RNA-binding proteins (RBPs) play an important role in post-transcriptional gene regulation. However, the functions of RBPs in plants remain poorly understood. Maize kernel mutant dek42 has small defective kernels and ...RNA-binding proteins (RBPs) play an important role in post-transcriptional gene regulation. However, the functions of RBPs in plants remain poorly understood. Maize kernel mutant dek42 has small defective kernels and lethal seedlings. Dek42 was cloned by Mutator tag isolation and further confirmed by an independent mutant allele and clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9 materials. Dek42 encodes an RRM_RBM48 type RNA-binding protein that localizes to the nucleus. Dek42 is constitutively expressed in various maize tissues. The dek42 mutation caused a significant reduction in the accumulation of DEK42 protein in mutant kernels. RNA-seq analysis showed that the dek42 mutation significantly disturbed the expression of thousands of genes during maize kernel development. Sequence analysis also showed that the dek42 mutation significantly changed alternative splicing in expressed genes, which were especially enriched for the U12-type intron-retained type. Yeast two-hybrid screening identified SF3a1 as a DEK42-interacting protein. DEK42 also interacts with the spliceosome component U1-70K. These results suggested that DEK42 participates in the regulation of pre-messenger RNA splicing through its interaction with other spliceosome components. This study showed the function of a newly identified RBP and provided insights into alternative splicing regulation during maize kernel development.展开更多
In eukaryotes,most protein-coding genes contain introns which are removed by precursor messenger RNA(pre-mRNA) splicing.Alternative splicing is a process by which multiple messenger RNAs(mRNAs) are generated from a si...In eukaryotes,most protein-coding genes contain introns which are removed by precursor messenger RNA(pre-mRNA) splicing.Alternative splicing is a process by which multiple messenger RNAs(mRNAs) are generated from a single pre-mRNA,resulting in functionally distinct proteins.Recent genome-wide analyses of alternative splicing indicated that in higher eukaryotes alternative splicing is an important mechanism that generates proteomic complexity and regulates gene expression.Mis-regulation of splicing causes a wide range of human diseases.This review describes the current understanding of pre-mRNA splicing and the mechanisms that regulate mammalian pre-mRNA splicing.It also discusses emerging directions in the field of alternative splicing.展开更多
RNA biogenesis is essential and vital for accurate expression of genes. It is obvious that cells cannot continue normal metabolism when RNA splicing is interfered with. sgt13018 is such a mutant, with partial loss of ...RNA biogenesis is essential and vital for accurate expression of genes. It is obvious that cells cannot continue normal metabolism when RNA splicing is interfered with. sgt13018 is such a mutant, with partial loss of function of GAMETOPHYTIC FACTOR 1 （GFA1）; a gene likely involved in RNA biogenesis in Arabidopsis. The mutant is featured in the phenotype of diminished female gametophyte development at stage FG5 and is associated with the arrest of early embryo development in Arabidopsis. Bioinformatics data showed that homologs of gene GFA1 in yeast and human encode putative U5 snRNPspecific proteins required for pre-mRNA splicing. Furthermore, the result of yeast two-hybrid assay indicated that GFA1 physically interacted with AtBrr2 and AtPrp8, the putative U5 snRNP components, of Arabidopsis. This investigation suggests that GFA1 is involved in mRNA biogenesis through interaction with AtBrr2 and AtPrp8 and functions in megagametogenesis and embryogenesis in plant.展开更多
Sequences of circular RNAs(circ RNAs)produced from back-splicing of exon(s)completely overlap with those from cognate linear RNAs transcribed from the same gene loci with the exception of their back-splicing junction(...Sequences of circular RNAs(circ RNAs)produced from back-splicing of exon(s)completely overlap with those from cognate linear RNAs transcribed from the same gene loci with the exception of their back-splicing junction(BSJ)sites.Therefore,examination of global circ RNA expression from RNA-seq datasets generally relies on the detection of RNA-seq fragments spanning BSJ sites,which is different from the quantification of linear RNA expression by normalized RNA-seq fragments mapped to whole gene bodies.Thus,direct