantly decreased number of Type I trichomes and complete loss of long stalk trichomes.Molecular and genetic analyses further indicate that H and SH act upstream of ZFP5.Overexpression of ZFP5 partially restored the trichome defects in NIL-h;sh;.Moreover,H and SH expression is induced by high temperatures,and their mutations inhibit the elongation of trichomes that reduce the plant repellent to whiteflies.Our findings confirm that H and SH are two vital transcription factors controlling initiation and elongation of Type I and III multicellular trichomes in tomato.展开更多
基金This work was supported by the National Natural Science Foundation of China(32272695 and 31972398 to X.S.)the National Key Research and Development Program of China(2019YFD1000300)+3 种基金the National Natural Science Foundation of China(31960591 to N.S.)the Max-Planck Society and European Union’s Horizon 2020 research and innovation programme,project PlantaSYST(SGA-CSA No.664621 and No.739582 under FPA No.664620)the China Agriculture Research System of MOF and MARA(CARS-23)the 111 Project of Ministry of Education of P.R.C.(B17043).
文摘Central metabolism produces carbohydrates and amino acids that are tightly correlated to plant growth and thereby crop productivity.Malate is reported to link mitochondrial respiratory metabolism with cytosolic biosynthetic pathways.Although the function of malate metabolism-related enzymes in providing carbon has been characterized in some plants,evidence for this role in the fleshy fruit of cucumber is lacking.Here,radiolabeled bicarbonate fed into the xylem stream from the cucumber roots was incorporated into amino acids,soluble sugars,and organic acids in the exocarp and vasculature of fruits.The activities of decarboxylases,especially decarboxylation from NADP-dependent malic enzyme(NADP-ME),were higher in cucumber fruit than in the leaf lamina.Histochemical localization revealed that CsNADP-ME2 was mainly located in the exocarp and vascular bundle system of fruit.Radiotracer and gas-exchange analysis indicated that overexpression of CsNADP-ME2 could promote carbon flux into soluble sugars and starch in fruits.Further studies combined with metabolic profiling revealed that the downregulation of CsNADP-ME2 in RNA interference(RNAi)lines caused the accumulation of its substrate,malate,in the exocarp.In addition to inhibition of glycolysis-related gene expression and reduction of the activities of the corresponding enzymes,increased amino acid synthesis and decreased sugar abundance were also observed in these lines.The opposite effect was found in CsNADP-ME2-overexpressing lines,suggesting that there may be a continuous bottom-up feedback regulation of glycolysis in cucumber fruits.Overall,our studies indicate that CsNADP-ME2 may play potential roles in both central carbon reactions and amino acid metabolism in cucumber fruits.
基金financial support from the National Natural Science Foundation of China(Grant Nos.41804082 and 41873073)the Special Research Assistant Funding Program provided by the Chinese Academy of Sciences。
文摘The Earth’s core is composed of iron,nickel,and a small amount of light elements(e.g.,Si,S,O,C,N,H and P).The thermal conductivities of these components dominate the adiabatic heat flow in the core,which is highly correlated to geodynamo.Here we review a large number of studies on the electrical and thermal conductivity of iron and iron alloys and discuss their implications on the thermal evolution of the Earth’s core.In summary,we suggest that the Wiedemann-Franz law,commonly used to convert the electrical resistivity to thermal conductivity for metals and alloys,should be cautiously applied under extremely high pressure-temperature(P-T)conditions(e.g.,Earth’s core)because the Lorentz number may be P-T dependent.To date,the discrepancy in the thermal conductivity of iron and iron alloys remains between those from the resistivity measurements and the thermal diffusivity modeling,where the former is systematically larger.Recent studies reconcile the electrical resistivity by first-principles calculation and direct measurements,and this is a good start in resolving this discrepancy.Due to an overall higher thermal conductivity than previously thought,the inner core age is presently constrained at~1.0 Ga.However,light elements in the core would likely lower the thermal conductivity and prolong the crystallization of the inner core.Meanwhile,whether thermal convection can power the dynamo before the inner core formation depends on the amounts of the proper light elements in the core.More works are needed to establish the thermal evolution model of the core.
