Seed viability is an essential feature for genetic resource conservation as well as sustainable crop production.Long-term storage induces seed viability deterioration or seed aging,accompanied by the accumulation of t...Seed viability is an essential feature for genetic resource conservation as well as sustainable crop production.Long-term storage induces seed viability deterioration or seed aging,accompanied by the accumulation of toxic reactive oxygen species(ROS)to suppress seed germination.Controlled deterioration treatment(CDT)is a gen-eral approach for mimicking seed aging.The transcription factor ANAC089 was previously reported to modulate seed primary germination.In this study,we evaluated the ability of ANAC089 to control seed viability during aging.Compared with that in the wild-type line,the mutation of ANAC089 significantly increased H_(2)O_(2),thereby reducing seed viability after CDT,while the overexpression of ANAC089 reduced H_(2)O_(2) and improved seed long-evity,indicating a critical role for ANAC089 in maintaining seed viability through H_(2)O_(2) signaling.A series of stu-dies have shown that ANAC089 targets and negatively regulates the level of ABI5,an important transmitter of abscisic acid(ABA)signals,to affect seed viability after CDT.Furthermore,ABI5 negatively regulated the expres-sion of VTC2,which is involved in the biosynthesis of the antioxidant ascorbic acid and H_(2)O_(2) scavenging.As a result,ANAC089 attenuates the generation of H_(2)O_(2),thereby enhancing seed viability through the ABI5-VTC2 module during the seed aging process.Taken together,our results reveal a novel mechanism by which ANAC089 enhances seed viability by coordinating ABI5 and VTC2 expression,ultimately preventing the overac-cumulation of H_(2)O_(2),which would have led to reduced seed viability.展开更多
NBS-LRR (nucleotide binding sites and leucine rich repeat) protein plays a crucial role as sentries and as defense activators in plants. The structure and function of NBS-LRR proteins are closely related. Previous art...NBS-LRR (nucleotide binding sites and leucine rich repeat) protein plays a crucial role as sentries and as defense activators in plants. The structure and function of NBS-LRR proteins are closely related. Previous articles have announced that the activated ZAR1 (HopZ-Activated Resistance 1) forms a pentamer in the plasma membrane, which is a calcium permeable channel that can trigger plant immune signaling and cell death. However, the structure of galore NBS-LRRs in Arabidopsis is not yet clear. The functional sites of distinct NBS-LRR in cells may vary. In addition, identifying pathogens and activating defense regions may occur in different subcellular compartments. Therefore, dissecting the specific structure and positioning of NBS-LRRs is an indispensable step in understanding their functions. In this article, we exploit AlphaFold to predict the structure of some designed NBS-LRRs, and utilize Agroinfiltration transient expression system, combined with biochemical fractionation, to dissect the localization of these NBS-LRR receptors from Arabidopsis. Structural data indicates that the identified NBS-LRRs share analogous conformation. Membrane fractionation assay demonstrates these NBS-LRRs are mainly associated with the membrane. These data show that the Ca2+-permeable channel activity may be evolutionarily conserved in NBS-LRR of Arabidopsis, and this study provides some reference clues for analyzing the structure and localization patterns of other plant immune receptors.展开更多
E3 ubiquitin ligases are participated in numerous processes, regulating the response to biotic and abiotic stresses. Botrytis susceptible1 interactor (BOI) is a RING (Really Interesting New Gene)-type E3 ligase that m...E3 ubiquitin ligases are participated in numerous processes, regulating the response to biotic and abiotic stresses. Botrytis susceptible1 interactor (BOI) is a RING (Really Interesting New Gene)-type E3 ligase that mediates the ubiquitination of BOS1 (Botrytis susceptible1), a transcription factor involved in stress and pathogen responses. Although BOI is an E3 ligase, there are reports to show that BOI interacts with target proteins such as DELLAs or CONSTANS to repress gibberellin responses and flowering without the degradation of the target proteins. In this article, we utilize diversified methods to comprehensively analyze the expression pattern, interaction network and function of BOI gene. Firstly, 1800 bp upstream region of BOI gene from Arabidopsis thaliana (Arabidopsis) genome was isolated, and fused GUS reporter gene. The resulting expression cassette was introduced into wild-type Arabidopsis through Agrobacterium-mediated transformation. The result demonstrated that BOI gene was expressed predominantly in leaves, siliques, young roots, and flowering tissues, indicating that BOI gene may be involved in multiple processes in plant growth and development in Arabidopsis. Besides, eight candidate interacting proteins were obtained from the Arabidopsis cDNA library via yeast two-hybrid technology, including EXO70E2 (AT5G61010), WRKY7 (AT4G24240), WRKY11 (AT4G31550), WRKY17 (AT2G24570), UBP20 (AT4G17895), L5 (AT1G12290), SAUR9 (AT4G36110) and TCP21 (AT5G08330). Functional analysis of these candidate interacting proteins manifested that they related to multiple pathways, including biological and abiotic stress, programmed cell death, protein degradation, material metabolism and transcriptional regulation. In addition, the results of the transient assay proclaimed that BOI protein affects the protein stability of EXO70E2 and L5 through its E3 ubiquitin ligase activity. Our results provide novel clues for a better understanding of molecular mechanisms underlying BOI-mediated regulations.展开更多
