β-Amyloid(Aβ)is a specific pathological hallmark of Alzheimer's disease(AD).Because of its neurotoxicity,AD patients exhibit multiple brain dysfunctions.Disease-modifying therapy(DMT)is the central concept in th...β-Amyloid(Aβ)is a specific pathological hallmark of Alzheimer's disease(AD).Because of its neurotoxicity,AD patients exhibit multiple brain dysfunctions.Disease-modifying therapy(DMT)is the central concept in the development of AD thera-peutics today,and most DMT drugs that are currently in clinical trials are anti-Aβdrugs,such as aducanumab and lecanemab.Therefore,understanding Aβ's neurotoxic mechanism is crucial for Aβ-targeted drug development.Despite its total length of only a few dozen amino acids,Aβis incredibly diverse.In addition to the well-known Aβ_(1-42),N-terminally truncated,glutaminyl cyclase(QC)catalyzed,and pyroglutamate-modified Aβ(pEAβ)is also highly amyloidogenic and far more cytotoxic.The extracel-lular monomeric Aβ_(x-42)(x=1-11)initiates the aggregation to form fibrils and plaques and causes many abnormal cellular responses through cell membrane receptors and receptor-coupled signal pathways.These signal cascades further influence many cel-lular metabolism-related processes,such as gene expression,cell cycle,and cell fate,and ultimately cause severe neural cell damage.However,endogenous cellular anti-Aβdefense processes always accompany the Aβ-induced microenvironment alterations.Aβ-cleaving endopeptidases,Aβ-degrading ubiquitin-proteasome system(UPS),and Aβ-engulfing glial cell immune responses are all essential self-defense mechanisms that we can leverage to develop new drugs.This review discusses some of the most recent advances in understanding Aβ-centric AD mechanisms and suggests prospects for promising anti-Aβstrategies.展开更多
The research on the tire industry cluster based on life cycle theory can be carried out by a four stage periods,namely initial period,growth period,maturity period,and recession period.This paper analyzes on the possi...The research on the tire industry cluster based on life cycle theory can be carried out by a four stage periods,namely initial period,growth period,maturity period,and recession period.This paper analyzes on the possible risks taken in each life cycle period as well as proposes corresponding suggestions to strengthen the research by looking into the conditions and factors of the continuous sustainable development process in a tire industry.展开更多
As new power systems and dual carbon policies develop,virtual power plant cluster(VPPC)provides another reliable way to promote the efficient utilization of energy and solve environmental pollution problems.To solve t...As new power systems and dual carbon policies develop,virtual power plant cluster(VPPC)provides another reliable way to promote the efficient utilization of energy and solve environmental pollution problems.To solve the coordinated optimal operation and low-carbon economic operation problem in multi-virtual power plant,a multi-virtual power plant(VPP)electricity-carbon interaction optimal scheduling model considering integrated demand response(IDR)is proposed.Firstly,a multi-VPP electricity-carbon interaction framework is established.The interaction of electric energy and carbon quotas can realize energy complementarity,reduce energy waste and promote low-carbon operation.Secondly,in order to coordinate the multiple types of energy and load in VPPC to further achieve low-carbon operation,the IDR mechanism based on the user comprehensive satisfaction(UCS)of electricity,heat as well as hydrogen is designed,which can effectively maintain the UCS in the cluster within a relatively high range.Finally,the unit output scheme is formulated to minimize the total cost of VPPC and the model is solved using theCPLEX solver.The simulation results showthat the proposed method effectively promotes the coordinated operation among multi-VPP,increases the consumption rate of renewable energy sources and the economics of VPPC and reduces carbon emissions.展开更多
The rice MtN3/saliva/SWEET gene family consists of21 paralogs. However, their functions in physiological processes are largely unknown, although at least three of the 21 paralogs are used by pathogenic bacteria to inf...The rice MtN3/saliva/SWEET gene family consists of21 paralogs. However, their functions in physiological processes are largely unknown, although at least three of the 21 paralogs are used by pathogenic bacteria to infect rice.Here, we report the evolutionary features, transcriptional characteristics, and putative functions in sugar transport of this gene family. The wild rice accessions in this study included those with AA, BB, CC, BBCC, CCDD, EE, and GG genomes,which appeared approximately 0.58–14.6 million years ago.The structures, chromosomal locations, phylogenetic relationships, and homologous distribution