基金The authors would like to thank Dr.Zhangjun Fei(Boyce Thompson Institute,USA)for computational support and comments on an earlier draft.This research was supported by the National Key R&D Program of China(2022YFD1400800)National Natural Science Foundation of China(32272534 and 32161143020)+5 种基金the Hainan Major Science and Technology Project(ZDKJ2021007)the Beijing Key Laboratory for Pest Control and Sustainable Cultivation of Vegetables and the Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences(CAAS-ASTIP-IVFCAAS)The funders had no role in study design,data collection and analysis,decision to publish,or preparation of the manuscript.Data Availability Statement This Whole Genome Shotgun project(Bemisia tabaci MED,Asial,Asialll,AsialI6,and AsialI7)has been deposited at DDBJ/ENA/GenBank under accession VMOE00000000,VMEI00000000,VMEH00000000,VMEG00000000,and VLTD00000000,respectively.Raw sequences including Illumina,PacBio,Hi-C,and RNA-seq reads have been deposited in the NCBI SRA)under accessions SRR11649531-SRR11649533(MED)SRR11692174-SRR11692176(Asial),SRR11613039-SRR11613041(AsiaII1)SRR11609251-SRR11609253(Asiall6)SRR11609258-SRR11609260(Asial7).The genome and predicted gene sequences of all available whitefly genomes are also available via the Whitefly Genome Database(WF-DB,http:/82.157.25.63/whitefly/homepage.php).
文摘Dear Editor,The characteristics and importance of the whitefly Bemisia tabaci as an economic pest seem to continually get more and more attention.Among the whiteflies B.tabaci including,at least 11 genetic groups and 36 morphologically indistinguishable cryptic species,invasive MEAMl(Middle East-Asia Minor 1,"B"type)and MED(the Mediterranean,"Q"type)are the 2 most destructive cryptic species of the B.
文摘Transcriptomes comprise gene co-expression clustersor modules,showcasing distinct patterns of coordinated expression among groups of genes across independent biological samples(Serin et al.,2016).The"guilt-by-association"hypothesis suggests the functional importance of these clusters;for example,co-expressed genes associated with metabolism typically contain genes encoding several enzymes associated with the same pathways.
基金the Max Planck Society(Y.Z-.,S.A.,L.P.d.S.,F.S.,and A.R.F.),and Y.Z.,S.A.,and A.R.F.acknowledge the European Union's Horizon 2020 research and innovation programme,project PlantaSYST(SGA-CSA No.739582 under FPA No.664620)the BG05M2OP001-1.003-001-C01 project,financed by the European Regional Development Fund through the Bulgarian"Science and Education for Smart Growth"Operational Programme.J.J.M.thanks the Fonds der Chemischen Industrie,FCI for funding,H.F.thanks the Chinese Scholarship Councilfor funding.
文摘The diterpenoid paclitaxel(Taxol)is a chemotherapy medication widely used as a first-line treatment against several types of solid cancers.The supply of paclitaxel from natural sources is limited.However,missing knowledge about the genes involved in several specific metabolic steps of paclitaxel biosynthesis has rendered it difficult to engineer the full pathway.In this study,we used a combination of transcriptomics,cell biology,metabolomics,and pathway reconstitution to identify the complete gene set required for the heterologous production of paclitaxel.We identified the missing steps from the current model of paclitaxel biosynthesis and confirmed the activity of most of the missing enzymes via heterologous expression in Nicotiana benthamiana.Notably,we identified a new C4β-C20 epoxidase that could overcome the first bottleneck of metabolic engineering.We used both previously characterized and newly identified oxomutases/epoxidases,taxane 1β-hydroxylase,taxane 9aα-hydroxylase,taxane 9α-dioxygenase,and phenylalanine-CoA ligase,to successfully biosynthesize the key intermediate baccatin Ill and to convert baccatin Ill into paclitaxel in N.benthamiana.In combination,these approaches establisha metabolic route to taxoidbiosynthesis and provide insights into the unique chemistry that plants use to generate complex bioactive metabolites.