comparison of circular and linear RNA expression from the same gene loci in a genome-wide manner has remained challenging.Here,we update the previously-reported CIRCexplorer pipeline to version 3 for circular and linear RNA expression analysis from ribosomal-RNA depleted RNA-seq(CIRCexplorer3-CLEAR).A new quantitation parameter,fragments per billion mapped bases(FPB),is applied to evaluate circular and linear RNA expression individually by fragments mapped to circ RNA-specific BSJ sites or to linear RNA-specific splicing junction(SJ)sites.Comparison of circular and linear RNA expression levels is directly achieved by dividing FPBcircby FPBlinearto generate a CIRCscore,which indicates the relative circ RNA expression level using linear RNA expression level as the background.Highlyexpressed circ RNAs with low cognate linear RNA expression background can be readily identified by CIRCexplorer3-CLEAR for further investigation.CIRCexplorer3-CLEAR is publically available at https://github.com/Yang Lab/CLEAR.展开更多
Background： Cellular non-coding RNAs are extensively modified post-transcriptionally, with more than 100 chemically distinct nucleotides identified to date. In the past five years, new sequencing based methods have r...Background： Cellular non-coding RNAs are extensively modified post-transcriptionally, with more than 100 chemically distinct nucleotides identified to date. In the past five years, new sequencing based methods have revealed widespread decoration of eukaryotic messenger RNA with diverse RNA modifications whose functions in mRNA metabolism are only beginning to be known. Results： Since most of the identified mRNA modifying enzymes are present in the nucleus, these modifications have the potential to function in nuclear pre-mRNA processing including alternative splicing. Here we review recent progress towards illuminating the role of pre-mRNA modifications in splicing and highlight key areas for future investigation in this rapidly growing field. Conclusions： Future studies to identify which modifications are added to nascent pre-mRNA and to interrogate the direct effects of individual modifications are likely to reveal new mechanisms by which nuclear pre-mRNA processing is regulated.展开更多
The intron is an important component of eu-karyotic gene. Extensive studies have been conducted to get a better understanding of its structure and function. This paper presents a brief review of the structure and func...The intron is an important component of eu-karyotic gene. Extensive studies have been conducted to get a better understanding of its structure and function. This paper presents a brief review of the structure and function of introns in higher plant genes. It is shown that higher plant introns possess structural properties shared by all eukaryotic introns, however, they also exhibit a striking degree of diversity. The process of intron splicing in higher plant genes involves interaction between multiple cis -acting elements and trans-acting factors, such as 5’ splicing site, 3’ splicing site and many protein factors. The process of intron splicing is an important level at which gene expression is regulated. Especially alternative splicing of intron can regulate time and space of gene expression. In addition, some introns in higher plant genes also regulate gene expression by affecting the pattern of gene expression, enhancing the level of gene expression and driving the gene expression.展开更多
Protein arginine methylation plays important roles in diverse biological processes, but its role in regulating shoot regeneration remains elusive. In this study, we characterized the function of the protein arginine m...Protein arginine methylation plays important roles in diverse biological processes, but its role in regulating shoot regeneration remains elusive. In this study, we characterized the function of the protein arginine methyltransferase AtPRMT5 during de novo shoot regeneration in Arabidopsis. AtPRMT5 encodes a type II protein arginine methyltransferase that methylates proteins, including histories and RNA splicing factors. The frequency of shoot regeneration and the number of shoots per callus were decreased in the atprmt5 mutant compared with those in the wild type. Chromatin immunoprecipitation analysis revealed that AtPRMT5 targets KIP-RELATED PROTEINs （KRPs）, which encode the cyclin-dependent kinase inhibitors that repress the cell cycle. During shoot regeneration, the KRP transcript level increased in the atprmt5 mutant, which resulted from reduced histone H4R3 methylation in the KRP promoter. Overexpression of KRP significantly reduced the frequency of shoot regeneration and shoot number per callus. Furthermore, abnormal pre-mRNA splicing in the gene RELATED TO KPC1 （RKP）, which encodes an ubiquitin E3 ligase, was detected in the atprmt5 mutant. RKP functions in regulating KRP protein degradation, and mutation in RKP inhibited shoot regeneration. Thus, AtPRMT5 regulated shoot regeneration through histone modification-mediated KRP transcription and RKP pre-mRNA splicing. Our findings provide new insights into the function of protein arginine methylation in de novo shoot regeneration.展开更多
