The globally exponential stability of nonlinear impul- sive networked control systems (NINCS) with time delay and packet dropouts is investigated. By applying Lyapunov function theory, sufficient conditions on the g...The globally exponential stability of nonlinear impul- sive networked control systems (NINCS) with time delay and packet dropouts is investigated. By applying Lyapunov function theory, sufficient conditions on the global exponential stability are derived by introducing a comparison system and estimating the corresponding Cauchy matrix. An impulsive controller is explicitly designed to achieve exponential stability and ensure state con- verge with a given decay rate for the system. The Lorenz oscillator system is presented as a numerical example to illustrate the theo- retical results and effectiveness of the proposed controller design procedure.展开更多
Trees in temperate regions exhibit evident seasonal patterns,which play vital roles in their growth and development.The activity of cambial stem cells is the basis for regulating the quantity and quality of wood,which...Trees in temperate regions exhibit evident seasonal patterns,which play vital roles in their growth and development.The activity of cambial stem cells is the basis for regulating the quantity and quality of wood,which has received considerable attention.However,the underlying mechanisms of these processes have not been fully elucidated.Here we performed a comprehensive analysis of morphological observations,transcriptome profiles,the DNA methylome,and miRNAs of the cambium in Populus tomentosa during the transition from dormancy to activation.Anatomical analysis showed that the active cambial zone exhibited a significant increase in the width and number of cell layers compared with those of the dormant and reactivating cambium.Furthermore,we found that differentially expressed genes associated with vascular development were mainly involved in plant hormone signal transduction,cell division and expansion,and cell wall biosynthesis.In addition,we identified 235 known miRNAs and 125 novel miRNAs.Differentially expressed miRNAs and target genes showed stronger negative correlations than other miRNA/target pairs.Moreover,global methylation and transcription analysis revealed that CG gene body methylation was positively correlated with gene expression,whereas CHG exhibited the opposite trend in the downstream region.Most importantly,we observed that the number of CHH differentially methylated region(DMR)changes was the greatest during cambium periodicity.Intriguingly,the genes with hypomethylated CHH DMRs in the promoter were involved in plant hormone signal transduction,phenylpropanoid biosynthesis,and plant–pathogen interactions during vascular cambium development.These findings improve our systems-level understanding of the epigenomic diversity that exists in the annual growth cycle of trees.展开更多
Reproduction is subtlety regulated by the hypothalamic-pituitary-gonad(HPG)axis in vertebrates.Pituitary gland is the center of the HPG axis,while pituitary gonadotropins follicle stimulating hormone(FSH)and luteinizi...Reproduction is subtlety regulated by the hypothalamic-pituitary-gonad(HPG)axis in vertebrates.Pituitary gland is the center of the HPG axis,while pituitary gonadotropins follicle stimulating hormone(FSH)and luteinizing hormone(LH)were identified the key elements of the HPG axis in teleost and mammal.Morphology,cell lines,and gonadotropins cell localization of female turbot and mouse pituitary were determined at mature stage to illustrate the anatomical difference and cell characteristics in this study.Results show that turbot pituitary is chicken heart-shaped,dorsoventral,located on the ventral surface of the diencephalon.The mouse pituitary is oval,located in the pituitary fossa of the sella turcica at the skull base.Two well-distinguished areas adenohypophysis(AH)and neurohypophysis(NH)in pituitary were identified in turbot and mouse.Turbot AH comprised the rostral pars distalis(RPD),proximal pars distalis(PPD),and pars intermedia(PI).NH was not pronounced and with finger-like protrusions into PPD.However,mouse AH only comprised the pars distalis(PD)and PI.NH distribution was semicircular.Three main types of cells(acidophilic,basophilic,and chromophobic cells)were distributed in the mouse PD region,whereas appeared in the turbot PPD,RPD,and PI.Moreover,the percentage of mouse chromophobic and basophilic cells was higher and lower than that of turbot,respectively.The diameter of the aforementioned three cells in the mouse was significantly higher than turbot.fshβ-and lhβ-immunoreactive signals were identified in turbot-distinct pituitary cells that primarily occupied the peripheral and central regions of AH.However,mouse fsh-and lh-immunoreactive cells were expressed in the same cells and present in the PD.These results demonstrate the significantly difference of pituitary morphology,cell lines and gonadotropins(fshβand lhβ)location in female turbot and mouse.These differences help for fully understand the evolution and endocrinological functions of pituitary.展开更多
Anatomical and chemical characteristics of stems affect lodging in wheat(Triticum aestivum L.) cultivars. Traits associated with lodging resistance, such as plant height, stem strength, culm wall thickness, pith diame...Anatomical and chemical characteristics of stems affect lodging in wheat(Triticum aestivum L.) cultivars. Traits associated with lodging resistance, such as plant height, stem strength, culm wall thickness, pith diameter, and stem diameter, were extensively investigated in earlier studies. However, the solid stem trait was rarely considered. In this study, we measured a range of anatomical and chemical characteristics on solid and hollow stemmed wheat cultivars. Significant correlations were detected between resistance to lodging and several anatomical features, including width of mechanical tissue, weight of low internodes, and width of stem walls. Morphological features that gave the best indication of improved lodging resistance were increased stem width, width of mechanical tissue layer, and stem density. Multiple linear regression analysis showed that 99% of the variation in lodging resistance could be explained by the width of the mechanical tissue layer, suggesting that solid stemmed wheat has several anatomical features for increasing resistance to lodging. In addition, microsatellite markers GWM247 and GWM340 were linked to a single solid stem QTL on chromosome 3BL in a population derived from the cross Xinongshixin(solid stem)/Line 3159(hollow stem). These markers should be valuable in breeding wheat for solid stem.展开更多