基金supported by grants from the National Natural Science Foundation of China(31871970,32221004,and 32272534)the Hainan Major Science and Technology Project(ZDKJ2021007)+1 种基金the Project of Sanya Yazhou Bay Science and Technology City(SKJC-2022-PTDX-017)the Research and demonstration of key technologies for ensuring supply of vegetable industry(2020-J-005-ydhz).
文摘Thermal stress usually leads to excessive production of reactive oxygen species(ROS)in all aerobic organisms.Catalases(CAT)are the key antioxidant enzymes,which act as the first line of defense against ROS in the antioxidant pathway.The highly invasive and widely distributed whitefly Bemisia tabaci MED damages plants by feeding as well as by transmitting many plant viruses.Previous studies have shown that strong adaptability to high temperature helps explain the spread of MED around the world.However,the mechanism underlying high temperature adaptation of this pest is not well understood.In this study,6 CAT genes were identified from the MED genome and transcriptome dataset,among which BtCAT1,BtCAT2,and BtCAT3 were found to be highly expressed in adults.The expression of BtCAT1,BtCAT2,or BtCAT3 increased with induction temperature and induction time.The MED was exposed with mean high temperature(30℃ or 35℃)and a short-term extremely high temperature(39℃ or 41℃)after the silencing of BtCAT1,BtCAT2,or BtCAT3 to significantly increased ROS levels by at least 0.5 times and significantly decreased survival rate and fecundity of MED adults.The ROS level in the treated specimens gradually returned to a normal level after 24 h at 25℃,but the survival rate still declined significantly.Taken together,our results demonstrate that CAT could help B.tabaci adapt to long-term mean high temperatures and short-term extremely high temperatures by eliminating excessive ROS.
基金supported in part by the National Nature Sciences Foundation(32001935 and 31972297)the Fundamental Research Funds for the Central Universities(SWU-KR22005).
文摘Detoxification plays a crucial role in agricultural pests to withstand pesticides,and cytochrome P450s,carboxyl/choline esterases(CCEs),and glutathione-S-transferases are the main proteins responsible for their detoxification ability.The activity of CCEs can be upregulated,downregulated,or modified by mutation.However,few studies have examined the role of alternative splicing in altering the properties of CCEs.We identified 2 variants of TcCCE23 in Tetranychus cinnabarinus:a long version(CCE23-V1)and a short version that is 18 nucleotides shorter than CCE23-V1(CCE23-V2).Whether splicing affects the activity of TcCCE23 remains unclear.Overexpression of CCE23-V2 in fenpropathrin-resistant T.cinnabarinus revealed that splicing affected the detoxification of fenpropathrin by CCE23-V2.The mortality of mites was significantly higher when the expression of CCE23-V2 was knocked down(43.2%±3.3%)via injection of CCE23-dsRNA(double-stranded RNA)compared with the control group injected with green fluorescent protein-dsRNA under fenpropathrin exposure;however,the downregulation of CCE23-V1(61.3%±6.3%)by CCE23-small interfering RNA had no such effect,indicating CCE23-V2 plays a greater role in xenobiotic metabolism than CCE23-V1.The tolerance of flies overexpressing CCE23-V2 to fenpropathrin(50%lethal dose[LD_(50)]=19.47μg/g)was significantly higher than that of Gal4/UAS-CCE23-V1 transgenic flies(LD_(50)=13.11μg/g).Molecular docking analysis showed that splicing opened a“gate”that enlarges the substrate binding cavity of CCE23-V2,might enhance the ability of CCE23-V2 to harbor fenpropathrin molecules.These findings suggest that splicing might enhance the detoxifying capability of TcCCE23.Generally,our data improve the understanding of the diversity and complexity of the mechanisms underlying the regulation of CCEs.