The objective of the present study is to establish a minigene model for studying pre-mRNA alternative splicing. To prepare the minigene DNA constructs, with human or mouse genomic DNA as templates, GluR-B , FGF-2R and...The objective of the present study is to establish a minigene model for studying pre-mRNA alternative splicing. To prepare the minigene DNA constructs, with human or mouse genomic DNA as templates, GluR-B , FGF-2R and Zis 搈inigene?fragments were amplified us-ing PCR and cloned to the eukaryotic expression vectors. The three constructed minigenes and the expression vectors of Tra2b1 and Zis2 were co-transfected in Hela cells. RT-PCR analysis was performed to semi-quantitatively determine the spliced products from the minigenes. The results demonstrated that the constructed minigenes are useful in studying the pre-mRNA al-ternative splicing in cultured cells. With the established Zis minigene, we for the first time found that Zis2 isoform regulates the alternative splicing of Zis minigene.展开更多
The splicing of many alternative exons in the precursor messenger RNA (pre-mRNA) is regulated by extracellular factors but the underlying molecular bases remain unclear. Here we report the differential regulation of B...The splicing of many alternative exons in the precursor messenger RNA (pre-mRNA) is regulated by extracellular factors but the underlying molecular bases remain unclear. Here we report the differential regulation of Bcl-x pre-mRNA splicing by extracellular factors and their distinct requirements for pre-mRNA elements. In K562 leukemia cells, treatment with interleukin-6 (IL-6) or granulocyte-macrophage colony stimulating factor (GM-CSF) reduced the proportion of the Bcl-xL variant mRNA while treatment with 12-O-tetradecanoylphorbol 13-acetate (TPA) had no effect. In U251 glioma cells, however, TPA efficiently increased the Bcl-xL level. These regulations were also seen for a transfected splicing reporter mini-gene. Further analyses of deletion mutants indicate that nucleotides 1-176 of the downstream intron are required for the IL-6 effect, whereas additional nucleotides 177-284 are essential for the GM-CSF effect. As for the TPA effect, only nucleotides 1-76 are required in the downstream intron. Thus, IL-6, GM-CSF and TPA differentially regulate Bcl-x splicing and require specific intronic pre-mRNA sequences for their respective effects.展开更多
Pre-mRNA splicing is a fundamental process required for the expression of most metazoan genes. It is carried out by the spliceosome that catalyzes the removal of non-coding intron sequences to ligate exons into mature...Pre-mRNA splicing is a fundamental process required for the expression of most metazoan genes. It is carried out by the spliceosome that catalyzes the removal of non-coding intron sequences to ligate exons into mature mRNA prior to transport and translation. The purpose of our study is to explore whether the in vitro unlabeled pre-mRNA splicing assay could be performed as an alternative method of splicing reaction other than the radiolabeled one. Two different splicing methods in vitro, 32p labeled and unlabeled pre-mRNA as the substrates in the reaction, were investigated. The radiolabeled products were visualized by autoradiography while the unlabeled products were observed by Ethidium Bromide （EB） staining. As a result, although there are more unspecific bands in the EB staining assay than 32p labeled one, the RNA products of in vitro splicing could be observed clearly. This suggests that the unlabeled pre-mRNA splicing assay can be an optional substitution for the isotope-labeled assay.展开更多