Anthocyanins biosynthesized from the flavonoid pathway are types of pigments that are involved in the protection of poplar from biotic and abiotic stresses.Previous researchers studying anthocyanin-related transcripti...Anthocyanins biosynthesized from the flavonoid pathway are types of pigments that are involved in the protection of poplar from biotic and abiotic stresses.Previous researchers studying anthocyanin-related transcription factors and structural genes in poplar have made significant discoveries.However,little is known about the regulatory role of microRNAs in anthocyanin biosynthesis in poplar.Here,we overexpressed miR156 in poplar to study the comprehensive effects of the miR156-SPL module on the biosynthesis of anthocyanins.Small RNA sequencing analysis revealed 228 microRNAs differentially expressed in transgenic poplar plants with dramatically increased miR156 levels.Furthermore,integrated microRNAomic and transcriptomic analysis suggested that two microRNAs,miR160h,and miR858,have the potential to affect anthocyanin accumulation in poplar by regulating auxin response factors and MYB transcription factors,respectively.Additionally,the accumulation of miR160h and miR858 displayed a positive correlation with miR156 levels,suggesting a possible interaction between the miR156-SPL module and these microRNAs in poplar.Last,metabolomics analysis revealed that the levels of anthocyanins,flavones,and flavonols were substantially elevated in transgenic poplar plants overexpressing miR156 compared with the wild type,whereas the total lignin content was reduced in the transgenic plants.Taken together,our results indicate that miR156 can fine tune the anthocyanin biosynthetic pathway via multiple factors,including microRNAs,transcription factors,and the levels of structural genes,in poplar.This provides additional clues for understanding the complex regulatory network of anthocyanin biosynthesis in woody plants.展开更多
The problems of robust stability and stabilization via memoryless state feedback for a class of discrete-time switched singular systems with time-varying delays and linear fractional uncertainties are investigated.By ...The problems of robust stability and stabilization via memoryless state feedback for a class of discrete-time switched singular systems with time-varying delays and linear fractional uncertainties are investigated.By constructing a novel switched Lyapunov-Krasovskii functional,a delay-dependent criterion for the unforced system to be regular,causal and uniformly asymptotically stable is established in terms of linear matrix inequalities(LMIs).An explicit expression for the desired memoryless state feedback stabilization controller is also given.The merits of the proposed criteria lie in their less conservativeness and relative simplicity,which are achieved by considering additionally useful terms(ignored in previous methods) when estimating the upper bound of the forward difference of the Lyapunov-Krasovskii functional and by avoiding utilizing any model augmentation transformation.Some numerical examples are provided to illustrate the validity of the proposed methods.展开更多
In this study,rice straw(RS) was liquefied by ethylene carbonate(EC) using H_2SO_4 as a catalyst.The effects of various process conditions on the liquefaction characteristics were investigated by FT-IR and residue con...In this study,rice straw(RS) was liquefied by ethylene carbonate(EC) using H_2SO_4 as a catalyst.The effects of various process conditions on the liquefaction characteristics were investigated by FT-IR and residue content analysis.The results show that cellulose and lignin are degraded during the liquefaction process and large amounts of groups are generated.In addition,it is difficult to effectively liquefy RS by using EC alone as the liquefying agent without other additives.Compared to water addition on liquefaction,the residue content can be significantly reduced up to 30% by adding H_2O_2.It has also been proved that the liquor ratio(RS/EC,w/v) of 1∶5 with H_2O_2 as an additive at 145℃ for liquefaction time of 60 min in the presence of H_2SO_4 can accelerate the liquefaction process and high liquefaction yield can be obtained.展开更多
Dear Editor,Plant cell walls are complex and dynamic structures that are mainly composed of polysaccharide polymers such as cellulose,hemicellulose,and pectin,in addition to substantial amounts of the non-saccharide p...Dear Editor,Plant cell walls are complex and dynamic structures that are mainly composed of polysaccharide polymers such as cellulose,hemicellulose,and pectin,in addition to substantial amounts of the non-saccharide polymer lignin(McFarlane et al.,2014;German et al.,2023).The components of cell walls are interconnected in various ways to form a complex,multilayered network structure(Wen et al.,2023).展开更多
The plant cytoskeleton undergoes dynamic remodeling in response to diverse developmental and environmental cues. Remodeling of the cytoskeleton coordinates growth in plant cells, including trafficking and exocytosis o...The plant cytoskeleton undergoes dynamic remodeling in response to diverse developmental and environmental cues. Remodeling of the cytoskeleton coordinates growth in plant cells, including trafficking and exocytosis of membrane and wall components during cell expansion, and regulation of hypocotyl elongation in response to light. Cytoskeletal remodeling also has key functions in disease resistance and abiotic stress responses. Many stimuli result in altered activity of cytoskeleton-associatedproteins,microtubuleassociated proteins(MAPs) and actin-binding proteins(ABPs). MAPs and ABPs are the main players determining the spatiotemporally dynamic nature of the cytoskeleton, functioning in a sensory hub that decodes signals to modulate plant cytoskeletal behavior. Moreover, MAP and ABP activities and levels are precisely regulated during development and environmental responses, but our understanding of this process remains limited. In this review, we summarize the evidence linking multiple signaling pathways, MAP and ABP activities and levels, and cytoskeletal rearrangements in plant cells. We highlight advances in elucidating the multiple mechanisms that regulate MAP and ABP activities and levels, including calcium and calmodulin signaling, ROP GTPase activity, phospholipid signaling, and post-translational modifications.展开更多