基金supported by the National Natural Science Foundation of China(31872930,32172388)the National Key Research and Development Plan(2017YFD0200400)+1 种基金the Science and Technology Innovation Program of the Chinese Academy of Agricultural Science(CAAS-ASTIP-IVFCAAS)the Beijing Key Laboratory for Pest Control and Sustainable Cultivation of Vegetables.
文摘Orius sauteri(Poppius)(Hemiptera:Anthocoridae)is often used for biological control of small arthropod pests in greenhouse vegetable production systems in Asia.In addition to feeding on arthropod prey,O.sauteri consumes small quantities of plant material.Previous studies demonstrated that tomato plant chemistry confers antixenosis resistance to phloem-feeding whiteflies,but the potential nontarget effects of phytochemicals on the beneficial predator O.sauteri are unknown.Comparison of O.sauteri confined to near-isogenic lines(NILs)of tomatoes producing high levels offlavonoids(NIL-purple hypocotyl;resistant to whiteflies)and low levels of flavonoids(NIL-green hypocotyl;susceptible to whiteflies)revealed that O.sauteri had reduced oviposition,nymphal survival,and development on resistant plants,even if they were also provided with prey that did not feed on the host plant.Moreover,O.sauteri showed a significant ovipositional preference in choice assays,laying significantly more eggs on susceptible than on resistant plants.Molecular gut content analysis using the specific chloroplast trnL gene from tomato confirmed that adult and immature O.sauteri feed on both resistant and susceptible genotypes,and feeding behavior assays revealed that resistance did not affect plant feeding or prey acceptance by O.sauteri adults.These results demonstrate a direct negative effect of phytochemicals on a nontarget beneficial species and indicate that resistance mediated by phytochemicals can affect organisms that do not solely feed on phloem sap.The results also indicate that the mode of action and the potential ecological effects of phytochemicalmediated resistance are broader than previously recognized.
基金the China Agriculture Research System(CARS-24-C-02)the National Natural Science Foundation of China(32272548)+1 种基金the Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences(CAAS-ASTIP-IVFCAAS)the Hainan Major Science and Technology Project(ZDKJ2021007)。
文摘Tomato spotted wilt orthotospovirus(TSWV)causes substantial economic losses to vegetables and other crops.TSWV is mainly transmitted by thrips in a persistent and proliferative manner,and its most efficient vector is the western flower thrips,Frankliniella occidentalis(Pergande).In moving from the thrips midgut to the salivary glands in preparation for transmission,the virions must overcome multiple barriers.Although several proteins that interact with TSWV in thrips have been characterized,we hypothesized that additional thrips proteins interact with TSWV and facilitate its transmission.In the current study,67 F occidentalis proteins that interact with GN(a structural glycoprotein)were identified using a split-ubiquitin membrane-based yeast 2-hybrid(MbY2H)system.Three proteins,apolipoprotein-D(ApoD),orai-2-like(Orai),and obstructor-E-like isoform X2(Obst),were selected for further study based on their high abundance and interaction strength;their interactions with Gn were confirmed by MbY2H,yeastβ-galactosidase and luciferase complementation assays.The relative expressions of ApoD and Orai were significantly down-regulated but that of Obst was significantly up-regulated in viruliferous thrips.When interfering with Obst in larval stage,the TSWV acquisition rate in 3 independent experiments was significantly decreased by 26%,40%,and 35%,respectively.In addition,when Obst was silenced in adults,the virus titer was significantly decreased,and the TSWV transmission rate decreased from 66.7%to 31.9%using the leaf disk method and from 86.67%to 43.33%using the living plant method.However,the TSWV acquisition and transmission rates were not affected by interference with the ApoD or Orai gene.The results indicate that Obst may play an important role in TSWV acquisition and transmission in Frankliniella occidentalis.