among the accessions suggest that the number of rice MtN3/saliva/SWEET paralogs gradually increased as the Oryza genus evolved, and one third of the paralogs may have originated recently. These paralogs are differentially expressed in vegetative and reproductive tissues, in the leaf senescence process, and in signaling dependent on gibberellic acid, cytokinin, or 1-naphthalene acetic acid(an analog of auxin), suggesting that they may be associated with multiple physiological processes. Four paral ogs could transport galactose in yeast, which suggests tha they may have a similar function in rice. These results will help to elucidate their roles and biochemical functions in rice development, adaptation to environment, host-pathogen interaction, and so forth.展开更多
Histone H2B monoubiquitination (H2Bub1) plays important roles in several physiological and developmental processes, but its roles in the regulation of plant stress responses remain elusive. Here, we report that H2Bub1...Histone H2B monoubiquitination (H2Bub1) plays important roles in several physiological and developmental processes, but its roles in the regulation of plant stress responses remain elusive. Here, we report that H2Bub1 is crucially involved in abscisic acid (ABA) signaling and drought response in rice. We found that rice HISTONE MONOUBIQUITINATION2 (OsHUB2), an E3 ligase for H2Bub1, in teracted with OsbZIP46, a key transcription factor regulating ABA signaling and drought response in rice. Genetic analyses suggest that OsHUB2, upregulated by drought and ABA, positively modulates ABA sensitivity and drought resistance. The H2Bub1 levels were in creased in the target genes of OsbZIP46 under the drought stress and ABA treat- merits, which were positively correlated with their increased expression levels. Interestingly, MODD, a reported suppressor of ABA signaling and drought resistance by mediating OsbZIP46 deactivation and degradation, could reduce the H2Bub1 levels in the target genes of OsbZIP46 by recruiting a putative deubiquitinase OsOTLD1 . Suppression of OsOTLD1in vivo resulted in increased H2Bub1 levels and expression of OsbZIP46 target genes. Collectively, these fin dings established an elaborate mecha nism of histone monoubiquitination in the fine-turning of ABA signaling and drought response by balancing H2Bub1 deposition and removal.展开更多
Appearance and taste are important factors in rice(Oryza sativa) grain quality. Here, we investigated the taste scores and related eating-quality traits of533 diverse cultivars to assess the relationships between—and...Appearance and taste are important factors in rice(Oryza sativa) grain quality. Here, we investigated the taste scores and related eating-quality traits of533 diverse cultivars to assess the relationships between—and genetic basis of—rice taste and eating-quality. A genome-wide association study highlighted the Wx gene as the major factor underlying variation in taste and eating quality. Notably, a novel waxy(Wx) allele, Wx^(la), which combined two mutations from Wx^(b) and Wx^(in), exhibited a unique phenotype. Reduced GBSSI activity conferred Wx^(la) rice with both a transparent appearance and good eating quality. Haplotype analysis revealed that Wx^(la) was derived from intragenic recombination. In fact,the recombination rate at the Wx locus was estimated to be 3.34 kb/c M, which was about 75-fold higher than the genome-wide mean, indicating that intragenic recombination is a major force driving diversity at the Wx locus. Based on our results, we propose a new network for Wx evolution, noting that new Wx alleles could easily be generated by crossing genotypes with different Wx alleles. This study thus provides insights into the evolution of the Wx locus and facilitates molecular breeding for quality in rice.展开更多
Bacterial blight caused by Xanthomonas oryzae pv.oryzae(Xoo) is the most harmful bacterial disease of rice worldwide.Previously,we characterized major disease resistance(MR) gene xa25,which confers race-specific resis...Bacterial blight caused by Xanthomonas oryzae pv.oryzae(Xoo) is the most harmful bacterial disease of rice worldwide.Previously,we characterized major disease resistance(MR) gene xa25,which confers race-specific resistance to Xoo strain PXO339.The xa25 is a recessive allele of the SWEET13 locus,but SWEET13's interaction with PXO339 and how efficiently using this locus for rice breeding still need to be defined.Here we show that the SWEET 13 allele from rice Zhenshan 97 is a susceptibility gene to PXO339.Using this allele's promoter to regulate xa25 resulted in disease,suggesting that the promoter is a key determinant in SWEET13 caused disease in Zhanshan 97 after PXO339 infection.PXO339 transcriptionally induces SWEET13 to cause disease.Partial suppressing SWEET13 expression leads to a high level of resistance to PXO339.Thus,the transcriptionally suppressed SWEET13 functions as xa25 in resistance to PXO339.Hybrid rice is widely grown in many countries.However,recessive MR genes have not been efficiently used for disease resistance breeding in hybrid rice production for both parents of the hybrid have to carry the same recessive gene.However,the suppressed SWEET 13 functions dominantly,which will have advantage to improve the resistance of hybrid rice to xa25-incomptible Xoo.展开更多