The plant cell wall is an important interface for sensing pathogen attack and activating signaling pathways that promote plant immune responses.THESEUS1(THE1) acts as a sensor of cell wall integrity that controls cell...The plant cell wall is an important interface for sensing pathogen attack and activating signaling pathways that promote plant immune responses.THESEUS1(THE1) acts as a sensor of cell wall integrity that controls cell elongation during plant growth.However, no specific role for THE1 in plant defense responses has been reported. Here, we found that THE1 interacts with GUANINE EXCHANGE FACTOR4(GEF4)and that both proteins play regulatory roles in plant resistance to the necrotrophic fungus Botrytis cinerea.Genetic analysis showed that THE1 and GEF4 function in the same genetic pathway to mediate plant defense responses. In addition, using transcriptome analysis, we identified various genes(such as defense-related,secondary metabolite-related, and transcription factor genes) that are likely downstream targets in the THE1-GEF4 signaling pathway. Our results suggest that THE1 functions as an upstream regulator of GEF4 signaling to positively regulate defense responses against B. cinerea in Arabidopsis.展开更多
Proanthocyanidins(PAs)are natural flavan-3-ol polymers that contribute protection to plants under biotic and abiotic stress,benefits to human health,and bitterness and astringency to food products.They are also potent...Proanthocyanidins(PAs)are natural flavan-3-ol polymers that contribute protection to plants under biotic and abiotic stress,benefits to human health,and bitterness and astringency to food products.They are also potential targets for carbon sequestration for climate mitigation.In recent years,from model species to commercial crops,research has moved closer to elucidating the flux control and channeling,subunit biosynthesis and polymerization,transport mechanisms,and regulatory networks involved in plant PA metabolism.This review extends the conventional understanding with recent findings that provide new insights to address lingering questions and focus strategies for manipulating PA traits in plants.展开更多
The major brassinosteroid (BR) receptor of Arabidopsis BRASSINOSTEROID INSENSITIVE1 (BRI1) plays fundamental roles in BR signaling, but the molecular mechanisms underlying the effects of BR on BRI1 internalization...The major brassinosteroid (BR) receptor of Arabidopsis BRASSINOSTEROID INSENSITIVE1 (BRI1) plays fundamental roles in BR signaling, but the molecular mechanisms underlying the effects of BR on BRI1 internalization and assembly state remain unclear. Here, we applied variable angle total internal reflection fluorescence microscopy and fluorescence cross-correlation spectroscopy to analyze the dynamics of GFP-tagged BRII. We found that, in response to BR, the degree of co-localization of BRI1-GFP with AtFIotl-mCherry increased, and especially BR stimulated the membrane microdomain-associated pathway of BRI1 internalization. We also verified these observations in endocytosis-defective chc2-1 mutants and the AtFIotl amiRNA 15-5 lines. Furthermore, examination of the phosphorylation status of bril-EMS-suppressor 1 and measurement of BR-responsive gene expression revealed that membrane microdomains affect BR signaling. These results suggest that BR promotes the partitioning of BRI1 into functional membrane microdomains to activate BR signaling.展开更多
Detecting protein-protein interactions(PPIs) provides fundamental information for understanding biochemical processes such as the transduction of signals from one cellular location to another; however, traditional bio...Detecting protein-protein interactions(PPIs) provides fundamental information for understanding biochemical processes such as the transduction of signals from one cellular location to another; however, traditional biochemical techniques cannot provide sufficient spatio-temporal information to elucidate these molecular interactions in living cells. Over the past decade, several new techniques have enabled the identification and characterization of PPIs. In this review, we summarize three main techniques for detecting PPIs in vivo, focusing on their basic principles and applications in biological studies. We place a special emphasis on their advantages and limitations, and, in particular, we introduced some uncommon new techniques, such as single-molecule FRET(smFRET), FRET-fluorescence lifetime imaging microscopy(FRET-FLIM), cytoskeleton-based assay for protein-protein interaction(CAPPI) and single-molecule protein proximity index(smPPI), highlighting recent improvements to the established techniques. We hope that this review will provide a valuable reference to enable researchers to select the most appropriate technique for detecting PPIs.展开更多
Formin is a major protein responsible for regulating the nucleation of actin filaments, and as such, it permits the cell to control where and when to assemble actin arrays. It is encoded by a multigene family comprisi...Formin is a major protein responsible for regulating the nucleation of actin filaments, and as such, it permits the cell to control where and when to assemble actin arrays. It is encoded by a multigene family comprising 21 members in Arabidopsis thaliana. The Arabidopsis formins can be separated into two phylogenetically-distinct classes: there are 11 class I formins and 10 class II formins. Significant questions remain unanswered regarding the molecular mechanism of actin nucleation and elongation stimulated by each formin isovariant, and how the different isovariants coordinate to regulate actin dynamics in cells. Here, we characterize a class II formin, AtFH19, biochemically. We found that AtFH19 retains all general properties of the formin family, including nucleation and barbed end capping activity. It can also generate actin filaments from a pool of actin monomers bound to profilin. However, both the nucleation and barbed end capping activities of AtFH19 are less efficient compared to those of another well-characterized formin, AtFHI. Interestingly, AtFH19 FH1FH2 competes with AtFH1 FHIFH2 in binding actin filament barbed ends, and inhibits the effect of AtFH1 FHIFH2 on actin. We thus propose a mechanism in which two quantitatively different formins coordinate to regulate actin dynamics by competing for actin filament barbed ends.展开更多