基金supported by the National Key R&D Program of China(2022YFD1401200)Taishan Scholar Foundation of Shandong Province of China(tstp20221135)the National Nature Science Foun-dation of China(31872030 and 31572064).
文摘Inherited bacterial symbionts are very common in arthropods, but infection frequency can vary widely among populations. Experiments and interpopulation comparisons suggest that host genetic background might be important in explaining this variation. Our extensive field investigation showed that the infection pattern of the facultative symbiont Cardinium was heterogeneous across geographical populations of the invasive whitefly Bemisia tabaci Mediterranean (MED) in China, with genetic nuclear differences evident in 2 of the populations: 1 with a low infection rate (SD line) and 1 with a high infection rate (HaN line). However, whether the heterogeneous frequency of Cardinium is associated with the host genetic background remains poorly understood. Here, we compared the fitness of the Cardinium-infected and uninfected sublines with similar nuclear genetic backgrounds from SD and HaN lines, respectively, and further determine whether host extranuclear or nuclear genotype influenced the Cardinium–host phenotype by performing 2 new introgression series of 6 generations between SD and HaN lines (i.e., Cardinium-infected females of SD were backcrossed with uninfected males of HaN, and vice versa). The results showed that Cardinium provides marginal fitness benefits in the SD line, whereas Cardinium provides strong fitness benefits in the HaN line. Further, both Cardinium and the Cardinium–host nuclear interaction influence the fecundity and pre-adult survival rate of B. tabaci, whereas the extranuclear genotype does not. In conclusion, our results provide evidence that Cardinium-mediated fitness effects were closely associated with the host genetic background, which provides a fundamental basis for understanding the mechanism underlying the heterogeneous distribution of Cardinium in B. tabaci MED populations across China.
基金supported by funding from the Max Planck Society(S.M.J.,A.G.,A.R.F.,and Y.Z.)the European Union’s Horizon 2020 research and innovation program,project PlantaSYST(SGA-CSA no.739582 under FPA no.664620)for supporting their researchfinancial support from the IMPRS-PMPG program.
文摘Protein complexes are important for almost all biological processes.Hence,to fully understand how cells work,it is also necessary to characterize protein complexes and their dynamics in response to various cellular cues.Moreover,the dynamics of protein interaction play crucial roles in regulating the(dis)association of protein complexes and,in turn,regulating biological processes such as metabolism.Here,mitochondrial protein complexes were investigated by blue native PAGE and size-exclusion chromatography under conditions of oxidative stress in order to monitor their dynamic(dis)associations.Rearrangements of enzyme interactions and changes in protein complex abundance were observed in response to oxidative stress induced by menadione treatment.These included changes in enzymatic protein complexes involving g-amino butyric acid transaminase(GABA-T),D-ornithine aminotransferase(D-OAT),or proline dehydrogenase 1(POX1)that are expected to affect proline metabolism.Menadione treatment also affected interactions between several enzymes of the tricarboxylic acid(TCA)cycle and the abundance of complexes of the oxidative phosphorylation pathway.In addition,we compared the mitochondrial complexes of roots and shoots.Considerable differences between the two tissues were observed in the mitochondrial import/export apparatus,the formation of super-complexes in the oxidative phosphorylation pathway,and specific interactions between enzymes of the TCA cycle that we postulate may be related to the metabolic/energetic requirements of roots and shoots.
基金T.T and A.R.F.gratefully acknowledge partial support by the Max Planck Society and NAIST(to T.T.)as well as the European Union Projects(TOMGEM,MultiBioPro,and PlantaSyst).Research activity of T.T.was additionally supported by the Alexander von Humboldt Foundation(7000228060 to T.T.)the JSPS KAKENHI Grant-in-Aid for Scientific Research B(19H03249 to T.T.)C(19K06723 to M.W.).
