In the past two decades, members of the SQUAMOSA-PROMOTER BINDING PROTEIN-LIKE （SPL） family of transcription factors, first identified in Antirrhinum majus, have emerged as pivotal regulators of diverse biological p...In the past two decades, members of the SQUAMOSA-PROMOTER BINDING PROTEIN-LIKE （SPL） family of transcription factors, first identified in Antirrhinum majus, have emerged as pivotal regulators of diverse biological processes in plants, including the timing of vegetative and reproductive phase change, leaf development, tillering/branching, plastochron, panicle/tassel architecture, fruit ripening, fertility, and response to stresses. Transcripts of a subset of SPLs are targeted for cleavage and/or translational repres- sion by microRNA156s （miR156s）. The levels of miR156s are regulated by both endogenous developmental cues and various external stimuli. Accumulating evidence shows that the regulatory circuit around the miR156/SPL module is highly conserved among phylogenetically distinct plant species, and plays impor- tant roles in regulating plant fitness, biomass, and yield. With the expanding knowledge and a mechanistic understanding of their roles and regulatory relationship, we can now harness the miR156/SPL module as a plethora of tools to genetically manipulate crops for optimal parameters in growth and development, and ultimately to maximize yield by intelligent design of crops.展开更多
During the course of their life cycles, plants undergo various morphological and physiological changes un- derlying juvenile-to-adult and adult-to-flowering phase transitions. To flower or not to flower is a key step ...During the course of their life cycles, plants undergo various morphological and physiological changes un- derlying juvenile-to-adult and adult-to-flowering phase transitions. To flower or not to flower is a key step of plasticity of a plant toward the start of its new life cycle. In addition to the previously revealed intrinsic genetic programs, exogenous cues, and endogenous cues, a class of small non-coding RNAs, microRNAs （miRNAs）, plays a key role in plants making the decision to flower by integrating into the known flowering pathways. This review highlights the age-dependent flowering pathway with a focus on a number of timing miRNAs in determining such a key process. The contributions of other miRNAs which exist mainly outside the age pathway are also discussed. Approaches to study the flowering-determining miRNAs, their inter- actions, and applications are presented.展开更多
Anthocyanins biosynthesized from the flavonoid pathway are types of pigments that are involved in the protection of poplar from biotic and abiotic stresses.Previous researchers studying anthocyanin-related transcripti...Anthocyanins biosynthesized from the flavonoid pathway are types of pigments that are involved in the protection of poplar from biotic and abiotic stresses.Previous researchers studying anthocyanin-related transcription factors and structural genes in poplar have made significant discoveries.However,little is known about the regulatory role of microRNAs in anthocyanin biosynthesis in poplar.Here,we overexpressed miR156 in poplar to study the comprehensive effects of the miR156-SPL module on the biosynthesis of anthocyanins.Small RNA sequencing analysis revealed 228 microRNAs differentially expressed in transgenic poplar plants with dramatically increased miR156 levels.Furthermore,integrated microRNAomic and transcriptomic analysis suggested that two microRNAs,miR160h,and miR858,have the potential to affect anthocyanin accumulation in poplar by regulating auxin response factors and MYB transcription factors,respectively.Additionally,the accumulation of miR160h and miR858 displayed a positive correlation with miR156 levels,suggesting a possible interaction between the miR156-SPL module and these microRNAs in poplar.Last,metabolomics analysis revealed that the levels of anthocyanins,flavones,and flavonols were substantially elevated in transgenic poplar plants overexpressing miR156 compared with the wild type,whereas the total lignin content was reduced in the transgenic plants.Taken together,our results indicate that miR156 can fine tune the anthocyanin biosynthetic pathway via multiple factors,including microRNAs,transcription factors,and the levels of structural genes,in poplar.This provides additional clues for understanding the complex regulatory network of anthocyanin biosynthesis in woody plants.展开更多