Mitogen-activated protein kinase kinase kinase(MAPKKK)are the first components of MAPK cascades,which play pivotal roles in signaling during plant development and physiological processes.The genome of rice encodes 75 ...Mitogen-activated protein kinase kinase kinase(MAPKKK)are the first components of MAPK cascades,which play pivotal roles in signaling during plant development and physiological processes.The genome of rice encodes 75 MAPKKKs,of which 43 are Raf-like MAPKKKs.The functions and action modes of most of the Raf-like MAPKKKs,whether they function as bona fide MAPKKKs and which are their downstream MAPKKs,are largely unknown.Here,we identified the osmapkkk43 mutant,which conferred broad-spectrum resistance to Xanthomonas oryzae pv.oryzae(Xoo),the destructive bacterial pathogen of rice.Oryza sativa(Os)MAPKKK43 encoding a Raf-like MAPKKK was previously known as Increased Leaf Angle 1(OsILA1).Genetic analysis indicated that OsILA1 functioned as a negative regulator and acted upstream of the OsMAPKK4-OsMAPK6 cascade in rice-Xoo interactions.Unlike classical MAPKKKs,OsILA1 mainly phosphorylated the threonine 34 site at the N-terminal domain of OsMAPKK4,which possibly influenced the stability of OsMAPKK4.The N-terminal domain of OsILA1 is required for its homodimer formation and its full phosphorylation capacity.Taken together,our findings reveal that OsILA1 acts as a negative regulator of the OsMAPKK4-OsMAPK6 cascade and is involved in rice-Xoo interactions.展开更多
Rice grain oil is a valuable nutrient source.However,the genetic basis of oil biosynthesis in rice grains remains unclear.In this study,we performed a genome-wide association study on oil composition and oil concentra...Rice grain oil is a valuable nutrient source.However,the genetic basis of oil biosynthesis in rice grains remains unclear.In this study,we performed a genome-wide association study on oil composition and oil concentration in a diverse panel of 533 cultivated rice accessions.High variation for 11 oil-related traits was observed,and the oil composition of rice grains showed differentiation among the subpopulations.We identified 46 loci that are significantly associated with grain oil concentration or composition,16 of which were detected in three recombinant inbred line populations.Twenty-six candidate genes encoding enzymes involved in oil metabolism were identified from these 46 loci,four of which(PAL6,LIN6,MYR2,and ARA6)were found to contribute to natural variation in oil composition and to show differentiation among the subpopulations.Interestingly,population genetic analyses revealed that specific haplotypes of PAL6 and LIN6 have been selected in japonica rice.Based on these results,we propose a possible oil biosynthetic pathway in rice grains.Collectively,our results provide new insights into the genetic basis of oil biosynthesis in rice grains and can facilitate marker-based breeding of rice varieties with enhanced oil and grain quality.展开更多
Speciation has long been regarded as an irreversible process once the reproductive barriers had been established.However,unlike in natural populations,artificial selection might either accelerate or prevent speciation...Speciation has long been regarded as an irreversible process once the reproductive barriers had been established.However,unlike in natural populations,artificial selection might either accelerate or prevent speciation processes in domesticated species.Asian cultivated rice is a target crop for both domestication and artificial breeding;it contains two subspecies of indica and japonica,which usually produce sterile inter-subspecific hybrids due to reproductive barriers.In this study,we constructed the evolutionary trajectory of a reproductive isolation system S5,which regulates fertility in indica-japonica hybrids via three adjacent genes,based on the data of 606 accessions including two cultivated and 11 wild rice species.Although hybrid sterility haplotypes at S5 lead to establishment of a killer-protector reproductive barrier,origin of wide-compatibility haplotypes by complex hybridization and recombination provides an opposing force to reproductive isolation and thus prevents speciation during domestication.Analysis in a diallel set of 209 crosses involving 21 parents showed that the wide-compatibility genotypes largely rescued fertility of indica-japonica hybrids,indicating that the wide-compatibility gene would enable gene flow to maintain species coherence.This counteracting system indicates that combined effects of natural evolution and artificial selection may result in reversible processes of speciation in rice,which may also have implications for genetic improvement of rice.展开更多