In multicellular and even single-celled organisms,individual components are interconnected at multiscale levels to produce enormously complex biological networks that help these systems maintain homeostasis for develo...In multicellular and even single-celled organisms,individual components are interconnected at multiscale levels to produce enormously complex biological networks that help these systems maintain homeostasis for development and environmental adaptation.Systems biology studies initially adopted network analysis to explore how relationships between individual components give rise to complex biological processes.Network analysis has been applied to dissect the complex connectivity of mammalian brains across different scales in time and space in The Human Brain Project.In plant science,network analysis has similarly been applied to study the connectivity of plant components at the molecular,subcellular,cellular,organic,and organism levels.Analysis of these multiscale networks contributes to our understanding of how genotype determines phenotype.In this review,we summarized the theoretical framework of plant multiscale networks and introduced studies investigating plant networks by various experimental and computational modalities.We next discussed the currently available analytic methodologies and multi-level imaging techniques used to map multiscale networks in plants.Finally,we highlighted some of the technical challenges and key questions remaining to be addressed in this emerging field.展开更多
The plasma membrane is a sophisticated,organized,and highly heterogeneous structure that compartmentalizes cellular processes.To decipher the biological processes involving membrane proteins,it is necessary to analyze...The plasma membrane is a sophisticated,organized,and highly heterogeneous structure that compartmentalizes cellular processes.To decipher the biological processes involving membrane proteins,it is necessary to analyze their spatiotemporal dynamics.However,it is difficult to directly assess the dynamics and interactions of biomolecules in living cells using traditional biochemical methods.Singleparticle tracking (SPT)methods for imaging and tracking single particles conjugated with fluorescent probes offer an ideal approach to acquire valuable and complementary information about dynamic intracellular processes.SPT can be used to quantitatively monitor the diverse motions of individual particles in living cells.SPT also provides super-spatiotemporal resolution that allows early-stage or rapid response information to be obtained for a better understanding of molecular basis of associated signal transduction processes.More importantly,SPT can be used to detect the motion paths of individual biomolecules in vivo and in situ,thus unveiling the dynamic behavior of the biomolecules that support developmental processes in living cells.In this review,we give an overview of SPT methods,from image acquisition to the detection of single particles,as well as tracking and data analysis.We also discuss recent applications of SPT methods in the field ofplant biology to reveal the complex biological functions of membrane proteins.展开更多
Phototropin (phot)-mediated signaling initiated by blue light (BL) plays a critical role in optimizing photosyn- thetic light capture at the plasma membrane (PM) in plants. However, the mechanisms underlying the...Phototropin (phot)-mediated signaling initiated by blue light (BL) plays a critical role in optimizing photosyn- thetic light capture at the plasma membrane (PM) in plants. However, the mechanisms underlying the regu- lation of phot activity at the PM in response to BL remain largely unclear. In this study, by single-particle tracking and stepwise photobleaching analysis of photl-GFP proteins we demonstrated that in the dark photl proteins remain in an inactive state and mostly exist as monomers. Dimerization and the diffusion rate of photl-GFP increased in a dose-dependent manner in response to BL. In contrast, BL did not affect the lateral diffusion of kinase-inactive photlD806N-GFP but did enhance its dimerization, suggesting that photl dimerization is independent of phosphorylation. Forster resonance energy transfer-fluorescence life- time imaging microscopy analysis revealed that the interaction between photl-GFP and a marker of sterol- rich lipid environments, AtRem1.3-mCherry, was enhanced with increased time of BL treatment. However, this BL-dependent interaction was not obvious in plants co-expressing phot1D806N-GFP and AtRem1.3- mCherry, indicating that BL facilitates the translocation of functional photl-GFP into AtRem1.3-1abeled microdomains to activate phot-mediated signaling. Conversely, sterol depletion attenuated photl-GFP dynamics, dimerization, and phosphorylation. Taken together, these results indicate that membrane micro- domains act as organizing platforms essential for the proper function of activated photl at the PM.展开更多
基金supported by the National Natural Science Foundation of China (6090402060574006)the Research Fund for the Doctoral Program of Higher Eolucation of China (20070286039)
文摘The globally exponential stability of nonlinear impul- sive networked control systems (NINCS) with time delay and packet dropouts is investigated. By applying Lyapunov function theory, sufficient conditions on the global exponential stability are derived by introducing a comparison system and estimating the corresponding Cauchy matrix. An impulsive controller is explicitly designed to achieve exponential stability and ensure state con- verge with a given decay rate for the system. The Lorenz oscillator system is presented as a numerical example to illustrate the theo- retical results and effectiveness of the proposed controller design procedure.