文摘While the structures of plant primary metabolic pathways are generally well defined and highly conserved across species,those defining specialized metabolism are less well characterized and more highly variable across species.In this study,we investigated polyphenolic metabolism in the lycopersicum complex by characterizing the underlying biosynthetic and decorative reactions that constitute the metabolic network of polyphenols across eight different species of tomato.For this purpose,GC-MS-and LC-MS-based metabolomics of different tissues of Solatium lycopersicum and wild tomato species were carried out,in concert with the evaluation of cross-hybridized microarray data for MapMan-based transcriptomic analysis,and publicly available RNA-sequencing data for annotation of biosynthetic genes.The combined data were used to compile species-specific metabolic networks of polyphenolic metabolism,allowing the establishment of an entire pan-species biosynthetic framework as well as annotation of the functions of decoration enzymes involved in the formation of metabolic diversity of the flavonoid pathway.The combined results are discussed in the context of the current understanding of tomato flavonol biosynthesis as well as a global view of metabolic shifts during fruit ripening.Our results provide an example as to how large-scale biology approaches can be used for the definition and refinement of large specialized metabolism pathways.
基金supported by the National Key R&D Program of China(2017YFD0200900)National Natural Science Foundation of China(31972269)GDUPS(2017).
文摘RNA interference(RNAi)has emerged as a powerful tool for developing novel management strategies for controlling insect pests.The 28-spotted ladybeetle,Henosepilachna vigintioctopunctata is one of the most important pests attacking solanaceous plants in Asia.In this study,the potential of dietary RNAi to manage H.vigintioctopunctata was investigated using both in vitro synthesized and bacterially expressed double-stranded RNAs(dsRNAs)of HvvATPase A and HvvATPase E.The expression levels of HvvATPase A and HvvATPase E were higher in Malpighian tubules than in other tissue types.The silencing of HvvATPase A and HvvATPase E led to significant mortality in H.vigintioctopunctata larvae.In addition,the ingestion of HvvATPase A and HvvATPase E significantly deterred feeding behavior and subsequently arrested the development of H.vigintioctopunctata.Notably,the bacterially expressed dsRNAs consistently caused higher mortality in larvae and adults.Finally,the nontarget effects of the dsRNAs of H.vigintioctopunctata on the predatory ladybeetle Propylaea japonica were evaluated.P.japonica 1st instar larvae were administered vATPase A and vATPase E dsRNAs from H.vigintioctopunctata and P.japonica under the worst-case scenario,in which dsGFP served as negative control.There were significant effects of dsHvvATPase A on P.japonica at the transcriptional level but not at the organismal level,whereas dsHvvATPase E did not effect P.japonica at either the transcriptional or the organismal level.Collectively,the results of the study suggest that HvvATPase A and HvvATPase E can act as novel molecular targets for the control of H.vigintioctopunctata.
基金supported by funding from the MaxPlanck Society (A.R.F.)the European Union’s Horizon 2020 research and innovation program, project PlantaSYST (Y.Z. and A.R.F.)
文摘The tricarboxylic acid(TCA) cycle is one of the canonical energy pathways of living systems, as well as being an example of a pathway in which dynamic enzyme assemblies, or metabolons, are well characterized. The role of the enzymes have been the subject of saturated transgenesis approaches, whereby the expression of the constituent enzymes were reduced or knocked out in order to ascertain their in vivo function.Some of the resultant plants exhibited improved photosynthesis and plant growth, under controlled greenhouse conditions. In addition, overexpression of the endogenous genes, or heterologous forms of a number of the enzymes, has been carried out in tomato fruit and the roots of a range of species, and in some instances improvement in fruit yield and postharvest properties and plant performance, under nutrient limitation, have been reported, respectively. Given a number of variants, in nature, we discuss possible synthetic approaches involving introducing these variants, or at least a subset of them, into plants. We additionally discuss the likely consequences of introducing synthetic metabolons, wherein certain pairs of reactions are artificially permanently assembled into plants, and speculate as to future strategies to further improve plant productivity by manipulation of the core metabolic pathway.