Plants have developed various mechanisms for avoiding pathogen invasion,including resistance(R)genes.Most R genes encode nucleotide-binding domain and leucine-rich repeat containing proteins(NLRs).Here,we report the i...Plants have developed various mechanisms for avoiding pathogen invasion,including resistance(R)genes.Most R genes encode nucleotide-binding domain and leucine-rich repeat containing proteins(NLRs).Here,we report the isolation of three new bacterial blight R genes in rice,Xa1-2,Xa14,and Xa31(t),which were allelic to Xa1 and encoded atypical NLRs with unique central tandem repeats(CTRs).We also found that Xa31(t)was the same gene as Xa1-2.Although Xa1-2 and Xa14 conferred different resistance spectra,their performance could be attenuated by iTALEs,as has previously been reported for Xa1.XA1,XA1-2,XA14,and non-resistant RGAF differed mainly in the substructure of the leucine-rich repeat domain.They all contained unique CTRs and belonged to the CTR-NLRs,which existed only in Gramineae.We also found that interactions among these genes led to differing resistance performance.In conclusion,our results uncover a unique locus in rice consisting of at least three multiple alleles(Xa1,Xa1-2,and Xa14)that encode CTRNLRs and confer resistance to Xanthomonas oryzae pv.oryzae(Xoo).展开更多
Reproductive transition of grasses is characterized by switching the pattern of lateral branches,featuring the suppression of outgrowth of the subtending leaves(bracts)and rapid formation of higher-order branches in t...Reproductive transition of grasses is characterized by switching the pattern of lateral branches,featuring the suppression of outgrowth of the subtending leaves(bracts)and rapid formation of higher-order branches in the inflorescence(panicle).However,the molecular mechanisms underlying such changes remain largely unknown.Here,we show that bract suppression is required for the reproductive branching in rice.We identified a pathway involving the intrinsic time ruler microRNAI56/529,their targets SQUAMOSA PROMOTER BINDING PROTEIN LIKE(SPL)genes,NECK LEAF1(NL1),and PLASTOCHRON1(PLA1),which regulates the bract outgrowth and thus affects the pattern switch between vegetative and reproductive branching.Suppression of the bract results in global reprogramming of transcriptome and chromatin accessibility following the reproductive transition,while these processes are largely dysregu-lated in the mutants of these genes.These discoveries contribute to our understanding of the dynamic plant architecture and provide novel insights for improving crop yields.展开更多
tRNase Z(TRZ)is a ubiquitous endonuclease that removes the 30-trailer from precursor tRNAs during maturation.In yeast and animals,TRZ regulates the cell cycle via its(t)RNA processing activity;however,its physiologica...tRNase Z(TRZ)is a ubiquitous endonuclease that removes the 30-trailer from precursor tRNAs during maturation.In yeast and animals,TRZ regulates the cell cycle via its(t)RNA processing activity;however,its physiological function in higher plants has not been well characterized.This study describes the identifcation of a rice(Oryza sativa)TRZ2 mutant;plants homozygous for the osatrz2 mutation were albinos with defcient chlorophyll content.A microscopic analysis of the mutant plants revealed that the transition of proplastids to chloroplasts was arrested at an early stage,and the number and size of the plastids in callus cells was substantially decreased.A genetic complementation test and an RNA interference analysis confrmed that disruption of OsaTRZ2 was responsible for the mutant phenotype.OsaTRZ2 is expressed in all rice tissues,but is preferentially expressed in leaves,sheathes,and calli.OsaTRZ2 was subcellularly localized in chloroplasts,and displayed tRNA 30-end processing activity in both in vitro and in vivo assays.In the osatrz2 mutants,transcription of plastid-encoded and nucleus-encoded RNA polymerases was severely reduced and moderately increased,respectively.These results suggest that the tRNA 30processing activity of OsaTRZ2 contributes to chloroplast biogenesis.展开更多
基金National Institute of Neurological Disorders and Stroke,Grant/Award Number:2RF1NS095799National Natural Science Foundation of China,Grant/Award Number:31970044 and 91854115Beijing University of Technology Faculty of Environment and Life Seed Funding,Grant/Award Number:049000513202。