Alternative splicing(AS)regulation of pre-mRNA has been proven to be one of the fundamental layers of plant immune system.How pathogens disrupt plant AS process to suppress plant immunity by secreted effectors remain ...Alternative splicing(AS)regulation of pre-mRNA has been proven to be one of the fundamental layers of plant immune system.How pathogens disrupt plant AS process to suppress plant immunity by secreted effectors remain poorly understood.In the recent study,Gui et al.revealed that a previously identified effector PSR1 of Phytophthora interferes with host RNA splicing machinery to modulate small RNA biogenesis,leading to compromised plant immu-nity.The study provided a novel insight into the importance of AS process during pathogen-host interactions.展开更多
Pre-mRNA(messenger RNA)splicing participates in the regulation of numerous biological processes in plants.For example,alternative splicing shapes transcriptomic responses to abiotic and biotic stress,and controls deve...Pre-mRNA(messenger RNA)splicing participates in the regulation of numerous biological processes in plants.For example,alternative splicing shapes transcriptomic responses to abiotic and biotic stress,and controls developmental programs.However,no study has revealed a role for splicing in maintaining the root stem cell niche.Here,a screen for defects in root growth in Arabidopsis thaliana identified an ethyl methane sulfonate mutant defective in pre-m RNA splicing(rdm16-4).The rdm16-4 mutant displays a short-root phenotype resulting from fewer cells in the root apical meristem.The PLETHORA1(PLT1)and PLT2 transcription factor genes are important for root development and were alternatively spliced in rdm16-4 mutants,resulting in a disordered root stem cell niche and retarded root growth.The root cap of rdm16-4 contained reduced levels of cytokinins,which promote differentiation in the developing root.This reduction was associated with the alternative splicing of genes encoding cytokinin signaling factors,such as ARABIDOPSIS HISTIDINE PHOSPHOTRANSFER PROTEIN5 and ARABIDOPSIS RESPONSE REGULATORS(ARR1,ARR2,and ARR11).Furthermore,expression of the full-length coding sequence of ARR1 or exogenous cytokinin application partially rescued the short-root phenotype of rdm16-4.This reveals that the RDM16-mediated alternative splicing of cytokinin signaling components contributes to root growth.展开更多
基金supported by the National Key Research and Development Program of China (2016YFD0101003)the National Natural Science Foundation of China (91635303 and 31425019)
文摘RNA-binding proteins (RBPs) play an important role in post-transcriptional gene regulation. However, the functions of RBPs in plants remain poorly understood. Maize kernel mutant dek42 has small defective kernels and lethal seedlings. Dek42 was cloned by Mutator tag isolation and further confirmed by an independent mutant allele and clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9 materials. Dek42 encodes an RRM_RBM48 type RNA-binding protein that localizes to the nucleus. Dek42 is constitutively expressed in various maize tissues. The dek42 mutation caused a significant reduction in the accumulation of DEK42 protein in mutant kernels. RNA-seq analysis showed that the dek42 mutation significantly disturbed the expression of thousands of genes during maize kernel development. Sequence analysis also showed that the dek42 mutation significantly changed alternative splicing in expressed genes, which were especially enriched for the U12-type intron-retained type. Yeast two-hybrid screening identified SF3a1 as a DEK42-interacting protein. DEK42 also interacts with the spliceosome component U1-70K. These results suggested that DEK42 participates in the regulation of pre-messenger RNA splicing through its interaction with other spliceosome components. This study showed the function of a newly identified RBP and provided insights into alternative splicing regulation during maize kernel development.
基金Supported by the Program of "one Hundred Talented people" of the Chinese Academy of Sciences
文摘In eukaryotes,most protein-coding genes contain introns which are removed by precursor messenger RNA(pre-mRNA) splicing.Alternative splicing is a process by which multiple messenger RNAs(mRNAs) are generated from a single pre-mRNA,resulting in functionally distinct proteins.Recent genome-wide analyses of alternative splicing indicated that in higher eukaryotes alternative splicing is an important mechanism that generates proteomic complexity and regulates gene expression.Mis-regulation of splicing causes a wide range of human diseases.This review describes the current understanding of pre-mRNA splicing and the mechanisms that regulate mammalian pre-mRNA splicing.It also discusses emerging directions in the field of alternative splicing.