Fleshy fruit shape is an important external quality trait influencing the usage of fruits and consumer preference.Thus,modification of fruit shape has become one of the major objectives for crop improvement.However,th...Fleshy fruit shape is an important external quality trait influencing the usage of fruits and consumer preference.Thus,modification of fruit shape has become one of the major objectives for crop improvement.However,the underlying mechanisms of fruit shape regulation are poorly understood.In this review we summarize recent progress in the genetic basis of fleshy fruit shape regulation using tomato,cucumber,and peach as examples.Comparative analyses suggest that the OFP-TRM(OVATE Family Protein-TONNEAU1 Recruiting Motif)and IQD(IQ67 domain)pathways are probably conserved in regulating fruit shape by primarily modulating cell division patterns across fleshy fruit species.Interestingly,cucumber homologs of FRUITFULL(FUL1),CRABS CLAW(CRC)and 1-aminocyclopropane-1-carboxylate synthase 2(ACS2)were found to regulate fruit elongation.We also outline the recent progress in fruit shape regulation mediated by OFP-TRM and IQD pathways in Arabidopsis and rice,and propose that the OFP-TRM pathway and IQD pathway coordinate regulate fruit shape through integration of phytohormones,including brassinosteroids,gibberellic acids,and auxin,and microtubule organization.In addition,functional redundancy and divergence of the members of each of the OFP,TRM,and IQD families are also shown.This review provides a general overview of current knowledge in fruit shape regulation and discusses the possible mechanisms that need to be addressed in future studies.展开更多
EARLY FLOWERING 3(ELF3),a light zeitnehmer(time-taker)gene,regulates circadian rhythm and photoperiodic flowering in Arabidopsis,rice,and barley.The three orthologs of ELF3(TaELF3-1AL,TaELF3-1BL,and TaELF3-1DL)have be...EARLY FLOWERING 3(ELF3),a light zeitnehmer(time-taker)gene,regulates circadian rhythm and photoperiodic flowering in Arabidopsis,rice,and barley.The three orthologs of ELF3(TaELF3-1AL,TaELF3-1BL,and TaELF3-1DL)have been identified in wheat too,and one gene,TaELF3-1DL,has been associated with heading date.However,the basic characteristics of these three genes and the roles of the other two genes,TaELF3-1BL and,TaELF3-1AL,remain unknown.Therefore,the present study obtained the coding sequences of the three orthologs(TaELF3-1AL,TaELF3-1BL,and TaELF3-1DL)of ELF3 from bread wheat and characterized them and investigated the role of TaELF3-1BL in Arabidopsis.Protein sequence comparison revealed similarities among the three TaELF3 genes of wheat;however,they were different from the Arabidopsis ELF3.Real-time quantitative PCR revealed TaELF3 expression in all wheat tissues tested,with the highest expression in young spikes;the three genes showed rhythmic expression patterns also.Furthermore,the overexpression of the TaELF3-1BL gene in Arabidopsis delayed flowering,indicating their importance in flowering.Subsequent overexpression of TaELF3-1BL in the Arabidopsis ELF3 nonfunctional mutant(elf3 mutant)eliminated its early flowering phenotype,and slightly delayed flowering.The wild-type Arabidopsis overexpressing TaELF3-1BL demonstrated reduced expression levels of flowering-related genes,such as CONSTANS(AtCO),FLOWERING LOCUS T(AtFT),and GIGANTEA(AtGI).Thus,the study characterized the three TaELF3 genes and associated TaELF3-1BL with flowering in Arabidopsis,suggesting a role in regulating flowering in wheat too.These findings provide a basis for further research on TaELF3 functions in wheat.展开更多
Mechanical stimulation of plants can be caused by various abiotic and biotic environmental factors.Apart from the negative consequences,it can also cause positive changes,such as acclimatization of plants to stress co...Mechanical stimulation of plants can be caused by various abiotic and biotic environmental factors.Apart from the negative consequences,it can also cause positive changes,such as acclimatization of plants to stress conditions.Therefore,it is necessary to study the physiological and biochemical mechanisms underlying the response of plants to mechanical stimulation.Our aim was to evaluate the response of model plant Arabidopsis thaliana to a moderate force of 5 N(newton)for 20 s,which could be compared with the pressure caused by animal movement and weather conditions such as heavy rain.Mechanically stimulated leaves were sampled 1 h after exposure and after a recovery period of 20 h.To study a possible systemic response,unstimulated leaves of treated plants were collected 20 h after exposure alongside the stimulated leaves from the same plants.The effect of stimulation was assessed by measuring oxidative stress parameters,antioxidant enzymes activity,total phenolics,and photosynthetic performance.Stimulated leaves showed increased lipid peroxidation 1 h after treatment and increased superoxide dismutase activity and phenolic oxidation rate after a 20-h recovery period.Considering photosynthetic performance after the 20-h recovery period,the effective quantum yield of the photosystem II was lower in the stimulated leaves,whereas photochemical quenching was lower in the unstimulated leaves of the treated plants.Nonphotochemical quenching was lower in the stimulated leaves 1 h after treatment.Our study suggested that plants sensed moderate force,but it did not induce pronounced change in metabolism or photosynthetic performance.Principal component analysis distinguished three groups–leaves of untreated plants,leaves analysed 1 h after stimulation,while stimulated and unstimulated leaves of treated plants analysed 20 h after treatment formed together the third group.Observed grouping of stimulated and unstimulated leaves of treated plants could indicate signal transduction from the stimulated to distant leaves,that is,a systemic response to a local application of mechanical stimuli.展开更多
Glucosinolates and their hydrolysis products, found in plants of the order Brassicales, are well-known for their defensive properties against insect herbivores. Arabidopsis thaliana (Col-0) genetic lines with mutation...Glucosinolates and their hydrolysis products, found in plants of the order Brassicales, are well-known for their defensive properties against insect herbivores. Arabidopsis thaliana (Col-0) genetic lines with mutations that modify the type of glucosinolates (i.e. myb28myb29 and cyp79B2cyp79B3 are deficient in the production of aliphatic and indolyl glucosinolates, respectively) make it possible to test for the specific effects of these secondary chemicals on insect herbivores. The Pad3 mutant (deficient in camalexin), which has a role in resistance to pathogens, was also tested. Likewise, the effects of different glucosinolate hydrolysis products can be evaluated using genetically modified (GM) lines of the wild type Col-0 ecotype, which naturally produces isothiocyanates. These GM lines include the nitrile-producing 35S: ESP and the double knockout tgg1tgg2, which virtually lacks hydrolysis products. In both no-choice and choice experiments, the crucifer specialist Pieris rapae was virtually unaffected by differences in the type of glucosinolates or hydrolysis products. In contrast, the generalist insect Spodoptera exigua had statistically significant increases in pupae/adult weight and faster developmental times when reared on mutants deficient in the production of aliphatic and indolyl glucosinolates and their hydrolysis products. There were no differences in the performance of either insect species when reared on wild type Col-0 or Pad3. Results from feeding choice trials showed that Pieris rapae had no statistically significant preference for any of the genetic lines. In contrast, Spodoptera exigua had a significant feeding preference for the double mutant tgg1tgg2. This study provides evidence that variation in the type of glucosinolates and their hydrolysis products can influence insect performance and feeding choices, and that responses are species-specific.展开更多