文摘β-Amyloid(Aβ)is a specific pathological hallmark of Alzheimer's disease(AD).Because of its neurotoxicity,AD patients exhibit multiple brain dysfunctions.Disease-modifying therapy(DMT)is the central concept in the development of AD thera-peutics today,and most DMT drugs that are currently in clinical trials are anti-Aβdrugs,such as aducanumab and lecanemab.Therefore,understanding Aβ's neurotoxic mechanism is crucial for Aβ-targeted drug development.Despite its total length of only a few dozen amino acids,Aβis incredibly diverse.In addition to the well-known Aβ_(1-42),N-terminally truncated,glutaminyl cyclase(QC)catalyzed,and pyroglutamate-modified Aβ(pEAβ)is also highly amyloidogenic and far more cytotoxic.The extracel-lular monomeric Aβ_(x-42)(x=1-11)initiates the aggregation to form fibrils and plaques and causes many abnormal cellular responses through cell membrane receptors and receptor-coupled signal pathways.These signal cascades further influence many cel-lular metabolism-related processes,such as gene expression,cell cycle,and cell fate,and ultimately cause severe neural cell damage.However,endogenous cellular anti-Aβdefense processes always accompany the Aβ-induced microenvironment alterations.Aβ-cleaving endopeptidases,Aβ-degrading ubiquitin-proteasome system(UPS),and Aβ-engulfing glial cell immune responses are all essential self-defense mechanisms that we can leverage to develop new drugs.This review discusses some of the most recent advances in understanding Aβ-centric AD mechanisms and suggests prospects for promising anti-Aβstrategies.
文摘The research on the tire industry cluster based on life cycle theory can be carried out by a four stage periods,namely initial period,growth period,maturity period,and recession period.This paper analyzes on the possible risks taken in each life cycle period as well as proposes corresponding suggestions to strengthen the research by looking into the conditions and factors of the continuous sustainable development process in a tire industry.
基金supported by the National Natural Science Foundation of China (NSFC) (Grant No.52107107).
文摘As new power systems and dual carbon policies develop,virtual power plant cluster(VPPC)provides another reliable way to promote the efficient utilization of energy and solve environmental pollution problems.To solve the coordinated optimal operation and low-carbon economic operation problem in multi-virtual power plant,a multi-virtual power plant(VPP)electricity-carbon interaction optimal scheduling model considering integrated demand response(IDR)is proposed.Firstly,a multi-VPP electricity-carbon interaction framework is established.The interaction of electric energy and carbon quotas can realize energy complementarity,reduce energy waste and promote low-carbon operation.Secondly,in order to coordinate the multiple types of energy and load in VPPC to further achieve low-carbon operation,the IDR mechanism based on the user comprehensive satisfaction(UCS)of electricity,heat as well as hydrogen is designed,which can effectively maintain the UCS in the cluster within a relatively high range.Finally,the unit output scheme is formulated to minimize the total cost of VPPC and the model is solved using theCPLEX solver.The simulation results showthat the proposed method effectively promotes the coordinated operation among multi-VPP,increases the consumption rate of renewable energy sources and the economics of VPPC and reduces carbon emissions.
基金supported by grants from the National Program of High Technology Development of China (2012AA10A303)the National Natural Science Foundation of China (J1103510)the Fundamental Research Funds for the Central Universities (2011QC068)
文摘The rice MtN3/saliva/SWEET gene family consists of21 paralogs. However, their functions in physiological processes are largely unknown, although at least three of the 21 paralogs are used by pathogenic bacteria to infect rice.Here, we report the evolutionary features, transcriptional characteristics, and putative functions in sugar transport of this gene family. The wild rice accessions in this study included those with AA, BB, CC, BBCC, CCDD, EE, and GG genomes,which appeared approximately 0.58–14.6 million years ago.The structures, chromosomal locations, phylogenetic relationships, and homologous distribution among the accessions suggest that the number of rice MtN3/saliva/SWEET paralogs gradually increased as the Oryza genus evolved, and one third of the paralogs may have originated recently. These paralogs are differentially expressed in vegetative and reproductive tissues, in the leaf senescence process, and in signaling dependent on gibberellic acid, cytokinin, or 1-naphthalene acetic acid(an analog of auxin), suggesting that they may be associated with multiple physiological processes. Four paral ogs could transport galactose in yeast, which suggests tha they may have a similar function in rice. These results will help to elucidate their roles and biochemical functions in rice development, adaptation to environment, host-pathogen interaction, and so forth.