基金Supported by grants from the Ministry of Science and Technology of China (2007CB108702)the National Natural Science Foundation of China (30425030).
文摘RNA biogenesis is essential and vital for accurate expression of genes. It is obvious that cells cannot continue normal metabolism when RNA splicing is interfered with. sgt13018 is such a mutant, with partial loss of function of GAMETOPHYTIC FACTOR 1 （GFA1）; a gene likely involved in RNA biogenesis in Arabidopsis. The mutant is featured in the phenotype of diminished female gametophyte development at stage FG5 and is associated with the arrest of early embryo development in Arabidopsis. Bioinformatics data showed that homologs of gene GFA1 in yeast and human encode putative U5 snRNPspecific proteins required for pre-mRNA splicing. Furthermore, the result of yeast two-hybrid assay indicated that GFA1 physically interacted with AtBrr2 and AtPrp8, the putative U5 snRNP components, of Arabidopsis. This investigation suggests that GFA1 is involved in mRNA biogenesis through interaction with AtBrr2 and AtPrp8 and functions in megagametogenesis and embryogenesis in plant.
基金the Strategic Priority Research Program of Chinese Academy of Sciences,China(Grant No.XDB19020104)the National Natural Science Foundation of China(Grant Nos.31730111,31925011,and 91940306)the Howard Hughes Medical Institute International Program,the United States(Grant No.55008728).
文摘Sequences of circular RNAs(circ RNAs)produced from back-splicing of exon(s)completely overlap with those from cognate linear RNAs transcribed from the same gene loci with the exception of their back-splicing junction(BSJ)sites.Therefore,examination of global circ RNA expression from RNA-seq datasets generally relies on the detection of RNA-seq fragments spanning BSJ sites,which is different from the quantification of linear RNA expression by normalized RNA-seq fragments mapped to whole gene bodies.Thus,direct comparison of circular and linear RNA expression from the same gene loci in a genome-wide manner has remained challenging.Here,we update the previously-reported CIRCexplorer pipeline to version 3 for circular and linear RNA expression analysis from ribosomal-RNA depleted RNA-seq(CIRCexplorer3-CLEAR).A new quantitation parameter,fragments per billion mapped bases(FPB),is applied to evaluate circular and linear RNA expression individually by fragments mapped to circ RNA-specific BSJ sites or to linear RNA-specific splicing junction(SJ)sites.Comparison of circular and linear RNA expression levels is directly achieved by dividing FPBcircby FPBlinearto generate a CIRCscore,which indicates the relative circ RNA expression level using linear RNA expression level as the background.Highlyexpressed circ RNAs with low cognate linear RNA expression background can be readily identified by CIRCexplorer3-CLEAR for further investigation.CIRCexplorer3-CLEAR is publically available at https://github.com/Yang Lab/CLEAR.
文摘Background： Cellular non-coding RNAs are extensively modified post-transcriptionally, with more than 100 chemically distinct nucleotides identified to date. In the past five years, new sequencing based methods have revealed widespread decoration of eukaryotic messenger RNA with diverse RNA modifications whose functions in mRNA metabolism are only beginning to be known. Results： Since most of the identified mRNA modifying enzymes are present in the nucleus, these modifications have the potential to function in nuclear pre-mRNA processing including alternative splicing. Here we review recent progress towards illuminating the role of pre-mRNA modifications in splicing and highlight key areas for future investigation in this rapidly growing field. Conclusions： Future studies to identify which modifications are added to nascent pre-mRNA and to interrogate the direct effects of individual modifications are likely to reveal new mechanisms by which nuclear pre-mRNA processing is regulated.