基金the State“13.5”Key Research Program of China(2016YFD0600102)the National Natural Science Foundation of China(31761133009,31970182,31670182,31800504,31970653,and 32000483)+2 种基金the Fundamental Research Funds for the Central Universities(2019ZY29 and 2017ZY10)Beijing Forestry University Outstanding Young Talent Cultivation Project(2019JQ03003)the Program of Introducing Talents of Discipline to Universities(111 project,B13007).
文摘Trees in temperate regions exhibit evident seasonal patterns,which play vital roles in their growth and development.The activity of cambial stem cells is the basis for regulating the quantity and quality of wood,which has received considerable attention.However,the underlying mechanisms of these processes have not been fully elucidated.Here we performed a comprehensive analysis of morphological observations,transcriptome profiles,the DNA methylome,and miRNAs of the cambium in Populus tomentosa during the transition from dormancy to activation.Anatomical analysis showed that the active cambial zone exhibited a significant increase in the width and number of cell layers compared with those of the dormant and reactivating cambium.Furthermore,we found that differentially expressed genes associated with vascular development were mainly involved in plant hormone signal transduction,cell division and expansion,and cell wall biosynthesis.In addition,we identified 235 known miRNAs and 125 novel miRNAs.Differentially expressed miRNAs and target genes showed stronger negative correlations than other miRNA/target pairs.Moreover,global methylation and transcription analysis revealed that CG gene body methylation was positively correlated with gene expression,whereas CHG exhibited the opposite trend in the downstream region.Most importantly,we observed that the number of CHH differentially methylated region(DMR)changes was the greatest during cambium periodicity.Intriguingly,the genes with hypomethylated CHH DMRs in the promoter were involved in plant hormone signal transduction,phenylpropanoid biosynthesis,and plant–pathogen interactions during vascular cambium development.These findings improve our systems-level understanding of the epigenomic diversity that exists in the annual growth cycle of trees.
基金Supported by the National Natural Science Foundation of China(No.31972811)the Special Fund for Basic Scientific Research of Central Public Research Institutes(No.2020T51)。
文摘Reproduction is subtlety regulated by the hypothalamic-pituitary-gonad(HPG)axis in vertebrates.Pituitary gland is the center of the HPG axis,while pituitary gonadotropins follicle stimulating hormone(FSH)and luteinizing hormone(LH)were identified the key elements of the HPG axis in teleost and mammal.Morphology,cell lines,and gonadotropins cell localization of female turbot and mouse pituitary were determined at mature stage to illustrate the anatomical difference and cell characteristics in this study.Results show that turbot pituitary is chicken heart-shaped,dorsoventral,located on the ventral surface of the diencephalon.The mouse pituitary is oval,located in the pituitary fossa of the sella turcica at the skull base.Two well-distinguished areas adenohypophysis(AH)and neurohypophysis(NH)in pituitary were identified in turbot and mouse.Turbot AH comprised the rostral pars distalis(RPD),proximal pars distalis(PPD),and pars intermedia(PI).NH was not pronounced and with finger-like protrusions into PPD.However,mouse AH only comprised the pars distalis(PD)and PI.NH distribution was semicircular.Three main types of cells(acidophilic,basophilic,and chromophobic cells)were distributed in the mouse PD region,whereas appeared in the turbot PPD,RPD,and PI.Moreover,the percentage of mouse chromophobic and basophilic cells was higher and lower than that of turbot,respectively.The diameter of the aforementioned three cells in the mouse was significantly higher than turbot.fshβ-and lhβ-immunoreactive signals were identified in turbot-distinct pituitary cells that primarily occupied the peripheral and central regions of AH.However,mouse fsh-and lh-immunoreactive cells were expressed in the same cells and present in the PD.These results demonstrate the significantly difference of pituitary morphology,cell lines and gonadotropins(fshβand lhβ)location in female turbot and mouse.These differences help for fully understand the evolution and endocrinological functions of pituitary.
基金supported by the National Basic Research Program of China (2011CB100302)the Knowledge Innovation Program of CAS (KSCX2-EW-N-02)
文摘Anatomical and chemical characteristics of stems affect lodging in wheat(Triticum aestivum L.) cultivars. Traits associated with lodging resistance, such as plant height, stem strength, culm wall thickness, pith diameter, and stem diameter, were extensively investigated in earlier studies. However, the solid stem trait was rarely considered. In this study, we measured a range of anatomical and chemical characteristics on solid and hollow stemmed wheat cultivars. Significant correlations were detected between resistance to lodging and several anatomical features, including width of mechanical tissue, weight of low internodes, and width of stem walls. Morphological features that gave the best indication of improved lodging resistance were increased stem width, width of mechanical tissue layer, and stem density. Multiple linear regression analysis showed that 99% of the variation in lodging resistance could be explained by the width of the mechanical tissue layer, suggesting that solid stemmed wheat has several anatomical features for increasing resistance to lodging. In addition, microsatellite markers GWM247 and GWM340 were linked to a single solid stem QTL on chromosome 3BL in a population derived from the cross Xinongshixin(solid stem)/Line 3159(hollow stem). These markers should be valuable in breeding wheat for solid stem.