[Objective] The 15urpose was to seek for the different phenotypes between wild type and Arabidopsis Mutants in response to CO2. [Method] The epidermis bioassays and seed germination test were carried out to analyze th...[Objective] The 15urpose was to seek for the different phenotypes between wild type and Arabidopsis Mutants in response to CO2. [Method] The epidermis bioassays and seed germination test were carried out to analyze the physiological characteristics of two Arabidopsis mu- tants and their wild type. [Result] There existed distinct differences in stomata apertures, water loss and leaf temperature compared with wild type except for stomata density. In addition, seed germination test on the medium indicated that cdfl was insensitive to ABA, mannitol and NaCI, but cdsl performed contrary to cdil. [ Conclusion] There are some different physiological characteristics between wild type and mutants.展开更多
[Objective] The aim was to introduce a rapid DNA extraction method for PCR detection of Arabidopsis thaliana.[Method] Through the improvement of conventional DNA extraction method,a rapid Arabidopsis thaliana DNA extr...[Objective] The aim was to introduce a rapid DNA extraction method for PCR detection of Arabidopsis thaliana.[Method] Through the improvement of conventional DNA extraction method,a rapid Arabidopsis thaliana DNA extraction method was obtained.With randomly selected Arabidopsis thaliana transgenic strains and mutants as samples,the method was verified.[Result] After electrophoresis,UV absorption detection,it was found that DNA samples are complete and less pollution,and the result of PCR amplification objective fragment was good which proved DNA is suitable as a template for PCR reaction.After PCR detection,positive plants gene amplified bands were clear,without false-positive,and the test results were satisfactory.[Conclusion] The method is suitable for rapid extraction of Arabidopsis thaliana DNA and PCR detection.展开更多
[Objective] The paper aimed to study effects of drought stress simulated by PEG on glucosinolates content in Arabidopsis thaliana.[Method] Drought stress was simulated by PEG-6000,ecological seeds of Arabidopsis thali...[Objective] The paper aimed to study effects of drought stress simulated by PEG on glucosinolates content in Arabidopsis thaliana.[Method] Drought stress was simulated by PEG-6000,ecological seeds of Arabidopsis thaliana were cultivated by the control group and drought treatment group respectively,Physical signs of Arabidopsis thaliana and contents of glucosinolates were determined after 0,4,5,6,7 d treatment.[Result] The results showed that leaf water content of rosette leaves was obviously decreased,leaf relative conductivity (characterized by membrane permeability) and the concentration of MDA increased,the extent of damage increased with the increased time.Content of total glucosinolate,aliphatic glucosinolate and indole glucosinolate increased got their maximum after 5 days treatment,and rapidly decreased after 6 and 7 days of treatment,even much lower than the control group.Each kind of glucosinolate changed with difference from each other.4MSOB which made the most proportion of the total glucosinolate changed consistently with the total glucosinolate and difference significant.As a whole,aliphatic glucosinolates were more sensitive to drought than indole glucosinolate.The proportion of some kind glucosinolate,like 4MSOB varied had correlation with the content change.[Conclusion] Drought stress had an effects on the contents of total glucosinolate,aliphatic glucosinolate and indole glucosinolate,which made the glucosinolate participated in defense response of plant to the outside of drought stress,but long-term drought stress in leaves was not conducive to the accumulation of glucosinolates.展开更多
The ultrastructures of the root protophleom sieve element at different developmental stages of Arabidopsis thaliana L. were investigated using the technique of high pressure freezing and freeze substitution fixing spe...The ultrastructures of the root protophleom sieve element at different developmental stages of Arabidopsis thaliana L. were investigated using the technique of high pressure freezing and freeze substitution fixing specimen. The results show that in the development of the sieve elements, the nuclei undergo typical characteristics of the programmed cell death (PCD): the nuclear envelopes form emboli, the chromatin condenses and aggregates towards the nuclear envelope, which degrades and fully disappears later. Before the nucleus degradation, neither the nuclear envelope undulation, nucleus lobe nor marked dilation (or bleb) of perinuclear space could be observed. In the cytoplasm of the mature sieve element, there are starch-like granules separately sheathed with a layer of membrane and usually with mitochondria around. These gnanules seem to provide substrates to mitochondria in their function. Small vacuoles originate from endoplasmic reticulum (ER), and no bigger vacuole was found.展开更多
[Objective] The aim of this study was to investigate the effects of salt stress on cell expansion in Arabidopsis thaliana rosette leaves.[Method] Arabidopsis seedlings were treated by sodium chloride at the concentrat...[Objective] The aim of this study was to investigate the effects of salt stress on cell expansion in Arabidopsis thaliana rosette leaves.[Method] Arabidopsis seedlings were treated by sodium chloride at the concentration of 0,100 or 150 mmol/L. At the 7th and 14th d of treatment,with nail enamel printing mark method and computer software,the leaf blades area and abaxial epidermal pavement cells area was measured and compared using statistical analysis in Excel. [Result] The growth of Arabidopsis rosette leaves was inhibited under salt stress. Leaves treated for 7 or 14 d expanded less compared with controls. The salt-mediated decrease in leaf expansion is associated with a decrease in abaxial pavement cell expansion. [Conclusion] The decreased leaf and epidermal cell expansion under salt stress is the most important characteristic of plant physiological response to salt stress.展开更多