文摘The intron is an important component of eu-karyotic gene. Extensive studies have been conducted to get a better understanding of its structure and function. This paper presents a brief review of the structure and function of introns in higher plant genes. It is shown that higher plant introns possess structural properties shared by all eukaryotic introns, however, they also exhibit a striking degree of diversity. The process of intron splicing in higher plant genes involves interaction between multiple cis -acting elements and trans-acting factors, such as 5’ splicing site, 3’ splicing site and many protein factors. The process of intron splicing is an important level at which gene expression is regulated. Especially alternative splicing of intron can regulate time and space of gene expression. In addition, some introns in higher plant genes also regulate gene expression by affecting the pattern of gene expression, enhancing the level of gene expression and driving the gene expression.
文摘Protein arginine methylation plays important roles in diverse biological processes, but its role in regulating shoot regeneration remains elusive. In this study, we characterized the function of the protein arginine methyltransferase AtPRMT5 during de novo shoot regeneration in Arabidopsis. AtPRMT5 encodes a type II protein arginine methyltransferase that methylates proteins, including histories and RNA splicing factors. The frequency of shoot regeneration and the number of shoots per callus were decreased in the atprmt5 mutant compared with those in the wild type. Chromatin immunoprecipitation analysis revealed that AtPRMT5 targets KIP-RELATED PROTEINs （KRPs）, which encode the cyclin-dependent kinase inhibitors that repress the cell cycle. During shoot regeneration, the KRP transcript level increased in the atprmt5 mutant, which resulted from reduced histone H4R3 methylation in the KRP promoter. Overexpression of KRP significantly reduced the frequency of shoot regeneration and shoot number per callus. Furthermore, abnormal pre-mRNA splicing in the gene RELATED TO KPC1 （RKP）, which encodes an ubiquitin E3 ligase, was detected in the atprmt5 mutant. RKP functions in regulating KRP protein degradation, and mutation in RKP inhibited shoot regeneration. Thus, AtPRMT5 regulated shoot regeneration through histone modification-mediated KRP transcription and RKP pre-mRNA splicing. Our findings provide new insights into the function of protein arginine methylation in de novo shoot regeneration.
基金This work was supported by the National Natural Science Foundation of China(Grant No.30070242)Scientific Foundation for Youth in Life Sciences,Fudan University.
文摘The objective of the present study is to establish a minigene model for studying pre-mRNA alternative splicing. To prepare the minigene DNA constructs, with human or mouse genomic DNA as templates, GluR-B , FGF-2R and Zis 搈inigene?fragments were amplified us-ing PCR and cloned to the eukaryotic expression vectors. The three constructed minigenes and the expression vectors of Tra2b1 and Zis2 were co-transfected in Hela cells. RT-PCR analysis was performed to semi-quantitatively determine the spliced products from the minigenes. The results demonstrated that the constructed minigenes are useful in studying the pre-mRNA al-ternative splicing in cultured cells. With the established Zis minigene, we for the first time found that Zis2 isoform regulates the alternative splicing of Zis minigene.
文摘The splicing of many alternative exons in the precursor messenger RNA (pre-mRNA) is regulated by extracellular factors but the underlying molecular bases remain unclear. Here we report the differential regulation of Bcl-x pre-mRNA splicing by extracellular factors and their distinct requirements for pre-mRNA elements. In K562 leukemia cells, treatment with interleukin-6 (IL-6) or granulocyte-macrophage colony stimulating factor (GM-CSF) reduced the proportion of the Bcl-xL variant mRNA while treatment with 12-O-tetradecanoylphorbol 13-acetate (TPA) had no effect. In U251 glioma cells, however, TPA efficiently increased the Bcl-xL level. These regulations were also seen for a transfected splicing reporter mini-gene. Further analyses of deletion mutants indicate that nucleotides 1-176 of the downstream intron are required for the IL-6 effect, whereas additional nucleotides 177-284 are essential for the GM-CSF effect. As for the TPA effect, only nucleotides 1-76 are required in the downstream intron. Thus, IL-6, GM-CSF and TPA differentially regulate Bcl-x splicing and require specific intronic pre-mRNA sequences for their respective effects.