基金A.R.F.and Y.Z.thank the European Union's Horizon 2020 research and innovation program,project Planta SYST(SGA-CSA no.739582 under FPA no.664620)for supporting their research.
文摘Taxaceae is the yew family of conifers and includes evergreen trees and small shrubs mainly distributed in Eurasia and North America.The genus of Taxus has attracted considerable attention since Monroe E.Wall and Mansukh C.Wani firstly isolated and characterized an unusual cyclic diterpenoid from the bark of the Pacific yew tree(Wani et al.,1971).This compound,subsequently called paclitaxel,was shown to promote tubulin assembly into microtubules,preventing their disassembly.Subsequently,paclitaxel was approved for medical use against ovarian cancer in 1992(Fischer and Ganellin,2010).
基金supported by funding from the Max Planck Society(A.R.F.and Y.Z.)the European Union’s Horizon 2020 project PlantaSYST SGA-CSA no.739582 under FPA no.664620(A.R.F.and Y.Z.).
文摘Although the use of stable transformation technology has led to great insight into gene function,its application in high-throughput studies remains arduous.Agro-infiltration have been widely used in species such as Nicotiana benthamiana for the rapid detection of gene expression and protein interaction analysis,but this technique does not work efficiently in other plant species,including Arabidopsis thaliana.As an efficient high-throughput transient expression system is currently lacking in the model plant species A.thaliana,we developed a method that is characterized by high efficiency,reproducibility,and suitability for transient expression of a variety of functional proteins in A.thaliana and 7 other plant species,including Brassica oleracea,Capsella rubella,Thellungiella salsuginea,Thellungiella halophila,Solanum tuberosum,Capsicum annuum,and N.benthamiana.Efficiency of this method was independently verified in three independent research facilities,pointing to the robustness of this technique.Furthermore,in addition to demonstrating the utility of this technique in a range of species,we also present a case study employing this method to assess protein–protein interactions in the sucrose biosynthesis pathway in Arabidopsis.
基金This research was supported by the National Key R&D Program of China(2016YFD0200500)the National Natural Science Foundation of China(32072458)+1 种基金China Agriculture Research System of MOF and MARA(CARS-25)the Beijing Key Laboratory for Pest Control and Sustainable Cultivation of Vegetables,and the Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences(CAAS-ASTIP-IVFCAAS).
文摘The two-spotted spider mite Tetranychus urticate is an important agricultural pest worldwide.It is extremely polyphagous and has developed resistance to many pesticides.Here,we assessed the pesticide resistance of seven field populations of T.urticae in China,their target site mutations and the activities of their detoxification enzymes.The results showed that abamectin and the traditional pesticides pyridaben,profenofos and bifenthrin had higher resistance or lower toxicity than more recently developed pesticides including chlorfenapyr,spinetoram,cyflumetofen,cyenopyrafen,bifenazate and B-azolemiteacrylic.The frequency of point mutations related to abamectin resistance,G314D in the glutamate-gated chloride channel 1(GluCl1)and G326E in GluC13,ranged 47%-70%and 0%-97%,respectively.The frequency of point mutations in A1215D and F1538I of the voltage-gated sodium channel gene(VGSC),which may increase resistance to pyrethroids,ranged 88%-100%and 10%-100%,respectively.For target sites related to organophosphate resistance,mutation frequencies ranged 25%-92%for G119S and 0%-23%for A201S in the acetycholinesterase gene(Ace).Mutation G126S in the bifenazate resistance-related cytochrome b gene(Cytb)was observed in three of the seven T.urticae populations.Higher activities of detoxification enzymes(P450,GST,CarEs and UGTs)were observed in two T.urticae populations,with significant difference in the XY-SX population.These results provide useful information on the status of pesticide resistance of T.urticae in China and suggest that T.urticae field populations may have multiple resistance mechanisms.