Ultrastructural changes in the sieve element and dense cells of nectariferous tissue during the development of floral nectary in Arabidopsis thaliana L. were investigated with transmission electron microscopy. Samples...Ultrastructural changes in the sieve element and dense cells of nectariferous tissue during the development of floral nectary in Arabidopsis thaliana L. were investigated with transmission electron microscopy. Samples were prepared with high pressure freezing and freeze substitution techniques. The ultrastructure of dense cell was similar to that of sieve element at its early developmental stage. With the concurrent agglutination of chromatin in the nucleus, the abnormal location of organelles and the high density of cytoplasm, the ultrastructural characteristics in die dense cells of the nectariferous tissue and in the sieve element are matched with those of the programmed cell death in animal and plant reported in recent years. The disorganization of nucleus and most organelles in the differentiation of sieve elements and dense cells is closely associated with the transportation and modification of pre-nectar and the transference of nectar. This suggests that the cytological changes in sieve element and nectariferous tissue are closely associated with the nectary functional activities.展开更多
[Objective]Analysis of FLC sequence that Vernalization-related genes in Arabidopsis.[Method]Advance through natural populations of Arabidopsis QTL analysis of vernalization response was found on chromosome 5 of Arabid...[Objective]Analysis of FLC sequence that Vernalization-related genes in Arabidopsis.[Method]Advance through natural populations of Arabidopsis QTL analysis of vernalization response was found on chromosome 5 of Arabidopsis thaliana have a flowering-related QTL,this test is to use sequence analysis to determine whether it is with the FLC gene homology.[Result]Arabidopsis thaliana,Italy and Sweden in the 27th,No.461,p.501,p.638,p.738,No.884 different base.While these bases are different,but the codon encoding the first nine amino acids out of the first 167 amino acids,the first 246 amino acids,due to codon degeneracy,encode proteins that are the same.[Conclusion] Arabidopsis has a rich genetic diversity,the FLC gene is highly conserved sequence length,base variable sites rich degenerate codons encoding the same amino acids they are not affect the growth of Arabidopsis thaliana.This indicates that the Arabidopsis genome sequence will be the environment.展开更多
Potassium transporters play crucial roles in K^+ uptake and translocation in plants. However, so far little is known about the regulatory mechanism of potassium transporters. Here, we show that a Shaker-like potassiu...Potassium transporters play crucial roles in K^+ uptake and translocation in plants. However, so far little is known about the regulatory mechanism of potassium transporters. Here, we show that a Shaker-like potassium channel AtKC1, encoded by the AtLKT1 gene cloned from the Arabidopsis thaliana low-K^+ (LK)-tolerant mutant Atlktl, significantly regulates AKTl-mediated K^+ uptake under LK conditions. Under LK conditions, the Atkcl mutants maintained their root growth, whereas wild-type plants stopped their root growth. Lesion of AtKC1 significantly enhanced the tolerance of the Atkcl mutants to LK stress and markedly increased K^+ uptake and K^+ accumulation in the Atkclmutant roots under LK conditions. Electrophysiological results showed that AtKC1 inhibited the AKT1-mediated inward K^+ currents and negatively shifted the voltage dependence of AKT1 channels. These results demonstrate that the ‘silent' K^+ channel α-subunit AtKC1 negatively regulates the AKTl-mediated K^+ uptake in Arabidopsis roots and consequently alters the ratio of root-to-shoot under LK stress conditions.展开更多
By mRNA differential display from control versus NaCl_shocked Arabidopsis seedlings, we screened an Arabidopsis 3′ partial cDNA, which represents a gene encoding inositol 1,3,4_trisphosphate (Ins(1,3,4)P ...By mRNA differential display from control versus NaCl_shocked Arabidopsis seedlings, we screened an Arabidopsis 3′ partial cDNA, which represents a gene encoding inositol 1,3,4_trisphosphate (Ins(1,3,4)P 3) 5/6_kinase_like protein. Northern blotting analysis showed that the gene, named as AtITL1, is strongly induced by NaCl and low temperature, but not induced by drought and abscisic acid (ABA). Analysis of 5′ region of the AtITL1 found that there are dehydration_responsive element/C_repeat (DRE/CRT) cis _acting elements, but no elements related to G_box and ABRE (ABA_responsive element) in its 5′ region, which is consistent with the expression patterns of the AtITL1 independent of ABA. These results suggest that the AtITL1 may be involved in the osmotic stress response pathway independent of ABA.展开更多
[Objective] This study was conducted to investigate the regulation of heat shock factor AtHsfA1a on ascorbate peroxidase under heat stress in Arabidopsis thaliana. [Method] After heat stress treatment on transgenetic ...[Objective] This study was conducted to investigate the regulation of heat shock factor AtHsfA1a on ascorbate peroxidase under heat stress in Arabidopsis thaliana. [Method] After heat stress treatment on transgenetic A. thaliana with silenced endogenetic AtHsfA1a gene and wild A. thaliana plants as materials, the change in activity of APX enzyme was analyzed by spectrophotometry, the expression level of APX gene was investigated by real-time fluorescent quantitative PCR, and the binding condition of AtHsfAla with the promoter region of APX gene was analyzed by chromatin immunoprecipitation assay. [Result] The activity and mRNA level of APX in plants with silenced endogenetic AtHsfAla gene were higher than those in wild plants. Fragments of the promoter region of APX gene were not screened from the plants with silenced endogenetic AtHsfA1a gene, but found in wild plants. [Conclusion] This study provides a theoretical basis for the understanding of the important role of AtHsfAla in resistance to stress in plant, and is of great significance to the revealing of mechanism of resistance to stress in plant.展开更多
基金supported by the National Natural Science Foundation of China(31970289 to X.H.and 32170562 to P.L.).