Tillering is a major determinant of rice plant architecture and grain yield.Here,we report that depletion of rice OsNRPD1a and OsNRPD1b,two orthologs of the largest subunit of RNA polymerase IV,leads to a high-tilleri...Tillering is a major determinant of rice plant architecture and grain yield.Here,we report that depletion of rice OsNRPD1a and OsNRPD1b,two orthologs of the largest subunit of RNA polymerase IV,leads to a high-tillering phenotype,in addition to dwarfism and smaller panicles.OsNRPD1a and OsNRPD1b are required for the production of 24-nt small interfering RNAs that direct DNA methylation at transposable elements(TEs)including miniature inverted-repeat TEs(MITEs).Interestingly,many genes are regulated either positively or negatively by TE methylation.Among them,OsMIR156d and OsMIR156j,which promote rice tillering,are repressed by CHH methylation at two MITEs in the promoters.By contrast,D14,which suppresses rice tillering,is activated by CHH methylation at an MITE in its downstream.Our findings reveal regulation of rice tillering by RNA-directed DNA methylation at MITEs and provide potential targets for agronomic trait enhancement through epigenome editing.展开更多
SQUAMOSA promoter binding protein-likes （SPLs） are plant-specific transcription factors playing vital regulatory roles in plant growth and development. There is no information about SPLs in Salvia miltiorrhiza （Dan...SQUAMOSA promoter binding protein-likes （SPLs） are plant-specific transcription factors playing vital regulatory roles in plant growth and development. There is no information about SPLs in Salvia miltiorrhiza （Danshen）, a significant medicinal plant widely used in Traditional Chinese medicine （TCM） for＆gt;1,700 years and an emerging model plant for TCM studies. Through genome-wide identification and subsequent molecular cloning, we identified a total 15 SmSPLs with divergent sequence features, gene structures, and motifs. Comparative analysis showed sequence conservation between SmSPLs and their Arabidopsis counterparts. A phylogenetic tree clusters SmSPLs into six groups. Many of the motifs identified commonly exist in a group/subgroup, implying their functional redundancy. Eight SmSPLs were predicted and experimental y validated to be targets of miR156/157. SmSPLs were differen-tial y expressed in various tissues of S. milltiorrhiza. The expression of miR156/157-targeted SmSPLs was increased with＆amp;nbsp;the maturation of S. miltiorrhiza, whereas the expression of miR156/157 was decreased, confirming the regulatory roles of miR156/157 in SmSPLs and suggesting the functions of SmSPLs in S. miltiorrhiza development. The expression of miR156/157 was negatively correlated with miR172 during the maturation of S. miltiorrhiza. The results indicate the significance and complexity of SmSPL-, miR156-, and miR172-mediated regula-tion of developmental timing in S. miltiorrhiza.展开更多
文摘In the past two decades, members of the SQUAMOSA-PROMOTER BINDING PROTEIN-LIKE （SPL） family of transcription factors, first identified in Antirrhinum majus, have emerged as pivotal regulators of diverse biological processes in plants, including the timing of vegetative and reproductive phase change, leaf development, tillering/branching, plastochron, panicle/tassel architecture, fruit ripening, fertility, and response to stresses. Transcripts of a subset of SPLs are targeted for cleavage and/or translational repres- sion by microRNA156s （miR156s）. The levels of miR156s are regulated by both endogenous developmental cues and various external stimuli. Accumulating evidence shows that the regulatory circuit around the miR156/SPL module is highly conserved among phylogenetically distinct plant species, and plays impor- tant roles in regulating plant fitness, biomass, and yield. With the expanding knowledge and a mechanistic understanding of their roles and regulatory relationship, we can now harness the miR156/SPL module as a plethora of tools to genetically manipulate crops for optimal parameters in growth and development, and ultimately to maximize yield by intelligent design of crops.
文摘During the course of their life cycles, plants undergo various morphological and physiological changes un- derlying juvenile-to-adult and adult-to-flowering phase transitions. To flower or not to flower is a key step of plasticity of a plant toward the start of its new life cycle. In addition to the previously revealed intrinsic genetic programs, exogenous cues, and endogenous cues, a class of small non-coding RNAs, microRNAs （miRNAs）, plays a key role in plants making the decision to flower by integrating into the known flowering pathways. This review highlights the age-dependent flowering pathway with a focus on a number of timing miRNAs in determining such a key process. The contributions of other miRNAs which exist mainly outside the age pathway are also discussed. Approaches to study the flowering-determining miRNAs, their inter- actions, and applications are presented.
基金supported by the National Key Program on Transgenic Research of China(No.2018ZX08021001-005-001)the National Natural Science Foundation of China(Nos.31672479,31701496,and 31801429)+1 种基金the Major Program of Shandong Province Natural Science Foundation(No.ZR2018ZB0213)the Assisted Project by Heilong Jiang Postdoctoral Funds for Scientific Research Initiation(LBH-Z18262).