基金Alisdair R.Fernie and Youjun Zhang would like to thank the European Union’s Horizon 2020 Research and Innovation Programme,project PlantaSYST(SGA-CSA no.739582 under FPA no.664620)for supporting their research on the metabolon.
文摘Despite species-specifc diferences in the pathways of respiratory metabolism are remarkably conserved across the kingdoms of life with glycolysis,the tricarboxylic acid cycle,and mitochondrial electron transport chain representing the major components of the process in the vast majority of organisms.In addition to being of critical importance in fueling life itself these pathways serve as interesting case studies for substrate channelling with research on this theme having been carried out for over 40 years.Here we provide a cross-kingdom review of the ample evidence for protein-protein interaction and enzyme assemblies within the three component pathways as well as describing the scarcer available evidence for substrate channelling itself.
基金supported by funding from the Max Planck Society(Y.Z.and A.R.F.)the European Union’s Horizon 2020 research and innovation programme,project PlantaSYST(SGA-CSA no.739582 under FPA no.664620)for supporting their research.
文摘Metabolons are transientmulti-protein complexes of sequential enzymes that mediate substrate channeling.They differ from multi-enzyme complexes in that they are dynamic,rather than permanent,and as such have considerably lower dissociation constants.Despite the fact that a huge number of metabolons have been suggested to exist in plants,most of these claims are erroneous as only a handful of these have been proven to channelmetabolites.We believe that physical protein-protein interactions between consecutive enzymes of a pathway should rather be called enzyme-enzyme assemblies.In this review,we describe how metabolons are generally assembled by transient interactions and held together by both structural elements and non-covalent interactions.Experimental evidence for their existence comes fromprotein-protein interaction studies,which indicate that the enzymes physically interact,and direct substrate channelingmeasurements,which indicate that they functionally interact.Unfortunately,advances in cell biology and proteomics have far outstripped those in classical enzymology and flux measurements,rendering most reports reliant purely on interactome studies.Recent developments in co-fractionation mass spectrometry will likely further exacerbate this bias.Given this,only dynamic enzyme-enzyme assemblies in which both physical and functional interactions have been demonstrated should be termed metabolons.We discuss the level of evidence for the manifold plant pathways that have been postulated to contain metabolons and then list examples in both primary and secondary metabolism for which strong evidence has been provided to support these claims.In doing so,we pay particular attention to experimental and mathematical approaches to study metabolons as well as complexities that arise in attempting to follow them.Finally,we discuss perspectives for improving our understanding of these fascinating but enigmatic interactions.
基金supported by the National Key Research and Development Program of China(2018YFD1000801)National Natural Science Foundation of China(32002050)the Science Technology Innovation Program of the Chinese Academy of Agricultural Sciences。
文摘Plant glandular trichomes are epidermal secretory structures that are important for plant resistance to pests.Although several regulatory genes have been characterized in trichome development,the molecular mechanisms conferring glandular trichome morphogenesis are unclear.We observed the differences in trichomes in cultivated tomato cv.‘Moneymaker’(MM) and the wild species Solanum pimpinellifolium PI365967 (PP),and used a recombinant inbred line (RIL) population to identify the genes that control trichome development in tomato.We found that the genomic variations in two genes,HAIR (H) and SPARSE HAIR (SH),contribute to the trichome differences between MM and PP.H and SH encode two paralogous C2H2 zinc-finger proteins that function redundantly in regulating trichome formation.Loss-offunction h/sh double mutants exhibited a significantly decreased number of Type I trichomes and complete loss of long stalk trichomes.Molecular and genetic analyses further indicate that H and SH act upstream of ZFP5.Overexpression of ZFP5 partially restored the trichome defects in NIL-h;sh;.Moreover,H and SH expression is induced by high temperatures,and their mutations inhibit the elongation of trichomes that reduce the plant repellent to whiteflies.Our findings confirm that H and SH are two vital transcription factors controlling initiation and elongation of Type I and III multicellular trichomes in tomato.