文摘Seed viability is an essential feature for genetic resource conservation as well as sustainable crop production.Long-term storage induces seed viability deterioration or seed aging,accompanied by the accumulation of toxic reactive oxygen species(ROS)to suppress seed germination.Controlled deterioration treatment(CDT)is a gen-eral approach for mimicking seed aging.The transcription factor ANAC089 was previously reported to modulate seed primary germination.In this study,we evaluated the ability of ANAC089 to control seed viability during aging.Compared with that in the wild-type line,the mutation of ANAC089 significantly increased H_(2)O_(2),thereby reducing seed viability after CDT,while the overexpression of ANAC089 reduced H_(2)O_(2) and improved seed long-evity,indicating a critical role for ANAC089 in maintaining seed viability through H_(2)O_(2) signaling.A series of stu-dies have shown that ANAC089 targets and negatively regulates the level of ABI5,an important transmitter of abscisic acid(ABA)signals,to affect seed viability after CDT.Furthermore,ABI5 negatively regulated the expres-sion of VTC2,which is involved in the biosynthesis of the antioxidant ascorbic acid and H_(2)O_(2) scavenging.As a result,ANAC089 attenuates the generation of H_(2)O_(2),thereby enhancing seed viability through the ABI5-VTC2 module during the seed aging process.Taken together,our results reveal a novel mechanism by which ANAC089 enhances seed viability by coordinating ABI5 and VTC2 expression,ultimately preventing the overac-cumulation of H_(2)O_(2),which would have led to reduced seed viability.
文摘NBS-LRR (nucleotide binding sites and leucine rich repeat) protein plays a crucial role as sentries and as defense activators in plants. The structure and function of NBS-LRR proteins are closely related. Previous articles have announced that the activated ZAR1 (HopZ-Activated Resistance 1) forms a pentamer in the plasma membrane, which is a calcium permeable channel that can trigger plant immune signaling and cell death. However, the structure of galore NBS-LRRs in Arabidopsis is not yet clear. The functional sites of distinct NBS-LRR in cells may vary. In addition, identifying pathogens and activating defense regions may occur in different subcellular compartments. Therefore, dissecting the specific structure and positioning of NBS-LRRs is an indispensable step in understanding their functions. In this article, we exploit AlphaFold to predict the structure of some designed NBS-LRRs, and utilize Agroinfiltration transient expression system, combined with biochemical fractionation, to dissect the localization of these NBS-LRR receptors from Arabidopsis. Structural data indicates that the identified NBS-LRRs share analogous conformation. Membrane fractionation assay demonstrates these NBS-LRRs are mainly associated with the membrane. These data show that the Ca2+-permeable channel activity may be evolutionarily conserved in NBS-LRR of Arabidopsis, and this study provides some reference clues for analyzing the structure and localization patterns of other plant immune receptors.
文摘E3 ubiquitin ligases are participated in numerous processes, regulating the response to biotic and abiotic stresses. Botrytis susceptible1 interactor (BOI) is a RING (Really Interesting New Gene)-type E3 ligase that mediates the ubiquitination of BOS1 (Botrytis susceptible1), a transcription factor involved in stress and pathogen responses. Although BOI is an E3 ligase, there are reports to show that BOI interacts with target proteins such as DELLAs or CONSTANS to repress gibberellin responses and flowering without the degradation of the target proteins. In this article, we utilize diversified methods to comprehensively analyze the expression pattern, interaction network and function of BOI gene. Firstly, 1800 bp upstream region of BOI gene from Arabidopsis thaliana (Arabidopsis) genome was isolated, and fused GUS reporter gene. The resulting expression cassette was introduced into wild-type Arabidopsis through Agrobacterium-mediated transformation. The result demonstrated that BOI gene was expressed predominantly in leaves, siliques, young roots, and flowering tissues, indicating that BOI gene may be involved in multiple processes in plant growth and development in Arabidopsis. Besides, eight candidate interacting proteins were obtained from the Arabidopsis cDNA library via yeast two-hybrid technology, including EXO70E2 (AT5G61010), WRKY7 (AT4G24240), WRKY11 (AT4G31550), WRKY17 (AT2G24570), UBP20 (AT4G17895), L5 (AT1G12290), SAUR9 (AT4G36110) and TCP21 (AT5G08330). Functional analysis of these candidate interacting proteins manifested that they related to multiple pathways, including biological and abiotic stress, programmed cell death, protein degradation, material metabolism and transcriptional regulation. In addition, the results of the transient assay proclaimed that BOI protein affects the protein stability of EXO70E2 and L5 through its E3 ubiquitin ligase activity. Our results provide novel clues for a better understanding of molecular mechanisms underlying BOI-mediated regulations.