基金We thank Hao Zhang for technical assistance, Dr. Robin Reed for providing AdML plasmids. The work was supported by grants from National Natural Science Foundation of China （30670441, 30300070）Program for New Century Excellent Talents in University （NCET-04-0245）+1 种基金 Specialized Fund for the Doctoral Program of Higher Education （20040062003）Tianjin Municipal Science and Technology Commission （043802811）.
文摘Pre-mRNA splicing is a fundamental process required for the expression of most metazoan genes. It is carried out by the spliceosome that catalyzes the removal of non-coding intron sequences to ligate exons into mature mRNA prior to transport and translation. The purpose of our study is to explore whether the in vitro unlabeled pre-mRNA splicing assay could be performed as an alternative method of splicing reaction other than the radiolabeled one. Two different splicing methods in vitro, 32p labeled and unlabeled pre-mRNA as the substrates in the reaction, were investigated. The radiolabeled products were visualized by autoradiography while the unlabeled products were observed by Ethidium Bromide （EB） staining. As a result, although there are more unspecific bands in the EB staining assay than 32p labeled one, the RNA products of in vitro splicing could be observed clearly. This suggests that the unlabeled pre-mRNA splicing assay can be an optional substitution for the isotope-labeled assay.
基金supported by grants from the Chinese National Science Fund(32130088,31972252)C.G.has been supported by grants from the Chinese National Science Fund(32102234)+1 种基金National Postdoctoral Program for Innovative Talents(BX2021131)the China Postdoctoral Science Foundation(2020M681644).
文摘Alternative splicing(AS)regulation of pre-mRNA has been proven to be one of the fundamental layers of plant immune system.How pathogens disrupt plant AS process to suppress plant immunity by secreted effectors remain poorly understood.In the recent study,Gui et al.revealed that a previously identified effector PSR1 of Phytophthora interferes with host RNA splicing machinery to modulate small RNA biogenesis,leading to compromised plant immu-nity.The study provided a novel insight into the importance of AS process during pathogen-host interactions.
基金supported by grants from the Ministry of Science and Technology of China(2015CB942901 to ZD)the National Natural Science Foundation of China(Projects 31470371 and 31222005 to ZD)+1 种基金Project funded by China Postdoctoral Science Foundation(2018T110683 to BL)the Special Support for Post-doc Creative Funding in Shandong(201701007 to BL)。
文摘Pre-mRNA(messenger RNA)splicing participates in the regulation of numerous biological processes in plants.For example,alternative splicing shapes transcriptomic responses to abiotic and biotic stress,and controls developmental programs.However,no study has revealed a role for splicing in maintaining the root stem cell niche.Here,a screen for defects in root growth in Arabidopsis thaliana identified an ethyl methane sulfonate mutant defective in pre-m RNA splicing(rdm16-4).The rdm16-4 mutant displays a short-root phenotype resulting from fewer cells in the root apical meristem.The PLETHORA1(PLT1)and PLT2 transcription factor genes are important for root development and were alternatively spliced in rdm16-4 mutants,resulting in a disordered root stem cell niche and retarded root growth.The root cap of rdm16-4 contained reduced levels of cytokinins,which promote differentiation in the developing root.This reduction was associated with the alternative splicing of genes encoding cytokinin signaling factors,such as ARABIDOPSIS HISTIDINE PHOSPHOTRANSFER PROTEIN5 and ARABIDOPSIS RESPONSE REGULATORS(ARR1,ARR2,and ARR11).Furthermore,expression of the full-length coding sequence of ARR1 or exogenous cytokinin application partially rescued the short-root phenotype of rdm16-4.This reveals that the RDM16-mediated alternative splicing of cytokinin signaling components contributes to root growth.