文摘Anthocyanins biosynthesized from the flavonoid pathway are types of pigments that are involved in the protection of poplar from biotic and abiotic stresses.Previous researchers studying anthocyanin-related transcription factors and structural genes in poplar have made significant discoveries.However,little is known about the regulatory role of microRNAs in anthocyanin biosynthesis in poplar.Here,we overexpressed miR156 in poplar to study the comprehensive effects of the miR156-SPL module on the biosynthesis of anthocyanins.Small RNA sequencing analysis revealed 228 microRNAs differentially expressed in transgenic poplar plants with dramatically increased miR156 levels.Furthermore,integrated microRNAomic and transcriptomic analysis suggested that two microRNAs,miR160h,and miR858,have the potential to affect anthocyanin accumulation in poplar by regulating auxin response factors and MYB transcription factors,respectively.Additionally,the accumulation of miR160h and miR858 displayed a positive correlation with miR156 levels,suggesting a possible interaction between the miR156-SPL module and these microRNAs in poplar.Last,metabolomics analysis revealed that the levels of anthocyanins,flavones,and flavonols were substantially elevated in transgenic poplar plants overexpressing miR156 compared with the wild type,whereas the total lignin content was reduced in the transgenic plants.Taken together,our results indicate that miR156 can fine tune the anthocyanin biosynthetic pathway via multiple factors,including microRNAs,transcription factors,and the levels of structural genes,in poplar.This provides additional clues for understanding the complex regulatory network of anthocyanin biosynthesis in woody plants.
基金This work was supported by grants from National Natural Science Foundation of China(grant no.31788103)to J.L.and Y.Q.and the National Key R&D Program of China(grant no.2016YFA0500800)to Y.Q.Y.Q.is a visiting investigator of the CAS Center for Excellence in Molecular Plant Sciences.
文摘Tillering is a major determinant of rice plant architecture and grain yield.Here,we report that depletion of rice OsNRPD1a and OsNRPD1b,two orthologs of the largest subunit of RNA polymerase IV,leads to a high-tillering phenotype,in addition to dwarfism and smaller panicles.OsNRPD1a and OsNRPD1b are required for the production of 24-nt small interfering RNAs that direct DNA methylation at transposable elements(TEs)including miniature inverted-repeat TEs(MITEs).Interestingly,many genes are regulated either positively or negatively by TE methylation.Among them,OsMIR156d and OsMIR156j,which promote rice tillering,are repressed by CHH methylation at two MITEs in the promoters.By contrast,D14,which suppresses rice tillering,is activated by CHH methylation at an MITE in its downstream.Our findings reveal regulation of rice tillering by RNA-directed DNA methylation at MITEs and provide potential targets for agronomic trait enhancement through epigenome editing.
基金supported by grants from the Beijing Natural Science Foundation(Grant No.5112026 to S.L.)the Major Scientific and Technological Special Project for Significant New Drugs Creation(Grant No.2012ZX09301002-001-031 to S.L.)+2 种基金the Research Fund for the Doctoral Program of Higher Education of China(20111106110033 to S.L.)the Program for Changjiang Scholars and Innovative Research Team in University(PCSIRT,Grant No.IRT1150)the Program for Xiehe Scholars in Chinese Academy of Medical Sciences&Peking Union Medical College(to S.L.)
文摘SQUAMOSA promoter binding protein-likes （SPLs） are plant-specific transcription factors playing vital regulatory roles in plant growth and development. There is no information about SPLs in Salvia miltiorrhiza （Danshen）, a significant medicinal plant widely used in Traditional Chinese medicine （TCM） for＆gt;1,700 years and an emerging model plant for TCM studies. Through genome-wide identification and subsequent molecular cloning, we identified a total 15 SmSPLs with divergent sequence features, gene structures, and motifs. Comparative analysis showed sequence conservation between SmSPLs and their Arabidopsis counterparts. A phylogenetic tree clusters SmSPLs into six groups. Many of the motifs identified commonly exist in a group/subgroup, implying their functional redundancy. Eight SmSPLs were predicted and experimental y validated to be targets of miR156/157. SmSPLs were differen-tial y expressed in various tissues of S. milltiorrhiza. The expression of miR156/157-targeted SmSPLs was increased with＆amp;nbsp;the maturation of S. miltiorrhiza, whereas the expression of miR156/157 was decreased, confirming the regulatory roles of miR156/157 in SmSPLs and suggesting the functions of SmSPLs in S. miltiorrhiza development. The expression of miR156/157 was negatively correlated with miR172 during the maturation of S. miltiorrhiza. The results indicate the significance and complexity of SmSPL-, miR156-, and miR172-mediated regula-tion of developmental timing in S. miltiorrhiza.