基金This work was supported by the Natural Science Foundation of Hebei Province(C2021204015)the 2021 Project for the Introduction of Oversea Students in Hebei Province(C20210510)+4 种基金science and technology research projects of colleges and universities in Hebei Province(ZD2022111)the Introduction of Talents Start-up fund of the State Key Laboratory of North China Crop Improvement and Regulation(NCCIR2020RC-13)the Introduction of Talents Start-up fund of Hebei Agricultural University(YJ2020067)the Hebei Fruit Vegetables Seed Industry Science and Technology Innovation Team Project(21326309D)the Vegetable Innovation Team Project of Hebei Modern Agricultural Industrial Technology System(HBCT2018030203).
文摘Fleshy fruit shape is an important external quality trait influencing the usage of fruits and consumer preference.Thus,modification of fruit shape has become one of the major objectives for crop improvement.However,the underlying mechanisms of fruit shape regulation are poorly understood.In this review we summarize recent progress in the genetic basis of fleshy fruit shape regulation using tomato,cucumber,and peach as examples.Comparative analyses suggest that the OFP-TRM(OVATE Family Protein-TONNEAU1 Recruiting Motif)and IQD(IQ67 domain)pathways are probably conserved in regulating fruit shape by primarily modulating cell division patterns across fleshy fruit species.Interestingly,cucumber homologs of FRUITFULL(FUL1),CRABS CLAW(CRC)and 1-aminocyclopropane-1-carboxylate synthase 2(ACS2)were found to regulate fruit elongation.We also outline the recent progress in fruit shape regulation mediated by OFP-TRM and IQD pathways in Arabidopsis and rice,and propose that the OFP-TRM pathway and IQD pathway coordinate regulate fruit shape through integration of phytohormones,including brassinosteroids,gibberellic acids,and auxin,and microtubule organization.In addition,functional redundancy and divergence of the members of each of the OFP,TRM,and IQD families are also shown.This review provides a general overview of current knowledge in fruit shape regulation and discusses the possible mechanisms that need to be addressed in future studies.
文摘EARLY FLOWERING 3(ELF3),a light zeitnehmer(time-taker)gene,regulates circadian rhythm and photoperiodic flowering in Arabidopsis,rice,and barley.The three orthologs of ELF3(TaELF3-1AL,TaELF3-1BL,and TaELF3-1DL)have been identified in wheat too,and one gene,TaELF3-1DL,has been associated with heading date.However,the basic characteristics of these three genes and the roles of the other two genes,TaELF3-1BL and,TaELF3-1AL,remain unknown.Therefore,the present study obtained the coding sequences of the three orthologs(TaELF3-1AL,TaELF3-1BL,and TaELF3-1DL)of ELF3 from bread wheat and characterized them and investigated the role of TaELF3-1BL in Arabidopsis.Protein sequence comparison revealed similarities among the three TaELF3 genes of wheat;however,they were different from the Arabidopsis ELF3.Real-time quantitative PCR revealed TaELF3 expression in all wheat tissues tested,with the highest expression in young spikes;the three genes showed rhythmic expression patterns also.Furthermore,the overexpression of the TaELF3-1BL gene in Arabidopsis delayed flowering,indicating their importance in flowering.Subsequent overexpression of TaELF3-1BL in the Arabidopsis ELF3 nonfunctional mutant(elf3 mutant)eliminated its early flowering phenotype,and slightly delayed flowering.The wild-type Arabidopsis overexpressing TaELF3-1BL demonstrated reduced expression levels of flowering-related genes,such as CONSTANS(AtCO),FLOWERING LOCUS T(AtFT),and GIGANTEA(AtGI).Thus,the study characterized the three TaELF3 genes and associated TaELF3-1BL with flowering in Arabidopsis,suggesting a role in regulating flowering in wheat too.These findings provide a basis for further research on TaELF3 functions in wheat.
基金supported by the University of Zagreb Research Grant.
文摘Mechanical stimulation of plants can be caused by various abiotic and biotic environmental factors.Apart from the negative consequences,it can also cause positive changes,such as acclimatization of plants to stress conditions.Therefore,it is necessary to study the physiological and biochemical mechanisms underlying the response of plants to mechanical stimulation.Our aim was to evaluate the response of model plant Arabidopsis thaliana to a moderate force of 5 N(newton)for 20 s,which could be compared with the pressure caused by animal movement and weather conditions such as heavy rain.Mechanically stimulated leaves were sampled 1 h after exposure and after a recovery period of 20 h.To study a possible systemic response,unstimulated leaves of treated plants were collected 20 h after exposure alongside the stimulated leaves from the same plants.The effect of stimulation was assessed by measuring oxidative stress parameters,antioxidant enzymes activity,total phenolics,and photosynthetic performance.Stimulated leaves showed increased lipid peroxidation 1 h after treatment and increased superoxide dismutase activity and phenolic oxidation rate after a 20-h recovery period.Considering photosynthetic performance after the 20-h recovery period,the effective quantum yield of the photosystem II was lower in the stimulated leaves,whereas photochemical quenching was lower in the unstimulated leaves of the treated plants.Nonphotochemical quenching was lower in the stimulated leaves 1 h after treatment.Our study suggested that plants sensed moderate force,but it did not induce pronounced change in metabolism or photosynthetic performance.Principal component analysis distinguished three groups–leaves of untreated plants,leaves analysed 1 h after stimulation,while stimulated and unstimulated leaves of treated plants analysed 20 h after treatment formed together the third group.Observed grouping of stimulated and unstimulated leaves of treated plants could indicate signal transduction from the stimulated to distant leaves,that is,a systemic response to a local application of mechanical stimuli.