文摘Histone H2B monoubiquitination (H2Bub1) plays important roles in several physiological and developmental processes, but its roles in the regulation of plant stress responses remain elusive. Here, we report that H2Bub1 is crucially involved in abscisic acid (ABA) signaling and drought response in rice. We found that rice HISTONE MONOUBIQUITINATION2 (OsHUB2), an E3 ligase for H2Bub1, in teracted with OsbZIP46, a key transcription factor regulating ABA signaling and drought response in rice. Genetic analyses suggest that OsHUB2, upregulated by drought and ABA, positively modulates ABA sensitivity and drought resistance. The H2Bub1 levels were in creased in the target genes of OsbZIP46 under the drought stress and ABA treat- merits, which were positively correlated with their increased expression levels. Interestingly, MODD, a reported suppressor of ABA signaling and drought resistance by mediating OsbZIP46 deactivation and degradation, could reduce the H2Bub1 levels in the target genes of OsbZIP46 by recruiting a putative deubiquitinase OsOTLD1 . Suppression of OsOTLD1in vivo resulted in increased H2Bub1 levels and expression of OsbZIP46 target genes. Collectively, these fin dings established an elaborate mecha nism of histone monoubiquitination in the fine-turning of ABA signaling and drought response by balancing H2Bub1 deposition and removal.
基金This work was supported by grants from the National Program on R&D of Transgenic Plants(2016ZX08009004)the Natural Science Foundation of China(91935303)+2 种基金the Ministry of Science and Technology(Grants 2016YFD0100501)the earmarked fund for the China Agriculture Research System(CARS-01-03)the Postdoctoral Science Foundation of China(2017M622477)。
文摘Appearance and taste are important factors in rice(Oryza sativa) grain quality. Here, we investigated the taste scores and related eating-quality traits of533 diverse cultivars to assess the relationships between—and genetic basis of—rice taste and eating-quality. A genome-wide association study highlighted the Wx gene as the major factor underlying variation in taste and eating quality. Notably, a novel waxy(Wx) allele, Wx^(la), which combined two mutations from Wx^(b) and Wx^(in), exhibited a unique phenotype. Reduced GBSSI activity conferred Wx^(la) rice with both a transparent appearance and good eating quality. Haplotype analysis revealed that Wx^(la) was derived from intragenic recombination. In fact,the recombination rate at the Wx locus was estimated to be 3.34 kb/c M, which was about 75-fold higher than the genome-wide mean, indicating that intragenic recombination is a major force driving diversity at the Wx locus. Based on our results, we propose a new network for Wx evolution, noting that new Wx alleles could easily be generated by crossing genotypes with different Wx alleles. This study thus provides insights into the evolution of the Wx locus and facilitates molecular breeding for quality in rice.
基金supported by the National Natural Science Foundation of China(31330062)the National Key Research and Development Program of Chin(2016YFD0100903)
文摘Bacterial blight caused by Xanthomonas oryzae pv.oryzae(Xoo) is the most harmful bacterial disease of rice worldwide.Previously,we characterized major disease resistance(MR) gene xa25,which confers race-specific resistance to Xoo strain PXO339.The xa25 is a recessive allele of the SWEET13 locus,but SWEET13's interaction with PXO339 and how efficiently using this locus for rice breeding still need to be defined.Here we show that the SWEET 13 allele from rice Zhenshan 97 is a susceptibility gene to PXO339.Using this allele's promoter to regulate xa25 resulted in disease,suggesting that the promoter is a key determinant in SWEET13 caused disease in Zhanshan 97 after PXO339 infection.PXO339 transcriptionally induces SWEET13 to cause disease.Partial suppressing SWEET13 expression leads to a high level of resistance to PXO339.Thus,the transcriptionally suppressed SWEET13 functions as xa25 in resistance to PXO339.Hybrid rice is widely grown in many countries.However,recessive MR genes have not been efficiently used for disease resistance breeding in hybrid rice production for both parents of the hybrid have to carry the same recessive gene.However,the suppressed SWEET 13 functions dominantly,which will have advantage to improve the resistance of hybrid rice to xa25-incomptible Xoo.