基金supported by the National Key Program on Transgenic Research of China(No.2018ZX08021001-005-001)the National Natural Science Foundation of China(Nos.31672479,31701496,and 31801429)+1 种基金the Major Program of Shandong Province Natural Science Foundation(No.ZR2018ZB0213)the Assisted Project by Heilong Jiang Postdoctoral Funds for Scientific Research Initiation(LBH-Z18262).
文摘Anthocyanins biosynthesized from the flavonoid pathway are types of pigments that are involved in the protection of poplar from biotic and abiotic stresses.Previous researchers studying anthocyanin-related transcription factors and structural genes in poplar have made significant discoveries.However,little is known about the regulatory role of microRNAs in anthocyanin biosynthesis in poplar.Here,we overexpressed miR156 in poplar to study the comprehensive effects of the miR156-SPL module on the biosynthesis of anthocyanins.Small RNA sequencing analysis revealed 228 microRNAs differentially expressed in transgenic poplar plants with dramatically increased miR156 levels.Furthermore,integrated microRNAomic and transcriptomic analysis suggested that two microRNAs,miR160h,and miR858,have the potential to affect anthocyanin accumulation in poplar by regulating auxin response factors and MYB transcription factors,respectively.Additionally,the accumulation of miR160h and miR858 displayed a positive correlation with miR156 levels,suggesting a possible interaction between the miR156-SPL module and these microRNAs in poplar.Last,metabolomics analysis revealed that the levels of anthocyanins,flavones,and flavonols were substantially elevated in transgenic poplar plants overexpressing miR156 compared with the wild type,whereas the total lignin content was reduced in the transgenic plants.Taken together,our results indicate that miR156 can fine tune the anthocyanin biosynthetic pathway via multiple factors,including microRNAs,transcription factors,and the levels of structural genes,in poplar.This provides additional clues for understanding the complex regulatory network of anthocyanin biosynthesis in woody plants.
基金supported by the National Natural Science Foundation of China(6090402060835001)the Jiangsu Planned Projects for Postdoctoral Research Funds(0802010C)
文摘The problems of robust stability and stabilization via memoryless state feedback for a class of discrete-time switched singular systems with time-varying delays and linear fractional uncertainties are investigated.By constructing a novel switched Lyapunov-Krasovskii functional,a delay-dependent criterion for the unforced system to be regular,causal and uniformly asymptotically stable is established in terms of linear matrix inequalities(LMIs).An explicit expression for the desired memoryless state feedback stabilization controller is also given.The merits of the proposed criteria lie in their less conservativeness and relative simplicity,which are achieved by considering additionally useful terms(ignored in previous methods) when estimating the upper bound of the forward difference of the Lyapunov-Krasovskii functional and by avoiding utilizing any model augmentation transformation.Some numerical examples are provided to illustrate the validity of the proposed methods.
基金supported by the National Natural Science Foundation of China(31270633)State Key Laboratory of Pulp and Paper Engineering(201512)Hangzhou Qianjiang Distinguished Experts Programme of China
文摘In this study,rice straw(RS) was liquefied by ethylene carbonate(EC) using H_2SO_4 as a catalyst.The effects of various process conditions on the liquefaction characteristics were investigated by FT-IR and residue content analysis.The results show that cellulose and lignin are degraded during the liquefaction process and large amounts of groups are generated.In addition,it is difficult to effectively liquefy RS by using EC alone as the liquefying agent without other additives.Compared to water addition on liquefaction,the residue content can be significantly reduced up to 30% by adding H_2O_2.It has also been proved that the liquor ratio(RS/EC,w/v) of 1∶5 with H_2O_2 as an additive at 145℃ for liquefaction time of 60 min in the presence of H_2SO_4 can accelerate the liquefaction process and high liquefaction yield can be obtained.
基金supported by the National Natural Science Foundation of China(32030010,32000558,32370740)Fundamental Research Funds for the Central Universities(BLX202116 and QNTD202301)+4 种基金Engineering Research&Innovation Team Project of Beijing Forestry University(NBLRC2023C06)Beijing Forestry University Outstanding Postgraduate Mentoring Team Building(YJSYDSTD2022005)Beijing Municipal Natural Science Foundation(5232016),Beijing Nova Program(20230484251)Ministry of Science and Technology High-end Foreign Experts Introduction Program(G2022109007L)the Project Funded by China Postdoctoral Science Foundation(2022T150054,2023T160054).
文摘Dear Editor,Plant cell walls are complex and dynamic structures that are mainly composed of polysaccharide polymers such as cellulose,hemicellulose,and pectin,in addition to substantial amounts of the non-saccharide polymer lignin(McFarlane et al.,2014;German et al.,2023).The components of cell walls are interconnected in various ways to form a complex,multilayered network structure(Wen et al.,2023).