文摘Glucosinolates and their hydrolysis products, found in plants of the order Brassicales, are well-known for their defensive properties against insect herbivores. Arabidopsis thaliana (Col-0) genetic lines with mutations that modify the type of glucosinolates (i.e. myb28myb29 and cyp79B2cyp79B3 are deficient in the production of aliphatic and indolyl glucosinolates, respectively) make it possible to test for the specific effects of these secondary chemicals on insect herbivores. The Pad3 mutant (deficient in camalexin), which has a role in resistance to pathogens, was also tested. Likewise, the effects of different glucosinolate hydrolysis products can be evaluated using genetically modified (GM) lines of the wild type Col-0 ecotype, which naturally produces isothiocyanates. These GM lines include the nitrile-producing 35S: ESP and the double knockout tgg1tgg2, which virtually lacks hydrolysis products. In both no-choice and choice experiments, the crucifer specialist Pieris rapae was virtually unaffected by differences in the type of glucosinolates or hydrolysis products. In contrast, the generalist insect Spodoptera exigua had statistically significant increases in pupae/adult weight and faster developmental times when reared on mutants deficient in the production of aliphatic and indolyl glucosinolates and their hydrolysis products. There were no differences in the performance of either insect species when reared on wild type Col-0 or Pad3. Results from feeding choice trials showed that Pieris rapae had no statistically significant preference for any of the genetic lines. In contrast, Spodoptera exigua had a significant feeding preference for the double mutant tgg1tgg2. This study provides evidence that variation in the type of glucosinolates and their hydrolysis products can influence insect performance and feeding choices, and that responses are species-specific.
文摘[Objective] The 15urpose was to seek for the different phenotypes between wild type and Arabidopsis Mutants in response to CO2. [Method] The epidermis bioassays and seed germination test were carried out to analyze the physiological characteristics of two Arabidopsis mu- tants and their wild type. [Result] There existed distinct differences in stomata apertures, water loss and leaf temperature compared with wild type except for stomata density. In addition, seed germination test on the medium indicated that cdfl was insensitive to ABA, mannitol and NaCI, but cdsl performed contrary to cdil. [ Conclusion] There are some different physiological characteristics between wild type and mutants.
基金Supported by National Science and Technology Support Plan of China(2006BAD21B04)Research Foundation for the Excellent Youth Scholars of Shandong Province(2004BS02013)Youth Foundation of Shandong Academy of Agricultural Sciences (2007YQN003)~~
文摘[Objective] The aim was to introduce a rapid DNA extraction method for PCR detection of Arabidopsis thaliana.[Method] Through the improvement of conventional DNA extraction method,a rapid Arabidopsis thaliana DNA extraction method was obtained.With randomly selected Arabidopsis thaliana transgenic strains and mutants as samples,the method was verified.[Result] After electrophoresis,UV absorption detection,it was found that DNA samples are complete and less pollution,and the result of PCR amplification objective fragment was good which proved DNA is suitable as a template for PCR reaction.After PCR detection,positive plants gene amplified bands were clear,without false-positive,and the test results were satisfactory.[Conclusion] The method is suitable for rapid extraction of Arabidopsis thaliana DNA and PCR detection.
文摘[Objective] The paper aimed to study effects of drought stress simulated by PEG on glucosinolates content in Arabidopsis thaliana.[Method] Drought stress was simulated by PEG-6000,ecological seeds of Arabidopsis thaliana were cultivated by the control group and drought treatment group respectively,Physical signs of Arabidopsis thaliana and contents of glucosinolates were determined after 0,4,5,6,7 d treatment.[Result] The results showed that leaf water content of rosette leaves was obviously decreased,leaf relative conductivity (characterized by membrane permeability) and the concentration of MDA increased,the extent of damage increased with the increased time.Content of total glucosinolate,aliphatic glucosinolate and indole glucosinolate increased got their maximum after 5 days treatment,and rapidly decreased after 6 and 7 days of treatment,even much lower than the control group.Each kind of glucosinolate changed with difference from each other.4MSOB which made the most proportion of the total glucosinolate changed consistently with the total glucosinolate and difference significant.As a whole,aliphatic glucosinolates were more sensitive to drought than indole glucosinolate.The proportion of some kind glucosinolate,like 4MSOB varied had correlation with the content change.[Conclusion] Drought stress had an effects on the contents of total glucosinolate,aliphatic glucosinolate and indole glucosinolate,which made the glucosinolate participated in defense response of plant to the outside of drought stress,but long-term drought stress in leaves was not conducive to the accumulation of glucosinolates.
文摘The ultrastructures of the root protophleom sieve element at different developmental stages of Arabidopsis thaliana L. were investigated using the technique of high pressure freezing and freeze substitution fixing specimen. The results show that in the development of the sieve elements, the nuclei undergo typical characteristics of the programmed cell death (PCD): the nuclear envelopes form emboli, the chromatin condenses and aggregates towards the nuclear envelope, which degrades and fully disappears later. Before the nucleus degradation, neither the nuclear envelope undulation, nucleus lobe nor marked dilation (or bleb) of perinuclear space could be observed. In the cytoplasm of the mature sieve element, there are starch-like granules separately sheathed with a layer of membrane and usually with mitochondria around. These gnanules seem to provide substrates to mitochondria in their function. Small vacuoles originate from endoplasmic reticulum (ER), and no bigger vacuole was found.
文摘[Objective] The aim of this study was to investigate the effects of salt stress on cell expansion in Arabidopsis thaliana rosette leaves.[Method] Arabidopsis seedlings were treated by sodium chloride at the concentration of 0,100 or 150 mmol/L. At the 7th and 14th d of treatment,with nail enamel printing mark method and computer software,the leaf blades area and abaxial epidermal pavement cells area was measured and compared using statistical analysis in Excel. [Result] The growth of Arabidopsis rosette leaves was inhibited under salt stress. Leaves treated for 7 or 14 d expanded less compared with controls. The salt-mediated decrease in leaf expansion is associated with a decrease in abaxial pavement cell expansion. [Conclusion] The decreased leaf and epidermal cell expansion under salt stress is the most important characteristic of plant physiological response to salt stress.