基金This work was supported by grants from the National Key Research and Development Program of China(2016YFD0100600,2016YFD 0100903)the National Natural Science Foundation of China(31821005,31772145,31822042,31871946)the Fundamental Research Funds for the Central Universities(2662019FW006).
文摘Mitogen-activated protein kinase kinase kinase(MAPKKK)are the first components of MAPK cascades,which play pivotal roles in signaling during plant development and physiological processes.The genome of rice encodes 75 MAPKKKs,of which 43 are Raf-like MAPKKKs.The functions and action modes of most of the Raf-like MAPKKKs,whether they function as bona fide MAPKKKs and which are their downstream MAPKKs,are largely unknown.Here,we identified the osmapkkk43 mutant,which conferred broad-spectrum resistance to Xanthomonas oryzae pv.oryzae(Xoo),the destructive bacterial pathogen of rice.Oryza sativa(Os)MAPKKK43 encoding a Raf-like MAPKKK was previously known as Increased Leaf Angle 1(OsILA1).Genetic analysis indicated that OsILA1 functioned as a negative regulator and acted upstream of the OsMAPKK4-OsMAPK6 cascade in rice-Xoo interactions.Unlike classical MAPKKKs,OsILA1 mainly phosphorylated the threonine 34 site at the N-terminal domain of OsMAPKK4,which possibly influenced the stability of OsMAPKK4.The N-terminal domain of OsILA1 is required for its homodimer formation and its full phosphorylation capacity.Taken together,our findings reveal that OsILA1 acts as a negative regulator of the OsMAPKK4-OsMAPK6 cascade and is involved in rice-Xoo interactions.
基金This work was supported by grants from the Ministry of Science and Technology(Grant 2016YFD0100501)the National Program on R&D of Transgenic Plants(2016ZX08009004)+3 种基金the National Natural Science Foundation of China(91935303,31821005 and 32000378)the earmarked fund for the China Agricultural Research System(CARS-01-03)the Hubei province of Science and Technology(2020BBB051)the Postdoctoral Science Foundation of China(2017M622477).
文摘Rice grain oil is a valuable nutrient source.However,the genetic basis of oil biosynthesis in rice grains remains unclear.In this study,we performed a genome-wide association study on oil composition and oil concentration in a diverse panel of 533 cultivated rice accessions.High variation for 11 oil-related traits was observed,and the oil composition of rice grains showed differentiation among the subpopulations.We identified 46 loci that are significantly associated with grain oil concentration or composition,16 of which were detected in three recombinant inbred line populations.Twenty-six candidate genes encoding enzymes involved in oil metabolism were identified from these 46 loci,four of which(PAL6,LIN6,MYR2,and ARA6)were found to contribute to natural variation in oil composition and to show differentiation among the subpopulations.Interestingly,population genetic analyses revealed that specific haplotypes of PAL6 and LIN6 have been selected in japonica rice.Based on these results,we propose a possible oil biosynthetic pathway in rice grains.Collectively,our results provide new insights into the genetic basis of oil biosynthesis in rice grains and can facilitate marker-based breeding of rice varieties with enhanced oil and grain quality.
基金This research was supported by grants from the National Natural Science Foundation of China(31991223,30800678,and 31821005)the Hubei Provincial Natural Science Foundation of China(2019CFA061)the National Program for Support of Top-notch Young Professionals.
文摘Speciation has long been regarded as an irreversible process once the reproductive barriers had been established.However,unlike in natural populations,artificial selection might either accelerate or prevent speciation processes in domesticated species.Asian cultivated rice is a target crop for both domestication and artificial breeding;it contains two subspecies of indica and japonica,which usually produce sterile inter-subspecific hybrids due to reproductive barriers.In this study,we constructed the evolutionary trajectory of a reproductive isolation system S5,which regulates fertility in indica-japonica hybrids via three adjacent genes,based on the data of 606 accessions including two cultivated and 11 wild rice species.Although hybrid sterility haplotypes at S5 lead to establishment of a killer-protector reproductive barrier,origin of wide-compatibility haplotypes by complex hybridization and recombination provides an opposing force to reproductive isolation and thus prevents speciation during domestication.Analysis in a diallel set of 209 crosses involving 21 parents showed that the wide-compatibility genotypes largely rescued fertility of indica-japonica hybrids,indicating that the wide-compatibility gene would enable gene flow to maintain species coherence.This counteracting system indicates that combined effects of natural evolution and artificial selection may result in reversible processes of speciation in rice,which may also have implications for genetic improvement of rice.