基金supported by the National Natural Science Foundation of China(31771493, 32030010)the Program of Introducing Talents of Discipline to Universities (111 Project, B13007)the China Postdoctoral Science Foundation (2018M641219,2019T120057)。
文摘The plant cytoskeleton undergoes dynamic remodeling in response to diverse developmental and environmental cues. Remodeling of the cytoskeleton coordinates growth in plant cells, including trafficking and exocytosis of membrane and wall components during cell expansion, and regulation of hypocotyl elongation in response to light. Cytoskeletal remodeling also has key functions in disease resistance and abiotic stress responses. Many stimuli result in altered activity of cytoskeleton-associatedproteins,microtubuleassociated proteins(MAPs) and actin-binding proteins(ABPs). MAPs and ABPs are the main players determining the spatiotemporally dynamic nature of the cytoskeleton, functioning in a sensory hub that decodes signals to modulate plant cytoskeletal behavior. Moreover, MAP and ABP activities and levels are precisely regulated during development and environmental responses, but our understanding of this process remains limited. In this review, we summarize the evidence linking multiple signaling pathways, MAP and ABP activities and levels, and cytoskeletal rearrangements in plant cells. We highlight advances in elucidating the multiple mechanisms that regulate MAP and ABP activities and levels, including calcium and calmodulin signaling, ROP GTPase activity, phospholipid signaling, and post-translational modifications.
基金supported by the National Natural Science Foundation of China(31400221)the Beijing Advanced Innovation Center for Tree Breeding by Molecular Design+1 种基金the Program for Changjiang Scholars and Innovative Research Team in University(IRT13047)the Fundamental Research Funds for the Central Universities(BLX2012038)
文摘The plant cell wall is an important interface for sensing pathogen attack and activating signaling pathways that promote plant immune responses.THESEUS1(THE1) acts as a sensor of cell wall integrity that controls cell elongation during plant growth.However, no specific role for THE1 in plant defense responses has been reported. Here, we found that THE1 interacts with GUANINE EXCHANGE FACTOR4(GEF4)and that both proteins play regulatory roles in plant resistance to the necrotrophic fungus Botrytis cinerea.Genetic analysis showed that THE1 and GEF4 function in the same genetic pathway to mediate plant defense responses. In addition, using transcriptome analysis, we identified various genes(such as defense-related,secondary metabolite-related, and transcription factor genes) that are likely downstream targets in the THE1-GEF4 signaling pathway. Our results suggest that THE1 functions as an upstream regulator of GEF4 signaling to positively regulate defense responses against B. cinerea in Arabidopsis.
基金supported by the Program of Introducing Talents of Discipline to Universities(111 Project,B13007)the National Natural Science Foundation of China(32030010)the China Postdoctoral Science Foundation(2020M680404 to K.Y.).
文摘Proanthocyanidins(PAs)are natural flavan-3-ol polymers that contribute protection to plants under biotic and abiotic stress,benefits to human health,and bitterness and astringency to food products.They are also potential targets for carbon sequestration for climate mitigation.In recent years,from model species to commercial crops,research has moved closer to elucidating the flux control and channeling,subunit biosynthesis and polymerization,transport mechanisms,and regulatory networks involved in plant PA metabolism.This review extends the conventional understanding with recent findings that provide new insights to address lingering questions and focus strategies for manipulating PA traits in plants.
文摘The major brassinosteroid (BR) receptor of Arabidopsis BRASSINOSTEROID INSENSITIVE1 (BRI1) plays fundamental roles in BR signaling, but the molecular mechanisms underlying the effects of BR on BRI1 internalization and assembly state remain unclear. Here, we applied variable angle total internal reflection fluorescence microscopy and fluorescence cross-correlation spectroscopy to analyze the dynamics of GFP-tagged BRII. We found that, in response to BR, the degree of co-localization of BRI1-GFP with AtFIotl-mCherry increased, and especially BR stimulated the membrane microdomain-associated pathway of BRI1 internalization. We also verified these observations in endocytosis-defective chc2-1 mutants and the AtFIotl amiRNA 15-5 lines. Furthermore, examination of the phosphorylation status of bril-EMS-suppressor 1 and measurement of BR-responsive gene expression revealed that membrane microdomains affect BR signaling. These results suggest that BR promotes the partitioning of BRI1 into functional membrane microdomains to activate BR signaling.
基金supported by the National Natural Science Foundation of China(31530084,31761133009)the Programme of Introducing Talents of Discipline to Universities(111 project,B13007)
文摘Detecting protein-protein interactions(PPIs) provides fundamental information for understanding biochemical processes such as the transduction of signals from one cellular location to another; however, traditional biochemical techniques cannot provide sufficient spatio-temporal information to elucidate these molecular interactions in living cells. Over the past decade, several new techniques have enabled the identification and characterization of PPIs. In this review, we summarize three main techniques for detecting PPIs in vivo, focusing on their basic principles and applications in biological studies. We place a special emphasis on their advantages and limitations, and, in particular, we introduced some uncommon new techniques, such as single-molecule FRET(smFRET), FRET-fluorescence lifetime imaging microscopy(FRET-FLIM), cytoskeleton-based assay for protein-protein interaction(CAPPI) and single-molecule protein proximity index(smPPI), highlighting recent improvements to the established techniques. We hope that this review will provide a valuable reference to enable researchers to select the most appropriate technique for detecting PPIs.