文摘Ultrastructural changes in the sieve element and dense cells of nectariferous tissue during the development of floral nectary in Arabidopsis thaliana L. were investigated with transmission electron microscopy. Samples were prepared with high pressure freezing and freeze substitution techniques. The ultrastructure of dense cell was similar to that of sieve element at its early developmental stage. With the concurrent agglutination of chromatin in the nucleus, the abnormal location of organelles and the high density of cytoplasm, the ultrastructural characteristics in die dense cells of the nectariferous tissue and in the sieve element are matched with those of the programmed cell death in animal and plant reported in recent years. The disorganization of nucleus and most organelles in the differentiation of sieve elements and dense cells is closely associated with the transportation and modification of pre-nectar and the transference of nectar. This suggests that the cytological changes in sieve element and nectariferous tissue are closely associated with the nectary functional activities.
基金Supported by the Scientific Research Foundation for the Overseas Returned Talents of Heilongjiang Province(LC08C34)Natural Science Foundation of Northeast Agricultural University~~
文摘[Objective]Analysis of FLC sequence that Vernalization-related genes in Arabidopsis.[Method]Advance through natural populations of Arabidopsis QTL analysis of vernalization response was found on chromosome 5 of Arabidopsis thaliana have a flowering-related QTL,this test is to use sequence analysis to determine whether it is with the FLC gene homology.[Result]Arabidopsis thaliana,Italy and Sweden in the 27th,No.461,p.501,p.638,p.738,No.884 different base.While these bases are different,but the codon encoding the first nine amino acids out of the first 167 amino acids,the first 246 amino acids,due to codon degeneracy,encode proteins that are the same.[Conclusion] Arabidopsis has a rich genetic diversity,the FLC gene is highly conserved sequence length,base variable sites rich degenerate codons encoding the same amino acids they are not affect the growth of Arabidopsis thaliana.This indicates that the Arabidopsis genome sequence will be the environment.
基金Acknowledgments We thank Dr Emily Liman (University of Southern California, USA) for providing the pGEMHE vector for the Xenopus oocyte experiments. We also thank Dr Richer Gaber (Northwestern Uni- versity, USA) for providing the yeast mutant strain with K+ transport deficiency. We are grateful to Dr Rainer Hedrich (University of Wurzburg, Germany) for critical discussion. This work was supported by the National Natural Science Foundation of China (grant no. 30830013 to WHW), the Beijing Municipal Education Commission (grant no. YB20081001901 to WHW) and the Program of Introducing Talents of Discipline to Universities (grant no. B06003 to WHW).
文摘Potassium transporters play crucial roles in K^+ uptake and translocation in plants. However, so far little is known about the regulatory mechanism of potassium transporters. Here, we show that a Shaker-like potassium channel AtKC1, encoded by the AtLKT1 gene cloned from the Arabidopsis thaliana low-K^+ (LK)-tolerant mutant Atlktl, significantly regulates AKTl-mediated K^+ uptake under LK conditions. Under LK conditions, the Atkcl mutants maintained their root growth, whereas wild-type plants stopped their root growth. Lesion of AtKC1 significantly enhanced the tolerance of the Atkcl mutants to LK stress and markedly increased K^+ uptake and K^+ accumulation in the Atkclmutant roots under LK conditions. Electrophysiological results showed that AtKC1 inhibited the AKT1-mediated inward K^+ currents and negatively shifted the voltage dependence of AKT1 channels. These results demonstrate that the ‘silent' K^+ channel α-subunit AtKC1 negatively regulates the AKTl-mediated K^+ uptake in Arabidopsis roots and consequently alters the ratio of root-to-shoot under LK stress conditions.
文摘By mRNA differential display from control versus NaCl_shocked Arabidopsis seedlings, we screened an Arabidopsis 3′ partial cDNA, which represents a gene encoding inositol 1,3,4_trisphosphate (Ins(1,3,4)P 3) 5/6_kinase_like protein. Northern blotting analysis showed that the gene, named as AtITL1, is strongly induced by NaCl and low temperature, but not induced by drought and abscisic acid (ABA). Analysis of 5′ region of the AtITL1 found that there are dehydration_responsive element/C_repeat (DRE/CRT) cis _acting elements, but no elements related to G_box and ABRE (ABA_responsive element) in its 5′ region, which is consistent with the expression patterns of the AtITL1 independent of ABA. These results suggest that the AtITL1 may be involved in the osmotic stress response pathway independent of ABA.
文摘[Objective] This study was conducted to investigate the regulation of heat shock factor AtHsfA1a on ascorbate peroxidase under heat stress in Arabidopsis thaliana. [Method] After heat stress treatment on transgenetic A. thaliana with silenced endogenetic AtHsfA1a gene and wild A. thaliana plants as materials, the change in activity of APX enzyme was analyzed by spectrophotometry, the expression level of APX gene was investigated by real-time fluorescent quantitative PCR, and the binding condition of AtHsfAla with the promoter region of APX gene was analyzed by chromatin immunoprecipitation assay. [Result] The activity and mRNA level of APX in plants with silenced endogenetic AtHsfAla gene were higher than those in wild plants. Fragments of the promoter region of APX gene were not screened from the plants with silenced endogenetic AtHsfA1a gene, but found in wild plants. [Conclusion] This study provides a theoretical basis for the understanding of the important role of AtHsfAla in resistance to stress in plant, and is of great significance to the revealing of mechanism of resistance to stress in plant.