基金supported by grants from the National Natural Science Foundation of China(grant nos.31821005,31772145,and 31200912)the China Scholarship Council(file no.201908420054).
文摘Plants have developed various mechanisms for avoiding pathogen invasion,including resistance(R)genes.Most R genes encode nucleotide-binding domain and leucine-rich repeat containing proteins(NLRs).Here,we report the isolation of three new bacterial blight R genes in rice,Xa1-2,Xa14,and Xa31(t),which were allelic to Xa1 and encoded atypical NLRs with unique central tandem repeats(CTRs).We also found that Xa31(t)was the same gene as Xa1-2.Although Xa1-2 and Xa14 conferred different resistance spectra,their performance could be attenuated by iTALEs,as has previously been reported for Xa1.XA1,XA1-2,XA14,and non-resistant RGAF differed mainly in the substructure of the leucine-rich repeat domain.They all contained unique CTRs and belonged to the CTR-NLRs,which existed only in Gramineae.We also found that interactions among these genes led to differing resistance performance.In conclusion,our results uncover a unique locus in rice consisting of at least three multiple alleles(Xa1,Xa1-2,and Xa14)that encode CTRNLRs and confer resistance to Xanthomonas oryzae pv.oryzae(Xoo).
基金the National Key Research and Development Program of China(2016YFD0100903)the National Natural Science Foundation of China(31600983 and 31821005)+1 种基金the China Postdoctoral Science Foundation(2017T100564 and 2016M590699)the Earmarked Fund for the China Agricultural Research System(CARS-01-05).
文摘Reproductive transition of grasses is characterized by switching the pattern of lateral branches,featuring the suppression of outgrowth of the subtending leaves(bracts)and rapid formation of higher-order branches in the inflorescence(panicle).However,the molecular mechanisms underlying such changes remain largely unknown.Here,we show that bract suppression is required for the reproductive branching in rice.We identified a pathway involving the intrinsic time ruler microRNAI56/529,their targets SQUAMOSA PROMOTER BINDING PROTEIN LIKE(SPL)genes,NECK LEAF1(NL1),and PLASTOCHRON1(PLA1),which regulates the bract outgrowth and thus affects the pattern switch between vegetative and reproductive branching.Suppression of the bract results in global reprogramming of transcriptome and chromatin accessibility following the reproductive transition,while these processes are largely dysregu-lated in the mutants of these genes.These discoveries contribute to our understanding of the dynamic plant architecture and provide novel insights for improving crop yields.
基金supported by the 863 Project (2012AA10A303)the Fundamental Research Funds for the Central Universities (2013PY020 and 2013PY062)
文摘tRNase Z(TRZ)is a ubiquitous endonuclease that removes the 30-trailer from precursor tRNAs during maturation.In yeast and animals,TRZ regulates the cell cycle via its(t)RNA processing activity;however,its physiological function in higher plants has not been well characterized.This study describes the identifcation of a rice(Oryza sativa)TRZ2 mutant;plants homozygous for the osatrz2 mutation were albinos with defcient chlorophyll content.A microscopic analysis of the mutant plants revealed that the transition of proplastids to chloroplasts was arrested at an early stage,and the number and size of the plastids in callus cells was substantially decreased.A genetic complementation test and an RNA interference analysis confrmed that disruption of OsaTRZ2 was responsible for the mutant phenotype.OsaTRZ2 is expressed in all rice tissues,but is preferentially expressed in leaves,sheathes,and calli.OsaTRZ2 was subcellularly localized in chloroplasts,and displayed tRNA 30-end processing activity in both in vitro and in vivo assays.In the osatrz2 mutants,transcription of plastid-encoded and nucleus-encoded RNA polymerases was severely reduced and moderately increased,respectively.These results suggest that the tRNA 30processing activity of OsaTRZ2 contributes to chloroplast biogenesis.