基金supported by the China National Fund for Distinguished Young Scholars(31125004)partially supported by the CAS/SAFEA International Partnership Program for Creative Research Teams and SRF for ROCS,SEM
文摘Formin is a major protein responsible for regulating the nucleation of actin filaments, and as such, it permits the cell to control where and when to assemble actin arrays. It is encoded by a multigene family comprising 21 members in Arabidopsis thaliana. The Arabidopsis formins can be separated into two phylogenetically-distinct classes: there are 11 class I formins and 10 class II formins. Significant questions remain unanswered regarding the molecular mechanism of actin nucleation and elongation stimulated by each formin isovariant, and how the different isovariants coordinate to regulate actin dynamics in cells. Here, we characterize a class II formin, AtFH19, biochemically. We found that AtFH19 retains all general properties of the formin family, including nucleation and barbed end capping activity. It can also generate actin filaments from a pool of actin monomers bound to profilin. However, both the nucleation and barbed end capping activities of AtFH19 are less efficient compared to those of another well-characterized formin, AtFHI. Interestingly, AtFH19 FH1FH2 competes with AtFH1 FHIFH2 in binding actin filament barbed ends, and inhibits the effect of AtFH1 FHIFH2 on actin. We thus propose a mechanism in which two quantitatively different formins coordinate to regulate actin dynamics by competing for actin filament barbed ends.
基金supported by the National Natural Science Foundation of China(31530084,32000558,32000483,and31800504)the Programme of Introducing Talents of Discipline to Universities(111 project,B13007)the China Postdoctoral Science Foundation Grant(2019M660494)。
文摘In multicellular and even single-celled organisms,individual components are interconnected at multiscale levels to produce enormously complex biological networks that help these systems maintain homeostasis for development and environmental adaptation.Systems biology studies initially adopted network analysis to explore how relationships between individual components give rise to complex biological processes.Network analysis has been applied to dissect the complex connectivity of mammalian brains across different scales in time and space in The Human Brain Project.In plant science,network analysis has similarly been applied to study the connectivity of plant components at the molecular,subcellular,cellular,organic,and organism levels.Analysis of these multiscale networks contributes to our understanding of how genotype determines phenotype.In this review,we summarized the theoretical framework of plant multiscale networks and introduced studies investigating plant networks by various experimental and computational modalities.We next discussed the currently available analytic methodologies and multi-level imaging techniques used to map multiscale networks in plants.Finally,we highlighted some of the technical challenges and key questions remaining to be addressed in this emerging field.
基金the National Natural Science Foundation of China (31622005,31530084) the Programme of Introducing Talents of Discipline to Universities (111project,B13007).
文摘The plasma membrane is a sophisticated,organized,and highly heterogeneous structure that compartmentalizes cellular processes.To decipher the biological processes involving membrane proteins,it is necessary to analyze their spatiotemporal dynamics.However,it is difficult to directly assess the dynamics and interactions of biomolecules in living cells using traditional biochemical methods.Singleparticle tracking (SPT)methods for imaging and tracking single particles conjugated with fluorescent probes offer an ideal approach to acquire valuable and complementary information about dynamic intracellular processes.SPT can be used to quantitatively monitor the diverse motions of individual particles in living cells.SPT also provides super-spatiotemporal resolution that allows early-stage or rapid response information to be obtained for a better understanding of molecular basis of associated signal transduction processes.More importantly,SPT can be used to detect the motion paths of individual biomolecules in vivo and in situ,thus unveiling the dynamic behavior of the biomolecules that support developmental processes in living cells.In this review,we give an overview of SPT methods,from image acquisition to the detection of single particles,as well as tracking and data analysis.We also discuss recent applications of SPT methods in the field ofplant biology to reveal the complex biological functions of membrane proteins.
基金This work is supported by the National Natural Science Foundation of China (31530084, 31270224) and the Program of Introducing Talents of Discipline to Universities (111 project, B13007).
文摘Phototropin (phot)-mediated signaling initiated by blue light (BL) plays a critical role in optimizing photosyn- thetic light capture at the plasma membrane (PM) in plants. However, the mechanisms underlying the regu- lation of phot activity at the PM in response to BL remain largely unclear. In this study, by single-particle tracking and stepwise photobleaching analysis of photl-GFP proteins we demonstrated that in the dark photl proteins remain in an inactive state and mostly exist as monomers. Dimerization and the diffusion rate of photl-GFP increased in a dose-dependent manner in response to BL. In contrast, BL did not affect the lateral diffusion of kinase-inactive photlD806N-GFP but did enhance its dimerization, suggesting that photl dimerization is independent of phosphorylation. Forster resonance energy transfer-fluorescence life- time imaging microscopy analysis revealed that the interaction between photl-GFP and a marker of sterol- rich lipid environments, AtRem1.3-mCherry, was enhanced with increased time of BL treatment. However, this BL-dependent interaction was not obvious in plants co-expressing phot1D806N-GFP and AtRem1.3- mCherry, indicating that BL facilitates the translocation of functional photl-GFP into AtRem1.3-1abeled microdomains to activate phot-mediated signaling. Conversely, sterol depletion attenuated photl-GFP dynamics, dimerization, and phosphorylation. Taken together, these results indicate that membrane micro- domains act as organizing platforms essential for the proper function of activated photl at the PM.